The dynamics, transmission, and population impacts of avian malaria in native hawaiian birds: A modeling approach

USGS Publications Warehouse

Samuel, M.D.; Hobbelen, P.H.F.; Decastro, F.; Ahumada, J.A.; Lapointe, D.A.; Atkinson, C.T.; Woodworth, B.L.; Hart, P.J.; Duffy, D.C.

2011-01-01

We developed an epidemiological model of avian malaria (Plasmodium relictum) across an altitudinal gradient on the island of Hawaii that includes the dynamics of the host, vector, and parasite. This introduced mosquito-borne disease is hypothesized to have contributed to extinctions and major shifts in the altitudinal distribution of highly susceptible native forest birds. Our goal was to better understand how biotic and abiotic factors influence the intensity of malaria transmission and impact on susceptible populations of native Hawaiian forest birds. Our model illustrates key patterns in the malaria-forest bird system: high malaria transmission in low-elevation forests with minor seasonal or annual variation in infection;episodic transmission in mid-elevation forests with site-to-site, seasonal, and annual variation depending on mosquito dynamics;and disease refugia in high-elevation forests with only slight risk of infection during summer. These infection patterns are driven by temperature and rainfall effects on parasite incubation period and mosquito dynamics across an elevational gradient and the availability of larval habitat, especially in mid-elevation forests. The results from our model suggest that disease is likely a key factor in causing population decline or restricting the distribution of many susceptible Hawaiian species and preventing the recovery of other vulnerable species. The model also provides a framework for the evaluation of factors influencing disease transmission and alternative disease control programs, and to evaluate the impact of climate change on disease cycles and bird populations. ??2011 by the Ecological Society of America.

Large-scale drivers of malaria and priority areas for prevention and control in the Brazilian Amazon region using a novel multi-pathogen geospatial model.

PubMed

Valle, Denis; Lima, Joanna M Tucker

2014-11-20

Most of the malaria burden in the Americas is concentrated in the Brazilian Amazon but a detailed spatial characterization of malaria risk has yet to be undertaken. Utilizing 2004-2008 malaria incidence data collected from six Brazilian Amazon states, large-scale spatial patterns of malaria risk were characterized with a novel Bayesian multi-pathogen geospatial model. Data included 2.4 million malaria cases spread across 3.6 million sq km. Remotely sensed variables (deforestation rate, forest cover, rainfall, dry season length, and proximity to large water bodies), socio-economic variables (rural population size, income, and literacy rate, mortality rate for children age under five, and migration patterns), and GIS variables (proximity to roads, hydro-electric dams and gold mining operations) were incorporated as covariates. Borrowing information across pathogens allowed for better spatial predictions of malaria caused by Plasmodium falciparum, as evidenced by a ten-fold cross-validation. Malaria incidence for both Plasmodium vivax and P. falciparum tended to be higher in areas with greater forest cover. Proximity to gold mining operations was another important risk factor, corroborated by a positive association between migration rates and malaria incidence. Finally, areas with a longer dry season and areas with higher average rural income tended to have higher malaria risk. Risk maps reveal striking spatial heterogeneity in malaria risk across the region, yet these mean disease risk surface maps can be misleading if uncertainty is ignored. By combining mean spatial predictions with their associated uncertainty, several sites were consistently classified as hotspots, suggesting their importance as priority areas for malaria prevention and control. This article provides several contributions. From a methodological perspective, the benefits of jointly modelling multiple pathogens for spatial predictions were illustrated. In addition, maps of mean disease risk were contrasted with that of statistically significant disease clusters, highlighting the critical importance of uncertainty in determining disease hotspots. From an epidemiological perspective, forest cover and proximity to gold mining operations were important large-scale drivers of disease risk in the region. Finally, the hotspot in Western Acre was identified as the area that should receive highest priority from the Brazilian national malaria prevention and control programme.

Characterizing Types of Human Mobility to Inform Differential and Targeted Malaria Elimination Strategies in Northeast Cambodia

PubMed Central

Peeters Grietens, Koen; Gryseels, Charlotte; Dierickx, Susan; Bannister-Tyrrell, Melanie; Trienekens, Suzan; Uk, Sambunny; Phoeuk, Pisen; Suon, Sokha; Set, Srun; Gerrets, René; Hoibak, Sarah; Muela Ribera, Joan; Hausmann-Muela, Susanna; Tho, Sochantha; Durnez, Lies; Sluydts, Vincent; d’Alessandro, Umberto; Coosemans, Marc; Erhart, Annette

2015-01-01

Human population movements currently challenge malaria elimination in low transmission foci in the Greater Mekong Subregion. Using a mixed-methods design, combining ethnography (n = 410 interviews), malariometric data (n = 4996) and population surveys (n = 824 indigenous populations; n = 704 Khmer migrants) malaria vulnerability among different types of mobile populations was researched in the remote province of Ratanakiri, Cambodia. Different structural types of human mobility were identified, showing differential risk and vulnerability. Among local indigenous populations, access to malaria testing and treatment through the VMW-system and LLIN coverage was high but control strategies failed to account for forest farmers’ prolonged stays at forest farms/fields (61% during rainy season), increasing their exposure (p = 0.002). The Khmer migrants, with low acquired immunity, active on plantations and mines, represented a fundamentally different group not reached by LLIN-distribution campaigns since they were largely unregistered (79%) and unaware of the local VMW-system (95%) due to poor social integration. Khmer migrants therefore require control strategies including active detection, registration and immediate access to malaria prevention and control tools from which they are currently excluded. In conclusion, different types of mobility require different malaria elimination strategies. Targeting mobility without an in-depth understanding of malaria risk in each group challenges further progress towards elimination. PMID:26593245

Border malaria in China: knowledge and use of personal protection by minority populations and implications for malaria control: a questionnaire-based survey.

PubMed

Moore, Sarah J; Min, Xia; Hill, Nigel; Jones, Caroline; Zaixing, Zhang; Cameron, Mary M

2008-10-01

Malaria control in remote, forested areas of the Mekong region relies on personal protection from mosquito bites. Uptake of these methods may be limited by knowledge of the link between mosquitoes and malaria as well as social and economic aspects. Understanding barriers to uptake will inform malaria control programmes on targets for improvement of delivery. A total 748 key respondents: health providers and village heads, from 187 villages and 25 different ethnic groups, were interviewed using structured questionnaires. Differences in use of personal protection, and knowledge of malaria between groups were analysed using chi-square; and binary logistic regression used for multivariate analysis. Malaria knowledge was poor with 19.4% of women and 37.5% of men linking mosquitoes with malaria, although 95.6% knew one or more methods of mosquito control. Virtually all respondents used personal protection at some time during the year; and understanding of malaria transmission was strongly associated with bednet use. Those working in forest agriculture were significantly more likely to know that mosquitoes transmit malaria but this did not translate into a significantly greater likelihood of using bednets. Furthermore, use of personal protection while woing outdoors was rare, and less than 3% of respondents knew about the insecticide impregnation of bednets. The use of bednets, synthetic repellents and mosquito coils varied between ethnic groups, but was significantly more frequent among those with higher income, more years of education and permanent housing. The reported use of repellents and coils was also more common among women despite their low knowledge of malaria transmission, and low likelihood of having heard information on malaria within the last year. The use of personal protection must be increased, particularly among outdoor workers that have higher malaria risk. However, personal protection is widely used and widely accepted to prevent nuisance biting mosquitoes, with the major barrier to use being affordability. Therefore, social marketing campaigns aimed at women and those that work outdoors that provide highly subsidised products, especially insecticide impregnation kits for bednets and hammock nets are most likely to succeed in lowering malaria morbidity among non Han-Chinese groups in rural China.

Prevalence of pox-like lesions and malaria in forest bird communitites on leeward Mauna Loa volcano, Hawaii

USGS Publications Warehouse

Atkinson, C.T.; Lease, J.K.; Dusek, Robert J.; Samuel, M.D.

2005-01-01

Introduced avian pox virus and malaria have had devastating impacts on native Hawaiian forest birds, yet little has been published about their prevalence and distribution in forest bird communities outside of windward Hawaii Island. We surveyed native and non-native forest birds for these two diseases at three different elevations on leeward Mauna Loa Volcano at the Kona Forest Unit of Hakalau Forest National Wildlife Refuge. Prevalence of malaria by both serology and microscopy varied by elevation and ranged from 28% at 710 m to 13% at 1830 m. Prevalence of pox-like lesions also varied by altitude, ranging in native species from 10% at 710 m to 2% at 1830 m. Native species at all elevations had the highest prevalence of malarial antibody and pox-like lesions. By contrast, pox-like lesions were not detected in individuals of four non-native species and only 5% of Japanese White-eye (Zosterops japonicus) was positive for malaria. A significantly high proportion of birds with pox-like lesions also had serological evidence of concurrent, chronic malarial infections, suggesting an interaction between these diseases, dual transmission of both diseases by the primary mosquito vector (Culex quinquefasciatus) or complete recovery of some pox-infected birds without loss of toes. Results from this study document high prevalence of malaria and pox at this refuge. Development of effective disease control strategies will be important for restoration of remnant populations of the endangered 'Akiapola'au (Hemignathus munroi), Hawaii Creeper (Oreomystis mana), and Hawaii 'Akepa (Loxops coccineus coccineus) that still occur on the refuge.

Ecotope-Based Entomological Surveillance and Molecular Xenomonitoring of Multidrug Resistant Malaria Parasites in Anopheles Vectors

PubMed Central

2014-01-01

The emergence and spread of multidrug resistant (MDR) malaria caused by Plasmodium falciparum or Plasmodium vivax have become increasingly important in the Greater Mekong Subregion (GMS). MDR malaria is the heritable and hypermutable property of human malarial parasite populations that can decrease in vitro and in vivo susceptibility to proven antimalarial drugs as they exhibit dose-dependent drug resistance and delayed parasite clearance time in treated patients. MDR malaria risk situations reflect consequences of the national policy and strategy as this influences the ongoing national-level or subnational-level implementation of malaria control strategies in endemic GMS countries. Based on our experience along with current literature review, the design of ecotope-based entomological surveillance (EES) and molecular xenomonitoring of MDR falciparum and vivax malaria parasites in Anopheles vectors is proposed to monitor infection pockets in transmission control areas of forest and forest fringe-related malaria, so as to bridge malaria landscape ecology (ecotope and ecotone) and epidemiology. Malaria ecotope and ecotone are confined to a malaria transmission area geographically associated with the infestation of Anopheles vectors and particular environments to which human activities are related. This enables the EES to encompass mosquito collection and identification, salivary gland DNA extraction, Plasmodium- and species-specific identification, molecular marker-based PCR detection methods for putative drug resistance genes, and data management. The EES establishes strong evidence of Anopheles vectors carrying MDR P. vivax in infection pockets epidemiologically linked with other data obtained during which a course of follow-up treatment of the notified P. vivax patients receiving the first-line treatment was conducted. For regional and global perspectives, the EES would augment the epidemiological surveillance and monitoring of MDR falciparum and vivax malaria parasites in hotspots or suspected areas established in most endemic GMS countries implementing the National Malaria Control Programs, in addition to what is guided by the World Health Organization. PMID:25349605

Epidemiology of forest malaria in Central Vietnam: the hidden parasite reservoir.

PubMed

Thanh, Pham Vinh; Van Hong, Nguyen; Van Van, Nguyen; Van Malderen, Carine; Obsomer, Valérie; Rosanas-Urgell, Anna; Grietens, Koen Peeters; Xa, Nguyen Xuan; Bancone, Germana; Chowwiwat, Nongnud; Duong, Tran Thanh; D'Alessandro, Umberto; Speybroeck, Niko; Erhart, Annette

2015-02-19

After successfully reducing the malaria burden to pre-elimination levels over the past two decades, the national malaria programme in Vietnam has recently switched from control to elimination. However, in forested areas of Central Vietnam malaria elimination is likely to be jeopardized by the high occurrence of asymptomatic and submicroscopic infections as shown by previous reports. This paper presents the results of a malaria survey carried out in a remote forested area of Central Vietnam where we evaluated malaria prevalence and risk factors for infection. After a full census (four study villages = 1,810 inhabitants), the study population was screened for malaria infections by standard microscopy and, if needed, treated according to national guidelines. An additional blood sample on filter paper was also taken in a random sample of the population for later polymerase chain reaction (PCR) and more accurate estimation of the actual burden of malaria infections. The risk factor analysis for malaria infections was done using survey multivariate logistic regression as well as the classification and regression tree method (CART). A total of 1,450 individuals were screened. Malaria prevalence by microscopy was 7.8% (ranging from 3.9 to 10.9% across villages) mostly Plasmodium falciparum (81.4%) or Plasmodium vivax (17.7%) mono-infections; a large majority (69.9%) was asymptomatic. By PCR, the prevalence was estimated at 22.6% (ranging from 16.4 to 42.5%) with a higher proportion of P. vivax mono-infections (43.2%). The proportion of sub-patent infections increased with increasing age and with decreasing prevalence across villages. The main risk factors were young age, village, house structure, and absence of bed net. This study confirmed that in Central Vietnam a substantial part of the human malaria reservoir is hidden. Additional studies are urgently needed to assess the contribution of this hidden reservoir to the maintenance of malaria transmission. Such evidence will be crucial for guiding elimination strategies.

Can lowland dry forests represent a refuge from avian malaria for native Hawaiian birds?

USGS Publications Warehouse

Tucker-Mohl, Katherine; Hart, Patrick; Atkinson, Carter T.

2010-01-01

Hawaii's native birds have become increasingly threatened over the past century. Introduced mosquito borne diseases such as avian malaria may be responsible for the near absence of endemic Hawaiian forest birds in low-elevation habitats. The recent recognition that some native Hawaiian forest birds may be repopulating moist lowland habitats as a result of evolved resistance to this disease has increased the conservation value of these areas. Here, we investigate whether remnant low elevation dry forests on Hawaii Island provide natural 'refuges' from mosquito-transmitted malaria by nature of their low rainfall and absence of suitable natural sources of water for mosquito breeding. Unlike lowland wet forests where high rates of disease transmission may be selecting for disease resistance, lowland dry forests may provide some refuge for native forest birds without natural resistance to malaria. We mistnetted forest birds in two lowland dry forests and tested all native birds by microscopy and serology for avian malaria caused by the Plasmodium relictum parasite. We also conducted surveys for standing water and mosquito larvae. Overall prevalence of infections with Plasmodium relictum in the Hawaii Amakihi Hemignathus virens virens was 15%. Most infected birds had lowlevel parasitemias, suggesting chronic infections. Although avian malaria is present in these lowland dry forest Amakihi populations, infection rates are significantly lower than in wet forest populations at similar elevations. Sources of breeding mosquitoes in these forests appeared to be largely anthropogenic; thus, there is potential to manage dry forests as mosquito-free habitat for Hawaii Amakihi and other Hawaiian forest birds.

A global assessment of closed forests, deforestation and malaria risk

PubMed Central

GUERRA, C. A.; SNOW, R. W.; HAY, S. I.

2011-01-01

Global environmental change is expected to affect profoundly the transmission of the parasites that cause human malaria. Amongst the anthropogenic drivers of change, deforestation is arguably the most conspicuous, and its rate is projected to increase in the coming decades. The canonical epidemiological understanding is that deforestation increases malaria risk in Africa and the Americas and diminishes it in South–east Asia. Partial support for this position is provided here, through a systematic review of the published literature on deforestation, malaria and the relevant vector bionomics. By using recently updated boundaries for the spatial limits of malaria and remotely-sensed estimates of tree cover, it has been possible to determine the population at risk of malaria in closed forest, at least for those malaria-endemic countries that lie within the main blocks of tropical forest. Closed forests within areas of malaria risk cover approximately 1.5 million km2 in the Amazon region, 1.4 million km2 in Central Africa, 1.2 million km2 in the Western Pacific, and 0.7 million km2 in South–east Asia. The corresponding human populations at risk of malaria within these forests total 11.7 million, 18.7 million, 35.1 million and 70.1 million, respectively. By coupling these numbers with the country-specific rates of deforestation, it has been possible to rank malaria-endemic countries according to their potential for change in the population at risk of malaria, as the result of deforestation. The on-going research aimed at evaluating these relationships more quantitatively, through the Malaria Atlas Project (MAP), is highlighted. PMID:16630376

Tackling the malaria problem in the South-East Asia Region: need for a change in policy?

PubMed

Bharati, Kaushik; Ganguly, N K

2013-01-01

Malaria is largely neglected in the South-East Asia Region (SEAR), although it has the highest number of people susceptible to the disease. Malaria in the SEAR exhibits special epidemiological characteristics such as "forest malaria" and malaria due to migration across international borders. The Greater Mekong Subregion (GMS) has been a focal-point for the emergence of drug resistant malaria. With the recent emergence of artemisinin resistance, coupled with the limited availability of insecticides, malaria control efforts in the SEAR face a steep challenge. Indirect man-made factors such as climate change, as well as direct man-made factors such as the circulation of counterfeit drugs have added to the problem. Increased monitoring, surveillance, pharmacovigilance as well as cross-border collaboration are required to address these problems. Regional networking and data-sharing will keep all stakeholders updated about the status of various malaria control programmes in the SEAR. Cutting-edge technologies such as GIS/GPS (geographical information system/global positioning system) systems and mobile phones can provide information in "real-time". A holistic and sustained approach to malaria control by integrated vector management (IVM) is suggested, in which all the stakeholder countries work collaboratively as a consortium. This approach will address the malaria problem in a collective manner so that malaria control can be sustained over time.

Joint malaria surveys lead towards improved cross-border cooperation between Savannakhet province, Laos and Quang Tri province, Vietnam.

PubMed

Pongvongsa, Tiengkham; Ha, Hoang; Thanh, Le; Marchand, Ron P; Nonaka, Daisuke; Tojo, Bumpei; Phongmany, Panom; Moji, Kazuhiko; Kobayashi, Jun

2012-08-03

In Savannakhet province, Laos and Quang Tri province, Vietnam, malaria is still an important health problem and most cases are found in the mountainous, forested border areas where ethnic minority groups live. The objectives of this study were to obtain a better joint understanding of the malaria situation along the border and, on the basis of that, improve malaria control methods through better cooperation between the two countries. Fourteen villages in Savannakhet and 22 villages in Quang Tri were randomly selected within 5 km from the border where a blood survey for microscopic diagnosis (n = 1256 and n = 1803, respectively), household interviews (n = 400, both sides) and vector surveys were conducted between August and October 2010. Satellite images were used to examine the forest density around the study villages. Malaria prevalence was significantly higher in Laos (5.2%) than in Vietnam (1.8%) and many other differences were found over the short distance across the border. Bed net coverage was high (> 90%) in both Laos and Vietnam but, while in Laos more than 60% of the nets were long-lasting insecticide-treated, Vietnam used indoor residual spraying in this area and the nets were untreated. Anopheles mosquitoes were more abundant in Laos than in Vietnam, especially many Anopheles dirus were captured in indoor light traps while none were collected in Vietnam. The forest cover was higher around the Lao than the Vietnamese villages. After this study routine exchange of malaria surveillance data was institutionalized and for the first time indoor residual spraying was applied in some Lao villages. The abundance of indoor-collected An. dirus on the Laos side raises doubts about the effectiveness of a sole reliance on long-lasting insecticide-treated nets in this area. Next to strengthening the early detection, correct diagnosis and prompt, adequate treatment of malaria infections, it is recommended to test focal indoor residual spraying and the promotion of insect repellent use in the early evening as additional vector interventions. Conducting joint malaria surveys by staff of two countries proved to be effective in stimulating better collaboration and improve cross-border malaria control.

Deforestation and Malaria on the Amazon Frontier: Larval Clustering of Anopheles darlingi (Diptera: Culicidae) Determines Focal Distribution of Malaria

PubMed Central

Barros, Fábio S. M.; Honório, Nildimar A.

2015-01-01

We performed bimonthly mosquito larval collections during 1 year, in an agricultural settlement in the Brazilian Amazon, as well as an analysis of malaria incidence in neighboring houses. Water collections located at forest fringes were more commonly positive for Anopheles darlingi larvae and Kulldorff spatial analysis pinpointed significant larval clusters at sites directly beneath forest fringes, which were called larval “hotspots.” Remote sensing identified 43 “potential” hotspots. Sampling of these areas revealed an 85.7% positivity rate for A. darlingi larvae. Malaria was correlated with shorter distances to potential hotpots and settlers living within 400 m of potential hotspots had a 2.60 higher risk of malaria. Recently arrived settlers, usually located closer to the tip of the triangularly shaped deforestation imprints of side roads, may be more exposed to malaria due to their proximity to the forest fringe. As deforestation progresses, transmission decreases. However, forest remnants inside deforested areas conferred an increased risk of malaria. We propose a model for explaining frontier malaria in the Amazon: because of adaptation of A. darlingi to the forest fringe ecotone, humans are exposed to an increased transmission risk when in proximity to these areas, especially when small dams are created on naturally running water collections. PMID:26416110

Avian malaria Plasmodium relictum in native Hawaiian forest birds: epizootiology and demographic impacts on ‵apapane Himatione sanguinea

USGS Publications Warehouse

Atkinson, Carter T.; Samuel, Michael D.

2010-01-01

The role of introduced avian malaria Plasmodium relictum in the decline and extinction of native Hawaiian forest birds has become a classic example of the potential effect of invasive diseases on biological diversity of naïve populations. However, empirical evidence describing the impact of avian malaria on fitness of Hawai‵i's endemic forest birds is limited, making it difficult to determine the importance of disease among the suite of potential limiting factors affecting the distribution and abundance of this threatened avifauna. We combined epidemiological force-of-infection with multistate capture––recapture models to evaluate a 7-year longitudinal study of avian malaria in ‵apapane, a relatively common native honeycreeper within mid-elevation Hawaiian forests. We found that malaria transmission was seasonal in this mid-elevation forest; transmission peaked during fall and during some years produced epizootic mortality events. Estimated annual mortality of hatch-year birds typically exceeded 50% and mortality of adults exceeded 25% during epizootics. The substantial impact of avian malaria on this relatively common native species demonstrates the key role this disease has played in the decline and extinction of Hawaiian forest birds.

Tackling the malaria problem in the South-East Asia Region: Need for a change in policy?

PubMed Central

Bharati, Kaushik; Ganguly, N. K.

2013-01-01

Malaria is largely neglected in the South-East Asia Region (SEAR), although it has the highest number of people susceptible to the disease. Malaria in the SEAR exhibits special epidemiological characteristics such as “forest malaria” and malaria due to migration across international borders. The Greater Mekong Subregion (GMS) has been a focal-point for the emergence of drug resistant malaria. With the recent emergence of artemisinin resistance, coupled with the limited availability of insecticides, malaria control efforts in the SEAR face a steep challenge. Indirect man-made factors such as climate change, as well as direct man-made factors such as the circulation of counterfeit drugs have added to the problem. Increased monitoring, surveillance, pharmacovigilance as well as cross-border collaboration are required to address these problems. Regional networking and data-sharing will keep all stakeholders updated about the status of various malaria control programmes in the SEAR. Cutting-edge technologies such as GIS/GPS (geographical information system/global positioning system) systems and mobile phones can provide information in “real-time”. A holistic and sustained approach to malaria control by integrated vector management (IVM) is suggested, in which all the stakeholder countries work collaboratively as a consortium. This approach will address the malaria problem in a collective manner so that malaria control can be sustained over time. PMID:23481050

Malaria in Brazil, Colombia, Peru and Venezuela: current challenges in malaria control and elimination.

PubMed

Recht, Judith; Siqueira, André M; Monteiro, Wuelton M; Herrera, Sonia M; Herrera, Sócrates; Lacerda, Marcus V G

2017-07-04

In spite of significant progress towards malaria control and elimination achieved in South America in the 2000s, this mosquito-transmitted tropical disease remains an important public health concern in the region. Most malaria cases in South America come from Amazon rain forest areas in northern countries, where more than half of malaria is caused by Plasmodium vivax, while Plasmodium falciparum malaria incidence has decreased in recent years. This review discusses current malaria data, policies and challenges in four South American Amazon countries: Brazil, Colombia, Peru and the Bolivarian Republic of Venezuela. Challenges to continuing efforts to further decrease malaria incidence in this region include: a significant increase in malaria cases in recent years in Venezuela, evidence of submicroscopic and asymptomatic infections, peri-urban malaria, gold mining-related malaria, malaria in pregnancy, glucose-6-phosphate dehydrogenase (G6PD) deficiency and primaquine use, and possible under-detection of Plasmodium malariae. Some of these challenges underscore the need to implement appropriate tools and procedures in specific regions, such as a field-compatible molecular malaria test, a P. malariae-specific test, malaria diagnosis and appropriate treatment as part of regular antenatal care visits, G6PD test before primaquine administration for P. vivax cases (with weekly primaquine regimen for G6PD deficient individuals), single low dose of primaquine for P. falciparum malaria in Colombia, and national and regional efforts to contain malaria spread in Venezuela urgently needed especially in mining areas. Joint efforts and commitment towards malaria control and elimination should be strategized based on examples of successful regional malaria fighting initiatives, such as PAMAFRO and RAVREDA/AMI.

Fighting malaria in Madhya Pradesh (Central India): Are we loosing the battle?

PubMed Central

Singh, Neeru; Dash, Aditya P; Thimasarn, Krongthong

2009-01-01

Malaria control in Madhya Pradesh is complex because of vast tracts of forest with tribal settlement. Fifty four million individuals of various ethnic origins, accounting for 8% of the total population of India, contributed 30% of total malaria cases, 60% of total falciparum cases and 50% of malaria deaths in the country. Ambitious goals to control tribal malaria by launching "Enhanced Malaria Control Project" (EMCP) by the National Vector Borne Disease Control Programme (NVBDCP), with the World Bank assistance, became effective in September 1997 in eight north Indian states. Under EMCP, the programme used a broader mix of new interventions, i.e. insecticide-treated bed nets, spraying houses with effective residual insecticides, use of larvivorous fishes, rapid diagnostic tests for prompt diagnosis, treatment of the sick with effective radical treatment and increased public awareness and IEC. However, the challenge is to scale up these services. A retrospective analysis of data on malaria morbidity and associated mortality reported under the existing surveillance system of the Madhya Pradesh (Central India) for the years 1996–2007 was carried out to determine the impact of EMCP on malaria morbidity and associated mortality. Analysis revealed that despite the availability of effective intervention tools for the prevention and control of malaria, falciparum malaria remains uncontrolled and deaths due to malaria have increased. Precisely, the aim of this epidemiological analysis is to draw lessons applicable to all international aid efforts, bureaucracy, policy makers and programme managers in assessing its project performance as a new Global Malaria Action Plan is launched with ambitious goal of reducing malaria and its elimination by scaling up the use of existing tools. PMID:19419588

Risk factors for Plasmodium vivax infection in the Lacandon forest, southern Mexico.

PubMed

Danis-Lozano, R; Rodriguez, M H; Gonzalez-Ceron, L; Hernandez-Avila, M

1999-06-01

A study was conducted to characterize the risk of Plasmodium vivax infection in the Lacandon forest, southern Mexico. Blood samples and questionnaire data were collected in 1992. Malaria cases (n = 137) were identified by the presence of symptoms and a positive thick blood smear. The control group included individuals with negative antibody titres and no history of malaria (n = 4994). From 7628 individuals studied, 1006 had anti-P. vivax antibodies. Seroprevalence increased with age. Risk factors associated with infection included: place of birth outside the village of residence (odds ratio, OR 11.67; 95% CI 5.21-26.11); no use of medical services (OR 4.69, 95% CI 3.01-7.29), never using bed-nets (OR 3.98, 95 % CI 1.23-12.86) and poor knowledge of malaria transmission, prevention and treatment (OR 2.30, 95 % CI 1.30-4.07). Health education represents the best recommendation for controlling the disease in the area.

Risk factors for Plasmodium vivax infection in the Lacandon forest, southern Mexico.

PubMed Central

Danis-Lozano, R.; Rodriguez, M. H.; Gonzalez-Ceron, L.; Hernandez-Avila, M.

1999-01-01

A study was conducted to characterize the risk of Plasmodium vivax infection in the Lacandon forest, southern Mexico. Blood samples and questionnaire data were collected in 1992. Malaria cases (n = 137) were identified by the presence of symptoms and a positive thick blood smear. The control group included individuals with negative antibody titres and no history of malaria (n = 4994). From 7628 individuals studied, 1006 had anti-P. vivax antibodies. Seroprevalence increased with age. Risk factors associated with infection included: place of birth outside the village of residence (odds ratio, OR 11.67; 95% CI 5.21-26.11); no use of medical services (OR 4.69, 95% CI 3.01-7.29), never using bed-nets (OR 3.98, 95 % CI 1.23-12.86) and poor knowledge of malaria transmission, prevention and treatment (OR 2.30, 95 % CI 1.30-4.07). Health education represents the best recommendation for controlling the disease in the area. PMID:10459651

Risk Factors for Border Malaria in a Malaria Elimination Setting: A Retrospective Case-Control Study in Yunnan, China

PubMed Central

Xu, Jian-Wei; Liu, Hui; Zhang, Yu; Guo, Xiang-Rui; Wang, Jia-Zhi

2015-01-01

A retrospective case-control study was conducted to identify risk factors for border malaria in a malaria elimination setting of Yunnan Province, China. The study comprised 214 cases and 428 controls. The controls were individually matched to the cases on the basis of residence, age, and gender. In addition, statistical associations are based on matched analyses. The frequencies of imported, male, adult, and vivax malaria cases were respectively 201 (93.9%), 194 (90.7%), 210 (98.1%), and 176 (82.2%). Overnight stay in Myanmar within the prior month was independently associated with malaria infection (odds ratio [OR] 159.5, 95% confidence interval [CI] 75.1–338.9). In particular, stays in lowland and foothill (OR 5.5, 95% CI 2.5–11.8) or mid-hill (OR 42.8, 95% CI 5.1–319.8) areas, or near streamlets (OR 15.3, 95% CI 4.3–55.2) or paddy field or pools (OR10.1, 95% CI 4.4–55.8) were found to be independently associated with malaria. Neither forest exposure nor use of vector control measures was associated with malaria. In conclusion, travel to lowland and foothill or mid-hill hyperendemic areas, especially along the waterside in Myanmar, was found to be the highest risk factor for malaria. In considering the limitations of the study, further investigations are needed to identify the major determinants of malaria risk and develop new strategies for malaria elimination on China-Myanmar border. PMID:25601994

Biodiversity can help prevent malaria outbreaks in tropical forests.

PubMed

Laporta, Gabriel Zorello; Lopez de Prado, Paulo Inácio Knegt; Kraenkel, Roberto André; Coutinho, Renato Mendes; Sallum, Maria Anice Mureb

2013-01-01

Plasmodium vivax is a widely distributed, neglected parasite that can cause malaria and death in tropical areas. It is associated with an estimated 80-300 million cases of malaria worldwide. Brazilian tropical rain forests encompass host- and vector-rich communities, in which two hypothetical mechanisms could play a role in the dynamics of malaria transmission. The first mechanism is the dilution effect caused by presence of wild warm-blooded animals, which can act as dead-end hosts to Plasmodium parasites. The second is diffuse mosquito vector competition, in which vector and non-vector mosquito species compete for blood feeding upon a defensive host. Considering that the World Health Organization Malaria Eradication Research Agenda calls for novel strategies to eliminate malaria transmission locally, we used mathematical modeling to assess those two mechanisms in a pristine tropical rain forest, where the primary vector is present but malaria is absent. The Ross-Macdonald model and a biodiversity-oriented model were parameterized using newly collected data and data from the literature. The basic reproduction number ([Formula: see text]) estimated employing Ross-Macdonald model indicated that malaria cases occur in the study location. However, no malaria cases have been reported since 1980. In contrast, the biodiversity-oriented model corroborated the absence of malaria transmission. In addition, the diffuse competition mechanism was negatively correlated with the risk of malaria transmission, which suggests a protective effect provided by the forest ecosystem. There is a non-linear, unimodal correlation between the mechanism of dead-end transmission of parasites and the risk of malaria transmission, suggesting a protective effect only under certain circumstances (e.g., a high abundance of wild warm-blooded animals). To achieve biological conservation and to eliminate Plasmodium parasites in human populations, the World Health Organization Malaria Eradication Research Agenda should take biodiversity issues into consideration.

Joint malaria surveys lead towards improved cross-border cooperation between Savannakhet province, Laos and Quang Tri province, Vietnam

PubMed Central

2012-01-01

Background In Savannakhet province, Laos and Quang Tri province, Vietnam, malaria is still an important health problem and most cases are found in the mountainous, forested border areas where ethnic minority groups live. The objectives of this study were to obtain a better joint understanding of the malaria situation along the border and, on the basis of that, improve malaria control methods through better cooperation between the two countries. Methods Fourteen villages in Savannakhet and 22 villages in Quang Tri were randomly selected within 5 km from the border where a blood survey for microscopic diagnosis (n = 1256 and n = 1803, respectively), household interviews (n = 400, both sides) and vector surveys were conducted between August and October 2010. Satellite images were used to examine the forest density around the study villages. Results Malaria prevalence was significantly higher in Laos (5.2%) than in Vietnam (1.8%) and many other differences were found over the short distance across the border. Bed net coverage was high (> 90%) in both Laos and Vietnam but, while in Laos more than 60% of the nets were long-lasting insecticide-treated, Vietnam used indoor residual spraying in this area and the nets were untreated. Anopheles mosquitoes were more abundant in Laos than in Vietnam, especially many Anopheles dirus were captured in indoor light traps while none were collected in Vietnam. The forest cover was higher around the Lao than the Vietnamese villages. After this study routine exchange of malaria surveillance data was institutionalized and for the first time indoor residual spraying was applied in some Lao villages. Conclusions The abundance of indoor-collected An. dirus on the Laos side raises doubts about the effectiveness of a sole reliance on long-lasting insecticide-treated nets in this area. Next to strengthening the early detection, correct diagnosis and prompt, adequate treatment of malaria infections, it is recommended to test focal indoor residual spraying and the promotion of insect repellent use in the early evening as additional vector interventions. Conducting joint malaria surveys by staff of two countries proved to be effective in stimulating better collaboration and improve cross-border malaria control. PMID:22862795

Malaria vector populations across ecological zones in Guinea Conakry and Mali, West Africa.

PubMed

Coulibaly, Boubacar; Kone, Raymond; Barry, Mamadou S; Emerson, Becky; Coulibaly, Mamadou B; Niare, Oumou; Beavogui, Abdoul H; Traore, Sekou F; Vernick, Kenneth D; Riehle, Michelle M

2016-04-08

Malaria remains a pervasive public health problem in sub-Saharan West Africa. Here mosquito vector populations were explored across four sites in Mali and the Republic of Guinea (Guinea Conakry). The study samples the major ecological zones of malaria-endemic regions in West Africa within a relatively small distance. Mosquito vectors were sampled from larval pools, adult indoor resting sites, and indoor and outdoor human-host seeking adults. Mosquitoes were collected at sites spanning 350 km that represented arid savannah, humid savannah, semi-forest and deep forest ecological zones, in areas where little was previously known about malaria vector populations. 1425 mosquito samples were analysed by molecular assays to determine species, genetic attributes, blood meal sources and Plasmodium infection status. Anopheles gambiae and Anopheles coluzzii were the major anophelines represented in all collections across the ecological zones, with A. coluzzii predominant in the arid savannah and A. gambiae in the more humid sites. The use of multiple collection methodologies across the sampling sites allows assessment of potential collection bias of the different methods. The L1014F kdr insecticide resistance mutation (kdr-w) is found at high frequency across all study sites. This mutation appears to have swept almost to fixation, from low frequencies 6 years earlier, despite the absence of widespread insecticide use for vector control. Rates of human feeding are very high across ecological zones, with only small fractions of animal derived blood meals in the arid and humid savannah. About 30 % of freshly blood-fed mosquitoes were positive for Plasmodium falciparum presence, while the rate of mosquitoes with established infections was an order of magnitude lower. The study represents detailed vector characterization from an understudied area in West Africa with endemic malaria transmission. The deep forest study site includes the epicenter of the 2014 Ebola virus epidemic. With new malaria control interventions planned in Guinea, these data provide a baseline measure and an opportunity to assess the outcome of future interventions.

High Mobility and Low Use of Malaria Preventive Measures among the Jarai Male Youth along the Cambodia–Vietnam Border

PubMed Central

Gryseels, Charlotte; Peeters Grietens, Koen; Dierickx, Susan; Xuan, Xa Nguyen; Uk, Sambunny; Bannister-Tyrrell, Melanie; Trienekens, Suzan; Ribera, Joan Muela; Hausmann-Muela, Susanna; Gerrets, René; D'Alessandro, Umberto; Sochantha, Tho; Coosemans, Marc; Erhart, Annette

2015-01-01

Malaria control along the Vietnam–Cambodia border presents a challenge for both countries' malaria elimination targets as the region is forested, inhabited by ethnic minority populations, and potentially characterized by early and outdoor malaria transmission. A mixed methods study assessed the vulnerability to malaria among the Jarai population living on both sides of the border in the provinces of Ratanakiri (Cambodia) and Gia Lai (Vietnam). A qualitative study generated preliminary hypotheses that were quantified in two surveys, one targeting youth (N = 498) and the other household leaders (N = 449). Jarai male youth, especially in Cambodia, had lower uptake of preventive measures (57.4%) and more often stayed overnight in the deep forest (35.8%) compared with the female youth and the adult population. Among male youth, a high-risk subgroup was identified that regularly slept at friends' homes or outdoors, who had fewer bed nets (32.5%) that were torn more often (77.8%). The vulnerability of Jarai youth to malaria could be attributed to the transitional character of youth itself, implying less fixed sleeping arrangements in nonpermanent spaces or non-bed sites. Additional tools such as long-lasting hammock nets could be suitable as they are in line with current practices. PMID:26283747

Seasonal genetic partitioning in the neotropical malaria vector, Anopheles darlingi

PubMed Central

2014-01-01

Background Anopheles darlingi is the main malaria mosquito vector in the Amazonia region. In spite of being considered a riverine, forest-dwelling species, this mosquito is becoming more abundant in peri-urban areas, increasing malaria risk. This has been associated with human-driven environmental changes such as deforestation. Methods Microsatellites were used to characterize A. darlingi from seven localities along the Madeira River, Rondônia (Brazil), collected in the early and late periods of the rainy season. Results Two genetically distinct subpopulations were detected: one (subpopulation A) was associated with the late rainfall period and seems to be ecologically closer to the typical forest A. darlingi; the other (subpopulation B) was associated with the early rainfall period and is probably more adapted to drier conditions by exploiting permanent anthropogenic breeding sites. Results suggest also a pattern of asymmetric introgression, with more subpopulation A alleles introgressed into subpopulation B. Both subpopulations (and admixed mosquitoes) presented similar malaria infection rates, highlighting the potential for perennial malaria transmission in the region. Conclusions The co-occurrence of two genetically distinct subpopulations of A. darlingi adapted to different periods of rainfall may promote a more perennial transmission of malaria throughout the year. These findings, in a context of strong environmental impact due to deforestation and dam construction, have serious implications for malaria epidemiology and control in the Amazonian region. PMID:24885508

One-year delayed effect of fog on malaria transmission: a time-series analysis in the rain forest area of Mengla County, south-west China

PubMed Central

Tian, Linwei; Bi, Yan; Ho, Suzanne C; Liu, Wenjie; Liang, Song; Goggins, William B; Chan, Emily YY; Zhou, Shuisen; Sung, Joseph JY

2008-01-01

Background Malaria is a major public health burden in the tropics with the potential to significantly increase in response to climate change. Analyses of data from the recent past can elucidate how short-term variations in weather factors affect malaria transmission. This study explored the impact of climate variability on the transmission of malaria in the tropical rain forest area of Mengla County, south-west China. Methods Ecological time-series analysis was performed on data collected between 1971 and 1999. Auto-regressive integrated moving average (ARIMA) models were used to evaluate the relationship between weather factors and malaria incidence. Results At the time scale of months, the predictors for malaria incidence included: minimum temperature, maximum temperature, and fog day frequency. The effect of minimum temperature on malaria incidence was greater in the cool months than in the hot months. The fog day frequency in October had a positive effect on malaria incidence in May of the following year. At the time scale of years, the annual fog day frequency was the only weather predictor of the annual incidence of malaria. Conclusion Fog day frequency was for the first time found to be a predictor of malaria incidence in a rain forest area. The one-year delayed effect of fog on malaria transmission may involve providing water input and maintaining aquatic breeding sites for mosquitoes in vulnerable times when there is little rainfall in the 6-month dry seasons. These findings should be considered in the prediction of future patterns of malaria for similar tropical rain forest areas worldwide. PMID:18565224

Risk of exposure to potential vector mosquitoes for rural workers in Northern Lao PDR

PubMed Central

Thammavong, Phoutmany; Lindsay, Steve W.; Brey, Paul T.

2017-01-01

Background One major consequence of economic development in South-East Asia has been a rapid expansion of rubber plantations, in which outbreaks of dengue and malaria have occurred. Here we explored the difference in risk of exposure to potential dengue, Japanese encephalitis (JE), and malaria vectors between rubber workers and those engaged in traditional forest activities in northern Laos PDR. Methodology/Principal findings Adult mosquitoes were collected for nine months in secondary forests, mature and immature rubber plantations, and villages. Human behavior data were collected using rapid participatory rural appraisals and surveys. Exposure risk was assessed by combining vector and human behavior and calculating the basic reproduction number (R0) in different typologies. Compared to those that stayed in the village, the risk of dengue vector exposure was higher for those that visited the secondary forests during the day (odds ratio (OR) 36.0), for those living and working in rubber plantations (OR 16.2) and for those that tapped rubber (OR 3.2). Exposure to JE vectors was also higher in the forest (OR 1.4) and, similar when working (OR 1.0) and living in the plantations (OR 0.8). Exposure to malaria vectors was greater in the forest (OR 1.3), similar when working in the plantations (OR 0.9) and lower when living in the plantations (OR 0.6). R0 for dengue was >2.8 for all habitats surveyed, except villages where R0≤0.06. The main malaria vector in all habitats was Anopheles maculatus s.l. in the rainy season and An. minimus s.l. in the dry season. Conclusions/Significance The highest risk of exposure to vector mosquitoes occurred when people visit natural forests. However, since rubber workers spend long periods in the rubber plantations, their risk of exposure is increased greatly compared to those who temporarily enter natural forests or remain in the village. This study highlights the necessity of broadening mosquito control to include rubber plantations. PMID:28742854

Re-imagining malaria: heterogeneity of human and mosquito behaviour in relation to residual malaria transmission in Cambodia.

PubMed

Gryseels, Charlotte; Durnez, Lies; Gerrets, René; Uk, Sambunny; Suon, Sokha; Set, Srun; Phoeuk, Pisen; Sluydts, Vincent; Heng, Somony; Sochantha, Tho; Coosemans, Marc; Peeters Grietens, Koen

2015-04-24

In certain regions in Southeast Asia, where malaria is reduced to forested regions populated by ethnic minorities dependent on slash-and-burn agriculture, malaria vector populations have developed a propensity to feed early and outdoors, limiting the effectiveness of long-lasting insecticide-treated nets (LLIN) and indoor residual spraying (IRS). The interplay between heterogeneous human, as well as mosquito behaviour, radically challenges malaria control in such residual transmission contexts. This study examines human behavioural patterns in relation to the vector behaviour. The anthropological research used a sequential mixed-methods study design in which quantitative survey research methods were used to complement findings from qualitative ethnographic research. The qualitative research existed of in-depth interviews and participant observation. For the entomological research, indoor and outdoor human landing collections were performed. All research was conducted in selected villages in Ratanakiri province, Cambodia. Variability in human behaviour resulted in variable exposure to outdoor and early biting vectors: (i) indigenous people were found to commute between farms in the forest, where malaria exposure is higher, and village homes; (ii) the indoor/outdoor biting distinction was less clear in forest housing often completely or partly open to the outside; (iii) reported sleeping times varied according to the context of economic activities, impacting on the proportion of infections that could be accounted for by early or nighttime biting; (iv) protection by LLINs may not be as high as self-reported survey data indicate, as observations showed around 40% (non-treated) market net use while (v) unprotected evening resting and deep forest activities impacted further on the suboptimal use of LLINs. The heterogeneity of human behaviour and the variation of vector densities and biting behaviours may lead to a considerable proportion of exposure occurring during times that people are assumed to be protected by the distributed LLINs. Additional efforts in improving LLIN use during times when people are resting in the evening and during the night might still have an impact on further reducing malaria transmission in Cambodia.

Factors that are associated with the risk of acquiring Plasmodium knowlesi malaria in Sabah, Malaysia: a case-control study protocol

PubMed Central

Grigg, M J; William, T; Drakeley, C J; Jelip, J; von Seidlein, L; Barber, B E; Fornace, K M; Anstey, N M; Yeo, T W; Cox, J

2014-01-01

Introduction Plasmodium knowlesi has long been present in Malaysia, and is now an emerging cause of zoonotic human malaria. Cases have been confirmed throughout South-East Asia where the ranges of its natural macaque hosts and Anopheles leucosphyrus group vectors overlap. The majority of cases are from Eastern Malaysia, with increasing total public health notifications despite a concurrent reduction in Plasmodium falciparum and P. vivax malaria. The public health implications are concerning given P. knowlesi has the highest risk of severe and fatal disease of all Plasmodium spp in Malaysia. Current patterns of risk and disease vary based on vector type and competence, with individual exposure risks related to forest and forest-edge activities still poorly defined. Clustering of cases has not yet been systematically evaluated despite reports of peri-domestic transmission and known vector competence for human-to-human transmission. Methods and analysis A population-based case–control study will be conducted over a 2-year period at two adjacent districts in north-west Sabah, Malaysia. Confirmed malaria cases presenting to the district hospital sites meeting relevant inclusion criteria will be requested to enrol. Three community controls matched to the same village as the case will be selected randomly. Study procedures will include blood sampling and administration of household and individual questionnaires to evaluate potential exposure risks associated with acquisition of P. knowlesi malaria. Secondary outcomes will include differences in exposure variables between P. knowlesi and other Plasmodium spp, risk of severe P. knowlesi malaria, and evaluation of P. knowlesi case clustering. Primary analysis will be per protocol, with adjusted ORs for exposure risks between cases and controls calculated using conditional multiple logistic regression models. Ethics This study has been approved by the human research ethics committees of Malaysia, the Menzies School of Health Research, Australia, and the London School of Hygiene and Tropical Medicine, UK. PMID:25149186

Burden of asymptomatic malaria among a tribal population in a forested village of central India: a hidden challenge for malaria control in India.

PubMed

Chourasia, M K; Raghavendra, K; Bhatt, R M; Swain, D K; Valecha, N; Kleinschmidt, I

2017-06-01

Chhattisgarh in India is a malaria-endemic state with seven southern districts that contributes approximately 50-60% of the reported malaria cases in the state every year. The problem is further complicated due to asymptomatic malaria cases which are largely responsible for persistent transmission. This study was undertaken in one of the forested villages of the Keshkal subdistrict in Kondagaon district to ascertain the proportion of the population harbouring subclinical malarial infections. Community-based cross-sectional study. Mass blood surveys were undertaken of the entire population of the village in the post-monsoon seasons of 2013 and 2014. Fingerprick blood smears were prepared from individuals of all ages to detect malaria infections in their blood. Individuals with fever at the time of the survey were tested with rapid diagnostic tests, and parasitaemia in thick blood smears was confirmed by microscopy. Malaria-positive cases were treated with anti-malarials in accordance with the national drug policy. Peripheral blood smears of 134 and 159 individuals, including children, were screened for malaria infection in 2013 and 2014, respectively. Overall, the malaria slide positivity rates were 27.6% and 27.7% in 2013 and 2014, respectively, and the prevalence rates of asymptomatic malaria were 20% and 22.8%. This study showed that, for two consecutive years, the prevalence of asymptomatic malaria infection was significantly higher among children aged ≤14 years (34.4% and 34.1% for 2013 and 2014, respectively) compared with adults (15.2% and 18.2% for 2013 and 2014, respectively; P = 0.023 and 0.04, respectively). The number of asymptomatic malaria cases, especially Plasmodium falciparum, is significant, reinforcing the underlying challenge facing the malaria elimination programme in India. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Biodiversity Can Help Prevent Malaria Outbreaks in Tropical Forests

PubMed Central

Laporta, Gabriel Zorello; de Prado, Paulo Inácio Knegt Lopez; Kraenkel, Roberto André; Coutinho, Renato Mendes; Sallum, Maria Anice Mureb

2013-01-01

Background Plasmodium vivax is a widely distributed, neglected parasite that can cause malaria and death in tropical areas. It is associated with an estimated 80–300 million cases of malaria worldwide. Brazilian tropical rain forests encompass host- and vector-rich communities, in which two hypothetical mechanisms could play a role in the dynamics of malaria transmission. The first mechanism is the dilution effect caused by presence of wild warm-blooded animals, which can act as dead-end hosts to Plasmodium parasites. The second is diffuse mosquito vector competition, in which vector and non-vector mosquito species compete for blood feeding upon a defensive host. Considering that the World Health Organization Malaria Eradication Research Agenda calls for novel strategies to eliminate malaria transmission locally, we used mathematical modeling to assess those two mechanisms in a pristine tropical rain forest, where the primary vector is present but malaria is absent. Methodology/Principal Findings The Ross–Macdonald model and a biodiversity-oriented model were parameterized using newly collected data and data from the literature. The basic reproduction number () estimated employing Ross–Macdonald model indicated that malaria cases occur in the study location. However, no malaria cases have been reported since 1980. In contrast, the biodiversity-oriented model corroborated the absence of malaria transmission. In addition, the diffuse competition mechanism was negatively correlated with the risk of malaria transmission, which suggests a protective effect provided by the forest ecosystem. There is a non-linear, unimodal correlation between the mechanism of dead-end transmission of parasites and the risk of malaria transmission, suggesting a protective effect only under certain circumstances (e.g., a high abundance of wild warm-blooded animals). Conclusions/Significance To achieve biological conservation and to eliminate Plasmodium parasites in human populations, the World Health Organization Malaria Eradication Research Agenda should take biodiversity issues into consideration. PMID:23556023

Studies on malaria and Anopheles balabacensis in Cambodia

PubMed Central

Eyles, Don E.; Wharton, R. H.; Cheong, W. H.; Warren, McWilson

1964-01-01

During the past few years Anopheles balabacensis has come to be recognized as a very important human malaria vector in Thailand and the Indochinese area, but little has been published on its bionomics except from North Borneo. Studies of the feeding habits of A. balabacensis in Cambodia showed it to be predominantly a forest mosquito. It was readily attracted to monkeys in the forest canopy but also readily attacked man on the ground. Very few of this species were attracted to domestic animals. Malaria infections were found more frequently in mosquitos captured in villages, but a significant number were infected from the forest beyond flight range of human habitation. The human population showed a high percentage of persons infected with malaria, Plasmodium falciparum predominating. Cambodian monkeys were found also to be infected with P. cynomolgi. Although none of thirteen monkeys injected with sporozoites from wild-caught mosquitos came down with malaria, it was concluded that A. balabacensis probably was the vector of both human and monkey malaria and that the risk of cross-infection was considerable if monkey malarias infective to man exist in the area. PMID:14122444

Ecology, economics and political will: the vicissitudes of malaria strategies in Asia.

PubMed

Kidson, C; Indaratna, K

1998-06-01

The documented history of malaria in parts of Asia goes back more than 2,000 years, during which the disease has been a major player on the socioeconomic stage in many nation states as they waxed and waned in power and prosperity. On a much shorter time scale, the last half century has seen in microcosm a history of large fluctuations in endemicity and impact of malaria across the spectrum of rice fields and rain forests, mountains and plains that reflect the vast ecological diversity inhabited by this majority aggregation of mankind. That period has seen some of the most dramatic changes in social and economic structure, in population size, density and mobility, and in political structure in history: all have played a part in the changing face of malaria in this extensive region of the world. While the majority of global malaria cases currently reside in Africa, greater numbers inhabited Asia earlier this century before malaria programs savored significant success, and now Asia harbors a global threat in the form of the epicenter of multidrug resistant Plasmodium falciparum which is gradually encompassing the tropical world. The latter reflects directly the vicissitudes of economic change over recent decades, particularly the mobility of populations in search of commerce, trade and personal fortunes, or caught in the misfortunes of physical conflicts. The period from the 1950s to the 1990s has witnessed near "eradication" followed by resurgence of malaria in Sri Lanka, control and resurgence in India, the influence of war and postwar instability on drug resistance in Cambodia, increase in severe and cerebral malaria in Myanmar during prolonged political turmoil, the essential disappearance of the disease from all but forested border areas of Thailand where it remains for the moment intractable, the basic elimination of vivax malaria from many provinces of central China. Both positive and negative experiences have lessons to teach in the debate between eradication and control as alternative strategies. China has for years held high the goal of "basic elimination", eradication by another name, in sensible semi-defiance of WHO dictates. The Chinese experience makes it clear that, given community organization, exhaustive attention to case detection, management and focus elimination, plus the political will at all levels of society, it is possible both to eliminate malaria from large areas of an expansive nation and to implement surveillance necessary to maintain something approaching eradication status in those areas. But China has not succeeded in the international border regions of the tropical south where unfettered population movement confounds the program. Thailand, Malaysia and to an extent Vietnam have also reached essential elimination in their rice field plains by vigorous vertical programs but fall short at their forested borders. Economics is central to the history of the rise and fall of nations, and to the history of disease in the people who constitute nations. The current love affair with free market economics as the main driving force for advance of national wealth puts severe limitations on the essential involvement of communities in malaria management. The task of malaria control or elimination needs to be clearly related to the basic macroeconomic process that preoccupies governments, not cloistered away in the health sector Historically malaria has had a severe, measurable, negative impact on the productivity of nations. Economic models need rehoning with political aplomb and integrating with technical and demographic strategies. Recent decades in Chinese malaria history carry some lessons that may be relevant in this context.

Avian malaria in Hawaiian forest birds: Infection and population impacts across species and elevations

USGS Publications Warehouse

Samuel, Michael D.; Woodworth, Bethany L.; Atkinson, Carter T.; Hart, P. J.; LaPointe, Dennis

2015-01-01

Wildlife diseases can present significant threats to ecological systems and biological diversity, as well as domestic animal and human health. However, determining the dynamics of wildlife diseases and understanding the impact on host populations is a significant challenge. In Hawai‘i, there is ample circumstantial evidence that introduced avian malaria (Plasmodium relictum) has played an important role in the decline and extinction of many native forest birds. However, few studies have attempted to estimate disease transmission and mortality, survival, and individual species impacts in this distinctive ecosystem. We combined multi-state capture-recapture (longitudinal) models with cumulative age-prevalence (cross-sectional) models to evaluate these patterns in Apapane, Hawai‘i Amakihi, and Iiwi in low-, mid-, and high-elevation forests on the island of Hawai‘i based on four longitudinal studies of 3–7 years in length. We found species-specific patterns of malaria prevalence, transmission, and mortality rates that varied among elevations, likely in response to ecological factors that drive mosquito abundance. Malaria infection was highest at low elevations, moderate at mid elevations, and limited in high-elevation forests. Infection rates were highest for Iiwi and Apapane, likely contributing to the absence of these species in low-elevation forests. Adult malaria fatality rates were highest for Iiwi, intermediate for Amakihi at mid and high elevations, and lower for Apapane; low-elevation Amakihi had the lowest malaria fatality, providing strong evidence of malaria tolerance in this low-elevation population. Our study indicates that hatch-year birds may have greater malaria infection and/or fatality rates than adults. Our study also found that mosquitoes prefer feeding on Amakihi rather than Apapane, but Apapane are likely a more important reservoir for malaria transmission to mosquitoes. Our approach, based on host abundance and infection rates, may be an effective alternative to mosquito blood meal analysis for determining vector-host contacts when mosquito densities are low and collection of blood-fed mosquitoes is impractical. Our study supports the hypothesis that avian malaria has been a primary factor influencing the elevational distribution and abundance of these three species, and likely limits other native Hawaiian species that are susceptible to malaria.

Land surface and climate parameters and malaria features in Vietnam

NASA Astrophysics Data System (ADS)

Liou, Y. A.; Anh, N. K.

2017-12-01

Land surface parameters may affect local microclimate, which in turn alters the development of mosquito habitats and transmission risks (soil-vegetation-atmosphere-vector borne diseases). Forest malaria is a chromic issue in Southeast Asian countries, in particular, such as Vietnam (in 1991, approximate 2 million cases and 4,646 deaths were reported (https://sites.path.org)). Vietnam has lowlands, sub-tropical high humidity, and dense forests, resulting in wide-scale distribution and high biting rate of mosquitos in Vietnam, becoming a challenging and out of control scenario, especially in Vietnamese Central Highland region. It is known that Vietnam's economy mainly relies on agriculture and malaria is commonly associated with poverty. There is a strong demand to investigate the relationship between land surface parameters (land cover, soil moisture, land surface temperature, etc.) and climatic variables (precipitation, humidity, evapotranspiration, etc.) in association with malaria distribution. GIS and remote sensing have been proven their powerful potentials in supporting environmental and health studies. The objective of this study aims to analyze physical attributes of land surface and climate parameters and their links with malaria features. The outcomes are expected to illustrate how remotely sensed data has been utilized in geohealth applications, surveillance, and health risk mapping. In addition, a platform with promising possibilities of allowing disease early-warning systems with citizen participation will be proposed.

Men Traveling Away from Home Are More Likely to Bring Malaria into High Altitude Villages, Northwest Ethiopia

PubMed Central

Alemu, Kassahun; Worku, Alemayehu; Berhane, Yemane; Kumie, Abera

2014-01-01

Background Information about malaria risk factors at high altitudes is scanty. Understanding the risk factors that determine the risk of malaria transmission at high altitude villages is important to facilitate implementing sustainable malaria control and prevention programs. Methods An unmatched case control study was conducted among patients seeking treatment at health centers in high altitude areas. Either microscopy or rapid diagnostic tests were used to confirm the presence of plasmodium species. A generalized linear model was used to identify the predictors of malaria transmission in high altitude villages. Results Males (AOR = 3.11, 95%CI: 2.28, 4.23), and those who traveled away from the home in the previous month (AOR = 2.01, 95% CI: 1.56, 2.58) were strongly associated with presence of malaria in high altitude villages. Other significant factors, including agriculture in occupation (AOR = 1.41, 95% CI: 1.05, 1.93), plants used for fencing (AOR = 1.70, 95% CI: 1.18, 2.52) and forests near the house (AOR = 1.60, 95% CI: 1.15, 2.47), were found predictors for malaria in high altitude villages. Conclusion Travel outside of their home was an important risk of malaria infections acquisition. Targeting males who frequently travel to malarious areas can reduce malaria transmission risks in high altitude areas. PMID:24748159

Malaria in the state of Rio de Janeiro, Brazil, an Atlantic Forest area: an assessment using the health surveillance service

PubMed Central

Miguel, Renata Bortolasse; Peiter, Paulo Cesar; de Albuquerque, Hermano; Coura, José Rodrigues; Moza, Patrícia Ganzenmüller; Costa, Anielle de Pina; Brasil, Patricia; Suárez-Mutis, Martha Cecília

2014-01-01

The lethality of malaria in the extra-Amazonian region is more than 70 times higher than in Amazonia itself. Recently, several studies have shown that autochthonous malaria is not a rare event in the Brazilian southeastern states in the Atlantic Forest biome. Information about autochthonous malaria in the state of Rio de Janeiro (RJ) is scarce. This study aims to assess malaria cases reported to the Health Surveillance System of the State of Rio de Janeiro between 2000-2010. An average of 90 cases per year had parasitological malaria confirmation by thick smear. The number of malaria notifications due to Plasmodium falciparum increased over time. Imported cases reported during the period studied were spread among 51% of the municipalities (counties) of the state. Only 35 cases (4.3%) were autochthonous, which represents an average of 3.8 new cases per year. Eleven municipalities reported autochthonous cases; within these, six could be characterised as areas of residual or new foci of malaria from the Atlantic Forest system. The other 28 municipalities could become receptive for transmission reintroduction. Cases occurred during all periods of the year, but 62.9% of cases were in the first semester of each year. Assessing vulnerability and receptivity conditions and vector ecology is imperative to establish the real risk of malaria reintroduction in RJ. PMID:25185004

Spatio-temporal heterogeneity of malaria morbidity in Ghana: Analysis of routine health facility data

PubMed Central

Malm, Keziah; Peprah, Nana Yaw; Silal, Sheetal P.

2018-01-01

Background Malaria incidence is largely influenced by vector abundance. Among the many interconnected factors relating to malaria transmission, weather conditions such as rainfall and temperature are known to create suitable environmental conditions that sustain reproduction and propagation of anopheles mosquitoes and malaria parasites. In Ghana, climatic conditions vary across the country. Understanding the heterogeneity of malaria morbidity using data sourced from a recently setup data repository for routine health facility data could support planning. Methods Monthly aggregated confirmed uncomplicated malaria cases from the District Health Information Management System and average monthly rainfall and temperature records obtained from the Ghana Meteorological Agency from 2008 to 2016 were analysed. Univariate time series models were fitted to the malaria, rainfall and temperature data series. After pre-whitening the morbidity data, cross correlation analyses were performed. Subsequently, transfer function models were developed for the relationship between malaria morbidity and rainfall and temperature. Results Malaria morbidity patterns vary across zones. In the Guinea savannah, morbidity peaks once in the year and twice in both the Transitional forest and Coastal savannah, following similar patterns of rainfall at the zonal level. While the effects of rainfall on malaria morbidity are delayed by a month in the Guinea savannah and Transitional Forest zones those of temperature are delayed by two months in the Transitional forest zone. In the Coastal savannah however, incidence of malaria is significantly associated with two months lead in rainfall and temperature. Conclusion Data captured on the District Health Information Management System has been used to demonstrate heterogeneity in the dynamics of malaria morbidity across the country. Timing of these variations could guide the deployment of interventions such as indoor residual spraying, Seasonal Malaria Chemoprevention or vaccines to optimise effectiveness on zonal basis. PMID:29377908

Spatio-temporal heterogeneity of malaria morbidity in Ghana: Analysis of routine health facility data.

PubMed

Awine, Timothy; Malm, Keziah; Peprah, Nana Yaw; Silal, Sheetal P

2018-01-01

Malaria incidence is largely influenced by vector abundance. Among the many interconnected factors relating to malaria transmission, weather conditions such as rainfall and temperature are known to create suitable environmental conditions that sustain reproduction and propagation of anopheles mosquitoes and malaria parasites. In Ghana, climatic conditions vary across the country. Understanding the heterogeneity of malaria morbidity using data sourced from a recently setup data repository for routine health facility data could support planning. Monthly aggregated confirmed uncomplicated malaria cases from the District Health Information Management System and average monthly rainfall and temperature records obtained from the Ghana Meteorological Agency from 2008 to 2016 were analysed. Univariate time series models were fitted to the malaria, rainfall and temperature data series. After pre-whitening the morbidity data, cross correlation analyses were performed. Subsequently, transfer function models were developed for the relationship between malaria morbidity and rainfall and temperature. Malaria morbidity patterns vary across zones. In the Guinea savannah, morbidity peaks once in the year and twice in both the Transitional forest and Coastal savannah, following similar patterns of rainfall at the zonal level. While the effects of rainfall on malaria morbidity are delayed by a month in the Guinea savannah and Transitional Forest zones those of temperature are delayed by two months in the Transitional forest zone. In the Coastal savannah however, incidence of malaria is significantly associated with two months lead in rainfall and temperature. Data captured on the District Health Information Management System has been used to demonstrate heterogeneity in the dynamics of malaria morbidity across the country. Timing of these variations could guide the deployment of interventions such as indoor residual spraying, Seasonal Malaria Chemoprevention or vaccines to optimise effectiveness on zonal basis.

Deviance and resistance: Malaria elimination in the greater Mekong subregion.

PubMed

Lyttleton, Chris

2016-02-01

Malaria elimination rather than control is increasingly globally endorsed, requiring new approaches wherein success is not measured by timely treatment of presenting cases but eradicating all presence of infection. This shift has gained urgency as resistance to artemisinin-combination therapies spreads in the Greater Mekong Sub-region (GMS) posing a threat to global health security. In the GMS, endemic malaria persists in forested border areas and elimination will require calibrated approaches to remove remaining pockets of residual infection. A new public health strategy called 'positive deviance' is being used to improve health promotion and community outreach in some of these zones. However, outbreaks sparked by alternative understandings of appropriate behaviour expose the unpredictable nature of 'border malaria' and difficulties eradication faces. Using a recent spike in infections allegedly linked to luxury timber trade in Thai borderlands, this article suggests that opportunities for market engagement can cause people to see 'deviance' as a means to material advancement in ways that increase disease vulnerability. A malaria outbreak in Ubon Ratchathani was investigated during two-week field-visit in November 2014 as part of longer project researching border malaria in Thai provinces. Qualitative data were collected in four villages in Ubon's three most-affected districts. Discussions with villagers focused primarily on changing livelihoods, experience with malaria, and rosewood cutting. Informants included ten men and two women who had recently overnighted in the nearby forest. Data from health officials and villagers are used to frame Ubon's rise in malaria transmission within moral and behavioural responses to expanding commodity supply-chains. The article argues that elimination strategies in the GMS must contend with volatile outbreaks among border populations wherein 'infectiousness' and 'resistance' are not simply pathogen characteristics but also behavioural dimensions born of insistent market aspirations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ecological characterisation and infection of Anophelines (Diptera: Culicidae) of the Atlantic Forest in the southeast of Brazil over a 10 year period: has the behaviour of the autochthonous malaria vector changed?

PubMed

Buery, Julyana Cerqueira; Rezende, Helder Ricas; Natal, Licia; Silva, Leonardo Santana da; Menezes, Regiane Maria Tironi de; Fux, Blima; Malafronte, Rosely Dos Santos; Falqueto, Aloisio; Cerutti Junior, Crispim

2018-02-01

BACKGROUND In southeastern Brazil, autochthonous cases of malaria can be found near Atlantic Forest fragments. Because the transmission cycle has not been completely clarified, the behaviour of the possible vectors in those regions must be observed. A study concerning the entomological aspects and natural infection of anophelines (Diptera: Culicidae) captured in the municipalities of the mountainous region of Espírito Santo state was performed in 2004 and 2005. Similarly, between 2014 and 2015, 12 monthly collections were performed at the same area of the study mentioned above. METHODS Center for Disease Control (CDC) light traps with CO2 were set in open areas, at the edge and inside of the forest (canopy and ground), whereas Shannon traps were set on the edge. FINDINGS A total of 1,414 anophelines were collected from 13 species. Anopheles (Kerteszia) cruzii Dyar and Knab remained the most frequently captured species in the CDC traps set in the forest canopy, as well as being the vector with the highest prevalence of Plasmodium vivax/simium infection, according to molecular polymerase chain reaction techniques. CONCLUSIONS P. vivax/simium was found only in abdomens of the mosquitoes of the subgenus Nyssorhynchus, weakening the hypothesis that this subgenus also plays a role in malaria transmission in this specific region.

Malaria transmission in Tripura: Disease distribution & determinants.

PubMed

Dev, Vas; Adak, Tridibes; Singh, Om P; Nanda, Nutan; Baidya, Bimal K

2015-12-01

Malaria is a major public health problem in Tripura and focal disease outbreaks are of frequent occurrence. The state is co-endemic for both Plasmodium falciparum and P. vivax and transmission is perennial and persistent. The present study was aimed to review data on disease distribution to prioritize high-risk districts, and to study seasonal prevalence of disease vectors and their bionomical characteristics to help formulate vector species-specific interventions for malaria control. Data on malaria morbidity in the State were reviewed retrospectively (2008-2012) for understanding disease distribution and transmission dynamics. Cross-sectional mass blood surveys were conducted in malaria endemic villages of South Tripura district to ascertain the prevalence of malaria and proportions of parasite species. Mosquito collections were made in human dwellings of malaria endemic villages aiming at vector incrimination and to study relative abundance, resting and feeding preferences, and their present susceptibility status to DDT. The study showed that malaria was widely prevalent and P. falciparum was the predominant infection (>90%), the remaining were P. vivax cases. The disease distribution, however, was uneven with large concentration of cases in districts of South Tripura and Dhalai coinciding with vast forest cover and tribal populations. Both Anopheles minimus s.s. and An. baimaii were recorded to be prevalent and observed to be highly anthropophagic and susceptible to DDT. Of these, An. minimus was incriminated (sporozoite infection rate 4.92%), and its bionomical characteristics revealed this species to be largely indoor resting and endophagic. For effective control of malaria in the state, it is recommended that diseases surveillance should be robust, and vector control interventions including DDT spray coverage, mass distribution of insecticide-treated nets/ long-lasting insecticidal nets should be intensified prioritizing population groups most at risk to avert impending disease outbreaks and spread of drug-resistant malaria.

Mapping intra-urban malaria risk using high resolution satellite imagery: a case study of Dar es Salaam.

PubMed

Kabaria, Caroline W; Molteni, Fabrizio; Mandike, Renata; Chacky, Frank; Noor, Abdisalan M; Snow, Robert W; Linard, Catherine

2016-07-30

With more than half of Africa's population expected to live in urban settlements by 2030, the burden of malaria among urban populations in Africa continues to rise with an increasing number of people at risk of infection. However, malaria intervention across Africa remains focused on rural, highly endemic communities with far fewer strategic policy directions for the control of malaria in rapidly growing African urban settlements. The complex and heterogeneous nature of urban malaria requires a better understanding of the spatial and temporal patterns of urban malaria risk in order to design effective urban malaria control programs. In this study, we use remotely sensed variables and other environmental covariates to examine the predictability of intra-urban variations of malaria infection risk across the rapidly growing city of Dar es Salaam, Tanzania between 2006 and 2014. High resolution SPOT satellite imagery was used to identify urban environmental factors associated malaria prevalence in Dar es Salaam. Supervised classification with a random forest classifier was used to develop high resolution land cover classes that were combined with malaria parasite prevalence data to identify environmental factors that influence localized heterogeneity of malaria transmission and develop a high resolution predictive malaria risk map of Dar es Salaam. Results indicate that the risk of malaria infection varied across the city. The risk of infection increased away from the city centre with lower parasite prevalence predicted in administrative units in the city centre compared to administrative units in the peri-urban suburbs. The variation in malaria risk within Dar es Salaam was shown to be influenced by varying environmental factors. Higher malaria risks were associated with proximity to dense vegetation, inland water and wet/swampy areas while lower risk of infection was predicted in densely built-up areas. The predictive maps produced can serve as valuable resources for municipal councils aiming to shrink the extents of malaria across cities, target resources for vector control or intensify mosquito and disease surveillance. The semi-automated modelling process developed can be replicated in other urban areas to identify factors that influence heterogeneity in malaria risk patterns and detect vulnerable zones. There is a definite need to expand research into the unique epidemiology of malaria transmission in urban areas for focal elimination and sustained control agendas.

Factors that are associated with the risk of acquiring Plasmodium knowlesi malaria in Sabah, Malaysia: a case-control study protocol.

PubMed

Grigg, M J; William, T; Drakeley, C J; Jelip, J; von Seidlein, L; Barber, B E; Fornace, K M; Anstey, N M; Yeo, T W; Cox, J

2014-08-22

Plasmodium knowlesi has long been present in Malaysia, and is now an emerging cause of zoonotic human malaria. Cases have been confirmed throughout South-East Asia where the ranges of its natural macaque hosts and Anopheles leucosphyrus group vectors overlap. The majority of cases are from Eastern Malaysia, with increasing total public health notifications despite a concurrent reduction in Plasmodium falciparum and P. vivax malaria. The public health implications are concerning given P. knowlesi has the highest risk of severe and fatal disease of all Plasmodium spp in Malaysia. Current patterns of risk and disease vary based on vector type and competence, with individual exposure risks related to forest and forest-edge activities still poorly defined. Clustering of cases has not yet been systematically evaluated despite reports of peri-domestic transmission and known vector competence for human-to-human transmission. A population-based case-control study will be conducted over a 2-year period at two adjacent districts in north-west Sabah, Malaysia. Confirmed malaria cases presenting to the district hospital sites meeting relevant inclusion criteria will be requested to enrol. Three community controls matched to the same village as the case will be selected randomly. Study procedures will include blood sampling and administration of household and individual questionnaires to evaluate potential exposure risks associated with acquisition of P. knowlesi malaria. Secondary outcomes will include differences in exposure variables between P. knowlesi and other Plasmodium spp, risk of severe P. knowlesi malaria, and evaluation of P. knowlesi case clustering. Primary analysis will be per protocol, with adjusted ORs for exposure risks between cases and controls calculated using conditional multiple logistic regression models. This study has been approved by the human research ethics committees of Malaysia, the Menzies School of Health Research, Australia, and the London School of Hygiene and Tropical Medicine, UK. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Novel strategies lead to pre-elimination of malaria in previously high-risk areas in Suriname, South America.

PubMed

Hiwat, Hélène; Hardjopawiro, Loretta S; Takken, Willem; Villegas, Leopoldo

2012-01-09

Suriname was a high malaria risk country before the introduction of a new five-year malaria control program in 2005, the Medical Mission Malaria Programme (MM-MP). Malaria was endemic in the forested interior, where especially the stabile village communities were affected. The interventions of the MM-MP included new strategies for prevention, vector control, case management, behavioral change communication (BCC)/information, education and communication (IEC), and strengthening of the health system (surveillance, monitoring and evaluation and epidemic detection system). After a slow first year with non-satisfying scores for the performance indicators, the MM-MP truly engaged in its intervention activities in 2006 and kept its performance up until the end of 2009. A total of 69,994 long-lasting insecticide-treated nets were distributed and more than 15,000 nets re-impregnated. In high-risk areas, this was complemented with residual spraying of insecticides. Over 10,000 people were screened with active case detection in outbreak and high-risk areas. Additional notification points were established and the national health system was strengthened. In the current paper, the MM-MP is evaluated both on account of the targets established within the programme and on account of its impact on the malaria situation in Suriname. Malaria vector populations, monitored in sentinel sites, collapsed after 2006 and concurrently the number of national malaria cases decreased from 8,618 in 2005 to 1,509 in 2009. Malaria transmission risk shifted from the stabile village communities to the mobile gold mining communities, especially those along the French Guiana border. The novel strategies for malaria control introduced in Suriname within the MM-MP have led to a significant decrease in the national malaria burden. The challenge is to further reduce malaria using the available strategies as appropriate in the affected areas and populations. Elimination of malaria in the country will require a thorough understanding of transmission dynamics and a dedicated investment in key effective interventions.

Community-randomized trial of lambdacyhalothrin-treated hammock nets for malaria control in Yanomami communities in the Amazon region of Venezuela.

PubMed

Magris, M; Rubio-Palis, Y; Alexander, N; Ruiz, B; Galván, N; Frias, D; Blanco, M; Lines, J

2007-03-01

We conducted a community-randomized controlled trial in an area of moderate malaria transmission in the Amazon region, southern Venezuela, home of the Yanomami indigenous ethnic group. The aim was to compare the malaria incidence rate in villages with lambdacyhalothrin-treated hammock nets (ITHN) or with placebo-treated hammock nets (PTHN). In both arms of the study, intensive surveillance for early case detection was maintained and prompt malaria treatment was administered. Baseline data were collected before the intervention and a population of around 924 Yanomami was followed for 2 years. Despite the recent introduction of nets in the Yanomami villages and the adverse natural conditions in the area, the nets were accepted enthusiastically by the study population, used conscientiously and looked after carefully. The malaria incidence rate per thousand person-years at risk was 114.6 in the IHTN group and 186.8 in the PTHN group. The adjusted rate ratios indicated that ITHN prevent 56% [IRR: 0.44, 95% confidence interval (CI): 52-59%] of new malaria cases. ITHN reduced the prevalence of parasitaemia by 83% [relative risks (RR): 0.17, 95% CI: 47-100%], according to a cross-sectional survey carried out during the high transmission season. The prevalence of splenomegaly and anaemia was too low to detect any possible reduction as a result of ITHN. The main conclusion of the present study is that ITHN can reduce malaria incidence in the area and it is the most feasible method for malaria control in a forested area where indigenous villages are scattered over a large territory. This is the first community-level epidemiological trial to show that ITHN are highly effective against malaria transmitted by Anopheles darlingi.

Socioeconomic and demographic characterization of an endemic malaria region in Brazil by multiple correspondence analysis.

PubMed

Lana, Raquel M; Riback, Thais I S; Lima, Tiago F M; da Silva-Nunes, Mônica; Cruz, Oswaldo G; Oliveira, Francisco G S; Moresco, Gilberto G; Honório, Nildimar A; Codeço, Cláudia T

2017-10-02

In the process of geographical retraction of malaria, some important endemicity pockets remain. Here, we report results from a study developed to obtain detailed community data from an important malaria hotspot in Latin America (Alto Juruá, Acre, Brazil), to investigate the association of malaria with socioeconomic, demographic and living conditions. A household survey was conducted in 40 localities (n = 520) of Mâncio Lima and Rodrigues Alves municipalities, Acre state. Information on previous malaria, schooling, age, gender, income, occupation, household structure, habits and behaviors related to malaria exposure was collected. Multiple correspondence analysis (MCA) was applied to characterize similarities between households and identify gradients. The association of these gradients with malaria was assessed using regression. The first three dimensions of MCA accounted for almost 50% of the variability between households. The first dimension defined an urban/rurality gradient, where urbanization was associated with the presence of roads, basic services as garbage collection, water treatment, power grid energy, and less contact with the forest. There is a significant association between this axis and the probability of malaria at the household level, OR = 1.92 (1.23-3.02). The second dimension described a gradient from rural settlements in agricultural areas to those in forested areas. Access via dirt road or river, access to electricity power-grid services and aquaculture were important variables. Malaria was at lower risk at the forested area, OR = 0.55 (1.23-1.12). The third axis detected intraurban differences and did not correlate with malaria. Living conditions in the study area are strongly geographically structured. Although malaria is found throughout all the landscapes, household traits can explain part of the variation found in the odds of having malaria. It is expected these results stimulate further discussions on modelling approaches targeting a more systemic and multi-level view of malaria dynamics.

Ecology and conservation biology of avian malaria.

PubMed

Lapointe, Dennis A; Atkinson, Carter T; Samuel, Michael D

2012-02-01

Avian malaria is a worldwide mosquito-borne disease caused by Plasmodium parasites. These parasites occur in many avian species but primarily affect passerine birds that have not evolved with the parasite. Host pathogenicity, fitness, and population impacts are poorly understood. In contrast to continental species, introduced avian malaria poses a substantial threat to naive birds on Hawaii, the Galapagos, and other archipelagoes. In Hawaii, transmission is maintained by susceptible native birds, competence and abundance of mosquitoes, and a disease reservoir of chronically infected native birds. Although vector habitat and avian communities determine the geographic distribution of disease, climate drives transmission patterns ranging from continuous high infection in warm lowland forests, seasonal infection in midelevation forests, and disease-free refugia in cool high-elevation forests. Global warming is expected to increase the occurrence, distribution, and intensity of avian malaria across this elevational gradient and threaten high-elevation refugia, which is the key to survival of many susceptible Hawaiian birds. Increased temperatures may have already increased global avian malaria prevalence and contributed to an emergence of disease in New Zealand. © 2012 New York Academy of Sciences.

Prevalence of malaria parasites (Plasmodium floridense and Plasmodium azurophilum) infecting a Puerto Rican lizard (Anolis gundlachi): a nine-year study.

PubMed

Schall, J J; Pearson, A R; Perkins, S L

2000-06-01

The prevalence of malaria parasites was studied in the lizard Anolis gundlachi over a 9-yr period at a site in the wet evergreen forest of eastern Puerto Rico. Three forms of the parasite infected the lizards; these were Plasmodium floridense, Plasmodium azurophilum in erythrocytes, and P. azurophilum in white blood cells. Overall prevalence of infection for 8 samples during the study period was significantly higher for males than females (32% of 3,296 males and 22% of 1,439 females). During the study, the site experienced substantial climatic and physical disturbance including rising temperature, droughts, and hurricanes that severely damaged the forest. Parasite prevalence in the first sample, 8 mo after the massive hurricane Hugo, was slightly, though significantly, lower than for subsequent samples. However, overall prevalence was stable during the 9-yr period. The results show malaria prevalence is more constant at the site than found for 2 studies in temperate forests, and that the Puerto Rico system may be an example of the stable, endemic malaria described by standard models for human malaria epidemiology.

Ecology and conservation biology of avian malaria

USGS Publications Warehouse

LaPointe, Dennis A.; Atkinson, Carter T.; Samuel, Michael D.

2012-01-01

Avian malaria is a worldwide mosquito-borne disease caused by Plasmodium parasites. These parasites occur in many avian species but primarily affect passerine birds that have not evolved with the parasite. Host pathogenicity, fitness, and population impacts are poorly understood. In contrast to continental species, introduced avian malaria poses a substantial threat to naive birds on Hawaii, the Galapagos, and other archipelagoes. In Hawaii, transmission is maintained by susceptible native birds, competence and abundance of mosquitoes, and a disease reservoir of chronically infected native birds. Although vector habitat and avian communities determine the geographic distribution of disease, climate drives transmission patterns ranging from continuous high infection in warm lowland forests, seasonal infection in midelevation forests, and disease-free refugia in cool high-elevation forests. Global warming is expected to increase the occurrence, distribution, and intensity of avian malaria across this elevational gradient and threaten high-elevation refugia, which is the key to survival of many susceptible Hawaiian birds. Increased temperatures may have already increased global avian malaria prevalence and contributed to an emergence of disease in New Zealand.

Small-scale land-use variability affects Anopheles spp. distribution and concomitant Plasmodium infection in humans and mosquito vectors in southeastern Madagascar.

PubMed

Zohdy, Sarah; Derfus, Kristin; Headrick, Emily G; Andrianjafy, Mbolatiana Tovo; Wright, Patricia C; Gillespie, Thomas R

2016-02-24

Deforestation and land-use change have the potential to alter human exposure to malaria. A large percentage of Madagascar's original forest cover has been lost to slash-and-burn agriculture, and malaria is one of the top causes of mortality on the island. In this study, the influence of land-use on the distribution of Plasmodium vectors and concomitant Plasmodium infection in humans and mosquito vectors was examined in the southeastern rainforests of Madagascar. From June to August 2013, health assessments were conducted on individuals living in sixty randomly selected households in six villages bordering Ranomafana National Park. Humans were screened for malaria using species-specific rapid diagnostic tests (RDTs), and surveyed about insecticide-treated bed net (ITN) usage. Concurrently, mosquitoes were captured in villages and associated forest and agricultural sites. All captured female Anopheline mosquitoes were screened for Plasmodium spp. using a circumsporozoite enzyme-linked immunosorbent assay (csELISA). Anopheles spp. dominated the mosquito communities of agricultural and village land-use sites, accounting for 41.4 and 31.4 % of mosquitoes captured respectively, whereas Anopheles spp. accounted for only 1.6 % of mosquitoes captured from forest sites. Interestingly, most Anopheles spp. (67.7 %) were captured in agricultural sites in close proximity to animal pens, and 90.8 % of Anopheles mosquitoes captured in agricultural sites were known vectors of malaria. Three Anopheline mosquitoes (0.7 %) were positive for malaria (Plasmodium vivax-210) and all positive mosquitoes were collected from agricultural or village land-use sites. Ten humans (3.7 %) tested were positive for P. falciparum, and 23.3 % of those surveyed reported never sleeping under ITNs. This study presents the first report of malaria surveillance in humans and the environment in southeastern Madagascar. These findings suggest that even during the winter, malaria species are present in both humans and mosquitoes; with P. falciparum found in humans, and evidence of P. vivax-210 in mosquito vectors. The presence of P. vivax in resident vectors, but not humans may relate to the high incidence of humans lacking the Duffy protein. The majority of mosquito vectors were found in agricultural land-use sites, in particular near livestock pens. These findings have the potential to inform and improve targeted malaria control and prevention strategies in the region.

Malaria infection and life-style factors among hilltribes along the Thai-Myanmar border area, northern Thailand.

PubMed

Pichainarong, Natchaporn; Chaveepojnkamjorn, Wisit

2004-12-01

A cross sectional study was conducted between January, 2001 and June, 2002 to determine the life-style factors associated with malaria infection among hilltribes in the Chiang Rai Province, Mae Fah Luang district located along the Thai-Myanmar border, northern Thailand. The data collected were a thick blood film examination and a face-to-face interview using a local language interviewer at a mobile clinic or a home visit. The chi-square test, odds ratio, 95% confidence interval and multiple logistic regression were used as data analysis. P. vivax (61.3%) was detected more than P falciparum (38.2%). Parasitic infection was seen in 45.8% of a total of 417 blood examinations. The study area was in a valley covered with forests and small streams, which was ideal for a malaria epidemic. The communities were distributed along different ethnic groups. There were 12 ethnic groups, dominated by the Muser, Eko, and Akha tribes (60-70%). The risk factors included living or working in the forest, accompanying their family during movement through the forest, age < or =14 years (40.9%), poor knowledge of how to protect against malaria (75-80%), and unavailability of protection against malaria via long sleeved clothes, topical repellents, and insecticide treated nets (use and carry), which resulted in an increased exposure to malaria and risk for malaria infection.

Spatial and temporal distribution of falciparum malaria in China

PubMed Central

Lin, Hualiang; Lu, Liang; Tian, Linwei; Zhou, Shuisen; Wu, Haixia; Bi, Yan; Ho, Suzanne C; Liu, Qiyong

2009-01-01

Background Falciparum malaria is the most deadly among the four main types of human malaria. Although great success has been achieved since the launch of the National Malaria Control Programme in 1955, malaria remains a serious public health problem in China. This paper aimed to analyse the geographic distribution, demographic patterns and time trends of falciparum malaria in China. Methods The annual numbers of falciparum malaria cases during 1992–2003 and the individual case reports of each clinical falciparum malaria during 2004–2005 were extracted from communicable disease information systems in China Center for Diseases Control and Prevention. The annual number of cases and the annual incidence were mapped by matching them to corresponding province- and county-level administrative units in a geographic information system. The distribution of falciparum malaria by age, gender and origin of infection was analysed. Time-series analysis was conducted to investigate the relationship between the falciparum malaria in the endemic provinces and the imported falciparum malaria in non-endemic provinces. Results Falciparum malaria was endemic in two provinces of China during 2004–05. Imported malaria was reported in 26 non-endemic provinces. Annual incidence of falciparum malaria was mapped at county level in the two endemic provinces of China: Yunnan and Hainan. The sex ratio (male vs. female) for the number of cases in Yunnan was 1.6 in the children of 0–15 years and it reached 5.7 in the adults over 15 years of age. The number of malaria cases in Yunnan was positively correlated with the imported malaria of concurrent months in the non-endemic provinces. Conclusion The endemic area of falciparum malaria in China has remained restricted to two provinces, Yunnan and Hainan. Stable transmission occurs in the bordering region of Yunnan and the hilly-forested south of Hainan. The age and gender distribution in the endemic area is characterized by the predominance of adult men cases. Imported falciparum malaria in the non-endemic area of China, affected mainly by the malaria transmission in Yunnan, has increased both spatially and temporally. Specific intervention measures targeted at the mobile population groups are warranted. PMID:19523209

Spatial Correlations of Malaria Incidence Hotspots with Environmental Factors in Assam, North East India

NASA Astrophysics Data System (ADS)

Handique, Bijoy K.; Khan, Siraj A.; Dutta, Prafulla; Nath, Manash J.; Qadir, Abdul; Raju, P. L. N.

2016-06-01

Malaria is endemic and a major public health problem in north east (NE) region of India and contributes about 8-12 % of India's malaria positives cases. Historical morbidity pattern of malaria in terms of API (Annual Parasite Incidence) in the state of Assam has been used for delineating the malaria incidence hotspots at health sub centre (HSC) level. Strong spatial autocorrelation (p < 0.01) among the HSCs have been observed in terms of API (Annual Parasite Incidence). Malaria incidence hot spots in the state could be identified based on General G statistics and tested for statistical significance. Spatial correlation of malaria incidence hotspots with physiographic and climatic parameters across 6 agro-climatic zones of the state reveals the types of land cover pattern and the range of elevation contributing to the malaria outbreaks. Analysis shows that villages under malaria hotspots are having more agricultural land, evergreen/semi-evergreen forests with abundant waterbodies. Statistical and spatial analyses of malaria incidence showed a significant positive correlation with malaria incidence hotspots and the elevation (p < 0.05) with villages under malaria hotspots are having average elevation ranging between 17 to 240 MSL. This conforms to the characteristics of two dominant mosquito species in the state Anopheles minimus and An. baimai that prefers the habitat of slow flowing streams in the foot hills and in forest ecosystems respectively.

Effects of Microclimate Condition Changes Due to Land Use and Land Cover Changes on the Survivorship of Malaria Vectors in China-Myanmar Border Region.

PubMed

Zhong, Daibin; Wang, Xiaoming; Xu, Tielong; Zhou, Guofa; Wang, Ying; Lee, Ming-Chieh; Hartsel, Joshua A; Cui, Liwang; Zheng, Bin; Yan, Guiyun

2016-01-01

In the past decade, developing countries have been experiencing rapid land use and land cover changes, including deforestation and cultivation of previously forested land. However, little is known about the impact of deforestation and land-use changes on the life history of malaria vectors and their effects on malaria transmission. This study examined the effects of deforestation and crop cultivation on the adult survivorship of major malaria mosquitoes, Anopheles sinensis and An. minimus in the China-Myanmar border region. We examined three conditions: indoor, forested, and banana plantation. Mean survival time of An. sinensis in banana plantation environment was significantly longer than those in forested environment, and mosquitoes exhibited the longest longevity in the indoor environment. This pattern held for both males and females, and also for An. minimus. To further test the effect of temperature on mosquito survival, we used two study sites with different elevation and ambient temperatures. Significantly higher survivorship of both species was found in sites with lower elevation and higher ambient temperature. Increased vector survival in the deforested area could have an important impact on malaria transmission in Southeast Asia. Understanding how deforestation impacts vector survivorship can help combat malaria transmission.

Spatial analysis of land cover determinants of malaria incidence in the Ashanti Region, Ghana.

PubMed

Krefis, Anne Caroline; Schwarz, Norbert Georg; Nkrumah, Bernard; Acquah, Samuel; Loag, Wibke; Oldeland, Jens; Sarpong, Nimako; Adu-Sarkodie, Yaw; Ranft, Ulrich; May, Jürgen

2011-03-23

Malaria belongs to the infectious diseases with the highest morbidity and mortality worldwide. As a vector-borne disease malaria distribution is strongly influenced by environmental factors. The aim of this study was to investigate the association between malaria risk and different land cover classes by using high-resolution multispectral Ikonos images and Poisson regression analyses. The association of malaria incidence with land cover around 12 villages in the Ashanti Region, Ghana, was assessed in 1,988 children <15 years of age. The median malaria incidence was 85.7 per 1,000 inhabitants and year (range 28.4-272.7). Swampy areas and banana/plantain production in the proximity of villages were strong predictors of a high malaria incidence. An increase of 10% of swampy area coverage in the 2 km radius around a village led to a 43% higher incidence (relative risk [RR] = 1.43, p<0.001). Each 10% increase of area with banana/plantain production around a village tripled the risk for malaria (RR = 3.25, p<0.001). An increase in forested area of 10% was associated with a 47% decrease of malaria incidence (RR = 0.53, p = 0.029). Distinct cultivation in the proximity of homesteads was associated with childhood malaria in a rural area in Ghana. The analyses demonstrate the usefulness of satellite images for the prediction of malaria endemicity. Thus, planning and monitoring of malaria control measures should be assisted by models based on geographic information systems.

Malaria elimination in Lao PDR: the challenges associated with population mobility.

PubMed

Kounnavong, Sengchanh; Gopinath, Deyer; Hongvanthong, Bouasy; Khamkong, Chanthalone; Sichanthongthip, Odai

2017-04-25

Although the Lao People's Democratic Republic (Lao PDR) is comparatively small landlocked country with patterns of both in- and out-migration, its human migration situation has been poorly studied. This is despite all of the country's 18 provinces sharing both official and unofficial border checkpoints with neighboring countries. Economic reforms in the last decade have seen a gradual increase in the promotion of foreign investment, and main towns and transportation networks have been expanding thus offering new opportunities for livelihoods and economic activities.In the last decade, there has also been a significant reduction of reported malaria cases in Lao PDR and while this is an important prerequisite for eliminating malaria in the country, malaria outbreaks reported in the last four years suggest that population mobility, particularly in the south, is an important factor challenging current control efforts.Bolder investment in social sector spending should be geared towards improving health service provision and utilization, ensuring equitable access to primary health care (including malaria) through efforts to achieve universal health coverage targets. This should be extended to populations that are mobile and migrants. The local government plays a critical role in supporting policy and enforcement issues related to private sector project development in the provinces. Cross-border initiatives with neighboring countries, especially in terms of data sharing, surveillance, and response, is essential. Mechanisms to engage the private sector, especially the informal private sector, needs to be explored within the context of existing regulations and laws. Existing and new interventions for outdoor transmission of malaria, especially in forest settings, for high-risk groups including short- and long-term forest workers and their families, mobile and migrant populations, as well as the military must be combined into integrated packages with innovative delivery mechanisms through social marketing approaches. This should happen at multiple points in the mobility pathway and involve the private sector rather than being fully reliant on the national malaria vertical programThis article based on the review of existing literature from abstracts and full texts, includes published, peer-reviewed English language literature sourced through PubMed and grey literature sources through Google and Google Scholar. The review included also case reports, sector reports, conference proceedings, research reports, epidemiology studies, qualitative studies, and census reports in both Lao and English languages. The authors used the search terms: malaria and mobile populations, malaria control program and elimination, health system performance, malaria outbreak, Lao PDR; and included articles published until June 2015.

Opportunities and obstacles to the elimination of malaria from Peninsular Malaysia: knowledge, attitudes and practices on malaria among aboriginal and rural communities

PubMed Central

2010-01-01

Background Despite continuous efforts by the government and private sectors, malaria is still a public health problem in rural Peninsular Malaysia. This study investigated household knowledge, attitude and practices (KAP) regarding malaria in two malaria endemic communities, forest-aboriginal and rural communities, in the Lipis district of Pahang state, Malaysia. Methods A descriptive cross-sectional study with a semi-structured questionnaire was carried out among 100 and 123 households from forest-aboriginal and rural areas, respectively. Results Knowledge about malaria and its transmission is significantly higher among the rural participants than the aborigines (86.2% vs 76%, p < 0.01). However, use of medicinal plants and beliefs in witchcraft and sorcery in treating febrile diseases were significantly higher among the aboriginal population (p < 0.01). There were no significant differences between the two communities in terms of the knowledge about malaria symptoms, attitudes towards its severity and practices in preventive measures against malaria by using mosquito bed nets. However, the knowledge and practice of different preventive measures to combat malaria, such as insecticide and the elimination of breeding areas, was significantly higher among the rural population than the aborigines (p < 0.001). Conclusions Both communities were aware of malaria as a disease, but knowledge, attitudes and practices were inadequate. Providing efficient health education to people residing in malaria endemic areas would improve their understanding about malaria prevention in order to bring about the elimination of malaria from the country. PMID:20497543

Ecological covariates based predictive model of malaria risk in the state of Chhattisgarh, India.

PubMed

Kumar, Rajesh; Dash, Chinmaya; Rani, Khushbu

2017-09-01

Malaria being an endemic disease in the state of Chhattisgarh and ecologically dependent mosquito-borne disease, the study is intended to identify the ecological covariates of malaria risk in districts of the state and to build a suitable predictive model based on those predictors which could assist developing a weather based early warning system. This secondary data based analysis used one month lagged district level malaria positive cases as response variable and ecological covariates as independent variables which were tested with fixed effect panelled negative binomial regression models. Interactions among the covariates were explored using two way factorial interaction in the model. Although malaria risk in the state possesses perennial characteristics, higher parasitic incidence was observed during the rainy and winter seasons. The univariate analysis indicated that the malaria incidence risk was statistically significant associated with rainfall, maximum humidity, minimum temperature, wind speed, and forest cover ( p  < 0.05). The efficient predictive model include the forest cover [IRR-1.033 (1.024-1.042)], maximum humidity [IRR-1.016 (1.013-1.018)], and two-way factorial interactions between district specific averaged monthly minimum temperature and monthly minimum temperature, monthly minimum temperature was statistically significant [IRR-1.44 (1.231-1.695)] whereas the interaction term has a protective effect [IRR-0.982 (0.974-0.990)] against malaria infections. Forest cover, maximum humidity, minimum temperature and wind speed emerged as potential covariates to be used in predictive models for modelling the malaria risk in the state which could be efficiently used for early warning systems in the state.

Communications: Mosquito Habitats, Land Use, and Malaria Risk in Belize from Satellite Imagery

NASA Technical Reports Server (NTRS)

Pope, Kevin; Masuoka, Penny; Rejmankova, Eliska; Grieco, John; Johnson, Sarah; Roberts, Donald

2004-01-01

Satellite imagery of northern Belize is used to examine the distribution of land use and breeding habitats of the malaria vector the Anopheles mosquito. A land cover classification based on multispectral SPOT and multitemporal Radarsat images identified eleven land cover classes, including agricultural, forest, and marsh types. Two of the land cover types, Typha domingensis marsh and flooded forest, are Anopheles vestitipennis larval habitats, and one, Eleocharis spp. marsh, is the larval habitat for Anopheles albimanus. Geographic Information Systems (GIS) analyses of land cover demonstrate that the amount of Typha domingensis in a marsh is positively correlated with the amount of agricultural land in the adjacent upland, and negatively correlated with the amount of adjacent forest. This finding is consistent with the hypothesis that nutrient (phosphorus) runoff from agricultural lands is causing an expansion of Typha domingensis in northern Belize. Thus, land use induced expansion of Anopheles vestitipennis larval habitat is potentially increasing malaria risk in Belize, and in other regions where Anopheles vestitipennis is a major malaria vector.

Does Forest Loss Increase Human Disease? Evidence from Nigeria.

PubMed

Berazneva, Julia; Byker, Tanya S.

2017-05-01

It is estimated that about one quarter of the global disease burden in terms of healthy life years lost and about one quarter of all premature deaths can be attributed to modifiable environmental factors (Pruss-Ustun and Corvalan 2006). Three infectious diseases--diarrhea, respiratory infections, and malaria--account for the largest absolute burden in developing countries with children facing the greatest impacts. There is a growing body of evidence demonstrating the health burden of air and water pollution, as well as important productivity and income effects (see, for example, reviews of the literature in Pattanayak and Pfaff 2009 and Greenstone and Jack 2016). Studies that focus on the impacts of natural resource degradation are fewer. Notably, Garg (2016) provides the first causal estimates of the impact of sustained forest cover on reduced malarial incidence in Indonesia, demonstrating a large and previously understudied cost of forest cover loss. In this paper, we extend this new literature on the health impacts of environmental degradation by estimating the causal impact of forest loss on infectious disease incidence in young children using temporal and spatial variation in the last decade in Nigeria. Our estimation strategy involves geolinking a new high-resolution dataset of global forest change to child-level health data from the Nigeria Demographic and Health Surveys from 2008 and 2013. We find that forest loss significantly increases the incidence of malaria, though it does not affect the incidence of diarrhea and respiratory diseases. The impact of forest loss on malaria is large (one standard deviation of forest loss increases malaria incidence by around 4.5 percent in children under five) and the dynamic pattern of the impact suggests a temporary ecological disturbance consistent with findings in Garg (2016) and the tropical medicine literature.

Partial mitochondrial DNA sequences suggest the existence of a cryptic species within the Leucosphyrus group of the genus Anopheles (Diptera: Culicidae), forest malaria vectors, in northern Vietnam.

PubMed

Takano, Kohei Takenaka; Nguyen, Ngoc Thi Hong; Nguyen, Binh Thi Huong; Sunahara, Toshihiko; Yasunami, Michio; Nguyen, Manh Duc; Takagi, Masahiro

2010-04-30

During the last decade, Southeast Asian countries have been very successful in reducing the burden of malaria. However, malaria remains endemic in these countries, especially in remote and forested areas. The Leucosphyrus group of the genus Anopheles harbors the most important malaria vectors in forested areas of Southeast Asia. In Vietnam, previous molecular studies have resulted in the identification of only Anopheles dirus sensu stricto (previously known as An. dirus species A) among the Leucosphyrus group members. However, Vietnamese entomologists have recognized that mosquitoes belonging to the Leucosphyrus group in northern Vietnam exhibit morphological characteristics similar to those of Anopheles takasagoensis, which has been reported only from Taiwan. Here, we aimed to confirm the genetic and morphological identities of the members of the Leucosphyrus group in Vietnam. In the molecular phylogenetic trees reconstructed using partial COI and ND6 mitochondrial gene sequences, samples collected from southern and central Vietnam clustered together with GenBank sequences of An. dirus that were obtained from Thailand. However, samples from northern Vietnam formed a distinct clade separated from both An. dirus and An. takasagoensis by other valid species. The results suggest the existence of a cryptic species in northern Vietnam that is morphologically similar to, but phylogenetically distant from both An. dirus and An. takasagoensis. We have tentatively designated this possible cryptic species as Anopheles aff. takasagoensis for convenience, until a valid name is assigned. However, it is difficult to distinguish the species solely on the basis of morphological characteristics. Further studies on such as karyotypes and polytene chromosome banding patterns are necessary to confirm whether An. aff. takasagoensis is a valid species. Moreover, studies on (1) the geographic distribution, which is potentially spreading along the Vietnam, China, Laos, and Myanmar borders; (2) morphological and ecological characteristics; and (3) vectorial capacity of this newly identified cryptic species of An. dirus, which is one of the most important malaria vectors in the mainland of Southeast Asia, are necessary for planning efficient malaria vector control programs in this region.

Positive deviance as a novel tool in malaria control and elimination: methodology, qualitative assessment and future potential.

PubMed

Shafique, Muhammad; Edwards, Hannah M; De Beyl, Celine Zegers; Thavrin, Bou Kheng; Min, Myo; Roca-Feltrer, Arantxa

2016-02-16

Positive deviance (PD) is an asset-based, community-driven approach to behaviour change that has successfully been applied to address many health and social problems. It is yet to have been assessed for malaria control but may represent a promising tool for malaria elimination given its suitability in targeting small and remote population groups, apparent sustainability and ability to instil a high amount of community mobilisation. Here, the PD methodology as applied to malaria is explained, with focus upon and qualitative assessment of a proof of concept study in Cambodia. Three villages in Battambang, northwestern Cambodia were selected for the intervention, with an estimated population of 5036 including both residents and migrant workers. In August 2010, field teams conducted a 1 week PD process to sensitise and mobilise the community, establish normative behaviours in relation to malaria control and prevention, identify positive deviant behaviours from within the community, and identify PD volunteers. Until March 2011, PD volunteers were supported by field teams via monthly meetings to conduct activities in their respective communities to increase practice of PD behaviours. In February 2012, 1 year following the end of external support, evaluative interviews were conducted with community members to qualitatively assess community acceptance and interpretation of the PD intervention, perceived behaviour changes, and perceived positive outcomes. Qualitative data from focus group discussions and in-depth interviews showed that the PD approach was well-accepted into the communities and created a strong sense of community empowerment. Positive behaviour change was linked to the PD intervention, including greater usage of nets by forest goers, and use of public health facilities for malaria diagnosis and treatment. One year following the end of external assistance, PD volunteers were still conducting activities in their respective communities. PD offers a promising tool in malaria control and elimination settings. Work is ongoing to quantitatively measure impact of PD on behaviours and malaria transmission and once gathered, national malaria control programmes should be encouraged to look at including PD as part of their national strategies. Feasibility of scale-up, cost-effectiveness, and applicability to other settings and diseases is also currently being explored.

Ecology and diagnosis of introduced avian malaria in Hawaiian forest birds

USGS Publications Warehouse

Atkinson, Carter T.

2005-01-01

Avian malaria is a disease caused by species of protozoan parasites (Plasmodium) that infect birds. Related species commonly infect reptiles, birds and mammals in tropical and temperate regions of the world. Transmitted by mosquitoes, the parasites spend part of their lives in the red blood cells of birds (Figure 1). Avian malaria is common in continental areas, but is absent from the most isolated island archipelagos where mosquitoes do not naturally occur. More than 40 different species of avian Plasmodium have been described, but only one, P. relictum, has been introduced to the Hawaiian Islands. Because they evolved without natural exposure to avian malaria, native Hawaiian honeycreepers are extremely susceptible to this disease. Malaria currently limits the geographic distribution of native species, has population level impacts on survivorship, and is limiting the recovery of threatened and endangered species of forest birds.

A rapid malaria appraisal in the Venezuelan Amazon

PubMed Central

2009-01-01

Background While the federal state of Amazonas bears the highest risk for malaria in Venezuela (2007: 68.4 cases/1000 inhabitants), little comprehensive information about the malaria situation is available from this area. The purpose of this rapid malaria appraisal (RMA) was to provide baseline data about malaria and malaria control in Amazonas. Methods The RMA methodology corresponds to a rapid health impact assessment (HIA) as described in the 1999 Gothenburg consensus. In conjunction with the actors of the malaria surveillance system, all useful data and information, which were accessible within a limited time-frame of five visits to Amazonas, were collected, analysed and interpreted. Results Mortality from malaria is low (< 1 in 105) and slide positivity rates have stayed at the same level for the last two decades (15% ± 6% (SD)). Active case detection accounts for ca. 40% of slides taken. The coverage of the censured population with malaria notification points (NPs) has been achieved in recent years. The main parasite is Plasmodium vivax (84% of cases). The proportion of Plasmodium falciparum is on the decline, possibly driven by the introduction of cost-free artemisinin-based combination therapy (ACT) (1988: 33.4%; 2007: 15.4%). Monitoring and documentation is complete, systematic and consistent, but poorly digitalized. Malaria transmission displayed a visible lag behind rainfall in the capital municipality of Atures, but not in the other municipalities. In comparison to reference microscopy, quality of field microscopy and rapid diagnostic tests (RDTs) is suboptimal (kappa < 0.75). Hot spots of malaria risk were seen in some indigenous ethnic groups. Conflicting strategies in respect of training of community health workers (CHW) and the introduction of new diagnostic tools (RDTs) were observed. Conclusion Malaria control is possible, even in tropical rain forest areas, if the health system is working adequately. Interventions have to be carefully designed and the features of the particular local Latin American context considered. PMID:20003328

Factors influencing the use of topical repellents: implications for the effectiveness of malaria elimination strategies

PubMed Central

Gryseels, Charlotte; Uk, Sambunny; Sluydts, Vincent; Durnez, Lies; Phoeuk, Pisen; Suon, Sokha; Set, Srun; Heng, Somony; Siv, Sovannaroth; Gerrets, René; Tho, Sochantha; Coosemans, Marc; Peeters Grietens, Koen

2015-01-01

In Cambodia, despite an impressive decline in prevalence over the last 10 years, malaria is still a public health problem in some parts of the country. This is partly due to vectors that bite early and outdoors reducing the effectiveness of measures such as Long-Lasting Insecticidal Nets. Repellents have been suggested as an additional control measure in such settings. As part of a cluster-randomized trial on the effectiveness of topical repellents in controlling malaria infections at community level, a mixed-methods study assessed user rates and determinants of use. Repellents were made widely available and Picaridin repellent reduced 97% of mosquito bites. However, despite high acceptability, daily use was observed to be low (8%) and did not correspond to the reported use in surveys (around 70%). The levels of use aimed for by the trial were never reached as the population used it variably across place (forest, farms and villages) and time (seasons), or in alternative applications (spraying on insects, on bed nets, etc.). These findings show the key role of human behavior in the effectiveness of malaria preventive measures, questioning whether malaria in low endemic settings can be reduced substantially by introducing measures without researching and optimizing community involvement strategies. PMID:26574048

Spatio-temporal Dynamics of Wetlands and Malaria in the Ethiopian Highlands Using Multi-sensor Satellite Observations

NASA Astrophysics Data System (ADS)

Midekisa, A. A.; Wimberly, M. C.; Senay, G. B.

2013-12-01

Tropical wetlands provide various beneficial ecosystem services; however, they can also facilitate the transmission of vector-borne diseases. Because wetlands serve as breeding habitats for Anopheles mosquitoes, particularly during the dry season, they are critical eco-hydrologic elements for malaria transmission. The overarching hypothesis of this study is that landscape and regional patterns of wetlands are associated with malaria risk in the Amhara region of Ethiopia. To test this hypothesis, we developed a random forest decision tree model to map seasonal and permanent wetlands in the Amhara region. Wetland training and validation data were acquired from high-resolution imagery in Google Earth and ground surveys. We evaluated the effectiveness of three random forest models using the following sets of predictor variables: (1) topographical indices from 30 m SRTM data, (2) individual reflectance bands and multispectral wetness indices from Landsat TM/ETM+ imagery, and (3) combined spectral and topographic data. The combined model produced the most accurate wetland maps, and we used it to map wetlands across the study area for 2000, 2005, and 2010. We found spatial associations between indicators of malaria risk from historical surveillance data and metrics of wetland cover at a district level. We also quantified seasonal moisture variability among three different land use land cover types (permanent wetland, seasonal wetland, and cropland) using Actual Evapotranspiration (ETa) over a ten year period (2001-2010) derived from MODIS imagery. We found that permanent and seasonal wetlands have peak moisture during the major malaria transmission season (September-November), whereas the permanent wetlands retain moisture and potentially sustain mosquito populations during the low transmission season (December-March). These findings about the spatial and temporal associations of malaria risk and wetlands can help to highlight areas that likely sustain transmission during the dry season and assist public health workers in planning and implementing malaria prevention, control, and elimination strategies for the region.

Habitat suitability of Anopheles vector species and association with human malaria in the Atlantic Forest in south-eastern Brazil.

PubMed

Laporta, Gabriel Zorello; Ramos, Daniel Garkauskas; Ribeiro, Milton Cezar; Sallum, Maria Anice Mureb

2011-08-01

Every year, autochthonous cases of Plasmodium vivax malaria occur in low-endemicity areas of Vale do Ribeira in the south-eastern part of the Atlantic Forest, state of São Paulo, where Anopheles cruzii and Anopheles bellator are considered the primary vectors. However, other species in the subgenus Nyssorhynchus of Anopheles (e.g., Anopheles marajoara) are abundant and may participate in the dynamics of malarial transmission in that region. The objectives of the present study were to assess the spatial distribution of An. cruzii, An. bellator and An. marajoara and to associate the presence of these species with malaria cases in the municipalities of the Vale do Ribeira. Potential habitat suitability modelling was applied to determine both the spatial distribution of An. cruzii, An. bellator and An. marajoara and to establish the density of each species. Poisson regression was utilized to associate malaria cases with estimated vector densities. As a result, An. cruzii was correlated with the forested slopes of the Serra do Mar, An. bellator with the coastal plain and An. marajoara with the deforested areas. Moreover, both An. marajoara and An. cruzii were positively associated with malaria cases. Considering that An. marajoara was demonstrated to be a primary vector of human Plasmodium in the rural areas of the state of Amapá, more attention should be given to the species in the deforested areas of the Atlantic Forest, where it might be a secondary vector.

Seasonal and Spatial Dynamics of the Primary Vector of Plasmodium knowlesi within a Major Transmission Focus in Sabah, Malaysia

PubMed Central

Wong, Meng L.; Chua, Tock H.; Leong, Cherng S.; Khaw, Loke T.; Fornace, Kimberly; Wan-Sulaiman, Wan-Yusoff; William, Timothy; Drakeley, Chris; Ferguson, Heather M.; Vythilingam, Indra

2015-01-01

Background The simian malaria parasite Plasmodium knowlesi is emerging as a public health problem in Southeast Asia, particularly in Malaysian Borneo where it now accounts for the greatest burden of malaria cases and deaths. Control is hindered by limited understanding of the ecology of potential vector species. Methodology/Principal Findings We conducted a one year longitudinal study of P. knowlesi vectors in three sites within an endemic area of Sabah, Malaysia. All mosquitoes were captured using human landing catch. Anopheles mosquitoes were dissected to determine, oocyst, sporozoites and parous rate. Anopheles balabacensis is confirmed as the primary vector of. P. knowlesi (using nested PCR) in Sabah for the first time. Vector densities were significantly higher and more seasonally variable in the village than forest or small scale farming site. However An. balabacensis survival and P. knowlesi infection rates were highest in forest and small scale farm sites. Anopheles balabacensis mostly bites humans outdoors in the early evening between 1800 to 2000hrs. Conclusions/Significance This study indicates transmission is unlikely to be prevented by bednets. This combined with its high vectorial capacity poses a threat to malaria elimination programmes within the region. PMID:26448052

Primate malarias: Diversity, distribution and insights for zoonotic Plasmodium.

PubMed

Faust, Christina; Dobson, Andrew P

2015-12-01

Protozoans within the genus Plasmodium are well-known as the causative agents of malaria in humans. Numerous Plasmodium species parasites also infect a wide range of non-human primate hosts in tropical and sub-tropical regions worldwide. Studying this diversity can provide critical insight into our understanding of human malarias, as several human malaria species are a result of host switches from non-human primates. Current spillover of a monkey malaria, Plasmodium knowlesi , in Southeast Asia highlights the permeability of species barriers in Plasmodium . Also recently, surveys of apes in Africa uncovered a previously undescribed diversity of Plasmodium in chimpanzees and gorillas. Therefore, we carried out a meta-analysis to quantify the global distribution, host range, and diversity of known non-human primate malaria species. We used published records of Plasmodium parasites found in non-human primates to estimate the total diversity of non-human primate malarias globally. We estimate that at least three undescribed primate malaria species exist in sampled primates, and many more likely exist in unstudied species. The diversity of malaria parasites is especially uncertain in regions of low sampling such as Madagascar, and taxonomic groups such as African Old World Monkeys and gibbons. Presence-absence data of malaria across primates enables us to highlight the close association of forested regions and non-human primate malarias. This distribution potentially reflects a long coevolution of primates, forest-adapted mosquitoes, and malaria parasites. The diversity and distribution of primate malaria are an essential prerequisite to understanding the mechanisms and circumstances that allow Plasmodium to jump species barriers, both in the evolution of malaria parasites and current cases of spillover into humans.

Epidemiological and entomological studies of a malaria outbreak among French armed forces deployed at illegal gold mining sites reveal new aspects of the disease's transmission in French Guiana.

PubMed

Pommier de Santi, Vincent; Girod, Romain; Mura, Marie; Dia, Aissata; Briolant, Sébastien; Djossou, Félix; Dusfour, Isabelle; Mendibil, Alexandre; Simon, Fabrice; Deparis, Xavier; Pagès, Frédéric

2016-01-22

In December 2010, a Plasmodium vivax malaria outbreak occurred among French forces involved in a mission to control illegal gold mining in French Guiana. The findings of epidemiological and entomological investigations conducted after this outbreak are presented here. Data related to malaria cases reported to the French armed forces epidemiological surveillance system were collected during the epidemic period from December 2010 to April 2011. A retrospective cohort study was conducted to identify presumed contamination sites. Anopheles mosquitoes were sampled at the identified sites using Mosquito Magnet and CDC light traps. Specimens were identified morphologically and confirmed using molecular methods (sequencing of ITS2 gene and/or barcoding). Anopheles infections with Plasmodium falciparum and P. vivax were tested by both enzyme-linked immunosorbent assay and real-time PCR. Seventy-two P. vivax malaria cases were reported (three were mixed P. falciparum/P. vivax infections), leading to a global attack rate of 26.5% (72/272). Lack of compliance with vector control measures and doxycycline chemoprophylaxis was reported by patients. Two illegal gold mining sites located in remote areas in the primary forest were identified as places of contamination. In all, 595 Anopheles females were caught and 528 specimens were formally identified: 305 Anopheles darlingi, 145 Anopheles nuneztovari s.l., 63 Anopheles marajoara and 15 Anopheles triannulatus s.l. Three An. darlingi were infected by P. falciparum (infection rate: 1.1%) and four An. marajoara by P. vivax (infection rate: 6.4%). The main drivers of the outbreak were the lack of adherence by military personnel to malaria prevention measures and the high level of malaria transmission at illegal gold mining sites. Anopheles marajoara was clearly implicated in malaria transmission for the first time in French Guiana. The high infection rates observed confirm that illegal gold mining sites must be considered as high level malaria transmission areas in the territory. Illegal gold mining activities are challenging the control of malaria in French Guiana. Collaboration with neighbouring countries is necessary to take into account mobile populations such as gold miners. Malaria control strategies in the French armed forces must be adapted to P. vivax malaria and sylvatic Anopheles species.

Additional burden of asymptomatic and sub-patent malaria infections during low transmission season in forested tribal villages in Chhattisgarh, India.

PubMed

Chourasia, Mehul Kumar; Raghavendra, Kamaraju; Bhatt, Rajendra M; Swain, Dipak Kumar; Meshram, Hemraj M; Meshram, Jayant K; Suman, Shrity; Dubey, Vinita; Singh, Gyanendra; Prasad, Kona Madhavinadha; Kleinschmidt, Immo

2017-08-08

The burden of sub-patent malaria is difficult to recognize in low endemic areas due to limitation of diagnostic tools, and techniques. Polymerase chain reaction (PCR), a molecular based technique, is one of the key methods for detection of low parasite density infections. The study objective was to assess the additional burden of asymptomatic and sub-patent malaria infection among tribal populations inhabiting three endemic villages in Keshkal sub-district, Chhattisgarh, India. A cross-sectional survey was conducted in March-June 2016, during the low transmission season, to measure and compare prevalence of malaria infection using three diagnostics: rapid diagnostic test, microscopy and nested-PCR. Out of 437 individuals enrolled in the study, 103 (23.6%) were malaria positive by PCR and/or microscopy of whom 89.3% were Plasmodium falciparum cases, 77.7% were afebrile and 35.9% had sub-patent infections. A substantial number of asymptomatic and sub-patent malaria infections were identified in the survey. Hence, strategies for identifying and reducing the hidden burden of asymptomatic and sub-patent infections should focus on forest rural tribal areas using more sensitive molecular diagnostic methods to curtail malaria transmission.

Risk of daytime transmission of malaria in the French Guiana rain forest.

PubMed

Pommier de Santi, V; Dusfour, I; de Parseval, E; Lespinet, B; Nguyen, C; Gaborit, P; Carinci, R; Hyvert, G; Girod, R; Briolant, S

2017-02-01

Between 2008 and 2014, there were 1070 malaria cases reported in French Guiana among members of the armed forces. Most of the malaria outbreaks investigated were multifactorial and followed missions conducted at illegal gold mining sites. For example, a malaria outbreak occurred in September 2013, three weeks after the deployment of 15 soldiers at Dagobert, which is such a site. The attack rate was 53%, with seven Plasmodium vivax infections and one coinfection with both Plasmodium vivax and Plasmodium falciparum. Two months later, an entomological investigation in the field caught 321 anopheles by the human landing catch method. Among them, 282 were Anopheles darlingi. One specimen was PCR-positive for P. vivax, for an infection rate of 0.4% (1/282). In 15.7% of these cases, the An. darlingi was caught during the day. The existence of daytime biting activity by An. darlingi in the Guianese forest might play a key role in malaria outbreaks among military personnel. This finding requires that the Army Health Service adapt its recommendations concerning malaria prevention in French Guiana.

Life-table studies revealed significant effects of deforestation on the development and survivorship of Anopheles minimus larvae.

PubMed

Wang, Xiaoming; Zhou, Guofa; Zhong, Daibin; Wang, Xiaoling; Wang, Ying; Yang, Zhaoqing; Cui, Liwang; Yan, Guiyun

2016-06-06

Many developing countries are experiencing rapid ecological changes such as deforestation and shifting agricultural practices. These environmental changes may have an important consequence on malaria due to their impact on vector survival and reproduction. Despite intensive deforestation and malaria transmission in the China-Myanmar border area, the impact of deforestation on malaria vectors in the border area is unknown. We conducted life table studies on Anopheles minimus larvae to determine the pupation rate and development time in microcosms under deforested, banana plantation, and forested environments. The pupation rate of An. minimus was 3.8 % in the forested environment. It was significantly increased to 12.5 % in banana plantations and to 52.5 % in the deforested area. Deforestation reduced larval-to-pupal development time by 1.9-3.3 days. Food supplementation to aquatic habitats in forested environments and banana plantations significantly increased larval survival rate to a similar level as in the deforested environment. Deforestation enhanced the survival and development of An. minimus larvae, a major malaria vector in the China-Myanmar border area. Experimental determination of the life table parameters on mosquito larvae under a variety of environmental conditions is valuable to model malaria transmission dynamics and impact by climate and environmental changes.

Deforestation and Vectorial Capacity of Anopheles gambiae Giles Mosquitoes in Malaria Transmission, Kenya

PubMed Central

Afrane, Yaw A.; Little, Tom J.; Lawson, Bernard W.; Githeko, Andrew K.

2008-01-01

We investigated the effects of deforestation on microclimates and sporogonic development of Plasmodium falciparum parasites in Anopheles gambiae mosquitoes in an area of the western Kenyan highland prone to malaria epidemics. An. gambiae mosquitoes were fed with P. falciparum–infected blood through membrane feeders. Fed mosquitoes were placed in houses in forested and deforested areas in a highland area (1,500 m above sea level) and monitored for parasite development. Deforested sites had higher temperatures and relative humidities, and the overall infection rate of mosquitoes was increased compared with that in forested sites. Sporozoites appeared on average 1.1 days earlier in deforested areas. Vectorial capacity was estimated to be 77.7% higher in the deforested site than in the forested site. We showed that deforestation changes microclimates, leading to more rapid sporogonic development of P. falciparum and to a marked increase of malaria risk in the western Kenyan highland. PMID:18826815

Plasmodium falciparum in the southeastern Atlantic forest: a challenge to the bromeliad-malaria paradigm?

PubMed

Laporta, Gabriel Zorello; Burattini, Marcelo Nascimento; Levy, Debora; Fukuya, Linah Akemi; de Oliveira, Tatiane Marques Porangaba; Maselli, Luciana Morganti Ferreira; Conn, Jan Evelyn; Massad, Eduardo; Bydlowski, Sergio Paulo; Sallum, Maria Anice Mureb

2015-04-25

Recently an unexpectedly high prevalence of Plasmodium falciparum was found in asymptomatic blood donors living in the southeastern Brazilian Atlantic forest. The bromeliad-malaria paradigm assumes that transmission of Plasmodium vivax and Plasmodium malariae involves species of the subgenus Kerteszia of Anopheles and only a few cases of P. vivax malaria are reported annually in this region. The expectations of this paradigm are a low prevalence of P. vivax and a null prevalence of P. falciparum. Therefore, the aim of this study was to verify if P. falciparum is actively circulating in the southeastern Brazilian Atlantic forest remains. In this study, anophelines were collected with Shannon and CDC-light traps in seven distinct Atlantic forest landscapes over a 4-month period. Field-collected Anopheles mosquitoes were tested by real-time PCR assay in pools of ten, and then each mosquito from every positive pool, separately for P. falciparum and P. vivax. Genomic DNA of P. falciparum or P. vivax from positive anophelines was then amplified by traditional PCR for sequencing of the 18S ribosomal DNA to confirm Plasmodium species. Binomial probabilities were calculated to identify non-random results of the P. falciparum-infected anopheline findings. The overall proportion of anophelines naturally infected with P. falciparum was 4.4% (21/480) and only 0.8% (4/480) with P. vivax. All of the infected mosquitoes were found in intermixed natural and human-modified environments and most were Anopheles cruzii (22/25 = 88%, 18 P. falciparum plus 4 P. vivax). Plasmodium falciparum was confirmed by sequencing in 76% (16/21) of positive mosquitoes, whereas P. vivax was confirmed in only 25% (1/4). Binomial probabilities suggest that P. falciparum actively circulates throughout the region and that there may be a threshold of the forested over human-modified environment ratio upon which the proportion of P. falciparum-infected anophelines increases significantly. These results show that P. falciparum actively circulates, in higher proportion than P. vivax, among Anopheles mosquitoes of fragments of the southeastern Brazilian Atlantic forest. This finding challenges the classical bromeliad-malaria paradigm, which considers P. vivax circulation as the driver for the dynamics of residual malaria transmission in this region.

Malaria in tree crop plantations in south-eastern and western provinces of Thailand.

PubMed

Singhasivanon, P; Thimasarn, K; Yimsamran, S; Linthicum, K; Nualchawee, K; Dawreang, D; Kongrod, S; Premmanisakul, N; Maneeboonyang, W; Salazar, N

1999-09-01

During the past three decades almost half of the existing natural tropical forests in Thailand were destroyed and replaced by cash crops, rubber, coffee, fruit orchards (durian, rambutan, mangosteen) and other commercial plantations. In order to determine the proportion of malaria cases contracted from such commercial plantations, an epidemiological study was conducted between June 1996 to May 1997 in two districts, one in Pong Nam Ron, located in a south-eastern province near the Cambodian border and another in Sai Yok, in a western province along the Myanmar border. Data were collected by passive case detection from patients attending the existing malaria clinics and active case detection by monthly malariometric survey in selected villages. All malaria cases were thoroughly investigated and classified according to exposure to different ecotypes prior to onset of malaria symptoms in the preceding two weeks. Malaria cases acquired from commercial plantations accounted for 35.2% and 11.2% in Pong Nam Ron and in Sai Yok districts respectively. In such plantations, most of the malaria cases were contracted from fruit orchards and to a lesser extent from rubber and teak plantations. From this study it is evident that commercial plantations provide a significant site of malaria transmission in addition to the forest and foothills areas in Southeast Asia where efficient vectors such as An. dirus and An. minimus are prevalent and have adapted to such changed ecosystems.

Epidemiological characteristics of imported and locally-acquired malaria in Singapore.

PubMed

Lee, Yong Chee Alvin; Tang, Choon Siang; Ang, Li Wei; Han, Hwi Kwang; James, Lyn; Goh, Kee Tai

2009-10-01

The objective of the study was to determine the trend of malaria, the epidemiological characteristics, the frequency of local transmission and the preventive and control measures taken. We analysed the epidemiological records of all reported malaria cases maintained by the Communicable Diseases Division, Ministry of Health, from 1983 to 2007 and the Anopheles vector surveillance data collected by the National Environment Agency during the same period. The annual incidence of reported malaria ranged from 2.9 to 11.1 per 100,000 population, with a sharp decline observed after 1997. There were 38 deaths, 92.1% due to falciparum malaria and 7.9% due to vivax malaria. Of the reported cases, 91.4% to 98.3% were imported, with about 90% originating from Southeast Asia and the Indian subcontinent. Among the various population groups with imported malaria, the proportion of cases involving work permit/employment pass holders had increased, while that of local residents had decreased. Between 74.8% and 95.1% of the local residents with imported malaria did not take personal chemoprophylaxis when they travelled overseas. Despite the extremely low Anopheles vector population, a total of 29 local outbreaks involving 196 cases occurred. Most of the larger outbreaks could be traced to foreign workers with imported relapsing vivax malaria and who did not seek medical treatment early. One of the outbreaks of 3 cases in 2007 was caused by Plasmodium knowlesi, a newly recognised simian malaria which was probably acquired in a forested area where long-tail macaques had been sighted. Singapore remains both vulnerable and receptive to the reintroduction of malaria and a high level of vigilance should be maintained indefinitely to prevent the re-establishment of endemicity. Medical practitioners should highlight the risk of malaria to travellers visiting endemic areas and also consider the possibility of simian malaria in a patient who has no recent travel history and presenting with daily fever spikes and with malaria parasite morphologically similar to that of P. malariae.

Spatial clustering and longitudinal variation of Anopheles darlingi (Diptera: Culicidae) larvae in a river of the Amazon: the importance of the forest fringe and of obstructions to flow in frontier malaria.

PubMed

Barros, F S M; Arruda, M E; Gurgel, H C; Honório, N A

2011-12-01

Deforestation has been linked to a rise in malaria prevalence. In this paper, we studied longitudinally 20 spots, including forested and deforested portions of a temporary river in a malarigenous frontier zone. Larval habitat parameters influencing distribution of Anopheles darlingi (Diptera: Culicidae) larvae were studied. We observed that larvae were clustered in forested-deforested transitions. For the first time in the literature, it was verified that parameters determining larval distribution varied from deforested to forested areas. The proximity to human dwellings was also a significant factor determining distribution, but larvae was most importantly associated with a previously undescribed parameter, the presence of small obstructions to river flow, such as tree trunks within the river channel, which caused pooling of water during the dry season ('microdams'). In deforested areas, the most important factor determining distribution of larvae was shade (reduced luminance). Larvae were absent in the entire studied area during the wet season and present in most sites during the dry season. During the wet-dry transition, larvae were found sooner in areas with microdams, than in other areas, suggesting that flow obstruction prolongs the breeding season of An. darlingi. Adult mosquito densities and malaria incidence were higher during the dry season. Our data correlate well with the published literature, including the distribution of malaria cases near the forest fringes, and has permitted the creation of a model of An. darlingi breeding, where preference for sites with reduced luminance, human presence and microdams would interact to determine larval distribution.

Multisensor earth observations to characterize wetlands and malaria epidemiology in Ethiopia

NASA Astrophysics Data System (ADS)

Midekisa, Alemayehu; Senay, Gabriel B.; Wimberly, Michael C.

2014-11-01

Malaria is a major global public health problem, particularly in Sub-Saharan Africa. The spatial heterogeneity of malaria can be affected by factors such as hydrological processes, physiography, and land cover patterns. Tropical wetlands, for example, are important hydrological features that can serve as mosquito breeding habitats. Mapping and monitoring of wetlands using satellite remote sensing can thus help to target interventions aimed at reducing malaria transmission. The objective of this study was to map wetlands and other major land cover types in the Amhara region of Ethiopia and to analyze district-level associations of malaria and wetlands across the region. We evaluated three random forests classification models using remotely sensed topographic and spectral data based on Shuttle Radar Topographic Mission (SRTM) and Landsat TM/ETM+ imagery, respectively. The model that integrated data from both sensors yielded more accurate land cover classification than single-sensor models. The resulting map of wetlands and other major land cover classes had an overall accuracy of 93.5%. Topographic indices and subpixel level fractional cover indices contributed most strongly to the land cover classification. Further, we found strong spatial associations of percent area of wetlands with malaria cases at the district level across the dry, wet, and fall seasons. Overall, our study provided the most extensive map of wetlands for the Amhara region and documented spatiotemporal associations of wetlands and malaria risk at a broad regional level. These findings can assist public health personnel in developing strategies to effectively control and eliminate malaria in the region.

Multisensor earth observations to characterize wetlands and malaria epidemiology in Ethiopia

USGS Publications Warehouse

Midekisa, Alemayehu; Senay, Gabriel; Wimberly, Michael C.

2014-01-01

Malaria is a major global public health problem, particularly in Sub-Saharan Africa. The spatial heterogeneity of malaria can be affected by factors such as hydrological processes, physiography, and land cover patterns. Tropical wetlands, for example, are important hydrological features that can serve as mosquito breeding habitats. Mapping and monitoring of wetlands using satellite remote sensing can thus help to target interventions aimed at reducing malaria transmission. The objective of this study was to map wetlands and other major land cover types in the Amhara region of Ethiopia and to analyze district-level associations of malaria and wetlands across the region. We evaluated three random forests classification models using remotely sensed topographic and spectral data based on Shuttle Radar Topographic Mission (SRTM) and Landsat TM/ETM+ imagery, respectively. The model that integrated data from both sensors yielded more accurate land cover classification than single-sensor models. The resulting map of wetlands and other major land cover classes had an overall accuracy of 93.5%. Topographic indices and subpixel level fractional cover indices contributed most strongly to the land cover classification. Further, we found strong spatial associations of percent area of wetlands with malaria cases at the district level across the dry, wet, and fall seasons. Overall, our study provided the most extensive map of wetlands for the Amhara region and documented spatiotemporal associations of wetlands and malaria risk at a broad regional level. These findings can assist public health personnel in developing strategies to effectively control and eliminate malaria in the region.

Art and theatre for health in rural Cambodia.

PubMed

Nguon, Chea; Dysoley, Lek; Davoeung, Chan; Sovann, Yok; Sanann, Nou; Sareth, Ma; Kunthea, Pich; Vuth, San; Sovann, Kem; Kol, Kayna; Heng, Chhouen; Sary, Rouen; Peto, Thomas J; Tripura, Rupam; Lim, Renly; Cheah, Phaik Yeong

2018-01-01

This article describes our experience using art and theatre to engage rural communities in western Cambodia to understand malaria and support malaria control and elimination. The project was a pilot science-arts initiative to supplement existing engagement activities conducted by local authorities. In 2016, the project was conducted in 20 villages, involved 300 community members and was attended by more than 8000 people. Key health messages were to use insecticide-treated bed-nets and repellents, febrile people should attend village malaria workers, and to raise awareness about the risk of forest-acquired malaria. Building on the experience and lessons learnt in the year prior, the 2017 project which was conducted in 15 villages involved 600 community members and attracted more than 12,000 people. In addition to the malaria theme, upon discussion with local health authorities, secondary theme (infant vaccination) was added to the 2017 project. We learnt the following lessons from our experience in Cambodia: involving local people including children from the beginning of the project and throughout the process is important; messages should be kept simple; it is necessary to take into consideration practical issues such as location and timing of the activities; and that the project should offer something unique to communities.

Current status of Plasmodium knowlesi vectors: a public health concern?

PubMed

Vythilingam, I; Wong, M L; Wan-Yussof, W S

2018-01-01

Plasmodium knowlesi a simian malaria parasite is currently affecting humans in Southeast Asia. Malaysia has reported the most number of cases and P. knowlesi is the predominant species occurring in humans. The vectors of P. knowlesi belong to the Leucosphyrus group of Anopheles mosquitoes. These are generally described as forest-dwelling mosquitoes. With deforestation and changes in land-use, some species have become predominant in farms and villages. However, knowledge on the distribution of these vectors in the country is sparse. From a public health point of view it is important to know the vectors, so that risk factors towards knowlesi malaria can be identified and control measures instituted where possible. Here, we review what is known about the knowlesi malaria vectors and ascertain the gaps in knowledge, so that future studies could concentrate on this paucity of data in-order to address this zoonotic problem.

Rapid case-based mapping of seasonal malaria transmission risk for strategic elimination planning in Swaziland

PubMed Central

2013-01-01

Background As successful malaria control programmes move towards elimination, they must identify residual transmission foci, target vector control to high-risk areas, focus on both asymptomatic and symptomatic infections, and manage importation risk. High spatial and temporal resolution maps of malaria risk can support all of these activities, but commonly available malaria maps are based on parasite rate, a poor metric for measuring malaria at extremely low prevalence. New approaches are required to provide case-based risk maps to countries seeking to identify remaining hotspots of transmission while managing the risk of transmission from imported cases. Methods Household locations and travel histories of confirmed malaria patients during 2011 were recorded through routine surveillance by the Swaziland National Malaria Control Programme for the higher transmission months of January to April and the lower transmission months of May to December. Household locations for patients with no travel history to endemic areas were compared against a random set of background points sampled proportionate to population density with respect to a set of variables related to environment, population density, vector control, and distance to the locations of identified imported cases. Comparisons were made separately for the high and low transmission seasons. The Random Forests regression tree classification approach was used to generate maps predicting the probability of a locally acquired case at 100 m resolution across Swaziland for each season. Results Results indicated that case households during the high transmission season tended to be located in areas of lower elevation, closer to bodies of water, in more sparsely populated areas, with lower rainfall and warmer temperatures, and closer to imported cases than random background points (all p < 0.001). Similar differences were evident during the low transmission season. Maps from the fit models suggested better predictive ability during the high season. Both models proved useful at predicting the locations of local cases identified in 2012. Conclusions The high-resolution mapping approaches described here can help elimination programmes understand the epidemiology of a disappearing disease. Generating case-based risk maps at high spatial and temporal resolution will allow control programmes to direct interventions proactively according to evidence-based measures of risk and ensure that the impact of limited resources is maximized to achieve and maintain malaria elimination. PMID:23398628

Rapid case-based mapping of seasonal malaria transmission risk for strategic elimination planning in Swaziland.

PubMed

Cohen, Justin M; Dlamini, Sabelo; Novotny, Joseph M; Kandula, Deepika; Kunene, Simon; Tatem, Andrew J

2013-02-11

As successful malaria control programmes move towards elimination, they must identify residual transmission foci, target vector control to high-risk areas, focus on both asymptomatic and symptomatic infections, and manage importation risk. High spatial and temporal resolution maps of malaria risk can support all of these activities, but commonly available malaria maps are based on parasite rate, a poor metric for measuring malaria at extremely low prevalence. New approaches are required to provide case-based risk maps to countries seeking to identify remaining hotspots of transmission while managing the risk of transmission from imported cases. Household locations and travel histories of confirmed malaria patients during 2011 were recorded through routine surveillance by the Swaziland National Malaria Control Programme for the higher transmission months of January to April and the lower transmission months of May to December. Household locations for patients with no travel history to endemic areas were compared against a random set of background points sampled proportionate to population density with respect to a set of variables related to environment, population density, vector control, and distance to the locations of identified imported cases. Comparisons were made separately for the high and low transmission seasons. The Random Forests regression tree classification approach was used to generate maps predicting the probability of a locally acquired case at 100 m resolution across Swaziland for each season. Results indicated that case households during the high transmission season tended to be located in areas of lower elevation, closer to bodies of water, in more sparsely populated areas, with lower rainfall and warmer temperatures, and closer to imported cases than random background points (all p < 0.001). Similar differences were evident during the low transmission season. Maps from the fit models suggested better predictive ability during the high season. Both models proved useful at predicting the locations of local cases identified in 2012. The high-resolution mapping approaches described here can help elimination programmes understand the epidemiology of a disappearing disease. Generating case-based risk maps at high spatial and temporal resolution will allow control programmes to direct interventions proactively according to evidence-based measures of risk and ensure that the impact of limited resources is maximized to achieve and maintain malaria elimination.

Multisensor earth observations to characterize wetlands and malaria epidemiology in Ethiopia

PubMed Central

Midekisa, Alemayehu; Senay, Gabriel B; Wimberly, Michael C

2014-01-01

Malaria is a major global public health problem, particularly in Sub-Saharan Africa. The spatial heterogeneity of malaria can be affected by factors such as hydrological processes, physiography, and land cover patterns. Tropical wetlands, for example, are important hydrological features that can serve as mosquito breeding habitats. Mapping and monitoring of wetlands using satellite remote sensing can thus help to target interventions aimed at reducing malaria transmission. The objective of this study was to map wetlands and other major land cover types in the Amhara region of Ethiopia and to analyze district-level associations of malaria and wetlands across the region. We evaluated three random forests classification models using remotely sensed topographic and spectral data based on Shuttle Radar Topographic Mission (SRTM) and Landsat TM/ETM+ imagery, respectively. The model that integrated data from both sensors yielded more accurate land cover classification than single-sensor models. The resulting map of wetlands and other major land cover classes had an overall accuracy of 93.5%. Topographic indices and subpixel level fractional cover indices contributed most strongly to the land cover classification. Further, we found strong spatial associations of percent area of wetlands with malaria cases at the district level across the dry, wet, and fall seasons. Overall, our study provided the most extensive map of wetlands for the Amhara region and documented spatiotemporal associations of wetlands and malaria risk at a broad regional level. These findings can assist public health personnel in developing strategies to effectively control and eliminate malaria in the region. Key Points Remote sensing produced an accurate wetland map for the Ethiopian highlands Wetlands were associated with spatial variability in malaria risk Mapping and monitoring wetlands can improve malaria spatial decision support PMID:25653462

Predicting potential ranges of primary malaria vectors and malaria in northern South America based on projected changes in climate, land cover and human population.

PubMed

Alimi, Temitope O; Fuller, Douglas O; Qualls, Whitney A; Herrera, Socrates V; Arevalo-Herrera, Myriam; Quinones, Martha L; Lacerda, Marcus V G; Beier, John C

2015-08-20

Changes in land use and land cover (LULC) as well as climate are likely to affect the geographic distribution of malaria vectors and parasites in the coming decades. At present, malaria transmission is concentrated mainly in the Amazon basin where extensive agriculture, mining, and logging activities have resulted in changes to local and regional hydrology, massive loss of forest cover, and increased contact between malaria vectors and hosts. Employing presence-only records, bioclimatic, topographic, hydrologic, LULC and human population data, we modeled the distribution of malaria and two of its dominant vectors, Anopheles darlingi, and Anopheles nuneztovari s.l. in northern South America using the species distribution modeling platform Maxent. Results from our land change modeling indicate that about 70,000 km(2) of forest land would be lost by 2050 and 78,000 km(2) by 2070 compared to 2010. The Maxent model predicted zones of relatively high habitat suitability for malaria and the vectors mainly within the Amazon and along coastlines. While areas with malaria are expected to decrease in line with current downward trends, both vectors are predicted to experience range expansions in the future. Elevation, annual precipitation and temperature were influential in all models both current and future. Human population mostly affected An. darlingi distribution while LULC changes influenced An. nuneztovari s.l. distribution. As the region tackles the challenge of malaria elimination, investigations such as this could be useful for planning and management purposes and aid in predicting and addressing potential impediments to elimination.

Wildlife disease and conservation in Hawaii: pathogenicity of avian malaria (Plasmodium relictum) in experimentally infected Iiwi (Vestiaria coccinea)

USGS Publications Warehouse

Atkinson, C.T.; Woods, K.L.; Dusek, Robert J.; Sileo, L.S.; Iko, W.M.

1995-01-01

Native Hawaiian forest birds are facing a major extinction crisis with more than 75% of species recorded in historical times either extinct or endangered. Reasons for this catastrophe include habitat destruction, competition with non-native species, and introduction of predators and avian diseases. We tested susceptibility of Iiwi (Vestiaria coccinea), a declining native species, and Nutmeg Mannikins (Lonchura punctulata), a common non-native species, to an isolate of Plasmodium relictum from the island of Hawaii. Food consumption, weight, and parasitaemia were monitored in juvenile Iiwi that were infected by either single (low-dose) or multiple (high-dose) mosquito bites. Mortality in both groups was significantly higher than in uninfected controls, reaching 100% of high-dose birds and 90% of low-dose birds. Significant declines in food consumption and a corresponding loss of body weight occurred in malaria-infected birds. Both sex and body weight had significant effects on survival time, with males more susceptible than females and birds with low initial weights more susceptible than those with higher initial weights. Gross and microscopic lesions in malaria fatalities included massive enlargement of the spleen and liver, hyperplasia of the reticuloendothelial system with extensive deposition of malarial pigment, and overwhelming anaemia in which over 30% of the circulating erythrocytes were parasitized. Nutmeg Mannikins, by contrast, were completely refractory to infection. Our findings support previous studies documenting high susceptibility of native Hawaiian forest birds to avian malaria. This disease continues to threaten remaining high elevation populations of endangered native birds.

Linking Deforestation to Malaria in the Amazon: Characterization of the Breeding Habitat of the Principal Malaria Vector, Anopheles darlingi

PubMed Central

Vittor, Amy Y.; Pan, William; Gilman, Robert H.; Tielsch, James; Glass, Gregory; Shields, Tim; Sánchez-Lozano, Wagner; Pinedo, Viviana V.; Salas-Cobos, Erit; Flores, Silvia; Patz, Jonathan A.

2009-01-01

This study examined the larval breeding habitat of a major South American malaria vector, Anopheles darlingi, in areas with varying degrees of ecologic alteration in the Peruvian Amazon. Water bodies were repeatedly sampled across 112 km of transects along the Iquitos-Nauta road in ecologically varied areas. Field data and satellite imagery were used to determine the landscape composition surrounding each site. Seventeen species of Anopheles larvae were collected. Anopheles darlingi larvae were present in 87 of 844 sites (10.3%). Sites with A. darlingi larvae had an average of 24.1% forest cover, compared with 41.0% for sites without A. darlingi (P < 0.0001). Multivariate analysis identified seasonality, algae, water body size, presence of human populations, and the amount of forest and secondary growth as significant determinants of A. darlingi presence. We conclude that deforestation and associated ecologic alterations are conducive to A. darlingi larval presence, and thereby increase malaria risk. PMID:19556558

Large-scale range collapse of Hawaiian forest birds under climate change and the need 21st century conservation options

USGS Publications Warehouse

Fortini, Lucas B.; Vorsino, Adam E.; Amidon, Fred A.; Paxton, Eben H.; Jacobi, James D.

2015-01-01

Hawaiian forest birds serve as an ideal group to explore the extent of climate change impacts on at-risk species. Avian malaria constrains many remaining Hawaiian forest bird species to high elevations where temperatures are too cool for malaria's life cycle and its principal mosquito vector. The impact of climate change on Hawaiian forest birds has been a recent focus of Hawaiian conservation biology, and has centered on the links between climate and avian malaria. To elucidate the differential impacts of projected climate shifts on species with known varying niches, disease resistance and tolerance, we use a comprehensive database of species sightings, regional climate projections and ensemble distribution models to project distribution shifts for all Hawaiian forest bird species. We illustrate that, under a likely scenario of continued disease-driven distribution limitation, all 10 species with highly reliable models (mostly narrow-ranged, single-island endemics) are expected to lose >50% of their range by 2100. Of those, three are expected to lose all range and three others are expected to lose >90% of their range. Projected range loss was smaller for several of the more widespread species; however improved data and models are necessary to refine future projections. Like other at-risk species, Hawaiian forest birds have specific habitat requirements that limit the possibility of range expansion for most species, as projected expansion is frequently in areas where forest habitat is presently not available (such as recent lava flows). Given the large projected range losses for all species, protecting high elevation forest alone is not an adequate long-term strategy for many species under climate change. We describe the types of additional conservation actions practitioners will likely need to consider, while providing results to help with such considerations.

Large-Scale Range Collapse of Hawaiian Forest Birds under Climate Change and the Need for 21st Century Conservation Options [corrected].

PubMed

Fortini, Lucas B; Vorsino, Adam E; Amidon, Fred A; Paxton, Eben H; Jacobi, James D

2015-01-01

Hawaiian forest birds serve as an ideal group to explore the extent of climate change impacts on at-risk species. Avian malaria constrains many remaining Hawaiian forest bird species to high elevations where temperatures are too cool for malaria's life cycle and its principal mosquito vector. The impact of climate change on Hawaiian forest birds has been a recent focus of Hawaiian conservation biology, and has centered on the links between climate and avian malaria. To elucidate the differential impacts of projected climate shifts on species with known varying niches, disease resistance and tolerance, we use a comprehensive database of species sightings, regional climate projections and ensemble distribution models to project distribution shifts for all Hawaiian forest bird species. We illustrate that, under a likely scenario of continued disease-driven distribution limitation, all 10 species with highly reliable models (mostly narrow-ranged, single-island endemics) are expected to lose >50% of their range by 2100. Of those, three are expected to lose all range and three others are expected to lose >90% of their range. Projected range loss was smaller for several of the more widespread species; however improved data and models are necessary to refine future projections. Like other at-risk species, Hawaiian forest birds have specific habitat requirements that limit the possibility of range expansion for most species, as projected expansion is frequently in areas where forest habitat is presently not available (such as recent lava flows). Given the large projected range losses for all species, protecting high elevation forest alone is not an adequate long-term strategy for many species under climate change. We describe the types of additional conservation actions practitioners will likely need to consider, while providing results to help with such considerations.

Spatial Repellency and the Field Evaluation of a Push-Pull Strategy for the Control of Malaria Vectors in Northern Belize, Central America

DTIC Science & Technology

2014-09-18

monitoring of knocked down mosquitoes. To control for residual chemical contamination from repellent treatments, all huts and interception traps were...to discontinue any ongoing trial if the institution is found to have contravened any of the above conditions. 7. The applicant shall cover food ...albopictus (Skuse) from Selangor, Malaysia . Trap Biomed 30:220-30 31. Cherington E, Ek E, Cho P, Burgess F, Hernandez B, et al. 2010. Forest Cover and

Therapeutic efficacy of artesunate-amodiaquine and artemether-lumefantrine combinations in the treatment of uncomplicated malaria in two ecological zones in Ghana.

PubMed

Abuaku, Benjamin; Duah, Nancy; Quaye, Lydia; Quashie, Neils; Malm, Keziah; Bart-Plange, Constance; Koram, Kwadwo

2016-01-05

Case management based on prompt diagnosis and adequate treatment using artemisinin-based combination therapy (ACT) remains the main focus of malaria control in Ghana. As part of routine surveillance on the therapeutic efficacy of ACT in Ghana, the efficacy of amodiaquine-artesunate (AS-AQ) and artemether-lumefantrine (AL) were studied in six sentinel sites representing the forest and savannah zones of the country. Three sites representing the two ecological zones studied AS-AQ whilst the other three sites studied AL. In each site, the study was a one-arm prospective evaluation of the clinical, parasitological, and haematological responses to directly observed therapy for uncomplicated malaria with either AS-AQ or AL among children aged 6 months and 9 years. The WHO 2009 protocol for monitoring anti-malarial drug efficacy was used for the study between July 2013 and March 2014. Per-protocol analyses on day 28 showed an overall PCR-corrected cure rate of 100% for AS-AQ and 97.6% (95% CI 93.1, 99.5) for AL: 97.2% (95% CI 92.0, 99.4) in the forest zone and 100% in the savannah zone. Kaplan-Meier survival analysis showed similar outcomes. Prevalence of fever decreased by about 75% after the first day of treatment with each ACT in the two ecological zones. No child studied was parasitaemic on day 3, and gametocytaemia was generally maintained at low levels (<5%). Post-treatment mean haemoglobin concentrations significantly increased in the two ecological zones. Therapeutic efficacy of AS-AQ and AL remains over 90% in the forest and savannah zones of Ghana. Additionally, post-treatment parasitaemia on day 3 is rare suggesting that artemisinin is still efficacious in Ghana.

[Will climate and demography have a major impact on malaria in sub-Saharan Africa in the next 20 years?].

PubMed

Saugeon, C; Baldet, T; Akogbeto, M; Henry, M C

2009-04-01

The purpose of this review of the literature is to present factors possibly affecting the spread of malaria in sub-Saharan Africa over the next 20 years. Malaria is a vector-borne disease that depends on environmental and human constraints. The main environmental limitations involve susceptibility of the vector (mosquitoes of the Anopheles genus) and parasite (Plasmodium falciparum) to climate. Malaria is a stable, endemic disease over most of the African continent. Climatic change can only affect a few regions on the fringes of stable zones (e.g. altitude areas or Sahel) where malaria is an unstable, epidemic disease. Higher temperatures could induce a decrease of malaria transmission in regions of the Sahel or an increase in the highlands. The extent of these overall trends will depend on the unpredictable occurrence of major meteorological phenomenon as well as on human activities affecting the environment that could lead to dramatic but limited outbreaks in some locations. The most influential human factors could be runaway demographic growth and urban development. Estimations based on modeling studies indicate that urbanization will lead to a 53.5% drop in exposure to malaria by 2030. However this reduction could be less than expected because of adaptation of Anopheles gambiae and An. arabiensis, the main vectors of malaria in sub-Saharan Africa, to the urban environment as well as increasing vector resistance to insecticides. Another unforeseeable factor that could induce unexpected malaria epidemics is mass migration due to war or famine. Finally immunosuppressive illnesses (e.g. HIV and malnutrition) could alter individual susceptibility to malaria. Social constraints also include human activities that modify land use. In this regard land use (e.g. forest clearance and irrigation) is known to influence the burden of malaria that is itself dependent on local determinants of transmission. Overall the most important social constraint for the population will be access to malarial prevention and implementation action to control this scourge.

Cost-Effectiveness of Long-Lasting Insecticide-Treated Hammocks in Preventing Malaria in South-Central Vietnam

PubMed Central

Morel, Chantal M.; Thang, Ngo Duc; Erhart, Annette; Xa, Nguyen Xuan; Peeters Grietens, Koen; Xuan Hung, Le; Thuan, Le Khan; Van Ky, Pham; Hung, Nguyen Manh; Coosemans, Marc; D'Alessandro, Umberto; Mills, Anne

2013-01-01

Background Despite much success in reducing the burden of malaria in Vietnam, pockets of malaria persist and eliminating them remains an important development goal. In central Vietnam, insecticide-treated hammocks have recently been introduced to help counter the disease in the highly forested, mountainous areas, where other measures have so far been unsuccessful. This study assesses the cost-effectiveness of using long-lasting insecticide-treated hammocks in this area. Methods and Findings This cost-effectiveness study was run alongside a randomized control trial testing the efficacy of the long-lasting insecticide-treated hammocks. Data were collected through an exit survey, a household survey, expenditure records and key informant interviews. The study estimates that under normal (non-trial) conditions the total net societal cost per malaria episode averted in using long-lasting insecticide-treated hammocks in this area was 126 USD. Cost per hammock, including insecticidal netting, sewing, transport, and distribution was found to be approximately 11.76 USD per hammock. Average savings per episode averted were estimated to be $14.60 USD for the health system and 14.37 USD for households (including both direct and indirect cost savings). The study estimates that the annual financial outlay required of government to implement this type of programme to be 3.40 USD per person covered per year. Conclusion The study finds that the use of a hammock intervention could represent good value for money to help prevent malaria in more remote areas, where traditional control measures such as insecticide-treated bednets and indoor residual spraying are insufficient or inappropriate to control malaria. However, the life span of the hammock–the number of years over which it effectively deters mosquitoes–has a significant impact on the cost-effectiveness of the intervention and study results should be interpreted in light of the evidence on effectiveness gathered in the years to come. PMID:23536790

Seasonal prevalence of malaria vectors and entomological inoculation rates in the rubber cultivated area of Niete, South Region of Cameroon

PubMed Central

2012-01-01

Background Development of large scale agro-industries are subject to serious environmental modifications. In malaria endemic areas this would greatly impact on the transmission paradigm. Two cross-sectional entomological surveys to characterize the Anopheles fauna and their entomological inoculation rates were conducted during May 2010 (peak rainy season) and December 2010 (peak dry season) in the intense rubber cultivated area of Niete in southern forested Cameroon. Methods Mosquitoes were sampled by night collections on human volunteers, identified morphologically and members of the Anopheles gambiae complex further identified to species and molecular form. Parity status was determined following the dissection of the ovaries. Plasmodium falciparum circumsporozoite antigen indices were estimated after the identification of CS antigen by ELISA and the average entomological inoculation rates determined. Results A total of 1187 Anopheles was collected, 419 (35.3%) in the rainy season and 768 (64.7%) in the dry season. Species found were the M molecular form of An. gambiae s.s (66.8%), An. ziemanni (28.3%), An. paludis (4.7%), An. smithii (0.2%). An. gambiae M-form was the principal species in the dry (56.2%) and wet (86.2%) seasons. Average overall entomological inoculation rate for the malaria vectors varied between the dry season (1.09 ib/p/n) and the rainy season (2.30 ib/p/n). Conclusions Malaria transmission in Niete occurs both in the dry and rainy season with the intensities peaking in the dry season. This is unlike previous studies in other areas of southern forested Cameroon where transmission generally peaks in the rainy season. Environmental modifications due to agro-industrial activities might have influenced vector distribution and the dynamics of malaria transmission in this area. This necessitates the possible implementation of control strategies that are related to the eco-geography of the area. PMID:22963986

Preliminary Biological Studies on Larvae and Adult Anopheles Mosquitoes (Diptera: Culicidae) in Miraflores, a Malaria Endemic Locality in Guaviare Department, Amazonian Colombia

PubMed Central

JIMÉNEZ, IRENE P.; CONN, JAN E.; BROCHERO, HELENA

2015-01-01

In the malaria endemic municipality of Miraflores in southeastern Amazonian Colombia, several aspects of the biology of local Anopheles species were investigated to supplement the limited entomological surveillance information available and to provide baseline data for malaria prevention and vector control. Anopheles darlingi Root, 1926 was the most abundant species (95.6%), followed by Anopheles braziliensis (Chagas) (3.6%) and Anopheles oswaldoi s.l. (Peryassu) (0.7%). During the dry season, exophagic activity was prevalent only between 1800–2100 hours; after this (2100–0600 hours) only endophagy was encountered. In contrast, during the rainy season, both endophagy and exophagy occurred throughout the collection period. The human biting rate for An. darlingi was 8.6. This species was positive for Plasmodium vivax VK210 with a sporozoite rate = 0.13 (1/788). Breeding sites corresponded to stream (n = 7), flooded excavations (n = 4), flooded forest (n = 1), wetlands (n = 2), and an abandoned water reservoir (n = 1). An. darlingi predominated in these sites in both seasons. Based on these data, An. darlingi is the main local malaria vector, and we recommend that local prevention and control efforts focus on strengthening entomological surveillance to determine potential changes of species biting behavior and time to reduce human–vector interactions. PMID:25276930

Outbreak of human malaria caused by Plasmodium simium in the Atlantic Forest in Rio de Janeiro: a molecular epidemiological investigation.

PubMed

Brasil, Patrícia; Zalis, Mariano Gustavo; de Pina-Costa, Anielle; Siqueira, Andre Machado; Júnior, Cesare Bianco; Silva, Sidnei; Areas, André Luiz Lisboa; Pelajo-Machado, Marcelo; de Alvarenga, Denise Anete Madureira; da Silva Santelli, Ana Carolina Faria; Albuquerque, Hermano Gomes; Cravo, Pedro; Santos de Abreu, Filipe Vieira; Peterka, Cassio Leonel; Zanini, Graziela Maria; Suárez Mutis, Martha Cecilia; Pissinatti, Alcides; Lourenço-de-Oliveira, Ricardo; de Brito, Cristiana Ferreira Alves; de Fátima Ferreira-da-Cruz, Maria; Culleton, Richard; Daniel-Ribeiro, Cláudio Tadeu

2017-10-01

Malaria was eliminated from southern and southeastern Brazil over 50 years ago. However, an increasing number of autochthonous episodes attributed to Plasmodium vivax have recently been reported from the Atlantic Forest region of Rio de Janeiro state. As the P vivax-like non-human primate malaria parasite species Plasmodium simium is locally enzootic, we performed a molecular epidemiological investigation to determine whether zoonotic malaria transmission is occurring. We examined blood samples from patients presenting with signs or symptoms suggestive of malaria as well as from local howler monkeys by microscopy and PCR. Samples were included from individuals if they had a history of travel to or resided in areas within the Rio de Janeiro Atlantic Forest, but not if they had malaria prophylaxis, blood transfusion or tissue or organ transplantation, or had travelled to known malaria endemic areas in the preceding year. Additionally, we developed a molecular assay based on sequencing of the parasite mitochondrial genome to distinguish between P vivax and P simium, and applied this assay to 33 cases from outbreaks that occurred in 2015, and 2016. A total of 49 autochthonous malaria cases were reported in 2015-16. Most patients were male, with a mean age of 44 years (SD 14·6), and 82% lived in urban areas of Rio de Janeiro state and had visited the Atlantic Forest for leisure or work-related activities. 33 cases were used for mitochondrial DNA sequencing. The assay was successfully performed for 28 samples, and all were shown to be P simium, indicative of zoonotic transmission of this species to human beings in this region. Sequencing of the whole mitochondrial genome of three of these cases showed that P simium is most closely related to P vivax parasites from South America. The malaria outbreaks in this region were caused by P simium, previously considered to be a monkey-specific malaria parasite, related to but distinct from P vivax, and which has never conclusively been shown to infect people before. This unequivocal demonstration of zoonotic transmission, 50 years after the only previous report of P simium in people, leads to the possibility that this parasite has always infected people in this region, but that it has been consistently misdiagnosed as P vivax because of an absence of molecular typing techniques. Thorough screening of local non-human primates and mosquitoes (Anopheline) is required to evaluate the extent of this newly recognised zoonotic threat to public health and malaria elimination in Brazil. Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado de Rio de Janeiro, The Brazilian National Council for Scientific and Technological Development (CNPq), JSPS Grant-in-Aid for scientific research, Secretary for Health Surveillance of the Brazilian Ministry of Health, Global Fund, Fundaçao de amparo à pesquisa do estado de Minas Gerais (Fapemig), and PRONEX Program of the CNPq. Copyright © 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license. Published by Elsevier Ltd.. All rights reserved.

Does deforestation promote or inhibit malaria transmission in the Amazon? A systematic literature review and critical appraisal of current evidence

PubMed Central

Tucker Lima, Joanna M.; Vittor, Amy; Rifai, Sami

2017-01-01

Considerable interest in the relationship between biodiversity and disease has recently captured the attention of the research community, with important public policy implications. In particular, malaria in the Amazon region is often cited as an example of how forest conservation can improve public health outcomes. However, despite a growing body of literature and an increased understanding of the relationship between malaria and land use / land cover change (LULC) in Amazonia, contradictions have emerged. While some studies report that deforestation increases malaria risk, others claim the opposite. Assessing malaria risk requires examination of dynamic processes among three main components: (i) the environment (i.e. LULC and landscape transformations), (ii) vector biology (e.g. mosquito species distributions, vector activity and life cycle, plasmodium infection rates), and (iii) human populations (e.g. forest-related activity, host susceptibility, movement patterns). In this paper, we conduct a systematic literature review on malaria risk and deforestation in the Amazon focusing on these three components. We explore key features that are likely to generate these contrasting results using the reviewed articles and our own data from Brazil and Peru, and conclude with suggestions for productive avenues in future research. This article is part of the themed issue ‘Conservation, biodiversity and infectious disease: scientific evidence and policy implications'. PMID:28438914

Does deforestation promote or inhibit malaria transmission in the Amazon? A systematic literature review and critical appraisal of current evidence.

PubMed

Tucker Lima, Joanna M; Vittor, Amy; Rifai, Sami; Valle, Denis

2017-06-05

Considerable interest in the relationship between biodiversity and disease has recently captured the attention of the research community, with important public policy implications. In particular, malaria in the Amazon region is often cited as an example of how forest conservation can improve public health outcomes. However, despite a growing body of literature and an increased understanding of the relationship between malaria and land use / land cover change (LULC) in Amazonia, contradictions have emerged. While some studies report that deforestation increases malaria risk, others claim the opposite. Assessing malaria risk requires examination of dynamic processes among three main components: (i) the environment (i.e. LULC and landscape transformations), (ii) vector biology (e.g. mosquito species distributions, vector activity and life cycle, plasmodium infection rates), and (iii) human populations (e.g. forest-related activity, host susceptibility, movement patterns). In this paper, we conduct a systematic literature review on malaria risk and deforestation in the Amazon focusing on these three components. We explore key features that are likely to generate these contrasting results using the reviewed articles and our own data from Brazil and Peru, and conclude with suggestions for productive avenues in future research.This article is part of the themed issue 'Conservation, biodiversity and infectious disease: scientific evidence and policy implications'. © 2017 The Authors.

Fuzzy association rule mining and classification for the prediction of malaria in South Korea.

PubMed

Buczak, Anna L; Baugher, Benjamin; Guven, Erhan; Ramac-Thomas, Liane C; Elbert, Yevgeniy; Babin, Steven M; Lewis, Sheri H

2015-06-18

Malaria is the world's most prevalent vector-borne disease. Accurate prediction of malaria outbreaks may lead to public health interventions that mitigate disease morbidity and mortality. We describe an application of a method for creating prediction models utilizing Fuzzy Association Rule Mining to extract relationships between epidemiological, meteorological, climatic, and socio-economic data from Korea. These relationships are in the form of rules, from which the best set of rules is automatically chosen and forms a classifier. Two classifiers have been built and their results fused to become a malaria prediction model. Future malaria cases are predicted as Low, Medium or High, where these classes are defined as a total of 0-2, 3-16, and above 17 cases, respectively, for a region in South Korea during a two-week period. Based on user recommendations, HIGH is considered an outbreak. Model accuracy is described by Positive Predictive Value (PPV), Sensitivity, and F-score for each class, computed on test data not previously used to develop the model. For predictions made 7-8 weeks in advance, model PPV and Sensitivity are 0.842 and 0.681, respectively, for the HIGH classes. The F0.5 and F3 scores (which combine PPV and Sensitivity) are 0.804 and 0.694, respectively, for the HIGH classes. The overall FARM results (as measured by F-scores) are significantly better than those obtained by Decision Tree, Random Forest, Support Vector Machine, and Holt-Winters methods for the HIGH class. For the Medium class, Random Forest and FARM obtain comparable results, with FARM being better at F0.5, and Random Forest obtaining a higher F3. A previously described method for creating disease prediction models has been modified and extended to build models for predicting malaria. In addition, some new input variables were used, including indicators of intervention measures. The South Korea malaria prediction models predict Low, Medium or High cases 7-8 weeks in the future. This paper demonstrates that our data driven approach can be used for the prediction of different diseases.

A zoonotic human infection with simian malaria, Plasmodium knowlesi, in Central Kalimantan, Indonesia.

PubMed

Setiadi, Wuryantari; Sudoyo, Herawati; Trimarsanto, Hidayat; Sihite, Boy Adventus; Saragih, Riahdo Juliarman; Juliawaty, Rita; Wangsamuda, Suradi; Asih, Puji Budi Setia; Syafruddin, Din

2016-04-16

The Indonesian archipelago is endemic for malaria. Although Plasmodium falciparum and P. vivax are the most common causes for malaria cases, P. malariae and P. ovale are also present in certain regions. Zoonotic case of malaria had just became the attention of public health communities after the Serawak study in 2004. However, zoonotic case in Indonesia is still under reported; only one published report of knowlesi malaria in South Kalimantan in 2010. A case of Plasmodium knowlesi infection in a worker from a charcoal mining company in Central Kalimantan, Indonesia was described. The worker suffered from fever following his visit to a lowland forest being cut and converted into a new mining location. This study confirmed a zoonotic infection using polymerase chain reaction amplification and Sanger sequencing of plasmodial DNA encoding the mitochondrial cytochrome c oxidase subunit I (mtCOI).

Investigation of a Sudden Malaria Outbreak in the Isolated Amazonian Village of Saül, French Guiana, January–April 2009

PubMed Central

Berger, Franck; Flamand, Claude; Musset, Lise; Djossou, Félix; Rosine, Jacques; Sanquer, Marie-Anne; Dusfour, Isabelle; Legrand, Eric; Ardillon, Vanessa; Rabarison, Patrick; Grenier, Claire; Girod, Romain

2012-01-01

Malaria is endemic in French Guiana. Plasmodium falciparum and Plasmodium vivax are the predominant species responsible and Anopheles darlingi is described as the major vector. In mid-August 2008, an increase in malaria incidence was observed in Saül. A retrospective cohort survey was performed. In vitro susceptibility profiles to antimalarials were determined on P. falciparum isolates. Collections of mosquitoes were organized. The malaria attack rate reached 70.6/100. The risk of malaria increased for people between 40 and 49 years of age, living in a house not subjected to a recent indoor residual insecticide spraying or staying overnight in the surrounding forest. All isolates were susceptible. Anopheles darlingi females and larvae were collected in the village suggesting a local transmission. Our results strongly support a role of illegal mining activities in the emergence of new foci of malaria. Therefore, public health authorities should define policies to fight malaria at a transborder level. PMID:22492141

Ecological transition from natural forest to tea plantations: effect on the dynamics of malaria vectors in the highlands of Cameroon.

PubMed

Tanga, M C; Ngundu, W I

2010-10-01

From October 2002 to September 2003, an entomological survey was carried out in a rural forested fringed village in the highlands of Mount Cameroon region to determine the temporal dynamics of the anopheline population and the intensity of malaria transmission. A total of 2387 Anopheles spp. were collected, with A. funestus predominating (59.9%), followed by A. hancocki (24.4%) and A. gambiae s.l. (15.7%). Considerable differences were observed in the nocturnal biting cycles of parous mosquitoes, with peak activity in the latter part of the night. PCR revealed that all specimens of the A. funestus group were A. funestus s.s. and all specimens from the A. gambiae complex were A. gambiae s.s. of the S molecular form. Plasmodium falciparum sporozoite rates of 17.3% and 8.5% were recorded for A. funestus and A. hancocki, respectively, with an anthropophilic rate of 96.3%. A strong positive correlation (r=0.996) was found between the human-biting rate and the entomological inoculation rate (EIR). Malaria transmission was very high and perennial, with an estimated annual EIR of 460.1 infective bites per person per year. These results confirm that in high agricultural activity areas, A. funestus can be by far the major malaria vector responsible for malaria transmission. Copyright © 2010 Royal Society of Tropical Medicine and Hygiene.

An epidemiological overview of malaria in Bangladesh.

PubMed

Islam, Nazrul; Bonovas, Stefanos; Nikolopoulos, Georgios K

2013-01-01

Bangladesh is one of the four major malaria-endemic countries in South-East Asia having approximately 34% of its population at risk of malaria. This paper aims at providing an overview of the malaria situation in this country. Relevant information was retrieved from published articles and reports in PubMed and Google Scholar. Malaria in Bangladesh is concentrated in 13 districts with a prevalence ranging between 3.1% and 36%, and is mostly caused by Plasmodium falciparum. Geographical conditions pose a potential risk for Plasmodium knowlesi malaria. Resistance to a number of drugs previously recommended for treatment has been reported. Low socio-economic status, poor schooling and close proximity to water bodies and forest areas comprise important risk factors. Despite the significant steps in Long Lasting Insecticide Net (LLIN)/Insecticide Treated Net (ITN) coverage in Bangladesh, there are still many challenges including the extension of malaria support to the remote areas of Bangladesh, where malaria prevalence is higher, and further improvements in the field of referral system and treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

Spatial clustering and risk factors of malaria infections in Bata district, Equatorial Guinea.

PubMed

Gómez-Barroso, Diana; García-Carrasco, Emely; Herrador, Zaida; Ncogo, Policarpo; Romay-Barja, María; Ondo Mangue, Martín Eka; Nseng, Gloria; Riloha, Matilde; Santana, Maria Angeles; Valladares, Basilio; Aparicio, Pilar; Benito, Agustín

2017-04-12

The transmission of malaria is intense in the majority of the countries of sub-Saharan Africa, particularly in those that are located along the Equatorial strip. The present study aimed to describe the current distribution of malaria prevalence among children and its environment-related factors as well as to detect malaria spatial clusters in the district of Bata, in Equatorial Guinea. From June to August 2013 a representative cross-sectional survey using a multistage, stratified, cluster-selected sample was carried out of children in urban and rural areas of Bata District. All children were tested for malaria using rapid diagnostic tests (RDTs). Results were linked to each household by global position system data. Two cluster analysis methods were used: hot spot analysis using the Getis-Ord Gi statistic, and the SaTScan™ spatial statistic estimates, based on the assumption of a Poisson distribution to detect spatial clusters. In addition, univariate associations and Poisson regression model were used to explore the association between malaria prevalence at household level with different environmental factors. A total of 1416 children aged 2 months to 15 years living in 417 households were included in this study. Malaria prevalence by RDTs was 47.53%, being highest in the age group 6-15 years (63.24%, p < 0.001). Those children living in rural areas were there malaria risk is greater (65.81%) (p < 0.001). Malaria prevalence was higher in those houses located <1 km from a river and <3 km to a forest (IRR: 1.31; 95% CI 1.13-1.51 and IRR: 1.44; 95% CI 1.25-1.66, respectively). Poisson regression analysis also showed a decrease in malaria prevalence with altitude (IRR: 0.73; 95% CI 0.62-0.86). A significant cluster inland of the district, in rural areas has been found. This study reveals a high prevalence of RDT-based malaria among children in Bata district. Those households situated in inland rural areas, near to a river, a green area and/or at low altitude were a risk factor for malaria. Spatial tools can help policy makers to promote new recommendations for malaria control.

Mosquito Larval Habitats, Land Use, and Potential Malaria Risk in Northern Belize from Satellite Image Analyses

NASA Technical Reports Server (NTRS)

Pope, Kevin; Masuoka, Penny; Rejmankova, Eliska; Grieco, John; Johnson, Sarah; Roberts, Donald

2004-01-01

The distribution of Anopheles mosquito habitats and land use in northern Belize is examined with satellite data. -A land cover classification based on multispectral SPOT and multitemporal Radarsat images identified eleven land cover classes, including agricultural, forest, and marsh types. Two of the land cover types, Typha domingensis marsh and flooded forest, are Anopheles vestitipennis larval habitats. Eleocharis spp. marsh is the larval habitat for Anopheles albimanus. Geographic Information Systems (GIS) analyses of land cover demonstrate that the amount of T-ha domingensis in a marsh is positively correlated with the amount of agricultural land in the adjacent upland, and negatively correlated with the amount of adjacent forest. This finding is consistent with the hypothesis that nutrient (phosphorus) runoff from agricultural lands is causing an expansion of Typha domingensis in northern Belize. This expansion of Anopheles vestitipennis larval habitat may in turn cause an increase in malaria risk in the region.

Association between Landscape Factors and Spatial Patterns of Plasmodium knowlesi Infections in Sabah, Malaysia

PubMed Central

Abidin, Tommy Rowel; Alexander, Neal; Brock, Paddy; Grigg, Matthew J.; Murphy, Amanda; William, Timothy; Menon, Jayaram; Drakeley, Chris J.; Cox, Jonathan

2016-01-01

The zoonotic malaria species Plasmodium knowlesi has become the main cause of human malaria in Malaysian Borneo. Deforestation and associated environmental and population changes have been hypothesized as main drivers of this apparent emergence. We gathered village-level data for P. knowlesi incidence for the districts of Kudat and Kota Marudu in Sabah state, Malaysia, for 2008–2012. We adjusted malaria records from routine reporting systems to reflect the diagnostic uncertainty of microscopy for P. knowlesi. We also developed negative binomial spatial autoregressive models to assess potential associations between P. knowlesi incidence and environmental variables derived from satellite-based remote-sensing data. Marked spatial heterogeneity in P. knowlesi incidence was observed, and village-level numbers of P. knowlesi cases were positively associated with forest cover and historical forest loss in surrounding areas. These results suggest the likelihood that deforestation and associated environmental changes are key drivers in P. knowlesi transmission in these areas. PMID:26812373

Experimental evidence for evolved tolerance to avian malaria in a wild population of low elevation Hawai`i `Amakihi (Hemignathus virens)

USGS Publications Warehouse

Atkinson, Carter T.; Saili, Katerine S.; Utzurrum, Ruth B.; Jarvi, Susan I.

2013-01-01

Introduced vector-borne diseases, particularly avian malaria (Plasmodium relictum) and avian pox virus (Avipoxvirus spp.), continue to play significant roles in the decline and extinction of native forest birds in the Hawaiian Islands. Hawaiian honeycreepers are particularly susceptible to avian malaria and have survived into this century largely because of persistence of high elevation refugia on Kaua‘i, Maui, and Hawai‘i Islands, where transmission is limited by cool temperatures. The long term stability of these refugia is increasingly threatened by warming trends associated with global climate change. Since cost effective and practical methods of vector control in many of these remote, rugged areas are lacking, adaptation through processes of natural selection may be the best long-term hope for recovery of many of these species. We document emergence of tolerance rather than resistance to avian malaria in a recent, rapidly expanding low elevation population of Hawai‘i ‘Amakihi (Hemignathus virens) on the island of Hawai‘i. Experimentally infected low elevation birds had lower mortality, lower reticulocyte counts during recovery from acute infection, lower weight loss, and no declines in food consumption relative to experimentally infected high elevation Hawai‘i ‘Amakihi in spite of similar intensities of infection. Emergence of this population provides an exceptional opportunity for determining physiological mechanisms and genetic markers associated with malaria tolerance that can be used to evaluate whether other, more threatened species have the capacity to adapt to this disease.

Hospitalizations and Costs Incurred at the Facility Level after Scale-up of Malaria Control: Pre-Post Comparisons from Two Hospitals in Zambia

PubMed Central

Comfort, Alison B.; van Dijk, Janneke H.; Mharakurwa, Sungano; Stillman, Kathryn; Gabert, Rose; Korde, Sonali; Nachbar, Nancy; Derriennic, Yann; Musau, Stephen; Hamazakaza, Petan; Zyambo, Khozya D.; Zyongwe, Nancy M.; Hamainza, Busiku; Thuma, Philip E.

2014-01-01

There is little evidence on the impact of malaria control on the health system, particularly at the facility level. Using retrospective, longitudinal facility-level and patient record data from two hospitals in Zambia, we report a pre-post comparison of hospital admissions and outpatient visits for malaria and estimated costs incurred for malaria admissions before and after malaria control scale-up. The results show a substantial reduction in inpatient admissions and outpatient visits for malaria at both hospitals after the scale-up, and malaria cases accounted for a smaller proportion of total hospital visits over time. Hospital spending on malaria admissions also decreased. In one hospital, malaria accounted for 11% of total hospital spending before large-scale malaria control compared with < 1% after malaria control. The findings demonstrate that facility-level resources are freed up as malaria is controlled, potentially making these resources available for other diseases and conditions. PMID:24218409

Bionomics of Anopheles latens in Kapit, Sarawak, Malaysian Borneo in relation to the transmission of zoonotic simian malaria parasite Plasmodium knowlesi

PubMed Central

Tan, Cheong H; Vythilingam, Indra; Matusop, Asmad; Chan, Seng T; Singh, Balbir

2008-01-01

Background A large focus of human infections with Plasmodium knowlesi, a simian parasite naturally found in long-tailed and pig-tailed macaques was discovered in the Kapit Division of Sarawak, Malaysian Borneo. A study was initiated to identify the vectors of malaria, to elucidate where transmission is taking place and to understand the bionomics of the vectors in Kapit. Methods Three different ecological sites in the forest, farm and longhouse in the Kapit district were selected for the study. Mosquitoes were collected by human landing collection at all sites and at the forest also by monkey-baited-traps situated on three different levels. All mosquitoes were identified and salivary glands and midguts of anopheline mosquitoes were dissected to determine the presence of malaria parasites. Results and Discussions Over an 11-month period, a total of 2,504 Anopheles mosquitoes comprising 12 species were caught; 1,035 at the farm, 774 at the forest and 425 at the longhouse. Anopheles latens (62.3%) and Anopheles watsonii (30.6%) were the predominant species caught in the forested ecotypes, while in the farm Anopheles donaldi (49.9%) and An. latens (35.6%) predominated. In the long house, An. latens (29.6%) and An. donaldi (22.8%) were the major Anopheline species. However, An. latens was the only mosquito positive for sporozoites and it was found to be attracted to both human and monkey hosts. In monkey-baited net traps, it preferred to bite monkeys at the canopy level than at ground level. An. latens was found biting early as 18.00 hours. Conclusion Anopheles latens is the main vector for P. knowlesi malaria parasites in the Kapit District of Sarawak, Malaysian Borneo. The study underscores the relationship between ecology, abundance and bionomics of anopheline fauna. The simio-anthropophagic and acrodendrophilic behaviour of An. latens makes it an efficient vector for the transmission of P. knowlesi parasites to both human and monkey hosts. PMID:18377652

The use of a GIS-based malaria information system for malaria research and control in South Africa.

PubMed

Martin, Carrin; Curtis, Bronwyn; Fraser, Colleen; Sharp, Brian

2002-12-01

The paper aims to outline the innovative development and application of a Geographical Information System based Malaria Information System for malaria research and control in South Africa. This system is a product of collaboration between the Malaria Control Programmes and the Malaria Research Programme of the Medical Research Council of South Africa. The ability of such a system to process data timeously into a usable format is discussed, as well as its relevance to malaria research, appropriate malaria control measures, tourism, and social and economic development.

Human behavior and malaria.

PubMed

Hongvivatana, T

1986-09-01

Human behavior in malaria is often narrowly referred to behavior of the target populations in transmission and control of malaria. In this presentation it was discussed that such view is too narrow. A broader framework incorporating illness behavior and human behavior in malaria control bureaucracies is needed for the success of national malaria control programme. Literature under the three broad categories of human behavior in malaria is reviewed to justify future directions in human behavior research and their significance for successful malaria control.

Malaria remedies of the Kenyah of the Apo Kayan, East Kalimantan, Indonesian Borneo: a quantitative assessment of local consensus as an indicator of biological efficacy.

PubMed

Leaman, D J; Arnason, J T; Yusuf, R; Sangat-Roemantyo, H; Soedjito, H; Angerhofer, C K; Pezzuto, J M

1995-11-17

Traditional remedies have been a source of important antimalarial drugs and continue to provide novel and effective treatments, both where pharmaceuticals are not available and where the disease is increasingly resistant to commonly prescribed drugs. The Kenyah of the Apo Kayan, a remote forested plateau in Indonesian Borneo, use 17 malaria remedies derived from natural sources. A quantitative analysis of the relationship between a 'local importance value' index for each malaria remedy (IVmal) and inhibition of cultured Plasmodium falciparum by ethanolic extracts supports the hypothesis that the degree of local consensus about a given remedy is a good indicator of its potential biological efficacy. Our results confirm the rational selection and use of traditional remedies for malaria by the Kenyah. We have identified target species for further research directed toward safe and effective treatments for malaria.

Malaria, a difficult diagnosis in a febrile patient with sub-microscopic parasitaemia and polyclonal lymphocyte activation outside the endemic region, in Brazil

PubMed Central

2013-01-01

A case of autochthonous Plasmodium vivax malaria with sub-microscopic parasitaemia and polyclonal B-cell activation (PBA) (as reflected by positive IgM and IgG serology for toxoplasmosis, cytomegalovirus, and antinuclear and rheumatoid factors) was diagnosed by polymerase chain reaction (PCR) after consecutive negative rapid diagnostic test results and blood films. The patient, a 44-year-old man from Rio de Janeiro state, Brazil, had visited the Atlantic Forest, a tourist, non-malaria-endemic area where no autochthonous cases of ’bromeliad malaria‘ has ever been described. The characteristic pattern of fever, associated with PBA, was the clue to malaria diagnosis, despite consecutive negative thick blood smears. The study highlights a need for changes in clinical and laboratory diagnostic approaches, namely the incorporation of PCR as part of the current routine malaria diagnostic methods in non-endemic areas. PMID:24200365

Effect of anti-malarial interventions on trends of malaria cases, hospital admissions and deaths, 2005-2015, Ghana.

PubMed

Aregawi, Maru; Malm, Keziah L; Wahjib, Mohammed; Kofi, Osae; Allotey, Naa-Korkor; Yaw, Peprah Nana; Abba-Baffoe, Wilmot; Segbaya, Sylvester; Owusu-Antwi, Felicia; Kharchi, Abderahmane T; Williams, Ryan O; Saalfeld, Mark; Workneh, Nibretie; Shargie, Estifanos Biru; Noor, Abdisalan M; Bart-Plange, Constance

2017-04-26

Since 2005, the Government of Ghana and its partners, in concerted efforts to control malaria, scaled up the use of artemisinin-based combination therapy (ACT) and insecticide-treated nets (ITNs). Beginning in 2011, a mass campaign of long-lasting insecticidal nets (LLINs) was implemented, targeting all the population. The impact of these interventions on malaria cases, admissions and deaths was assessed using data from district hospitals. Records of malaria cases and deaths and availability of ACT in 88 hospitals, as well as at district level, ITN distribution, and indoor residual spraying were reviewed. Annual proportion of the population potentially protected by ITNs was estimated with the assumption that each LLIN covered 1.8 persons for 3 years. Changes in trends of cases and deaths in 2015 were estimated by segmented log-linear regression, comparing trends in post-scale-up (2011-2015) with that of pre-scale-up (2005-2010) period. Trends of mortality in children under 5 years old from population-based household surveys were also compared with the trends observed in hospitals for the same time period. Among all ages, the number of outpatient malaria cases (confirmed and presumed) declined by 57% (95% confidence interval [CI], 47-66%) by first half of 2015 (during the post-scale-up) compared to the pre-scale-up (2005-2010) period. The number of microscopically confirmed cases decreased by 53% (28-69%) while microscopic testing was stable. Test positivity rate (TPR) decreased by 41% (19-57%). The change in malaria admissions was insignificant while malaria deaths fell significantly by 65% (52-75%). In children under 5 years old, total malaria outpatient cases, admissions and deaths decreased by 50% (32-63%), 46% (19-75%) and 70% (49-82%), respectively. The proportion of outpatient malaria cases, admissions and deaths of all-cause conditions in both all ages and children under five also fell significantly by >30%. Similar decreases in the main malaria indicators were observed in the three epidemiological strata (coastal, forest, savannah). All-cause admissions increased significantly in patients covered by the National Health Insurance Scheme (NHIS) compared to the non-insured. The non-malaria cases and non-malaria deaths increased or remained unchanged during the same period. All-cause mortality for children under 5 years old in household surveys, similar to those observed in the hospitals, declined by 43% between 2008 and 2014. The data provide compelling evidence of impact following LLIN mass campaigns targeting all ages since 2011, while maintaining other anti-malarial interventions. Malaria cases and deaths decreased by over 50 and 65%, respectively. The declines were stronger in children under five. Test positivity rate in all ages decreased by >40%. The decrease in malaria deaths was against a backdrop of increased admissions owing to free access to hospitalization through the NHIS. The study demonstrated that retrospective health facility-based data minimize reporting biases to assess effect of interventions. Malaria control in Ghana is dependent on sustained coverage of effective interventions and strengthened surveillance is vital to monitor progress of these investments.

Distribution and abundance of forest birds in low-altitude habitat on Hawai'i Island: Evidence for range expansion of native species

USGS Publications Warehouse

Spiegel, C.S.; Hart, P.J.; Woodwort, B.L.; Tweed, E.J.; Leburn, J.J.

2006-01-01

The Hawaiian honeycreepers are thought to be limited primarily to middle- and high-altitude wet forests due to anthropogenic factors at lower altitudes, especially introduced mosquitotransmitted avian malaria. However, recent research has demonstrated that at least one native species, the Hawai'i 'Amakihi (Hemignathus virens virens), is common in areas of active malaria transmission. We examined the current distribution and abundance of native and exotic forest birds within approximately 640 km2 of low-altitude (0-326 m) habitat on south-eastern Hawai'i Island, using roadside variable circular plot (VCP) at 174 stations along eight survey transects. We also re-surveyed 90 stations near sea level that were last surveyed in 1994-1995. Overall, introduced species were more abundant than natives; 11 exotic species made up 87% of the total individuals detected. The most common exotic passerines were Japanese White-eye (Zosterops japonicus), House Finch (Carpodacus mexicanus) and Northern Cardinal (Cardinalis cardinalis). Two native species, Hawai'i 'Amakihi and 'Apapane (Himatione sanguina), comprised 13% of the bird community at low altitudes. Hawai'i 'Amakihi were the most common and widespread native species, being found at 47% of stations at a density of 4.98 birds/ha (95% CI 3.52-7.03). Amakihi were significantly associated with 'ohi'a (Metrosideros polymorpha)-dominated forest. 'Apapane were more locally distributed, being found at only 10% of stations. Re-surveys of 1994-1995 transects demonstrated a significant increase in 'Amakihi abundance over the past decade. This work demonstrates a widespread recovery of Hawai'i 'Amakihi at low altitude in southeastern Hawai'i. The changing composition of the forest bird community at low-altitudes in Hawai'i has important implications for the dynamics of avian malaria in low-altitude Hawai'i, and for conservation of Hawai'i's lowland forests. ?? 2006 BirdLife International.

Malaria in Uganda: challenges to control on the long road to elimination. I. Epidemiology and current control efforts

PubMed Central

Yeka, Adoke; Gasasira, Anne; Mpimbaza, Arthur; Achan, Jane; Nankabirwa, Joaniter; Nsobya, Sam; Staedke, Sarah G.; Donnelly, Martin J.; Wabwire-Mangen, Fred; Talisuna, Ambrose; Dorsey, Grant; Kamya, Moses R.; Rosenthal, Philip J.

2011-01-01

Malaria remains one of the leading health problems of the developing world, and Uganda bears a particularly large burden from the disease. Our understanding is limited by a lack of reliable data, but it is clear that the prevalence of malaria infection, incidence of disease, and mortality from severe malaria all remain very high. Uganda has made progress in implementing key malaria control measures, in particular distribution of insecticide impregnated bednets, indoor residual spraying of insecticides, utilization of artemisinin-based combination therapy to treat uncomplicated malaria, and provision of intermittent preventive therapy for pregnant women. However, despite enthusiasm regarding the potential for the elimination of malaria in other areas, there is no convincing evidence that the burden of malaria has decreased in Uganda in recent years. Major challenges to malaria control in Uganda include very high malaria transmission intensity, inadequate health care resources, a weak health system, inadequate understanding of malaria epidemiology and the impact of control interventions, increasing resistance of parasites to drugs and of mosquitoes to insecticides, inappropriate case management, inadequate utilization of drugs to prevent malaria, and inadequate epidemic preparedness and response. Despite these challenges, prospects for the control of malaria have improved, and with attention to underlying challenges, progress toward the control of malaria in Uganda can be expected. PMID:21420377

High prevalence of asymptomatic malaria in south-eastern Bangladesh

PubMed Central

2014-01-01

Background The WHO has reported that RDT and microscopy-confirmed malaria cases have declined in recent years. However, it is still unclear if this reflects a real decrease in incidence in Bangladesh, as particularly the hilly and forested areas of the Chittagong Hill Tract (CHT) Districts report more than 80% of all cases and deaths. surveillance and epidemiological data on malaria from the CHT are limited; existing data report Plasmodium falciparum and Plasmodium vivax as the dominant species. Methods A cross-sectional survey was conducted in the District of Bandarban, the southernmost of the three Hill Tracts Districts, to collect district-wide malaria prevalence data from one of the regions with the highest malaria endemicity in Bangladesh. A multistage cluster sampling technique was used to collect blood samples from febrile and afebrile participants and malaria microscopy and standardized nested PCR for diagnosis were performed. Demographic data, vital signs and splenomegaly were recorded. Results Malaria prevalence across all subdistricts in the monsoon season was 30.7% (95% CI: 28.3-33.2) and 14.2% (95% CI: 12.5-16.2) by PCR and microscopy, respectively. Plasmodium falciparum mono-infections accounted for 58.9%, P. vivax mono-infections for 13.6%, Plasmodium malariae for 1.8%, and Plasmodium ovale for 1.4% of all positive cases. In 24.4% of all cases mixed infections were identified by PCR. The proportion of asymptomatic infections among PCR-confirmed cases was 77.0%, oligosymptomatic and symptomatic cases accounted for only 19.8 and 3.2%, respectively. Significantly (p < 0.01) more asymptomatic cases were recorded among participants older than 15 years as compared to younger participants, whereas prevalence and parasite density were significantly (p < 0.01) higher in patients younger than 15 years. Spleen rate and malaria prevalence in two to nine year olds were 18.6 and 34.6%, respectively. No significant difference in malaria prevalence and parasite density was observed between dry and rainy season. Conclusions A large proportion of asymptomatic plasmodial infections was found which likely act as a reservoir of transmission. This has major implications for ongoing malaria control programmes that are based on the treatment of symptomatic patients. These findings highlight the need for new intervention strategies targeting asymptomatic carriers. PMID:24406220

Cost effective malaria risk control using remote sensing and environmental data

NASA Astrophysics Data System (ADS)

Rahman, Md. Z.; Roytman, Leonid; Kadik, Abdel Hamid

2012-06-01

Malaria transmission in many part of the world specifically in Bangladesh and southern African countries is unstable and epidemic. An estimate of over a million cases is reported annually. Malaria is heterogeneous, potentially due to variations in ecological settings, socio-economic status, land cover, and agricultural practices. Malaria control only relies on treatment and supply of bed networks. Drug resistance to these diseases is widespread. Vector control is minimal. Malaria control in those countries faces many formidable challenges such as inadequate accessibility to effective treatment, lack of trained manpower, inaccessibility of endemic areas, poverty, lack of education, poor health infrastructure and low health budgets. Health facilities for malaria management are limited, surveillance is inadequate, and vector control is insufficient. Control can only be successful if the right methods are used at the right time in the right place. This paper aims to improve malaria control by developing malaria risk maps and risk models using satellite remote sensing data by identifying, assessing, and mapping determinants of malaria associated with environmental, socio-economic, malaria control, and agricultural factors.

Economic burden of malaria on businesses in Ghana: a case for private sector investment in malaria control.

PubMed

Nonvignon, Justice; Aryeetey, Genevieve Cecilia; Malm, Keziah L; Agyemang, Samuel Agyei; Aubyn, Vivian N A; Peprah, Nana Yaw; Bart-Plange, Constance N; Aikins, Moses

2016-09-06

Despite the significant gains made globally in reducing the burden of malaria, the disease remains a major public health challenge, especially in sub-Saharan Africa (SSA) including Ghana. There is a significant gap in financing malaria control globally. The private sector could become a significant source of financing malaria control. To get the private sector to appreciate the need to invest in malaria control, it is important to provide evidence of the economic burden of malaria on businesses. The objective of this study, therefore, was to estimate the economic burden on malaria on businesses in Ghana, so as to stimulate the sector's investment in malaria control. Data covering 2012-2014 were collected from 62 businesses sampled from Greater Accra, Ashanti and Western Regions of Ghana, which have the highest concentration of businesses in the country. Data on the cost of businesses' spending on treatment and prevention of malaria in staff and their dependants as well as staff absenteeism due to malaria and expenditure on other health-related activities were collected. Views of business leaders on the effect of malaria on their businesses were also compiled. The analysis was extrapolated to cover 5828 businesses across the country. The results show that businesses in Ghana lost about US$6.58 million to malaria in 2014, 90 % of which were direct costs. A total of 3913 workdays were lost due to malaria in firms in the study sample during the period 2012-2014. Businesses in the study sample spent an average of 0.5 % of the annual corporate returns on treatment of malaria in employees and their dependants, 0.3 % on malaria prevention, and 0.5 % on other health-related corporate social responsibilities. Again business leaders affirmed that malaria affects their businesses' efficiency, employee attendance and productivity and expenses. Finally, about 93 % of business leaders expressed the need private sector investment in malaria control. The economic burden of malaria on businesses in Ghana cannot be underestimated. This, together with business leaders' acknowledgement that it is important for private sector investment in malaria control, provides motivation for engagement of the private sector in financing malaria control activities.

Sustainable malaria control: transdisciplinary approaches for translational applications

PubMed Central

2012-01-01

With the adoption of the Global Malaria Action Plan, several countries are moving from malaria control towards elimination and eradication. However, the sustainability of some of the approaches taken may be questionable. Here, an overview of malaria control and elimination strategies is provided and the sustainability of each in context of vector- and parasite control is assessed. From this, it can be concluded that transdisciplinary approaches are essential for sustained malaria control and elimination in malaria-endemic communities. PMID:23268712

[Current status of malaria control knowledge awareness of primary and sec- ondary school students in Xuzhou City].

PubMed

Sun, Xing-sheng; Li, Li; Zhang, Kan-kan

2015-12-01

To understand the current status of malaria control knowledge awareness of primary and secondary school students and its influencing factors in Yunlong District, Xuzhou City, so as to provide the evidence for improving the malaria prevention work. A total of 800 students from 4 urban and rural primary and secondary schools were randomly selected and investigated with questionnaires. The total awareness rate of malaria control knowledge was 61.27%, and the awareness rates of symptoms of malaria and malaria prevention were only 38.99% and 57.59% respectively. The main approach of obtaining the malaria control knowledge was media (51.52%). The univariate analysis showed that sex, area and different education levels affected the awareness rates of malaria control knowledge (P < 0.05), and the Logistic analysis showed that the awareness rate of malaria control knowledge of country students was lower than that of urban students (P < 0.05), and the awareness rate of malaria control knowledge of the secondary school students was higher than that of the primary school students (P < 0.05). The awareness rate of malaria control knowledge of primary and secondary school students in Yunlong District is lower than that required by the national standard. Therefore, the health education of malaria control should be strengthened, especially in countryside school students and primary school students.

Initiating malaria control programs in the third world: directives for short- and long-term solutions.

PubMed

Basu, Sanjay

2002-01-01

Although malaria is a growing problem affecting several hundred million people each year, many malarial countries lack successful disease control programs. Worldwide malaria incidence rates are dramatically increasing, generating fear among many people who are witnessing malaria control initiatives fail. In this paper, we explore two options for malaria control in poor countries: (1) the production and distribution of a malaria vaccine and (2) the control of mosquitoes that harbor the malaria parasite. We first demonstrate that the development of a malaria vaccine is indeed likely, although it will take several years to produce because of both biological obstacles and insufficient research support. The distribution of such a vaccine, as suggested by some economists, will require that wealthy states promise a market to pharmaceutical companies who have traditionally failed to investigate diseases affecting the poorest of nations. But prior to the development of a malaria vaccine, we recommend the implementation of vector control pro- grams, such as those using Bti toxin, in regions with low vector capacity. Our analysis indicates that both endogenous programs in malarial regions and molecular approaches to parasite control will provide pragmatic solutions to the malaria problem. But the successful control of malaria will require sustained support from wealthy nations, without whom vaccine development and vector control programs will likely fail.

[Spatial epidemiological study on malaria epidemics in Hainan province].

PubMed

Wen, Liang; Shi, Run-He; Fang, Li-Qun; Xu, De-Zhong; Li, Cheng-Yi; Wang, Yong; Yuan, Zheng-Quan; Zhang, Hui

2008-06-01

To better understand the characteristics of spatial distribution of malaria epidemics in Hainan province and to explore the relationship between malaria epidemics and environmental factors, as well to develop prediction model on malaria epidemics. Data on Malaria and meteorological factors were collected in all 19 counties in Hainan province from May to Oct., 2000, and the proportion of land use types of these counties in this period were extracted from digital map of land use in Hainan province. Land surface temperatures (LST) were extracted from MODIS images and elevations of these counties were extracted from DEM of Hainan province. The coefficients of correlation of malaria incidences and these environmental factors were then calculated with SPSS 13.0, and negative binomial regression analysis were done using SAS 9.0. The incidence of malaria showed (1) positive correlations to elevation, proportion of forest land area and grassland area; (2) negative correlations to the proportion of cultivated area, urban and rural residents and to industrial enterprise area, LST; (3) no correlations to meteorological factors, proportion of water area, and unemployed land area. The prediction model of malaria which came from negative binomial regression analysis was: I (monthly, unit: 1/1,000,000) = exp (-1.672-0.399xLST). Spatial distribution of malaria epidemics was associated with some environmental factors, and prediction model of malaria epidemic could be developed with indexes which extracted from satellite remote sensing images.

How well are malaria maps used to design and finance malaria control in Africa?

PubMed

Omumbo, Judy A; Noor, Abdisalan M; Fall, Ibrahima S; Snow, Robert W

2013-01-01

Rational decision making on malaria control depends on an understanding of the epidemiological risks and control measures. National Malaria Control Programmes across Africa have access to a range of state-of-the-art malaria risk mapping products that might serve their decision-making needs. The use of cartography in planning malaria control has never been methodically reviewed. An audit of the risk maps used by NMCPs in 47 malaria endemic countries in Africa was undertaken by examining the most recent national malaria strategies, monitoring and evaluation plans, malaria programme reviews and applications submitted to the Global Fund. The types of maps presented and how they have been used to define priorities for investment and control was investigated. 91% of endemic countries in Africa have defined malaria risk at sub-national levels using at least one risk map. The range of risk maps varies from maps based on suitability of climate for transmission; predicted malaria seasons and temperature/altitude limitations, to representations of clinical data and modelled parasite prevalence. The choice of maps is influenced by the source of the information. Maps developed using national data through in-country research partnerships have greater utility than more readily accessible web-based options developed without inputs from national control programmes. Although almost all countries have stratification maps, only a few use them to guide decisions on the selection of interventions allocation of resources for malaria control. The way information on the epidemiology of malaria is presented and used needs to be addressed to ensure evidence-based added value in planning control. The science on modelled impact of interventions must be integrated into new mapping products to allow a translation of risk into rational decision making for malaria control. As overseas and domestic funding diminishes, strategic planning will be necessary to guide appropriate financing for malaria control.

A historical perspective on malaria control in Brazil

PubMed Central

Griffing, Sean Michael; Tauil, Pedro Luiz; Udhayakumar, Venkatachalam; Silva-Flannery, Luciana

2015-01-01

Malaria has always been an important public health problem in Brazil. The early history of Brazilian malaria and its control was powered by colonisation by Europeans and the forced relocation of Africans as slaves. Internal migration brought malaria to many regions in Brazil where, given suitableAnopheles mosquito vectors, it thrived. Almost from the start, officials recognised the problem malaria presented to economic development, but early control efforts were hampered by still developing public health control and ignorance of the underlying biology and ecology of malaria. Multiple regional and national malaria control efforts have been attempted with varying success. At present, the Amazon Basin accounts for 99% of Brazil’s reported malaria cases with regional increases in incidence often associated with large scale public works or migration. Here, we provide an exhaustive summary of primary literature in English, Spanish and Portuguese regarding Brazilian malaria control. Our goal was not to interpret the history of Brazilian malaria control from a particular political or theoretical perspective, but rather to provide a straightforward, chronological narrative of the events that have transpired in Brazil over the past 200 years and identify common themes. PMID:26517649

Zoonotic Malaria – Global Overview and Research and Policy Needs

PubMed Central

Ramasamy, Ranjan

2014-01-01

The four main Plasmodium species that cause human malaria, Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, and Plasmodium ovale, are transmitted between humans by mosquito vectors belonging to the genus Anopheles. It has recently become evident that Plasmodium knowlesi, a parasite that typically infects forest macaque monkeys, can be transmitted by anophelines to cause malaria in humans in Southeast Asia. Plasmodium knowlesi infections are frequently misdiagnosed microscopically as P. malariae. Direct human to human transmission of P. knowlesi by anophelines has not yet been established to occur in nature. Knowlesi malaria must therefore be presently considered a zoonotic disease. Polymerase chain reaction is now the definitive method for differentiating P. knowlesi from P. malariae and other human malaria parasites. The origin of P. falciparum and P. vivax in African apes are examples of ancient zoonoses that may be continuing at the present time with at least P. vivax, and possibly P. malariae and P. ovale. Other non-human primate malaria species, e.g., Plasmodium cynomolgi in Southeast Asia and Plasmodium brasilianum and Plasmodium simium in South America, can be transmitted to humans by mosquito vectors further emphasizing the potential for continuing zoonoses. The potential for zoonosis is influenced by human habitation and behavior as well as the adaptive capabilities of parasites and vectors. There is insufficient knowledge of the bionomics of Anopheles vector populations relevant to the cross-species transfer of malaria parasites and the real extent of malaria zoonoses. Appropriate strategies, based on more research, need to be developed for the prevention, diagnosis, and treatment of zoonotic malaria. PMID:25184118

Discourse on malaria elimination: where do forcibly displaced persons fit in these discussions?

PubMed Central

2013-01-01

Background Individuals forcibly displaced are some of the poorest people in the world, living in areas where infrastructure and services are at a bare minimum. Out of a total of 10,549,686 refugees protected and assisted by the United Nations High Commissioner for Refugees globally, 6,917,496 (65.6%) live in areas where malaria is transmitted. Historically, national malaria control programmes have excluded displaced populations. Results The current discourse on malaria elimination rarely includes discussion of forcibly displaced persons who reside within malaria-eliminating countries. Of the 100 malaria-endemic countries, 64 are controlling malaria and 36 are in some stage of elimination. Of these, 30 malaria-controlling countries and 13 countries in some phase of elimination host displaced populations of ≥50,000, even though 13 of the 36 (36.1%) malaria-elimination countries host displaced populations of ≥50,000 people. Discussion Now is the time for the malaria community to incorporate forcibly displaced populations residing within malarious areas into malaria control activities. Beneficiaries, whether they are internally displaced persons or refugees, should be viewed as partners in the delivery of malaria interventions and not simply as recipients. Conclusion Until equitable and sustainable malaria control includes everyone residing in an endemic area, the goal of malaria elimination will not be met. PMID:23575209

Larval habitat for the avian malaria vector culex quinquefasciatus (Diptera: Culicidae) in altered mid-elevation mesic-dry forests in Hawai'i

USGS Publications Warehouse

Reiter, M.E.; Lapointe, D.A.

2009-01-01

Effective management of avian malaria (Plasmodium relictum) in Hawai'i's endemic honeycreepers (Drepanidinae) requires the identification and subsequent reduction or treatment of larval habitat for the mosquito vector, Culex quinquefasciatus (Diptera: Culicidae). We conducted ground surveys, treehole surveys, and helicopter aerial surveys from 20012003 to identify all potential larval mosquito habitat within two 100+ ha mesic-dry forest study sites in Hawai'i Volcanoes National Park, Hawai'i; 'Ainahou Ranch and Mauna Loa Strip Road. At 'Ainahou Ranch, anthropogenic sites (43%) were more likely to contain mosquitoes than naturally occurring (8%) sites. Larvae of Cx. quinquefasciatus were predominately found in anthropogenic sites while Aedes albopictus larvae occurred less frequently in both anthropogenic sites and naturally-occurring sites. Additionally, moderate-size (???20-22,000 liters) anthropogenic potential larval habitat had >50% probability of mosquito presence compared to larger- and smaller-volume habitat (<50%). Less than 20% of trees surveyed at ' Ainahou Ranch had treeholes and few mosquito larvae were detected. Aerial surveys at 'Ainahou Ranch detected 56% (95% CI: 42-68%) of the potential larval habitat identified in ground surveys. At Mauna Loa Strip Road, Cx. quinquefasciatus larvae were only found in the rock holes of small intermittent stream drainages that made up 20% (5 of 25) of the total potential larval habitat. The volume of the potential larval habitat did not influence the probability of mosquito occurrence at Mauna Loa Strip Road. Our results suggest that Cx. quinquefasciatus abundance, and subsequently avian malaria, may be controlled by larval habitat reduction in the mesic-dry landscapes of Hawai'i where anthropogenic sources predominate.

Ethnography of a parasite: A quantitative ethnographic observation of forest malaria in the Amazon basin.

PubMed

Feged-Rivadeneira, Alejandro; Evans, Sian

2018-05-01

Malaria in the Amazon basin is persistently more prevalent among low density populations (1-4 people/[Formula: see text]). Describing malaria transmission in small populations, such as ethnic minorities in the Amazon basin, living in reserves in groups that amount to 110-450 individuals, is fundamental for the implementation of adequate interventions. Here, we examine malaria transmission in a context of high prevalence in a small population of Nükak ethnicity (ethnic group [Formula: see text] individuals, study group, [Formula: see text] individuals) living in the peri-urban area of a city with [Formula: see text] inhabitants in the Amazon basin. Using methods from behavioral ecology, we conducted a quantitative ethnography and collected data to inform of individual behavioral profiles. Individual malarial infection reports were available from the local public health offices, so each behavioral profile was associated with an epidemic profile for the past 5 years. Our research shows that, in-line with current opinion, malaria among the Nükak is not associated with an occupational hazard risk and follows a holoendemic pattern, where children are most susceptible to the parasite. Parasite loads of malarial infection among the Nükak persist at much higher rates than in any other neighboring ethnicity, which indicates an association between high incidence rates and endemicity. We hypothesize that malarial infection in the forest follows a pattern where the parasite persists in pockets of holoendemicity, and occupational hazard risk for individuals outside those pockets is associated with behaviors that take place in the proximity of the pockets of endemicity.

Changes in the burden of malaria following scale up of malaria control interventions in Mutasa District, Zimbabwe.

PubMed

Mharakurwa, Sungano; Mutambu, Susan L; Mberikunashe, Joseph; Thuma, Philip E; Moss, William J; Mason, Peter R

2013-07-01

To better understand trends in the burden of malaria and their temporal relationship to control activities, a survey was conducted to assess reported cases of malaria and malaria control activities in Mutasa District, Zimbabwe. Data on reported malaria cases were abstracted from available records at all three district hospitals, three rural hospitals and 25 rural health clinics in Mutasa District from 2003 to 2011. Malaria control interventions were scaled up through the support of the Roll Back Malaria Partnership, the Global Fund to Fight AIDS, Tuberculosis and Malaria, and The President's Malaria Initiative. The recommended first-line treatment regimen changed from chloroquine or a combination of chloroquine plus sulphadoxine/pyrimethamine to artemisinin-based combination therapy, the latter adopted by 70%, 95% and 100% of health clinics by 2008, 2009 and 2010, respectively. Diagnostic capacity improved, with rapid diagnostic tests (RDTs) available in all health clinics by 2008. Vector control consisted of indoor residual spraying and distribution of long-lasting insecticidal nets. The number of reported malaria cases initially increased from levels in 2003 to a peak in 2008 but then declined 39% from 2008 to 2010. The proportion of suspected cases of malaria in older children and adults remained high, ranging from 75% to 80%. From 2008 to 2010, the number of RDT positive cases of malaria decreased 35% but the decrease was greater for children younger than five years of age (60%) compared to older children and adults (26%). The burden of malaria in Mutasa District decreased following the scale up of malaria control interventions. However, the persistent high number of cases in older children and adults highlights the need for strategies to identify locally effective control measures that target all age groups.

Strengthening the policy setting process for global malaria control and elimination.

PubMed

D'Souza, Bianca J; Newman, Robert D

2012-01-27

The scale-up of malaria control efforts in recent years, coupled with major investments in malaria research, has produced impressive public health impact in a number of countries and has led to the development of new tools and strategies aimed at further consolidating malaria control goals. As a result, there is a growing need for the malaria policy setting process to rapidly review increasing amounts of evidence. The World Health Organization Global Malaria Programme, in keeping with its mandate to set evidence-informed policies for malaria control, has convened the Malaria Policy Advisory Committee as a mechanism to increase the timeliness, transparency, independence and relevance of its recommendations to World Health Organization member states in relation to malaria control and elimination. The Malaria Policy Advisory Committee, composed of 15 world-renowned malaria experts, will meet in full twice a year, with the inaugural meeting scheduled for 31 January to 2 February 2012 in Geneva. Policy recommendations, and the evidence to support them, will be published within two months of every meeting as part of an open access Malaria Journal thematic series. This article is a prelude to that series and provides the global malaria community with the background and overview of the Committee and its terms of reference.

The complexities of malaria disease manifestations with a focus on asymptomatic malaria

PubMed Central

2012-01-01

Malaria is a serious parasitic disease in the developing world, causing high morbidity and mortality. The pathogenesis of malaria is complex, and the clinical presentation of disease ranges from severe and complicated, to mild and uncomplicated, to asymptomatic malaria. Despite a wealth of studies on the clinical severity of disease, asymptomatic malaria infections are still poorly understood. Asymptomatic malaria remains a challenge for malaria control programs as it significantly influences transmission dynamics. A thorough understanding of the interaction between hosts and parasites in the development of different clinical outcomes is required. In this review, the problems and obstacles to the study and control of asymptomatic malaria are discussed. The human and parasite factors associated with differential clinical outcomes are described and the management and treatment strategies for the control of the disease are outlined. Further, the crucial gaps in the knowledge of asymptomatic malaria that should be the focus of future research towards development of more effective malaria control strategies are highlighted. PMID:22289302

Earth observation in support of malaria control and epidemiology: MALAREO monitoring approaches.

PubMed

Franke, Jonas; Gebreslasie, Michael; Bauwens, Ides; Deleu, Julie; Siegert, Florian

2015-06-03

Malaria affects about half of the world's population, with the vast majority of cases occuring in Africa. National malaria control programmes aim to reduce the burden of malaria and its negative, socioeconomic effects by using various control strategies (e.g. vector control, environmental management and case tracking). Vector control is the most effective transmission prevention strategy, while environmental factors are the key parameters affecting transmission. Geographic information systems (GIS), earth observation (EO) and spatial modelling are increasingly being recognised as valuable tools for effective management and malaria vector control. Issues previously inhibiting the use of EO in epidemiology and malaria control such as poor satellite sensor performance, high costs and long turnaround times, have since been resolved through modern technology. The core goal of this study was to develop and implement the capabilities of EO data for national malaria control programmes in South Africa, Swaziland and Mozambique. High- and very high resolution (HR and VHR) land cover and wetland maps were generated for the identification of potential vector habitats and human activities, as well as geoinformation on distance to wetlands for malaria risk modelling, population density maps, habitat foci maps and VHR household maps. These products were further used for modelling malaria incidence and the analysis of environmental factors that favour vector breeding. Geoproducts were also transferred to the staff of national malaria control programmes in seven African countries to demonstrate how EO data and GIS can support vector control strategy planning and monitoring. The transferred EO products support better epidemiological understanding of environmental factors related to malaria transmission, and allow for spatio-temporal targeting of malaria control interventions, thereby improving the cost-effectiveness of interventions.

Optimal insecticide-treated bed-net coverage and malaria treatment in a malaria-HIV co-infection model.

PubMed

Mohammed-Awel, Jemal; Numfor, Eric

2017-03-01

We propose and study a mathematical model for malaria-HIV co-infection transmission and control, in which malaria treatment and insecticide-treated nets are incorporated. The existence of a backward bifurcation is established analytically, and the occurrence of such backward bifurcation is influenced by disease-induced mortality, insecticide-treated bed-net coverage and malaria treatment parameters. To further assess the impact of malaria treatment and insecticide-treated bed-net coverage, we formulate an optimal control problem with malaria treatment and insecticide-treated nets as control functions. Using reasonable parameter values, numerical simulations of the optimal control suggest the possibility of eliminating malaria and reducing HIV prevalence significantly, within a short time horizon.

Lessons on malaria control in the ethnic minority regions in Northern Myanmar along the China border, 2007-2014.

PubMed

Wang, Ru-Bo; Dong, Jia-Qiang; Xia, Zhi-Gui; Cai, Tao; Zhang, Qing-Feng; Zhang, Yao; Tian, Yang-Hui; Sun, Xiao-Ying; Zhang, Guang-Yun; Li, Qing-Pu; Xu, Xiao-Yu; Li, Jia-Yin; Zhang, Jun

2016-10-06

For many countries where malaria is endemic, the burden of malaria is high in border regions. In ethnic minority areas along the Myanmar-China border, residents have poor access to medical care for diagnosis and treatment, and there have been many malaria outbreaks in such areas. Since 2007, with the support of the Global Fund to Fight AIDS, Tuberculosis and Malaria (GFATM), a malaria control project was introduced to reduce the malaria burden in several ethnic minority regions. A malaria control network was established during the period from 2007 to 2014. Multiple malaria interventions, including diagnosis, treatment, distribution of LLINs and health education, were conducted to improve the accessibility and quality of malaria control services for local residents. Annual cross-sectional surveys were conducted to evaluate intervention coverage and indicators of malaria transmission. In ethnic minority regions where a malaria control network was established, both the annual malaria incidence (19.1 per thousand per year, in 2009; 8.7, in 2014) and malaria prevalence (13.6 % in 2008; 0.43 % in 2014) decreased dramatically during the past 5-6 years. A total of 851 393 febrile patients were detected, 202 598 malaria cases (including confirmed cases and suspected cases) were treated, and 759 574 LLINs were delivered to populations at risk. Of households in 2012, 73.9 % had at least one ITNs/LLINs (vs. 28.3 %, in 2008), and 50.7 % of children less than 5 years and 50.3 % of pregnant women slept under LLINs the night prior to their visit. Additionally, malaria knowledge was improved in 68.4 % of residents. There has been great success in improving malaria control in these regions from 2007 to 2014. Malaria burdens have decreased, especially in KOK and WA. The continued maintenance of sustainable malaria control networks in these regions may be a long-term process, due to regional conflicts and the lack of funds, technology, and health workers. Furthermore, information and scientific support from the international community should be offered to these ethnic minority regions to uphold recent achievements.

Predicting Malaria occurrence in Southwest and North central Nigeria using Meteorological parameters

NASA Astrophysics Data System (ADS)

Akinbobola, A.; Omotosho, J. Bayo

2013-09-01

Malaria is a major public health problem especially in the tropics with the potential to significantly increase in response to changing weather and climate. This study explored the impact of weather and climate and its variability on the occurrence and transmission of malaria in Akure, the tropical rain forest area of southwest and Kaduna, in the savanna area of Nigeria. We investigate this supposition by looking at the relationship between rainfall, relative humidity, minimum and maximum temperature, and malaria at the two stations. This study uses monthly data of 7 years (2001-2007) for both meteorological data and record of reported cases of malaria infection. Autoregressive integrated moving average (ARIMA) models were used to evaluate the relationship between weather factors and malaria incidence. Of all the models tested, the ARIMA (1, 0, 1) model fits the malaria incidence data best for Akure and Kaduna according to normalized Bayesian information criterion (BIC) and goodness-of-fit criteria. Humidity and rainfall have almost the same trend of association in all the stations while maximum temperature share the same negative association at southwestern stations and positive in the northern station. Rainfall and humidity have a positive association with malaria incidence at lag of 1 month. In all, we found that minimum temperature is not a limiting factor for malaria transmission in Akure but otherwise in the other stations.

Seasonal Distribution, Biology, and Human Attraction Patterns of Mosquitoes (Diptera: Culicidae) in a Rural Village and Adjacent Forested Site Near Iquitos, Peru

DTIC Science & Technology

2008-11-01

and malarial activity in the Amazon Basin, Loreto Department, Peru , to determine the relative abundance, species diversity, and seasonal and vertical...populations. KEY WORDS Anopheles, bionomics, mosquito ecology, Amazon Basin, Peru Malaria and other arthropod-vectored diseases are on the increase...in the Amazon Basin region of Peru to date. The Puerto Almendra area was selected because human cases of dengue, malaria, Mayaro, Oropouche

Microsatellite primers for Culex pipiens quinquefasciatus, the vector of avian malaria in Hawaii

USGS Publications Warehouse

Fonseca, Dina M.; Atkinson, Carter T.; Fleischer, Robert C.

1998-01-01

The southern house mosquito, Culex pipiens quinquefasciatus (Diptera: Culicidae), was introduced accidentally to Hawaii in 1826 (van Riper et al. 1986). There it eventually became the vector of avian malaria, Plasmodium relictum, a disease that severely limits the size and distribution of endemic forest bird populations in Hawaii (Atkinson et al. 1995). Cx.p. quinquefasciatus has a circumtropical distribution and is also the vector for human diseases such as lymphatic filariasis and several encephalitis.

Habitat suitability and ecological niche profile of major malaria vectors in Cameroon

PubMed Central

2009-01-01

Background Suitability of environmental conditions determines a species distribution in space and time. Understanding and modelling the ecological niche of mosquito disease vectors can, therefore, be a powerful predictor of the risk of exposure to the pathogens they transmit. In Africa, five anophelines are responsible for over 95% of total malaria transmission. However, detailed knowledge of the geographic distribution and ecological requirements of these species is to date still inadequate. Methods Indoor-resting mosquitoes were sampled from 386 villages covering the full range of ecological settings available in Cameroon, Central Africa. Using a predictive species distribution modeling approach based only on presence records, habitat suitability maps were constructed for the five major malaria vectors Anopheles gambiae, Anopheles funestus, Anopheles arabiensis, Anopheles nili and Anopheles moucheti. The influence of 17 climatic, topographic, and land use variables on mosquito geographic distribution was assessed by multivariate regression and ordination techniques. Results Twenty-four anopheline species were collected, of which 17 are known to transmit malaria in Africa. Ecological Niche Factor Analysis, Habitat Suitability modeling and Canonical Correspondence Analysis revealed marked differences among the five major malaria vector species, both in terms of ecological requirements and niche breadth. Eco-geographical variables (EGVs) related to human activity had the highest impact on habitat suitability for the five major malaria vectors, with areas of low population density being of marginal or unsuitable habitat quality. Sunlight exposure, rainfall, evapo-transpiration, relative humidity, and wind speed were among the most discriminative EGVs separating "forest" from "savanna" species. Conclusions The distribution of major malaria vectors in Cameroon is strongly affected by the impact of humans on the environment, with variables related to proximity to human settings being among the best predictors of habitat suitability. The ecologically more tolerant species An. gambiae and An. funestus were recorded in a wide range of eco-climatic settings. The other three major vectors, An. arabiensis, An. moucheti, and An. nili, were more specialized. Ecological niche and species distribution modelling should help improve malaria vector control interventions by targeting places and times where the impact on vector populations and disease transmission can be optimized. PMID:20028559

Habitat suitability and ecological niche profile of major malaria vectors in Cameroon.

PubMed

Ayala, Diego; Costantini, Carlo; Ose, Kenji; Kamdem, Guy C; Antonio-Nkondjio, Christophe; Agbor, Jean-Pierre; Awono-Ambene, Parfait; Fontenille, Didier; Simard, Frédéric

2009-12-23

Suitability of environmental conditions determines a species distribution in space and time. Understanding and modelling the ecological niche of mosquito disease vectors can, therefore, be a powerful predictor of the risk of exposure to the pathogens they transmit. In Africa, five anophelines are responsible for over 95% of total malaria transmission. However, detailed knowledge of the geographic distribution and ecological requirements of these species is to date still inadequate. Indoor-resting mosquitoes were sampled from 386 villages covering the full range of ecological settings available in Cameroon, Central Africa. Using a predictive species distribution modeling approach based only on presence records, habitat suitability maps were constructed for the five major malaria vectors Anopheles gambiae, Anopheles funestus, Anopheles arabiensis, Anopheles nili and Anopheles moucheti. The influence of 17 climatic, topographic, and land use variables on mosquito geographic distribution was assessed by multivariate regression and ordination techniques. Twenty-four anopheline species were collected, of which 17 are known to transmit malaria in Africa. Ecological Niche Factor Analysis, Habitat Suitability modeling and Canonical Correspondence Analysis revealed marked differences among the five major malaria vector species, both in terms of ecological requirements and niche breadth. Eco-geographical variables (EGVs) related to human activity had the highest impact on habitat suitability for the five major malaria vectors, with areas of low population density being of marginal or unsuitable habitat quality. Sunlight exposure, rainfall, evapo-transpiration, relative humidity, and wind speed were among the most discriminative EGVs separating "forest" from "savanna" species. The distribution of major malaria vectors in Cameroon is strongly affected by the impact of humans on the environment, with variables related to proximity to human settings being among the best predictors of habitat suitability. The ecologically more tolerant species An. gambiae and An. funestus were recorded in a wide range of eco-climatic settings. The other three major vectors, An. arabiensis, An. moucheti, and An. nili, were more specialized. Ecological niche and species distribution modelling should help improve malaria vector control interventions by targeting places and times where the impact on vector populations and disease transmission can be optimized.

From malaria control to eradication: The WHO perspective.

PubMed

Mendis, Kamini; Rietveld, Aafje; Warsame, Marian; Bosman, Andrea; Greenwood, Brian; Wernsdorfer, Walther H

2009-07-01

Efforts to control malaria have been boosted in the past few years with increased international funding and greater political commitment. Consequently, the reported malaria burden is being reduced in a number of countries throughout the world, including in some countries in tropical Africa where the burden of malaria is greatest. These achievements have raised new hopes of eradicating malaria. This paper summarizes the outcomes of a World Health Organization's expert meeting on the feasibility of such a goal. Given the hindsight and experience of the Global Malaria Eradication Programme of the 1950s and 1960s, and current knowledge of the effectiveness of antimalarial tools and interventions, it would be feasible to effectively control malaria in all parts of the world and greatly reduce the enormous morbidity and mortality of malaria. It would also be entirely feasible to eliminate malaria from countries and regions where the intensity of transmission is low to moderate, and where health systems are strong. Elimination of malaria requires a re-orientation of control activity, moving away from a population-based coverage of interventions, to one based on a programme of effective surveillance and response. Sustained efforts will be required to prevent the resurgence of malaria from where it is eliminated. Eliminating malaria from countries where the intensity of transmission is high and stable such as in tropical Africa will require more potent tools and stronger health systems than are available today. When such countries have effectively reduced the burden of malaria, the achievements will need to be consolidated before a programme re-orientation towards malaria elimination is contemplated. Malaria control and elimination are under the constant threat of the parasite and vector mosquito developing resistance to medicines and insecticides, which are the cornerstones of current antimalarial interventions. The prospects of malaria eradication, therefore, rest heavily on the outcomes of research and development for new and improved tools. Malaria control and elimination are complementary objectives in the global fight against malaria.

Cost of malaria control in China: Henan's consolidation programme from community and government perspectives.

PubMed Central

Jackson, Sukhan; Sleigh, Adrian C.; Liu, Xi-Li

2002-01-01

OBJECTIVE: To assist with strategic planning for the eradication of malaria in Henan Province, China, which reached the consolidation phase of malaria control in 1992, when only 318 malaria cases were reported. METHODS: We conducted a prospective two-year study of the costs for Henan's malaria control programme. We used a cost model that could also be applied to other malaria programmes in mainland China, and analysed the cost of the three components of Henan's malaria programme: suspected malaria case management, vector surveillance, and population blood surveys. Primary cost data were collected from the government, and data on suspected malaria patients were collected in two malaria counties (population 2 093 100). We enlisted the help of 260 village doctors in six townships or former communes (population 247 762), and studied all 12 325 reported cases of suspected malaria in their catchment areas in 1994 and 1995. FINDINGS: The average annual government investment in malaria control was estimated to be US$ 111 516 (case-management 59%; active blood surveys 25%; vector surveillance 12%; and contingencies and special projects 4%). The average cost (direct and indirect) for patients seeking treatment for suspected malaria was US$ 3.48, equivalent to 10 days' income for rural residents. Each suspected malaria case cost the government an average of US$ 0.78. CONCLUSION: Further cuts in government funding will increase future costs when epidemic malaria returns; investment in malaria control should therefore continue at least at current levels of US$ 0.03 per person at risk. PMID:12219157

Ethical aspects of malaria control and research.

PubMed

Jamrozik, Euzebiusz; de la Fuente-Núñez, Vânia; Reis, Andreas; Ringwald, Pascal; Selgelid, Michael J

2015-12-22

Malaria currently causes more harm to human beings than any other parasitic disease, and disproportionally affects low-income populations. The ethical issues raised by efforts to control or eliminate malaria have received little explicit analysis, in comparison with other major diseases of poverty. While some ethical issues associated with malaria are similar to those that have been the subject of debate in the context of other infectious diseases, malaria also raises distinct ethical issues in virtue of its unique history, epidemiology, and biology. This paper provides preliminary ethical analyses of the especially salient issues of: (i) global health justice, (ii) universal access to malaria control initiatives, (iii) multidrug resistance, including artemisinin-based combination therapy (ACT) resistance, (iv) mandatory screening, (v) mass drug administration, (vi) benefits and risks of primaquine, and (vii) malaria in the context of blood donation and transfusion. Several ethical issues are also raised by past, present and future malaria research initiatives, in particular: (i) controlled infection studies, (ii) human landing catches, (iii) transmission-blocking vaccines, and (iv) genetically-modified mosquitoes. This article maps the terrain of these major ethical issues surrounding malaria control and elimination. Its objective is to motivate further research and discussion of ethical issues associated with malaria--and to assist health workers, researchers, and policy makers in pursuit of ethically sound malaria control practice and policy.

[Global trends in malaria control. Progress and topical tasks in malaria control programs].

PubMed

Kondrashin, A V; Baranova, A M; Morozova, L F; Stepanova, E V

2011-01-01

This communication is the first in the series consisting of two publications describing the present state of malaria control and elimination in the world. The global malaria situation in 2009-2010 demonstrated a considerable situation as compared to the previous years. This improvement is associated with a considerable global increase of investments made by both national governments and world society to the malaria control programs. Spectacular progress has been achieved even in the areas of the most infection-affected African countries situated to the south of the Sahara Desert. It has been estimated that malaria cases in the world declined from 233, 000,000 in 2000 to 225,000,000 in 2009. Malaria mortality decreased from 985,000 in 2000 to 781,000 in 2009. To maintain the results achieved and to further reduce the problem of malaria worldwide, it is necessary to ensure a long-term political and financial support for malaria control programs at the national and international levels.

Enhancing the application of effective malaria interventions in Africa through training.

PubMed

Ijumba, Jasper N; Kitua, Andrew Y

2004-08-01

Africa bears more than 90% of the entire global malaria disease burden. Surprisingly, even with the current renewed interest in malaria prevention and control and the enabling environment resulting from the Roll Back Malaria initiative and the political commitment made by the African Presidents at the Abuja Summit, there are still no significant initiatives for strengthening capacity for malaria control through training within the African continent itself. The Center for Enhancement of Effective Malaria Interventions (CEEMI) has been established in Dar es Salaam, Tanzania for results-oriented training. It is intended to provide the needed skills for identifying and solving malaria control problems and providing incentives to malaria control workers in their work performance. The intention is to produce implementers with leadership skills for planning and managing malaria control activities and who can use strategic thinking in improving their work performance. To sustain political commitment and support and to sensitize the community on malaria issues, the CEEMI, in collaboration with the Ministry of Health (National Malaria Control Program), the Institute of Journalism and Mass Communication of the University of Dar es Salaam, and the Commonwealth Broadcasting Association have already conducted malaria seminars for Tanzanian Members of Parliament and journalists from Kenya, Malawi, Tanzania, and Uganda. Additionally, a diploma course in health communication is being developed for journalists and for the same purpose. Also being developed is a training module for "Council Malaria Focal Person." This is aimed at complementing the Roll Back Malaria initiative to meet the Abuja targets of reducing morbidity and mortality due to malaria by 50% by 2010. Copyright 2004 The American Society of Tropical Medicine and Hygiene

Malaria Distribution, Prevalence, Drug Resistance and Control in Indonesia

PubMed Central

Elyazar, Iqbal R.F.; Hay, Simon I.; Baird, J. Kevin

2011-01-01

Approximately 230 million people live in Indonesia. The country is also home to over 20 anopheline vectors of malaria which transmit all four of the species of Plasmodium that routinely infect humans. A complex mosaic of risk of infection across this 5000-km-long archipelago of thousands of islands and distinctive habitats seriously challenges efforts to control malaria. Social, economic and political dimensions contribute to these complexities. This chapter examines malaria and its control in Indonesia, from the earliest efforts by malariologists of the colonial Netherlands East Indies, through the Global Malaria Eradication Campaign of the 1950s, the tumult following the coup d’état of 1965, the global resurgence of malaria through the 1980s and 1990s and finally through to the decentralization of government authority following the fall of the authoritarian Soeharto regime in 1998. We detail important methods of control and their impact in the context of the political systems that supported them. We examine prospects for malaria control in contemporary decentralized and democratized Indonesia with multidrug-resistant malaria and greatly diminished capacities for integrated malaria control management programs. PMID:21295677

[Investigation on knowledge of malaria prevention and control in residents of Suining County].

PubMed

Tang, Yue-e

2014-08-01

To understand the status of knowledge of malaria prevention and control in residents of Suining County, so as to provide the reference for improving the implementation of malaria elimination. Nine villages in 3 townships (3 villages per township) were randomly selected as the study areas, and 200 residents aged above 15 years of each village were investigated with questionnaire for the knowledge of malaria prevention and control. The awareness rates of "malaria transmission way", main symptoms of malaria", "life-threatening of falciparum malaria", "how to treat malaria", and "how to prevent malaria" were 96.27%, 95.01%, 81.46%, 98.19% and 96.27%, respectively. There were no significant differences between the different genders and among the different areas (all P >0.05), but there were significant differences among different age groups (all P <0.05). The awareness of malaria prevention and control in residents of Suining County is relatively high, which means the health education is effective.

Perceived role and its enhancing factors among the village health volunteers regarding malaria control in rural myanmar.

PubMed

Aung, P Linn; Silawan, Tassanee; Rawiworrakul, Tassanee; Min, Myo

2018-01-01

Village health volunteers (VHVs) are key agents for malaria control in community. The Myanmar Medical Association-Malaria (MMA-Malaria) Project has promoted effective malaria control in endemic and high-risk townships by supporting roles of VHVs. To assess the roles of VHVs on malaria control and factors enhancing their roles in rural Myanmar. A cross-sectional study was conducted in five townships where the MMA-Malaria Project has been implemented. One hundred and fifty VHVs were sampled from five townships by simple random sampling. Data were collected by trained interviewers using structured questionnaires, which covered sociodemographic, supportive, motivational factors, and roles of malaria control. Studied variables were described by proportions, means, and standard deviations and were analyzed for their association by odds ratio with 95% confidence interval and Chi-square tests. Most of VHVs (96%) expected to demonstrate good roles on malaria control, but only 44.0% exhibited current roles at a good level. Factors enhancing their roles were female (P = 0.037), family income ≥50,001 kyat/month (P < 0.015), time serving as a volunteer 1-2 years (P = 0.006), good knowledge of malaria control (P < 0.001), good family support (P < 0.001), good community support (P < 0.001), and good motivational factors (P = 0.002). VHVs are key agents for malaria control in community. Most of VHVs expected to demonstrate good roles on malaria control, but less than half of them exhibited current roles at a good level. The systems and program for improving VHVs' knowledge, encouraging family and community support, and promoting motivation are essential for their better roles.

76 FR 13619 - Disease, Disability, and Injury Prevention and Control Special Emphasis Panel (SEP): Funding...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-14

... Institute Pasteur of Madagascar and the Centers for Disease Control and Prevention on Malaria and Vector... Malaria Prevention and Control in the Republic of Uganda as Part of the President's Malaria Initiative... Institute Pasteur of Madagascar and the Centers for Disease Control and Prevention on Malaria and Vector...

The economics of malaria control and elimination: a systematic review.

PubMed

Shretta, Rima; Avanceña, Anton L V; Hatefi, Arian

2016-12-12

Declining donor funding and competing health priorities threaten the sustainability of malaria programmes. Elucidating the cost and benefits of continued investments in malaria could encourage sustained political and financial commitments. The evidence, although available, remains disparate. This paper reviews the existing literature on the economic and financial cost and return of malaria control, elimination and eradication. A review of articles that were published on or before September 2014 on the cost and benefits of malaria control and elimination was performed. Studies were classified based on their scope and were analysed according to two major categories: cost of malaria control and elimination to a health system, and cost-benefit studies. Only studies involving more than two control or elimination interventions were included. Outcomes of interest were total programmatic cost, cost per capita, and benefit-cost ratios (BCRs). All costs were converted to 2013 US$ for standardization. Of the 6425 articles identified, 54 studies were included in this review. Twenty-two were focused on elimination or eradication while 32 focused on intensive control. Forty-eight per cent of studies included in this review were published on or after 2000. Overall, the annual per capita cost of malaria control to a health system ranged from $0.11 to $39.06 (median: $2.21) while that for malaria elimination ranged from $0.18 to $27 (median: $3.00). BCRs of investing in malaria control and elimination ranged from 2.4 to over 145. Overall, investments needed for malaria control and elimination varied greatly amongst the various countries and contexts. In most cases, the cost of elimination was greater than the cost of control. At the same time, the benefits of investing in malaria greatly outweighed the costs. While the cost of elimination in most cases was greater than the cost of control, the benefits greatly outweighed the cost. Information from this review provides guidance to national malaria programmes on the cost and benefits of malaria elimination in the absence of data. Importantly, the review highlights the need for more robust economic analyses using standard inputs and methods to strengthen the evidence needed for sustained financing for malaria elimination.

Knowledge, attitude, and practice about malaria: Socio-demographic implications for malaria control in rural Ghana.

PubMed

Assan, Abraham; Takian, Amirhossein; Hanafi-Bojd, Ahmad Ali; Rahimiforoushani, Abbas; Nematolahi, Shahrzad

2017-11-01

Despite continuing international attention to malaria prevention, the disease remains a global public health problem. We investigated socio-demographic factors influencing knowledge, attitudes, and practices about malaria in rural Ghana. Our survey looked at 354 households. Mean knowledge score was higher among individuals with a history of volunteers having visited their households to educate them about malaria; families with 4-6 members; and males. Households with at least one under-five-aged child also had significantly higher knowledge scores. Households with at least one pregnant woman evinced a positive attitude towards malaria prevention. National malaria control strategies have achieved positive results in the fight against malaria. Nonetheless, multipronged community-based health strategies that integrate malaria programs and population growth control initiatives may be able to reach by 2030 the sustainable development goal of eliminating malaria.

Integrated vector management for malaria control

PubMed Central

Beier, John C; Keating, Joseph; Githure, John I; Macdonald, Michael B; Impoinvil, Daniel E; Novak, Robert J

2008-01-01

Integrated vector management (IVM) is defined as "a rational decision-making process for the optimal use of resources for vector control" and includes five key elements: 1) evidence-based decision-making, 2) integrated approaches 3), collaboration within the health sector and with other sectors, 4) advocacy, social mobilization, and legislation, and 5) capacity-building. In 2004, the WHO adopted IVM globally for the control of all vector-borne diseases. Important recent progress has been made in developing and promoting IVM for national malaria control programmes in Africa at a time when successful malaria control programmes are scaling-up with insecticide-treated nets (ITN) and/or indoor residual spraying (IRS) coverage. While interventions using only ITNs and/or IRS successfully reduce transmission intensity and the burden of malaria in many situations, it is not clear if these interventions alone will achieve those critical low levels that result in malaria elimination. Despite the successful employment of comprehensive integrated malaria control programmes, further strengthening of vector control components through IVM is relevant, especially during the "end-game" where control is successful and further efforts are required to go from low transmission situations to sustained local and country-wide malaria elimination. To meet this need and to ensure sustainability of control efforts, malaria control programmes should strengthen their capacity to use data for decision-making with respect to evaluation of current vector control programmes, employment of additional vector control tools in conjunction with ITN/IRS tactics, case-detection and treatment strategies, and determine how much and what types of vector control and interdisciplinary input are required to achieve malaria elimination. Similarly, on a global scale, there is a need for continued research to identify and evaluate new tools for vector control that can be integrated with existing biomedical strategies within national malaria control programmes. This review provides an overview of how IVM programmes are being implemented, and provides recommendations for further development of IVM to meet the goals of national malaria control programmes in Africa. PMID:19091038

Distribution of the Habitat Suitability of the Main Malaria Vector in French Guiana Using Maximum Entropy Modeling.

PubMed

Moua, Yi; Roux, Emmanuel; Girod, Romain; Dusfour, Isabelle; de Thoisy, Benoit; Seyler, Frédérique; Briolant, Sébastien

2017-05-01

Malaria is an important health issue in French Guiana. Its principal mosquito vector in this region is Anopheles darlingi Root. Knowledge of the spatial distribution of this species is still very incomplete due to the extent of French Guiana and the difficulty to access most of the territory. Species distribution modeling based on the maximal entropy procedure was used to predict the spatial distribution of An. darlingi using 39 presence sites. The resulting model provided significantly high prediction performances (mean 10-fold cross-validated partial area under the curve and continuous Boyce index equal to, respectively, 1.11-with a level of omission error of 20%-and 0.42). The model also provided a habitat suitability map and environmental response curves in accordance with the known entomological situation. Several environmental characteristics that had a positive correlation with the presence of An. darlingi were highlighted: nonpermanent anthropogenic changes of the natural environment, the presence of roads and tracks, and opening of the forest. Some geomorphological landforms and high altitude landscapes appear to be unsuitable for An. darlingi. The species distribution modeling was able to reliably predict the distribution of suitable habitats for An. darlingi in French Guiana. Results allowed completion of the knowledge of the spatial distribution of the principal malaria vector in this Amazonian region, and identification of the main factors that favor its presence. They should contribute to the definition of a necessary targeted vector control strategy in a malaria pre-elimination stage, and allow extrapolation of the acquired knowledge to other Amazonian or malaria-endemic contexts. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Malaria resurgence: a systematic review and assessment of its causes

PubMed Central

2012-01-01

Background Considerable declines in malaria have accompanied increased funding for control since the year 2000, but historical failures to maintain gains against the disease underscore the fragility of these successes. Although malaria transmission can be suppressed by effective control measures, in the absence of active intervention malaria will return to an intrinsic equilibrium determined by factors related to ecology, efficiency of mosquito vectors, and socioeconomic characteristics. Understanding where and why resurgence has occurred historically can help current and future malaria control programmes avoid the mistakes of the past. Methods A systematic review of the literature was conducted to identify historical malaria resurgence events. All suggested causes of these events were categorized according to whether they were related to weakened malaria control programmes, increased potential for malaria transmission, or technical obstacles like resistance. Results The review identified 75 resurgence events in 61 countries, occurring from the 1930s through the 2000s. Almost all resurgence events (68/75 = 91%) were attributed at least in part to the weakening of malaria control programmes for a variety of reasons, of which resource constraints were the most common (39/68 = 57%). Over half of the events (44/75 = 59%) were attributed in part to increases in the intrinsic potential for malaria transmission, while only 24/75 (32%) were attributed to vector or drug resistance. Conclusions Given that most malaria resurgences have been linked to weakening of control programmes, there is an urgent need to develop practical solutions to the financial and operational threats to effectively sustaining today’s successful malaria control programmes. PMID:22531245

Using a geographical information system to plan a malaria control programme in South Africa.

PubMed Central

Booman, M.; Durrheim, D. N.; La Grange, K.; Martin, C.; Mabuza, A. M.; Zitha, A.; Mbokazi, F. M.; Fraser, C.; Sharp, B. L.

2000-01-01

INTRODUCTION: Sustainable control of malaria in sub-Saharan Africa is jeopardized by dwindling public health resources resulting from competing health priorities that include an overwhelming acquired immunodeficiency syndrome (AIDS) epidemic. In Mpumalanga province, South Africa, rational planning has historically been hampered by a case surveillance system for malaria that only provided estimates of risk at the magisterial district level (a subdivision of a province). METHODS: To better map control programme activities to their geographical location, the malaria notification system was overhauled and a geographical information system implemented. The introduction of a simplified notification form used only for malaria and a carefully monitored notification system provided the good quality data necessary to support an effective geographical information system. RESULTS: The geographical information system displays data on malaria cases at a village or town level and has proved valuable in stratifying malaria risk within those magisterial districts at highest risk, Barberton and Nkomazi. The conspicuous west-to-east gradient, in which the risk rises sharply towards the Mozambican border (relative risk = 4.12, 95% confidence interval = 3.88-4.46 when the malaria risk within 5 km of the border was compared with the remaining areas in these two districts), allowed development of a targeted approach to control. DISCUSSION: The geographical information system for malaria was enormously valuable in enabling malaria risk at town and village level to be shown. Matching malaria control measures to specific strata of endemic malaria has provided the opportunity for more efficient malaria control in Mpumalanga province. PMID:11196490

Avian disease and mosquito vectors in the Kahuku unit of Hawai`i Volcanoes National Park and Ka`u Forest Reserve

USGS Publications Warehouse

Gaudioso, Jacqueline; Lapointe, Dennis; Atkinson, Carter T.; Egan, Ariel N.

2015-01-01

While avian disease has been well-studied in windward forests of Hawai‘i Island, there have been few studies in leeward Ka‘u. We surveyed four altitudinal sites ranging from 1,200 to 2,200 m asl in the Kahuku Unit of Hawai‘i Volcanoes National Park (Kahuku) and three altitudinal sites ranging from 1,200 to 1,500 m asl in the Ka‘u Forest Reserve (Ka‘u) for the prevalence of avian disease and presence of mosquitoes. We collected blood samples from native and non-native forest birds and screened for avian malaria (Plasmodium relictum) using PCR diagnostics. We examined birds for signs of avian pox (Avipoxvirus sp.), knemidokoptic mange (Knemidokoptes jamaicensis) and feather ectoparasites. We also trapped adult mosquitoes (Culex quinquefasciatus and Aedes japonicus japonicus) and surveyed for available larval habitat. Between September, 2012 and October, 2014, we completed 3,219 hours of mist-netting in Kahuku capturing 515 forest birds and 3,103 hours of mist-netting in Ka‘u capturing 270 forest birds. We screened 750 blood samples for avian malaria. Prevalence of avian malaria in all species was higher in Ka‘u than Kahuku when all sites were combined for each tract. Prevalence of avian malaria in resident Hawai‘i ‘amakihi (Chlorodrepanis virens) was greatest at the lowest elevation sites in Kahuku (26%; 1,201 m asl) and Ka‘u (42%; 1,178 m asl) and in general, prevalence decreased with increasing elevation and geographically from east to west. Significantly higher prevalence was seen in Ka‘u at comparable low and mid elevation sites but not at comparable high elevation sites. The overall presumptive pox prevalence was 1.7% (13/785) for both tracts, and it was higher in native birds than non-native birds, but it was not significant. Presumptive knemidokoptic mange was detected at two sites in lower elevation Kahuku, with prevalence ranging from 2‒4%. The overall prevalence of ectoparasites (Analges and Proctophyllodes spp.) was 6.7% (53/785). The site with the highest prevalence was Lower Glover in Kahuku (7.2%; 10/138) and Maka‘alia in Ka‘u. In general, mosquito larval habitat was more prevalent at lower elevation sites than higher elevation sites within the Kahuku—Ka‘u landscape, and more prevalent in Ka‘u than Kahuku. We observed significantly more available larval mosquito habitat in total belt transect plots in Ka‘u than Kahuku for both hapu‘u cavities (Χ2 = 47.06, df = 1, p < 0.01) and other habitat types combined (i.e., ground pools, rock holes, tree holes) (Χ2 = 104.35, df = 1, p < 0.01). Mosquitoes were most abundant at low elevation Kahuku, but were captured at all sites up to 1,532 m asl in Kahuku. The malarial infection rate of live mosquitoes was 21% (39/186) at Kahuku and 25% (2/8) at Ka‘u. There were 19 times more larval habitats available in Ka‘u than Kahuku on survey transects, yet we captured 53 times more C. quinquefasciatus mosquitoes in Kahuku. We captured very few adult A. j. japonicus across the landscape (Ntotal = 6) and no Aedes albopictus were detected in this study. Larval surveys along ranch roads and infrastructure revealed that ground pools along rutted, overgrown ranch roads were the likely source of Kahuku mosquitoes. We did not find mosquito larvae associated with ranching infrastructure. Unlike the low elevation forests on windward Hawai‘i Island, avian malaria prevalence, mosquito abundance, and the density of available larval habitat in Kahuku and Ka‘u were relatively low. Although altitudinal variations in climate appear to be the primary factors limiting the distribution of avian disease, habitat type, avian movements, human activity, and feral pig (Sus scrofa) management all may play important roles in determining the prevalence of avian malaria across the Kahuku—Ka‘u landscape.

Optimal control for Malaria disease through vaccination

NASA Astrophysics Data System (ADS)

Munzir, Said; Nasir, Muhammad; Ramli, Marwan

2018-01-01

Malaria is a disease caused by an amoeba (single-celled animal) type of plasmodium where anopheles mosquito serves as the carrier. This study examines the optimal control problem of malaria disease spread based on Aron and May (1982) SIR type models and seeks the optimal solution by minimizing the prevention of the spreading of malaria by vaccine. The aim is to investigate optimal control strategies on preventing the spread of malaria by vaccination. The problem in this research is solved using analytical approach. The analytical method uses the Pontryagin Minimum Principle with the symbolic help of MATLAB software to obtain optimal control result and to analyse the spread of malaria with vaccination control.

The history of 20th century malaria control in Peru

PubMed Central

2013-01-01

Malaria has been part of Peruvian life since at least the 1500s. While Peru gave the world quinine, one of the first treatments for malaria, its history is pockmarked with endemic malaria and occasional epidemics. In this review, major increases in Peruvian malaria incidence over the past hundred years are described, as well as the human factors that have facilitated these events, and concerted private and governmental efforts to control malaria. Political support for malaria control has varied and unexpected events like vector and parasite resistance have adversely impacted morbidity and mortality. Though the ready availability of novel insecticides like DDT and efficacious medications reduced malaria to very low levels for a decade after the post eradication era, malaria reemerged as an important modern day challenge to Peruvian public health. Its reemergence sparked collaboration between domestic and international partners towards the elimination of malaria in Peru. PMID:24001096

Land use and land cover changes and spatiotemporal dynamics of anopheline larval habitats during a four-year period in a highland community of Africa.

PubMed

Munga, Stephen; Yakob, Laith; Mushinzimana, Emmanuel; Zhou, Guofa; Ouna, Tom; Minakawa, Noboru; Githeko, Andrew; Yan, Guiyun

2009-12-01

Spatial and temporal variations in the distribution of anopheline larval habitats and land use and land cover (LULC) changes can influence malaria transmission intensity. This information is important for understanding the environmental determinants of malaria transmission heterogeneity, and it is critical to the study of the effects of environmental changes on malaria transmission. In this study, we investigated the spatial and temporal variations in the distribution of anopheline larval habitats and LULC changes in western Kenya highlands over a 4-year period. Anopheles gambiae complex larvae were mainly confined to valley bottoms during both the dry and wet seasons. Although An. gambiae larvae were located in man-made habitats where riparian forests and natural swamps had been cleared, Anopheles funestus larvae were mainly found in permanent habitats in pastures. The association between land cover type and occurrence of anopheline larvae was statistically significant. The distribution of anopheline positive habitats varied significantly between months, during the survey. In 2004, the mean density of An. gambiae was significantly higher during the month of May, whereas the density of An. funestus peaked significantly in February. Over the study period, major LULC changes occurred mostly in the valley bottoms. Overall, farmland increased by 3.9%, whereas both pastures and natural swamps decreased by 8.9% and 20.9%, respectively. The area under forest cover was decreased by 5.8%. Land-use changes in the study area are favorable to An. gambiae larval development, thereby risking a more widespread distribution of malaria vector habitats and potentially increasing malaria transmission in western Kenya highlands.

Will a warmer and wetter future cause extinction of native Hawaiian forest birds?

PubMed

Liao, Wei; Elison Timm, Oliver; Zhang, Chunxi; Atkinson, Carter T; LaPointe, Dennis A; Samuel, Michael D

2015-12-01

Isolation of the Hawaiian archipelago produced a highly endemic and unique avifauna. Avian malaria (Plasmodium relictum), an introduced mosquito-borne pathogen, is a primary cause of extinctions and declines of these endemic honeycreepers. Our research assesses how global climate change will affect future malaria risk and native bird populations. We used an epidemiological model to evaluate future bird-mosquito-malaria dynamics in response to alternative climate projections from the Coupled Model Intercomparison Project. Climate changes during the second half of the century accelerate malaria transmission and cause a dramatic decline in bird abundance. Different temperature and precipitation patterns produce divergent trajectories where native birds persist with low malaria infection under a warmer and dryer projection (RCP4.5), but suffer high malaria infection and severe reductions under hot and dry (RCP8.5) or warm and wet (A1B) futures. We conclude that future global climate change will cause significant decreases in the abundance and diversity of remaining Hawaiian bird communities. Because these effects appear unlikely before mid-century, natural resource managers have time to implement conservation strategies to protect this unique avifauna from further decimation. Similar climatic drivers for avian and human malaria suggest that mitigation strategies for Hawai'i have broad application to human health. © 2015 John Wiley & Sons Ltd.

Will a warmer and wetter future cause extinction of native Hawaiian forest birds?

USGS Publications Warehouse

Liao, Wei; Timm, Oliver Elison; Zhang, Chunxi; Atkinson, Carter T.; LaPointe, Dennis; Samuel, Michael D.

2015-01-01

Isolation of the Hawaiian archipelago produced a highly endemic and unique avifauna. Avian malaria (Plasmodium relictum), an introduced mosquito-borne pathogen, is a primary cause of extinctions and declines of these endemic honeycreepers. Our research assesses how global climate change will affect future malaria risk and native bird populations. We used an epidemiological model to evaluate future bird-mosquito-malaria dynamics in response to alternative climate projections from the Coupled Model Intercomparison Project (CMIP). Climate changes during the second half of the century accelerate malaria transmission and cause a dramatic decline in bird abundance. Different temperature and precipitation patterns produce divergent trajectories where native birds persist with low malaria infection under a warmer and dryer projection (RCP4.5), but suffer high malaria infection and severe reductions under hot and dry (RCP8.5) or warm and wet (A1B) futures. We conclude that future global climate change will cause significant decreases in the abundance and diversity of remaining Hawaiian bird communities. Because these effects appear unlikely before mid-century, natural resource managers have time to implement conservation strategies to protect this unique avifauna from further decimation. Similar climatic drivers for avian and human malaria suggest that mitigation strategies for Hawai'i have broad application to human health.

Novel Cross-Border Approaches to Optimise Identification of Asymptomatic and Artemisinin-Resistant Plasmodium Infection in Mobile Populations Crossing Cambodian Borders

PubMed Central

Edwards, Hannah M.; Canavati, Sara E.; Rang, Chandary; Ly, Po; Sovannaroth, Siv; Canier, Lydie; Khim, Nimol; Menard, Didier; Ashton, Ruth A.; Meek, Sylvia R.; Roca-Feltrer, Arantxa

2015-01-01

Background Human population movement across country borders presents a real challenge for malaria control and elimination efforts in Cambodia and its neighbouring countries. To quantify Plasmodium infection among the border-crossing population, including asymptomatic and artemisinin resistant (AR) parasites, three official border crossing points, one from each of Cambodia's borders with Thailand, Laos and Vietnam, were selected for sampling. Methods and Findings A total of 3206 participants (of 4110 approached) were recruited as they crossed the border, tested for malaria and interviewed. By real-time polymerase chain reaction (RT-PCR), 5.4% of all screened individuals were found to harbour Plasmodium parasites. The proportion was highest at the Laos border (11.5%). Overall there were 97 P. vivax (55.7%), 55 P. falciparum (31.6%), two P. malariae (1.1%) and 20 mixed infections (11.5%). Of identified infections, only 20% were febrile at the time of screening. Of the 24 P. falciparum samples where a further PCR was possible to assess AR, 15 (62.5%) had mutations in the K13 propeller domain gene, all from participants at the Laos border point. Malaria rapid diagnostic test (RDT) pLDH/HRP-2 identified a positivity rate of 3.2% overall and sensitivity compared to RT-PCR was very low (43.1%). Main individual risk factors for infection included sex, fever, being a forest-goer, poor knowledge of malaria prevention methods and previous malaria infection. Occupation, day of the week and time of crossing (morning vs. afternoon) also appeared to play an important role in predicting positive cases. Conclusions This study offers a novel approach to identify asymptomatic infections and monitor AR parasite flow among mobile and migrant populations crossing the borders. Similar screening activities are recommended to identify other hot borders and characterise potential hot spots of AR. Targeted “customised” interventions and surveillance activities should be implemented in these sites to accelerate elimination efforts in the region. PMID:26352262

Large-Scale Range Collapse of Hawaiian Forest Birds under Climate Change and the Need 21st Century Conservation Options

PubMed Central

Fortini, Lucas B.; Vorsino, Adam E.; Amidon, Fred A.; Paxton, Eben H.; Jacobi, James D.

2015-01-01

Hawaiian forest birds serve as an ideal group to explore the extent of climate change impacts on at-risk species. Avian malaria constrains many remaining Hawaiian forest bird species to high elevations where temperatures are too cool for malaria’s life cycle and its principal mosquito vector. The impact of climate change on Hawaiian forest birds has been a recent focus of Hawaiian conservation biology, and has centered on the links between climate and avian malaria. To elucidate the differential impacts of projected climate shifts on species with known varying niches, disease resistance and tolerance, we use a comprehensive database of species sightings, regional climate projections and ensemble distribution models to project distribution shifts for all Hawaiian forest bird species. We illustrate that, under a likely scenario of continued disease-driven distribution limitation, all 10 species with highly reliable models (mostly narrow-ranged, single-island endemics) are expected to lose >50% of their range by 2100. Of those, three are expected to lose all range and three others are expected to lose >90% of their range. Projected range loss was smaller for several of the more widespread species; however improved data and models are necessary to refine future projections. Like other at-risk species, Hawaiian forest birds have specific habitat requirements that limit the possibility of range expansion for most species, as projected expansion is frequently in areas where forest habitat is presently not available (such as recent lava flows). Given the large projected range losses for all species, protecting high elevation forest alone is not an adequate long-term strategy for many species under climate change. We describe the types of additional conservation actions practitioners will likely need to consider, while providing results to help with such considerations. PMID:26509270

Ranking malaria risk factors to guide malaria control efforts in African highlands.

PubMed

Protopopoff, Natacha; Van Bortel, Wim; Speybroeck, Niko; Van Geertruyden, Jean-Pierre; Baza, Dismas; D'Alessandro, Umberto; Coosemans, Marc

2009-11-25

Malaria is re-emerging in most of the African highlands exposing the non immune population to deadly epidemics. A better understanding of the factors impacting transmission in the highlands is crucial to improve well targeted malaria control strategies. A conceptual model of potential malaria risk factors in the highlands was built based on the available literature. Furthermore, the relative importance of these factors on malaria can be estimated through "classification and regression trees", an unexploited statistical method in the malaria field. This CART method was used to analyse the malaria risk factors in the Burundi highlands. The results showed that Anopheles density was the best predictor for high malaria prevalence. Then lower rainfall, no vector control, higher minimum temperature and houses near breeding sites were associated by order of importance to higher Anopheles density. In Burundi highlands monitoring Anopheles densities when rainfall is low may be able to predict epidemics. The conceptual model combined with the CART analysis is a decision support tool that could provide an important contribution toward the prevention and control of malaria by identifying major risk factors.

Challenges and prospects for dengue and malaria control in Thailand, Southeast Asia.

PubMed

Corbel, Vincent; Nosten, Francois; Thanispong, Kanutcharee; Luxemburger, Christine; Kongmee, Monthathip; Chareonviriyaphap, Theeraphap

2013-12-01

Despite significant advances in the search for potential dengue vaccines and new therapeutic schemes for malaria, the control of these diseases remains difficult. In Thailand, malaria incidence is falling whereas that of dengue is rising, with an increase in the proportion of reported severe cases. In the absence of antiviral therapeutic options for acute dengue, appropriate case management reduces mortality. However, the interruption of transmission still relies on vector control measures that are currently insufficient to curtail the cycle of epidemics. Drug resistance in malaria parasites is increasing, compromising malaria control and elimination. Deficiencies in our knowledge of vector biology and vectorial capacity also hinder public health efforts for vector control. Challenges to dengue and malaria control are discussed, and research priorities identified. Copyright © 2013. Published by Elsevier Ltd.

Assessment of the impact of the malaria elimination programme on the burden of disease morbidity in endemic areas of Iran.

PubMed

Sheikhzadeh, Khodadad; Haghdoost, Ali Akbar; Bahrampour, Abbas; Zolala, Farzaneh; Raeisi, Ahmad

2016-04-14

Controlling and preventive measures considerably reduced malaria incidence in Iran over the past few years, which confined the endemic areas to some regions in the southeastern Iran. The National Malaria Elimination Programme commenced in 2010. With regard to the presumption that the elimination programme interventions have accelerated the declining trend of malaria incidence across the endemic areas of Iran, the present study attempted to assess the effectiveness of the elimination programme by reviewing malaria incidence status, over a 14-year period, and comparing the trend of malaria incidence across malaria-endemic areas between the control and pre-elimination phase, and the elimination phase. A retrospective analysis of malaria surveillance data was conducted in a 14-year period (2001-2014), using multilevel Poisson regression. The epidemiological malaria maps and indicators also were developed and compared between the control and pre-elimination phase, and the elimination phase. The mean of malaria incidence was 2.2 (1.7-2.7) for the entire study period. This rate was 3.4 (2.6-4.1) in the control and pre-elimination phase, and 0.41 (0.25-0.57) for the elimination phase. During the malaria elimination phase, the decline of annual malaria incidence had significantly accelerated and autochthonous cases had the greatest difference in malaria incidence decline (compared to the control and pre-elimination phase), whereas, falciparum cases had the lowest difference in malaria incidence decline, followed by non-Iranian and imported cases. Furthermore, there was a decline in Iranians to non-Iranians ratio and an increase in the ratios of over 15 to under 15, as well as male to female, in the elimination phase in comparison to the control and pre-elimination phase. It seems that the decline of malaria transmission, which has been initiated over the past few years, has accelerated as a result of the elimination programme, and Iran is approaching the goals set regarding the elimination of this disease.

Quantifying the impact of decay in bed-net efficacy on malaria transmission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ngonghala, Calistus N.; Del Valle, Sara Y.; Zhao, Ruijun

Insecticide-treated nets (ITNs) are at the forefront of malaria control programs and even though the percentage of households in sub-Saharan Africa that owned nets increased from 3% in 2000 to 53% in 2012, many children continue to die from malaria. The potential impact of ITNs on reducing malaria transmission is limited due to inconsistent or improper use, as well as physical decay in effectiveness. Most mathematical models for malaria transmission have assumed a fixed effectiveness rate for bed-nets, which can overestimate the impact of nets on malaria control. We develop a model for malaria spread that captures the decrease inmore » ITN effectiveness due to physical and chemical decay, as well as human behavior as a function of time. We perform uncertainty and sensitivity analyses to identify and rank parameters that play a critical role in malaria transmission. These analyses show that the basic reproduction number R 0, and the infectious human population are most sensitive to bed-net coverage and the biting rate of mosquitoes. Our results show the existence of a backward bifurcation for the case in which ITN efficacy is constant over time, which occurs for some range of parameters and is characterized by high malaria mortality in humans. This result implies that bringing R 0 to less than one is not enough for malaria elimination but rather additional efforts will be necessary to control the disease. For the case in which ITN efficacy decays over time, we determine coverage levels required to control malaria for different ITN efficacies and demonstrate that ITNs with longer useful lifespans perform better in malaria control. We conclude that malaria control programs should focus on increasing bed-net coverage, which can be achieved by enhancing malaria education and increasing bed-net distribution in malaria endemic regions.« less

Quantifying the impact of decay in bed-net efficacy on malaria transmission

DOE PAGES

Ngonghala, Calistus N.; Del Valle, Sara Y.; Zhao, Ruijun; ...

2014-08-23

Insecticide-treated nets (ITNs) are at the forefront of malaria control programs and even though the percentage of households in sub-Saharan Africa that owned nets increased from 3% in 2000 to 53% in 2012, many children continue to die from malaria. The potential impact of ITNs on reducing malaria transmission is limited due to inconsistent or improper use, as well as physical decay in effectiveness. Most mathematical models for malaria transmission have assumed a fixed effectiveness rate for bed-nets, which can overestimate the impact of nets on malaria control. We develop a model for malaria spread that captures the decrease inmore » ITN effectiveness due to physical and chemical decay, as well as human behavior as a function of time. We perform uncertainty and sensitivity analyses to identify and rank parameters that play a critical role in malaria transmission. These analyses show that the basic reproduction number R 0, and the infectious human population are most sensitive to bed-net coverage and the biting rate of mosquitoes. Our results show the existence of a backward bifurcation for the case in which ITN efficacy is constant over time, which occurs for some range of parameters and is characterized by high malaria mortality in humans. This result implies that bringing R 0 to less than one is not enough for malaria elimination but rather additional efforts will be necessary to control the disease. For the case in which ITN efficacy decays over time, we determine coverage levels required to control malaria for different ITN efficacies and demonstrate that ITNs with longer useful lifespans perform better in malaria control. We conclude that malaria control programs should focus on increasing bed-net coverage, which can be achieved by enhancing malaria education and increasing bed-net distribution in malaria endemic regions.« less

Malaria successes and challenges in Asia.

PubMed

Bhatia, Rajesh; Rastogi, Rakesh Mani; Ortega, Leonard

2013-12-01

Asia ranks second to Africa in terms of malaria burden. In 19 countries of Asia, malaria is endemic and 2.31 billion people or 62% of the total population in these countries are at risk of malaria. In 2010, WHO estimated around 34.8 million cases and 45,600 deaths due to malaria in Asia. In 2011, 2.7 million cases and > 2000 deaths were reported. India, Indonesia, Myanmar and Pakistan are responsible for >85% of the reported cases (confirmed) and deaths in Asia. In last 10 yr, due to availability of donor's fund specially from Global fund, significant progress has been made by the countries in Asia in scaling-up malaria control interventions which were instrumental in reducing malaria morbidity and mortality significantly. There is a large heterogeneity in malaria epidemiology in Asia. As a result, the success in malaria control/elimination is also diverse. As compared to the data of the year 2000, out of 19 malaria endemic countries, 12 countries were able to reduce malaria incidence (microscopically confirmed cases only) by 75%. Two countries, namely Bangladesh and Malaysia are projected to reach 75% reduction by 2015 while India is projected to reach 50-75% only by 2015. The trend could not be assessed in four countries, namely Indonesia, Myanmar, Pakistan and Timor-Leste due to insufficient consistent data. Numerous key challenges need to be addressed to sustain the gains and eliminate malaria in most parts of Asia. Some of these are to control the spread of resistance in Plasmodium falciparum to artemisinin, control of outdoor transmission, control of vivax malaria and ensuring universal coverage of key interventions. Asia has the potential to influence the malaria epidemiology all over the world as well as to support the global efforts in controlling and eliminating malaria through production of quality-assured ACTs, RDTs and long-lasting insecticidal nets.

Genome-wide QTL mapping of saltwater tolerance in sibling species of Anopheles (malaria vector) mosquitoes

PubMed Central

Smith, H A; White, B J; Kundert, P; Cheng, C; Romero-Severson, J; Andolfatto, P; Besansky, N J

2015-01-01

Although freshwater (FW) is the ancestral habitat for larval mosquitoes, multiple species independently evolved the ability to survive in saltwater (SW). Here, we use quantitative trait locus (QTL) mapping to investigate the genetic architecture of osmoregulation in Anopheles mosquitoes, vectors of human malaria. We analyzed 1134 backcross progeny from a cross between the obligate FW species An. coluzzii, and its closely related euryhaline sibling species An. merus. Tests of 2387 markers with Bayesian interval mapping and machine learning (random forests) yielded six genomic regions associated with SW tolerance. Overlap in QTL regions from both approaches enhances confidence in QTL identification. Evidence exists for synergistic as well as disruptive epistasis among loci. Intriguingly, one QTL region containing ion transporters spans the 2Rop chromosomal inversion that distinguishes these species. Rather than a simple trait controlled by one or a few loci, our data are most consistent with a complex, polygenic mode of inheritance. PMID:25920668

Application of loop analysis for evaluation of malaria control interventions.

PubMed

Yasuoka, Junko; Jimba, Masamine; Levins, Richard

2014-04-09

Despite continuous efforts and recent rapid expansion in the financing and implementation of malaria control interventions, malaria still remains one of the most devastating global health issues. Even in countries that have been successful in reducing the incidence of malaria, malaria control is becoming more challenging because of the changing epidemiology of malaria and waning community participation in control interventions. In order to improve the effectiveness of interventions and to promote community understanding of the necessity of continued control efforts, there is an urgent need to develop new methodologies that examine the mechanisms by which community-based malaria interventions could reduce local malaria incidence. This study demonstrated how the impact of community-based malaria control interventions on malaria incidence can be examined in complex systems by qualitative analysis combined with an extensive review of literature. First, sign digraphs were developed through loop analysis to analyse seven interventions: source reduction, insecticide/larvicide use, biological control, treatment with anti-malarials, insecticide-treated mosquito net/long-lasting insecticidal net, non-chemical personal protection measures, and educational intervention. Then, for each intervention, the sign digraphs and literature review were combined to analyse a variety of pathways through which the intervention can influence local malaria incidence as well as interactions between variables involved in the system. Through loop analysis it is possible to see whether increases in one variable qualitatively increases or decreases other variables or leaves them unchanged and the net effect of multiple, interacting variables. Qualitative analysis, specifically loop analysis, can be a useful tool to examine the impact of community-based malaria control interventions. Without relying on numerical data, the analysis was able to describe pathways through which each intervention could influence malaria incidence on the basis of the qualitative patterns of the interactions between variables in complex systems. This methodology is generalizable to various disease control interventions at different levels, and can be utilized by a variety of stakeholders such as researchers, community leaders and policy makers to better plan and evaluate their community-based disease control interventions.

Application of loop analysis for evaluation of malaria control interventions

PubMed Central

2014-01-01

Background Despite continuous efforts and recent rapid expansion in the financing and implementation of malaria control interventions, malaria still remains one of the most devastating global health issues. Even in countries that have been successful in reducing the incidence of malaria, malaria control is becoming more challenging because of the changing epidemiology of malaria and waning community participation in control interventions. In order to improve the effectiveness of interventions and to promote community understanding of the necessity of continued control efforts, there is an urgent need to develop new methodologies that examine the mechanisms by which community-based malaria interventions could reduce local malaria incidence. Methods This study demonstrated how the impact of community-based malaria control interventions on malaria incidence can be examined in complex systems by qualitative analysis combined with an extensive review of literature. First, sign digraphs were developed through loop analysis to analyse seven interventions: source reduction, insecticide/larvicide use, biological control, treatment with anti-malarials, insecticide-treated mosquito net/long-lasting insecticidal net, non-chemical personal protection measures, and educational intervention. Then, for each intervention, the sign digraphs and literature review were combined to analyse a variety of pathways through which the intervention can influence local malaria incidence as well as interactions between variables involved in the system. Through loop analysis it is possible to see whether increases in one variable qualitatively increases or decreases other variables or leaves them unchanged and the net effect of multiple, interacting variables. Results Qualitative analysis, specifically loop analysis, can be a useful tool to examine the impact of community-based malaria control interventions. Without relying on numerical data, the analysis was able to describe pathways through which each intervention could influence malaria incidence on the basis of the qualitative patterns of the interactions between variables in complex systems. This methodology is generalizable to various disease control interventions at different levels, and can be utilized by a variety of stakeholders such as researchers, community leaders and policy makers to better plan and evaluate their community-based disease control interventions. PMID:24713031

Modeling malaria control intervention effect in KwaZulu-Natal, South Africa using intervention time series analysis.

PubMed

Ebhuoma, Osadolor; Gebreslasie, Michael; Magubane, Lethumusa

The change of the malaria control intervention policy in South Africa (SA), re-introduction of dichlorodiphenyltrichloroethane (DDT), may be responsible for the low and sustained malaria transmission in KwaZulu-Natal (KZN). We evaluated the effect of the re-introduction of DDT on malaria in KZN and suggested practical ways the province can strengthen her already existing malaria control and elimination efforts, to achieve zero malaria transmission. We obtained confirmed monthly malaria cases in KZN from the malaria control program of KZN from 1998 to 2014. The seasonal autoregressive integrated moving average (SARIMA) intervention time series analysis (ITSA) was employed to model the effect of the re-introduction of DDT on confirmed monthly malaria cases. The result is an abrupt and permanent decline of monthly malaria cases (w 0 =-1174.781, p-value=0.003) following the implementation of the intervention policy. The sustained low malaria cases observed over a long period suggests that the continued usage of DDT did not result in insecticide resistance as earlier anticipated. It may be due to exophagic malaria vectors, which renders the indoor residual spraying not totally effective. Therefore, the feasibility of reducing malaria transmission to zero in KZN requires other reliable and complementary intervention resources to optimize the existing ones. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

DDT, global strategies, and a malaria control crisis in South America.

PubMed

Roberts, D R; Laughlin, L L; Hsheih, P; Legters, L J

1997-01-01

Malaria is reemerging in endemic-disease countries of South America. We examined the rate of real growth in annual parasite indexes (API) by adjusting APIs for all years to the annual blood examination rate of 1965 for each country. The standardized APIs calculated for Brazil, Peru, Guyana, and for 18 other malaria-endemic countries of the Americas presented a consistent pattern of low rates up through the late 1970s, followed by geometric growth in malaria incidence in subsequent years. True growth in malaria incidence corresponds temporally with changes in global strategies for malaria control. Underlying the concordance of these events is a causal link between decreased spraying of homes with DDT and increased malaria; two regression models defining this link showed statistically significant negative relationships between APIs and house-spray rates. Separate analyses of data from 1993 to 1995 showed that countries that have recently discontinued their spray programs are reporting large increases in malaria incidence. Ecuador, which has increased use of DDT since 1993, is the only country reporting a large reduction (61%) in malaria rates since 1993. DDT use for malaria control and application of the Global Malaria Control Strategy to the Americas should be subjects of urgent national and international debate. We discuss the recent actions to ban DDT, the health costs of such a ban, perspectives on DDT use in agriculture versus malaria control, and costs versus benefits of DDT and alternative insecticides.

DDT, global strategies, and a malaria control crisis in South America.

PubMed Central

Roberts, D. R.; Laughlin, L. L.; Hsheih, P.; Legters, L. J.

1997-01-01

Malaria is reemerging in endemic-disease countries of South America. We examined the rate of real growth in annual parasite indexes (API) by adjusting APIs for all years to the annual blood examination rate of 1965 for each country. The standardized APIs calculated for Brazil, Peru, Guyana, and for 18 other malaria-endemic countries of the Americas presented a consistent pattern of low rates up through the late 1970s, followed by geometric growth in malaria incidence in subsequent years. True growth in malaria incidence corresponds temporally with changes in global strategies for malaria control. Underlying the concordance of these events is a causal link between decreased spraying of homes with DDT and increased malaria; two regression models defining this link showed statistically significant negative relationships between APIs and house-spray rates. Separate analyses of data from 1993 to 1995 showed that countries that have recently discontinued their spray programs are reporting large increases in malaria incidence. Ecuador, which has increased use of DDT since 1993, is the only country reporting a large reduction (61%) in malaria rates since 1993. DDT use for malaria control and application of the Global Malaria Control Strategy to the Americas should be subjects of urgent national and international debate. We discuss the recent actions to ban DDT, the health costs of such a ban, perspectives on DDT use in agriculture versus malaria control, and costs versus benefits of DDT and alternative insecticides. PMID:9284373

Optimal strategy for controlling the spread of Plasmodium Knowlesi malaria: Treatment and culling

NASA Astrophysics Data System (ADS)

Abdullahi, Mohammed Baba; Hasan, Yahya Abu; Abdullah, Farah Aini

2015-05-01

Plasmodium Knowlesi malaria is a parasitic mosquito-borne disease caused by a eukaryotic protist of genus Plasmodium Knowlesi transmitted by mosquito, Anopheles leucosphyrus to human and macaques. We developed and analyzed a deterministic Mathematical model for the transmission of Plasmodium Knowlesi malaria in human and macaques. The optimal control theory is applied to investigate optimal strategies for controlling the spread of Plasmodium Knowlesi malaria using treatment and culling as control strategies. The conditions for optimal control of the Plasmodium Knowlesi malaria are derived using Pontryagin's Maximum Principle. Finally, numerical simulations suggested that the combination of the control strategies is the best way to control the disease in any community.

Challenges and prospects for malaria elimination in the Greater Mekong Subregion

PubMed Central

Cui, Liwang; Yan, Guiyun; Sattabongkot, Jetsumon; Chen, Bin; Cao, Yaming; Fan, Qi; Parker, Daniel; Sirichaisinthop, Jeeraphat; Su, Xin-zhuan; Yang, Henglin; Yang, Zhaoqing; Wang, Baomin; Zhou, Guofa

2011-01-01

Despite significant improvement in the malaria situation of the Greater Mekong Subregion (GMS), malaria control for the region continues to face a multitude of challenges. The extremely patchy malaria distribution, especially along international borders, makes disease surveillance and targeted control difficult. The vector systems are also diverse with dramatic differences in habitat ecology, biting behavior, and vectorial capacity, and there is a lack of effective transmission surveillance and control tools. Finally, in an era of heavy deployment of artemisinin-based combination therapies, the region acts as an epicenter of drug resistance, with the emergence of artemisinin resistant P. falciparum posing a threat to both regional and global malaria elimination campaigns. This problem is further exacerbated by the circulation of counterfeit and substandard artemisinin drugs. Accordingly, this Southeast Asian Malaria Research Center, consisting of a consortium of US and regional research institutions, has proposed four interlinked projects to address these most urgent problems in malaria control. The aims of these projects will help to substantially improve our understanding of malaria epidemiology, vector systems and their roles in malaria transmission, as well as the mechanisms of drug resistance in parasites. Through the training of next-generation scientists in malaria research, this program will help build up and strengthen regional research infrastructure and capacities, which are essential for sustained malaria control in this region. PMID:21515238

Malaria control in Nicaragua: social and political influences on disease transmission and control activities.

PubMed

Garfield, R

1999-07-31

Throughout Central America, a traditional malaria control strategy (depending on heavy use of organic pesticides) became less effective during the 1970s. In Nicaragua, an alternative strategy, based on frequent local epidemiological assessments and community participation, was developed in the 1980s. Despite war-related social instability, and continuing vector resistance, this approach was highly successful. By the end of the contra war, there finally existed organisational and ecological conditions that favoured improved malaria control. Yet the expected improvements did not occur. In the 1990s, Nicaragua experienced its worst recorded malaria epidemics. This situation was partly caused by the country's macroeconomic structural adjustment programme. Volunteers now take fewer slides and provide less treatment, malaria control workers are less motivated by the spirit of public service, and some malaria control stations charge for diagnosis or treatment. To "roll back malaria", in Nicaragua at least, will require the roll-back of some erroneous aspects of structural adjustment.

Malaria Control and Elimination,1 Venezuela, 1800s–1970s

PubMed Central

Villegas, Leopoldo; Udhayakumar, Venkatachalam

2014-01-01

Venezuela had the highest number of human malaria cases in Latin American before 1936. During 1891–1920, malaria was endemic to >600,000 km2 of this country; malaria death rates led to major population decreases during 1891–1920. No pathogen, including the influenza virus that caused the 1918 pandemic, caused more deaths than malaria during 1905–1945. Early reports of malaria eradication in Venezuela helped spark the world’s interest in global eradication. We describe early approaches to malaria epidemiology in Venezuela and how this country developed an efficient control program and an approach to eradication. Arnoldo Gabaldón was a key policy maker during this development process. He directed malaria control in Venezuela from the late 1930s to the end of the 1970s and contributed to malaria program planning of the World Health Organization. We discuss how his efforts helped reduce the incidence of malaria in Venezuela and how his approach diverged from World Health Organization guidelines.

Malaria control and elimination, Venezuela, 1800s –1970s.

PubMed

Griffing, Sean M; Villegas, Leopoldo; Udhayakumar, Venkatachalam

2014-10-01

Venezuela had the highest number of human malaria cases in Latin American before 1936. During 1891–1920,malaria was endemic to >600,000 km2 of this country; malaria death rates led to major population decreases during 1891–1920. No pathogen, including the influenza virus that caused the 1918 pandemic, caused more deaths than malaria during 1905–1945. Early reports of malaria eradication in Venezuela helped spark the world's interest in global eradication. We describe early approaches to malaria epidemiology in Venezuela and how this country developed an efficient control program and an approach to eradication.Arnoldo Gabaldón was a key policy maker during this development process. He directed malaria control in Venezuela from the late 1930s to the end of the 1970s and contributed to malaria program planning of the World Health Organization.We discuss how his efforts helped reduce the incidence of malaria in Venezuela and how his approach diverged from World Health Organization guidelines.

Antiplasmodial potential of traditional phytotherapy of some remedies used in treatment of malaria in Meru-Tharaka Nithi County of Kenya.

PubMed

Muthaura, C N; Keriko, J M; Mutai, C; Yenesew, Abiy; Gathirwa, J W; Irungu, B N; Nyangacha, R; Mungai, G M; Derese, Solomon

2015-12-04

Medicinal plants play a major role in many communities across the world, in the treatment and prevention of disease and the promotion of general health. The aim of the study was to escalate documentation from an earlier study of medicinal plants, traditionally used to combat malaria by the Ameru community of Imenti Forest area and Gatunga in Eastern Region of Kenya, and validate their ethnopharmacological claims by evaluating their antiplasmodial efficacies. The study was carried out in Meru County at Imenti Forest Game Reserve and in Tharaka Nithi County at Gatunga. Traditional health practitioners (THP) were interviewed with a standard questionnaire to obtain information on medicinal plants traditionally used for management of malaria. Group interviews were also held among THPs and members of the community. The antiplasmodial activities of the crude extracts against chloroquine sensitive (D6) and resistant (W2) Plasmodium falciparum were determined using the semi-automated micro-dilution technique that measures the ability of the extracts to inhibit the incorporation of (G-3H) hypoxanthine into the malaria parasite. Ninety nine (99) species in eighty one (81) genera and forty five (45) families were documented and evaluated for in vitro antiplasmodial activity. Compositae, Fabaceae, Meliceae, Rubiaceae, Rutaceae and Verbenaceae had the highest number of species mentioned in treatment of malaria in Meru/Tharaka Nithi study area. Twenty four (24.2%) species showed antiplasmodial efficacy of IC50 ≤ 5 µg/ml and were considered to have potential for isolation of antimalarial compounds. Eight plant (8) species with moderate antiplasmodial activity namely; Cordia africana, Commiphora africana, Elaeodendron buchananii, Gomphocarpus semilunatus, Tarena graveolens, Plectranthus igniarius, Acacia senegal and Ziziphus abyssinica were documented from this region for the first time for the treatment of malaria. The antiplasmodial activity of MeOH root bark extract of Maytenus obtusifolia was very promising (IC50 < 1.9 µg/ml) and this is the first report on traditional use of M. obtusifolia for treatment of malaria and antimalarial activity. The results seem to indicate that ethnopharmacological inquiry used in search for new herbal remedies as predictive and could be used as the basis for search of new active principles. Eight plant (8) species are documented from this region for the first time for the treatment of malaria. This is the first report on traditional use of M. obtusifolia for treatment of malaria and evaluation of its antiplasmodial activity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Malaria eradication: the economic, financial and institutional challenge.

PubMed

Mills, Anne; Lubell, Yoel; Hanson, Kara

2008-12-11

Malaria eradication raises many economic, financial and institutional challenges. This paper reviews these challenges, drawing on evidence from previous efforts to eradicate malaria, with a special focus on resource-poor settings; summarizes more recent evidence on the challenges, drawing on the literature on the difficulties of scaling-up malaria control and strengthening health systems more broadly; and explores the implications of these bodies of evidence for the current call for elimination and intensified control. Economic analyses dating from the eradication era, and more recent analyses, suggest that, in general, the benefits of malaria control outweigh the costs, though few studies have looked at the relative returns to eradication versus long-term control. Estimates of financial costs are scanty and difficult to compare. In the 1960s, the consolidation phase appeared to cost less than $1 per capita and, in 1988, was estimated to be $2.31 per capita (both in 2006 prices). More recent estimates for high coverage of control measures suggest a per capita cost of several dollars. Institutional challenges faced by malaria eradication included limits to the rule of law (a major problem where malaria was concentrated in border areas with movement of people associated with illegal activities), the existence and performance of local implementing structures, and political sustainability at national and global levels. Recent analyses of the constraints to scaling-up malaria control, together with the historical evidence, are used to discuss the economic, financial and institutional challenges that face the renewed call for eradication and intensified control. The paper concludes by identifying a research agenda covering: issues of the allocative efficiency of malaria eradication, especially using macro-economic modelling to estimate the benefits and costs of malaria eradication and intensified control, and studies of the links between malaria control and economic development, the costs and consequences of the various tools and mixes of tools employed in control and eradication, issues concerning the extension of coverage of interventions and service delivery approaches, especially those that can reach the poorest, research on the processes of formulating and implementing malaria control and eradication policies, at both international and national levels, research on financing issues, at global and national levels.

Malaria eradication: the economic, financial and institutional challenge

PubMed Central

Mills, Anne; Lubell, Yoel; Hanson, Kara

2008-01-01

Malaria eradication raises many economic, financial and institutional challenges. This paper reviews these challenges, drawing on evidence from previous efforts to eradicate malaria, with a special focus on resource-poor settings; summarizes more recent evidence on the challenges, drawing on the literature on the difficulties of scaling-up malaria control and strengthening health systems more broadly; and explores the implications of these bodies of evidence for the current call for elimination and intensified control. Economic analyses dating from the eradication era, and more recent analyses, suggest that, in general, the benefits of malaria control outweigh the costs, though few studies have looked at the relative returns to eradication versus long-term control. Estimates of financial costs are scanty and difficult to compare. In the 1960s, the consolidation phase appeared to cost less than $1 per capita and, in 1988, was estimated to be $2.31 per capita (both in 2006 prices). More recent estimates for high coverage of control measures suggest a per capita cost of several dollars. Institutional challenges faced by malaria eradication included limits to the rule of law (a major problem where malaria was concentrated in border areas with movement of people associated with illegal activities), the existence and performance of local implementing structures, and political sustainability at national and global levels. Recent analyses of the constraints to scaling-up malaria control, together with the historical evidence, are used to discuss the economic, financial and institutional challenges that face the renewed call for eradication and intensified control. The paper concludes by identifying a research agenda covering: ∘ issues of the allocative efficiency of malaria eradication, especially using macro-economic modelling to estimate the benefits and costs of malaria eradication and intensified control, and studies of the links between malaria control and economic development ∘ the costs and consequences of the various tools and mixes of tools employed in control and eradication ∘ issues concerning the extension of coverage of interventions and service delivery approaches, especially those that can reach the poorest ∘ research on the processes of formulating and implementing malaria control and eradication policies, at both international and national levels ∘ research on financing issues, at global and national levels. PMID:19091035

Revisiting the Basic Reproductive Number for Malaria and Its Implications for Malaria Control

PubMed Central

Smith, David L; McKenzie, F. Ellis; Snow, Robert W; Hay, Simon I

2007-01-01

The prospects for the success of malaria control depend, in part, on the basic reproductive number for malaria, R 0. Here, we estimate R 0 in a novel way for 121 African populations, and thereby increase the number of R 0 estimates for malaria by an order of magnitude. The estimates range from around one to more than 3,000. We also consider malaria transmission and control in finite human populations, of size H. We show that classic formulas approximate the expected number of mosquitoes that could trace infection back to one mosquito after one parasite generation, Z 0(H), but they overestimate the expected number of infected humans per infected human, R 0(H). Heterogeneous biting increases R 0 and, as we show, Z 0(H), but we also show that it sometimes reduces R 0(H); those who are bitten most both infect many vectors and absorb infectious bites. The large range of R 0 estimates strongly supports the long-held notion that malaria control presents variable challenges across its transmission spectrum. In populations where R 0 is highest, malaria control will require multiple, integrated methods that target those who are bitten most. Therefore, strategic planning for malaria control should consider R 0, the spatial scale of transmission, human population density, and heterogeneous biting. PMID:17311470

Framework for Evaluating the Health Impact of the Scale-Up of Malaria Control Interventions on All-Cause Child Mortality in Sub-Saharan Africa.

PubMed

Yé, Yazoume; Eisele, Thomas P; Eckert, Erin; Korenromp, Eline; Shah, Jui A; Hershey, Christine L; Ivanovich, Elizabeth; Newby, Holly; Carvajal-Velez, Liliana; Lynch, Michael; Komatsu, Ryuichi; Cibulskis, Richard E; Moore, Zhuzhi; Bhattarai, Achuyt

2017-09-01

Concerted efforts from national and international partners have scaled up malaria control interventions, including insecticide-treated nets, indoor residual spraying, diagnostics, prompt and effective treatment of malaria cases, and intermittent preventive treatment during pregnancy in sub-Saharan Africa (SSA). This scale-up warrants an assessment of its health impact to guide future efforts and investments; however, measuring malaria-specific mortality and the overall impact of malaria control interventions remains challenging. In 2007, Roll Back Malaria's Monitoring and Evaluation Reference Group proposed a theoretical framework for evaluating the impact of full-coverage malaria control interventions on morbidity and mortality in high-burden SSA countries. Recently, several evaluations have contributed new ideas and lessons to strengthen this plausibility design. This paper harnesses that new evaluation experience to expand the framework, with additional features, such as stratification, to examine subgroups most likely to experience improvement if control programs are working; the use of a national platform framework; and analysis of complete birth histories from national household surveys. The refined framework has shown that, despite persisting data challenges, combining multiple sources of data, considering potential contributions from both fundamental and proximate contextual factors, and conducting subnational analyses allows identification of the plausible contributions of malaria control interventions on malaria morbidity and mortality.

Battling malaria iceberg incorporating strategic reforms in achieving Millennium Development Goals & malaria elimination in India

PubMed Central

Sharma, V. P.

2012-01-01

Malaria control in India has occupied high priority in health sector consuming major resources of the Central and State governments. Several new initiatives were launched from time to time supported by foreign aids but malaria situation has remained static and worsened in years of good rainfall. At times malaria relented temporarily but returned with vengeance at the local, regional and national level, becoming more resilient by acquiring resistance in the vectors and the parasites. National developments to improve the economy, without health impact assessment, have had adverse consequences by providing enormous breeding grounds for the vectors that have become refractory to interventions. As a result, malaria prospers and its control is in dilemma, as finding additional resources is becoming difficult with the ongoing financial crisis. Endemic countries must contribute to make up the needed resources, if malaria is to be contained. Malaria control requires long term planning, one that will reduce receptivity and vulnerability, and uninterrupted financial support for sustained interventions. While this seems to be a far cry, the environment is becoming more receptive for vectors, and epidemics visit the country diverting major resources in their containment, e.g. malaria, dengue and dengue haemorrhagic fevers, and Chikungunya virus infection. In the last six decades malaria has taken deep roots and diversified into various ecotypes, the control of these ecotypes requires local knowledge about the vectors and the parasites. In this review we outline the historical account of malaria and methods of control that have lifted the national economy in many countries. While battles against malaria should continue at the local level, there is a need for large scale environmental improvement. Global Fund for AIDS, Tuberculosis and Malaria has provided huge funds for malaria control worldwide touching US$ 2 billion in 2011. Unfortunately it is likely to decline to US$ 1.5 billion in the coming years against the annual requirement of US$ 5 billion. While appreciating the foreign assistance, we wish to highlight the fact that unless we have internal strength of resources and manpower, sustained battles against malaria may face serious problems in achieving the final goal of malaria elimination. PMID:23391787

Battling malaria iceberg incorporating strategic reforms in achieving Millennium Development Goals & malaria elimination in India.

PubMed

Sharma, V P

2012-12-01

Malaria control in India has occupied high priority in health sector consuming major resources of the Central and State governments. Several new initiatives were launched from time to time supported by foreign aids but malaria situation has remained static and worsened in years of good rainfall. At times malaria relented temporarily but returned with vengeance at the local, regional and national level, becoming more resilient by acquiring resistance in the vectors and the parasites. National developments to improve the economy, without health impact assessment, have had adverse consequences by providing enormous breeding grounds for the vectors that have become refractory to interventions. As a result, malaria prospers and its control is in dilemma, as finding additional resources is becoming difficult with the ongoing financial crisis. Endemic countries must contribute to make up the needed resources, if malaria is to be contained. Malaria control requires long term planning, one that will reduce receptivity and vulnerability, and uninterrupted financial support for sustained interventions. While this seems to be a far cry, the environment is becoming more receptive for vectors, and epidemics visit the country diverting major resources in their containment, e.g. malaria, dengue and dengue haemorrhagic fevers, and Chikungunya virus infection. In the last six decades malaria has taken deep roots and diversified into various ecotypes, the control of these ecotypes requires local knowledge about the vectors and the parasites. In this review we outline the historical account of malaria and methods of control that have lifted the national economy in many countries. While battles against malaria should continue at the local level, there is a need for large scale environmental improvement. Global Fund for AIDS, Tuberculosis and Malaria has provided huge funds for malaria control worldwide touching US$ 2 billion in 2011. Unfortunately it is likely to decline to US$ 1.5 billion in the coming years against the annual requirement of US$ 5 billion. While appreciating the foreign assistance, we wish to highlight the fact that unless we have internal strength of resources and manpower, sustained battles against malaria may face serious problems in achieving the final goal of malaria elimination.

"We don't want our clothes to smell smoke": changing malaria control practices and opportunities for integrated community-based management in Baringo, Kenya.

PubMed

Amadi, Jacinter A; Olago, Daniel O; Ong'amo, George O; Oriaso, Silas O; Nyamongo, Isaac K; Estambale, Benson B A

2018-05-09

The decline in global malaria cases is attributed to intensified utilization of primary vector control interventions and artemisinin-based combination therapies (ACTs). These strategies are inadequate in many rural areas, thus adopting locally appropriate integrated malaria control strategies is imperative in these heterogeneous settings. This study aimed at investigating trends and local knowledge on malaria and to develop a framework for malaria control for communities in Baringo, Kenya. Clinical malaria cases obtained from four health facilities in the riverine and lowland zones were used to analyse malaria trends for the 2005-2014 period. A mixed method approach integrating eight focus group discussions, 12 key informant interviews, 300 survey questionnaires and two stakeholders' consultative forums were used to assess local knowledge on malaria risk and develop a framework for malaria reduction. Malaria cases increased significantly during the 2005-2014 period (tau = 0.352; p < 0.001) in the riverine zone. March, April, May, June and October showed significant increases compared to other months. Misconceptions about the cause and mode of malaria transmission existed. Gender-segregated outdoor occupation such as social drinking, farm activities, herding, and circumcision events increased the risk of mosquito bites. A positive relationship occurred between education level and opinion on exposure to malaria risk after dusk (χ 2  = 2.70, p < 0.05). There was over-reliance on bed nets, yet only 68% (204/300) of respondents owned at least one net. Complementary malaria control measures were under-utilized, with 90% of respondents denying having used either sprays, repellents or burnt cow dung or plant leaves over the last one year before the study was conducted. Baraza, radios, and mobile phone messages were identified as effective media for malaria information exchange. Supplementary strategies identified included unblocking canals, clearing Prosopis bushes, and use of community volunteers and school clubs to promote social behaviour change. The knowledge gap on malaria transmission should be addressed to minimize the impacts and enhance uptake of appropriate malaria management mechanisms. Implementing community-based framework can support significant reductions in malaria prevalence by minimizing both indoor and outdoor malaria transmissions.

Urban Malaria: Understanding its Epidemiology, Ecology, and Transmission across Seven Diverse ICEMR Network Sites

PubMed Central

Wilson, Mark L.; Krogstad, Donald J.; Arinaitwe, Emmanuel; Arevalo-Herrera, Myriam; Chery, Laura; Ferreira, Marcelo U.; Ndiaye, Daouda; Mathanga, Don P.; Eapen, Alex

2015-01-01

A major public health question is whether urbanization will transform malaria from a rural to an urban disease. However, differences about definitions of urban settings, urban malaria, and whether malaria control should differ between rural and urban areas complicate both the analysis of available data and the development of intervention strategies. This report examines the approach of the International Centers of Excellence for Malaria Research (ICEMR) to urban malaria in Brazil, Colombia, India (Chennai and Goa), Malawi, Senegal, and Uganda. Its major theme is the need to determine whether cases diagnosed in urban areas were imported from surrounding rural areas or resulted from transmission within the urban area. If infections are being acquired within urban areas, malaria control measures must be targeted within those urban areas to be effective. Conversely, if malaria cases are being imported from rural areas, control measures must be directed at vectors, breeding sites, and infected humans in those rural areas. Similar interventions must be directed differently if infections were acquired within urban areas. The hypothesis underlying the ICEMR approach to urban malaria is that optimal control of urban malaria depends on accurate epidemiologic and entomologic information about transmission. PMID:26259941

Human movement data for malaria control and elimination strategic planning.

PubMed

Pindolia, Deepa K; Garcia, Andres J; Wesolowski, Amy; Smith, David L; Buckee, Caroline O; Noor, Abdisalan M; Snow, Robert W; Tatem, Andrew J

2012-06-18

Recent increases in funding for malaria control have led to the reduction in transmission in many malaria endemic countries, prompting the national control programmes of 36 malaria endemic countries to set elimination targets. Accounting for human population movement (HPM) in planning for control, elimination and post-elimination surveillance is important, as evidenced by previous elimination attempts that were undermined by the reintroduction of malaria through HPM. Strategic control and elimination planning, therefore, requires quantitative information on HPM patterns and the translation of these into parasite dispersion. HPM patterns and the risk of malaria vary substantially across spatial and temporal scales, demographic and socioeconomic sub-groups, and motivation for travel, so multiple data sets are likely required for quantification of movement. While existing studies based on mobile phone call record data combined with malaria transmission maps have begun to address within-country HPM patterns, other aspects remain poorly quantified despite their importance in accurately gauging malaria movement patterns and building control and detection strategies, such as cross-border HPM, demographic and socioeconomic stratification of HPM patterns, forms of transport, personal malaria protection and other factors that modify malaria risk. A wealth of data exist to aid filling these gaps, which, when combined with spatial data on transport infrastructure, traffic and malaria transmission, can answer relevant questions to guide strategic planning. This review aims to (i) discuss relevant types of HPM across spatial and temporal scales, (ii) document where datasets exist to quantify HPM, (iii) highlight where data gaps remain and (iv) briefly put forward methods for integrating these datasets in a Geographic Information System (GIS) framework for analysing and modelling human population and Plasmodium falciparum malaria infection movements.

Human movement data for malaria control and elimination strategic planning

PubMed Central

2012-01-01

Recent increases in funding for malaria control have led to the reduction in transmission in many malaria endemic countries, prompting the national control programmes of 36 malaria endemic countries to set elimination targets. Accounting for human population movement (HPM) in planning for control, elimination and post-elimination surveillance is important, as evidenced by previous elimination attempts that were undermined by the reintroduction of malaria through HPM. Strategic control and elimination planning, therefore, requires quantitative information on HPM patterns and the translation of these into parasite dispersion. HPM patterns and the risk of malaria vary substantially across spatial and temporal scales, demographic and socioeconomic sub-groups, and motivation for travel, so multiple data sets are likely required for quantification of movement. While existing studies based on mobile phone call record data combined with malaria transmission maps have begun to address within-country HPM patterns, other aspects remain poorly quantified despite their importance in accurately gauging malaria movement patterns and building control and detection strategies, such as cross-border HPM, demographic and socioeconomic stratification of HPM patterns, forms of transport, personal malaria protection and other factors that modify malaria risk. A wealth of data exist to aid filling these gaps, which, when combined with spatial data on transport infrastructure, traffic and malaria transmission, can answer relevant questions to guide strategic planning. This review aims to (i) discuss relevant types of HPM across spatial and temporal scales, (ii) document where datasets exist to quantify HPM, (iii) highlight where data gaps remain and (iv) briefly put forward methods for integrating these datasets in a Geographic Information System (GIS) framework for analysing and modelling human population and Plasmodium falciparum malaria infection movements. PMID:22703541

Controlling imported malaria cases in the United States of America.

PubMed

Dembele, Bassidy; Yakubu, Abdul-Aziz

2017-02-01

We extend the mathematical malaria epidemic model framework of Dembele et al. and use it to ``capture" the 2013 Centers for Disease Control and Prevention (CDC) reported data on the 2011 number of imported malaria cases in the USA. Furthermore, we use our ``fitted" malaria models for the top 20 countries of malaria acquisition by USA residents to study the impact of protecting USA residents from malaria infection when they travel to malaria endemic areas, the impact of protecting residents of malaria endemic regions from mosquito bites and the impact of killing mosquitoes in those endemic areas on the CDC number of imported malaria cases in USA. To significantly reduce the number of imported malaria cases in USA, for each top 20 country of malaria acquisition by USA travelers, we compute the optimal proportion of USA international travelers that must be protected against malaria infection and the optimal proportion of mosquitoes that must be killed.

Situation of Sri Lanka, where autochthonous malaria is no longer a problem, and other infections dominate, such as dengue, leptospirosis and rickettsioses.

PubMed

Agampodi, Suneth; Wijerathne, Buddhika; Weerakoon, Kosala

2016-10-01

Sri Lanka achieved a major milestone in communicable disease control in 2012 by reporting zero incidence of autochthonous malaria. However, reduction of malaria was associated with concurrent increase of several tropical diseases. This review looks into the time trends and epidemiology of these communicable diseases in Sri Lanka. Reduction of malaria cases coincides with an increase of dengue, leptospirosis and rickettsioses in Sri Lanka. Although the case fatality rate of dengue has reduced and maintained below 1%, leptospirosis in clinical management is questionable. Despite having national focal points for control and prevention, these emerging diseases are completely out of control. Whether the holding back of vector control activities of malaria after a successful control programme is having an effect on emergence of other vector-borne diseases should be studied. The communicable disease control programme in Sri Lanka should be further strengthened with availability of proper and rapid diagnostic facilities. Malaria control could not be considered as a great achievement due to the fact that other emerging infectious diseases are replacing malaria.

Malaria in Uganda: challenges to control on the long road to elimination. I. Epidemiology and current control effort

PubMed Central

Yeka, Adoke; Gasasira, Anne; Mpimbaza, Arthur; Achan, Jane; Nankabirwa, Joaniter; Nsobya, Sam; Staedke, Sarah G.; Donnelly, Martin J.; Wabwire-Mangen, Fred; Talisuna, Ambrose; Dorsey, Grant; Kamya, Moses R.; Rosenthal, Philip J.

2012-01-01

In the recent past there have been several reports of successes in malaria control, leading some public health experts to conclude that Africa is witnessing an epidemiological transition, from an era of failed malaria control to progression from successful control to elimination. Successes in control have been attributed to increased international donor support leading to increased intervention coverage. However, these changes are not uniform across Africa. In Uganda, where baseline transmission is very high and intervention coverage not yet to scale, the malaria burden is not declining and has even likely increased in the last decade. In this article we present perspectives for the future for Uganda and other malaria endemic countries with high baseline transmission intensity and significant health system challenges. For these high burden areas,malaria elimination is currently not feasible, and early elimination programs are inappropriate, as they would further fragment already fragmented and inefficient malaria control systems. Rather, health impacts will be maximized by aiming to achieve universal coverage of proven interventions in the context of a strengthened health system. PMID:21756863

Malaria control in South Sudan, 2006–2013: strategies, progress and challenges

PubMed Central

2013-01-01

Background South Sudan has borne the brunt of years of chronic warfare and probably has the highest malaria burden in sub-Saharan Africa. However, effective malaria control in post-conflict settings is hampered by a multiplicity of challenges. This manuscript reports on the strategies, progress and challenges of malaria control in South Sudan and serves as an example epitome for programmes operating in similar environments and provides a window for leveraging resources. Case description To evaluate progress and challenges of the national malaria control programme an in-depth appraisal was undertaken according to the World Health Organization standard procedures for malaria programme performance review. Methodical analysis of published and unpublished documents on malaria control in South Sudan was conducted. To ensure completeness, findings of internal thematic desk assessments were triangulated in the field and updated by external review teams. Discussion and evaluation South Sudan has strived to make progress in implementing the WHO recommended malaria control interventions as set out in the 2006–2013 National Malaria Strategic Plan. The country has faced enormous programmatic constraints including infrastructure, human and financial resource and a weak health system compounded by an increasing number of refugees, returnees and internally displaced people. The findings present a platform on which to tailor an evidence-based 2014–2018 national malaria strategic plan for the country and a unique opportunity for providing a model for countries in a post-conflict situation. Conclusions The prospects for effective malaria control and elimination are huge in South Sudan. Nevertheless, strengthened coordination, infrastructure and human resource capacity, monitoring and evaluation are required. To achieve all this, allocation of adequate local funding would be critical. PMID:24160336

Current vector control challenges in the fight against malaria.

PubMed

Benelli, Giovanni; Beier, John C

2017-10-01

The effective and eco-friendly control of Anopheles vectors plays a key role in any malaria management program. Integrated Vector Management (IVM) suggests making use of the full range of vector control tools available. The strategies for IVM require novel technologies to control outdoor transmission of malaria. Despite the wide number of promising control tools tested against mosquitoes, current strategies for malaria vector control used in most African countries are not sufficient to achieve successful malaria control. The majority of National Malaria Control Programs in Africa still rely on indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs). These methods reduce malaria incidence but generally have little impact on malaria prevalence. In addition to outdoor transmission, growing levels of insecticide resistance in targeted vectors threaten the efficacy of LLINs and IRS. Larvicidal treatments can be useful, but are not recommended for rural areas. The research needed to improve the quality and delivery of mosquito vector control should focus on (i) optimization of processes and methods for vector control delivery; (ii) monitoring of vector populations and biting activity with reliable techniques; (iii) the development of effective and eco-friendly tools to reduce the burden or locally eliminate malaria and other mosquito-borne diseases; (iv) the careful evaluation of field suitability and efficacy of new mosquito control tools to prove their epidemiological impact; (v) the continuous monitoring of environmental changes which potentially affect malaria vector populations; (vi) the cooperation among different disciplines, with main emphasis on parasitology, tropical medicine, ecology, entomology, and ecotoxicology. A better understanding of behavioral ecology of malaria vectors is required. Key ecological obstacles that limit the effectiveness of vector control include the variation in mosquito behavior, development of insecticide resistance, presence of behavioral avoidance, high vector biodiversity, competitive and food web interactions, lack of insights on mosquito dispersal and mating behavior, and the impact of environmental changes on mosquito ecological traits. Overall, the trans-disciplinary cooperation among parasitologists and entomologists is crucial to ensure proper evaluation of the epidemiological impact triggered by novel mosquito vector control strategies. Copyright © 2017 Elsevier B.V. All rights reserved.

Out of the net: An agent-based model to study human movements influence on local-scale malaria transmission.

PubMed

Pizzitutti, Francesco; Pan, William; Feingold, Beth; Zaitchik, Ben; Álvarez, Carlos A; Mena, Carlos F

2018-01-01

Though malaria control initiatives have markedly reduced malaria prevalence in recent decades, global eradication is far from actuality. Recent studies show that environmental and social heterogeneities in low-transmission settings have an increased weight in shaping malaria micro-epidemiology. New integrated and more localized control strategies should be developed and tested. Here we present a set of agent-based models designed to study the influence of local scale human movements on local scale malaria transmission in a typical Amazon environment, where malaria is transmission is low and strongly connected with seasonal riverine flooding. The agent-based simulations show that the overall malaria incidence is essentially not influenced by local scale human movements. In contrast, the locations of malaria high risk spatial hotspots heavily depend on human movements because simulated malaria hotspots are mainly centered on farms, were laborers work during the day. The agent-based models are then used to test the effectiveness of two different malaria control strategies both designed to reduce local scale malaria incidence by targeting hotspots. The first control scenario consists in treat against mosquito bites people that, during the simulation, enter at least once inside hotspots revealed considering the actual sites where human individuals were infected. The second scenario involves the treatment of people entering in hotspots calculated assuming that the infection sites of every infected individual is located in the household where the individual lives. Simulations show that both considered scenarios perform better in controlling malaria than a randomized treatment, although targeting household hotspots shows slightly better performance.

Tools and Strategies for Malaria Control and Elimination: What Do We Need to Achieve a Grand Convergence in Malaria?

PubMed Central

Hemingway, Janet; Shretta, Rima; Wells, Timothy N. C.; Bell, David; Djimdé, Abdoulaye A.; Achee, Nicole; Qi, Gao

2016-01-01

Progress made in malaria control during the past decade has prompted increasing global dialogue on malaria elimination and eradication. The product development pipeline for malaria has never been stronger, with promising new tools to detect, treat, and prevent malaria, including innovative diagnostics, medicines, vaccines, vector control products, and improved mechanisms for surveillance and response. There are at least 25 projects in the global malaria vaccine pipeline, as well as 47 medicines and 13 vector control products. In addition, there are several next-generation diagnostic tools and reference methods currently in development, with many expected to be introduced in the next decade. The development and adoption of these tools, bolstered by strategies that ensure rapid uptake in target populations, intensified mechanisms for information management, surveillance, and response, and continued financial and political commitment are all essential to achieving global eradication. PMID:26934361

Tools and Strategies for Malaria Control and Elimination: What Do We Need to Achieve a Grand Convergence in Malaria?

PubMed

Hemingway, Janet; Shretta, Rima; Wells, Timothy N C; Bell, David; Djimdé, Abdoulaye A; Achee, Nicole; Qi, Gao

2016-03-01

Progress made in malaria control during the past decade has prompted increasing global dialogue on malaria elimination and eradication. The product development pipeline for malaria has never been stronger, with promising new tools to detect, treat, and prevent malaria, including innovative diagnostics, medicines, vaccines, vector control products, and improved mechanisms for surveillance and response. There are at least 25 projects in the global malaria vaccine pipeline, as well as 47 medicines and 13 vector control products. In addition, there are several next-generation diagnostic tools and reference methods currently in development, with many expected to be introduced in the next decade. The development and adoption of these tools, bolstered by strategies that ensure rapid uptake in target populations, intensified mechanisms for information management, surveillance, and response, and continued financial and political commitment are all essential to achieving global eradication.

Modelling malaria control by introduction of larvivorous fish.

PubMed

Lou, Yijun; Zhao, Xiao-Qiang

2011-10-01

Malaria creates serious health and economic problems which call for integrated management strategies to disrupt interactions among mosquitoes, the parasite and humans. In order to reduce the intensity of malaria transmission, malaria vector control may be implemented to protect individuals against infective mosquito bites. As a sustainable larval control method, the use of larvivorous fish is promoted in some circumstances. To evaluate the potential impacts of this biological control measure on malaria transmission, we propose and investigate a mathematical model describing the linked dynamics between the host-vector interaction and the predator-prey interaction. The model, which consists of five ordinary differential equations, is rigorously analysed via theories and methods of dynamical systems. We derive four biologically plausible and insightful quantities (reproduction numbers) that completely determine the community composition. Our results suggest that the introduction of larvivorous fish can, in principle, have important consequences for malaria dynamics, but also indicate that this would require strong predators on larval mosquitoes. Integrated strategies of malaria control are analysed to demonstrate the biological application of our developed theory.

PubMed Central

Raccurt, C. P.; Le Bras, M.; Ripert, C.; Cuisinier-Raynal, J. C.; Carteron, B.; Buestel, M. L.

1991-01-01

This study of imported cases of malaria, which was carried out in Bordeaux (France) in 1987-89, emphasizes the major part played by Plasmodium falciparum, especially in areas lying south of the Sahara in Africa, from where falciparum malaria is mainly imported to other countries. The study of these imported cases is strengthening our understanding of the epidemiology of malaria in relation to the country or area, whether the transmission occurs without interruptions or seasonally. The number of cases of P. falciparum per 1000 travellers (seen for vaccination against yellow fever at Bordeaux) gives an index for evaluating the risk of malaria. This risk changes with the epidemiological profile of falciparum malaria in the three major African ecosystems (rain forest, savannah, and sahelian belts), and is related to the progression of chloroquine resistance in Africa and influenced by the type of chemoprophylaxis proposed to travellers. The use of mefloquine for stays shorter than one month in Central Africa reduced the risk of malaria in 1988 and 1989, compared to 1987. [Editorial note. Recent data indicate some undesirable side-effects of mefloquine, e.g., its use during early pregnancy could lead to congenital defects.] Appropriate chemoprophylaxis and advice to travellers to areas lying south of the Sahara are therefore more and more necessary in order to arrest the increase in the number of imported falciparum malaria cases and reduce the number of serious cases, which are costly in terms of public health. PMID:2054924

Malaria in selected non-Amazonian countries of Latin America.

PubMed

Arevalo-Herrera, Myriam; Quiñones, Martha Lucia; Guerra, Carlos; Céspedes, Nora; Giron, Sandra; Ahumada, Martha; Piñeros, Juan Gabriel; Padilla, Norma; Terrientes, Zilka; Rosas, Angel; Padilla, Julio Cesar; Escalante, Ananias A; Beier, John C; Herrera, Socrates

2012-03-01

Approximately 170 million inhabitants of the American continent live at risk of malaria transmission. Although the continent's contribution to the global malaria burden is small, at least 1-1.2 million malaria cases are reported annually. Sixty percent of the malaria cases occur in Brazil and the other 40% are distributed in 20 other countries of Central and South America. Plasmodium vivax is the predominant species (74.2%) followed by P. falciparum (25.7%) and P. malariae (0.1%), and no less than 10 Anopheles species have been identified as primary or secondary malaria vectors. Rapid deforestation and agricultural practices are directly related to increases in Anopheles species diversity and abundance, as well as in the number of malaria cases. Additionally, climate changes profoundly affect malaria transmission and are responsible for malaria epidemics in some regions of South America. Parasite drug resistance is increasing, but due to bio-geographic barriers there is extraordinary genetic differentiation of parasites with limited dispersion. Although the clinical spectrum ranges from uncomplicated to severe malaria cases, due to the generally low to middle transmission intensity, features such as severe anemia, cerebral malaria and other complications appear to be less frequent than in other endemic regions and asymptomatic infections are a common feature. Although the National Malaria Control Programs (NMCP) of different countries differ in their control activities these are all directed to reduce morbidity and mortality by using strategies like health promotion, vector control and impregnate bed nets among others. Recently, international initiatives such as the Malaria Control Program in Andean-country Border Regions (PAMAFRO) (implemented by the Andean Organism for Health (ORAS) and sponsored by The Global Fund to Fight AIDS, Tuberculosis and Malaria (GFATM)) and The Amazon Network for the Surveillance of Antimalarial Drug Resistance (RAVREDA) (sponsored by the Pan American Health Organization/World Health Organization (PAHO/WHO) and several other partners), have made great investments for malaria control in the region. We describe here the current status of malaria in a non-Amazonian region comprising several countries of South and Central America participating in the Centro Latino Americano de Investigación en Malaria (CLAIM), an International Center of Excellence for Malaria Research (ICEMR) sponsored by the National Institutes of Health (NIH) National Institute of Allergy and Infectious Diseases (NIAID). Copyright © 2011 Elsevier B.V. All rights reserved.

Malaria in selected non-Amazonian countries of Latin America

PubMed Central

Arevalo-Herrera, Myriam; Quiñones, Martha Lucia; Guerra, Carlos; Céspedes, Nora; Giron, Sandra; Ahumada, Martha; Piñeros, Juan Gabriel; Padilla, Norma; Terrientes, Zilka; Rosas, Ángel; Padilla, Julio Cesar; Escalante, Ananias A.; Beier, John C.; Herrera, Socrates

2011-01-01

Approximately 170 million inhabitants of the American continent live at risk of malaria transmission. Although the continent’s contribution to the global malaria burden is small, at least 1 to 1.2 million malaria cases are reported annually. Sixty per cent of the malaria cases occur in Brazil and the other 40% are distributed in 20 other countries of Central and South America. Plasmodium vivax is the predominant species (74.2 %) followed by P. falciparum (25.7 %) and P. malariae (0.1%), and no less than 10 Anopheles species have been identified as primary or secondary malaria vectors. Rapid deforestation and agricultural practices are directly related to increases in Anopheles species diversity and abundance, as well as in the number of malaria cases. Additionally, climate changes profoundly affect malaria transmission and are responsible for malaria epidemics in some regions of South America. Parasite drug resistance is increasing, but due to bio-geographic barriers there is extraordinary genetic differentiation of parasites with limited dispersion. Although the clinical spectrum ranges from uncomplicated to severe malaria cases, due to the generally low to middle transmission intensity, features such as severe anemia, cerebral malaria and other complications appear to be less frequent than in other endemic regions and asymptomatic infections are a common feature. Although the National Malaria Control Programs (NMCP) of different countries differ in their control activities these are all directed to reduce morbidity and mortality by using strategies like health promotion, vector control and impregnate bed nets among others. Recently, international initiatives such as the Malaria Control Program in Andean-country Border Regions (PAMAFRO) (implemented by the Andean Organism for Health (ORAS) and sponsored by The Global Fund to Fight AIDS, Tuberculosis and Malaria (GFATM)) and The Amazon Network for the Surveillance of Antimalarial Drug Resistance (RAVREDA) (sponsored by the Pan American Health Organization/World Health Organization (PAHO/WHO) and several other partners), have made great investments for malaria control in the region. We describe here the current status of malaria in a non-Amazonian region comprising several countries of South and Central America participating in the Centro Latino Americano de Investigación en Malaria (CLAIM), an International Center of Excellence for Malaria Research (ICEMR) sponsored by the National Institutes of Health’s (NIH) National Institute of Allergy and Infectious Diseases (NIAID). PMID:21741349

Funding for malaria control 2006-2010: a comprehensive global assessment.

PubMed

Pigott, David M; Atun, Rifat; Moyes, Catherine L; Hay, Simon I; Gething, Peter W

2012-07-28

The last decade has seen a dramatic increase in international and domestic funding for malaria control, coupled with important declines in malaria incidence and mortality in some regions of the world. As the ongoing climate of financial uncertainty places strains on investment in global health, there is an increasing need to audit the origin, recipients and geographical distribution of funding for malaria control relative to populations at risk of the disease. A comprehensive review of malaria control funding from international donors, bilateral sources and national governments was undertaken to reconstruct total funding by country for each year 2006 to 2010. Regions at risk from Plasmodium falciparum and/or Plasmodium vivax transmission were identified using global risk maps for 2010 and funding was assessed relative to populations at risk. Those nations with unequal funding relative to a regional average were identified and potential explanations highlighted, such as differences in national policies, government inaction or donor neglect. US$8.9 billion was disbursed for malaria control and elimination programmes over the study period. Africa had the largest levels of funding per capita-at-risk, with most nations supported primarily by international aid. Countries of the Americas, in contrast, were supported typically through national government funding. Disbursements and government funding in Asia were far lower with a large variation in funding patterns. Nations with relatively high and low levels of funding are discussed. Global funding for malaria control is substantially less than required. Inequity in funding is pronounced in some regions particularly when considering the distinct goals of malaria control and malaria elimination. Efforts to sustain and increase international investment in malaria control should be informed by evidence-based assessment of funding equity.

Funding for malaria control 2006–2010: A comprehensive global assessment

PubMed Central

2012-01-01

Background The last decade has seen a dramatic increase in international and domestic funding for malaria control, coupled with important declines in malaria incidence and mortality in some regions of the world. As the ongoing climate of financial uncertainty places strains on investment in global health, there is an increasing need to audit the origin, recipients and geographical distribution of funding for malaria control relative to populations at risk of the disease. Methods A comprehensive review of malaria control funding from international donors, bilateral sources and national governments was undertaken to reconstruct total funding by country for each year 2006 to 2010. Regions at risk from Plasmodium falciparum and/or Plasmodium vivax transmission were identified using global risk maps for 2010 and funding was assessed relative to populations at risk. Those nations with unequal funding relative to a regional average were identified and potential explanations highlighted, such as differences in national policies, government inaction or donor neglect. Results US$8.9 billion was disbursed for malaria control and elimination programmes over the study period. Africa had the largest levels of funding per capita-at-risk, with most nations supported primarily by international aid. Countries of the Americas, in contrast, were supported typically through national government funding. Disbursements and government funding in Asia were far lower with a large variation in funding patterns. Nations with relatively high and low levels of funding are discussed. Conclusions Global funding for malaria control is substantially less than required. Inequity in funding is pronounced in some regions particularly when considering the distinct goals of malaria control and malaria elimination. Efforts to sustain and increase international investment in malaria control should be informed by evidence-based assessment of funding equity. PMID:22839432

Distribution and prevalence of knemidokoptic mange in Hawai`i `Amakihi on the island of Hawaii

USGS Publications Warehouse

Gaudioso, Jacqueline; LaPointe, Dennis; Atkinson, Carter T.; Apelgren, Chloe

2014-01-01

Knemidokoptic mange was first observed on two Hawai‘i ‘Amakihi (Hemignathus virens) mist netted in Manuka Natural Area Reserve (NAR) on the Island of Hawai‘i in June 2007. Microscopic examination of skin scrapings from lesions of the infested individuals revealed the scaley-leg mite, Knemidokoptes jamaicensis. Continued surveillance at Manuka NAR (2007-2009) documented a 24% (15/63) prevalence of mange among Hawai‘i ‘Amakihi distributed from coastal habitat to 1,500 m above sea level (asl). From 2012-2014, we conducted an island-wide survey of wild passerine birds from several leeward sites (Manuka NAR, Kahuku Unit of Hawai‘i Volcanoes National Park (HAVO), Pu‘u Wa‘awa‘a Forest Bird Sanctuary, and Kipahoehoe NAR) and windward sites (Hakalau Forest National Wildlife Refuge, ‘Ᾱinahou Ranch of HAVO, Malama Ki Forest Reserve, and Keauohana Forest Reserve) to determine the current distribution and host range of knemidokoptic mange. We also determined the prevalence of malaria in Hawai‘i ‘Amakihi populations where mange was present and treated a subset of infested Hawai‘i ‘Amakihi mange with a single, topical dose of moxidectin. We mist netted and examined a total of 1,734 passerines, including 738 Hawai‘i ‘Amakihi. Mange was present in Hawai‘i ‘Amakihi at Manuka NAR (595 and 305 m asl), Kahuku Ranch Unit of HAVO (Glover site: 1,201 m asl and Kipuka Akala site: 1,532 m asl), Malama Ki Forest Reserve and Keauohana Forest Reserve (293 m asl). No other passerine birds (n = 995) were infected. Mange prevalence ranged from a high of 69% (40/58) in Keauohana Forest Reserve to a low of 2% (1/65) in the Kahuku Ranch Unit of HAVO (Kipuka Akala). At Manuka NAR prevalence had decreased from 26% in 2010 to 10% (7/81) in 2012–2014. We found no significant relationship between the prevalence of mange and the prevalence of avian malaria in mesic habitats at Manuka NAR (P = 0.59 (FET, n = 81)), but there was a significant association between the prevalence of mange and the prevalence of malaria in lowland wet forests in Puna Forest Reserves (P < 0.01 (FET, n = 72)). This apparent association may be a reflection of the high prevalence of malaria (>80%) in these areas. There was no difference in the frequency of recapture of birds that were infested versus un-infested at first capture at our long-term sites (Manuka NAR and Puna sites) (χ2(1, n = 227) = 1.51, P = 0.22, but when all sites with mange present were pooled, there was a significant difference in the frequency of recaptures between infested and un-infested birds (χ2(1, n = 424) = 7.13, P = 0.01). There was a significant association between parasitemia level (per 10,000 RBCs) and the ranked stage of mange present in infested individuals. We treated 24 Hawai‘i ‘Amakihi with moxidectin and upon recapture (n = 2), found a reduction in both the size and stage of mange lesions, such that a single dose, topical treatment of moxidectin appears to be an effective treatment for knemidokoptic mange in wild populations. Our results suggest that knemidokoptic mange is currently limited to Hawai‘i ‘Amakihi and prevalent in low elevation sites on both the windward and leeward sides of the island.

[Evaluation of effect of prevention and control system for imported falciparum malaria in Hanjiang District].

PubMed

She, Guo-lin; Ma, Yu-Cai; Wang, Fu-biao

2013-08-01

To analyze the current situation of the comprehensive prevention and control system for imported falciparum malaria in Hanjiang District and evaluate its effect. According to the Management Scheme on Control of Imported Falciparum Malaria in Yangzhou City, the comprehensive prevention and control system for imported falciparum malaria was implemented, and the relevant malaria data were collected and analyzed statistically. The data included plasmodium blood test ratio of fever patients among exported labors and those returned, the ratio of laboratory-confirmed cases among all reported cases of falciparum malaria, the ratio of falciparum malaria patients who received the standard treatment within 24 hours after onset, etc from 2010 to 2012. After the implementation of the comprehensive prevention and control system, the confirmation ratio of falciparum malaria cases within 24 hours following first visit has reached 60.47%, the average time from first visit to confirmation has shortened to 1.8 d, and the average time from onset to confirmation has shortened to 3.7 d. The health education coverage ratio was 100%, the health knowledge awareness ratio was 95.56%, the ratio of patients seeking treatment on own initiative was 100%, the laboratory-confirmed ratio was 100%, and the ratio of standard treatment after malaria diagnosis was 100%. The comprehensive prevention and control system carried out by Hanjiang District has made remarkable achievements.

Framework for Evaluating the Health Impact of the Scale-Up of Malaria Control Interventions on All-Cause Child Mortality in Sub-Saharan Africa

PubMed Central

Yé, Yazoume; Eisele, Thomas P.; Eckert, Erin; Korenromp, Eline; Shah, Jui A.; Hershey, Christine L.; Ivanovich, Elizabeth; Newby, Holly; Carvajal-Velez, Liliana; Lynch, Michael; Komatsu, Ryuichi; Cibulskis, Richard E.; Moore, Zhuzhi; Bhattarai, Achuyt

2017-01-01

Abstract. Concerted efforts from national and international partners have scaled up malaria control interventions, including insecticide-treated nets, indoor residual spraying, diagnostics, prompt and effective treatment of malaria cases, and intermittent preventive treatment during pregnancy in sub-Saharan Africa (SSA). This scale-up warrants an assessment of its health impact to guide future efforts and investments; however, measuring malaria-specific mortality and the overall impact of malaria control interventions remains challenging. In 2007, Roll Back Malaria's Monitoring and Evaluation Reference Group proposed a theoretical framework for evaluating the impact of full-coverage malaria control interventions on morbidity and mortality in high-burden SSA countries. Recently, several evaluations have contributed new ideas and lessons to strengthen this plausibility design. This paper harnesses that new evaluation experience to expand the framework, with additional features, such as stratification, to examine subgroups most likely to experience improvement if control programs are working; the use of a national platform framework; and analysis of complete birth histories from national household surveys. The refined framework has shown that, despite persisting data challenges, combining multiple sources of data, considering potential contributions from both fundamental and proximate contextual factors, and conducting subnational analyses allows identification of the plausible contributions of malaria control interventions on malaria morbidity and mortality. PMID:28990923

Implementing Impact Evaluations of Malaria Control Interventions: Process, Lessons Learned, and Recommendations

PubMed Central

Hershey, Christine L.; Bhattarai, Achuyt; Florey, Lia S.; McElroy, Peter D.; Nielsen, Carrie F.; Yé, Yazoume; Eckert, Erin; Franca-Koh, Ana Cláudia; Shargie, Estifanos; Komatsu, Ryuichi; Smithson, Paul; Thwing, Julie; Mihigo, Jules; Herrera, Samantha; Taylor, Cameron; Shah, Jui; Mouzin, Eric; Yoon, Steven S.; Salgado, S. René

2017-01-01

Abstract. As funding for malaria control increased considerably over the past 10 years resulting in the expanded coverage of malaria control interventions, so did the need to measure the impact of these investments on malaria morbidity and mortality. Members of the Roll Back Malaria (RBM) Partnership undertook impact evaluations of malaria control programs at a time when there was little guidance in terms of the process for conducting an impact evaluation of a national-level malaria control program. The President’s Malaria Initiative (PMI), as a member of the RBM Partnership, has provided financial and technical support for impact evaluations in 13 countries to date. On the basis of these experiences, PMI and its partners have developed a streamlined process for conducting the evaluations with a set of lessons learned and recommendations. Chief among these are: to ensure country ownership and involvement in the evaluations; to engage stakeholders throughout the process; to coordinate evaluations among interested partners to avoid duplication of efforts; to tailor the evaluation to the particular country context; to develop a standard methodology for the evaluations and a streamlined process for completion within a reasonable time; and to develop tailored dissemination products on the evaluation for a broad range of stakeholders. These key lessons learned and resulting recommendations will guide future impact evaluations of malaria control programs and other health programs. PMID:28990921

Altitudinal migration and the future of an iconic Hawaiian honeycreeper in response to climate change and management

USGS Publications Warehouse

Guillaumet, Alban; Kuntz, Wendy A.; Samuel, Michael D.; Paxton, Eben H.

2017-01-01

Altitudinal movement by tropical birds to track seasonally variable resources can move them from protected areas to areas of increased vulnerability. In Hawaiʻi, historical reports suggest that many Hawaiian honeycreepers such as the ‘I‘iwi (Drepanis coccinea) once undertook seasonal migrations, but the existence of such movements today is unclear. Because Hawaiian honeycreepers are highly susceptible to avian malaria, currently minimal in high-elevation forests, understanding the degree to which honeycreepers visit lower elevation forests may be critical to predict the current impact of malaria on population dynamics and how susceptible bird populations may respond to climate change and mitigation scenarios. Using radio telemetry data, we demonstrate for the first time that a large fraction of breeding adult and juvenile ‘I‘iwi originating from an upper-elevation (1,920 m) population at Hakalau Forest National Wildlife Refuge exhibit post-breeding movements well below the upper elevational limit for mosquitoes. Bloom data suggest seasonal variation in floral resources is the primary driver of seasonal movement for ‘I‘iwi. To understand the demographic implications of such movement, we developed a spatial individual-based model calibrated using previously published and original data. ʻI‘iwi dynamics were simulated backward in time, to estimate population levels in the absence of avian malaria, and forward in time, to assess the impact of climate warming as well as two potential mitigation actions. Even in disease-free ‘refuge’ populations, we found that breeding densities failed to reach the estimated carrying capacity, suggesting the existence of a seasonal “migration load” as a result of travel to disease-prevalent areas. We predict that ‘I‘iwi may be on the verge of extinction in 2100, with the total number of pairs reaching only ~ 0.2–12.3% of the estimated pre-malaria density, based on an optimistic climate change scenario. The probability of extinction of ‘I‘iwi populations, as measured by population estimates for 2100, is strongly related to their estimated migration propensity. Long-term conservation strategies likely will require a multi-pronged response including a reduction of malaria threats, habitat restoration and continued landscape-level access to seasonally variable nectar resources.

Malaria control aimed at the entire population in KwaZulu-Natal negates the need for policies to prevent malaria in pregnancy.

PubMed

Tsoka-Gwegweni, J M; Kleinschmidt, I

2013-01-24

South Africa has no policy to prevent malaria in pregnancy, despite the adverse effects of the disease in pregnancy. However, malaria control measures consisting of indoor residual spraying and specific antimalarial treatment have been in place since the 1970s. Information on the burden of malaria in pregnancy in South Africa is needed to indicate whether a specific policy for malaria prevention in pregnancy is necessary. To determine the burden of malaria in pregnancy in KwaZulu-Natal (KZN) province, South Africa. Pregnant women were enrolled at their first antenatal care visit to three health facilities in Umkhanyakude health district in northern KZN during May 2004 - September 2005 and followed up until delivery. Data collection included demographic details, current and previous malaria infection during pregnancy, haemoglobin concentrations and birth outcomes. Of the 1 406 study participants, more than a quarter were younger than 20 years of age, and more than 90% were unemployed and unmarried. Although 33.2% of the women were anaemic, this was not related to malaria. The prevalence and incidence of malaria were very low, and low birth weight was only weakly associated with malaria (1/10). The low burden of malaria in these pregnant women suggests that they have benefited from malaria control strategies in the study area. The implication is that additional measures specific for malaria prevention in pregnancy are not required. However, ongoing monitoring is needed to ensure that malaria prevalence remains low.

Aggressive active case detection: a malaria control strategy based on the Brazilian model.

PubMed

Macauley, Cameron

2005-02-01

Since 1996, the Brazilian Ministry of Health has adopted a malaria control strategy known as aggressive active case detection (AACD) in which most or all members of every community are tested and treated for malaria on a monthly basis. The strategy attempts to identify and treat cases of asymptomatic malaria, which, if untreated, continue to transmit the infection. Malaria remains uncontrolled because almost all health care systems in the world rely on passive case detection: the treatment of only symptomatic cases of malaria. Research has shown conclusively that asymptomatic cases exist in any population where malaria transmission is stable and incidence is high: therefore passive case detection simply will not succeed in breaking the cycle of transmission. Numerous case studies show that malaria has been successfully controlled on a regional or national level by mass blood surveys. AACD is an effective malaria control strategy if used in conjunction with other methods, especially when (1) an effective treatment exists, (2) influx of potential carriers of the infection can be monitored, and (3) people are inclined to cooperate with monthly blood testing. AACD requires access to rapid diagnostic tests (RDTs), microscopy supplies, extensive human resources, and prompt, affordable, and effective treatment. AACD is compared to PCD in terms of clinical efficacy and cost effectiveness in a case study of malaria in the Brazilian Yanomami Indians. Where it is feasible, AACD could drastically reduce the incidence of malaria and should be an integral part of the World Health Organization's Roll Back Malaria strategy.

Using Rainfall and Temperature Data in the Evaluation of National Malaria Control Programs in Africa.

PubMed

Thomson, Madeleine C; Ukawuba, Israel; Hershey, Christine L; Bennett, Adam; Ceccato, Pietro; Lyon, Bradfield; Dinku, Tufa

2017-09-01

Since 2010, the Roll Back Malaria (RBM) Partnership, including National Malaria Control Programs, donor agencies (e.g., President's Malaria Initiative and Global Fund), and other stakeholders have been evaluating the impact of scaling up malaria control interventions on all-cause under-five mortality in several countries in sub-Saharan Africa. The evaluation framework assesses whether the deployed interventions have had an impact on malaria morbidity and mortality and requires consideration of potential nonintervention influencers of transmission, such as drought/floods or higher temperatures. Herein, we assess the likely effect of climate on the assessment of the impact malaria interventions in 10 priority countries/regions in eastern, western, and southern Africa for the President's Malaria Initiative. We used newly available quality controlled Enhanced National Climate Services rainfall and temperature products as well as global climate products to investigate likely impacts of climate on malaria evaluations and test the assumption that changing the baseline period can significantly impact on the influence of climate in the assessment of interventions. Based on current baseline periods used in national malaria impact assessments, we identify three countries/regions where current evaluations may overestimate the impact of interventions (Tanzania, Zanzibar, Uganda) and three countries where current malaria evaluations may underestimate the impact of interventions (Mali, Senegal and Ethiopia). In four countries (Rwanda, Malawi, Mozambique, and Angola) there was no strong difference in climate suitability for malaria in the pre- and post-intervention period. In part, this may be due to data quality and analysis issues.

Conservation Efforts and Malaria in the Brazilian Amazon

PubMed Central

Hahn, Micah B.; Olson, Sarah H.; Vittor, Amy Y.; Barcellos, Christovam; Patz, Jonathan A.; Pan, William

2014-01-01

We respond to Valle and Clark,1 who assert that “conservation efforts may increase malaria burden in the Brazilian Amazon,” because the relationship between forest cover and malaria incidence was stronger than the effect of the deforestation rate.1 We contend that their conclusion is flawed because of limitations in their methodology that we discuss in detail. Most important are the exclusion of one-half the original data without a discussion of selection bias, the lack of model adjustment for either population growth or migration, and the crude classifications of land cover and protected areas that lead to aggregation bias.1 Of greater significance, we stress the need for caution in the interpretation of data that could have profound effects on regional land use decisions. PMID:24277787

Re-imagining malaria--a platform for reflections to widen horizons in malaria control.

PubMed

Hausmann-Muela, Susanna; Eckl, Julian

2015-04-24

Ongoing political-economic discussions that take stock of social and societal determinants of health present an opportunity for productive dialogue on why current approaches to malaria control and elimination need to be broadened, and how this may be accomplished. They invite us, for example, to look beyond malaria as a disease, to appreciate the experiences of malaria-afflicted populations, to transcend techno-centric approaches, to investigate social conflicts around malaria, to give voice to the communities engaged in bottom-up approaches, and to revisit lessons learned in the past. While contributions from all disciplines are invited to this discussion, social scientists are particularly encouraged to participate. They have struggled in the past to find an appropriate platform within the malaria community that provides them the opportunity to address researchers from other disciplines, malaria practitioners, and policy makers. The Malaria Journal's new thematic series on 're-imagining malaria' offers them this opportunity. The goal of the series is to encourage transdisciplinary thinking, to stimulate discussion, to promote constructive criticism, and to gather overlooked experiences that help to reflect on implicit assumptions. Overall it aims at widening horizons in malaria control.

Urban Malaria: Understanding its Epidemiology, Ecology, and Transmission Across Seven Diverse ICEMR Network Sites.

PubMed

Wilson, Mark L; Krogstad, Donald J; Arinaitwe, Emmanuel; Arevalo-Herrera, Myriam; Chery, Laura; Ferreira, Marcelo U; Ndiaye, Daouda; Mathanga, Don P; Eapen, Alex

2015-09-01

A major public health question is whether urbanization will transform malaria from a rural to an urban disease. However, differences about definitions of urban settings, urban malaria, and whether malaria control should differ between rural and urban areas complicate both the analysis of available data and the development of intervention strategies. This report examines the approach of the International Centers of Excellence for Malaria Research (ICEMR) to urban malaria in Brazil, Colombia, India (Chennai and Goa), Malawi, Senegal, and Uganda. Its major theme is the need to determine whether cases diagnosed in urban areas were imported from surrounding rural areas or resulted from transmission within the urban area. If infections are being acquired within urban areas, malaria control measures must be targeted within those urban areas to be effective. Conversely, if malaria cases are being imported from rural areas, control measures must be directed at vectors, breeding sites, and infected humans in those rural areas. Similar interventions must be directed differently if infections were acquired within urban areas. The hypothesis underlying the ICEMR approach to urban malaria is that optimal control of urban malaria depends on accurate epidemiologic and entomologic information about transmission. © The American Society of Tropical Medicine and Hygiene.

Environmental, entomological, socioeconomic and behavioural risk factors for malaria attacks in Amerindian children of Camopi, French Guiana

PubMed Central

2011-01-01

Background Malaria is a major health issue in French Guiana. Amerindian communities remain the most affected. A previous study in Camopi highlighted the predominant role of environmental factors in the occurrence of malaria. However, all parameters involved in the transmission were not clearly identified. A new survey was conducted in order to clarify the risk factors for the presence of malaria cases in Camopi. Methods An open cohort of children under seven years of age was set up on the basis of biologically confirmed malaria cases for the period 2001-2009. Epidemiological and observational environmental data were collected using two structured questionnaires. Data were analysed with a multiple failures multivariate Cox model. The influence of climate and the river level on malaria incidence was evaluated by time-series analysis. Relationships between Anopheles darlingi human biting rates and malaria incidence rates were estimated using Spearman's rank correlation. Results The global annual incidence over the nine-year period was 238 per 1,000 for Plasmodium falciparum, 514 per 1,000 for Plasmodium visa and 21 per 1,000 for mixed infections. The multivariate survival analysis associated higher malaria incidence with living on the Camopi riverside vs. the Oyapock riverside, far from the centre of the Camopi hamlet, in a home with numerous occupants and going to sleep late. On the contrary, living in a house cleared of all vegetation within 50 m and at high distance of the forest were associated with a lower risk. Meteorological and hydrological characteristics appeared to be correlated with malaria incidence with different lags. Anopheles darlingi human biting rate was also positively correlated to incident malaria in children one month later. Conclusions Malaria incidence in children remains high in young children despite the appearance of immunity in children around three years of age. The closeness environment but also the meteorological parameters play an important role in malaria transmission among children under seven years of age in Camopi. PMID:21861885

Factors influencing malaria control policy-making in Kenya, Uganda and Tanzania.

PubMed

Mutero, Clifford M; Kramer, Randall A; Paul, Christopher; Lesser, Adriane; Miranda, Marie Lynn; Mboera, Leonard E G; Kiptui, Rebecca; Kabatereine, Narcis; Ameneshewa, Birkinesh

2014-08-08

Policy decisions for malaria control are often difficult to make as decision-makers have to carefully consider an array of options and respond to the needs of a large number of stakeholders. This study assessed the factors and specific objectives that influence malaria control policy decisions, as a crucial first step towards developing an inclusive malaria decision analysis support tool (MDAST). Country-specific stakeholder engagement activities using structured questionnaires were carried out in Kenya, Uganda and Tanzania. The survey respondents were drawn from a non-random purposeful sample of stakeholders, targeting individuals in ministries and non-governmental organizations whose policy decisions and actions are likely to have an impact on the status of malaria. Summary statistics across the three countries are presented in aggregate. Important findings aggregated across countries included a belief that donor preferences and agendas were exerting too much influence on malaria policies in the countries. Respondents on average also thought that some relevant objectives such as engaging members of parliament by the agency responsible for malaria control in a particular country were not being given enough consideration in malaria decision-making. Factors found to influence decisions regarding specific malaria control strategies included donor agendas, costs, effectiveness of interventions, health and environmental impacts, compliance and/acceptance, financial sustainability, and vector resistance to insecticides. Malaria control decision-makers in Kenya, Uganda and Tanzania take into account health and environmental impacts as well as cost implications of different intervention strategies. Further engagement of government legislators and other policy makers is needed in order to increase funding from domestic sources, reduce donor dependence, sustain interventions and consolidate current gains in malaria.

Use of remote sensing to identify spatial risk factors for malaria in a region of declining transmission: a cross-sectional and longitudinal community survey.

PubMed

Moss, William J; Hamapumbu, Harry; Kobayashi, Tamaki; Shields, Timothy; Kamanga, Aniset; Clennon, Julie; Mharakurwa, Sungano; Thuma, Philip E; Glass, Gregory

2011-06-10

The burden of malaria has decreased dramatically within the past several years in parts of sub-Saharan Africa. Further malaria control will require targeted control strategies based on evidence of risk. The objective of this study was to identify environmental risk factors for malaria transmission using remote sensing technologies to guide malaria control interventions in a region of declining burden of malaria. Satellite images were used to construct a sampling frame for the random selection of households enrolled in prospective longitudinal and cross-sectional surveys of malaria parasitaemia in Southern Province, Zambia. A digital elevation model (DEM) was derived from the Shuttle Radar Topography Mission version 3 DEM and used for landscape characterization, including landforms, elevation, aspect, slope, topographic wetness, topographic position index and hydrological models of stream networks. A total of 768 individuals from 128 randomly selected households were enrolled over 21 months, from the end of the rainy season in April 2007 through December 2008. Of the 768 individuals tested, 117 (15.2%) were positive by malaria rapid diagnostic test (RDT). Individuals residing within 3.75 km of a third order stream were at increased risk of malaria. Households at elevations above the baseline elevation for the region were at decreasing risk of having RDT-positive residents. Households where new infections occurred were overlaid on a risk map of RDT positive households and incident infections were more likely to be located in high-risk areas derived from prevalence data. Based on the spatial risk map, targeting households in the top 80th percentile of malaria risk would require malaria control interventions directed to only 24% of the households. Remote sensing technologies can be used to target malaria control interventions in a region of declining malaria transmission in southern Zambia, enabling a more efficient use of resources for malaria elimination.

The Role of Malaria Microscopy Training and Refresher Training Courses in Malaria Control Program in Iran during 2001 - 2011.

PubMed

Nateghpour, M; Edrissian, Ghh; Raeisi, A; Motevalli-Haghi, A; Farivar, L; Mohseni, Gh; Rahimi-Froushani, A

2012-01-01

Malaria is still one of the most important infectious diseases in the world. The disease also is a public health problem in south and southeast of Iran. This study programmed to show the correlation between regular malaria microscopy training and refresher training courses and control of malaria in Iran. Three types of training courses were conducted in this programme including; five - day, ten - day and bimonthly training courses. Each of the training courses contained theoretical and practical sections and training impact was evaluated by practical examination and multiple-choice quizzes through pre and post tests. Distribution pattern of the participants in the training and refresher training courses showed that the most participants were from Sistan & Baluchistan and Hormozgan provinces where malaria is endemic and most cases of the infection come out from these malarious areas. A total of 695 identified individuals were participated in the training courses. A significant conversely correlation was found between conducting malaria microscopy training courses and annual malaria cases in Iran. Conducting a suitable programme for malaria microscopy training and refresher training plays an important role in the control of malaria in endemic areas. Obviously, the decrease of malaria cases in Iran has been achieved due to some activities that malaria diagnosis training was one of them.

Eliminating malaria in Malaysia: the role of partnerships between the public and commercial sectors in Sabah.

PubMed

Sanders, Kelly C; Rundi, Christina; Jelip, Jenarun; Rashman, Yusof; Smith Gueye, Cara; Gosling, Roly D

2014-01-21

Countries in the Asia Pacific region have made great progress in the fight against malaria; several are rapidly approaching elimination. However, malaria control programmes operating in elimination settings face substantial challenges, particularly around mobile migrant populations, access to remote areas and the diversity of vectors with varying biting and breeding behaviours. These challenges can be addressed through subnational collaborations with commercial partners, such as mining or plantation companies, that can conduct or support malaria control activities to cover employees. Such partnerships can be a useful tool for accessing high-risk populations and supporting malaria elimination goals. This observational qualitative case study employed semi-structured key informant interviews to describe partnerships between the Malaysian Malaria Control Programme (MCP), and private palm oil, rubber and acacia plantations in the state of Sabah. Semi-structured interview guides were used to examine resource commitments, incentives, challenges, and successes of the collaborations. Interviews with workers from private plantations and the state of Sabah MCP indicated that partnerships with the commercial sector had contributed to decreases in incidence at plantation sites since 1991. Several plantations contribute financial and human resources toward malaria control efforts and all plantations frequently communicate with the MCP to help monitor the malaria situation on-site. Management of partnerships between private corporations and government entities can be challenging, as prioritization of malaria control may change with annual profits or arrival of new management. Partnering with the commercial sector has been an essential operational strategy to support malaria elimination in Sabah. The successes of these partnerships rely on a common understanding that elimination will be a mutually beneficial outcome for employers and the general public. Best practices included consistent communication, developing government-staffed subsector offices for malaria control on-site, engaging commercial plantations to provide financial and human resources for malaria control activities, and the development of new worker screening programmes. The successes and challenges associated with partnerships between the public and commercial sector can serve as an example for other malaria-eliminating countries with large plantation sectors, and may also be applied to other sectors that employ migrant workers or have commercial enterprises in hard to reach areas.

Changes in malaria morbidity and mortality in Mpumalanga Province, South Africa (2001- 2009): a retrospective study

PubMed Central

2012-01-01

Background Malaria remains a serious epidemic threat in Mpumalanga Province. In order to appropriately target interventions to achieve substantial reduction in the burden of malaria and ultimately eliminate the disease, there is a need to track progress of malaria control efforts by assessing the time trends and evaluating the impact of current control interventions. This study aimed to assess the changes in the burden of malaria in Mpumalanga Province during the past eight malaria seasons (2001/02 to 2008/09) and whether indoor residual spraying (IRS) and climate variability had an effect on these changes. Methods This is a descriptive retrospective study based on the analysis of secondary malaria surveillance data (cases and deaths) in Mpumalanga Province. Data were extracted from the Integrated Malaria Information System. Time series model (Autoregressive Integrated Moving Average) was used to assess the association between climate and malaria. Results Within the study period, a total of 35,191 cases and 164 deaths due to malaria were notified in Mpumalanga Province. There was a significant decrease in the incidence of malaria from 385 in 2001/02 to 50 cases per 100,000 population in 2008/09 (P < 0.005). The incidence and case fatality (CFR) rates for the study period were 134 cases per 100,000 and 0.54%, respectively. Mortality due to malaria was lower in infants and children (CFR < 0.5%) and higher in those >65 years, with the mean CFR of 2.1% as compared to the national target of 0.5%. A distinct seasonal transmission pattern was found to be significantly related to changes in rainfall patterns (P = 0.007). A notable decline in malaria case notification was observed following apparent scale-up of IRS coverage from 2006/07 to 2008/09 malaria seasons. Conclusions Mpumalanga Province has achieved the goal of reducing malaria morbidity and mortality by over 70%, partly as a result of scale-up of IRS intervention in combination with other control strategies. These results highlight the need to continue with IRS together with other control strategies until interruption in local malaria transmission is completely achieved. However, the goal to eliminate malaria as a public health problem requires efforts to be directed towards the control of imported malaria cases; development of strategies to interrupt local transmission; and maintaining high quality surveillance and reporting system. PMID:22239855

Application of optimal control strategies to HIV-malaria co-infection dynamics

NASA Astrophysics Data System (ADS)

Fatmawati; Windarto; Hanif, Lathifah

2018-03-01

This paper presents a mathematical model of HIV and malaria co-infection transmission dynamics. Optimal control strategies such as malaria preventive, anti-malaria and antiretroviral (ARV) treatments are considered into the model to reduce the co-infection. First, we studied the existence and stability of equilibria of the presented model without control variables. The model has four equilibria, namely the disease-free equilibrium, the HIV endemic equilibrium, the malaria endemic equilibrium, and the co-infection equilibrium. We also obtain two basic reproduction ratios corresponding to the diseases. It was found that the disease-free equilibrium is locally asymptotically stable whenever their respective basic reproduction numbers are less than one. We also conducted a sensitivity analysis to determine the dominant factor controlling the transmission. sic reproduction numbers are less than one. We also conducted a sensitivity analysis to determine the dominant factor controlling the transmission. Then, the optimal control theory for the model was derived analytically by using Pontryagin Maximum Principle. Numerical simulations of the optimal control strategies are also performed to illustrate the results. From the numerical results, we conclude that the best strategy is to combine the malaria prevention and ARV treatments in order to reduce malaria and HIV co-infection populations.

How molecular epidemiology studies can support the National Malaria Control Program in Papua New Guinea.

PubMed

Koepfli, Cristian; Barry, Alyssa; Javati, Sarah; Timinao, Lincoln; Nate, Elma; Mueller, Ivo; Barnadas, Celine

2014-01-01

Papua New Guinea (PNG) is undertaking intensified efforts to control malaria. The National Malaria Control Program aims to reduce the burden of disease by large-scale distribution of insecticide-treated bednets, improved diagnosis and implementation of new treatments. A scientific program monitoring the effect of these interventions, including molecular epidemiology studies, closely accompanies the program. Laboratory assays have been developed in (or transferred to) PNG to measure prevalence of infection and intensity of transmission as well as potential resistance to currently used drugs. These assays help to assess the impact of the National Malaria Control Program, and they reveal a much clearer picture of malaria epidemiology in PNG. In addition, analysis of the geographical clustering of parasites aids in selecting areas where intensified control will be most successful. This paper gives an overview of current research and recently completed studies in the molecular epidemiology of malaria conducted in Papua New Guinea.

Comparative susceptibility of introduced forest-dwelling mosquitoes in Hawai'i to avian malaria, Plasmodium relictum

USGS Publications Warehouse

Lapointe, D.A.; Goff, M.L.; Atkinson, C.T.

2005-01-01

To identify potential vectors of avian malaria in Hawaiian native forests, the innate susceptibility of Aedes albopictus, Wyeomyia mitchellii, and Culex quinquefasciatus from 3 geographical sites along an altitudinal gradient was evaluated using local isolates of Plasmodium relictum. Mosquitoes were dissected 5-8 and 9-13 days postinfective blood meal and microscopically examined for oocysts and salivary-gland sporozoites. Sporogony was completed in all 3 species, but prevalence between species varied significantly. Oocysts were detected in 1-2% and sporozoites in 1-7% of Aedes albopictus that fed on infected ducklings. Wyeomyia mitchellii was slightly more susceptible, with 7-19% and 7% infected with oocysts and sporozoites, respectively. In both species, the median oocyst number was 5 or below. This is only the second Wyeomyia species reported to support development of a malarial parasite. Conversely, Culex quinquefasciatus from all 3 sites proved very susceptible. Prevalence of oocysts and sporozoites consistently exceeded 70%, regardless of gametocytemia or origin of the P. relictum isolate. In trials for which a maximum 200 oocysts were recorded, the median number of oocysts ranged from 144 to 200. It was concluded that Culex quinquefasciatus is the primary vector of avian malaria in Hawai'i. ?? American Society of Parasitologists 2005.

[Malaria and HIV infection: clinical and biological aspects at Donka National Hospital in Conakry, Guinea].

PubMed

Bald, I; Camara, A; Baldé, O; Magassouba, N F; Bah, M S; Makanéra, A; Gamy, E P

2010-08-01

Malaria and HIV/AIDS are two of the most widespread infectious diseases encountered in sub-Saharan Africa. Even minor interactions between these two diseases could have substantial effects on public health. The purpose of this study was to investigate associations between malaria and HIV infection. Study was carried out over an 8-month period (April 1, 2003 to November 30, 2003) in the Tropical and Infectious Diseases Department of the Donka National Hospital in Conakry, Guinea. A total of 89 malaria patients including 41 cases with HIV infection and 48 controls without HIV infection were included. All patients were hospitalized during the study and provided informed consent. Results showed that malaria affected all age groups in the same proportion. Mean patient age was 34 years (range, 15 and 76 years). Males were more frequently infected with a sex ratio of 1.05. The average number of malaria episodes was higher in cases (malaria with HIV-infection than in controls (malaria without HIV infection). Hyperthermia was observed in most cases (68.29%) and controls (77.08%). Severe anemia was observed in 26.82% of cases versus 10.41% of controls. Low parasite density was observed in 73.17% of cases as compared to 68.75% of controls. The recovery rate was higher in the control group than in case group: 27.08% versus 14.63%. The death rate was higher in the case group than in the control group: 21.95% versus 6.25%. These findings demonstrate a link between malaria and HIV. The frequency of malaria episodes was higher in patients with HIV infection than patients without HIV infection and the outcome of malarial episodes was better in patients without HIV infection.

Water resources implications of integrating malaria control into the operation of an Ethiopian dam

NASA Astrophysics Data System (ADS)

Reis, Julia; Culver, Teresa B.; McCartney, Matthew; Lautze, Jonathan; Kibret, Solomon

2011-09-01

This paper investigates the water resources implications of using a method of hydrological control to reduce malaria around the Koka reservoir in central Ethiopia. This method is based on recent findings that malaria is transmitted from the shoreline of the Koka reservoir, and on a similar method that was used to control malaria some 80 yr ago in the United States. To assess the feasibility of implementing hydrological control at Koka, we considered the potential impact of the modified management regime on the benefits derived from current uses of the reservoir water (i.e., hydropower, irrigation, flood control, water supply, and downstream environmental flows). We used the HEC-ResSim model to simulate lowering the reservoir by a rate designed to disrupt larval development, which is expected to reduce the abundance of adult mosquito vectors and therefore reduce malaria transmission during the season in which transmission of the disease peaks. A comparison was made of major reservoir uses with and without the malaria control measure. In the 26-yr simulation, application of the malaria control measure increased total average annual electricity generation from 87.6 GWh × y-1 to 92.2 GWh × y-1 (i.e., a 5.3% increase) but resulted in a small decline in firm power generation (i.e., guaranteed at 99.5% reliability) from 4.16 MW to 4.15 MW (i.e., a 0.2% decrease). Application of the malaria control measure did not impact the ability of the reservoir to meet downstream irrigation demand and reduced the number of days of downstream flooding from 28 to 24 d. These results indicate that targeted use of hydrological control for malaria vector management could be undertaken without sacrificing the key benefits of reservoir operation.

Malaria among gold miners in southern Pará, Brazil: estimates of determinants and individual costs.

PubMed

Vosti, S A

1990-01-01

As malaria grows more prevalent in the Amazon frontier despite increased expenditures by disease control authorities, national and regional tropical disease control strategies are being called into question. The current crisis involving traditional control/eradication methods has broadened the search for feasible and effective malaria control strategies--a search that necessarily includes an investigation of the roles of a series of individual and community-level socioeconomic characteristics in determining malaria prevalence rates, and the proper methods of estimating these links. In addition, social scientists and policy makers alike know very little about the economic costs associated with malarial infections. In this paper, I use survey data from several Brazilian gold mining areas to (a) test the general reliability of malaria-related questionnaire response data, and suggest categorization methods to minimize the statistical influence of exaggerated responses, (b) estimate three statistical models aimed at detecting the socioeconomic determinants of individual malaria prevalence rates, and (c) calculate estimates of the average cost of a single bout of malaria. The results support the general reliability of survey response data gathered in conjunction with malaria research. Once the effects of vector exposure were controlled for, individual socioeconomic characteristics were only weakly linked to malaria prevalence rates in these very special miners' communities. Moreover, the socioeconomic and exposure links that were significant did not depend on the measure of malaria adopted. Finally, individual costs associated with malarial infections were found to be a significant portion of miners' incomes.

Lessons from malaria control to help meet the rising challenge of dengue.

PubMed

Anders, Katherine L; Hay, Simon I

2012-12-01

Achievements in malaria control could inform efforts to control the increasing global burden of dengue. Better methods for quantifying dengue endemicity-equivalent to parasite prevalence surveys and endemicity mapping used for malaria-would help target resources, monitor progress, and advocate for investment in dengue prevention. Success in controlling malaria has been attributed to widespread implementation of interventions with proven efficacy. An improved evidence base is needed for large-scale delivery of existing and novel interventions for vector control, alongside continued investment in dengue drug and vaccine development. Control of dengue is unlikely to be achieved without coordinated international financial and technical support for national programmes, which has proven effective in reducing the global burden of malaria. Copyright © 2012 Elsevier Ltd. All rights reserved.

Rationale for the Coadministration of Albendazole and Ivermectin to Humans for Malaria Parasite Transmission Control

PubMed Central

Kobylinski, Kevin C.; Alout, Haoues; Foy, Brian D.; Clements, Archie; Adisakwattana, Poom; Swierczewski, Brett E.; Richardson, Jason H.

2014-01-01

Recently there have been calls for the eradication of malaria and the elimination of soil-transmitted helminths (STHs). Malaria and STHs overlap in distribution, and STH infections are associated with increased risk for malaria. Indeed, there is evidence that suggests that STH infection may facilitate malaria transmission. Malaria and STH coinfection may exacerbate anemia, especially in pregnant women, leading to worsened child development and more adverse pregnancy outcomes than these diseases would cause on their own. Ivermectin mass drug administration (MDA) to humans for malaria parasite transmission suppression is being investigated as a potential malaria elimination tool. Adding albendazole to ivermectin MDAs would maximize effects against STHs. A proactive, integrated control platform that targets malaria and STHs would be extremely cost-effective and simultaneously reduce human suffering caused by multiple diseases. This paper outlines the benefits of adding albendazole to ivermectin MDAs for malaria parasite transmission suppression. PMID:25070998

High burden of malaria and anemia among tribal pregnant women in a chronic conflict corridor in India.

PubMed

Corrêa, Gustavo; Das, Mrinalini; Kovelamudi, Rama; Jaladi, Nagendra; Pignon, Charlotte; Vysyaraju, Kalyan; Yedla, Usha; Laxmi, Vijya; Vemula, Pavani; Gowthami, Vijaya; Sharma, Hemant; Remartinez, Daniel; Kalon, Stobdan; de Polnay, Kirrily; De Smet, Martin; Isaakidis, Petros

2017-01-01

With more than 200 million cases a year, malaria is an important global health concern, especially among pregnant women. The forested tribal areas of Andhra Pradesh, Telangana and Chhattisgarh in India are affected by malaria and by an on-going chronic conflict which seriously limits access to health care. The burden of malaria and anemia among pregnant women in these areas is unknown; moreover there are no specific recommendations for pregnant women in the Indian national malaria policy. The aim of this study is to measure the burden of malaria and anemia among pregnant women presenting in mobile clinics for antenatal care in a conflict-affected corridor in India. This is a descriptive study of routine programme data of women presenting at first visit for antenatal care in Médecins sans Frontières mobile clinics during 1 year (2015). Burden of malaria and anemia were estimated using rapid diagnostic tests (SD BIOLINE® and HemoCue® respectively). Among 575 pregnant women (median age: 26 years, interquartile range: 25-30) 29% and 22% were in their first and second pregnancies respectively. Mid-Upper Arm Circumference (MUAC) was below 230 mm in 74% of them. The prevalence of anemia was 92.4% (95% Confidence Intervals (CI): 89.9-94.3), while severe anemia was identified in 6.9% of the patients. The prevalence of malaria was 29.3% (95%CI: 25.7-33.2) with 64% caused by isolated P. falciparum , 35% by either P. falciparum or mixed malaria and 1% by either P. vivax , or P.malariae or P. ovale . Malaria test was positive in 20.8% of asymptomatic cases. Malaria was associated with severe anemia (prevalence ratio: 2.56, 95%CI: 1.40-4.66, p  < 0.01). Systematic screening for malaria and anemia should be integrated into maternal and child health services for conflict affected populations in highly endemic tribal areas. Interventions should include the use of rapid diagnostic test for all pregnant women at every visit, regardless of symptoms. Further studies should evaluate the impact of this intervention alone or in combination with intermittent malaria preventive treatment.

Long-lasting permethrin-impregnated clothing: protective efficacy against malaria in hyperendemic foci, and laundering, wearing, and weathering effects on residual bioactivity after worst-case use in the rain forests of French Guiana.

PubMed

Most, Bruno; Pommier de Santi, Vincent; Pagès, Frédéric; Mura, Marie; Uedelhoven, Waltraud M; Faulde, Michael K

2017-02-01

Personal protective measures against hematophagous vectors constitute the first line of defense against arthropod-borne diseases. However, guidelines for the standardized testing and licensing of insecticide-treated clothing are still lacking. The aim of this study was to analyze the preventive effect of long-lasting polymer-coated permethrin-impregnated clothing (PTBDU) against malaria after exposure to high-level disease transmission sites as well as the corresponding loss of permethrin and bioactivity during worst-case field use. Between August 2011 and June 2012, 25 personnel wearing PTBDUs and exposed for 9.5 person-months in hyperendemic malaria foci in the rain forest of French Guiana contracted no cases of malaria, whereas 125 persons wearing untreated uniforms only, exposed for 30.5 person-months, contracted 11 cases of malaria, indicating that PTBDU use significantly (p = 0.0139) protected against malaria infection. In the field, PTBDUs were laundered between 1 and 218 times (mean 25.2 ± 44.8). After field use, the mean remaining permethrin concentration in PTBDU fabric was 732.1 ± 321.1 min varying between 130 and 1270 mg/m 2 (mean 743.9 ± 304.2 mg/m 2 ) in blouses, and between 95 and 1290 mg/m 2 (mean 720.2 ± 336.9 mg/m 2 ) in trousers. Corresponding bioactivity, measured according to internal licensing conditions as KD 99 times against Aedes aegypti mosquitoes, varied between 27.5 and 142.5 min (mean 47.7 ± 22.1 min) for blouses, and between 25.0 and 360 min (mean 60.2 ± 66.1 min) for trousers. We strongly recommend the use of long-lasting permethrin-impregnated clothing for the prevention of mosquito-borne diseases, including chikungunya, dengue, and zika fevers, which are currently resurging globally.

History of malaria control in Tajikistan and rapid malaria appraisal in an agro-ecological setting.

PubMed

Matthys, Barbara; Sherkanov, Tohir; Karimov, Saifudin S; Khabirov, Zamonidin; Mostowlansky, Till; Utzinger, Jürg; Wyss, Kaspar

2008-10-26

Reported malaria cases in rice growing areas in western Tajikistan were at the root of a rapid appraisal of the local malaria situation in a selected agro-ecological setting where only scarce information was available. The rapid appraisal was complemented by a review of the epidemiology and control of malaria in Tajikistan and Central Asia from 1920 until today. Following a resurgence in the 1990s, malaria transmission has been reduced considerably in Tajikistan as a result of concerted efforts by the government and international agencies. The goal for 2015 is transmission interruption, with control interventions and surveillance currently concentrated in the South, where foci of Plasmodium vivax and Plasmodium falciparum persist. The rapid malaria appraisal was carried out in six communities of irrigated rice cultivation during the peak of malaria transmission (August/September 2007) in western Tajikistan. In a cross-sectional survey, blood samples were taken from 363 schoolchildren and examined for Plasmodium under a light microscope. A total of 56 farmers were interviewed about agricultural activities and malaria. Potential Anopheles breeding sites were characterized using standardized procedures. A literature review on the epidemiology and control of malaria in Tajikistan was conducted. One case of P. vivax was detected among the 363 schoolchildren examined (0.28%). The interviewees reported to protect themselves against mosquito bites and used their own concepts on fever conditions, which do not distinguish between malaria and other diseases. Three potential malaria vectors were identified, i.e. Anopheles superpictus, Anopheles pulcherrimus and Anopheles hyrcanus in 58 of the 73 breeding sites examined (79.5%). Rice paddies, natural creeks and man-made ponds were the most important Anopheles habitats. The presence of malaria vectors and parasite reservoirs, low awareness of, and protection against malaria in the face of population movements and inadequate surveillance may render local communities vulnerable to potential epidemics. To attain malaria transmission interruption in Tajikistan by 2015, there is a need for rigorous surveillance along with strengthening of primary health care facilities for effective case management, and possibly a more differentiated vector control strategy based on additional local evidence.

Factoring quality laboratory diagnosis into the malaria control agenda for sub-Saharan Africa.

PubMed

Aidoo, Michael

2013-09-01

Recent progress in malaria control in sub-Saharan Africa has been achieved primarily through provision of insecticide-treated nets, indoor residual spraying, and antimalarial drugs. Although these interventions are important, proper case identification and accurate measurement of their impact depend on quality diagnostic testing. Current availability of diagnostic testing for malaria in sub-Saharan Africa is inadequate to support disease management, prevention programs, and surveillance needs. Challenges faced include a dearth of skilled workforce, inadequate health systems infrastructure, and lack of political will. A coordinated approach to providing pre-service clinical and laboratory training together with systems that support a scale-up of laboratory services could provide means not only for effective malaria case management but also, management of non-malaria febrile illnesses, disease surveillance, and accurate control program evaluation. A synthesis of the challenges faced in ensuring quality malaria testing and how to include this information in the malaria control and elimination agenda are presented.

Using Rainfall and Temperature Data in the Evaluation of National Malaria Control Programs in Africa

PubMed Central

Thomson, Madeleine C.; Ukawuba, Israel; Hershey, Christine L.; Bennett, Adam; Ceccato, Pietro; Lyon, Bradfield; Dinku, Tufa

2017-01-01

Abstract. Since 2010, the Roll Back Malaria (RBM) Partnership, including National Malaria Control Programs, donor agencies (e.g., President's Malaria Initiative and Global Fund), and other stakeholders have been evaluating the impact of scaling up malaria control interventions on all-cause under-five mortality in several countries in sub-Saharan Africa. The evaluation framework assesses whether the deployed interventions have had an impact on malaria morbidity and mortality and requires consideration of potential nonintervention influencers of transmission, such as drought/floods or higher temperatures. Herein, we assess the likely effect of climate on the assessment of the impact malaria interventions in 10 priority countries/regions in eastern, western, and southern Africa for the President's Malaria Initiative. We used newly available quality controlled Enhanced National Climate Services rainfall and temperature products as well as global climate products to investigate likely impacts of climate on malaria evaluations and test the assumption that changing the baseline period can significantly impact on the influence of climate in the assessment of interventions. Based on current baseline periods used in national malaria impact assessments, we identify three countries/regions where current evaluations may overestimate the impact of interventions (Tanzania, Zanzibar, Uganda) and three countries where current malaria evaluations may underestimate the impact of interventions (Mali, Senegal and Ethiopia). In four countries (Rwanda, Malawi, Mozambique, and Angola) there was no strong difference in climate suitability for malaria in the pre- and post-intervention period. In part, this may be due to data quality and analysis issues. PMID:28990912

Strengthening malaria prevention and control: integrating West African militaries' malaria control efforts. The inaugural meeting of the West African Malaria Task Force, April 24-26, 2013, Accra, Ghana.

PubMed

McCollum, Jeffrey T; Hanna, Refaat; Halbach, Alaina C; Cummings, James F

2015-01-01

From April 24 to 26, 2013, the Armed Forces Health Surveillance Center and the U.S. Africa Command cosponsored the inaugural meeting of the West Africa Malaria Task Force in Accra, Ghana. The meeting's purpose was to identify common challenges, explore regional and transcontinental collaborations, and to share knowledge about best practices in the fight against malaria in West Africa. Military representatives from Benin, Burkina Faso, Ghana, Liberia, Niger, Nigeria, Senegal, and Togo participated in the Task Force; various U.S. Government agencies were also represented, including the Department of Defense, the Centers for Disease Control and Prevention, and the Agency for International Development. African nation participants presented brief overviews of their military's malaria prevention and control measures, surveillance programs, diagnostic capabilities, and treatment regimens emphasizing gaps within existing programs. Representatives from U.S. agencies discussed activities and capabilities relevant for the region, challenges and lessons learned regarding malaria, and highlighted opportunities for enhanced partnerships to counter malaria in West Africa. This article summarizes the major conclusions of the Task Force meeting, identifies relevant focus areas for future Task Force activities, and outlines opportunities for further inclusion of West African militaries to improve regional malaria surveillance and control efforts. Reprint & Copyright © 2015 Association of Military Surgeons of the U.S.

Renewed mobilization against malaria.

PubMed

1991-01-01

1 million people die in the world from malaria annually, 800,000 of whom are 5 year old children in Sub-Sahara Africa. Further it affects 270 million people. In fact, 110 million develop malaria, 90 million of whom are from Sub-Saharan Africa. Thus WHO has introduced a new world initiative for malaria control to reverse the worsening trend that began in the mid 1970s. In October 1991, 150 officials from 50 African, Asian, and Latin American countries and participants from UN cooperation and development agencies and bilateral agencies attended an interregional conference at the WHO Regional office for Africa in Brazzaville, Congo. It strove to evaluate malaria situations specific to Africa, to update the malaria control plan in Africa, and to contribute to the development of an implementable world strategy. This world strategy needs to consider the local situation and encourage participation of the government and people of affected countries. Further individuals, communities, and various sectors of the national economy including those involved in health, education, development, and agriculture need to participate in malaria control. In addition, for this strategy to work, most countries must strengthen the management and financing of health services to meet their needs. For example, local populations must share local operating costs such as those for essential drugs and mosquito control operations. Community participation must also include personal protection such as impregnated bed nets and environmental measures. Besides malaria control must be integrated into the existing health system at country, provincial, and peripheral levels. In sum, improved case management, control of malaria transmission, and prevention and control of epidemics form the basis for the new strategy.

"Alert-Audit-Act": assessment of surveillance and response strategy for malaria elimination in three low-endemic settings of Myanmar in 2016.

PubMed

Kyaw, Aye Mon Mon; Kathirvel, Soundappan; Das, Mrinalini; Thapa, Badri; Linn, Nay Yi Yi; Maung, Thae Maung; Lin, Zaw; Thi, Aung

2018-01-01

Myanmar, a malaria endemic country of Southeast Asia, adopted surveillance and response strategy similar to "1-3-7" Chinese strategy to achieve sub-national elimination in six low-endemic region/states of the country. Among these, Yangon, Bago-East, and Mon region/states have implemented this malaria surveillance and response strategy with modification in 2016. The current study was conducted to assess the case notification, investigation, classification, and response strategy (NICR) in these three states. This was a retrospective cohort study using routine program data of all patients with malaria diagnosed and reported under the National Malaria Control Programme in 2016 from the above three states. As per the program, all malaria cases need to be notified within 1 day and investigated within 3 days of diagnosis and response to control (active case detection and control) should be taken for all indigenous malaria cases within 7 days of diagnosis. A total of 959 malaria cases were diagnosed from the study area in 2016. Of these, the case NICR details were available only for 312 (32.5%) malaria cases. Of 312 cases, the case notification, investigation, and classification were carried out within 3 days of malaria diagnosis in 95.5% cases (298/312). Of 208 indigenous malaria cases (66.7%, 208/312), response to control was taken in 96.6% (201/208) within 7 days of diagnosis. The timeline at each stage of the strategy namely case notification, investigation, classification, and response to control was followed, and response action was taken in nearly all indigenous malaria cases for the available case information. Strengthening of health information and monitoring system is needed to avoid missing information. Future research on feasibility of mobile/tablet-based surveillance system and providing response to all cases including imported malaria can be further studied.

Challenges for malaria elimination in Brazil.

PubMed

Ferreira, Marcelo U; Castro, Marcia C

2016-05-20

Brazil currently contributes 42 % of all malaria cases reported in the Latin America and the Caribbean, a region where major progress towards malaria elimination has been achieved in recent years. In 2014, malaria burden in Brazil (143,910 microscopically confirmed cases and 41 malaria-related deaths) has reached its lowest levels in 35 years, Plasmodium falciparum is highly focal, and the geographic boundary of transmission has considerably shrunk. Transmission in Brazil remains entrenched in the Amazon Basin, which accounts for 99.5 % of the country's malaria burden. This paper reviews major lessons learned from past and current malaria control policies in Brazil. A comprehensive discussion of the scientific and logistic challenges that may impact malaria elimination efforts in the country is presented in light of the launching of the Plan for Elimination of Malaria in Brazil in November 2015. Challenges for malaria elimination addressed include the high prevalence of symptomless and submicroscopic infections, emerging anti-malarial drug resistance in P. falciparum and Plasmodium vivax and the lack of safe anti-relapse drugs, the largely neglected burden of malaria in pregnancy, the need for better vector control strategies where Anopheles mosquitoes present a highly variable biting behaviour, human movement, the need for effective surveillance and tools to identify foci of infection in areas with low transmission, and the effects of environmental changes and climatic variability in transmission. Control actions launched in Brazil and results to come are likely to influence control programs in other countries in the Americas.

Epidemic pox and malaria in native forest birds

USGS Publications Warehouse

Atkinson, C. T.; Dusek, R. J.; Iko, W. M.

1993-01-01

Studies by Warner in the 1950’s and van Riper in the 1970’s identified disease as a potential limiting factor in the distribution and abundance of Hawaii’s native forest birds. Mosquito-transmitted protozoan and viral infections caused by malarial parasites and pox virus were especially significant. Both organisms were introduced to the islands after the arrival of Europeans and are thought to have affected avian communities the same way that measles devastated native Hawaiian peoples.

Health, human rights, and malaria control: historical background and current challenges.

PubMed

Brentlinger, Paula E

2006-01-01

Malaria, a parasitic infection, causes hundreds of millions of disease episodes and more than a million deaths every year, nearly all of them occurring in the poorer and more vulnerable sectors of the world's developing countries. In spite of the great burden of suffering caused by malaria, the human rights implications of this disease have not been well described. This article summarizes important associations between the spread of malaria and human rights abuses (such as those associated with slavery and armed conflict) and between poverty, socio-economic inequity, and access to malaria-control measures. The author concludes that malaria control merits inclusion as a core element in global strategies to achieve progressive realization of the right to health.

Evaluation of Commercial Agrochemicals as New Tools for Malaria Vector Control.

PubMed

Hoppé, Mark; Hueter, Ottmar F; Bywater, Andy; Wege, Philip; Maienfisch, Peter

2016-10-01

Malaria is a vector-borne and life-threatening disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes. The vector control insecticide market represents a small fraction of the crop protection market and is estimated to be valued at up to $500 million at the active ingredient level. Insecticide resistance towards the current WHOPES-approved products urgently requires the development of new tools to protect communities against the transmission of malaria. The evaluation of commercial products for malaria vector control is a viable and cost effective strategy to identify new malaria vector control products. Several examples of such spin-offs from crop protection insecticides are already evidencing the success of this strategy, namely pirimiphos-methyl for indoor residual sprays and spinosad, diflubenzuron, novaluron, and pyriproxifen for mosquito larvae control, a supplementary technology for control of malaria vectors. In our study the adulticidal activities of 81 insecticides representing 23 insecticidal modes of action classes, 34 fungicides from 6 fungicidal mode of action classes and 15 herbicides from 2 herbicidal modes of action classes were tested in a newly developed screening system. WHOPES approved insecticides for malaria vector control consistently caused 80-100% mortality of adult Anopheles stephensi at application rates between 0.2 and 20 mg active ingradient (AI) litre -1 . Chlorfenapyr, fipronil, carbosulfan and endosulfan showed the expected good activity. Four new insecticides and three fungicides with promising activity against adult mosquitoes were identified, namely the insecticides acetamiprid, thiamethoxam, thiocyclam and metaflumizone and the fungicides diflumetorin, picoxystrobin, and fluazinam. Some of these compounds certainly deserve to be further evaluated for malaria vector control. This is the first report describing good activity of commercial fungicides against malaria vectors.

Host susceptibility to malaria in human and mice: compatible approaches to identify potential resistant genes.

PubMed

Hernandez-Valladares, Maria; Rihet, Pascal; Iraqi, Fuad A

2014-01-01

There is growing evidence for human genetic factors controlling the outcome of malaria infection, while molecular basis of this genetic control is still poorly understood. Case-control and family-based studies have been carried out to identify genes underlying host susceptibility to malarial infection. Parasitemia and mild malaria have been genetically linked to human chromosomes 5q31-q33 and 6p21.3, and several immune genes located within those regions have been associated with malaria-related phenotypes. Association and linkage studies of resistance to malaria are not easy to carry out in human populations, because of the difficulty in surveying a significant number of families. Murine models have proven to be an excellent genetic tool for studying host response to malaria; their use allowed mapping 14 resistance loci, eight of them controlling parasitic levels and six controlling cerebral malaria. Once quantitative trait loci or genes have been identified, the human ortholog may then be identified. Comparative mapping studies showed that a couple of human and mouse might share similar genetically controlled mechanisms of resistance. In this way, char8, which controls parasitemia, was mapped on chromosome 11; char8 corresponds to human chromosome 5q31-q33 and contains immune genes, such as Il3, Il4, Il5, Il12b, Il13, Irf1, and Csf2. Nevertheless, part of the genetic factors controlling malaria traits might differ in both hosts because of specific host-pathogen interactions. Finally, novel genetic tools including animal models were recently developed and will offer new opportunities for identifying genetic factors underlying host phenotypic response to malaria, which will help in better therapeutic strategies including vaccine and drug development.

Potential of household environmental resources and practices in eliminating residual malaria transmission: a case study of Tanzania, Burundi, Malawi and Liberia.

PubMed

Semakula, Henry M; Song, Guobao; Zhang, Shushen; Achuu, Simon P

2015-09-01

The increasing protection gaps of insecticide-treated nets and indoor-residual spraying methods against malaria have led to an emergence of residual transmission in sub-Saharan Africa and thus, supplementary strategies to control mosquitoes are urgently required. To assess household environmental resources and practices that increase or reduce malaria risk among children under-five years of age in order to identify those aspects that can be adopted to control residual transmission. Household environmental resources, practices and malaria test results were extracted from Malaria Indicators Survey datasets for Tanzania, Burundi, Malawi and Liberia with 16,747 children from 11,469 households utilised in the analysis. Logistic regressions were performed to quantify the contribution of each factor to malaria occurrence. Cattle rearing reduced malaria risk between 26%-49% while rearing goats increased the risk between 26%-32%. All piped-water systems reduced malaria risk between 30%-87% (Tanzania), 48%-95% (Burundi), 67%-77% (Malawi) and 58%-73 (Liberia). Flush toilets reduced malaria risk between 47%-96%. Protected-wells increased malaria risk between 19%-44%. Interestingly, boreholes increased malaria risk between 19%-75%. Charcoal use reduced malaria risk between 11%-49%. Vector control options for tackling mosquitoes were revealed based on their risk levels. These included cattle rearing, installation of piped-water systems and flush toilets as well as use of smokeless fuels.

Integrating child health services into malaria control services of village malaria workers in remote Cambodia: service utilization and knowledge of malaria management of caregivers.

PubMed

Hasegawa, Aya; Yasuoka, Junko; Ly, Po; Nguon, Chea; Jimba, Masamine

2013-08-23

Malaria and other communicable diseases remain major threats in developing countries. In Cambodia, village malaria workers (VMWs) have been providing malaria control services in remote villages to cope with the disease threats. In 2009, the VMW project integrated child health services into the original malaria control services. However, little has been studied about the utilization of VMWs' child health services. This study aimed to identify determinants of caregivers' VMW service utilization for childhood illness and caregivers' knowledge of malaria management. A cross-sectional study was conducted in 36 VMW villages of Kampot and Kampong Thom provinces in July-September 2012. An equal number of VMW villages with malaria control services only (M) and those with malaria control plus child health services (M+C) were selected from each province. Using structured questionnaires, 800 caregivers of children under five and 36 VMWs, one of the two VMWs who was providing VMW services in each study village were interviewed. Among the caregivers, 23% in M villages and 52% in M+C villages utilized VMW services for childhood illnesses. Determinants of caregivers' utilization of VMWs in M villages included their VMWs' length of experience (AOR = 11.80, 95% confidence interval [CI] = 4.46-31.19) and VMWs' service quality (AOR = 2.04, CI = 1.01-4.11). In M+C villages, VMWs' length of experience (AOR = 2.44, CI = 1.52-3.94) and caregivers' wealth index (AOR = 0.35, CI = 0.18-0.68) were associated with VMW service utilization. Meanwhile, better service quality of VMWs (AOR = 3.21, CI = 1.34-7.66) and caregivers' literacy (AOR = 9.91, CI = 4.66-21.05) were positively associated with caregivers' knowledge of malaria management. VMWs' service quality and length of experience are important determinants of caregivers' utilization of VMWs' child health services and their knowledge of malaria management. Caregivers are seeking VMWs' support for childhood illnesses even if they are providing only malaria control services. This underlines the importance of scaling-up VMWs' capacity by adding child health services of good quality, which will result in improving child health status in remote Cambodia.

Perceptions of malaria control and prevention in an era of climate change: a cross-sectional survey among CDC staff in China.

PubMed

Tong, Michael Xiaoliang; Hansen, Alana; Hanson-Easey, Scott; Cameron, Scott; Xiang, Jianjun; Liu, Qiyong; Liu, Xiaobo; Sun, Yehuan; Weinstein, Philip; Han, Gil-Soo; Williams, Craig; Bi, Peng

2017-03-31

Though there was the significant decrease in the incidence of malaria in central and southwest China during the 1980s and 1990s, there has been a re-emergence of malaria since 2000. A cross-sectional survey was conducted amongst the staff of eleven Centers for Disease Control and Prevention (CDC) in China to gauge their perceptions regarding the impacts of climate change on malaria transmission and its control and prevention. Descriptive analysis was performed to study CDC staff's knowledge, attitudes, perceptions and suggestions for malaria control in the face of climate change. A majority (79.8%) of CDC staff were concerned about climate change and 79.7% believed the weather was becoming warmer. Most participants (90.3%) indicated climate change had a negative effect on population health, 92.6 and 86.8% considered that increasing temperatures and precipitation would influence the transmission of vector-borne diseases including malaria. About half (50.9%) of the surveyed staff indicated malaria had re-emerged in recent years, and some outbreaks were occurring in new geographic areas. The main reasons for such re-emergence were perceived to be: mosquitoes in high-density, numerous imported cases, climate change, poor environmental conditions, internal migrant populations, and lack of health awareness. This study found most CDC staff endorsed the statement that climate change had a negative impact on infectious disease transmission. Malaria had re-emerged in some areas of China, and most of the staff believed that this can be managed. However, high densities of mosquitoes and the continuous increase in imported cases of malaria in local areas, together with environmental changes are bringing about critical challenges to malaria control in China. This study contributes to an understanding of climate change related perceptions of malaria control and prevention amongst CDC staff. It may help to formulate in-house training guidelines, community health promotion programmes and policies to improve the capacity of malaria control and prevention in the face of climate change in China.

[A history of malaria in modern Korea 1876-1945].

PubMed

Yeo, Insok

2011-06-30

Although it is not certain when malaria began to appear in Korea, malaria is believed to have been an endemic disease from ancient times. It was Dr. H. N. Allen (1858-1932) who made the first description and diagnosis of malaria in terms of Western medicine. In his first year report (1885) of Korean Government Hospital he mentioned malaria as the most prevalent disease. Very effective anti-malarial drug quinine was imported and it made great contribution in treating malaria. After Japan had annexed Korea in 1910, policies for public health system were fundamentally revised. Japan assumed control of Korean medical institutions and built high-quality Western hospitals for the health care of Japanese residents. The infectious diseases which were under special surveillance were cholera, typhoid fever, dysentery, typhus, scarlet fever, smallpox, and paratyphoid fever. Among chronic infectious diseases tuberculosis and leprosy were those under special control. Malaria, however, was not one of these specially controlled infectious diseases although it was widely spread throughout the peninsula. But serious studies on malaria were carried out by Japanese medical scientists. In particular, a Japanese parasitologist Kobayasi Harujiro(1884-1969) carried out extensive studies on human parasites, including malaria, in Korea. According to his study, most of the malaria in Korea turned out to be tertian fever. In spite of its high prevalence, malaria did not draw much attention from the colonial authorities and no serious measure was taken since tertian fever is a mild form of malaria caused by Plasmodium vivax and is not so much fatal as tropical malaria caused by P. falciparum. And tertian malaria was easily controlled by taking quinine. Although the majority of malaria in Korea was tertian fever, other types were not absent. Quartan fever was not rarely reported in 1930s. The attitude of colonial authorities toward malaria in Korea was contrasted with that in Taiwan. After Japan had set out to colonize Taiwan as a result of Sino-Japanese war, malaria in Taiwan was a big obstacle to the colonization process. Therefore, a lot of medical scientists were asked to engage the malaria research in order to handle health problems in colonized countries caused by malaria. Unlike the situation in Taiwan, malaria in Korea did not cause a serious health problem as in Taiwan. However, its risk was not negligible. In 1933 there were almost 130,000 malaria patients in Korea and 1,800 patients among them died of malaria. The Japanese Government General took measures to control malaria especially during the 1930s and the number of patients decreased. However, as Japan engaged in the World War II, the general hygienic state of the society worsened and the number of malarial patients increased. The worsened situation remains the same after Liberation (1945) and during the Korean war (1950-53).

Therapeutic efficacy of artemether-lumefantrine combination in the treatment of uncomplicated malaria among children under five years of age in three ecological zones in Ghana.

PubMed

Abuaku, Benjamin; Duah, Nancy; Quaye, Lydia; Quashie, Neils; Koram, Kwadwo

2012-11-22

In 2008, artemether - lumefantrine (AL) and dihydroartemisinin - piperaquine (DHAP) were added to artesunate - amodiaquine (AS-AQ) as first-line drugs for uncomplicated malaria in Ghana. The introduction of new drugs calls for continuous monitoring of these drugs to provide timely information on trends of their efficacy and safety to enhance timely evidence-based decision making by the National Malaria Control Programme. In this regard, the therapeutic efficacy of AL was monitored from September 2010 to April 2011 in four sentinel sites representing the three main ecological zones of the country. The study was a one-arm prospective evaluation of clinical and parasitological responses to directly observed treatment for uncomplicated malaria among children aged 6 months to 59 months using the 2009 WHO protocol for surveillance of anti-malarial drug efficacy. Children recruited into the study received weight-based 20/120 mg AL at 0, 8, 24, 36, 48, and 60 hrs. Parasitaemia levels were assessed on days 2, 3, 7, 14, 21, 28, and at any time a study child was brought to the clinic with fever. A total of 175 children were enrolled into the study: 56 in the savanna zone, 78 in the forest zone and 41 in the coastal zone. Per-protocol analysis showed that the overall PCR-corrected cure rates on day 14 and day 28 were 96.5% (95% CI: 92.1, 98.6) and 95.4% (95% CI: 90.3, 98.0), respectively, with statistically significant differences between the ecological zones. The 90.4% day-28 cure rate observed in the savannah zone (95% CI: 78.2, 96.4) was significantly the lowest compared with 100% (95% CI: 93.2, 99.9) in the forest zone and 93.8% (95% CI: 77.8, 98.9) in the coastal zone (P = 0.017). Fever and parasite clearance were slower among children enrolled in the savannah zone. Gametocytaemia after day-3 post-treatment was rare in all the zones. The study has shown that AL remains efficacious in Ghana with significant ecologic zonal differences. The savannah zone may be a potential zone for any emergence of resistant alleles as a result of the slower parasite clearance observed in the zone.

Individual-level factors associated with the risk of acquiring human Plasmodium knowlesi malaria in Malaysia: a case-control study.

PubMed

Grigg, Matthew J; Cox, Jonathan; William, Timothy; Jelip, Jenarun; Fornace, Kimberly M; Brock, Patrick M; von Seidlein, Lorenz; Barber, Bridget E; Anstey, Nicholas M; Yeo, Tsin W; Drakeley, Christopher J

2017-06-09

The emergence of human malaria due to the monkey parasite Plasmodium knowlesi threatens elimination efforts in southeast Asia. Changes in land use are thought to be driving the rise in reported P knowlesi cases, but the role of individual-level factors is unclear. To address this knowledge gap we assessed human and environmental factors associated with zoonotic knowlesi malaria risk. We did this population-based case-control study over a 2 year period in the state of Sabah in Malaysia. We enrolled cases with microscopy-positive, PCR-confirmed malaria who presented to two primary referral hospitals serving the adjacent districts of Kudat and Kota Marudu. We randomly selected three malaria-negative community controls per case, who were matched by village within 2 weeks of case detection. We obtained questionnaire data on demographics, behaviour, and residential malaria risk factors, and we also assessed glucose-6-phosphate dehydrogenase (G6PD) enzyme activity. We used conditional logistic regression models to evaluate exposure risk between P knowlesi cases and controls, and between P knowlesi and human-only Plasmodium spp malaria cases. From Dec 5, 2012, to Jan 30, 2015, we screened 414 patients and subsequently enrolled 229 cases with P knowlesi malaria mono-infection and 91 cases with other Plasmodium spp infection. We enrolled 953 matched controls, including 683 matched to P knowlesi cases and 270 matched to non- P knowlesi cases. Age 15 years or older (adjusted odds ratio [aOR] 4·16, 95% CI 2·09-8·29, p<0·0001), male gender (4·20, 2·54-6·97, p<0·0001), plantation work (3·50, CI, 1·34-9·15, p=0·011), sleeping outside (3·61, 1·48-8·85, p=0·0049), travel (2·48, 1·45-4·23, p=0·0010), being aware of the presence of monkeys in the past 4 weeks (3·35, 1·91-5·88, p<0·0001), and having open eaves or gaps in walls (2·18, 1·33-3·59, p=0·0021) were independently associated with increased risk of symptomatic P knowlesi infection. Farming occupation (aOR 1·89, 95% CI 1·07-3·35, p=0·028), clearing vegetation (1·89, 1·11-3·22, p=0·020), and having long grass around the house (2·08, 1·25-3·46, p=0·0048) increased risk for P knowlesi infection but not other Plasmodium spp infection. G6PD deficiency seemed to be protective against P knowlesi (aOR 0·20, 95% CI 0·04-0·96, p=0·045), as did residual insecticide spraying of household walls (0·52, 0·31-0·87, p=0·014), with the presence of young sparse forest (0·35, 0·20-0·63, p=00040) and rice paddy around the house (0·16, 0·03-0·78, 0·023) also associated with decreased risk. Adult men working in agricultural areas were at highest risk of knowlesi malaria, although peri-domestic transmission also occurrs. Human behavioural factors associated with P knowlesi transmission could be targeted in future public health interventions. United Kingdom Medical Research Council, Natural Environment Research Council, Economic and Social Research Council, and Biotechnology and Biosciences Research Council.

Malaria rapid diagnostic tests.

PubMed

Wilson, Michael L

2012-06-01

Global efforts to control malaria are more complex than those for other infectious diseases, in part because of vector transmission, the complex clinical presentation of Plasmodium infections, >1 Plasmodium species causing infection, geographic distribution of vectors and infection, and drug resistance. The World Health Organization approach to global malaria control focuses on 2 components: vector control and diagnosis and treatment of clinical malaria. Although microscopy performed on peripheral blood smears remains the most widely used diagnostic test and the standard against which other tests are measured, rapid expansion of diagnostic testing worldwide will require use of other diagnostic approaches. This review will focus on the malaria rapid diagnostic test (MRDT) for detecting malaria parasitemia, both in terms of performance characteristics of MRDTs and how they are used under field conditions. The emphasis will be on the performance and use of MRDTs in regions of endemicity, particularly sub-Saharan Africa, where most malaria-related deaths occur.

Factors Influencing Prevention and Control of Malaria among Pregnant Women Resident in Urban Slums, Southern Ghana.

PubMed

Dako-Gyeke, Mavis; Kofie, Humphrey M

2015-03-01

Throughout Africa and particularly in Ghana, there are concerns about malaria infection during pregnancy. This study aimed to investigate factors that influence malaria prevention and control practices among pregnant women residing in Chorkor and Korle-Gonno in Accra, Ghana. One hundred and twenty pregnant women between ages 18-49 were randomly recruited during antenatal sessions at a maternity facility in Accra, as participants for the study. An interviewer-administered questionnaire was used to collect data, which were analysed using SPSS version16.0. It was found that in Chorkor and Korle-Gonno, 57.4% and 42.6% participants respectively reported having been infected with malaria during their current pregnancy. There was no significant relationship between religious beliefs of participants and their malaria prevention and control practices (X2 = 0.28, P = .53). However, there was a significant relationship between malaria prevention and control practices of participants and their income earning (X2 = 53.94, P = .00) and employment (X2 = 61.76, P = .00) statuses. With the exception of ethnicity (X2 = 35.62, P =.22), other socio-cultural conditions had a significant relationship with malaria prevention and control practices of the participants. The findings suggest the need to consider and integrate factors, such as poverty and poor living conditions in malaria prevention and control strategies.

The Biological Control of the Malaria Vector

PubMed Central

Kamareddine, Layla

2012-01-01

The call for malaria control, over the last century, marked a new epoch in the history of this disease. Many control strategies targeting either the Plasmodium parasite or the Anopheles vector were shown to be effective. Yet, the emergence of drug resistant parasites and insecticide resistant mosquito strains, along with numerous health, environmental, and ecological side effects of many chemical agents, highlighted the need to develop alternative tools that either complement or substitute conventional malaria control approaches. The use of biological means is considered a fundamental part of the recently launched malaria eradication program and has so far shown promising results, although this approach is still in its infancy. This review presents an overview of the most promising biological control tools for malaria eradication, namely fungi, bacteria, larvivorous fish, parasites, viruses and nematodes. PMID:23105979

Rapid immunochromatographic diagnosis and Rolling Back Malaria--experiences from an African control program.

PubMed

Durrheim, D N; Govere, J; la Grange, J J; Mabuza, A

2001-01-01

Malaria is a re-emerging disease in much of Africa. In response, the World Health Organization launched the Roll Back Malaria (RBM) initiative. One of six key principles adopted is the early detection of malaria cases. However, the importance of definitive diagnosis and potential value of field deployment of rapid malaria tests in RBM has been largely ignored. The Lowveld Region of Mpumalanga Province, South Africa, is home to a predominantly non-immune population, of approximately 850000 inhabitants, who are at risk of seasonal Plasmodium falciparum malaria. Malaria treatment in this area is usually only initiated on detection of malaria parasites in the peripheral bloodstream, as many other rickettsial and viral febrile illness mimic malaria. The malaria control programme traditionally relied on light microscopy of Giemsa-stained thick blood films for malaria diagnosis. This review summarizes operational research findings that led to the introduction of rapid malaria card tests for primary diagnosis of malaria throughout the Mpumalanga malaria area. Subsequent operational research and extensive experience over a four-year period since introducing the ICT Malaria Pf test appears to confirm the local appropriateness of this diagnostic modality. A laboratory is not required and clinic staff are empowered to make a prompt definitive diagnosis, limiting delays in initiating correct therapy. The simple, accurate and rapid non-microscopic means now available for diagnosing malaria could play an important role in Rolling Back Malaria in selected areas.

Current management and prevention of malaria in pregnancy: a review.

PubMed

Agboghoroma, C O

2014-01-01

Pregnant women suffer more frequent and severe malaria than non-pregnant women. Malaria in pregnancy contributes to the high maternal and perinatal morbidity and mortality in Africa. To review the burden and highlight the current management and prevention strategies for control of malaria in pregnancy in Africa. Papers for this review were identified by searches of PubMed and Google, and references from relevant articles. Search terms were "malaria", "malaria in pregnancy", "Malaria during pregnancy" and "antimalarial drug". Only papers published in English between 1983 and 2013 were included. In malarial endemic areas, acquired partial malarial immunity is not effective during pregnancy. Pregnant women are prone to frequent malaria infections which may be severe or asymptomatic but associated with placental parasitization. Malaria contributes 2-15% to maternal anaemia, 13-70% to intrauterine growth restriction, 8-14% to low birth weight, 8-36% to prematurity, 3-8% to infant deaths and 2.9-17.6% to maternal mortality. The control of malaria in pregnancy is currently predicated on three main strategies: 1) Prompt and effective case management of malaria; 2).Use of Insecticide-treated nets; and 3).Intermittent preventive treatment in pregnancy with sulfadoxine-pyrimethamine. Artemisinin-based combined therapy is the recommended treatment for uncomplicated malaria in the second and third trimesters of pregnancy, while quinine is used in the first trimester and for severe cases of malaria at any gestational age. The control of malaria during pregnancy should be an integral part of efforts to reduce maternal and perinatal morbidity and mortality in Africa.

Age-Specific Malaria Mortality Rates in the KEMRI/CDC Health and Demographic Surveillance System in Western Kenya, 2003–2010

PubMed Central

Desai, Meghna; Buff, Ann M.; Khagayi, Sammy; Byass, Peter; Amek, Nyaguara; van Eijk, Annemieke; Slutsker, Laurence; Vulule, John; Odhiambo, Frank O.; Phillips-Howard, Penelope A.; Lindblade, Kimberly A.; Laserson, Kayla F.; Hamel, Mary J.

2014-01-01

Recent global malaria burden modeling efforts have produced significantly different estimates, particularly in adult malaria mortality. To measure malaria control progress, accurate malaria burden estimates across age groups are necessary. We determined age-specific malaria mortality rates in western Kenya to compare with recent global estimates. We collected data from 148,000 persons in a health and demographic surveillance system from 2003–2010. Standardized verbal autopsies were conducted for all deaths; probable cause of death was assigned using the InterVA-4 model. Annual malaria mortality rates per 1,000 person-years were generated by age group. Trends were analyzed using Poisson regression. From 2003–2010, in children <5 years the malaria mortality rate decreased from 13.2 to 3.7 per 1,000 person-years; the declines were greatest in the first three years of life. In children 5–14 years, the malaria mortality rate remained stable at 0.5 per 1,000 person-years. In persons ≥15 years, the malaria mortality rate decreased from 1.5 to 0.4 per 1,000 person-years. The malaria mortality rates in young children and persons aged ≥15 years decreased dramatically from 2003–2010 in western Kenya, but rates in older children have not declined. Sharp declines in some age groups likely reflect the national scale up of malaria control interventions and rapid expansion of HIV prevention services. These data highlight the importance of age-specific malaria mortality ascertainment and support current strategies to include all age groups in malaria control interventions. PMID:25180495

[Control of malaria transmission in a gold-mining area in Amapá State, Brazil, with participation by private enterprise].

PubMed

Couto AA; Calvosa, V S; Lacerda, R; Castro, F; Santa Rosa, E; Nascimento, J M

2001-01-01

This paper reports on the epidemiological characterization of malaria following implementation of a program to control the endemic in a gold-mining area in northern Amapá State. The study focuses on total malaria cases in Amapá and the impact of the disease on the population, as represented by the Mineração Novo Astro S/A company and its employees as well as the community of Vila de Lourenço in the municipality of Calçoene, and adjacent gold miners. The effect of control measures in the program area is indicated by a significant reduction in malaria incidence and malaria-related morbidity and mortality. The importance of participation by private enterprise is emphasized, particularly in large projects for the control of endemic diseases (notably malaria) in the Amazon Region.

Application of GIS to predict malaria hotspots based on Anopheles arabiensis habitat suitability in Southern Africa

NASA Astrophysics Data System (ADS)

Gwitira, Isaiah; Murwira, Amon; Zengeya, Fadzai M.; Shekede, Munyaradzi Davis

2018-02-01

Malaria remains a major public health problem and a principal cause of morbidity and mortality in most developing countries. Although malaria still presents health problems, significant successes have been recorded in reducing deaths resulting from the disease. As malaria transmission continues to decline, control interventions will increasingly depend on the ability to define high-risk areas known as malaria hotspots. Therefore, there is urgent need to use geospatial tools such as geographic information system to detect spatial patterns of malaria and delineate disease hot spots for better planning and management. Thus, accurate mapping and prediction of seasonality of malaria hotspots is an important step towards developing strategies for effective malaria control. In this study, we modelled seasonal malaria hotspots as a function of habitat suitability of Anopheles arabiensis (A. Arabiensis) as a first step towards predicting likely seasonal malaria hotspots that could provide guidance in targeted malaria control. We used Geographical information system (GIS) and spatial statistic methods to identify seasonal hotspots of malaria cases at the country level. In order to achieve this, we first determined the spatial distribution of seasonal malaria hotspots using the Getis Ord Gi* statistic based on confirmed positive malaria cases recorded at health facilities in Zimbabwe over four years (1996-1999). We then used MAXENT technique to model habitat suitability of A. arabiensis from presence data collected from 1990 to 2002 based on bioclimatic variables and altitude. Finally, we used autologistic regression to test the extent to which malaria hotspots can be predicted using A. arabiensis habitat suitability. Our results show that A. arabiensis habitat suitability consistently and significantly (p < 0.05) predicts malaria hotspots from 1996 to 1999. Overall, our results show that malaria hotspots can be predicted using A. arabiensis habitat suitability, suggesting the possibility of developing models for malaria early warning based on vector habitat suitability.

Malaria control: achievements, problems and strategies.

PubMed

Nájera, J A

2001-06-01

Even if history has not always been the Magistra vitae, Cicero expected it to be, it should provide, as Baas said, a mirror in which to observe and compare the past and present in order to draw therefrom well-grounded conclusions for the future. Based on this belief, this paper aims to provide an overview of the foundations and development of malaria control policies during the XX century. It presents an analysis of the conflicting tendencies which shaped the development of these policies and which appear to have oscillated between calls for frontal attack in an all-out campaign and calls for sustainable gains, even if slow. It discusses the various approaches to the control of malaria, their achievements and their limitations, not only to serve as a background to understand better the foundations of current policies, but also to prevent that simplistic generalisations may again lead to exaggerated expectations and disillusion. The first part of the paper is devoted to the development of malaria control during the first half of the century, characterised by the ups and downs in the reliance on mosquito control as the control measure applicable everywhere. The proliferation of "man-made-malaria", which accompanied the push for economic development in most of the endemic countries, spurred the need for control interventions and, while great successes were obtained in many specific projects, the general campaigns proposed by the enthusiasts of vector control faced increasing difficulties in their practical implementation in the field. Important events, which may be considered representative of this period are, on the campaign approach, the success of Gorgas in the Panama Canal, but also the failure of the Mian Mir project in India; while on the developmental approach, the Italian and Dutch schools of malariology, the Tennessee Valley and the development of malaria sanitation, included the so called species sanitation. The projection of these developments to a global scale was steered by the Malaria Commission of the League of Nations and greatly supported by the Rockefeller Foundation. Perhaps the most important contribution of this period was the development of malaria epidemiology, including the study of the genesis of epidemics and their possible forecasting and prevention. Although the great effectiveness of DDT was perhaps the main determinant for proposing the global eradication of the disease in the 1950s, it was the confidence in the epidemiological knowledge and the prestige of malariology, which gave credibility to the proposal at the political level. The second part deals with the global malaria eradication campaign of the 1950s and 1960s. It recognises the enormous impact of the eradication effort in the consolidation of the control successes of the first half of the century, as well as its influence in the development of planning of health programmes. Nevertheless, it also stresses the negative influence that the failure to achieve its utopian expectations had on the general disappointment and slow progress of malaria control, which characterised the last third of the century. The paper then analyses the evolution of malaria control funding, which often appears out of tune with political statements. The fourth part is devoted to the search for realistic approaches to malaria control, leading to the adoption of the global malaria control strategy in Amsterdam in 1992, and the challenge, at the end of the century, to rally forces commensurate with the magnitude of the problem, while aiming at realistic objectives. After discussing the conflicting views on the relations between malaria and socio-economic development and the desirable integration of malaria control into sustainable development, the paper ends with some considerations on the perspectives of malaria control, as seen by the author in early 1998, just before the launching of the current Roll Back Malaria initiative by WHO.

Radar Monitoring of Wetlands for Malaria Control

NASA Technical Reports Server (NTRS)

Pope, Kevin O.

1997-01-01

Malaria is perhaps the most serious human disease problem. It inflicts millions worldwide and is on the rise in many countries where it was once under control. This rise is in part due to the high costs, both economic and environmental, of current control programs. The search for more cost-effective means to combat malaria has focussed attention on new technologies, one of which is remote sensing. Remote sensing has become an important tool in the effort to control a variety of diseases worldwide and malaria is perhaps one of the most promising. This study is part of the malaria control effort in the Central American country of Belize, which has experienced a resurgence of malaria in the last two decades. The proposed project is a feasibility study of the use of Radarsat (and other similar radar systems) to monitor seasonal changes in the breeding sites of the anopheline mosquito, which is responsible for malaria transmission. We propose that spatial and temporal changes in anopheline mosquito production can be predicted by sensing where and when their breeding sites are flooded. Timely knowledge of anopheline mosquito production is a key factor in control efforts. Such knowledge can be used by local control agencies to direct their limited resources to selected areas and time periods when the human population is at greatest risk. Radar is a key sensor in this application because frequent cloud cover during the peak periods of malaria transmission precludes the use of optical sensors.

Cross-border movement, economic development and malaria elimination in the Kingdom of Saudi Arabia.

PubMed

Al Zahrani, Mohammed H; Omar, Abdiasiis I; Abdoon, Abdelmohsin M O; Ibrahim, Ali Adam; Alhogail, Abdullah; Elmubarak, Mohamed; Elamin, Yousif Eldirdiry; AlHelal, Mohammed A; Alshahrani, Ali M; Abdelgader, Tarig M; Saeed, Ibrahim; El Gamri, Tageddin B; Alattas, Mohammed S; Dahlan, Abdu A; Assiri, Abdullah M; Maina, Joseph; Li, Xiao Hong; Snow, Robert W

2018-06-26

Malaria at international borders presents particular challenges with regards to elimination. International borders share common malaria ecologies, yet neighboring countries are often at different stages of the control-to-elimination pathway. Herein, we present a case study on malaria, and its control, at the border between Saudi Arabia and Yemen. Malaria program activity reports, case data, and ancillary information have been assembled from national health information systems, archives, and other related sources. Information was analyzed as a semi-quantitative time series, between 2000 and 2017, to provide a plausibility framework to understand the possible contributions of factors related to control activities, conflict, economic development, migration, and climate. The malaria recession in the Yemeni border regions of Saudi Arabia is a likely consequence of multiple, coincidental factors, including scaled elimination activities, cross-border vector control, periods of low rainfall, and economic development. The temporal alignment of many of these factors suggests that economic development may have changed the receptivity to the extent that it mitigated against surges in vulnerability posed by imported malaria from its endemic neighbor Yemen. In many border areas of the world, malaria is likely to be sustained through a complex congruence of factors, including poverty, conflict, and migration.

Eliminating malaria in Malaysia: the role of partnerships between the public and commercial sectors in Sabah

PubMed Central

2014-01-01

Background Countries in the Asia Pacific region have made great progress in the fight against malaria; several are rapidly approaching elimination. However, malaria control programmes operating in elimination settings face substantial challenges, particularly around mobile migrant populations, access to remote areas and the diversity of vectors with varying biting and breeding behaviours. These challenges can be addressed through subnational collaborations with commercial partners, such as mining or plantation companies, that can conduct or support malaria control activities to cover employees. Such partnerships can be a useful tool for accessing high-risk populations and supporting malaria elimination goals. Methods This observational qualitative case study employed semi-structured key informant interviews to describe partnerships between the Malaysian Malaria Control Programme (MCP), and private palm oil, rubber and acacia plantations in the state of Sabah. Semi-structured interview guides were used to examine resource commitments, incentives, challenges, and successes of the collaborations. Results Interviews with workers from private plantations and the state of Sabah MCP indicated that partnerships with the commercial sector had contributed to decreases in incidence at plantation sites since 1991. Several plantations contribute financial and human resources toward malaria control efforts and all plantations frequently communicate with the MCP to help monitor the malaria situation on-site. Management of partnerships between private corporations and government entities can be challenging, as prioritization of malaria control may change with annual profits or arrival of new management. Conclusions Partnering with the commercial sector has been an essential operational strategy to support malaria elimination in Sabah. The successes of these partnerships rely on a common understanding that elimination will be a mutually beneficial outcome for employers and the general public. Best practices included consistent communication, developing government-staffed subsector offices for malaria control on-site, engaging commercial plantations to provide financial and human resources for malaria control activities, and the development of new worker screening programmes. The successes and challenges associated with partnerships between the public and commercial sector can serve as an example for other malaria-eliminating countries with large plantation sectors, and may also be applied to other sectors that employ migrant workers or have commercial enterprises in hard to reach areas. PMID:24443824

Efficacy of Artesunate/Amodiaquine in the Treatment of Uncomplicated Malaria among Children in Ghana.

PubMed

Abuaku, Benjamin K; Mensah, Benedicta A; Ofori, Michael F; Myers-Hansen, James; Derkyi-Kwarteng, Abigail N; Essilfie, Felicia; Dokurugu, Moses; Amoakoh, Emmanuel; Koram, Kwadwo A; Ghansah, Anita

2017-09-01

The declining efficacy of chloroquine in the early 2000s in Ghana led to its replacement with artesunate/amodiaquine (AS/AQ) combination as first-line drug for treating uncomplicated malaria in 2005. Since then efficacy studies have been ongoing in the country to provide continuous data on the efficacy of AS/AQ and other alternative antimalarials (artemether/lumefantrine and dihyroartemisinin/piperaquine combinations) introduced in 2008. In vivo AS/AQ efficacy studies were conducted between June and October 2014 among children aged 6 months to 14 years, in two sentinel sites representing the forest and coastal zones of the country. The 2009 World Health Organization protocol for monitoring antimalarial drug efficacy was used in these studies. The studies showed an overall cumulative polymerase chain reaction-corrected day 28 cure rate of 97.2% (95% confidence interval [CI]: 93.6-99.1): 97.7% (95% CI: 92.0-99.7) within the forest zone and 96.7% (95% CI: 90.7-99.3) within the coastal zone ( P = 0.686). Prevalence of fever declined from 100% to < 4% after first day of treatment in both ecological zones. All children in the coastal zone had cleared parasites by day 2. Three children (3.2%) in the forest zone were parasitemic on day 2, whereas one child was parasitemic on day 3. Gametocytemia was absent in both zones after day 14, and mean hemoglobin concentration significantly increased from 10.3 g/dL (95% CI: 10.1-10.5) on day 0 to 11.8 g/dL (95% CI: 11.6-12.0) on day 28. We conclude that AS/AQ combination remains efficacious in the treatment of uncomplicated malaria in Ghana.

[Analysis on the performance evaluation of the Global Fund Malaria Programme in China from 2003 to 2013].

PubMed

Zhang, Q F; Wang, R B; Zheng, B; Xia, Z G; Zhou, S S

2017-05-06

Objective: To analyze the performance of the 5 Global Fund Malaria Programmes in China from 2003 to 2013. Methods: All of the proposals, summaries, progress reports, survey reports, Monitoring& Evaluation reports, and performance rating reports of the 5 Global Fund Malaria Programmes in China and the epidemic data of program areas were collected for statistical analysis from 2012 to 2014. Symposiums were held with relevant experts from national and provincial Centers for Disease Control and Prevention, program managers and staffs from national and provincial Global Fund Malaria Programme offices. The completion of the relevant programme indicators (including the general grant information such as program areas, beneficiaries and funding; the implementation of malaria control measures; the performance of malaria control measures; the malaria incidence in the program areas; the prevalence of malaria parasites; and program management and performance evaluation) were analyzed, and the results: of the symposiums were summarized. Results The implementation period of the 5 Global Fund Malaria Programs were as follows: Round 1 from 2003 to 2008, Round 5 from 2006 to 2010, Round 6 from 2007 to 2012, Round 10 from 2012 to 2013, and National Strategy Application (NSA) from 2010 to 2012. Under the support of all the Global Fund Malaria Programs, a total of 11 936 726 fever cases received microscopic tests, 1 485 915 confirmed and suspected malaria cases were treated, 1 579 773 Long Lasting Insecticide-treated Nets were distributed, 3 414 633 regular nets were treated by insecticide, 40 298 284 primary and middle school students received health education on malaria control. Compared with the baseline value, the completion rates of each indicator increased after the implementation of the programs. The growth value ranged from 12.83% to 83.11%, among which the biggest growth was the value of the indicator'Percentage of households with at least one LLIN/ITN in target areas', and it increased from 9.2% (baseline value of 2006) to 92.31% (value of 2012). The malaria incidence in program areas has dropped significantly year by year, the annual reported malaria incidence in Yunnan and Hainan provinces decreased from 1 950/100 000, 3 850/100 000 in 2002 to 3.31/100 000, 0.15/100 000 in 2012, the P. falciparum malaria incidence in target counties in Hainan province decreased from 90.6/100 000 in 2002 to 0/100 000 in 2012. As from the implementation of NSA grant in 2010 to 2012, the annual reported malaria incidence in 92% of the 75 Type 1 counties was less than 1 per 10 000, 60.00% of Type 1 counties and 98.69% of the 687 Type 2 counties reported zero locally transmitted malaria cases. The Global Fund Secretariat had conducted a total of 37 performance evaluations, of which 9 have been rated as A1, 4 rated as A2, 19 rated as B1 and 5 rated as B1. Conclusions: The Global Fund Malaria Program in China has been closely integrated with the goal and task of National Malaria Control Program, reducing malaria burden in target areas, and pushing Chinese malaria control efforts to move from control to elimination.

Using an intervention mapping approach for planning, implementing and assessing a community-led project towards malaria elimination in the Eastern Province of Rwanda.

PubMed

Ingabire, Chantal Marie; Hakizimana, Emmanuel; Kateera, Fredrick; Rulisa, Alexis; Van Den Borne, Bart; Nieuwold, Ingmar; Muvunyi, Claude; Koenraadt, Constantianus J M; Van Vugt, Michele; Mutesa, Leon; Alaii, Jane

2016-12-16

Active community participation in malaria control is key to achieving malaria pre-elimination in Rwanda. This paper describes development, implementation and evaluation of a community-based malaria elimination project in Ruhuha sector, Bugesera district, Eastern province of Rwanda. Guided by an intervention mapping approach, a needs assessment was conducted using household and entomological surveys and focus group interviews. Data related to behavioural, epidemiological, entomological and economical aspects were collected. Desired behavioural and environmental outcomes were identified concurrently with behavioural and environmental determinants. Theoretical methods and their practical applications were enumerated to guide programme development and implementation. An operational plan including the scope and sequence as well as programme materials was developed. Two project components were subsequently implemented following community trainings: (1) community malaria action teams (CMATs) were initiated in mid-2014 as platforms to deliver malaria preventive messages at village level, and (2) a mosquito larval source control programme using biological substances was deployed for a duration of 6 months, implemented from January to July 2015. Process and outcome evaluation has been conducted for both programme components to inform future scale up. The project highlighted malaria patterns in the area and underpinned behavioural and environmental factors contributing to malaria transmission. Active involvement of the community in collaboration with CMATs contributed to health literacy, particularly increasing ability to make knowledgeable decisions in regards to malaria prevention and control. A follow up survey conducted six months following the establishment of CMATs reported a reduction of presumed malaria cases at the end of 2014. The changes were related to an increase in the acceptance and use of available preventive measures, such as indoor residual spraying and increase in community-based health insurance membership, also considered as a predictor of prompt and adequate care. The innovative larval source control intervention contributed to reduction in mosquito density and nuisance bites, increased knowledge and skills for malaria control as well as programme ownership. This community-based programme demonstrated the feasibility and effectiveness of active community participation in malaria control activities, which largely contributed to community empowerment and reduction of presumed malaria in the area. Further studies should explore how gains may be sustained to achieve the goal of malaria pre-elimination.

Vector control for malaria and other mosquito-borne diseases. Report of a WHO study group.

PubMed

1995-01-01

Since the Ministerial Conference on Malaria in 1992, which acknowledged the urgent need for worldwide commitment to malaria control, efforts have been directed to implementation of a Global Malaria Control Strategy. Vector control, an essential component of malaria control, has become less effective in recent years, partly as a result of poor use of alternative control tools, inappropriate use of insecticides, lack of an epidemiological basis for interventions, inadequate resources and infrastructure, and weak management. Changing environmental conditions, the behavioural characteristics of certain vectors, and resistance to insecticides have added to the difficulties. This report of a WHO Study Group provides guidelines for the planning, implementation and evaluation of cost-effective and sustainable vector control in the context of the Global Malaria Control Strategy. It reviews the available methods - indoor residual spraying, personal protection, larval control and environmental management - stressing the need for selective and flexible use of interventions according to local conditions. Requirements for data collection and the appropriate use of entomological parameters and techniques are discussed and priorities identified for the development of local capacity for vector control and for operational research. Emphasis is placed both on the monitoring and evaluation of vector control to ensure cost-effectiveness and on the development of strong managerial structures, which can support community participation and intersectoral collaboration and accommodate the control of other vector-borne diseases. The report concludes with recommendations aimed at promoting the targeted and efficient use of vector control in preventing and controlling malaria, thereby reducing the threat to health and socioeconomic development in many tropical countries.

Preventing malaria in the Peruvian Amazon: a qualitative study in Iquitos, Peru.

PubMed

Newell, Ian; Wiskin, Connie; Anthoney, James; Meza, Graciela; de Wildt, Gilles

2018-01-16

In Peru, despite decades of concerted control efforts, malaria remains a significant public health burden. Peru has recently exhibited a dramatic rise in malaria incidence, impeding South America's progress towards malaria elimination. The Amazon basin, in particular the Loreto region of Peru, has been identified as a target for the implementation of intensified control strategies, aiming for elimination. No research has addressed why vector control strategies in Loreto have had limited impact in the past, despite vector control elsewhere being highly effective in reducing malaria transmission. This study employed qualitative methods to explore factors limiting the success of vector control strategies in the region. Twenty semi-structured interviews were conducted among adults attending a primary care centre in Iquitos, Peru, together with 3 interviews with key informants (health care professionals). The interviews focussed on how local knowledge, together with social and cultural attitudes, determined the use of vector control methods. Five themes emerged. (a) Participants believed malaria to be embedded within their culture, and commonly blamed this for a lack of regard for prevention. (b) They perceived a shift in mosquito biting times to early evening, rendering night-time use of bed nets less effective. (c) Poor preventive practices were compounded by a consensus that malaria prevention was the government's responsibility, and that this reduced motivation for personal prevention. (d) Participants confused the purpose of space-spraying. (e) Participants' responses also exposed persisting misconceptions, mainly concerning the cause of malaria and best practices for its prevention. To eliminate malaria from the Americas, region-specific strategies need to be developed that take into account the local social and cultural contexts. In Loreto, further research is needed to explore the potential shift in biting behaviour of Anopheles darlingi, and how this interacts with the population's social behaviours and current use of preventive measures. Attitudes concerning personal responsibility for malaria prevention and long-standing misconceptions as to the cause of malaria and best preventive practices also need to be addressed.

[Challenges of the medical entomology for the surveillance in public health in Colombia: reflections on the state of malaria].

PubMed

Brochero, Helena; Quiñones, Martha L

2008-03-01

The relevance of the medical entomology was considered with respect to current framework of malaria control programs in Colombia. A responsibility is indicated for balancing control efforts along with providing information on the malaria vectors. This knowledge must be acquired in order to focus the related activities that are required. The malaria control program must be based on results of local entomological surveillance, and the data must be in a form to give practical answers to questions regarding the control program. Difficulties in undertaking the required studies are described, particularly regarding the taxonomic identification of Colombian Anopheles in Colombia and which of these can be incriminated as malaria vectors.

How effective is integrated vector management against malaria and lymphatic filariasis where the diseases are transmitted by the same vector?

PubMed

Stone, Christopher M; Lindsay, Steve W; Chitnis, Nakul

2014-12-01

The opportunity to integrate vector management across multiple vector-borne diseases is particularly plausible for malaria and lymphatic filariasis (LF) control where both diseases are transmitted by the same vector. To date most examples of integrated control targeting these diseases have been unanticipated consequences of malaria vector control, rather than planned strategies that aim to maximize the efficacy and take the complex ecological and biological interactions between the two diseases into account. We developed a general model of malaria and LF transmission and derived expressions for the basic reproductive number (R0) for each disease. Transmission of both diseases was most sensitive to vector mortality and biting rate. Simulating different levels of coverage of long lasting-insecticidal nets (LLINs) and larval control confirms the effectiveness of these interventions for the control of both diseases. When LF was maintained near the critical density of mosquitoes, minor levels of vector control (8% coverage of LLINs or treatment of 20% of larval sites) were sufficient to eliminate the disease. Malaria had a far greater R0 and required a 90% population coverage of LLINs in order to eliminate it. When the mosquito density was doubled, 36% and 58% coverage of LLINs and larval control, respectively, were required for LF elimination; and malaria elimination was possible with a combined coverage of 78% of LLINs and larval control. Despite the low level of vector control required to eliminate LF, simulations suggest that prevalence of LF will decrease at a slower rate than malaria, even at high levels of coverage. If representative of field situations, integrated management should take into account not only how malaria control can facilitate filariasis elimination, but strike a balance between the high levels of coverage of (multiple) interventions required for malaria with the long duration predicted to be required for filariasis elimination.

Knowledge of human social and behavioral factors essential for the success of community malaria control intervention programs: The case of Lomahasha in Swaziland.

PubMed

Dlamini, Sabelo V; Liao, Chien-Wei; Dlamini, Zandile H; Siphepho, Jameson S; Cheng, Po-Ching; Chuang, Ting-Wu; Fan, Chia-Kwung

2017-04-01

Although malaria control programs have made rapid progress recently, they neglect important social and behavioral factors associated with the disease. Social, political, and cultural factors are involved in malaria control, and individuals in a community may be comfortable in behaving in ways that, to an outsider, may seem contrary to commonly held perceptions. Malaria control efforts can no longer afford to overlook the multidimensional human contexts that create and support varying notions of malaria and its prevention, treatment, and control. This study aimed to assess the knowledge and perceptions of malaria issues in the community, and to identify practices that support or hinder the progress of malaria control programs. A triangulation study involving individual interviews, focus group discussions, and observatory analysis between 2003 and 2010 at Lomahasha, a malarious community on the eastern border of Swaziland and Mozambique, was conducted. Results indicated that a high knowledge level and good perception of the disease were observed in the age group of < 40 years, contrary to those in higher age groups, among the Lomahasha community members. However, behavior of certain community groups includes practices that are not supportive of the national control program's aspirations, such as delay in seeking medical attention, staying outdoors until late, maintaining stagnant water in roadside excavations, and seeking medical assistance from wrong sources. Malpractices are more commonly observed among men, boys, and those who drink alcohol. This study suggests a thorough community diagnosis before all intervention programs for malaria control are instituted. Copyright © 2015. Published by Elsevier B.V.

New treatment policy of malaria as a part of malaria control program in Indonesia.

PubMed

Kusriastuti, Rita; Surya, Asik

2012-07-01

Malaria control program is one of the oldest program in the Ministry of Health (MoH) Republic of Indonesia. Started with effort to eradicate malaria in 1959 through Malaria Eradication Command well known as KOPEM (Komando Pembasmian Malaria) then it evolves to Malaria Control Program, Roll Back Malaria Program, and the current Malaria Elimination Program. In terms of diagnostic and treatment, the policy has formulated by strictly follow evidence-based principles as well as technical guided from World Health Organization (WHO). In 2004, based on numerous researches conducted in Indonesia the use of chloroquine was stopped and artemisinin-based combination therapy (ACT) was then initiated. For severe cases the use of intravenous (iv) Artesunate for cases treated in hospitals and intramuscular (im) Arthemeter for cases treated in the primary care setting were also introduced. ACT, Artesunate iv, and Artemether im, all are provided nationwide through the procurement system. For radical treatment, the recommendation in Indonesia is to add primaquine (PQ) to ACT for Plasmodium vivax and Plasmodium ovale infections to prevent relapses and for Plasmodium Falciparum infection to kill the gametocytes. These recommendations put hope to reduce malaria mortality to zero and eventually with other interventions will eliminate malaria from the country by 2030. The dissemination of this information is important for the policy to apply in practice across the country.

Malaria-induced changes in host odors enhance mosquito attraction

PubMed Central

De Moraes, Consuelo M.; Stanczyk, Nina M.; Betz, Heike S.; Pulido, Hannier; Sim, Derek G.; Read, Andrew F.; Mescher, Mark C.

2014-01-01

Vector-borne pathogens may alter traits of their primary hosts in ways that influence the frequency and nature of interactions between hosts and vectors. Previous work has reported enhanced mosquito attraction to host organisms infected with malaria parasites but did not address the mechanisms underlying such effects. Here we document malaria-induced changes in the odor profiles of infected mice (relative to healthy individuals) over the course of infection, as well as effects on the attractiveness of infected hosts to mosquito vectors. We observed enhanced mosquito attraction to infected mice during a key period after the subsidence of acute malaria symptoms, but during which mice remained highly infectious. This attraction corresponded to an overall elevation in the volatile emissions of infected mice observed during this period. Furthermore, data analyses—using discriminant analysis of principal components and random forest approaches—revealed clear differences in the composition of the volatile blends of infected and healthy individuals. Experimental manipulation of individual compounds that exhibited altered emission levels during the period when differential vector attraction was observed also elicited enhanced mosquito attraction, indicating that compounds being influenced by malaria infection status also mediate vector host-seeking behavior. These findings provide important insights into the cues that mediate vector attraction to hosts infected with transmissible stages of malaria parasites, as well as documenting characteristic changes in the odors of infected individuals that may have potential value as diagnostic biomarkers of infection. PMID:24982164

Malaria-induced changes in host odors enhance mosquito attraction.

PubMed

De Moraes, Consuelo M; Stanczyk, Nina M; Betz, Heike S; Pulido, Hannier; Sim, Derek G; Read, Andrew F; Mescher, Mark C

2014-07-29

Vector-borne pathogens may alter traits of their primary hosts in ways that influence the frequency and nature of interactions between hosts and vectors. Previous work has reported enhanced mosquito attraction to host organisms infected with malaria parasites but did not address the mechanisms underlying such effects. Here we document malaria-induced changes in the odor profiles of infected mice (relative to healthy individuals) over the course of infection, as well as effects on the attractiveness of infected hosts to mosquito vectors. We observed enhanced mosquito attraction to infected mice during a key period after the subsidence of acute malaria symptoms, but during which mice remained highly infectious. This attraction corresponded to an overall elevation in the volatile emissions of infected mice observed during this period. Furthermore, data analyses--using discriminant analysis of principal components and random forest approaches--revealed clear differences in the composition of the volatile blends of infected and healthy individuals. Experimental manipulation of individual compounds that exhibited altered emission levels during the period when differential vector attraction was observed also elicited enhanced mosquito attraction, indicating that compounds being influenced by malaria infection status also mediate vector host-seeking behavior. These findings provide important insights into the cues that mediate vector attraction to hosts infected with transmissible stages of malaria parasites, as well as documenting characteristic changes in the odors of infected individuals that may have potential value as diagnostic biomarkers of infection.

Wetlands and Malaria in the Amazon: Guidelines for the Use of Synthetic Aperture Radar Remote-Sensing

PubMed Central

Catry, Thibault; Li, Zhichao; Roux, Emmanuel; Herbreteau, Vincent; Dessay, Nadine

2018-01-01

The prevention and control of mosquito-borne diseases, such as malaria, are important health issues in tropical areas. Malaria transmission is a multi-scale process strongly controlled by environmental factors, and the use of remote-sensing data is suitable for the characterization of its spatial and temporal dynamics. Synthetic aperture radar (SAR) is well-adapted to tropical areas, since it is capable of imaging independent of light and weather conditions. In this study, we highlight the contribution of SAR sensors in the assessment of the relationship between vectors, malaria and the environment in the Amazon region. More specifically, we focus on the SAR-based characterization of potential breeding sites of mosquito larvae, such as man-made water collections and natural wetlands, providing guidelines for the use of SAR capabilities and techniques in order to optimize vector control and malaria surveillance. In light of these guidelines, we propose a framework for the production of spatialized indicators and malaria risk maps based on the combination of SAR, entomological and epidemiological data to support malaria risk prevention and control actions in the field. PMID:29518988

Wetlands and Malaria in the Amazon: Guidelines for the Use of Synthetic Aperture Radar Remote-Sensing.

PubMed

Catry, Thibault; Li, Zhichao; Roux, Emmanuel; Herbreteau, Vincent; Gurgel, Helen; Mangeas, Morgan; Seyler, Frédérique; Dessay, Nadine

2018-03-07

The prevention and control of mosquito-borne diseases, such as malaria, are important health issues in tropical areas. Malaria transmission is a multi-scale process strongly controlled by environmental factors, and the use of remote-sensing data is suitable for the characterization of its spatial and temporal dynamics. Synthetic aperture radar (SAR) is well-adapted to tropical areas, since it is capable of imaging independent of light and weather conditions. In this study, we highlight the contribution of SAR sensors in the assessment of the relationship between vectors, malaria and the environment in the Amazon region. More specifically, we focus on the SAR-based characterization of potential breeding sites of mosquito larvae, such as man-made water collections and natural wetlands, providing guidelines for the use of SAR capabilities and techniques in order to optimize vector control and malaria surveillance. In light of these guidelines, we propose a framework for the production of spatialized indicators and malaria risk maps based on the combination of SAR, entomological and epidemiological data to support malaria risk prevention and control actions in the field.

Asymptomatic malaria parasitaemia using rapid diagnostic test in unbooked pregnant women in rural Ondo-south district, Nigeria.

PubMed

Nwaneri, D U; Adeleye, O A; Ande, A B

2013-03-01

Malaria is a major contributor of maternal and peri-natal morbidity and mortality. The disease may be asymptomatic despite sequestration of parasitized red blood cells in the placental micro-circulation with antecedent complications. In such condition, it may also be difficult to identify the malaria parasite by the peripheral blood film microscopy, thus the need for use of simple but reliable tool for malaria parasite diagnosis. To determine the prevalence of asymptomatic malaria parasitaemia using the Rapid Diagnostic Test in pregnant unbooked women seen in a primary health centre during a malaria control campaign programme in rural Ondo-south, District Nigeria. Prevalence of asymptomatic malaria parasitaemia was 25.9%. Only 3 (3.5%) of the 85 women had the long lasting insecticide-treated nets. There was no significant association between malaria parasitaemia, and the age group, parity and gestation age. Given the high prevalence of asymptomatic malaria in pregnancy, routine screening for malaria at booking and scaling-up of other malaria control strategies such as the use of long lasting insecticidal-treated nets and intermittent preventive therapy for pregnant women are recommended.

When climate change couples social neglect: malaria dynamics in Panamá.

PubMed

Hurtado, Lisbeth Amarilis; Cáceres, Lorenzo; Chaves, Luis Fernando; Calzada, José E

2014-04-01

A major challenge of infectious disease elimination is the need to interrupt pathogen transmission across all vulnerable populations. Ethnic minorities are among the key vulnerable groups deserving special attention in disease elimination initiatives, especially because their lifestyle might be intrinsically linked to locations with high transmission risk. There has been a renewed interest in malaria elimination, which has ignited a quest to understand factors necessary for sustainable malaria elimination, highlighting the need for diverse approaches to address epidemiological heterogeneity across malaria transmission settings. An analysis of malaria incidence among the Guna Amerindians of Panamá over the last 34 years showed that this ethnic minority was highly vulnerable to changes that were assumed to not impact malaria transmission. Epidemic outbreaks were linked with El Niño Southern Oscillations and were sensitive to political instability and policy changes that did not ensure adequate attention to the malaria control needs of the Gunas. Our results illustrate how the neglect of minorities poses a threat to the sustainable control and eventual elimination of malaria in Central America and other areas where ethnic minorities do not share the benefits of malaria control strategies intended for dominant ethnic groups.

A morphometric and histological study of placental malaria shows significant changes to villous architecture in both Plasmodium falciparum and Plasmodium vivax infection

PubMed Central

2014-01-01

Background Malaria in pregnancy remains a major health problem. Placental malaria infection may cause pathophysiological changes in pregnancy and result in morphological changes to placental villi. Quantitative histomorphological image analysis of placental biopsies was performed to compare placental villous architecture between active or treated placental malaria cases and controls. Methods A total of 67 placentas were studied from three clinical groups: control patients who did not have malaria (n = 27), active (n = 14) and treated (n=26) malaria cases, including both Plasmodium falciparum and Plasmodium vivax infections. Image analysis of histological placental sections was performed using ImageJ software to measure the number and size (area) of terminal villi, perimeter measurement per villus and total perimeter per unit area, and number of capillaries per villus (vascularity). Histological features of placental malaria were scored and these results were correlated with malaria status and clinical outcomes. Results Villous size correlated with vascularity (p <0.0001) but was inversely correlated with observed villi per unit area, (p = 0.0001). Significantly greater villous area and vascularity was observed in UK controls. Indices of histological malaria infection were significantly greater in active versus treated malaria cases. Active placental malaria cases showed significantly smaller villous area (p <0.0084), vascularity (p <0.0139) and perimeter (p <0.0006) than treated malaria cases or controls, but significantly more villi per unit area (p <0.0001). Villous size in treated malaria cases was significantly larger than active placental malaria cases (p <0.001) and similar to controls. There was a significant relationship between villous number and anaemia at the time of infection (p <0.0034), but not placental weight, birth weight or gestational age at delivery. No differences were found between histology or villous morphology comparing infections with P. falciparum or P. vivax. Conclusions These results imply that villous size, perimeter and vascularity are acutely decreased during active placental malaria, decreasing the surface area available for gas exchange per villus. However the increased number of villi per unit area offsets this change and persists after treatment. Histopathological and villous architectural changes may be reversed by early detection and appropriate anti-malarial treatment. PMID:24386908

Malaria in India: The Center for the Study of Complex Malaria in India

PubMed Central

Das, Aparup; Anvikar, Anupkumar R.; Cator, Lauren J.; Dhiman, Ramesh C.; Eapen, Alex; Mishra, Neelima; Nagpal, Bhupinder N.; Nanda, Nutan; Raghavendra, Kamaraju; Read, Andrew F.; Sharma, Surya K.; Singh, Om P.; Singh, Vineeta; Sinnis, Photini; Srivastava, Harish C.; Sullivan, Steven A.; Sutton, Patrick L.; Thomas, Matthew B.; Carlton, Jane M.; Valecha, Neena

2012-01-01

Malaria is a major public health problem in India and one which contributes significantly to the overall malaria burden in Southeast Asia. The National Vector Borne Disease Control Program of India reported ~1.6 million cases and ~1100 malaria deaths in 2009. Some experts argue that this is a serious underestimation and that the actual number of malaria cases per year is likely between 9 and 50 times greater, with an approximate 13-fold underestimation of malaria-related mortality. The difficulty in making these estimations is further exacerbated by (i) highly variable malaria eco-epidemiological profiles, (ii) the transmission and overlap of multiple Plasmodium species and Anopheles vectors, (iii) increasing antimalarial drug resistance and insecticide resistance, and (iv) the impact of climate change on each of these variables. Simply stated, the burden of malaria in India is complex. Here we describe plans for a Center for the Study of Complex Malaria in India (CSCMi), one of ten International Centers of Excellence in Malaria Research (ICEMRs) located in malarious regions of the world recently funded by the National Institute of Allergy and Infectious Diseases, National Institutes of Health. The CSCMi is a close partnership between Indian and United States scientists, and aims to address major gaps in our understanding of the complexity of malaria in India, including changing patterns of epidemiology, vector biology and control, drug resistance, and parasite genomics. We hope that such a multidisciplinary approach that integrates clinical and field studies with laboratory, molecular, and genomic methods will provide a powerful combination for malaria control and prevention in India. PMID:22142788

Controlled human malaria infection trials: How tandems of trust and control construct scientific knowledge.

PubMed

Bijker, Else M; Sauerwein, Robert W; Bijker, Wiebe E

2016-02-01

Controlled human malaria infections are clinical trials in which healthy volunteers are deliberately infected with malaria under controlled conditions. Controlled human malaria infections are complex clinical trials: many different groups and institutions are involved, and several complex technologies are required to function together. This functioning together of technologies, people, and institutions is under special pressure because of potential risks to the volunteers. In this article, the authors use controlled human malaria infections as a strategic research site to study the use of control, the role of trust, and the interactions between trust and control in the construction of scientific knowledge. The authors argue that tandems of trust and control play a central role in the successful execution of clinical trials and the construction of scientific knowledge. More specifically, two aspects of tandems of trust and control will be highlighted: tandems are sites where trust and control coproduce each other, and tandems link the personal, the technical, and the institutional domains. Understanding tandems of trust and control results in setting some agendas for both clinical trial research and science and technology studies.

LH750 hematology analyzers to identify malaria and dengue and distinguish them from other febrile illnesses.

PubMed

Sharma, P; Bhargava, M; Sukhachev, D; Datta, S; Wattal, C

2014-02-01

Tropical febrile illnesses such as malaria and dengue are challenging to differentiate clinically. Automated cellular indices from hematology analyzers may afford a preliminary rapid distinction. Blood count and VCS parameters from 114 malaria patients, 105 dengue patients, and 105 febrile controls without dengue or malaria were analyzed. Statistical discriminant functions were generated, and their diagnostic performances were assessed by ROC curve analysis. Three statistical functions were generated: (i) malaria-vs.-controls factor incorporating platelet count and standard deviations of lymphocyte volume and conductivity that identified malaria with 90.4% sensitivity, 88.6% specificity; (ii) dengue-vs.-controls factor incorporating platelet count, lymphocyte percentage and standard deviation of lymphocyte conductivity that identified dengue with 81.0% sensitivity and 77.1% specificity; and (iii) febrile-controls-vs.-malaria/dengue factor incorporating mean corpuscular hemoglobin concentration, neutrophil percentage, mean lymphocyte and monocyte volumes, and standard deviation of monocyte volume that distinguished malaria and dengue from other febrile illnesses with 85.1% sensitivity and 91.4% specificity. Leukocyte abnormalities quantitated by automated analyzers successfully identified malaria and dengue and distinguished them from other fevers. These economic discriminant functions can be rapidly calculated by analyzer software programs to generate electronic flags to trigger-specific testing. They could potentially transform diagnostic approaches to tropical febrile illnesses in cost-constrained settings. © 2013 John Wiley & Sons Ltd.

Elimination of Plasmodium vivax Malaria in Azerbaijan

PubMed Central

Mammadov, Suleyman; Gasimov, Elkhan; Kurdova-Mintcheva, Rossitza; Wongsrichanalai, Chansuda

2016-01-01

Azerbaijan in the south caucasus region of far southeastern Europe has a long history of malaria endemicity but just successfully eliminated local transmission. After a period of relatively stable malaria situation (1960–1970), the country witnessed an epidemic followed by a series of outbreaks of various magnitudes in the following two decades, all caused by Plasmodium vivax. Compared with 1993, the number of malaria cases in the country jumped 29 times in 1994, 123 times in 1995, and 571 times in 1996 at the peak of the epidemic, when 13,135 cases were officially registered. Incidence rate increased dramatically from 0.2/100,000 population in 1991 to over 17/100,000 population in 1996. Scaled-up malaria control led to the containment of the epidemic and to a dramatic decrease of malaria burden nationwide. Azerbaijan has applied contemporary, complex control and surveillance strategies and approaches and is currently in the prevention of reintroduction phase. This article describes Azerbaijan's public health experience in conducting malaria control and elimination interventions over several decades until 2013 when the country reached an important milestone—no indigenous malaria cases were recorded. PMID:27708184

Shifting from presumptive to test-based management of malaria - technical basis and implications for malaria control in Ghana.

PubMed

Baiden, F; Malm, K; Bart-Plange, C; Hodgson, A; Chandramohan, D; Webster, J; Owusu-Agyei, S

2014-06-01

The presumptive approach was the World Health Organisation (WHO) recommended to the management of malaria for many years and this was incorporated into syndromic guidelines such as the Integrated Management of Childhood Illnesses (IMCI). In early 2010 however, WHO issued revised treatment guidelines that call for a shift from the presumptive to the test-based approach. Practically, this implies that in all suspected cases, the diagnosis of uncomplicated malaria should be confirmed using rapid test before treatment is initiated. This revision effectively brings to an end an era of clinical practice that span several years. Its implementation has important implications for the health systems in malaria-endemic countries. On the basis of research in Ghana and other countries, and evidence from program work, the Ghana National Malaria Control Program has issued revised national treatment guidelines that call for implementation of test-based management of malaria in all cases, and across all age groups. This article reviews the evidence and the technical basis for the shift to test-based management and examines the implications for malaria control in Ghana.

Malaria epidemiology in low-endemicity areas of the northern coast of Ecuador: high prevalence of asymptomatic infections.

PubMed

Sáenz, Fabián E; Arévalo-Cortés, Andrea; Valenzuela, Gabriela; Vallejo, Andrés F; Castellanos, Angélica; Poveda-Loayza, Andrea C; Gutierrez, Juan B; Alvarez, Alvaro; Yan, Yi Heng; Benavides, Yoldy; Castro, Luis Enrique; Arévalo-Herrera, Myriam; Herrera, Sócrates

2017-07-26

The recent scale-up in malaria control measures in Latin America has resulted in a significant decrease in the number of reported cases in several countries including Ecuador, where it presented a low malaria incidence in recent years (558 reported cases in 2015) with occasional outbreaks of both Plasmodium falciparum and Plasmodium vivax in the coastal and Amazonian regions. This success in malaria control in recent years has led Ecuador to transition its malaria policy from control to elimination. This study evaluated the general knowledge, attitude and practices (KAP) about malaria, as well as its prevalence in four communities of an endemic area in northwest Ecuador. A total of 258 interviews to assess KAP in the community indicated that most people in the study area have a basic knowledge about the disease but did not use to contribute to its control. Six hundred and forty-eight blood samples were collected and analysed by thick blood smear and real-time PCR. In addition, the distribution of the infections was mapped in the study communities. Although, no parasites were found by microscopy, by PCR the total malaria prevalence was 7.5% (6.9% P. vivax and 0.6% P. falciparum), much higher than expected and comparable to that reported in endemic areas of neighbouring countries with higher malaria transmission. Serology using ELISA and immunofluorescence indicated 27% respondents for P. vivax and 22% respondents for P. falciparum. Results suggest that despite a great malaria reduction in Ecuador, transition from control to elimination would demand further improvement in malaria diagnostics, including active case detection to identify and treat parasite asymptomatic carriers, as well as community participation in its elimination.

Effectiveness and impact of the cross-border healthcare model as implemented by non-governmental organizations: case study of the malaria control programs by health poverty action on the China-Myanmar border.

PubMed

Zhang, Jun; Dong, Jia-Qiang; Li, Jia-Ying; Zhang, Yue; Tian, Yang-Hui; Sun, Xiao-Ying; Zhang, Guang-Yun; Li, Qing-Pu; Xu, Xiao-Yu; Cai, Tao

2016-09-01

In the Yunnan province of China, 18 counties in six prefectures border Myanmar. Due to its particular combination of geographic features, climate conditions, and cultural landscape, the area provides a suitable environment for the spread of insect-borne diseases such as malaria. In five identified Myanmar Special Regions along the China-Myanmar border, economic development is lagging, people live in extreme poverty, and the healthcare system is fragile. Coupled with political and other reasons, this precludes malaria control work to be effectively carried out in Myanmar, resulting in a heavy burden of the disease. Frequent population movements and favorable conditions for malaria transmission on the border fuel difficulties in controlling and eliminating the spread of the disease in the area. To reduce the prevalence of malaria in the China-Myanmar border area and improve healthcare services for local residents in this particular environment, Health Poverty Action (HPA) has provided malaria aid in the area since the beginning of 2006, as a sub-recipient of the China Global Fund Malaria Programs. In this case study, we examined HPA's activities as part of its malaria control programs in the area, analyzed and summarized the effectiveness and impact of the cross-border healthcare model as implemented by non-governmental organizations, and put forward suggestions for cross-border health aid models and for the prevention of malaria transmission in the Greater Mekong Subregion. HPA had carried out a great quantity of successful malaria control activities in border areas between China and Myanmar, strengthened the partnership and established the collaboration, coordination and cooperation channels among stakeholders. HPA has laid good groundwork and developed its valuable model that could be highlighted and referenced.

Host population persistence in the face of introduced vector-borne diseases: Hawaii amakihi and avian malaria

PubMed Central

Woodworth, Bethany L.; Atkinson, Carter T.; LaPointe, Dennis A.; Hart, Patrick J.; Spiegel, Caleb S.; Tweed, Erik J.; Henneman, Carlene; LeBrun, Jaymi; Denette, Tami; DeMots, Rachel; Kozar, Kelly L.; Triglia, Dennis; Lease, Dan; Gregor, Aaron; Smith, Tom; Duffy, David

2005-01-01

The past quarter century has seen an unprecedented increase in the number of new and emerging infectious diseases throughout the world, with serious implications for human and wildlife populations. We examined host persistence in the face of introduced vector-borne diseases in Hawaii, where introduced avian malaria and introduced vectors have had a negative impact on most populations of Hawaiian forest birds for nearly a century. We studied birds, parasites, and vectors in nine study areas from 0 to 1,800 m on Mauna Loa Volcano, Hawaii from January to October, 2002. Contrary to predictions of prior work, we found that Hawaii amakihi (Hemignathus virens), a native species susceptible to malaria, comprised from 24.5% to 51.9% of the avian community at three low-elevation forests (55–270 m). Amakihi were more abundant at low elevations than at disease-free high elevations, and were resident and breeding there. Infection rates were 24–40% by microscopy and 55–83% by serology, with most infected individuals experiencing low-intensity, chronic infections. Mosquito trapping and diagnostics provided strong evidence for year-round local transmission. Moreover, we present evidence that Hawaii amakihi have increased in low elevation habitats on southeastern Hawaii Island over the past decade. The recent emergent phenomenon of recovering amakihi populations at low elevations, despite extremely high prevalence of avian malaria, suggests that ecological or evolutionary processes acting on hosts or parasites have allowed this species to recolonize low-elevation habitats. A better understanding of the mechanisms allowing coexistence of hosts and parasites may ultimately lead to tools for mitigating disease impacts on wildlife and human populations. PMID:15668377

Host population persistence in the face of introduced vector-borne diseases: Hawaii amakihi and avian malaria.

PubMed

Woodworth, Bethany L; Atkinson, Carter T; Lapointe, Dennis A; Hart, Patrick J; Spiegel, Caleb S; Tweed, Erik J; Henneman, Carlene; Lebrun, Jaymi; Denette, Tami; Demots, Rachel; Kozar, Kelly L; Triglia, Dennis; Lease, Dan; Gregor, Aaron; Smith, Tom; Duffy, David

2005-02-01

The past quarter century has seen an unprecedented increase in the number of new and emerging infectious diseases throughout the world, with serious implications for human and wildlife populations. We examined host persistence in the face of introduced vector-borne diseases in Hawaii, where introduced avian malaria and introduced vectors have had a negative impact on most populations of Hawaiian forest birds for nearly a century. We studied birds, parasites, and vectors in nine study areas from 0 to 1,800 m on Mauna Loa Volcano, Hawaii from January to October, 2002. Contrary to predictions of prior work, we found that Hawaii amakihi (Hemignathus virens), a native species susceptible to malaria, comprised from 24.5% to 51.9% of the avian community at three low-elevation forests (55-270 m). Amakihi were more abundant at low elevations than at disease-free high elevations, and were resident and breeding there. Infection rates were 24-40% by microscopy and 55-83% by serology, with most infected individuals experiencing low-intensity, chronic infections. Mosquito trapping and diagnostics provided strong evidence for year-round local transmission. Moreover, we present evidence that Hawaii amakihi have increased in low elevation habitats on southeastern Hawaii Island over the past decade. The recent emergent phenomenon of recovering amakihi populations at low elevations, despite extremely high prevalence of avian malaria, suggests that ecological or evolutionary processes acting on hosts or parasites have allowed this species to recolonize low-elevation habitats. A better understanding of the mechanisms allowing coexistence of hosts and parasites may ultimately lead to tools for mitigating disease impacts on wildlife and human populations.

Host population persistence in the face of introduced vector-borne diseases: Hawaii amakihi and avian malaria

USGS Publications Warehouse

Woodworth, B.L.; Atkinson, C.T.; Lapointe, D.A.; Hart, P.J.; Spiegel, C.S.; Tweed, E.J.; Henneman, C.; LeBrun, J.; Denette, T.; DeMots, R.; Kozar, K.L.; Triglia, D.; Lease, Dan; Gregor, A.; Smith, T.; Duffy, D.

2005-01-01

The past quarter century has seen an unprecedented increase in the number of new and emerging infectious diseases throughout the world, with serious implications for human and wildlife populations. We examined host persistence in the face of introduced vector-borne diseases in Hawaii, where introduced avian malaria and introduced vectors have had a negative impact on most populations of Hawaiian forest birds for nearly a century. We studied birds, parasites, and vectors in nine study areas from 0 to 1,800 m on Mauna Loa Volcano, Hawaii from January to October, 2002. Contrary to predictions of prior work, we found that Hawaii amakihi (Hemignathus virens), a native species susceptible to malaria, comprised from 24.5% to 51.9% of the avian community at three low-elevation forests (55-270 m). Amakihi were more abundant at low elevations than at disease-free high elevations, and were resident and breeding there. Infection rates were 24-40% by microscopy and 55-83% by serology, with most infected individuals experiencing low-intensity, chronic infections. Mosquito trapping and diagnostics provided strong evidence for year-round local transmission. Moreover, we present evidence that Hawaii amakihi have increased in low elevation habitats on south-eastern Hawaii Island over the past decade. The recent emergent phenomenon of recovering amakihi populations at low elevations, despite extremely high prevalence of avian malaria, suggests that ecological or evolutionary processes acting on hosts or parasites have allowed this species to recolonize low-elevation habitats. A better understanding of the mechanisms allowing coexistence of hosts and parasites may ultimately lead to tools for mitigating disease impacts on wildlife and human populations.

Thermal constraints to the sporogonic development and altitudinal distribution of avian malaria Plasmodium relictum in Hawai'i.

PubMed

LaPointe, Dennis A; Goff, M Lee; Atkinson, Carter T

2010-04-01

More than half of the Hawaiian honeycreepers (Drepanidinae) known from historical records are now extinct. Introduced mosquito-borne disease, in particular the avian malaria Plasmodium relictum , has been incriminated as a leading cause of extinction during the 20th century and a major limiting factor in the recovery of remaining species populations. Today, most native Hawaiian bird species reach their highest densities and diversity in high elevation (>1,800 m above sea level) forests. We determined the thermal requirements for sporogonic development of P. relictum in the natural vector, Culex quinquefasciatus , and assessed the current distribution of native bird species in light of this information. Sporogonic development was completed at constant laboratory and mean field temperatures between 30 and 17 C, but development, prevalence, and intensity decreased significantly below 21 C. Using a degree-day (DD) model, we estimated a minimum threshold temperature of 12.97 C and a thermal requirement of 86.2 DD as necessary to complete development. Predicted (adiabatic lapse-rate) and observed summer threshold isotherm (13 C) correspond to the elevation of high forest refuges on the islands of Maui and Hawai'i. Our data support the hypothesis that avian malaria currently restricts the altitudinal distribution of Hawaiian honeycreeper populations and provide an ecological explanation for the absence of disease at high elevation.

Effects of Reservoir Characteristics on Malaria and its vector Abundance: A Case Study of the Bongo District of Ghana

NASA Astrophysics Data System (ADS)

Ofosu, E.; Awuah, E.; Annor, F. O.

2009-04-01

In the seven (7) administrative zones of the Bongo District of the Upper East Region of Ghana, the occurrences of malaria and relative abundance of the principal malaria vector, Anopheles species, were studied as a function of the presence and characteristics of reservoirs during the rainy season. Case studies in the sub-Sahara Africa indicate that malaria transmission may increase decrease or remain largely unchanged as a consequence of reservoir presence. Analysis made, shows that the distance from reservoir to settlement and surface area of reservoirs significantly affected adult Anopheles mosquito abundance. Percentage of inhabitants using insecticide treated nets, livestock population density, human population density and Anopheles mosquito abundance significantly affected the occurrence of malaria. The results suggest that vector control targeted at reservoir characteristics and larval control, and supplemented by high patronage of insecticide treated nets may be an effective approach for epidemic malaria control in the Bongo District. Key Words: Bongo District, Reservoir, Anopheles species, Malaria, Vector abundance.

Implementation of Malaria Dynamic Models in Municipality Level Early Warning Systems in Colombia. Part I: Description of Study Sites

PubMed Central

Ruiz, Daniel; Cerón, Viviana; Molina, Adriana M.; Quiñónes, Martha L.; Jiménez, Mónica M.; Ahumada, Martha; Gutiérrez, Patricia; Osorio, Salua; Mantilla, Gilma; Connor, Stephen J.; Thomson, Madeleine C.

2014-01-01

As part of the Integrated National Adaptation Pilot project and the Integrated Surveillance and Control System, the Colombian National Institute of Health is working on the design and implementation of a Malaria Early Warning System framework, supported by seasonal climate forecasting capabilities, weather and environmental monitoring, and malaria statistical and dynamic models. In this report, we provide an overview of the local ecoepidemiologic settings where four malaria process-based mathematical models are currently being implemented at a municipal level. The description includes general characteristics, malaria situation (predominant type of infection, malaria-positive cases data, malaria incidence, and seasonality), entomologic conditions (primary and secondary vectors, mosquito densities, and feeding frequencies), climatic conditions (climatology and long-term trends), key drivers of epidemic outbreaks, and non-climatic factors (populations at risk, control campaigns, and socioeconomic conditions). Selected pilot sites exhibit different ecoepidemiologic settings that must be taken into account in the development of the integrated surveillance and control system. PMID:24891460

Using Decision Analysis to Improve Malaria Control Policy Making

PubMed Central

Kramer, Randall; Dickinson, Katherine L.; Anderson, Richard M.; Fowler, Vance G.; Miranda, Marie Lynn; Mutero, Clifford M.; Saterson, Kathryn A.; Wiener, Jonathan B.

2013-01-01

Malaria and other vector-borne diseases represent a significant and growing burden in many tropical countries. Successfully addressing these threats will require policies that expand access to and use of existing control methods, such as insecticide-treated bed nets and artemesinin combination therapies for malaria, while weighing the costs and benefits of alternative approaches over time. This paper argues that decision analysis provides a valuable framework for formulating such policies and combating the emergence and re-emergence of malaria and other diseases. We outline five challenges that policy makers and practitioners face in the struggle against malaria, and demonstrate how decision analysis can help to address and overcome these challenges. A prototype decision analysis framework for malaria control in Tanzania is presented, highlighting the key components that a decision support tool should include. Developing and applying such a framework can promote stronger and more effective linkages between research and policy, ultimately helping to reduce the burden of malaria and other vector-borne diseases. PMID:19356821

Genetic Surveillance Detects Both Clonal and Epidemic Transmission of Malaria following Enhanced Intervention in Senegal

PubMed Central

Séne, Papa Diogoye; Park, Danny C.; Neafsey, Daniel E.; Schaffner, Stephen F.; Hamilton, Elizabeth J.; Lukens, Amanda K.; Van Tyne, Daria; Mboup, Souleymane; Sabeti, Pardis C.; Ndiaye, Daouda; Wirth, Dyann F.

2013-01-01

Using parasite genotyping tools, we screened patients with mild uncomplicated malaria seeking treatment at a clinic in Thiès, Senegal, from 2006 to 2011. We identified a growing frequency of infections caused by genetically identical parasite strains, coincident with increased deployment of malaria control interventions and decreased malaria deaths. Parasite genotypes in some cases persisted clonally across dry seasons. The increase in frequency of genetically identical parasite strains corresponded with decrease in the probability of multiple infections. Further, these observations support evidence of both clonal and epidemic population structures. These data provide the first evidence of a temporal correlation between the appearance of identical parasite types and increased malaria control efforts in Africa, which here included distribution of insecticide treated nets (ITNs), use of rapid diagnostic tests (RDTs) for malaria detection, and deployment of artemisinin combination therapy (ACT). Our results imply that genetic surveillance can be used to evaluate the effectiveness of disease control strategies and assist a rational global malaria eradication campaign. PMID:23593309

Individual and household characteristics of persons with Plasmodium falciparum malaria in sites with varying endemicities in Kinshasa Province, Democratic Republic of the Congo.

PubMed

Mwandagalirwa, Melchior Kashamuka; Levitz, Lauren; Thwai, Kyaw L; Parr, Jonathan B; Goel, Varun; Janko, Mark; Tshefu, Antoinette; Emch, Michael; Meshnick, Steven R; Carrel, Margaret

2017-11-09

The Democratic Republic of the Congo (DRC) bears a large share of global malaria burden despite efforts to control and eliminate the disease. More detailed understanding of individual and household level characteristics associated with malaria are needed, as is an understanding of how these characteristics vary spatiotemporally and across different community-level malaria endemicities. An ongoing study in Kinshasa Province is designed to address gaps in prior malaria surveillance in the DRC by monitoring malaria across seasons, age groups and in high and low malaria sites. Across seven sites, 242 households and 1591 individuals are participating in the study. Results of the enrollment questionnaire, rapid diagnostic tests and PCR testing of dried blood spots are presented. Overall malaria prevalence in the study cohort is high, 27% by rapid diagnostic test and 31% by polymerase chain reaction, and malaria prevalence is highly varied across very small geographic distances. Malaria prevalence is highest in children aged 6-15. While the majority of households own bed nets, bed net usage is less than 50%. The study cohort will provide an understanding of how malaria persists in populations that have varying environmental exposures, varying community-level malaria, and varying access to malaria control efforts.

Coquillettidia (Culicidae, Diptera) mosquitoes are natural vectors of avian malaria in Africa

PubMed Central

2009-01-01

Background The mosquito vectors of Plasmodium spp. have largely been overlooked in studies of ecology and evolution of avian malaria and other vertebrates in wildlife. Methods Plasmodium DNA from wild-caught Coquillettidia spp. collected from lowland forests in Cameroon was isolated and sequenced using nested PCR. Female Coquillettidia aurites were also dissected and salivary glands were isolated and microscopically examined for the presence of sporozoites. Results In total, 33% (85/256) of mosquito pools tested positive for avian Plasmodium spp., harbouring at least eight distinct parasite lineages. Sporozoites of Plasmodium spp. were recorded in salivary glands of C. aurites supporting the PCR data that the parasites complete development in these mosquitoes. Results suggest C. aurites, Coquillettidia pseudoconopas and Coquillettidia metallica as new and important vectors of avian malaria in Africa. All parasite lineages recovered clustered with parasites formerly identified from several bird species and suggest the vectors capability of infecting birds from different families. Conclusion Identifying the major vectors of avian Plasmodium spp. will assist in understanding the epizootiology of avian malaria, including differences in this disease distribution between pristine and disturbed landscapes. PMID:19664282

Antimalarial plants of northeast India: An overview.

PubMed

Shankar, Rama; Deb, Sourabh; Sharma, B K

2012-01-01

The need for an alternative drug for malaria initiated intensive efforts for developing new antimalarials from indigenous plants. The information from different tribal communities of northeast India along with research papers, including books, journals and documents of different universities and institutes of northeast India was collected for information on botanical therapies and plant species used for malaria. Sixty-eight plant species belonging to 33 families are used by the people of northeast India for the treatment of malaria. Six plant species, namely, Alstonia scholaris, Coptis teeta, Crotolaria occulta, Ocimum sanctum, Polygala persicariaefolia, Vitex peduncularis, have been reported by more than one worker from different parts of northeast India. The species reported to be used for the treatment of malaria were either found around the vicinity of their habitation or in the forest area of northeast India. The most frequently used plant parts were leaves (33%), roots (31%), and bark and whole plant (12%). The present study has compiled and enlisted the antimalarial plants of northeast India, which would help future workers to find out the suitable antimalarial plants by thorough study.

Black cohosh Actaea racemosa: an annotated bibliography

Treesearch

Mary L. Predny; Patricia De Angelis; James L. Chamberlain

2006-01-01

Black cohosh (Actaea racemosa, Syn.: Cimicifuga racemosa), a member of the buttercup family (Ranunculaceae), is an erect perennial found in rich cove forests of Eastern North America from Georgia to Ontario. Native Americans used black cohosh for a variety of ailments including rheumatism, malaria, sore throats, and complications...

Keys to success for a school-based malaria control program in primary schools in Thailand.

PubMed

Okabayashi, Hironori; Thongthien, Pimpimon; Singhasvanon, Pratap; Waikagul, Jitra; Looareesuwan, Sornchai; Jimba, Masamine; Kano, Shigeyuki; Kojima, Somei; Takeuchi, Tsutomu; Kobayashi, Jun; Tateno, Seiki

2006-06-01

School-based malaria control has been recognized as a new approach for the control of this disease in the Greater Mekong Subregion since 2000. We evaluated a school-based malaria control program near the western border of Thailand using a before-after intervention study. The major intervention activities included teacher training with specialized malaria teaching materials and participatory learning methods. The target population was 17 school principals, 111 teachers and 852 schoolchildren of grade 3, 4, and 5 in 17 schools. After the intervention, the teachers taught about malaria more actively than before. The teachers who could design a lesson plan on malaria increased from 30.7% to 47.7% (p=0.015) and the teachers who had taught about malaria increased from 71.9% to 84.3% (p=0.035). As a result of the program, the schoolchildren changed their behavior positively towards malaria prevention with significant difference in 6 of 7 questions. For example, the schoolchildren 'who always took care of mosquito bites' increased from 42.7% to 62.1% (p<0.001) and the schoolchildren 'who always reported their parents or teachers when they had fever' increased from 36.0% to 56.0% (p<0.001). In conclusion, the keys to a successful intervention lie in good teaching materials and a participatory approach utilizing the well-established Thailand's school health system. Beyond Thailand, school-based malaria control could be applied to other Greater Mekong Subregion countries with careful analysis of school health context in each country.

An ethnobotanical study of anti-malarial plants among indigenous people on the upper Negro River in the Brazilian Amazon.

PubMed

Frausin, Gina; Hidalgo, Ari de Freitas; Lima, Renata Braga Souza; Kinupp, Valdely Ferreira; Ming, Lin Chau; Pohlit, Adrian Martin; Milliken, William

2015-11-04

In this article we present the plants used for the treatment of malaria and associated symptoms in Santa Isabel do Rio Negro in the Brazilian Amazon. The region has important biological and cultural diversities including more than twenty indigenous ethnic groups and a strong history in traditional medicine. The aims of this study are to survey information in the Baniwa, Baré, Desana, Piratapuia, Tariana, Tukano, Tuyuca and Yanomami ethnic communities and among caboclos (mixed-ethnicity) on (a) plant species used for the treatment of malaria and associated symptoms, (b) dosage forms and (c) distribution of these anti-malarial plants in the Amazon. Information was obtained through classical ethnobotanical and ethnopharmacological methods from interviews with 146 informants in Santa Isabel municipality on the upper Negro River, Brazil. Fifty-five mainly native neotropical plant species from 34 families were in use. The detailed uses of these plants were documented. The result was 187 records (64.5%) of plants for the specific treatment of malaria, 51 records (17.6%) of plants used in the treatment of liver problems and 29 records (10.0%) of plants used in the control of fevers associated with malaria. Other uses described were blood fortification ('dar sangue'), headache and prophylaxis. Most of the therapeutic preparations were decoctions and infusions based on stem bark, root bark and leaves. These were administered by mouth. In some cases, remedies were prepared with up to three different plant species. Also, plants were used together with other ingredients such as insects, mammals, gunpowder and milk. This is the first study on the anti-malarial plants from this region of the Amazon. Aspidosperma spp. and Ampelozizyphus amazonicus Ducke were the most cited species in the communities surveyed. These species have experimental proof supporting their anti-malarial efficacy. The dosage of the therapeutic preparations depends on the kind of plant, quantity of plant material available, the patient's age (children and adults) and the local expert. The treatment time varies from a single dose to up to several weeks. Most anti-malarial plants are domesticated or grow spontaneously. They are grown in home gardens, open areas near the communities, clearings and secondary forests, and wild species grow in areas of seasonally flooded wetlands and terra firme ('solid ground') forest, in some cases in locations that are hard to access. Traditional knowledge of plants was found to be falling into disuse presumably as a consequence of the local official health services that treat malaria in the communities using commercial drugs. Despite this, some species are used in the prevention of this disease and also in the recovery after using conventional anti-malarial drugs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Malaria burden and control in Bangladesh and prospects for elimination: an epidemiological and economic assessment.

PubMed

Haque, Ubydul; Overgaard, Hans J; Clements, Archie C A; Norris, Douglas E; Islam, Nazrul; Karim, Jahirul; Roy, Shyamal; Haque, Waziul; Kabir, Moktadir; Smith, David L; Glass, Gregory E

2014-02-01

Malaria is endemic in 13 of 64 districts in Bangladesh. About 14 million people are at risk. Some evidence suggests that the prevalence of malaria in Bangladesh has decreased since the the Global Fund to Fight AIDS, Tuberculosis and Malaria started to support the National Malaria Control Program (NMCP) in 2007. We did an epidemiological and economic assessment of malaria control in Bangladesh. We obtained annually reported, district-level aggregated malaria case data and information about disbursed funds from the NMCP. We used a Poisson regression model to examine the associations between total malaria, severe malaria, malaria-attributable mortality, and insecticide-treated net coverage. We identified and mapped malaria hotspots using the Getis-Ord Gi* statistic. We estimated the cost-effectiveness of the NMCP by estimating the cost per confirmed case, cost per treated case, and cost per person of insecticide-treated net coverage. During the study period (from Jan 1, 2008, to Dec 31, 2012) there were 285,731 confirmed malaria cases. Malaria decreased from 6.2 cases per 1000 population in 2008, to 2.1 cases per 1000 population in 2012. Prevalence of all malaria decreased by 65% (95% CI 65-66), severe malaria decreased by 79% (78-80), and malaria-associated mortality decreased by 91% (83-95). By 2012, there was one insecticide-treated net for every 2.6 individuals (SD 0.20). Districts with more than 0.5 insecticide-treated nets per person had a decrease in prevalence of 21% (95% CI 19-23) for all malaria, 25% (17-32) for severe malaria, and 76% (35-91) for malaria-associated mortality among all age groups. Malaria hotspots remained in the highly endemic districts in the Chittagong Hill Tracts. The cost per diagnosed case was US$0.39 (SD 0.02) and per treated case was $0.51 (0.27); $0.05 (0.04) was invested per person per year for health education and $0.68 (0.30) was spent per person per year for insecticide-treated net coverage. Malaria elimination is an achievable prospect in Bangladesh and failure to push for elimination nearly ensures a resurgence of disease. Consistent financing is needed to avoid resurgence and maintain elimination goals. None. Copyright © 2014 Haque et al. Open Access article distributed under the terms of CC BY-NC-ND. Published by .. All rights reserved.

Malaria burden and costs of intensified control in Bhutan, 2006-14: an observational study and situation analysis.

PubMed

Wangdi, Kinley; Banwell, Cathy; Gatton, Michelle L; Kelly, Gerard C; Namgay, Rinzin; Clements, Archie C A

2016-05-01

The number of malaria cases has fallen in Bhutan in the past two decades, and the country has a goal of complete elimination of malaria by 2016. The aims of this study are to ascertain the trends and burden of malaria, the costs of intensified control activities, the main donors of funding for the control activities, and the costs of different preventive measures in the pre-elimination phase (2006-14) in Bhutan. We undertook a descriptive analysis of malaria surveillance data from 2006 to 2014, using data from the Vector-borne Disease Control Programme (VDCP) run by the Department of Public Health of Bhutan's Ministry of Health. Malaria morbidity and mortality in local Bhutanese people and foreign nationals were analysed. The cost of different control and preventive measures were calculated, and the average numbers of long-lasting insecticidal nests per person were estimated. A total of 5491 confirmed malaria cases occurred in Bhutan between 2006 and 2014. By 2013, there was an average of one long-lasting insecticidal net for every 1·51 individuals. The cost of procuring long-lasting insecticidal nets accounted for more than 90% of the total cost of prevention measures. The Global Fund to Fight AIDS, Tuberculosis and Malaria was the main international donor, accounting for more than 80% of the total funds. The malaria burden in Bhutan decreased significantly during the study period with high coverage of long-lasting insecticidal nets. The foreseeable challenges that require national attention to maintain a malaria-free status after elimination are importation of malaria, especially from India; continued protection of the population in endemic districts through complete coverage with long-lasting insecticidal nets and indoor residual spraying; and exploration of local funding modalities post-elimination in the event of a reduction in international funding. None. Copyright © 2016 Wangdi et al. Open Access article distributed under the terms of CC BY. Published by Elsevier Ltd.. All rights reserved.

[Current malaria situation in Turkey].

PubMed

Gockchinar, T; Kalipsi, S

2001-01-01

Geographically, Turkey is situated in an area where malaria is very risky. The climatic conditions in the region are suitable for the malaria vector to proliferate. Due to agricultural infrastructural changes, GAP and other similar projects, insufficient environmental conditions, urbanization, national and international population moves, are a key to manage malaria control activities. It is estimated that malaria will be a potential danger for Turkey in the forthcoming years. The disease is located largely in south-eastern Anatolia. The Diyarbakir, Batman, Sanliurfa, Siirt, and Mardin districts are the most affected areas. In western districts, like Aydin and Manisa, an increase in the number of indigenous cases can be observed from time to time. This is due to workers moving from malaria districts to western parts to final work. Since these workers cannot be controlled, the population living in these regions get infected from indigenous cases. There were 84,345 malaria cases in 1994 and 82,096 in 1995, they decreased to 60,884 in 1996 and numbered 35,456 in 1997. They accounted for 36,842 and 20,963 in 1998 and 1999, respectively. In Turkey there are almost all cases of P. vivax malaria. There are also P. vivax and P. falciparum malaria cases coming from other countries: There were 321 P. vivax cases, including 2 P. falciparum ones, arriving to Turkey from Iraq in 1995. The P. vivax malaria cases accounted for 229 in 1996, and 67, cases P. vivax including 12 P. falciparum cases, in 1997, and 4 P. vivax cases in 1998 that came from that country. One P. vivax case entered Turkey from Georgia in 1998. The cause of higher incidence of P. vivax cases in 1995, it decreasing in 1999, is the lack of border controls over workers coming to Turkey. The other internationally imported cases are from Syria, Sudan, Pakistan, Afghanistan, Nigeria, India, Azerbaijan, Malaysia, Ghana, Indonesia, Yemen. Our examinations have shown that none of these internationally imported cases are important in transmitting the diseases. The districts where malaria cases occur are the places where population moves are rapid, agriculture is the main occupation, the increase in the population is high and the education/cultural level is low. Within years, the districts with high malaria cases also differ. Before 1990 Cucurova and Amikova were the places that showed the highest incidence of malaria. Since 1990, the number of cases from south-eastern Anatolia has started to rise. The main reasons for this change are a comprehensive malaria prevention programme, regional development, developed agricultural systems, and lower population movements. The 1999 statistical data indicate that 83 and 17% of all malaria cases are observed in the GAP and other districts, respectively. The distribution of malaria cases in Turkey differs by months and climatic conditions. The incidence of malaria starts to rise in March, reaching its peak in July, August and September, begins to fall in October. In other words, the number of malaria cases is lowest in winter and reaches its peak in summer and autumn. This is not due to the parasite itself, but a climatic change is a main reason. In the past years the comprehensive malaria prevention programme has started bearing its fruits. Within the WHO Roll Back Malaria strategies, Turkey has started to implement its national malaria control projects, the meeting held on March 22, 2000, coordinated the country's international cooperation for this purpose. The meeting considered the aim of the project to be introduced into other organizations. In this regards, the target for 2002 is to halve the incidence of malaria as compared to 1999. The middle--and long-term incidence of malaria will be lowered to even smaller figures. The objectives of this project are as follows: to integrate malaria services with primary health care services to prove more effective studies; to develop early diagnosis and treatment systems, to provide better diagnostic services, and to develop mobile diagnostic ones; to make radical treatment and monitoring patients; to conduct regular active case surveillance studies; to conduct regular vector control studies; to monitor the sensitivity of vectors to insecticides and to provide their alternatives; to design malaria control studies for the specialists of districts; to implement educational programmes among the population and attract it in controlling malaria.

Exploring the use of routinely-available, retrospective data to study the association between malaria control scale-up and micro-economic outcomes in Zambia.

PubMed

Comfort, Alison; Leegwater, Anthony; Nakhimovsky, Sharon; Kansembe, Henry; Hamainza, Busiku; Bwalya, Benson; Alilio, Martin; Johns, Ben; Olsho, Lauren

2017-01-04

Country-level evidence on the impact of malaria control on micro-economic outcomes is vital for mobilizing domestic and donor resources for malaria control. Using routinely available survey data could facilitate this investigation in a cost-efficient way. The authors used Malaria Indicator Surveys (MIS) and Living Conditions Monitoring Survey (LCMS) data from 2006 to 2010 for all 72 districts in Zambia to relate malaria control scale-up with household food spending (proxy for household well-being), educational attainment and agricultural production. The authors used two quasi-experimental designs: (1) a generalized propensity score for a continuous treatment variable (defined as coverage from owning insecticide-treated bed nets and/or receipt of indoor residual spraying); and, (2) a district fixed effects model to assess changes in the outcome relative to changes in treatment pre-post scale-up. The unit of analysis was at district level. The authors also conducted simulations post-analysis to assess statistical power. Micro-economic outcomes increased (33% increase in food spending) concurrently with malaria control coverage (62% increase) from 2006 to 2010. Despite using data from all 72 districts, both analytic methods yielded wide confidence intervals that do not conclusively link outcomes and malaria control coverage increases. The authors cannot rule out positive, null or negative effects. The upper bound estimates of the results show that if malaria control coverage increases from 60 to 70%, food spending could increase up to 14%, maize production could increase up to 57%, and years of schooling could increase up to 0.5 years. Simulations indicated that the generalized propensity score model did not have good statistical power. While it is technically possible to use routinely available survey data to relate malaria control scale-up and micro-economic outcomes, it is not clear from this analysis that meaningful results can be obtained when survey data are highly aggregated. Researchers in similar settings should assess the feasibility of disaggregating existing survey data. Additionally, large surveys, such as LCMS and MIS, could incorporate data on both malaria coverage and household expenditures, respectively.

The Anopheles gambiae transcriptome - a turning point for malaria control.

PubMed

Domingos, A; Pinheiro-Silva, R; Couto, J; do Rosário, V; de la Fuente, J

2017-04-01

Mosquitoes are important vectors of several pathogens and thereby contribute to the spread of diseases, with social, economic and public health impacts. Amongst the approximately 450 species of Anopheles, about 60 are recognized as vectors of human malaria, the most important parasitic disease. In Africa, Anopheles gambiae is the main malaria vector mosquito. Current malaria control strategies are largely focused on drugs and vector control measures such as insecticides and bed-nets. Improvement of current, and the development of new, mosquito-targeted malaria control methods rely on a better understanding of mosquito vector biology. An organism's transcriptome is a reflection of its physiological state and transcriptomic analyses of different conditions that are relevant to mosquito vector competence can therefore yield important information. Transcriptomic analyses have contributed significant information on processes such as blood-feeding parasite-vector interaction, insecticide resistance, and tissue- and stage-specific gene regulation, thereby facilitating the path towards the development of new malaria control methods. Here, we discuss the main applications of transcriptomic analyses in An. gambiae that have led to a better understanding of mosquito vector competence. © 2017 The Royal Entomological Society.

Present status of malaria control in Asia

PubMed Central

Dy, F. J.

1954-01-01

The author summarizes the information given by 13 governments—Afghanistan, Burma, Ceylon, China, India, Indonesia, Malaya, Netherlands New Guinea, Philippines, Portuguese India, Sarawak, Thailand, and Viet Nam—on their existing and proposed malaria-control programmes in response to a questionnaire prepared by WHO for discussion at the First Asian Malaria Conference, which was held in Bangkok in September 1953. Although in late 1953 nearly 46.5 million of the 271 million people living in malarious regions were protected against the disease, more than 224 million others were still unprotected. It is noted that residual-insecticide spraying—the basis of most campaigns—has significantly reduced spleen- and parasite-rates; that the minor opposition to spraying initially encountered in some places quickly disappeared as the benefits became apparent; that malaria control has resulted in general improvements in public health and has promoted socio-economic development; that anopheline resistance to the insecticides used has not been observed; that ten governments voiced the need for indoctrination of public officials concerning malaria control; and that there is a trend among governments to make financial provision for long-term malaria-control schemes. PMID:13209318

EMIRA: Ecologic Malaria Reduction for Africa--innovative tools for integrated malaria control.

PubMed

Dambach, Peter; Traoré, Issouf; Becker, Norbert; Kaiser, Achim; Sié, Ali; Sauerborn, Rainer

2014-01-01

Malaria control is based on early treatment of cases and on vector control. The current measures for malaria vector control in Africa are mainly based on long-lasting insecticide treated nets (LLINs) and to a much smaller extent on indoor residual spraying (IRS). A third pillar in the fight against the malaria vector, larval source management (LSM), has virtually not been used in Africa since the ban of DDT in the 1960s. Within the light of recent WHO recommendations for Bacillus thuringiensis israelensis (Bti) use against malaria and other vector species, larval source management could see a revival in the upcoming years. In this project we analyze the ecologic and health impacts as well as the cost effectiveness of larval source management under different larviciding scenarios in a health district in Burkina Faso. The project is designed as prospective intervention study with duration of three years (2013-2015). Its spatial scale includes three arms of interventions and control, comprising a total of 127 villages and the district capital Nouna in the extended HDSS (Health Demographic Surveillance System) of the Kossi province. Baseline data on mosquito abundance, parasitemia in U5 children, and malaria related morbidity and mortality are gathered over the project duration. Besides the outcome on ecologic and health parameters, the economic costs are seized and valued against the achieved health benefits. Risk map based, guided larvicide application might be a possibility to further decrease economic cost of LSM and facilitate its faster incorporation to integrated malaria control programs. Given the limited resources in many malaria endemic countries, it is of utmost importance to relate the costs of novel strategies for malaria prevention to their effect on the burden of the disease. Occurring costs and the impact on the health situation will be made comparable to other, existing intervention strategies, allowing stakeholders and policymakers decision making.

Controlled Human Malaria Infection: Applications, Advances, and Challenges.

PubMed

Stanisic, Danielle I; McCarthy, James S; Good, Michael F

2018-01-01

Controlled human malaria infection (CHMI) entails deliberate infection with malaria parasites either by mosquito bite or by direct injection of sporozoites or parasitized erythrocytes. When required, the resulting blood-stage infection is curtailed by the administration of antimalarial drugs. Inducing a malaria infection via inoculation with infected blood was first used as a treatment (malariotherapy) for neurosyphilis in Europe and the United States in the early 1900s. More recently, CHMI has been applied to the fields of malaria vaccine and drug development, where it is used to evaluate products in well-controlled early-phase proof-of-concept clinical studies, thus facilitating progression of only the most promising candidates for further evaluation in areas where malaria is endemic. Controlled infections have also been used to immunize against malaria infection. Historically, CHMI studies have been restricted by the need for access to insectaries housing infected mosquitoes or suitable malaria-infected individuals. Evaluation of vaccine and drug candidates has been constrained in these studies by the availability of a limited number of Plasmodium falciparum isolates. Recent advances have included cryopreservation of sporozoites, the manufacture of well-characterized and genetically distinct cultured malaria cell banks for blood-stage infection, and the availability of Plasmodium vivax -specific reagents. These advances will help to accelerate malaria vaccine and drug development by making the reagents for CHMI more widely accessible and also enabling a more rigorous evaluation with multiple parasite strains and species. Here we discuss the different applications of CHMI, recent advances in the use of CHMI, and ongoing challenges for consideration. Copyright © 2017 American Society for Microbiology.

Host association and the capacity of sand flies as vectors of lizard malaria in Panama.

PubMed

Kimsey, R B

1992-08-01

In this paper the capacity of sand flies (Lutzomyia) as vectors of parasites that cause malaria in anoles (Anolis limifrons) in the Zona de Canal, Panama was investigated. Inhabiting all study plots, often in local abundance, L. trinidadensis emerged as the principal candidate sand fly vector; the results of surveys did not suggest a likely mosquito vector. Although L. trinidadensis and infected anoles co-inhabited all plots, their abundances seemed unrelated. No evidence that sand flies parasitized anoles was uncovered. As anole activity patterns in daylight reciprocate with those of sand flies and at night anoles seem to avoid locations that sand flies frequent, anoles may evade sand fly bites altogether. Further, these sand flies occurred in close numerical and ecological association with Thecadactylus rapicauda, a reclusive moist forest gecko, often parasitizing these hosts in large numbers. Thus, sand flies lack capacity as vectors of malaria-causing parasites in central Panamanian anoles.

The epidemiology of Plasmodium vivax and Plasmodium falciparum malaria in China, 2004-2012: from intensified control to elimination.

PubMed

Zhang, Qian; Lai, Shengjie; Zheng, Canjun; Zhang, Honglong; Zhou, Sheng; Hu, Wenbiao; Clements, Archie C A; Zhou, Xiao-Nong; Yang, Weizhong; Hay, Simon I; Yu, Hongjie; Li, Zhongjie

2014-11-03

In China, the national malaria elimination programme has been operating since 2010. This study aimed to explore the epidemiological changes in patterns of malaria in China from intensified control to elimination stages. Data on nationwide malaria cases from 2004 to 2012 were extracted from the Chinese national malaria surveillance system. The secular trend, gender and age features, seasonality, and spatial distribution by Plasmodium species were analysed. In total, 238,443 malaria cases were reported, and the proportion of Plasmodium falciparum increased drastically from <10% before 2010 to 55.2% in 2012. From 2004 to 2006, malaria showed a significantly increasing trend and with the highest incidence peak in 2006 (4.6/100,000), while from 2007 onwards, malaria decreased sharply to only 0.18/100,000 in 2012. Males and young age groups became the predominantly affected population. The areas affected by Plasmodium vivax malaria shrunk, while areas affected by P. falciparum malaria expanded from 294 counties in 2004 to 600 counties in 2012. This study demonstrated that malaria has decreased dramatically in the last five years, especially since the Chinese government launched a malaria elimination programme in 2010, and areas with reported falciparum malaria cases have expanded over recent years. These findings suggest that elimination efforts should be improved to meet these changes, so as to achieve the nationwide malaria elimination goal in China in 2020.

Malaria in India: the center for the study of complex malaria in India.

PubMed

Das, Aparup; Anvikar, Anupkumar R; Cator, Lauren J; Dhiman, Ramesh C; Eapen, Alex; Mishra, Neelima; Nagpal, Bhupinder N; Nanda, Nutan; Raghavendra, Kamaraju; Read, Andrew F; Sharma, Surya K; Singh, Om P; Singh, Vineeta; Sinnis, Photini; Srivastava, Harish C; Sullivan, Steven A; Sutton, Patrick L; Thomas, Matthew B; Carlton, Jane M; Valecha, Neena

2012-03-01

Malaria is a major public health problem in India and one which contributes significantly to the overall malaria burden in Southeast Asia. The National Vector Borne Disease Control Program of India reported ∼1.6 million cases and ∼1100 malaria deaths in 2009. Some experts argue that this is a serious underestimation and that the actual number of malaria cases per year is likely between 9 and 50 times greater, with an approximate 13-fold underestimation of malaria-related mortality. The difficulty in making these estimations is further exacerbated by (i) highly variable malaria eco-epidemiological profiles, (ii) the transmission and overlap of multiple Plasmodium species and Anopheles vectors, (iii) increasing antimalarial drug resistance and insecticide resistance, and (iv) the impact of climate change on each of these variables. Simply stated, the burden of malaria in India is complex. Here we describe plans for a Center for the Study of Complex Malaria in India (CSCMi), one of ten International Centers of Excellence in Malaria Research (ICEMRs) located in malarious regions of the world recently funded by the National Institute of Allergy and Infectious Diseases, National Institutes of Health. The CSCMi is a close partnership between Indian and United States scientists, and aims to address major gaps in our understanding of the complexity of malaria in India, including changing patterns of epidemiology, vector biology and control, drug resistance, and parasite genomics. We hope that such a multidisciplinary approach that integrates clinical and field studies with laboratory, molecular, and genomic methods will provide a powerful combination for malaria control and prevention in India. Copyright © 2011 Elsevier B.V. All rights reserved.

Progress towards malaria control targets in relation to national malaria programme funding

PubMed Central

2013-01-01

Background Malaria control has been dramatically scaled up the past decade, mainly thanks to increasing international donor financing since 2003. This study assessed progress up to 2010 towards global malaria impact targets, in relation to Global Fund, other donor and domestic malaria programme financing over 2003 to 2009. Methods Assessments used domestic malaria financing reported by national programmes, and Global Fund/OECD data on donor financing for 90 endemic low- and middle-income countries, WHO estimates of households owning one or more insecticide-treated mosquito net (ITN) for countries in sub-Saharan Africa, and WHO-estimated malaria case incidence and deaths in countries outside sub-Saharan Africa. Results Global Fund and other donor funding is concentrated in a subset of the highest endemic African countries. Outside Africa, donor funding is concentrated in those countries with highest malaria mortality and case incidence rates over the years 2000 to 2003. ITN coverage in 2010 in Africa, and declines in case and death rates per person at risk over 2004 to 2010 outside Africa, were greatest in countries with highest donor funding per person at risk, and smallest in countries with lowest donor malaria funding per person at risk. Outside Africa, all-source malaria programme funding over 2003 to 2009 per case averted ($56-5,749) or per death averted ($58,000-3,900,000) over 2004 to 2010 tended to be lower (more favourable) in countries with higher donor malaria funding per person at risk. Conclusions Increases in malaria programme funding are associated with accelerated progress towards malaria control targets. Associations between programme funding per person at risk and ITN coverage increases and declines in case and death rates suggest opportunities to maximize the impact of donor funding, by strategic re-allocation to countries with highest continued need. PMID:23317000

Malaria Risk Factors in Kaligesing, Purworejo District, Central Java Province, Indonesia: A Case-control Study.

PubMed

Cahyaningrum, Pratiwi; Sulistyawati, Sulistyawati

2018-05-01

Malaria remains a public health concern worldwide, including Indonesia. Purworejo is a district in which endemic of malaria, they have re-setup to entering malaria elimination in 2021. Accordingly, actions must be taken to accelerate and guaranty that the goal will reach based on an understanding of the risk factors for malaria. Thus, we analysed malaria risk factors based on human and housing conditions in Kaligesing, Purworejo, Indonesia. A case-control study was carried out in Kaligesing subdistrict, Purworejo, Indonesia in July to August 2017. A structured questionnaire and checklist were used to collect data from 96 participants, who consisted of 48 controls and 48 cases. Univariate, bivariate, and multivariate analyses were performed. Bivariate analysis found that education level, the presence of a cattle cage within 100 m of the house, not sleeping under a bednet the previous night, and not closing the doors and windows from 6 p.m. to 5 a.m. were significantly ( p ≤0.25) associated with malaria. Of these factors, only not sleeping under a bednet the previous night and not closing the doors and windows from 6 p.m. to 5 a.m. were significantly associated with malaria. The findings of this study demonstrate that potential risk factor for Malaria should be paid of attention all the time, particularly for an area which is targeting Malaria elimination.

Seasonal performance of a malaria rapid diagnosis test at community health clinics in a malaria-hyperendemic region of Burkina Faso

PubMed Central

2012-01-01

Backgound Treatment of confirmed malaria patients with Artemisinin-based Combination Therapy (ACT) at remote areas is the goal of many anti-malaria programs. Introduction of effective and affordable malaria Rapid Diagnosis Test (RDT) in remote areas could be an alternative tool for malaria case management. This study aimed to assess performance of the OptiMAL dipstick for rapid malaria diagnosis in children under five. Methods Malaria symptomatic and asymptomatic children were recruited in a passive manner in two community clinics (CCs). Malaria diagnosis by microscopy and RDT were performed. Performance of the tests was determined. Results RDT showed similar ability (61.2%) to accurately diagnose malaria as microscopy (61.1%). OptiMAL showed a high level of sensitivity and specificity, compared with microscopy, during both transmission seasons (high & low), with a sensitivity of 92.9% vs. 74.9% and a specificity of 77.2% vs. 87.5%. Conclusion By improving the performance of the test through accurate and continuous quality control of the device in the field, OptiMAL could be suitable for use at CCs for the management and control of malaria. PMID:22647557

A sticky situation: the unexpected stability of malaria elimination

PubMed Central

Smith, David L.; Cohen, Justin M.; Chiyaka, Christinah; Johnston, Geoffrey; Gething, Peter W.; Gosling, Roly; Buckee, Caroline O.; Laxminarayan, Ramanan; Hay, Simon I.; Tatem, Andrew J.

2013-01-01

Malaria eradication involves eliminating malaria from every country where transmission occurs. Current theory suggests that the post-elimination challenges of remaining malaria-free by stopping transmission from imported malaria will have onerous operational and financial requirements. Although resurgent malaria has occurred in a majority of countries that tried but failed to eliminate malaria, a review of resurgence in countries that successfully eliminated finds only four such failures out of 50 successful programmes. Data documenting malaria importation and onwards transmission in these countries suggests malaria transmission potential has declined by more than 50-fold (i.e. more than 98%) since before elimination. These outcomes suggest that elimination is a surprisingly stable state. Elimination's ‘stickiness’ must be explained either by eliminating countries starting off qualitatively different from non-eliminating countries or becoming different once elimination was achieved. Countries that successfully eliminated were wealthier and had lower baseline endemicity than those that were unsuccessful, but our analysis shows that those same variables were at best incomplete predictors of the patterns of resurgence. Stability is reinforced by the loss of immunity to disease and by the health system's increasing capacity to control malaria transmission after elimination through routine treatment of cases with antimalarial drugs supplemented by malaria outbreak control. Human travel patterns reinforce these patterns; as malaria recedes, fewer people carry malaria from remote endemic areas to remote areas where transmission potential remains high. Establishment of an international resource with backup capacity to control large outbreaks can make elimination stickier, increase the incentives for countries to eliminate, and ensure steady progress towards global eradication. Although available evidence supports malaria elimination's stickiness at moderate-to-low transmission in areas with well-developed health systems, it is not yet clear if such patterns will hold in all areas. The sticky endpoint changes the projected costs of maintaining elimination and makes it substantially more attractive for countries acting alone, and it makes spatially progressive elimination a sensible strategy for a malaria eradication endgame. PMID:23798693

Equity and adequacy of international donor assistance for global malaria control: an analysis of populations at risk and external funding commitments.

PubMed

Snow, Robert W; Okiro, Emelda A; Gething, Peter W; Atun, Rifat; Hay, Simon I

2010-10-23

Financing for malaria control has increased as part of international commitments to achieve the Millennium Development Goals (MDGs). We aimed to identify the unmet financial needs that would be biologically and economically equitable and would increase the chances of reaching worldwide malaria-control ambitions. Populations at risk of stable Plasmodium falciparum or Plasmodium vivax transmission were calculated for 2007 and 2009 for 93 malaria-endemic countries to measure biological need. National per-person gross domestic product (GDP) was used to define economic need. An analysis of external donor assistance for malaria control was done for the period 2002-09 to compute overall and annualised per-person at-risk-funding commitments. Annualised malaria donor assistance was compared with independent predictions of funding needed to reach international targets of 80% coverage of best practices in case-management and effective disease prevention. Countries were ranked in relation to biological, economic, and unmet needs to examine equity and adequacy of support by 2010. International financing for malaria control has increased by 166% (from $0·73 billion to $1·94 billion) since 2007 and is broadly consistent with biological needs. African countries have become major recipients of external assistance; however, countries where P vivax continues to pose threats to control ambitions are not as well funded. 21 countries have reached adequate assistance to provide a comprehensive suite of interventions by 2009, including 12 countries in Africa. However, this assistance was inadequate for 50 countries representing 61% of the worldwide population at risk of malaria-including ten countries in Africa and five in Asia that coincidentally are some of the poorest countries. Approval of donor funding for malaria control does not correlate with GDP. Funding for malaria control worldwide is 60% lower than the US$4·9 billion needed for comprehensive control in 2010; this includes funding shortfalls for a wide range of countries with different numbers of people at risk and different levels of domestic income. More efficient targeting of financial resources against biological need and national income should create a more equitable investment portfolio that with increased commitments will guarantee sustained financing of control in countries most at risk and least able to support themselves. Wellcome Trust. Copyright © 2010 Elsevier Ltd. All rights reserved.

INSECTICIDE-TREATED BED NETS IN RONDÔNIA, BRAZIL: EVALUATION OF THEIR IMPACT ON MALARIA CONTROL

PubMed Central

Vieira, Gabriel de Deus; Basano, Sergio de Almeida; Katsuragawa, Tony Hiroshi; Camargo, Luís Marcelo Aranha

2014-01-01

Mosquito nets treated with long-lasting insecticide (LLINs), when used in compliance with guidelines of the World Health Organization, may be effective for malaria vector control. In 2012, approximately 150,000 LLINs were installed in nine municipalities in the state of Rondônia. However, no studies have assessed their impact on the reduction of malaria incidence. This study analyzed secondary data of malaria incidence, in order to assess the impact of LLINs on the annual parasite incidence (API). The results showed no statistically significant differences in API one year after LLIN installation when compared to municipalities without LLINs. The adoption of measures for malaria vector control should be associated with epidemiological studies and evaluations of their use and efficiency, with the aim of offering convincing advantages that justify their implementation and limit malaria infection in the Amazon Region. PMID:25351543

Factors Contributing to Urban Malaria Transmission in Sub-Saharan Africa: A Systematic Review

PubMed Central

De Silva, Prathiba M.; Marshall, John M.

2012-01-01

Sub-Saharan Africa suffers by far the greatest malaria burden worldwide and is currently undergoing a profound demographic change, with a growing proportion of its population moving to urban areas. Urbanisation is generally expected to reduce malaria transmission; however the disease still persists in African cities, in some cases at higher levels than in nearby rural areas. Objective. This paper aims to collate and analyse risk factors for urban malaria transmission throughout sub-Saharan Africa and to discuss their implications for control. Methods. A systematic search on malaria and urbanisation was carried out focusing on sub-Saharan Africa. Particular interest was taken in vector breeding sites in urban and periurban areas. Results. A variety of urban vector breeding sites were catalogued, the majority of which were artificial, including urban agriculture, tyre tracks, and ditches. Natural breeding sites varied according to location. Low socioeconomic status was a significant risk factor for malaria, often present in peri-urban areas. A worrying trend was seen in the adaptation of malaria vector species to the urban environment. Urban malaria is highly focused and control programs should reflect this. Conclusion. As urbanisation continues and vector species adapt, continued monitoring and control of urban malaria in sub-Saharan Africa is essential. PMID:23125863

Inhibition of Malaria Infection in Transgenic Anopheline Mosquitoes Lacking Salivary Gland Cells

PubMed Central

Kasashima, Katsumi; Sezutsu, Hideki; Matsuoka, Hiroyuki

2016-01-01

Malaria is an important global public health challenge, and is transmitted by anopheline mosquitoes during blood feeding. Mosquito vector control is one of the most effective methods to control malaria, and population replacement with genetically engineered mosquitoes to block its transmission is expected to become a new vector control strategy. The salivary glands are an effective target tissue for the expression of molecules that kill or inactivate malaria parasites. Moreover, salivary gland cells express a large number of molecules that facilitate blood feeding and parasite transmission to hosts. In the present study, we adapted a functional deficiency system in specific tissues by inducing cell death using the mouse Bcl-2-associated X protein (Bax) to the Asian malaria vector mosquito, Anopheles stephensi. We applied this technique to salivary gland cells, and produced a transgenic strain containing extremely low amounts of saliva. Although probing times for feeding on mice were longer in transgenic mosquitoes than in wild-type mosquitoes, transgenic mosquitoes still successfully ingested blood. Transgenic mosquitoes also exhibited a significant reduction in oocyst formation in the midgut in a rodent malaria model. These results indicate that mosquito saliva plays an important role in malaria infection in the midgut of anopheline mosquitoes. The dysfunction in the salivary glands enabled the inhibition of malaria transmission from hosts to mosquito midguts. Therefore, salivary components have potential in the development of new drugs or genetically engineered mosquitoes for malaria control. PMID:27598328

Malaria survey and malaria control detachments in the South-West Pacific Area in World War 2.

PubMed

Crocker, Denton W

2009-01-01

Malaria among troops in the South-West Pacific Area (SWPA) in World War 2 affected the military effort to the degree that special units were formed to combat it. These malaria survey detachments (MSDs) and malaria control detachments (MCDs) were self-contained and so could move quickly to wherever their services were needed. In SWPA by 25 September 1944 there were 32 MSDs and 65 MCDs. Tables of organization called for 11 enlisted men in MSDs and MCDs, two officers in MSDs and one in MCDs. Detachments served throughout the SWPA. Detailed records of the 31st MSD show that in addition to antimalarial efforts it worked at control of scrub typhus, dengue and venereal disease, at reduction of rat populations and in experimental work involving DDT and schistosomiasis. Specific locations of the 31st MSD were New Guinea (3 sites), Morotai, Leyte, Mindoro, Okinawa and Japan. The detachment served overseas for 21 months. Experience in combating malaria in SWPA in World War 2 points to the need for better and continuous training of both medical and line officers in malaria prevention and control.

Operational research on malaria control and elimination: a review of projects published between 2008 and 2013.

PubMed

Zhou, Shui-sen; Rietveld, Aafje E C; Velarde-Rodriguez, Mar; Ramsay, Andrew R; Zhang, Shao-sen; Zhou, Xiao-nong; Cibulskis, Richard E

2014-12-04

A literature review for operational research on malaria control and elimination was conducted using the term 'malaria' and the definition of operational research (OR). A total of 15 886 articles related to malaria were searched between January 2008 and June 2013. Of these, 582 (3.7%) met the definition of operational research. These OR projects had been carried out in 83 different countries. Most OR studies (77%) were implemented in Africa south of the Sahara. Only 5 (1%) of the OR studies were implemented in countries in the pre-elimination or elimination phase. The vast majority of OR projects (92%) were led by international or local research institutions, while projects led by National Malaria Control Programmes (NMCP) accounted for 7.8%. With regards to the topic under investigation, the largest percentage of papers was related to vector control (25%), followed by epidemiology/transmission (16.5%) and treatment (16.3%). Only 19 (3.8%) of the OR projects were related to malaria surveillance. Strengthening the capacity of NMCPs to conduct operational research and publish its findings, and improving linkages between NMCPs and research institutes may aid progress towards malaria elimination and eventual eradication world-wide.

What Is Threatening the Effectiveness of Insecticide-Treated Bednets? A Case-Control Study of Environmental, Behavioral, and Physical Factors Associated with Prevention Failure.

PubMed

Obala, Andrew A; Mangeni, Judith Nekesa; Platt, Alyssa; Aswa, Daniel; Abel, Lucy; Namae, Jane; Prudhomme O'Meara, Wendy

2015-01-01

Insecticide-treated nets are the cornerstone of global malaria control and have been shown to reduce malaria morbidity by 50-60%. However, some areas are experiencing a resurgence in malaria following successful control. We describe an efficacy decay framework to understand why high malaria burden persists even under high ITN coverage in a community in western Kenya. We enrolled 442 children hospitalized with malaria and paired them with age, time, village and gender-matched controls. We completed comprehensive household and neighborhood assessments including entomological surveillance. The indicators are grouped into five domains in an efficacy decay framework: ITN ownership, compliance, physical integrity, vector susceptibility and facilitating factors. After variable selection, case-control data were analyzed using conditional logistic regression models and mosquito data were analyzed using negative binomial regression. Predictive margins were calculated from logistic regression models. Measures of ITN coverage and physical integrity were not correlated with hospitalized malaria in our study. However, consistent ITN use (Adjusted Odds Ratio (AOR) = 0.23, 95%CI: 0.12-0.43), presence of nearby larval sites (AOR = 1.137, 95%CI: 1.02-1.27), and specific types of crops (AOR (grains) = 0.446, 95%CI: 0.24-0.82) were significantly correlated with malaria amongst children who owned an ITN. The odds of hospitalization for febrile malaria nearly tripled when one other household member had symptomatic malaria infection (AOR-2.76, 95%CI:1.83-4.18). Overall, perfect household adherence could reduce the probability of hospitalization for malaria to less than 30% (95%CI:0.12-0.46) and adjusting environmental factors such as elimination of larval sites and growing grains nearby could reduce the probability of hospitalization for malaria to less than 20% (95%CI:0.04-0.31). Availability of ITNs is not the bottleneck for malaria prevention in this community. Behavior change interventions to improve compliance and environmental management of mosquito breeding habitats may greatly enhance ITN efficacy. A better understanding of the relationship between agriculture and mosquito survival and feeding success is needed.

Safety and Allele-Specific Immunogenicity of a Malaria Vaccine in Malian Adults: Results of a Phase I Randomized Trial

PubMed Central

Thera, Mahamadou A; Doumbo, Ogobara K; Coulibaly, Drissa; Diallo, Dapa A; Sagara, Issaka; Dicko, Alassane; Diemert, David J; Heppner, D. Gray; Stewart, V. Ann; Angov, Evelina; Soisson, Lorraine; Leach, Amanda; Tucker, Kathryn; Lyke, Kirsten E; Plowe, Christopher V

2006-01-01

Objectives: The objectives were to evaluate the safety, reactogenicity, and allele-specific immunogenicity of the blood-stage malaria vaccine FMP1/AS02A in adults exposed to seasonal malaria and the impact of natural infection on vaccine-induced antibody levels. Design: We conducted a randomized, double-blind, controlled phase I clinical trial. Setting: Bandiagara, Mali, West Africa, is a rural town with intense seasonal transmission of Plasmodium falciparum malaria. Participants: Forty healthy, malaria-experienced Malian adults aged 18–55 y were enrolled. Interventions: The FMP1/AS02A malaria vaccine is a 42-kDa recombinant protein based on the carboxy-terminal end of merozoite surface protein-1 (MSP-142) from the 3D7 clone of P. falciparum, adjuvanted with AS02A. The control vaccine was a killed rabies virus vaccine (Imovax). Participants were randomized to receive either FMP1/AS02A or rabies vaccine at 0, 1, and 2 mo and were followed for 1 y. Outcome Measures: Solicited and unsolicited adverse events and allele-specific antibody responses to recombinant MSP-142 and its subunits derived from P. falciparum strains homologous and heterologous to the 3D7 vaccine strain were measured. Results: Transient local pain and swelling were more common in the malaria vaccine group than in the control group (11/20 versus 3/20 and 10/20 versus 6/20, respectively). MSP-142 antibody levels rose during the malaria transmission season in the control group, but were significantly higher in malaria vaccine recipients after the second immunization and remained higher after the third immunization relative both to baseline and to the control group. Immunization with the malaria vaccine was followed by significant increases in antibodies recognizing three diverse MSP-142 alleles and their subunits. Conclusions: FMP1/AS02A was well tolerated and highly immunogenic in adults exposed to intense seasonal malaria transmission and elicited immune responses to genetically diverse parasite clones. Anti-MSP-142 antibody levels followed a seasonal pattern that was significantly augmented and prolonged by the malaria vaccine. PMID:17124530

[Investigation on awareness rates of malaria prevention knowledge among residents and students in Huai'an District, Huai'an City].

PubMed

Su-Min, Ren; Zhao-Wu, Tang

2016-05-24

To understand the awareness status on malaria control knowledge of residents, primary and middle school students in Huai'an District, Huai'an City, so as to provide the evidences for promoting the malaria elimination process in this district. Three towns in Huai'an District were selected randomly, and one village, one primary school and one junior middle school in each town were chosen as the investigation sites. The residents over 18 years old, the primary school students in Grade 4 to 6, and the junior middle students in the investigation sites were investigated by questionnaires to understand their awareness status on knowledge of malaria control. Totally 305 residents and 618 students were investigated. The awareness rate of students was 89.97%, and the rates of the junior middle school students and primary school students were 85.94% and 94.10%, respectively, the difference between them was statistically significant ( P ＜0.01). The awareness rate of the residents was 80.98%, which was lower than that of the students ( P ＜0.05). For the students, the awareness rate on "precaution of malaria" (96.74%) was the highest, while that on "drug of malaria" (68.93%) was the lowest. For the residents, the rate on "transmission route of malaria" (95.08%) was the highest, that on "4·26 is Malaria Day" (64.26%) was the lowest. Expect the items of "transmission route of malaria" and "precaution of malaria" (both P ＞0.05), the differences of the awareness rates on all the other items between the students and residents were statistically significant (all P ＜0.01). Although the awareness rates of malaria control knowledge in the population of Huai'an District, Huai'an City have achieved the goal of the relevant requirement, the health education on malaria control still should be strengthened, especially for the primary students, female residents and exported labor service personnel.

Review of research on malaria*

PubMed Central

Lepes, T.

1974-01-01

This review of progress in malaria research over the periods 1951-1970 and 1970-1973 indicates the results so far achieved in research on the parasite, on the immune response of the host, and on the vector; refers to the means of controlling or eradicating malaria that have been developed in recent years; and outlines the present status of the malaria control and eradication programme. Although impressive results have already been achieved in malaria research, more systematization and concentration of efforts are required if real breakthroughs are to be made. The experience gained in this respect is discussed. PMID:4613499

The Malaria Transition on the Arabian Peninsula: Progress toward a Malaria-Free Region between 1960–2010

PubMed Central

Snow, Robert W.; Amratia, Punam; Zamani, Ghasem; Mundia, Clara W.; Noor, Abdisalan M.; Memish, Ziad A.; Al Zahrani, Mohammad H.; Al Jasari, Adel; Fikri, Mahmoud; Atta, Hoda

2014-01-01

The transmission of malaria across the Arabian Peninsula is governed by the diversity of dominant vectors and extreme aridity. It is likely that where malaria transmission was historically possible it was intense and led to a high disease burden. Here, we review the speed of elimination, approaches taken, define the shrinking map of risk since 1960 and discuss the threats posed to a malaria-free Arabian Peninsula using the archive material, case data and published works. From as early as the 1940s, attempts were made to eliminate malaria on the peninsula but were met with varying degrees of success through to the 1970s; however, these did result in a shrinking of the margins of malaria transmission across the peninsula. Epidemics in the 1990s galvanised national malaria control programmes to reinvigorate control efforts. Before the launch of the recent global ambition for malaria eradication, countries on the Arabian Peninsula launched a collaborative malaria-free initiative in 2005. This initiative led a further shrinking of the malaria risk map and today locally acquired clinical cases of malaria are reported only in Saudi Arabia and Yemen, with the latter contributing to over 98% of the clinical burden. PMID:23548086

Blantyre Malaria Project Epilepsy Study (BMPES) of neurological outcomes in retinopathy-positive paediatric cerebral malaria survivors: a prospective cohort study.

PubMed

Birbeck, Gretchen L; Molyneux, Malcolm E; Kaplan, Peter W; Seydel, Karl B; Chimalizeni, Yamikani F; Kawaza, Kondwani; Taylor, Terrie E

2010-12-01

Cerebral malaria, a disorder characterised by coma, parasitaemia, and no other evident cause of coma, is challenging to diagnose definitively in endemic regions that have high rates of asymptomatic parasitaemia and limited neurodiagnostic facilities. A recently described malaria retinopathy improves diagnostic specificity. We aimed to establish whether retinopathy-positive cerebral malaria is a risk factor for epilepsy or other neurodisabilities. Between 2005 and 2007, we did a prospective cohort study of survivors of cerebral malaria with malaria retinopathy in Blantyre, Malawi. Children with cerebral malaria were identified at the time of their index admission and age-matched to concurrently admitted children without coma or nervous system infection. Initially matching of cases to controls was 1:1 but, in 2006, enrolment criteria for cerebral malaria survivors were revised to limit inclusion to children with cerebral malaria and retinopathy on the basis of indirect ophthalmoscopic examination; matching was then changed to 1:2 and the revised inclusion criteria were applied retrospectively for children enrolled previously. Clinical assessments at discharge and standardised nurse-led follow-up every 3 months thereafter were done to identify children with new seizure disorders or other neurodisabilities. A Kaplan-Meier survival analysis was done for incident epilepsy. 132 children with retinopathy-positive cerebral malaria and 264 age-matched, non-comatose controls were followed up for a median of 495 days (IQR 195-819). 12 of 132 cerebral malaria survivors developed epilepsy versus none of 264 controls (odds ratio [OR] undefined; p<0·0001). 28 of 121 cerebral malaria survivors developed new neurodisabilities, characterised by gross motor, sensory, or language deficits, compared with two of 253 controls (OR 37·8, 95% CI 8·8-161·8; p<0·0001). The risk factors for epilepsy in children with cerebral malaria were a higher maximum temperature (39·4°C [SD 1·2] vs 38·5°C [1·1]; p=0·01) and acute seizures (11/12 vs 76/120; OR 6·37, 95% CI 1·02-141·2), and male sex was a risk factor for new neurodisabilities (20/28 vs 38/93; OR 3·62, 1·44-9·06). Almost a third of retinopathy-positive cerebral malaria survivors developed epilepsy or other neurobehavioural sequelae. Neuroprotective clinical trials aimed at managing hyperpyrexia and optimising seizure control are warranted. US National Institutes of Health and Wellcome Trust. Copyright © 2010 Elsevier Ltd. All rights reserved.

Plasmodium vivax Malaria in Cambodia

PubMed Central

Siv, Sovannaroth; Roca-Feltrer, Arantxa; Vinjamuri, Seshu Babu; Bouth, Denis Mey; Lek, Dysoley; Rashid, Mohammad Abdur; By, Ngau Peng; Popovici, Jean; Huy, Rekol; Menard, Didier

2016-01-01

The Cambodian National Strategic Plan for Elimination of Malaria aims to move step by step toward elimination of malaria across Cambodia with an initial focus on Plasmodium falciparum malaria before achieving elimination of all forms of malaria, including Plasmodium vivax in 2025. The emergence of artemisinin-resistant P. falciparum in western Cambodia over the last decade has drawn global attention to support the ultimate goal of P. falciparum elimination, whereas the control of P. vivax lags much behind, making the 2025 target gradually less achievable unless greater attention is given to P. vivax elimination in the country. The following review presents in detail the past and current situation regarding P. vivax malaria, activities of the National Malaria Control Program, and interventional measures applied. Constraints and obstacles that can jeopardize our efforts to eliminate this parasite species are discussed. PMID:27708187

The economic burden of malaria.

PubMed

Gallup, J L; Sachs, J D

2001-01-01

Malaria and poverty are intimately connected. Controlling for factors such as tropical location, colonial history, and geographical isolation, countries with intensive malaria had income levels in 1995 of only 33% that of countries without malaria, whether or not the countries were in Africa. The high levels of malaria in poor countries are not mainly a consequence of poverty. Malaria is geographically specific. The ecological conditions that support the more efficient malaria mosquito vectors primarily determine the distribution and intensity of the disease. Intensive efforts to eliminate malaria in the most severely affected tropical countries have been largely ineffective. Countries that have eliminated malaria in the past half century have all been either subtropical or islands. These countries' economic growth in the 5 years after eliminating malaria has usually been substantially higher than growth in the neighboring countries. Cross-country regressions for the 1965-1990 period confirm the relationship between malaria and economic growth. Taking into account initial poverty, economic policy, tropical location, and life expectancy, among other factors, countries with intensive malaria grew 1.3% less per person per year, and a 10% reduction in malaria was associated with 0.3% higher growth. Controlling for many other tropical diseases does not change the correlation of malaria with economic growth, and these diseases are not themselves significantly negatively correlated with economic growth. A second independent measure of malaria has a slightly higher correlation with economic growth in the 1980-1996 period. We speculate about the mechanisms that could cause malaria to have such a large impact on the economy, such as foreign investment and economic networks within the country.

Prospects for malaria elimination in non-Amazonian regions of Latin America

PubMed Central

Herrera, Sócrates; Quiñones, Martha Lucia; Quintero, Juan Pablo; Corredor, Vladimir; Fuller, Douglas O.; Mateus, Julio Cesar; Calzada, Jose E.; Gutierrez, Juan B.; Llanos, Alejandro; Soto, Edison; Menendez, Clara; Wu, Yimin; Alonso, Pedro; Carrasquilla, Gabriel; Galinski, Mary; Beier, John C.; Arevalo-Herrera, Myriam

2011-01-01

Latin America contributes 1 to 1.2 million clinical malaria cases to the global malaria burden of about 300 million per year. In 21 malaria endemic countries, the population at risk in this region represents less than 10% of the total population exposed worldwide. Factors such as rapid deforestation, inadequate agricultural practices, climate change, political instability, and both increasing parasite drug resistance and vector resistance to insecticides contribute to malaria transmission. Recently, several malaria endemic countries have experienced a significant reduction in numbers of malaria cases. This is most likely due to actions taken by National Malaria Control Programs (NMCP) with the support from international funding agencies. We describe here the research strategies and activities to be undertaken by the Centro Latino Americano de Investigación en Malaria (CLAIM), a new research center established for the non-Amazonian region of Latin America by the National Institute of Allergy and Infectious Diseases (NIAID). Throughout a network of countries in the region, initially including Colombia, Guatemala, Panama, and Peru, CLAIM will address major gaps in our understanding of changing malaria epidemiology, vector biology and control, and clinical malaria mainly due to Plasmodium vivax. In close partnership with NMCPs, CLAIM seeks to conduct research on how and why malaria is decreasing in many countries of the region as a basis for developing and implementing new strategies that will accelerate malaria elimination. PMID:21781953

Malaria in Brazil: what happens outside the Amazonian endemic region.

PubMed

de Pina-Costa, Anielle; Brasil, Patrícia; Di Santi, Sílvia Maria; de Araujo, Mariana Pereira; Suárez-Mutis, Martha Cecilia; Santelli, Ana Carolina Faria e Silva; Oliveira-Ferreira, Joseli; Lourenço-de-Oliveira, Ricardo; Daniel-Ribeiro, Cláudio Tadeu

2014-08-01

Brazil, a country of continental proportions, presents three profiles of malaria transmission. The first and most important numerically, occurs inside the Amazon. The Amazon accounts for approximately 60% of the nation's territory and approximately 13% of the Brazilian population. This region hosts 99.5% of the nation's malaria cases, which are predominantly caused by Plasmodium vivax (i.e., 82% of cases in 2013). The second involves imported malaria, which corresponds to malaria cases acquired outside the region where the individuals live or the diagnosis was made. These cases are imported from endemic regions of Brazil (i.e., the Amazon) or from other countries in South and Central America, Africa and Asia. Imported malaria comprised 89% of the cases found outside the area of active transmission in Brazil in 2013. These cases highlight an important question with respect to both therapeutic and epidemiological issues because patients, especially those with falciparum malaria, arriving in a region where the health professionals may not have experience with the clinical manifestations of malaria and its diagnosis could suffer dramatic consequences associated with a potential delay in treatment. Additionally, because the Anopheles vectors exist in most of the country, even a single case of malaria, if not diagnosed and treated immediately, may result in introduced cases, causing outbreaks and even introducing or reintroducing the disease to a non-endemic, receptive region. Cases introduced outside the Amazon usually occur in areas in which malaria was formerly endemic and are transmitted by competent vectors belonging to the subgenus Nyssorhynchus (i.e., Anopheles darlingi, Anopheles aquasalis and species of the Albitarsis complex). The third type of transmission accounts for only 0.05% of all cases and is caused by autochthonous malaria in the Atlantic Forest, located primarily along the southeastern Atlantic Coast. They are caused by parasites that seem to be (or to be very close to) P. vivax and, in a less extent, by Plasmodium malariae and it is transmitted by the bromeliad mosquito Anopheles (Kerteszia) cruzii. This paper deals mainly with the two profiles of malaria found outside the Amazon: the imported and ensuing introduced cases and the autochthonous cases. We also provide an update regarding the situation in Brazil and the Brazilian endemic Amazon.

Malaria in Brazil: what happens outside the Amazonian endemic region

PubMed Central

de Pina-Costa, Anielle; Brasil, Patrícia; Santi, Sílvia Maria Di; de Araujo, Mariana Pereira; Suárez-Mutis, Martha Cecilia; Santelli, Ana Carolina Faria e Silva; Oliveira-Ferreira, Joseli; Lourenço-de-Oliveira, Ricardo; Daniel-Ribeiro, Cláudio Tadeu

2014-01-01

Brazil, a country of continental proportions, presents three profiles of malaria transmission. The first and most important numerically, occurs inside the Amazon. The Amazon accounts for approximately 60% of the nation’s territory and approximately 13% of the Brazilian population. This region hosts 99.5% of the nation’s malaria cases, which are predominantly caused by Plasmodium vivax (i.e., 82% of cases in 2013). The second involves imported malaria, which corresponds to malaria cases acquired outside the region where the individuals live or the diagnosis was made. These cases are imported from endemic regions of Brazil (i.e., the Amazon) or from other countries in South and Central America, Africa and Asia. Imported malaria comprised 89% of the cases found outside the area of active transmission in Brazil in 2013. These cases highlight an important question with respect to both therapeutic and epidemiological issues because patients, especially those with falciparum malaria, arriving in a region where the health professionals may not have experience with the clinical manifestations of malaria and its diagnosis could suffer dramatic consequences associated with a potential delay in treatment. Additionally, because the Anopheles vectors exist in most of the country, even a single case of malaria, if not diagnosed and treated immediately, may result in introduced cases, causing outbreaks and even introducing or reintroducing the disease to a non-endemic, receptive region. Cases introduced outside the Amazon usually occur in areas in which malaria was formerly endemic and are transmitted by competent vectors belonging to the subgenus Nyssorhynchus (i.e., Anopheles darlingi, Anopheles aquasalis and species of the Albitarsis complex). The third type of transmission accounts for only 0.05% of all cases and is caused by autochthonous malaria in the Atlantic Forest, located primarily along the southeastern Atlantic Coast. They are caused by parasites that seem to be (or to be very close to) P. vivax and, in a less extent, by Plasmodium malariae and it is transmitted by the bromeliad mosquito Anopheles (Kerteszia) cruzii. This paper deals mainly with the two profiles of malaria found outside the Amazon: the imported and ensuing introduced cases and the autochthonous cases. We also provide an update regarding the situation in Brazil and the Brazilian endemic Amazon. PMID:25185003

Dynamical Mapping of Anopheles darlingi Densities in a Residual Malaria Transmission Area of French Guiana by Using Remote Sensing and Meteorological Data

PubMed Central

Adde, Antoine; Roux, Emmanuel; Mangeas, Morgan; Dessay, Nadine; Nacher, Mathieu; Dusfour, Isabelle; Girod, Romain; Briolant, Sébastien

2016-01-01

Local variation in the density of Anopheles mosquitoes and the risk of exposure to bites are essential to explain the spatial and temporal heterogeneities in the transmission of malaria. Vector distribution is driven by environmental factors. Based on variables derived from satellite imagery and meteorological observations, this study aimed to dynamically model and map the densities of Anopheles darlingi in the municipality of Saint-Georges de l’Oyapock (French Guiana). Longitudinal sampling sessions of An. darlingi densities were conducted between September 2012 and October 2014. Landscape and meteorological data were collected and processed to extract a panel of variables that were potentially related to An. darlingi ecology. Based on these data, a robust methodology was formed to estimate a statistical predictive model of the spatial-temporal variations in the densities of An. darlingi in Saint-Georges de l’Oyapock. The final cross-validated model integrated two landscape variables—dense forest surface and built surface—together with four meteorological variables related to rainfall, evapotranspiration, and the minimal and maximal temperatures. Extrapolation of the model allowed the generation of predictive weekly maps of An. darlingi densities at a resolution of 10-m. Our results supported the use of satellite imagery and meteorological data to predict malaria vector densities. Such fine-scale modeling approach might be a useful tool for health authorities to plan control strategies and social communication in a cost-effective, targeted, and timely manner. PMID:27749938

Dynamical Mapping of Anopheles darlingi Densities in a Residual Malaria Transmission Area of French Guiana by Using Remote Sensing and Meteorological Data.

PubMed

Adde, Antoine; Roux, Emmanuel; Mangeas, Morgan; Dessay, Nadine; Nacher, Mathieu; Dusfour, Isabelle; Girod, Romain; Briolant, Sébastien

2016-01-01

Local variation in the density of Anopheles mosquitoes and the risk of exposure to bites are essential to explain the spatial and temporal heterogeneities in the transmission of malaria. Vector distribution is driven by environmental factors. Based on variables derived from satellite imagery and meteorological observations, this study aimed to dynamically model and map the densities of Anopheles darlingi in the municipality of Saint-Georges de l'Oyapock (French Guiana). Longitudinal sampling sessions of An. darlingi densities were conducted between September 2012 and October 2014. Landscape and meteorological data were collected and processed to extract a panel of variables that were potentially related to An. darlingi ecology. Based on these data, a robust methodology was formed to estimate a statistical predictive model of the spatial-temporal variations in the densities of An. darlingi in Saint-Georges de l'Oyapock. The final cross-validated model integrated two landscape variables-dense forest surface and built surface-together with four meteorological variables related to rainfall, evapotranspiration, and the minimal and maximal temperatures. Extrapolation of the model allowed the generation of predictive weekly maps of An. darlingi densities at a resolution of 10-m. Our results supported the use of satellite imagery and meteorological data to predict malaria vector densities. Such fine-scale modeling approach might be a useful tool for health authorities to plan control strategies and social communication in a cost-effective, targeted, and timely manner.

Consolidating strategic planning and operational frameworks for integrated vector management in Eritrea.

PubMed

Chanda, Emmanuel; Ameneshewa, Birkinesh; Mihreteab, Selam; Berhane, Araia; Zehaie, Assefash; Ghebrat, Yohannes; Usman, Abdulmumini

2015-12-02

Contemporary malaria vector control relies on the use of insecticide-based, indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs). However, malaria-endemic countries, including Eritrea, have struggled to effectively deploy these tools due technical and operational challenges, including the selection of insecticide resistance in malaria vectors. This manuscript outlines the processes undertaken in consolidating strategic planning and operational frameworks for vector control to expedite malaria elimination in Eritrea. The effort to strengthen strategic frameworks for vector control in Eritrea was the 'case' for this study. The integrated vector management (IVM) strategy was developed in 2010 but was not well executed, resulting in a rise in malaria transmission, prompting a process to redefine and relaunch the IVM strategy with integration of other vector borne diseases (VBDs) as the focus. The information sources for this study included all available data and accessible archived documentary records on malaria vector control in Eritrea. Structured literature searches of published, peer-reviewed sources using online, scientific, bibliographic databases, Google Scholar, PubMed and WHO, and a combination of search terms were utilized to gather data. The literature was reviewed and adapted to the local context and translated into the consolidated strategic framework. In Eritrea, communities are grappling with the challenge of VBDs posing public health concerns, including malaria. The global fund financed the scale-up of IRS and LLIN programmes in 2014. Eritrea is transitioning towards malaria elimination and strategic frameworks for vector control have been consolidated by: developing an integrated vector management (IVM) strategy (2015-2019); updating IRS and larval source management (LSM) guidelines; developing training manuals for IRS and LSM; training of national staff in malaria entomology and vector control, including insecticide resistance monitoring techniques; initiating the global plan for insecticide resistance management; conducting needs' assessments and developing standard operating procedure for insectaries; developing a guidance document on malaria vector control based on eco-epidemiological strata, a vector surveillance plan and harmonized mapping, data collection and reporting tools. Eritrea has successfully consolidated strategic frameworks for vector control. Rational decision-making remains critical to ensure that the interventions are effective and their choice is evidence-based, and to optimize the use of resources for vector control. Implementation of effective IVM requires proper collaboration and coordination, consistent technical and financial capacity and support to offer greater benefits.

The use of schools for malaria surveillance and programme evaluation in Africa

PubMed Central

Brooker, Simon; Kolaczinski, Jan H; Gitonga, Carol W; Noor, Abdisalan M; Snow, Robert W

2009-01-01

Effective malaria control requires information on both the geographical distribution of malaria risk and the effectiveness of malaria interventions. The current standard for estimating malaria infection and impact indicators are household cluster surveys, but their complexity and expense preclude frequent and decentralized monitoring. This paper reviews the historical experience and current rationale for the use of schools and school children as a complementary, inexpensive framework for planning, monitoring and evaluating malaria control in Africa. Consideration is given to (i) the selection of schools; (ii) diagnosis of infection in schools; (iii) the representativeness of schools as a proxy of the communities they serve; and (iv) the increasing need to evaluate interventions delivered through schools. Finally, areas requiring further investigation are highlighted. PMID:19840372

[Cultural domains pertaining to malaria: an approach to non-institutional knowledge].

PubMed

Fernández-Niño, Julián A; Idrovo, Álvaro J; Giraldo-Gartner, Vanesa; Molina-León, Helvert F

2014-01-01

Malaria control policies have not fully achieved the expected results due to little consideration of cultural aspects, among other factors. To explore the cultural domains pertaining to this disease in an endemic Colombian population, in order to both design and implement effective action plans. A convenience sampling was conducted to select inhabitants from 12 villages in Tierralta, Córdoba. In order to generate free-lists, participants were asked about their communities' health problems, causes of malaria, control measures and those responsible for malaria control. Smith's indexes were calculated for each item answered. Between 30 and 38 individuals per village participated in the study (N=401). The mean age was 40.24 years (standard deviation (SD)=14.22) and women were 45.39% of the total. Participants recognized malaria and respiratory infections as the primary health problems in the community (median Smith's indexes: 0.83 and 0.63, respectively). A lack of environmental interventions was identified as the main determinant of malaria (median Smith's index: 0.65). Finally, the health care center (median Smith's index: 0.71) and health professionals (median Smith's index: 0.52) were identified as those most responsible for malaria control. The design of programs to reduce the impact of malaria requires developing interventions or initiatives that are adapted to the community's needs, demands and available resources. Free-listing is proposed as an effective tool to collect information about cultural domains related to health.

Changing strategy in malaria control

PubMed Central

Pampana, E. J.

1954-01-01

Residual-insecticide spraying methods may lead to the eradication of malaria from a country or from an area of it, and therefore to the possibility that the spraying campaign may eventually be discontinued. This is the final target to be aimed at in planning national malaria-control campaigns. As it is now known that some anopheline vector species may develop resistance to insecticides, a plea is made that control programmes should be planned to cover such large areas and with such criteria of efficiency as to eradicate malaria and to enable the campaign to be discontinued before resistance may have developed. PMID:13209311

Sustaining control: lessons from the Lubombo spatial development initiative in southern Africa.

PubMed

Maharaj, Rajendra; Moonasar, Devanand; Baltazar, Candrinho; Kunene, Simon; Morris, Natashia

2016-08-12

The Lubombo Spatial Development Initiative (LSDI) was a tri-country project between South Africa, Swaziland and Mozambique with the aim of accelerating socio-economic development in the region. The malaria component of the project was introduced to decrease the transmission of malaria in the region. This goal was met but with termination of this project resulted in an upsurge of malaria cases in the sub-region mainly as a result of migration from high transmission areas to low transmission ones. The movement of people across borders in southern Africa remains a challenge in sustaining malaria control and elimination. Malaria case data for Swaziland and South Africa were obtained from their respective national Malaria Information Systems. Data for Mozambique was obtained from the Mozambican Ministry of Health. Data obtained during the course of the LSDI project was compared to the case data post the termination of the LSDI. The 12-year period of the LSDI showed a substantial decrease in disease burden amongst the three countries involved when compared to the baseline year of 2000. The decrease in malaria cases was 99 % in South Africa and 98 % in Swaziland. Malaria prevalence in Mozambique decreased by 85 % over the same period. However, after the LSDI ended, between 2012 and 2014, there was an upward trend in case data that was counter to the goal of elimination. South Africa and Swaziland benefitted from the LSDI and were able to sustain malaria control and progress to the stage of elimination. Mozambique could not sustain the gains made during the LSDI and case numbers increased. Technical and financial resources are key challenges for malaria control and elimination interventions.

Increasing incidence of malaria in children despite insecticide-treated bed nets and prompt anti-malarial therapy in Tororo, Uganda

PubMed Central

2012-01-01

Background The burden of malaria has decreased in parts of Africa following the scaling up of control interventions. However, similar data are limited from high transmission settings. Methods A cohort of 100 children, aged six weeks to 10 months of age, were enrolled in an area of high malaria transmission intensity and followed through 48 months of age. Children were given a long-lasting insecticide-treated bed net (LLIN) at enrolment and received all care, including monthly blood smears and treatment with artemisinin-based combination therapy (ACT) for uncomplicated malaria, at a dedicated clinic. The incidence of malaria was estimated by passive surveillance and associations between malaria incidence and age, calendar time and season were measured using generalized estimating equations. Results Reported compliance with LLINs was 98% based on monthly routine evaluations. A total of 1,633 episodes of malaria were observed, with a median incidence of 5.3 per person-year (PPY). There were only six cases of complicated malaria, all single convulsions. Malaria incidence peaked at 6.5 PPY at 23 months of age before declining to 3.5 PPY at 48 months. After adjusting for age and season, the risk of malaria increased by 52% from 2008 to 2011 (RR 1.52, 95% CI 1.10-2.09). Asymptomatic parasitaemia was uncommon (monthly prevalence <10%) and rarely observed prior to 24 months of age. Conclusions In Tororo, despite provision of LLINs and prompt treatment with ACT, the incidence of malaria is very high and appears to be rising. Additional malaria control interventions in high transmission settings are likely needed. Trial registration Current Controlled Trials Identifier NCT00527800 PMID:23273022

Clinical signs and symptoms cannot reliably predict Plasmodium falciparum malaria infection in pregnant women living in an area of high seasonal transmission.

PubMed

Tahita, Marc C; Tinto, Halidou; Menten, Joris; Ouedraogo, Jean-Bosco; Guiguemde, Robert T; van Geertruyden, Jean Pierre; Erhart, Annette; D'Alessandro, Umberto

2013-12-27

Malaria in pregnancy is a major public health problem in endemic countries. Though the signs and symptoms of malaria among pregnant women have been already described, clinical presentation may vary according to intensity of transmission and local perceptions. Therefore, determining common signs and symptoms among pregnant women with a malaria infection may be extremely useful to identify those in need of further investigation by rapid diagnostic test or microscopy. Six hundred pregnant women attending the maternity clinic of Nanoro District Hospital, Burkina Faso were recruited, 200 with suspected clinical malaria and 400 as controls. Cases were matched with controls by gestational age and parity. Signs and symptoms were collected and a blood sample taken for rapid diagnostic test, microscopy and haemoglobin measurement. A multivariate model was used to assess the predictive value of signs and symptoms for malaria infection. The overall prevalence of malaria was 42.6% (256/600) while anaemia was found in 60.8% (365/600) of the women. Nearly half (49%) of the cases and 39.5% of the controls had a malaria infection (p = 0.03). The most common signs and symptoms among the cases were fever (36%,72/200), history of fever (29%,58/200) and headache (52%,104/200). The positive predictive value for fever was 53% (95% CI:41-64), history of fever 58% (95% CI:37-63) and headache 51% (95% CI:41-61). Signs and symptoms suggestive of malaria are frequent among pregnant women living in areas of intense transmission. Common malaria symptoms are not strong predictors of infection. For a better management of malaria in pregnancy, active screening to detect and treat malaria infection early should be performed on all pregnant women attending a health facility.

Prevalence of asymptomatic malaria infection and use of different malaria control measures among primary school children in Morogoro Municipality, Tanzania.

PubMed

Nzobo, Baraka J; Ngasala, Billy E; Kihamia, Charles M

2015-12-02

Malaria is a public health problem in Tanzania affecting all age groups. It is known that school children are the age group most commonly infected with malaria parasites. Their infections are usually asymptomatic, go unnoticed and thus never get treated, result in anaemia, reduced ability to concentrate and learn in school and if fallen sick may lead to school absenteeism. Effective malaria control requires frequent evaluation of effectiveness of different malaria interventions. A cross-sectional study design involving 317 out of 350 school children aged 6-13 years from five primary schools within municipality was conducted. Multistage cluster sampling and simple random sampling methods were used to obtain primary school and study participants, respectively. Finger-prick blood samples were collected for Plasmodium parasite detection by malaria rapid diagnostic test (mRDT) and haemoglobin level assessment by Easy Touch(®) GHb system machine. A questionnaire was administered to assess use of insecticide-treated nets (ITNs) and anti-malarial drugs. The prevalence of asymptomatic malaria was 5.4 % (95 % CI 3.3-8.6 %) and anaemia was 10.1 % (95 % CI 7.2-13.9 %). School children aged 6-9 years were more affected by malaria than those aged 10-13 years. The proportion of ITNs used was 90.6 % (95 % CI 86.3-93.9 %) while that of artemisinin combination therapy (ACT) was 71.9 % (95 % CI 66.2-77.1 %). Findings show existence of asymptomatic malaria and walking anaemia among primary school children in Morogoro municipality. The majority of school children reported use of ITNs and ACT for malaria control. These findings provide a rationale for using schools and school children to assess effectiveness of malaria interventions.

Seasonal prevalence of malaria in West Sumba district, Indonesia

PubMed Central

Syafruddin, Din; Krisin; Asih, Puji; Sekartuti; Dewi, Rita M; Coutrier, Farah; Rozy, Ismail E; Susanti, Augustina I; Elyazar, Iqbal RF; Sutamihardja, Awalludin; Rahmat, Agus; Kinzer, Michael; Rogers, William O

2009-01-01

Background Accurate information about the burden of malaria infection at the district or provincial level is required both to plan and assess local malaria control efforts. Although many studies of malaria epidemiology, immunology, and drug resistance have been conducted at many sites in Indonesia, there is little published literature describing malaria prevalence at the district, provincial, or national level. Methods Two stage cluster sampling malaria prevalence surveys were conducted in the wet season and dry season across West Sumba, Nusa Tenggara Province, Indonesia. Results Eight thousand eight hundred seventy samples were collected from 45 sub-villages in the surveys. The overall prevalence of malaria infection in the West Sumba District was 6.83% (95% CI, 4.40, 9.26) in the wet season and 4.95% (95% CI, 3.01, 6.90) in the dry. In the wet season Plasmodium falciparum accounted for 70% of infections; in the dry season P. falciparum and Plasmodium vivax were present in equal proportion. Malaria prevalence varied substantially across the district; prevalences in individual sub-villages ranged from 0–34%. The greatest malaria prevalence was in children and teenagers; the geometric mean parasitaemia in infected individuals decreased with age. Malaria infection was clearly associated with decreased haemoglobin concentration in children under 10 years of age, but it is not clear whether this association is causal. Conclusion Malaria is hypoendemic to mesoendemic in West Sumba, Indonesia. The age distribution of parasitaemia suggests that transmission has been stable enough to induce some clinical immunity. These prevalence data will aid the design of future malaria control efforts and will serve as a baseline against which the results of current and future control efforts can be assessed. PMID:19134197

Implementation of Home based management of malaria in children reduces the work load for peripheral health facilities in a rural district of Burkina Faso.

PubMed

Tiono, Alfred B; Kaboré, Youssouf; Traoré, Abdoulaye; Convelbo, Nathalie; Pagnoni, Franco; Sirima, Sodiomon B

2008-10-03

Home Management of Malaria (HMM) is one of the key strategies to reduce the burden of malaria for vulnerable population in endemic countries. It is based on the evidence that well-trained communities health workers can provide prompt and adequate care to patients close to their homes. The strategy has been shown to reduce malaria mortality and severe morbidity and has been adopted by the World Health Organization as a cornerstone of malaria control in Africa. However, the potential fall-out of this community-based strategy on the work burden at the peripheral health facilities level has never been investigated. A two-arm interventional study was conducted in a rural health district of Burkina Faso. The HMM strategy has been implemented in seven community clinics catchment's area (intervention arm). For the other seven community clinics in the control arm, no HMM intervention was implemented. In each of the study arms, presumptive treatment was provided for episodes of fevers/malaria (defined operationally as malaria). The study drug was artemether-lumefantrine, which was sold at a subsidized price by community health workers/Key opinion leaders at the community level and by the pharmacists at the health facility level. The outcome measured was the proportion of malaria cases among all health facility attendance (all causes diseases) in both arms throughout the high transmission season. A total of 7,621 children were enrolled in the intervention arm and 7,605 in the control arm. During the study period, the proportions of malaria cases among all health facility attendance (all causes diseases) were 21.0%, (445/2,111, 95% CI [19.3%-22.7%]) and 70.7% (2,595/3,671, 95% CI 68.5%-71.5%), respectively in the intervention and control arms (p < 0.0001). The relative risk ratio for a fever/malaria episode to be treated at the HF level was 30% (0.30 < RR < 0.32). The number of malaria episodes treated in the intervention arm was much higher than in the control arm (6,661 vs. 2,595), with malaria accounting for 87.4% of all disease episodes recorded in the intervention area and for 34.1% in the control area (P < 0.0001). Of all the malaria cases treated in the intervention arm, only 6.7% were treated at the health facility level. These findings suggest that implementation of HMM, by reducing the workload in health facilities, might contributes to an overall increase of the performance of the peripheral health facilities.

Implementation of malaria dynamic models in municipality level early warning systems in Colombia. Part I: description of study sites.

PubMed

Ruiz, Daniel; Cerón, Viviana; Molina, Adriana M; Quiñónes, Martha L; Jiménez, Mónica M; Ahumada, Martha; Gutiérrez, Patricia; Osorio, Salua; Mantilla, Gilma; Connor, Stephen J; Thomson, Madeleine C

2014-07-01

As part of the Integrated National Adaptation Pilot project and the Integrated Surveillance and Control System, the Colombian National Institute of Health is working on the design and implementation of a Malaria Early Warning System framework, supported by seasonal climate forecasting capabilities, weather and environmental monitoring, and malaria statistical and dynamic models. In this report, we provide an overview of the local ecoepidemiologic settings where four malaria process-based mathematical models are currently being implemented at a municipal level. The description includes general characteristics, malaria situation (predominant type of infection, malaria-positive cases data, malaria incidence, and seasonality), entomologic conditions (primary and secondary vectors, mosquito densities, and feeding frequencies), climatic conditions (climatology and long-term trends), key drivers of epidemic outbreaks, and non-climatic factors (populations at risk, control campaigns, and socioeconomic conditions). Selected pilot sites exhibit different ecoepidemiologic settings that must be taken into account in the development of the integrated surveillance and control system. © The American Society of Tropical Medicine and Hygiene.

Spatial trend, environmental and socioeconomic factors associated with malaria prevalence in Chennai

PubMed Central

2014-01-01

Background Urban malaria is considered to be one of the most significant infectious diseases due to varied socioeconomic problems especially in tropical countries like India. Among the south Indian cities, Chennai is endemic for malaria. The present study aimed to identify the hot spots of malaria prevalence and the relationship with other factors in Chennai during 2005-2011. Methods Data on zone-wise and ward-wise monthly malaria positive cases were collected from the Vector Control Office, Chennai Corporation, for the year 2005 to 2011 and verified using field data. This data was used to calculate the prevalence among thousand people. Hotspot analysis for all the years in the study period was done to observe the spatial trend. Association of environmental factors like altitude, population density and climatic variables was assessed using ArcGIS 9.3 version and SPSS 11.5. Pearson’s correlation of climate parameters at 95% and 99% was considered to be the most significant. Social parameters of the highly malaria prone region were evaluated through a structured random questionnaire field survey. Results Among the ten zones of Chennai Corporation, Basin Bridge zone showed high malaria prevalence during the study period. The ‘hotspot’ analysis of malaria prevalence showed the emergence of newer hotspots in the Adyar zone. These hotspots of high prevalence are places of moderately populated and moderately elevated areas. The prevalence of malaria in Chennai could be due to rainfall and temperature, as there is a significant correlation with monthly rainfall and one month lag of monthly mean temperature. Further it has been observed that the socioeconomic status of people in the malaria hotspot regions and unhygienic living conditions were likely to aggravate the malaria problem. Conclusion Malaria hotspots will be the best method to use for targeting malaria control activities. Proper awareness and periodical monitoring of malaria is one of the quintessential steps to control this infectious disease. It has been argued that identifying the key environmental conditions favourable for the occurrence and spread of malaria must be integrated and documented to aid future predictions of malaria in Chennai. PMID:24400592

Spatial trend, environmental and socioeconomic factors associated with malaria prevalence in Chennai.

PubMed

Kumar, Divya Subash; Andimuthu, Ramachandran; Rajan, Rupa; Venkatesan, Mada Suresh

2014-01-08

Urban malaria is considered to be one of the most significant infectious diseases due to varied socioeconomic problems especially in tropical countries like India. Among the south Indian cities, Chennai is endemic for malaria. The present study aimed to identify the hot spots of malaria prevalence and the relationship with other factors in Chennai during 2005-2011. Data on zone-wise and ward-wise monthly malaria positive cases were collected from the Vector Control Office, Chennai Corporation, for the year 2005 to 2011 and verified using field data. This data was used to calculate the prevalence among thousand people. Hotspot analysis for all the years in the study period was done to observe the spatial trend. Association of environmental factors like altitude, population density and climatic variables was assessed using ArcGIS 9.3 version and SPSS 11.5. Pearson's correlation of climate parameters at 95% and 99% was considered to be the most significant. Social parameters of the highly malaria prone region were evaluated through a structured random questionnaire field survey. Among the ten zones of Chennai Corporation, Basin Bridge zone showed high malaria prevalence during the study period. The 'hotspot' analysis of malaria prevalence showed the emergence of newer hotspots in the Adyar zone. These hotspots of high prevalence are places of moderately populated and moderately elevated areas. The prevalence of malaria in Chennai could be due to rainfall and temperature, as there is a significant correlation with monthly rainfall and one month lag of monthly mean temperature. Further it has been observed that the socioeconomic status of people in the malaria hotspot regions and unhygienic living conditions were likely to aggravate the malaria problem. Malaria hotspots will be the best method to use for targeting malaria control activities. Proper awareness and periodical monitoring of malaria is one of the quintessential steps to control this infectious disease. It has been argued that identifying the key environmental conditions favourable for the occurrence and spread of malaria must be integrated and documented to aid future predictions of malaria in Chennai.

Malaria in Wanokaka and Loli sub-districts, West Sumba District, East Nusa Tenggara Province, Indonesia.

PubMed

Syafruddin, Din; Asih, Puji B S; Coutrier, Farah N; Trianty, Leily; Noviyanti, Rintis; Luase, Yaveth; Sumarto, Wajiyo; Caley, Marten; van der Ven, Andre J A M; Sauerwein, Robert W

2006-05-01

Malaria has long been known as one of the major public health problems in West Sumba District, East Nusa Tenggara Province, Indonesia. To obtain baseline data for establishment of a suitable malaria control program in the area, malariometric surveys were conducted in two sub-districts, Wanokaka and Loli, during the periods of January, May, and August 2005. The survey included three selected villages in each sub-district, and blood smear analyses of 701, 921, and 894 randomly selected subjects in January, May, and August revealed 30.5%, 25.3%, and 28.2% malaria positives, respectively, consisting mainly of Plasmodium falciparum and P. vivax, and in a few cases, P. malariae. Analysis of malaria prevalence at different age groups clearly reflected the common phenomenon that younger individuals are more vulnerable by infection of either P. falciparum or P. vivax. In falciparum malaria, the frequency of cases carrying gametocytes was also relatively high involving all age groups. The findings indicate that the malaria incidence and transmission in the area are relatively high and that further exploration is warranted to establish a precise malaria control program.

Forecasting paediatric malaria admissions on the Kenya Coast using rainfall.

PubMed

Karuri, Stella Wanjugu; Snow, Robert W

2016-01-01

Malaria is a vector-borne disease which, despite recent scaled-up efforts to achieve control in Africa, continues to pose a major threat to child survival. The disease is caused by the protozoan parasite Plasmodium and requires mosquitoes and humans for transmission. Rainfall is a major factor in seasonal and secular patterns of malaria transmission along the East African coast. The goal of the study was to develop a model to reliably forecast incidences of paediatric malaria admissions to Kilifi District Hospital (KDH). In this article, we apply several statistical models to look at the temporal association between monthly paediatric malaria hospital admissions, rainfall, and Indian Ocean sea surface temperatures. Trend and seasonally adjusted, marginal and multivariate, time-series models for hospital admissions were applied to a unique data set to examine the role of climate, seasonality, and long-term anomalies in predicting malaria hospital admission rates and whether these might become more or less predictable with increasing vector control. The proportion of paediatric admissions to KDH that have malaria as a cause of admission can be forecast by a model which depends on the proportion of malaria admissions in the previous 2 months. This model is improved by incorporating either the previous month's Indian Ocean Dipole information or the previous 2 months' rainfall. Surveillance data can help build time-series prediction models which can be used to anticipate seasonal variations in clinical burdens of malaria in stable transmission areas and aid the timing of malaria vector control.

Malaria in Sucre State, Venezuela.

PubMed

Zimmerman, R H

2000-01-01

The author reviews the malaria research program in Sucre State, Venezuela, taking an ecosystem approach. The goal was to determine which methods could have been introduced at the onset that would have made the study more ecological and interdisciplinary. Neither an ecosystem approach nor integrated disease control were in place at the time of the study. This study began to introduce an ecosystem approach when two contrasting ecosystems in Sucre State were selected for study and vector control methods were implemented based on research results. The need to have a health policy in place with an eco-health approach is crucial to the success of research and control. The review suggests that sustainability is low when not all the stakeholders are involved in the design and implementation of the research and control strategy development. The lack of community involvement makes sustainability doubtful. The author concludes that there were two interdependent challenges for malaria control: development of an ecosystem approach for malaria research and control, and the implementation of an integrated disease control strategy, with malaria as one of the important health issues.

Malaria control in rural Malawi: implementing peer health education for behaviour change.

PubMed

Malenga, Tumaini; Kabaghe, Alinune Nathanael; Manda-Taylor, Lucinda; Kadama, Asante; McCann, Robert S; Phiri, Kamija Samuel; van Vugt, Michèle; van den Berg, Henk

2017-11-20

Interventions to reduce malaria burden are effective if communities use them appropriately and consistently. Several tools have been suggested to promote uptake and use of malaria control interventions. Community workshops on malaria, using the 'Health Animator' approach, are a potential behaviour change strategy for malaria control. The strategy aims to influence a change in mind-set of vulnerable populations to encourage self-reliance, using community volunteers known as Health Animators. The aim of the paper is to describe the process of implementing community workshops on malaria by Health Animators to improve uptake and use of malaria control interventions in rural Malawi. This is a descriptive study reporting feasibility, acceptability, appropriateness and fidelity of using Health Animator-led community workshops for malaria control. Quantitative data were collected from self-reporting and researcher evaluation forms. Qualitative assessments were done with Health Animators, using three focus groups (October-December 2015) and seven in-depth interviews (October 2016-February 2017). Seventy seven health Animators were trained from 62 villages. A total of 2704 workshops were conducted, with consistent attendance from January 2015 to June 2017, representing 10-17% of the population. Attendance was affected by social responsibilities and activities, relationship of the village leaders and their community and involvement of Community Health Workers. Active discussion and participation were reported as main strengths of the workshops. Health Animators personally benefited from the mind-set change and were proactive peer influencers in the community. Although the information was comprehended and accepted, availability of adequate health services was a challenge for maintenance of behaviour change. Community workshops on malaria are a potential tool for influencing a positive change in behaviour towards malaria, and applicable for other health problems in rural African communities. Social structures of influence and power dynamics affect community response. There is need for systematic monitoring of community workshops to ensure implementation fidelity and strengthening health systems to ensure sustainability of health behaviour change.

Analysis of Historical Trends and Recent Elimination of Malaria from Sri Lanka and Its Applicability for Malaria Control in Other Countries

PubMed Central

Wijesundere, Dilkushi Anula; Ramasamy, Ranjan

2017-01-01

Sri Lanka is a tropical island located South of India in the Indian Ocean. Malaria has been prevalent in the island for centuries but the country succeeded in eliminating the disease in 2013. Factors governing the past endemicity of malaria and its successful elimination from Sri Lanka in 2013 are analyzed. There is evidence that malaria might have been first introduced in the thirteenth century into a dry zone area with extensive irrigation works. Regular widespread epidemics of the disease have been documented in the twentieth century. The island nature of Sri Lanka, generally low transmission rates, widespread and accessible government hospitals and clinics that provide free and readily available diagnosis and treatment for malaria, adequate financial support and commitment to the Antimalaria Campaign (AMC), national and decentralized malaria control efforts sustained over a long period by dedicated and competent AMC staff, and the absence of zoonotic malaria are recognized as key factors responsible for eliminating malaria from Sri Lanka. These factors are analyzed in the context of their relevance to the present malaria elimination efforts in other countries with the overall aim of globally eradicating the disease. PMID:28894732

Analysis of Historical Trends and Recent Elimination of Malaria from Sri Lanka and Its Applicability for Malaria Control in Other Countries.

PubMed

Wijesundere, Dilkushi Anula; Ramasamy, Ranjan

2017-01-01

Sri Lanka is a tropical island located South of India in the Indian Ocean. Malaria has been prevalent in the island for centuries but the country succeeded in eliminating the disease in 2013. Factors governing the past endemicity of malaria and its successful elimination from Sri Lanka in 2013 are analyzed. There is evidence that malaria might have been first introduced in the thirteenth century into a dry zone area with extensive irrigation works. Regular widespread epidemics of the disease have been documented in the twentieth century. The island nature of Sri Lanka, generally low transmission rates, widespread and accessible government hospitals and clinics that provide free and readily available diagnosis and treatment for malaria, adequate financial support and commitment to the Antimalaria Campaign (AMC), national and decentralized malaria control efforts sustained over a long period by dedicated and competent AMC staff, and the absence of zoonotic malaria are recognized as key factors responsible for eliminating malaria from Sri Lanka. These factors are analyzed in the context of their relevance to the present malaria elimination efforts in other countries with the overall aim of globally eradicating the disease.

High Levels of Plasmodium falciparum Rosetting in All Clinical Forms of Severe Malaria in African Children

PubMed Central

Doumbo, Ogobara K.; Thera, Mahamadou A.; Koné, Abdoulaye K.; Raza, Ahmed; Tempest, Louisa J.; Lyke, Kirsten E.; Plowe, Christopher V.; Rowe, J. Alexandra

2010-01-01

Plasmodium falciparum rosetting (the spontaneous binding of infected erythrocytes to uninfected erythrocytes) is a well-recognized parasite virulence factor. However, it is currently unclear whether rosetting is associated with all clinical forms of severe malaria, or only with specific syndromes such as cerebral malaria. We investigated the relationship between rosetting and clinical malaria in 209 Malian children enrolled in a case-control study of severe malaria. Rosetting was significantly higher in parasite isolates from severe malaria cases compared with non-severe hyperparasitemia and uncomplicated malaria controls (F2,117 = 8.15, P < 0.001). Analysis of sub-categories of severe malaria (unrousable coma, severe anemia, non-comatose neurological impairment, repeated seizures or a small heterogeneous group with signs of renal failure or jaundice) showed high levels of rosetting in all sub-categories, and no statistically significant differences in rosetting between sub-categories (F4,67 = 1.28, P = 0.28). Thus rosetting may contribute to the pathogenesis of all severe malaria syndromes in African children, and interventions to disrupt rosetting could be potential adjunctive therapies for all forms of severe malaria in Africa. PMID:19996426

Attacking the mosquito on multiple fronts: Insights from the Vector Control Optimization Model (VCOM) for malaria elimination.

PubMed

Kiware, Samson S; Chitnis, Nakul; Tatarsky, Allison; Wu, Sean; Castellanos, Héctor Manuel Sánchez; Gosling, Roly; Smith, David; Marshall, John M

2017-01-01

Despite great achievements by insecticide-treated nets (ITNs) and indoor residual spraying (IRS) in reducing malaria transmission, it is unlikely these tools will be sufficient to eliminate malaria transmission on their own in many settings today. Fortunately, field experiments indicate that there are many promising vector control interventions that can be used to complement ITNs and/or IRS by targeting a wide range of biological and environmental mosquito resources. The majority of these experiments were performed to test a single vector control intervention in isolation; however, there is growing evidence and consensus that effective vector control with the goal of malaria elimination will require a combination of interventions. We have developed a model of mosquito population dynamic to describe the mosquito life and feeding cycles and to optimize the impact of vector control intervention combinations at suppressing mosquito populations. The model simulations were performed for the main three malaria vectors in sub-Saharan Africa, Anopheles gambiae s.s, An. arabiensis and An. funestus. We considered areas having low, moderate and high malaria transmission, corresponding to entomological inoculation rates of 10, 50 and 100 infective bites per person per year, respectively. In all settings, we considered baseline ITN coverage of 50% or 80% in addition to a range of other vector control tools to interrupt malaria transmission. The model was used to sweep through parameters space to select the best optimal intervention packages. Sample model simulations indicate that, starting with ITNs at a coverage of 50% (An. gambiae s.s. and An. funestus) or 80% (An. arabiensis) and adding interventions that do not require human participation (e.g. larviciding at 80% coverage, endectocide treated cattle at 50% coverage and attractive toxic sugar baits at 50% coverage) may be sufficient to suppress all the three species to an extent required to achieve local malaria elimination. The Vector Control Optimization Model (VCOM) is a computational tool to predict the impact of combined vector control interventions at the mosquito population level in a range of eco-epidemiological settings. The model predicts specific combinations of vector control tools to achieve local malaria elimination in a range of eco-epidemiological settings and can assist researchers and program decision-makers on the design of experimental or operational research to test vector control interventions. A corresponding graphical user interface is available for national malaria control programs and other end users.

From Recipients to Partners: Children in Malaria Education in Uganda

ERIC Educational Resources Information Center

Nakiwala, Aisha Sembatya

2016-01-01

Purpose: Health education that integrates community participation is essential for malaria control. However, children's participation is not generally as active as that of adults, thus turning children into recipients, as opposed to partners in malaria control. The purpose of this paper is to develop a better understanding of how children can…

Effective Program Management: A Cornerstone of Malaria Elimination

PubMed Central

Gosling, Jonathan; Case, Peter; Tulloch, Jim; Chandramohan, Daniel; Wegbreit, Jennifer; Newby, Gretchen; Gueye, Cara Smith; Koita, Kadiatou; Gosling, Roly

2015-01-01

Effective program management is essential for successful elimination of malaria. In this perspective article, evidence surrounding malaria program management is reviewed by management science and malaria experts through a literature search of published and unpublished gray documents and key informant interviews. Program management in a malaria elimination setting differs from that in a malaria control setting in a number of ways, although knowledge and understanding of these distinctions are lacking. Several core features of successful health program management are critical to achieve elimination, including effective leadership and supervision at all levels, sustained political and financial commitment, reliable supply and control of physical resources, effective management of data and information, appropriate incentives, and consistent accountability. Adding to the complexity, the requirements of an elimination program may conflict with those of a control regimen. Thus, an additional challenge is successfully managing program transitions along the continuum from control to elimination to prevention of reintroduction. This article identifies potential solutions to these challenges by exploring managerial approaches that are flexible, relevant, and sustainable in various cultural and health system contexts. PMID:26013372

[Application of health education of house-to-house visit in malaria prevention and control].

PubMed

Zhou, Wen-gang; Qu, Yan; Wang, Wen-guang; Tang, Song-yuan

2014-10-01

To evaluate the effects of health education of house-to-house visit in malaria prevention and control in the border and minority areas. A health education of house-to-house visit in malaria prevention and control was carried out, and baseline and follow up surveys were conducted by qualitative and quantitative methods to document the changes of local villagers' knowledge, attitudes and behaviors (KAP) of malaria prevention and control in 2 counties of Yunnan Province, and the results before and after the interventions were analyzed and compared. After the intervention, the cognition rates about malaria symptoms and signs, transmission mode, preventive measures and health-seeking behaviors were 99.3%, 98.9%, 79.9% and 99.3% respectively in the local residents, and those were 39.2%, 8.2%, 47.0% and 49.9% respectively before the intervention, and all the differences were statistically significant (P all < 0.01). KAP related to malaria among the targeting population has improved after the interventions and the house-to-house visit is an effective community-based health education approach.

Impact of pyrethroid resistance on operational malaria control in Malawi

PubMed Central

Wondji, Charles S.; Coleman, Michael; Kleinschmidt, Immo; Mzilahowa, Themba; Irving, Helen; Ndula, Miranda; Rehman, Andrea; Morgan, John; Barnes, Kayla G.; Hemingway, Janet

2012-01-01

The impact of insecticide resistance on insect-borne disease programs is difficult to quantify. The possibility of eliminating malaria in high-transmission settings is heavily dependent on effective vector control reducing disease transmission rates. Pyrethroids are the dominant insecticides used for malaria control, with few options for their replacement. Their failure will adversely affect our ability to control malaria. Pyrethroid resistance has been selected in Malawi over the last 3 y in the two major malaria vectors Anopheles gambiae and Anopheles funestus, with a higher frequency of resistance in the latter. The resistance in An. funestus is metabolically based and involves the up-regulation of two duplicated P450s. The same genes confer resistance in Mozambican An. funestus, although the levels of up-regulation differ. The selection of resistance over 3 y has not increased malaria transmission, as judged by annual point prevalence surveys in 1- to 4-y-old children. This is true in areas with long-lasting insecticide-treated nets (LLINs) alone or LLINs plus pyrethroid-based insecticide residual spraying (IRS). However, in districts where IRS was scaled up, it did not produce the expected decrease in malaria prevalence. As resistance increases in frequency from this low initial level, there is the potential for vector population numbers to increase with a concomitant negative impact on control efficacy. This should be monitored carefully as part of the operational activities in country. PMID:23118337

Genetic Structure of Plasmodium falciparum and Elimination of Malaria, Comoros Archipelago

PubMed Central

Rebaudet, Stanislas; Bogreau, Hervé; Silaï, Rahamatou; Lepère, Jean-François; Bertaux, Lionel; Pradines, Bruno; Delmont, Jean; Gautret, Philippe; Parola, Philippe

2010-01-01

The efficacy of malaria control and elimination on islands may depend on the intensity of new parasite inflow. On the Comoros archipelago, where falciparum malaria remains a major public health problem because of spread of drug resistance and insufficient malaria control, recent interventions for malaria elimination were planned on Moheli, 1 of 4 islands in the Comoros archipelago. To assess the relevance of such a local strategy, we performed a population genetics analysis by using multilocus microsatellite and resistance genotyping of Plasmodium falciparum sampled from each island of the archipelago. We found a contrasted population genetic structure explained by geographic isolation, human migration, malaria transmission, and drug selective pressure. Our findings suggest that malaria elimination interventions should be implemented simultaneously on the entire archipelago rather than restricted to 1 island and demonstrate the necessity for specific chemoresistance surveillance on each of the 4 Comorian islands. PMID:21029525

Infectivity of Chronic Malaria Infections and Its Consequences for Control and Elimination.

PubMed

Aguas, Ricardo; Maude, Richard J; Gomes, M Gabriela M; White, Lisa J; White, Nicholas J; Dondorp, Arjen M

2018-05-10

Assessing the importance of targeting the chronic Plasmodium falciparum malaria reservoir is pivotal as the world moves toward malaria eradication. Through the lens of a mathematical model, we show how, for a given malaria prevalence, the relative infectivity of chronic individuals determines what intervention tools are predicted be the most effective. Crucially, in a large part of the parameter space where elimination is theoretically possible, it can be achieved solely through improved case management. However, there are a significant number of settings where malaria elimination requires not only good vector control but also a mass drug administration campaign. Quantifying the relative infectiousness of chronic malaria across a range of epidemiological settings would provide essential information for the design of effective malaria elimination strategies. Given the difficulties obtaining this information, we also provide a set of epidemiological metrics that can be used to guide policy in the absence of such data.

Barriers to malaria control in rural south-west Timor-Leste: a qualitative analysis.

PubMed

Neave, Penny E; Soares, Maria L

2014-01-01

Malaria is an important health problem in Timor-Leste. Although funding has been provided to reduce the burden of this disease, few studies have investigated whether this has improved malaria-related knowledge, management of symptoms, and treatment in rural communities. The aim of this study was to explore the perceptions and practices undertaken in relation to all aspects of malaria control by members of two rural communities in Timor-Leste. A qualitative study was undertaken in two rural hamlets in Timor-Leste. Research methods included transect walks, focus groups and semi-structured interviews. Content analysis was used to identify themes. The location of the hamlets near rice fields, leaking taps, inadequate water supplies and dumping of waste from the local hospital provided opportunities for mosquitoes to breed. Most participants were aware of the link between mosquitoes and malaria, but a lack of control over their environment was a major barrierto preventing malaria. The distribution ofbed nets had occurred once, and was the only intervention undertaken bythe National Malaria Control Programme. However, limiting the distribution of bed nets to pregnant women and children aged under 5 years had resulted in some focus group respondents believing that only those in these groups could be affected by malaria. Self-diagnosis and home treatmentwere common. Treatment for unresolved infections depended on access to transport funds, and belief in the power of traditional healers. Improvements in infrastructure, empowerment of rural communities, and better access to treatment are recommended if the incidence of malaria is to be reduced throughout the country.

[Plan to improve malaria control towards its elimination in Mesoamerica].

PubMed

Rodríguez, Mario Henry; Betanzos-Reyes, Angel Francisco

2011-01-01

To develop a plan to strengthen the control of malaria towards its elimination. In 2009, under the coordination of the National Public HealthInstitute ofMexico, atransdisciplinary equipment of technical and operative experts was conformed to carry out a situational analysis of malaria and control programs and for the selection of effective practices of intervention that would be incorporated to the plan, within the framework of an exercise in Theory of Change. Criteria for thestratificationof thelocalities, based ontheirtransmission characteristics were established. The structural and operative limitations of the control programs were identified. A plan of interventions was elaborated to improve the coverage of epidemiological surveillance, anti-malaria interventions and opportune diagnosis and treatment of cases. The plan delineates progressive phases of implementation: reorganization, intensification of interventions and evaluation of elimination feasibility. The adoption of a regional strategic plan will provide guidance and administrative elements to conform a system that coordinates the activities of the national control programs and facilitate the elimination of malaria in the region.

Progress towards malaria elimination in Zimbabwe with special reference to the period 2003-2015.

PubMed

Sande, Shadreck; Zimba, Moses; Mberikunashe, Joseph; Tangwena, Andrew; Chimusoro, Anderson

2017-07-24

An intensive effort to control malaria in Zimbabwe has produced dramatic reductions in the burden of the disease over the past 13 years. The successes have prompted the Zimbabwe's National Malaria Control Programme to commit to elimination of malaria. It is critical to analyse the changes in the morbidity trends based on surveillance data, and scrutinize reorientation to strategies for elimination. This is a retrospective study of available Ministry of Health surveillance data and programme reports, mostly from 2003 to 2015. Malaria epidemiological data were drawn from the National Health Information System database. Data on available resources, malaria control strategies, morbidity and mortality trends were analysed, and opportunities for Zimbabwe malaria elimination agenda was perused. With strong government commitment and partner support, the financial gap for malaria programming shrank by 91.4% from about US$13 million in 2012 to US$1 million in 2015. Vector control comprises indoor residual house spraying (IRS) and long-lasting insecticidal nets, and spray coverage increased from 28% in 2003 to 95% in 2015. Population protected by IRS increased also from 20 to 96% for the same period. In 2009, diagnostics improved from clinical to parasitological confirmation either by rapid diagnostic tests or microscopy. Artemisinin-based combination therapy was used to treat malaria following chloroquine resistance in 2000, and sulfadoxine-pyrimethamine in 2004. In 2003, there were 155 malaria cases per 1000 populations reported from all health facilities throughout the country. The following decade witnessed a substantial decline in cases to only 22 per 1000 populations in 2012. A resurgence was reported in 2013 (29/1000) and 2014 (39/1000), thereafter morbidity declined to 29 cases per 1000 populations, only to the same level as in 2013. Overall, morbidity declined by 81% from 2003 to 2015. Inpatient malaria deaths per 100,000 populations doubled in 4 years, from 2/100,000 to 4/100,000 populations in 2012-2015 respectively. Twenty of the 47 moderate to high burdened districts were upgraded from control to malaria pre-elimination between 2012 and 2015. A significant progress to reduce malaria transmission in Zimbabwe has been made. While a great potential and opportunities to eliminate malaria in the country exist, elimination is not a business as usual approach. Instead, it needs an improved, systematic and new programmatic strategy supported strongly by political will, sustained funding, good leadership, community engagement, and a strong monitoring and evaluation system all year round until the cessation of local transmission.

The Epidemiology of Imported Malaria in Taiwan between 2002–2013: The Importance of Sensitive Surveillance and Implications for Pre-Travel Medical Advice

PubMed Central

Chen, Shou-Chien; Chang, Hsiao-Ling; Chen, Kow-Tong

2014-01-01

The purpose of this study was to assess the epidemiology of imported malaria in Taiwan between 2002 and 2013. We analyzed the national data recorded by the Taiwan Centers for Disease Control (Taiwan CDC). Malaria cases were diagnosed by blood films, polymerase chain reaction, or rapid diagnostic tests. The risk of re-establishment of malarial transmission in Taiwan was assessed. A total of 229 malaria cases were included in our analysis. All of the cases were imported. One hundred and ninety-two cases (84%) were diagnosed within 13 days of the start of symptoms/signs; 43% of these cases were acquired in Africa and 44% were acquired in Asia. Plasmodium falciparum was responsible for the majority (56%) of these cases. Travel to an endemic area was associated with the acquisition of malaria. The malaria importation rate was 2.36 per 1,000,000 travelers (range 1.20–5.74). The reproductive number under control (Rc) was 0. No endemic transmission of malaria in Taiwan was identified. This study suggests that a vigilant surveillance system, vector-control efforts, case management, and an educational approach focused on travelers and immigrants who visit malaria endemic countries are needed to prevent outbreaks and sustain the elimination of malaria in Taiwan. PMID:24871257

Increasing Incidence of Plasmodium knowlesi Malaria following Control of P. falciparum and P. vivax Malaria in Sabah, Malaysia

PubMed Central

William, Timothy; Rahman, Hasan A.; Jelip, Jenarun; Ibrahim, Mohammad Y.; Menon, Jayaram; Grigg, Matthew J.; Yeo, Tsin W.; Anstey, Nicholas M.; Barber, Bridget E.

2013-01-01

Background The simian parasite Plasmodium knowlesi is a common cause of human malaria in Malaysian Borneo and threatens the prospect of malaria elimination. However, little is known about the emergence of P. knowlesi, particularly in Sabah. We reviewed Sabah Department of Health records to investigate the trend of each malaria species over time. Methods Reporting of microscopy-diagnosed malaria cases in Sabah is mandatory. We reviewed all available Department of Health malaria notification records from 1992–2011. Notifications of P. malariae and P. knowlesi were considered as a single group due to microscopic near-identity. Results From 1992–2011 total malaria notifications decreased dramatically, with P. falciparum peaking at 33,153 in 1994 and decreasing 55-fold to 605 in 2011, and P. vivax peaking at 15,857 in 1995 and decreasing 25-fold to 628 in 2011. Notifications of P. malariae/P. knowlesi also demonstrated a peak in the mid-1990s (614 in 1994) before decreasing to ≈100/year in the late 1990s/early 2000s. However, P. malariae/P. knowlesi notifications increased >10-fold between 2004 (n = 59) and 2011 (n = 703). In 1992 P. falciparum, P. vivax and P. malariae/P. knowlesi monoinfections accounted for 70%, 24% and 1% respectively of malaria notifications, compared to 30%, 31% and 35% in 2011. The increase in P. malariae/P. knowlesi notifications occurred state-wide, appearing to have begun in the southwest and progressed north-easterly. Conclusions A significant recent increase has occurred in P. knowlesi notifications following reduced transmission of the human Plasmodium species, and this trend threatens malaria elimination. Determination of transmission dynamics and risk factors for knowlesi malaria is required to guide measures to control this rising incidence. PMID:23359830

Lethal and Pre-Lethal Effects of a Fungal Biopesticide Contribute to Substantial and Rapid Control of Malaria Vectors

PubMed Central

Blanford, Simon; Shi, Wangpeng; Christian, Riann; Marden, James H.; Koekemoer, Lizette L.; Brooke, Basil D.; Coetzee, Maureen; Read, Andrew F.; Thomas, Matthew B.

2011-01-01

Rapidly emerging insecticide resistance is creating an urgent need for new active ingredients to control the adult mosquitoes that vector malaria. Biopesticides based on the spores of entomopathogenic fungi have shown considerable promise by causing very substantial mortality within 7–14 days of exposure. This mortality will generate excellent malaria control if there is a high likelihood that mosquitoes contact fungi early in their adult lives. However, where contact rates are lower, as might result from poor pesticide coverage, some mosquitoes will contact fungi one or more feeding cycles after they acquire malaria, and so risk transmitting malaria before the fungus kills them. Critics have argued that ‘slow acting’ fungal biopesticides are, therefore, incapable of delivering malaria control in real-world contexts. Here, utilizing standard WHO laboratory protocols, we demonstrate effective action of a biopesticide much faster than previously reported. Specifically, we show that transient exposure to clay tiles sprayed with a candidate biopesticide comprising spores of a natural isolate of Beauveria bassiana, could reduce malaria transmission potential to zero within a feeding cycle. The effect resulted from a combination of high mortality and rapid fungal-induced reduction in feeding and flight capacity. Additionally, multiple insecticide-resistant lines from three key African malaria vector species were completely susceptible to fungus. Thus, fungal biopesticides can block transmission on a par with chemical insecticides, and can achieve this where chemical insecticides have little impact. These results support broadening the current vector control paradigm beyond fast-acting chemical toxins. PMID:21897846

Malaria early warning tool: linking inter-annual climate and malaria variability in northern Guadalcanal, Solomon Islands.

PubMed

Smith, Jason; Tahani, Lloyd; Bobogare, Albino; Bugoro, Hugo; Otto, Francis; Fafale, George; Hiriasa, David; Kazazic, Adna; Beard, Grant; Amjadali, Amanda; Jeanne, Isabelle

2017-11-21

Malaria control remains a significant challenge in the Solomon Islands. Despite progress made by local malaria control agencies over the past decade, case rates remain high in some areas of the country. Studies from around the world have confirmed important links between climate and malaria transmission. This study focuses on understanding the links between malaria and climate in Guadalcanal, Solomon Islands, with a view towards developing a climate-based monitoring and early warning for periods of enhanced malaria transmission. Climate records were sourced from the Solomon Islands meteorological service (SIMS) and historical malaria case records were sourced from the National Vector-Borne Disease Control Programme (NVBDCP). A declining trend in malaria cases over the last decade associated with improved malaria control was adjusted for. A stepwise regression was performed between climate variables and climate-associated malaria transmission (CMT) at different lag intervals to determine where significant relationships existed. The suitability of these results for use in a three-tiered categorical warning system was then assessed using a Mann-Whitney U test. Of the climate variables considered, only rainfall had a consistently significant relationship with malaria in North Guadalcanal. Optimal lag intervals were determined for prediction using R 2 skill scores. A highly significant negative correlation (R = - 0.86, R 2  = 0.74, p < 0.05, n = 14) was found between October and December rainfall at Honiara and CMT in northern Guadalcanal for the subsequent January-June. This indicates that drier October-December periods are followed by higher malaria transmission periods in January-June. Cross-validation emphasized the suitability of this relationship for forecasting purposes [Formula: see text]  as did Mann-Whitney U test results showing that rainfall below or above specific thresholds was significantly associated with above or below normal malaria transmission, respectively. This study demonstrated that rainfall provides the best predictor of malaria transmission in North Guadalcanal. This relationship is thought to be underpinned by the unique hydrological conditions in northern Guadalcanal which allow sandbars to form across the mouths of estuaries which act to develop or increase stagnant brackish marshes in low rainfall periods. These are ideal habitats for the main mosquito vector, Anopheles farauti. High rainfall accumulations result in the flushing of these habitats, reducing their viability. The results of this study are now being used as the basis of a malaria early warning system which has been jointly implemented by the SIMS, NVBDCP and the Australian Bureau of Meteorology.

Malaria Control Interventions Contributed to Declines in Malaria Parasitemia, Severe Anemia, and All-Cause Mortality in Children Less Than 5 Years of Age in Malawi, 2000-2010.

PubMed

Hershey, Christine L; Florey, Lia S; Ali, Doreen; Bennett, Adam; Luhanga, Misheck; Mathanga, Don P; Salgado, S René; Nielsen, Carrie F; Troell, Peter; Jenda, Gomezgani; Yé, Yazoume; Bhattarai, Achuyt

2017-09-01

Malaria control intervention coverage increased nationwide in Malawi during 2000-2010. Trends in intervention coverage were assessed against trends in malaria parasite prevalence, severe anemia (hemoglobin < 8 g/dL), and all-cause mortality in children under 5 years of age (ACCM) using nationally representative household surveys. Associations between insecticide-treated net (ITN) ownership, malaria morbidity, and ACCM were also assessed. Household ITN ownership increased from 27.4% (95% confidence interval [CI] = 25.9-29.0) in 2004 to 56.8% (95% CI = 55.6-58.1) in 2010. Similarly intermittent preventive treatment during pregnancy coverage increased from 28.2% (95% CI = 26.7-29.8) in 2000 to 55.0% (95% CI = 53.4-56.6) in 2010. Malaria parasite prevalence decreased significantly from 60.5% (95% CI = 53.0-68.0) in 2001 to 20.4% (95% CI = 15.7-25.1) in 2009 in children aged 6-35 months. Severe anemia prevalence decreased from 20.4% (95% CI: 17.3-24.0) in 2004 to 13.1% (95% CI = 11.0-15.4) in 2010 in children aged 6-23 months. ACCM decreased 41%, from 188.6 deaths per 1,000 live births (95% CI = 179.1-198.0) during 1996-2000, to 112.1 deaths per 1,000 live births (95% CI = 105.8-118.5) during 2006-2010. When controlling for other covariates in random effects logistic regression models, household ITN ownership was protective against malaria parasitemia in children (odds ratio [OR] = 0.81, 95% CI = 0.72-0.92) and severe anemia (OR = 0.82, 95% CI = 0.72-0.94). After considering the magnitude of changes in malaria intervention coverage and nonmalaria factors, and given the contribution of malaria to all-cause mortality in malaria-endemic countries, the substantial increase in malaria control interventions likely improved child survival in Malawi during 2000-2010.

Eliminating Plasmodium falciparum in Hainan, China: a study on the use of behavioural change communication intervention to promote malaria prevention in mountain worker populations.

PubMed

He, Chang-hua; Hu, Xi-min; Wang, Guang-ze; Zhao, Wei; Sun, Ding-wei; Li, Yu-chun; Chen, Chun-xiang; Du, Jian-wei; Wang, Shan-qing

2014-07-13

In the island of Hainan, the great majority of malaria cases occur in mountain worker populations. Using the behavioral change communication (BCC) strategy, an interventional study was conducted to promote mountain worker malaria prevention at a test site. This study found the methods and measures that are suitable for malaria prevention among mountain worker populations. During the Plasmodium falciparum elimination stage in Hainan, a representative sampling method was used to establish testing and control sites in areas of Hainan that were both affected by malaria and had a relatively high density of mountain workers. Two different methods were used: a BCC strategy and a conventional strategy as a control. Before and after the intervention, house visits, core group discussions, and structural surveys were utilized to collect qualitative and quantitative data regarding mountain worker populations (including knowledge, attitudes, and practices [KAPs]; infection status; and serological data), and these data from the testing and control areas were compared to evaluate the effectiveness of BCC strategies in the prevention of malaria. In the BCC malaria prevention strategy testing areas, the accuracy rates of malaria-related KAP were significantly improved among mountain worker populations. The accuracy rates in the 3 aspects of malaria-related KAP increased from 37.73%, 37.00%, and 43.04% to 89.01%, 91.53%, and 92.25%, respectively. The changes in all 3 aspects of KAP were statistically significant (p < 0.01). In the control sites, the changes in the indices were not as marked as in the testing areas, and the change was not statistically significant (p > 0.05). Furthermore, in the testing areas, both the percentage testing positive in the serum malaria indirect fluorescent antibody test (IFAT) and the number of people inflicted decreased more significantly than in the control sites (p < 0.01). The use of the BCC strategy significantly improved the ability of mountain workers in Hainan to avoid malarial infection. Educational and promotional materials and measures were developed and selected in the process, and hands-on experience was gained that will help achieve the goal of total malaria elimination in Hainan.

Modeling the Cost Effectiveness of Malaria Control Interventions in the Highlands of Western Kenya

PubMed Central

Stuckey, Erin M.; Stevenson, Jennifer; Galactionova, Katya; Baidjoe, Amrish Y.; Bousema, Teun; Odongo, Wycliffe; Kariuki, Simon; Drakeley, Chris; Smith, Thomas A.; Cox, Jonathan; Chitnis, Nakul

2014-01-01

Introduction Tools that allow for in silico optimization of available malaria control strategies can assist the decision-making process for prioritizing interventions. The OpenMalaria stochastic simulation modeling platform can be applied to simulate the impact of interventions singly and in combination as implemented in Rachuonyo South District, western Kenya, to support this goal. Methods Combinations of malaria interventions were simulated using a previously-published, validated model of malaria epidemiology and control in the study area. An economic model of the costs of case management and malaria control interventions in Kenya was applied to simulation results and cost-effectiveness of each intervention combination compared to the corresponding simulated outputs of a scenario without interventions. Uncertainty was evaluated by varying health system and intervention delivery parameters. Results The intervention strategy with the greatest simulated health impact employed long lasting insecticide treated net (LLIN) use by 80% of the population, 90% of households covered by indoor residual spraying (IRS) with deployment starting in April, and intermittent screen and treat (IST) of school children using Artemether lumefantrine (AL) with 80% coverage twice per term. However, the current malaria control strategy in the study area including LLIN use of 56% and IRS coverage of 70% was the most cost effective at reducing disability-adjusted life years (DALYs) over a five year period. Conclusions All the simulated intervention combinations can be considered cost effective in the context of available resources for health in Kenya. Increasing coverage of vector control interventions has a larger simulated impact compared to adding IST to the current implementation strategy, suggesting that transmission in the study area is not at a level to warrant replacing vector control to a school-based screen and treat program. These results have the potential to assist malaria control program managers in the study area in adding new or changing implementation of current interventions. PMID:25290939

Modeling the cost effectiveness of malaria control interventions in the highlands of western Kenya.

PubMed

Stuckey, Erin M; Stevenson, Jennifer; Galactionova, Katya; Baidjoe, Amrish Y; Bousema, Teun; Odongo, Wycliffe; Kariuki, Simon; Drakeley, Chris; Smith, Thomas A; Cox, Jonathan; Chitnis, Nakul

2014-01-01

Tools that allow for in silico optimization of available malaria control strategies can assist the decision-making process for prioritizing interventions. The OpenMalaria stochastic simulation modeling platform can be applied to simulate the impact of interventions singly and in combination as implemented in Rachuonyo South District, western Kenya, to support this goal. Combinations of malaria interventions were simulated using a previously-published, validated model of malaria epidemiology and control in the study area. An economic model of the costs of case management and malaria control interventions in Kenya was applied to simulation results and cost-effectiveness of each intervention combination compared to the corresponding simulated outputs of a scenario without interventions. Uncertainty was evaluated by varying health system and intervention delivery parameters. The intervention strategy with the greatest simulated health impact employed long lasting insecticide treated net (LLIN) use by 80% of the population, 90% of households covered by indoor residual spraying (IRS) with deployment starting in April, and intermittent screen and treat (IST) of school children using Artemether lumefantrine (AL) with 80% coverage twice per term. However, the current malaria control strategy in the study area including LLIN use of 56% and IRS coverage of 70% was the most cost effective at reducing disability-adjusted life years (DALYs) over a five year period. All the simulated intervention combinations can be considered cost effective in the context of available resources for health in Kenya. Increasing coverage of vector control interventions has a larger simulated impact compared to adding IST to the current implementation strategy, suggesting that transmission in the study area is not at a level to warrant replacing vector control to a school-based screen and treat program. These results have the potential to assist malaria control program managers in the study area in adding new or changing implementation of current interventions.

The past, present and future use of epidemiological intelligence to plan malaria vector control and parasite prevention in Uganda.

PubMed

Talisuna, Ambrose O; Noor, Abdisalan M; Okui, Albert P; Snow, Robert W

2015-04-15

An important prelude to developing strategies to control infectious diseases is a detailed epidemiological evidence platform to target cost-effective interventions and define resource needs. A review of published and un-published reports of malaria vector control and parasite prevention in Uganda was conducted for the period 1900-2013. The objective was to provide a perspective as to how epidemiological intelligence was used to design malaria control before and during the global malaria eradication programme (GMEP) and to contrast this with the evidence generated in support of the Roll Back Malaria (RBM) initiative from 1998 to date. During the GMEP era, comprehensive investigations were undertaken on the effectiveness of vector and parasite control such as indoor residual house-spraying (IRS) and mass drug administration (MDA) at different sites in Uganda. Nationwide malariometric surveys were undertaken between 1964 and 1967 to provide a profile of risk, epidemiology and seasonality leading to an evidence-based national cartography of risk to characterize the diversity of malaria transmission in Uganda. At the launch of the RBM initiative in the late 1990s, an equivalent level of evidence was lacking. There was no contemporary national evidence-base for the likely impact of insecticide-treated nets (ITN), no new malariometric data, no new national cartography of malaria risk or any evidence of tailored intervention delivery based on variations in the ecology of malaria risk in Uganda. Despite millions of dollars of overseas development assistance over the last ten years in ITN, and more recently the resurrection of the use of IRS, the epidemiological impact of vector control remains uncertain due to an absence of nationwide basic parasite and vector-based field studies. Readily available epidemiological data should become the future business model to maximize malaria funding from 2015. Over the next five to ten years, accountability, impact analysis, financial business cases supported by a culture of data use should become the new paradigm by which malaria programmes, governments and their development partners operate.

Prospects for malaria elimination in non-Amazonian regions of Latin America.

PubMed

Herrera, Sócrates; Quiñones, Martha Lucia; Quintero, Juan Pablo; Corredor, Vladimir; Fuller, Douglas O; Mateus, Julio Cesar; Calzada, Jose E; Gutierrez, Juan B; Llanos, Alejandro; Soto, Edison; Menendez, Clara; Wu, Yimin; Alonso, Pedro; Carrasquilla, Gabriel; Galinski, Mary; Beier, John C; Arévalo-Herrera, Myriam

2012-03-01

Latin America contributes 1-1.2 million clinical malaria cases to the global malaria burden of about 300 million per year. In 21 malaria endemic countries, the population at risk in this region represents less than 10% of the total population exposed worldwide. Factors such as rapid deforestation, inadequate agricultural practices, climate change, political instability, and both increasing parasite drug resistance and vector resistance to insecticides contribute to malaria transmission. Recently, several malaria endemic countries have experienced a significant reduction in numbers of malaria cases. This is most likely due to actions taken by National Malaria Control Programs (NMCP) with the support from international funding agencies. We describe here the research strategies and activities to be undertaken by the Centro Latino Americano de Investigación en Malaria (CLAIM), a new research center established for the non-Amazonian region of Latin America by the National Institute of Allergy and Infectious Diseases (NIAID). Throughout a network of countries in the region, initially including Colombia, Guatemala, Panama, and Peru, CLAIM will address major gaps in our understanding of changing malaria epidemiology, vector biology and control, and clinical malaria mainly due to Plasmodium vivax. In close partnership with NMCPs, CLAIM seeks to conduct research on how and why malaria is decreasing in many countries of the region as a basis for developing and implementing new strategies that will accelerate malaria elimination. Copyright © 2011 Elsevier B.V. All rights reserved.

Knowledge of prevention, cause, symptom and practices of malaria among women in Burkina Faso.

PubMed

Yaya, Sanni; Bishwajit, Ghose; Ekholuenetale, Michael; Shah, Vaibhav; Kadio, Bernard; Udenigwe, Ogochukwu

2017-01-01

Malaria remains a major public health issue in most southern African countries as the disease remains hyper endemic. Burkina Faso continues to face challenges in the treatment of malaria, as the utilization of preventive measures remains low on a national scale. While it has been acknowledged that understanding women's health-seeking behaviours, perception of malaria and its preventive measures will aid in the control of malaria, there is paucity of information on Knowledge, Attitudes and Practices among women in the reproductive age of 15-49 years in Burkina Faso. This study investigated women's knowledge of malaria, attitudes towards malaria, and practices of malaria control in order to create a synergy between community efforts and governmental/non-governmental malaria control interventions in Burkina Faso. The analysis used data from the 2014 Burkina Faso Malaria Indicator Survey (MIS). In total 8111 women aged between 15-49 years were included in the present study. We assessed women's knowledge about 1) preventive measures, 2) causes and 3) symptoms of malaria, as well as malaria prevention practices for their children and during pregnancy. The socio-demographic characteristics were considered for Age, Religion, Education, Wealth index, Number of household members, Sex of household head, Household possession of radio, TV and Received antenatal care. Data were analyzed using STATA, version 14. Associations between variables were tested using a Chi-square and logistic regression, with the level of statistical significance set at 95%. A preponderant proportion of respondents were aged 15-29 years (mean age was 28.63±9.41). About three-quarters of the respondents had no formal education. An estimated two-third of the participants were of Islamic faith, while access to media and behavioural communication were generally poor. The level of knowledge was 53% for rural women and 68.2% for urban dwellers. In sum, there was 56.1% level of accurate knowledge of malaria among women in Burkina Faso. In the multivariable logistic regression, women in rural location had 40% reduction in the odds of having accurate knowledge of malaria when compared to urban women (aOR = 0.60; 95%CI: 0.52-0.68). The educational level was a key factor in the knowledge of malaria. The odds of having accurate knowledge of malaria increased as the educational level increased, hence, women with secondary and higher education had 29% and 93% increase in the odds of having accurate knowledge of malaria when compared to the women without formal education. Results indicate that antenatal care (ANC) services were major sources of information on malaria. Women who reportedly received ANC were 3.9 times more likely to have accurate knowledge of malaria when compared to those who did not utilize skilled ANC services (aOR = 3.90; 95%CI = 3.34-4.56). The overall knowledge of malaria prevention practices among a large proportion of women was found to be low, which implies that the knowledge about the prevention of malaria should be improved upon by both urban and rural dwellers. There is need for concerted behavioural communication intervention to improve the knowledge of malaria especially for rural dwellers regarding malaria prevention measures, causes and symptoms. Consistent efforts at providing relevant information by health organizations are needed to reduce and control incidences of malaria in the general public.

The Anopheles gambiae 2La chromosome inversion is associated with susceptibility to Plasmodium falciparum in Africa

PubMed Central

Riehle, Michelle M; Bukhari, Tullu; Gneme, Awa; Guelbeogo, Wamdaogo M; Coulibaly, Boubacar; Fofana, Abdrahamane; Pain, Adrien; Bischoff, Emmanuel; Renaud, Francois; Beavogui, Abdoul H; Traore, Sekou F; Sagnon, N’Fale; Vernick, Kenneth D

2017-01-01

Chromosome inversions suppress genetic recombination and establish co-adapted gene complexes, or supergenes. The 2La inversion is a widespread polymorphism in the Anopheles gambiae species complex, the major African mosquito vectors of human malaria. Here we show that alleles of the 2La inversion are associated with natural malaria infection levels in wild-captured vectors from West and East Africa. Mosquitoes carrying the more-susceptible allele (2L+a) are also behaviorally less likely to be found inside houses. Vector control tools that target indoor-resting mosquitoes, such as bednets and insecticides, are currently the cornerstone of malaria control in Africa. Populations with high levels of the 2L+a allele may form reservoirs of persistent outdoor malaria transmission requiring novel measures for surveillance and control. The 2La inversion is a major and previously unappreciated component of the natural malaria transmission system in Africa, influencing both malaria susceptibility and vector behavior. DOI: http://dx.doi.org/10.7554/eLife.25813.001 PMID:28643631

The Anopheles gambiae 2La chromosome inversion is associated with susceptibility to Plasmodium falciparum in Africa.

PubMed

Riehle, Michelle M; Bukhari, Tullu; Gneme, Awa; Guelbeogo, Wamdaogo M; Coulibaly, Boubacar; Fofana, Abdrahamane; Pain, Adrien; Bischoff, Emmanuel; Renaud, Francois; Beavogui, Abdoul H; Traore, Sekou F; Sagnon, N'Fale; Vernick, Kenneth D

2017-06-23

Chromosome inversions suppress genetic recombination and establish co-adapted gene complexes, or supergenes. The 2La inversion is a widespread polymorphism in the Anopheles gambiae species complex, the major African mosquito vectors of human malaria. Here we show that alleles of the 2La inversion are associated with natural malaria infection levels in wild-captured vectors from West and East Africa. Mosquitoes carrying the more-susceptible allele (2L+ a ) are also behaviorally less likely to be found inside houses. Vector control tools that target indoor-resting mosquitoes, such as bednets and insecticides, are currently the cornerstone of malaria control in Africa. Populations with high levels of the 2L+ a allele may form reservoirs of persistent outdoor malaria transmission requiring novel measures for surveillance and control. The 2La inversion is a major and previously unappreciated component of the natural malaria transmission system in Africa, influencing both malaria susceptibility and vector behavior.

Malaria in gold-mining areas in Colombia

PubMed Central

Castellanos, Angélica; Chaparro-Narváez, Pablo; Morales-Plaza, Cristhian David; Alzate, Alberto; Padilla, Julio; Arévalo, Myriam; Herrera, Sócrates

2016-01-01

Gold-mining may play an important role in the maintenance of malaria worldwide. Gold-mining, mostly illegal, has significantly expanded in Colombia during the last decade in areas with limited health care and disease prevention. We report a descriptive study that was carried out to determine the malaria prevalence in gold-mining areas of Colombia, using data from the public health surveillance system (National Health Institute) during the period 2010-2013. Gold-mining was more prevalent in the departments of Antioquia, Córdoba, Bolívar, Chocó, Nariño, Cauca, and Valle, which contributed 89.3% (270,753 cases) of the national malaria incidence from 2010-2013 and 31.6% of malaria cases were from mining areas. Mining regions, such as El Bagre, Zaragoza, and Segovia, in Antioquia, Puerto Libertador and Montelíbano, in Córdoba, and Buenaventura, in Valle del Cauca, were the most endemic areas. The annual parasite index (API) correlated with gold production (R2 0.82, p < 0.0001); for every 100 kg of gold produced, the API increased by 0.54 cases per 1,000 inhabitants. Lack of malaria control activities, together with high migration and proliferation of mosquito breeding sites, contribute to malaria in gold-mining regions. Specific control activities must be introduced to control this significant source of malaria in Colombia. PMID:26814645

Malaria in gold-mining areas in Colombia.

PubMed

Castellanos, Angélica; Chaparro-Narváez, Pablo; Morales-Plaza, Cristhian David; Alzate, Alberto; Padilla, Julio; Arévalo, Myriam; Herrera, Sócrates

2016-01-01

Gold-mining may play an important role in the maintenance of malaria worldwide. Gold-mining, mostly illegal, has significantly expanded in Colombia during the last decade in areas with limited health care and disease prevention. We report a descriptive study that was carried out to determine the malaria prevalence in gold-mining areas of Colombia, using data from the public health surveillance system (National Health Institute) during the period 2010-2013. Gold-mining was more prevalent in the departments of Antioquia, Córdoba, Bolívar, Chocó, Nariño, Cauca, and Valle, which contributed 89.3% (270,753 cases) of the national malaria incidence from 2010-2013 and 31.6% of malaria cases were from mining areas. Mining regions, such as El Bagre, Zaragoza, and Segovia, in Antioquia, Puerto Libertador and Montelíbano, in Córdoba, and Buenaventura, in Valle del Cauca, were the most endemic areas. The annual parasite index (API) correlated with gold production (R2 0.82, p < 0.0001); for every 100 kg of gold produced, the API increased by 0.54 cases per 1,000 inhabitants. Lack of malaria control activities, together with high migration and proliferation of mosquito breeding sites, contribute to malaria in gold-mining regions. Specific control activities must be introduced to control this significant source of malaria in Colombia.

Hydrological and geomorphological controls of malaria transmission

NASA Astrophysics Data System (ADS)

Smith, M. W.; Macklin, M. G.; Thomas, C. J.

2013-01-01

Malaria risk is linked inextricably to the hydrological and geomorphological processes that form vector breeding sites. Yet environmental controls of malaria transmission are often represented by temperature and rainfall amounts, ignoring hydrological and geomorphological influences altogether. Continental-scale studies incorporate hydrology implicitly through simple minimum rainfall thresholds, while community-scale coupled hydrological and entomological models do not represent the actual diversity of the mosquito vector breeding sites. The greatest range of malaria transmission responses to environmental factors is observed at the catchment scale where seemingly contradictory associations between rainfall and malaria risk can be explained by hydrological and geomorphological processes that govern surface water body formation and persistence. This paper extends recent efforts to incorporate ecological factors into malaria-risk models, proposing that the same detailed representation be afforded to hydrological and, at longer timescales relevant for predictions of climate change impacts, geomorphological processes. We review existing representations of environmental controls of malaria and identify a range of hydrologically distinct vector breeding sites from existing literature. We illustrate the potential complexity of interactions among hydrology, geomorphology and vector breeding sites by classifying a range of water bodies observed in a catchment in East Africa. Crucially, the mechanisms driving surface water body formation and destruction must be considered explicitly if we are to produce dynamic spatial models of malaria risk at catchment scales.

Nitric Oxide-Dependent Endothelial Dysfunction and Reduced Arginine Bioavailability in Plasmodium vivax Malaria but No Greater Increase in Intravascular Hemolysis in Severe Disease.

PubMed

Barber, Bridget E; William, Timothy; Grigg, Matthew J; Piera, Kim A; Chen, Youwei; Wang, Hao; Weinberg, J Brice; Yeo, Tsin W; Anstey, Nicholas M

2016-11-15

 Pathogenesis of severe Plasmodium vivax malaria is poorly understood. Endothelial dysfunction and reduced nitric oxide (NO) bioavailability characterize severe falciparum malaria, but have not been assessed in severe vivax malaria.  In patients with severe vivax malaria (n = 9), patients with nonsevere vivax malaria (n = 58), and healthy controls (n = 79), we measured NO-dependent endothelial function by using reactive hyperemia-peripheral arterial tonometry (RH-PAT) and assessed associations with arginine, asymmetric dimethylarginine (ADMA), and hemolysis.  The L-arginine level and the L-arginine to ADMA ratio (a measure of L-arginine bioavailability) were reduced in patients with severe vivax malaria and those with nonsevere vivax malaria, compared with healthy controls (median L-arginine level, 65, 66, and 98 µmol/mL, respectively [P = .0001]; median L-arginine to ADMA ratio, 115, 125, and 187, respectively [P = .0001]). Endothelial function was impaired in proportion to disease severity (median RH-PAT index, 1.49, 1.73, and 1.97 in patients with severe vivax malaria, those with nonsevere vivax malaria, and healthy controls, respectively; P = .018) and was associated with the L-arginine to ADMA ratio. While the posttreatment fall in hemoglobin level was greater in severe vivax malaria as compared to nonsevere vivax malaria (2.5 vs 1 g/dL; P = .0001), markers of intravascular hemolysis were not higher in severe disease.  Endothelial function is impaired in nonsevere and severe vivax malaria, is associated with reduced L-arginine bioavailability, and may contribute to microvascular pathogenesis. Severe disease appears to be more associated with extravascular hemolysis than with intravascular hemolysis. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

A qualitative study on health workers' and community members' perceived sources, role of information and communication on malaria treatment, prevention and control in southeast Nigeria.

PubMed

Umeano-Enemuoh, Jane C; Uzochukwu, Benjamim; Ezumah, Nkoli; Mangham-Jefferies, Lindsay; Wiseman, Virginia; Onwujekwe, Obinna

2015-10-22

It has been widely acknowledged that well-planned and executed communication programmes can contribute to achieving malaria prevention and treatment goals. This however requires a good understanding of current sources and roles of information used by both health workers and communities. The study aimed at determining health workers' and community members' sources, value and use of information on malaria prevention and treatment in Nigeria. Qualitative data was collected from six selected communities (three urban and three rural) in Enugu state, southeast Nigeria. A total of 18 Focus Group Discussions (FGDs) with 179 community members and 26 in-depth interviews (IDIs) with health workers in public and private health facilities were used to collect data on where people receive treatment for malaria and access information on malaria. The FGDS and IDIs also provided data on the values, uses and effects of information and communication on malaria treatment seeking and provision of services. The findings revealed that the major sources of information on malaria for health workers and community members were advertisements in the mass media, workshops and seminars organized by donor agencies, facility supervision, posters, other health workers, television and radio adverts. Community involvement in the design and delivery of information on malaria control was seen as a strong strategy for improving both consumer and provider knowledge. Information from the different sources catalyzed appropriate provision and consumption of malaria treatment amongst health workers and community members. Health workers and consumers receive information on malaria prevention and treatment from multiple sources of communication and information, which they find useful. Harnessing these information sources to encourage consistent and accurate messages around malaria prevention and treatment is a necessary first step in the design and implementation of malaria communication and behaviour change interventions and ultimately for the sustained control of malaria.

Major decline in malaria morbidity and mortality in the Union of Comoros between 2010 and 2014: The effect of a combination of prevention and control measures.

PubMed

Kassim, Said Abasse; James, Peter Bai; Alolga, Rachel Nammahime; Assanhou, Assogba Gabin; Kassim, Said Mohamed; Bacar, Anfane; Silai, Rahamatou; Tian, Lei; Li, Hongchao; Ma, Aixia

2016-06-17

Malaria remains a public health challenge in sub-Saharan Africa. In response to this, many countries are working towards achieving the World Health Assembly and Roll Back Malaria Partnership target of a 75% decline in malaria incidence. To assess trends in malaria morbidity and mortality in the three islands of the Comoros Archipelago from 2010 to 2014. This was a retrospective study in which all confirmed malaria cases and deaths recorded between 2010 and 2014 were accessed from the national malaria control database. Trends and comparisons in malaria incidence and case fatality rates for all age groups, including under-5 children and pregnant women, were analysed using Microsoft Excel and SPSS version 16. A substantial decline in malaria incidence was observed for each island between 2010 and 2014; from 75.98 cases per 1 000 population in 2010 to 0.14 in 2014 in Moheli, 60.60 to 0.02 in Anjouan and 235.36 to 5.47 in Grand Comoro. Additionally, a general reduction in malaria case fatalities was observed. In Moheli, there were no case fatalities between 2010 and 2014, while there was a decline in the case fatality rate in Anjouan (from 1.20 fatalities per 1 000 cases to 0) and Grand Comoros (0.51 to 0). There were also significant differences (p<0.05) in malaria incidence and case fatalities between the three islands. A similar trend was observed for pregnant women and under-5 children. Our study indicates a significant decline in malaria morbidity and mortality in the islands of Moheli, Anjouan and Grand Comoro from 2010 to 2014. This considerable reduction is attributed to a combination of malaria prevention and control interventions implemented during the study period.

A good night's sleep and the habit of net use: perceptions of risk and reasons for bed net use in Bukoba and Zanzibar.

PubMed

Koenker, Hannah M; Loll, Dana; Rweyemamu, Datius; Ali, Abdullah S

2013-06-13

Intensive malaria control interventions in the United Republic of Tanzania have contributed to reductions in malaria prevalence. Given that malaria control remains reliant upon continued use of long-lasting insecticidal bed nets (LLINs) even when the threat of malaria has been reduced, this qualitative study sought to understand how changes in perceived risk influence LLIN usage, and to explore in more detail the benefits of net use that are unrelated to malaria. Eleven focus group discussions were conducted in Bukoba Rural district and in Zanzibar Urban West district in late 2011. Participants were males aged 18 and over, females between the ages of 18 and 49, and females at least 50 years old. The perceived risk of malaria had decreased among the respondents, and malaria control interventions were credited for the decline. Participants cited reductions in both the severity of malaria and in their perceived susceptibility to malaria. However, malaria was still considered a significant threat. Participants' conceptualization of risk appeared to be an important consideration for net use. At the same time, comfort and aspects of comfort (getting a good night's sleep, avoiding biting pests) appeared to play a large role in personal decisions to use nets consistently or not. Barriers to comfort (feeling uncomfortable or trapped; perceived difficulty breathing, or itching/rashes) were frequently cited as reasons not to use a net consistently. While it was apparent that participants acknowledged the malaria-prevention benefits of net use, the exploration of the risk and comfort determinants of net use provides a richer understanding of net use behaviours, particularly in a setting where transmission has fallen and yet consistent net use is still crucial to maintaining those gains. Future behaviour change communication campaigns should capitalize on the non-malaria benefits of net use that provide a long-term rationale for consistent use even when the immediate threat of malaria transmission has been reduced.

The role of ENSO in understanding changes in Colombia's annual malaria burden by region, 1960–2006

PubMed Central

Mantilla, Gilma; Oliveros, Hugo; Barnston, Anthony G

2009-01-01

Background Malaria remains a serious problem in Colombia. The number of malaria cases is governed by multiple climatic and non-climatic factors. Malaria control policies, and climate controls such as rainfall and temperature variations associated with the El Niño/Southern Oscillation (ENSO), have been associated with malaria case numbers. Using historical climate data and annual malaria case number data from 1960 to 2006, statistical models are developed to isolate the effects of climate in each of Colombia's five contrasting geographical regions. Methods Because year to year climate variability associated with ENSO causes interannual variability in malaria case numbers, while changes in population and institutional control policy result in more gradual trends, the chosen predictors in the models are annual indices of the ENSO state (sea surface temperature [SST] in the tropical Pacific Ocean) and time reference indices keyed to two major malaria trends during the study period. Two models were used: a Poisson and a Negative Binomial regression model. Two ENSO indices, two time reference indices, and one dummy variable are chosen as candidate predictors. The analysis was conducted using the five geographical regions to match the similar aggregation used by the National Institute of Health for its official reports. Results The Negative Binomial regression model is found better suited to the malaria cases in Colombia. Both the trend variables and the ENSO measures are significant predictors of malaria case numbers in Colombia as a whole, and in two of the five regions. A one degree Celsius change in SST (indicating a weak to moderate ENSO event) is seen to translate to an approximate 20% increase in malaria cases, holding other variables constant. Conclusion Regional differentiation in the role of ENSO in understanding changes in Colombia's annual malaria burden during 1960–2006 was found, constituting a new approach to use ENSO as a significant predictor of the malaria cases in Colombia. These results naturally point to additional needed work: (1) refining the regional and seasonal dependence of climate on the ENSO state, and of malaria on the climate variables; (2) incorporating ENSO-related climate variability into dynamic malaria models. PMID:19133152

Malaria-related knowledge and prevention practices in four neighbourhoods in and around Mumbai, India: a cross-sectional study.

PubMed

Dhawan, Gaurav; Joseph, Nidhin; Pekow, Penelope S; Rogers, Christine A; Poudel, Krishna C; Bulzacchelli, Maria T

2014-08-07

India accounts for the highest number of malaria cases outside of Africa. Eighty per cent of India's population lives in malaria-risk areas, with cases increasing in urban areas. Mumbai, India, one of the most populous cities in the world, has experienced such an increase. To be successful, many malaria control efforts require community participation, which in turn depends on individuals' knowledge and awareness of the disease. This study assessed the knowledge and prevention practices regarding malaria in residents of four different areas of Mumbai, India, around the time of a malaria outbreak and the start of a widespread awareness campaign. A cross-sectional comparative study assessed malaria-related knowledge and prevention practices in four geographically and socio-demographically distinct areas of Mumbai, India. A structured interviewer-administered questionnaire was administered to a stratified random sample of 119 households between 16 December 2010 and 30 January 2011. Participant socio-demographic characteristics, malaria knowledge, malaria prevention practices, and household environmental factors were examined overall and compared across the four areas of Mumbai. Overall, respondents had excellent knowledge of the mosquito as the means of transmission of malaria, mosquito biting times and breeding sites, and fever as a symptom of malaria. However, many respondents also held misconceptions about malaria transmission and symptoms. Respondents generally knew that bed nets are an effective prevention strategy, but only 30% used them, and only 4% used insecticide-treated bed nets. Knowledge and prevention practices varied across the four areas of Mumbai. Although most residents know that bed nets are effective in preventing malaria, usage of bed nets is very low, and almost no residents use insecticide-treated bed nets. As the four areas of Mumbai differed in knowledge, prevention practices, and primary sources of information, malaria control campaigns should be tailored according to the knowledge gaps, practices, environments, resources, and preferences in different areas of the city, using the interpersonal and media channels most likely to reach the target audiences. Malaria control efforts involving bed nets should emphasize use of insecticide-treated bed nets.

Impact of Artemisinin-Based Combination Therapy and Insecticide-Treated Nets on Malaria Burden in Zanzibar

PubMed Central

Bhattarai, Achuyt; Ali, Abdullah S; Kachur, S. Patrick; Mårtensson, Andreas; Abbas, Ali K; Khatib, Rashid; Al-mafazy, Abdul-wahiyd; Ramsan, Mahdi; Rotllant, Guida; Gerstenmaier, Jan F; Molteni, Fabrizio; Abdulla, Salim; Montgomery, Scott M; Kaneko, Akira; Björkman, Anders

2007-01-01

Background The Roll Back Malaria strategy recommends a combination of interventions for malaria control. Zanzibar implemented artemisinin-based combination therapy (ACT) for uncomplicated malaria in late 2003 and long-lasting insecticidal nets (LLINs) from early 2006. ACT is provided free of charge to all malaria patients, while LLINs are distributed free to children under age 5 y (“under five”) and pregnant women. We investigated temporal trends in Plasmodium falciparum prevalence and malaria-related health parameters following the implementation of these two malaria control interventions in Zanzibar. Methods and Findings Cross-sectional clinical and parasitological surveys in children under the age of 14 y were conducted in North A District in May 2003, 2005, and 2006. Survey data were analyzed in a logistic regression model and adjusted for complex sampling design and potential confounders. Records from all 13 public health facilities in North A District were analyzed for malaria-related outpatient visits and admissions. Mortality and demographic data were obtained from District Commissioner's Office. P. falciparum prevalence decreased in children under five between 2003 and 2006; using 2003 as the reference year, odds ratios (ORs) and 95% confidence intervals (CIs) were, for 2005, 0.55 (0.28–1.08), and for 2006, 0.03 (0.00–0.27); p for trend < 0.001. Between 2002 and 2005 crude under-five, infant (under age 1 y), and child (aged 1–4 y) mortality decreased by 52%, 33%, and 71%, respectively. Similarly, malaria-related admissions, blood transfusions, and malaria-attributed mortality decreased significantly by 77%, 67% and 75%, respectively, between 2002 and 2005 in children under five. Climatic conditions favorable for malaria transmission persisted throughout the observational period. Conclusions Following deployment of ACT in Zanzibar 2003, malaria-associated morbidity and mortality decreased dramatically within two years. Additional distribution of LLINs in early 2006 resulted in a 10-fold reduction of malaria parasite prevalence. The results indicate that the Millennium Development Goals of reducing mortality in children under five and alleviating the burden of malaria are achievable in tropical Africa with high coverage of combined malaria control interventions. PMID:17988171

Malaria in East African highlands during the past 30 years: impact of environmental changes

PubMed Central

Himeidan, Yousif E.; Kweka, Eliningaya J.

2012-01-01

East African highlands are one of the most populated regions in Africa. The population densities in the highlands ranged between 158 persons/km2 in Ethiopia and 410 persons/km2 in Rwanda. According to the United Nations Population Fund, the region has the world's highest population growth rate. These factors are likely behind the high rates of poverty among the populations. As there were no employment opportunities other than agricultural, this demographic pressure of poor populations have included in an extensive unprecedented land use and land cover changes such as modification of bushland, woodland, and grassland on hillsides to farmland and transformation of papyrus swamps in valley bottoms to dairy pastures and cropland and changing of fallows on hillsides from short or seasonal to longer or perennial. Areas harvested for food crops were therefore increased by more than 100% in most of the highlands. The lost of forest areas, mainly due to subsistence agriculture, between 1990 and 2010 ranged between 8000 ha in Rwanda and 2,838,000 ha in Ethiopia. These unmitigated environmental changes in the highlands led to rise temperature and optimizing the spread and survival of malaria vectors and development of malaria parasites. Malaria in highlands was initially governed by low ambient temperature, trend of malaria transmission was therefore increased and several epidemics were observed in late 1980s and early 2000s. Although, malaria is decreasing through intensified interventions since mid 2000s onwards, these environmental changes might expose population in the highlands of east Africa to an increase risk of malaria and its epidemic particularly if the current interventions are not sustained. PMID:22934065

Role of geospatial technology in identifying natural habitat of malarial vectors in South Andaman, India.

PubMed

Shankar, Shiva; Agrawal, Deepak Kumar

2016-03-01

Malaria is a serious disease which has repeatedly threatened Andaman, an island territory of India. Uncharted dense vegetation and inaccessibility are the salient features of the area and the major areas are covered by remotely sensed data to identify the malaria vector's natural habitat. The present investigation appraises the role of geospatial technologies in identifying the natural habitat of malarial vectors. The base map was prepared from Survey of India's toposheets, the landuse map was prepared from indices techniques like normalised difference vegetation index (NDVI), normalised difference water index (NDWI), modified normalised difference water index (MNDWI), normalised difference pond index (NDPI), and normalized difference turbidity index (NDTI) in conjugation with visual interpretation. The soil moisture content map was reproduced from the soil atlas of Andaman and Nicobar Islands followed by generation of an aspect profile from ASTER-GDEM satellite data. Both the landuse map and aspect profile were validated for accuracy in the field. A weighted overlay analysis of the classes like landuse, soil moisture and aspect profile of the study area resulted in identification of the potential natural habitat map of malaria vector surrounding the areas of Tushnabad, Garacharma, Manglutan, Chouldari, Ferrargunj and Wimberlygunj hamlets. The natural habitat of malaria vector indicated that Tushnabad, Garacharma, Manglutan, Chouldari, Ferrargunj and Wimberlygunj hamlets are within the proximity of 2.5 km from the prime habitat location with more number of malaria positive cases. Also these hamlets are surrounded by dense evergreen forest and the land surface is draped by clay loam and clay soil texture exhibiting high soil moisture content warranting high rates of survival and proliferation of the vector ensuring resurgence of malaria every year. It is thus concluded that application of geospatial technologies plays an important role in identifying the natural habitat of malaria vector.

[History of malaria control in the French armed forces: from Algeria to the Macedonian front during the first World War].

PubMed

Migliani, R; Meynard, J-B; Milleliri, J-M; Verret, C; Rapp, C

2014-01-01

The French joint military health corps has long experience in malaria control. Many military physicians played an essential role in the 19th century: Maillot revolutionized malaria treatment by using quinine during the conquest of Algeria, and Laveran discovered the causal parasite (the genus Plasmodium) there. This experience continued under the direction of Laveran and the Sergent brothers on the eastern front in Greek Macedonia during World War I. The vast coordinated control plan established on this front from 1917 delivered the French infantrymen from malaria and led to victory over the Bulgarian forces, which capitulated in September 1918.

The effect of household heads training about the use of treated bed nets on the burden of malaria and anaemia in under-five children: a cluster randomized trial in Ethiopia.

PubMed

Deribew, Amare; Birhanu, Zewdie; Sena, Lelisa; Dejene, Tariku; Reda, Ayalu A; Sudhakar, Morankar; Alemseged, Fessehaye; Tessema, Fasil; Zeynudin, Ahmed; Biadgilign, Sibhatu; Deribe, Kebede

2012-01-06

Long-lasting insecticide-treated bed nets (LLITN) have demonstrated a significant effect in reducing malaria-related morbidity and mortality. However, barriers on the utilization of LLITN have hampered the desired outcomes. The aim of this study was to assess the effect of community empowerment on the burden of malaria and anaemia in under-five children in Ethiopia. A cluster randomized trial was done in 22 (11 intervention and 11 control) villages in south-west Ethiopia. The intervention consisted of tailored training of household heads about the proper use of LLITN and community network system. The burden of malaria and anaemia in under-five children was determined through mass blood investigation at baseline, six and 12 months of the project period. Cases of malaria and anaemia were treated based on the national protocol. The burden of malaria and anaemia between the intervention and control villages was compared using the complex logistic regression model by taking into account the clustering effect. Eight Focus group discussions were conducted to complement the quantitative findings. A total of 2,105 household heads received the intervention and the prevalence of malaria and anaemia was assessed among 2410, 2037 and 2612 under-five children at baseline, six and 12 months of the project period respectively. During the high transmission/epidemic season, children in the intervention arm were less likely to have malaria as compared to children in the control arm (OR = 0.42; 95%CI: 0.32, 0.57). Symptomatic malaria also steadily declined in the intervention villages compared to the control villages in the follow up periods. Children in the intervention arm were less likely to be anaemic compared to those in the control arm both at the high (OR = 0.84; 95%CI: 0.71, 0.99)) and low (OR = 0.73; 95%CI: 0.60, 0.89) transmission seasons. Training of household heads on the utilization of LLITN significantly reduces the burden of malaria in under-five children. The Ministry of Health of Ethiopia in collaboration with other partners should design similar strategies in high-risk areas to control malaria in Ethiopia. Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12610000035022.

Malaria Molecular Epidemiology: Lessons from the International Centers of Excellence for Malaria Research Network

PubMed Central

Escalante, Ananias A.; Ferreira, Marcelo U.; Vinetz, Joseph M.; Volkman, Sarah K.; Cui, Liwang; Gamboa, Dionicia; Krogstad, Donald J.; Barry, Alyssa E.; Carlton, Jane M.; van Eijk, Anna Maria; Pradhan, Khageswar; Mueller, Ivo; Greenhouse, Bryan; Andreina Pacheco, M.; Vallejo, Andres F.; Herrera, Socrates; Felger, Ingrid

2015-01-01

Molecular epidemiology leverages genetic information to study the risk factors that affect the frequency and distribution of malaria cases. This article describes molecular epidemiologic investigations currently being carried out by the International Centers of Excellence for Malaria Research (ICEMR) network in a variety of malaria-endemic settings. First, we discuss various novel approaches to understand malaria incidence and gametocytemia, focusing on Plasmodium falciparum and Plasmodium vivax. Second, we describe and compare different parasite genotyping methods commonly used in malaria epidemiology and population genetics. Finally, we discuss potential applications of molecular epidemiological tools and methods toward malaria control and elimination efforts. PMID:26259945

Ivermectin: a complimentary weapon against the spread of malaria?

PubMed Central

Alout, Haoues; Foy, Brian

2017-01-01

Introduction Ivermectin has transformed the treatment of parasitic diseases and led to incommensurable benefits to humans and animals. Ivermectin is effective in treating several neglected infectious diseases and recently it has been shown to reduce malaria parasite transmission. Areas covered Malaria control strategies could benefit from the addition of ivermectin to interrupt the transmission cycle if it is a long lasting formulation or repeatedly administered. In turn, this will help also to control neglected infectious diseases where the elimination goal has been slower to achieve. Despite the relevance of using ivermectin for integrated and sustained disease control, there are still essential questions that remain to be addressed about safety and practicality. The efficacy in various malaria ecologies and the interaction between control tools, either drugs or insecticides, are also important to assess. Expert commentary Overlapping distribution of several infectious diseases reveals the benefit of integrating control programs against several infectious diseases into one strategy for cost effectiveness and to reach the elimination goals. The use of ivermectin to control malaria transmission will necessitate development and testing of long-lasting formulations or repeated treatments, and implementation of these treatments with other disease control tools may increase the chance of successful and sustained control. PMID:27960597

Temporo-spatial distribution of insecticide-resistance in Indian malaria vectors in the last quarter-century: Need for regular resistance monitoring and management.

PubMed

Raghavendra, Kamaraju; Velamuri, Poonam Sharma; Verma, Vaishali; Elamathi, Natarajan; Barik, Tapan Kumar; Bhatt, Rajendra Mohan; Dash, Aditya Prasad

2017-01-01

The Indian vector control programme similar to other programmes in the world is still reliant on chemical insecticides. Anopheles culicifacies is the major vector out of six primary malaria vectors in India and alone contributes about 2/3 malaria cases annually; and per se its control is actually control of malaria in India. For effective management of vectors, current information on their susceptibility status to different insecticides is essential. In this review, an attempt was made to compile and present the available data on the susceptibility status of different malaria vector species in India from the last 2.5 decades. Literature search was conducted by different means mainly web and library search; susceptibility data was collated from 62 sources for the nine malaria vector species from 145 districts in 21 states and two union territories between 1991 and 2016. Interpretation of the susceptibility/resistance status was made on basis of the recent WHO criteria. Comprehensive analysis of the data indicated that An. culicifacies, a major vector species was resistant to at least one insecticide in 70% (101/145) of the districts. It was reported mostly resistant to DDT and malathion whereas, its resistant status against deltamethrin varied across the districts. The major threat for the malaria control programmes is multiple-insecticide-resistance in An. culicifacies which needs immediate attention for resistance management in order to sustain the gains achieved so far, as the programmes have targeted malaria elimination by 2030.

Radar Monitoring of Wetlands for Malaria Control

NASA Technical Reports Server (NTRS)

Pope, Kevin O.

1997-01-01

Malaria is the most important vector-borne tropical disease (Collins and Paskewitz, 1995) and there is no simple and universally applicable form of vector control. While new methods such as malaria vaccine or genetic manipulation of mosquitoes are being explored in the laboratories, the need for more field research on malaria transmission remains very strong. For the foreseeable future many malaria programs must focus on controlling the vector, the anopheline mosquito, often under the specter of shrinking budgets. Therefore information on which human populations are at the greatest risk is especially valuable when allocating scarce resources. The goal of the Radar Monitoring of Wetlands for Malaria Control Project is to demonstrate the feasibility of using Radarsat or other comparable satellite radar imaging systems to determine where and when human populations are at greatest risk for contracting malaria. The study area is northern Belize, a region with abundant wetlands and a potentially serious malaria problem. A key aspect of this study is the analysis of multi-temporal satellite imagery to track seasonal flooding of anopheline mosquito breeding sites. Radarsat images of the test site in Belize have been acquired one to three times a month over the last year, however,, to date only one processed image has been received from the Alaska SAR Facility for analysis. Therefore analysis at this stage is focussed on determining the radar backscatter characteristics of known anopheline breeding sites, with future work to be dedicated toward seasonal changes.

Equity and adequacy of international donor assistance for global malaria control: an analysis of populations at risk and external funding commitments

PubMed Central

Snow, Robert W; Okiro, Emelda A; Gething, Peter W; Atun, Rifat; Hay, Simon I

2010-01-01

Summary Background Financing for malaria control has increased as part of international commitments to achieve the Millennium Development Goals (MDGs). We aimed to identify the unmet financial needs that would be biologically and economically equitable and would increase the chances of reaching worldwide malaria-control ambitions. Methods Populations at risk of stable Plasmodium falciparum or Plasmodium vivax transmission were calculated for 2007 and 2009 for 93 malaria-endemic countries to measure biological need. National per-person gross domestic product (GDP) was used to define economic need. An analysis of external donor assistance for malaria control was done for the period 2002–09 to compute overall and annualised per-person at-risk-funding commitments. Annualised malaria donor assistance was compared with independent predictions of funding needed to reach international targets of 80% coverage of best practices in case-management and effective disease prevention. Countries were ranked in relation to biological, economic, and unmet needs to examine equity and adequacy of support by 2010. Findings International financing for malaria control has increased by 166% (from $0·73 billion to $1·94 billion) since 2007 and is broadly consistent with biological needs. African countries have become major recipients of external assistance; however, countries where P vivax continues to pose threats to control ambitions are not as well funded. 21 countries have reached adequate assistance to provide a comprehensive suite of interventions by 2009, including 12 countries in Africa. However, this assistance was inadequate for 50 countries representing 61% of the worldwide population at risk of malaria—including ten countries in Africa and five in Asia that coincidentally are some of the poorest countries. Approval of donor funding for malaria control does not correlate with GDP. Interpretation Funding for malaria control worldwide is 60% lower than the US$4·9 billion needed for comprehensive control in 2010; this includes funding shortfalls for a wide range of countries with different numbers of people at risk and different levels of domestic income. More efficient targeting of financial resources against biological need and national income should create a more equitable investment portfolio that with increased commitments will guarantee sustained financing of control in countries most at risk and least able to support themselves. Funding Wellcome Trust. PMID:20889199

Malaria entomological risk factors in relation to land cover in the Lower Caura River Basin, Venezuela

PubMed Central

Rubio-Palis, Yasmin; Bevilacqua, Mariapia; Medina, Domingo Alberto; Moreno, Jorge Ernesto; Cárdenas, Lya; Sánchez, Víctor; Estrada, Yarys; Anaya, William; Martínez, Ángela

2013-01-01

To explore the effects of deforestation and resulting differences in vegetation and land cover on entomological parameters, such as anopheline species composition, abundance, biting rate, parity and entomological inoculation rate (EIR), three villages were selected in the Lower Caura River Basin, state of Bolívar, Venezuela. All-night mosquito collections were conducted between March 2008-January 2009 using CDC light traps and Mosquito Magnet(r) Liberty Plus. Human landing catches were performed between 06:00 pm-10:00 pm, when anophelines were most active. Four types of vegetation were identified. The Annual Parasite Index was not correlated with the type of vegetation. The least abundantly forested village had the highest anopheline abundance, biting rate and species diversity. Anopheles darlingi and Anopheles nuneztovari were the most abundant species and were collected in all three villages. Both species showed unique biting cycles. The more abundantly forested village of El Palmar reported the highest EIR. The results confirmed previous observations that the impacts of deforestation and resulting changes in vegetation cover on malaria transmission are complex and vary locally. PMID:23579803

Malaria entomological risk factors in relation to land cover in the Lower Caura River Basin, Venezuela.

PubMed

Rubio-Palis, Yasmin; Bevilacqua, Mariapia; Medina, Domingo Alberto; Moreno, Jorge Ernesto; Cárdenas, Lya; Sánchez, Víctor; Estrada, Yarys; Anaya, William; Martínez, Ángela

2013-04-01

To explore the effects of deforestation and resulting differences in vegetation and land cover on entomological parameters, such as anopheline species composition, abundance, biting rate, parity and entomological inoculation rate (EIR), three villages were selected in the Lower Caura River Basin, state of Bolívar, Venezuela. All-night mosquito collections were conducted between March 2008-January 2009 using CDC light traps and Mosquito Magnet® Liberty Plus. Human landing catches were performed between 06:00 pm-10:00 pm, when anophelines were most active. Four types of vegetation were identified. The Annual Parasite Index was not correlated with the type of vegetation. The least abundantly forested village had the highest anopheline abundance, biting rate and species diversity. Anopheles darlingi and Anopheles nuneztovari were the most abundant species and were collected in all three villages. Both species showed unique biting cycles. The more abundantly forested village of El Palmar reported the highest EIR. The results confirmed previous observations that the impacts of deforestation and resulting changes in vegetation cover on malaria transmission are complex and vary locally.

The potential for fungal biopesticides to reduce malaria transmission under diverse environmental conditions.

PubMed

Heinig, R L; Paaijmans, Krijn P; Hancock, Penelope A; Thomas, Matthew B

2015-12-01

The effectiveness of conventional malaria vector control is being threatened by the spread of insecticide resistance. One promising alternative to chemicals is the use of naturally-occurring insect-killing fungi. Numerous laboratory studies have shown that isolates of fungal pathogens such as Beauveria bassiana can infect and kill adult mosquitoes, including those resistant to chemical insecticides.Unlike chemical insecticides, fungi may take up to a week or more to kill mosquitoes following exposure. This slow kill speed can still reduce malaria transmission because the malaria parasite itself takes at least eight days to complete its development within the mosquito. However, both fungal virulence and parasite development rate are strongly temperature-dependent, so it is possible that biopesticide efficacy could vary across different transmission environments.We examined the virulence of a candidate fungal isolate against two key malaria vectors at temperatures from 10-34 °C. Regardless of temperature, the fungus killed more than 90% of exposed mosquitoes within the predicted duration of the malarial extrinsic incubation period, a result that was robust to realistic diurnal temperature variation.We then incorporated temperature sensitivities of a suite of mosquito, parasite and fungus life-history traits that are important determinants of malaria transmission into a stage-structured malaria transmission model. The model predicted that, at achievable daily fungal infection rates, fungal biopesticides have the potential to deliver substantial reductions in the density of malaria-infectious mosquitoes across all temperatures representative of malaria transmission environments. Synthesis and applications . Our study combines empirical data and theoretical modelling to prospectively evaluate the potential of fungal biopesticides to control adult malaria vectors. Our results suggest that Beauveria bassiana could be a potent tool for malaria control and support further development of fungal biopesticides to manage infectious disease vectors.

Workshop report: Malaria vaccine development in Europe--preparing for the future.

PubMed

Viebig, Nicola K; D'Alessio, Flavia; Draper, Simon J; Sim, B Kim Lee; Mordmüller, Benjamin; Bowyer, Paul W; Luty, Adrian J F; Jungbluth, Stefan; Chitnis, Chetan E; Hill, Adrian V S; Kremsner, Peter; Craig, Alister G; Kocken, Clemens H M; Leroy, Odile

2015-11-17

The deployment of a safe and effective malaria vaccine will be an important tool for the control of malaria and the reduction in malaria deaths. With the launch of the 2030 Malaria Vaccine Technology Roadmap, the malaria community has updated the goals and priorities for the development of such a vaccine and is now paving the way for a second phase of malaria vaccine development. During a workshop in Brussels in November 2014, hosted by the European Vaccine Initiative, key players from the European, North American and African malaria vaccine community discussed European strategies for future malaria vaccine development in the global context. The recommendations of the European malaria community should guide researchers, policy makers and funders of global health research and development in fulfilling the ambitious goals set in the updated Malaria Vaccine Technology Roadmap. Copyright © 2015.

Optimal control analysis of malaria-schistosomiasis co-infection dynamics.

PubMed

Okosun, Kazeem Oare; Smith, Robert

2017-04-01

This paper presents a mathematical model for malaria--schistosomiasis co-infection in order to investigate their synergistic relationship in the presence of treatment. We first analyse the single infection steady states, then investigate the existence and stability of equilibria and then calculate the basic reproduction numbers. Both the single-infection models and the co-infection model exhibit backward bifurcations. We carrying out a sensitivity analysis of the co-infection model and show that schistosomiasis infection may not be associated with an increased risk of malaria. Conversely, malaria infection may be associated with an increased risk of schistosomiasis. Furthermore, we found that effective treatment and prevention of schistosomiasis infection would also assist in the effective control and eradication of malaria. Finally, we apply Pontryagin's Maximum Principle to the model in order to determine optimal strategies for control of both diseases.

Local prevalence and transmission of avian malaria in the Alakai Plateau of Kauai, Hawaii, U.S.A.

PubMed

Glad, Anouk; Crampton, Lisa H

2015-12-01

Avian malaria is among the most important threats to native Hawaiian forest birds. It is caused by the parasite Plasmodium relictum and is transmitted by the introduced mosquito vector Culex quinquefasciatus. Temperature increases and precipitation declines due to climate change over the last decade may be responsible for the observed recent expansion in the range and prevalence of avian malaria on the Alakai Plateau, Kauai Island. To examine the hypothesis that conditions are now favorable for transmission of malaria on the Plateau, mosquitoes were sampled with CO2 and Reiter oviposition traps at three sites (Kawaikoi, Halepa'akai, and Koke'e) on several occasions between October, 2013 and April, 2014. P. relictum infection was assessed by PCR or dissection under a microscope. We also surveyed mosquito larvae along Halepa'akai and Kawaikoi streams. We observed that Cx. quinquefasciatus is well established on the Alakai Plateau, as mosquitoes were caught on all field trips, except in April at Halepa'akai, and larvae were found throughout the year. We observed differences in adult abundance among sites and microhabitats (stream vs ridge lines). © 2015 The Society for Vector Ecology.

Exploiting the behaviour of wild malaria vectors to achieve high infection with fungal biocontrol agents

PubMed Central

2012-01-01

Background Control of mosquitoes that transmit malaria has been the mainstay in the fight against the disease, but alternative methods are required in view of emerging insecticide resistance. Entomopathogenic fungi are candidate alternatives, but to date, few trials have translated the use of these agents to field-based evaluations of their actual impact on mosquito survival and malaria risk. Mineral oil-formulations of the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana were applied using five different techniques that each exploited the behaviour of malaria mosquitoes when entering, host-seeking or resting in experimental huts in a malaria endemic area of rural Tanzania. Results Survival of mosquitoes was reduced by 39-57% relative to controls after forcing upward house-entry of mosquitoes through fungus treated baffles attached to the eaves or after application of fungus-treated surfaces around an occupied bed net (bed net strip design). Moreover, 68 to 76% of the treatment mosquitoes showed fungal growth and thus had sufficient contact with fungus treated surfaces. A population dynamic model of malaria-mosquito interactions shows that these infection rates reduce malaria transmission by 75-80% due to the effect of fungal infection on adult mortality alone. The model also demonstrated that even if a high proportion of the mosquitoes exhibits outdoor biting behaviour, malaria transmission was still significantly reduced. Conclusions Entomopathogenic fungi strongly affect mosquito survival and have a high predicted impact on malaria transmission. These entomopathogens represent a viable alternative for malaria control, especially if they are used as part of an integrated vector management strategy. PMID:22449130

Rapid reduction of malaria following introduction of vector control interventions in Tororo District, Uganda: a descriptive study.

PubMed

Oguttu, David W; Matovu, Joseph K B; Okumu, David C; Ario, Alex R; Okullo, Allen E; Opigo, Jimmy; Nankabirwa, Victoria

2017-05-30

In 2012, Tororo District had the highest malaria burden in Uganda with community Plasmodium prevalence of 48%. To control malaria in the district, the Ministry of Health introduced universal distribution of long lasting insecticide-treated nets (LLINs) in 2013 and added indoor residual spraying (IRS) in 2014. This study assessed malaria incidence, test positivity rates and outpatient (OPD) attendance due to malaria before and after vector control interventions. This study was based on analysis of Health Management Information System (HMIS) secondary malaria surveillance data of 2,727,850 patient records in OPD registers of 61 health facilities from 2012 to 2015. The analysis estimated monthly malaria incidence for the entire population and also separately for <5- and ≥5-year-olds before and after introduction of vector control interventions; determined laboratory test positivity rates and annual percentage of malaria cases in OPD. Chi square for trends was used to analyse annual change in malaria incidence and logistic regression for monthly reduction. Following universal LLINs coverage, the annual mean monthly malaria incidence fell from 95 cases in 2013 to 76 cases per 1000 in 2014 with no significant monthly reduction (OR = 0.99, 95% CI 0.96-1.01, P = 0.37). Among children <5 years, the malaria incidence reduced from 130 to 100 cases per 1000 (OR = 0.98, 95% CI 0.97-1.00, P = 0.08) when LLINs were used alone in 2014, but declined to 45 per 1000 in 2015 when IRS was combined with LLINs (OR = 0.94, 95% CI 0.91-0.996, P < 0.0001). Among individuals aged ≥5 years, mean monthly malaria incidence reduced from 59 to 52 cases per 1000 (OR = 0.99, 95% CI 0.97-1.02, P = 0.8) when LLINs were used alone in 2014, but reduced significantly to 25 per 1000 in 2015 (OR = 0.91, 95% CI 0.88-0.94, P < 0.0001). Malaria test positivity rate reduced from 57% in 2013 to 30% (Chi = 15, P < 0.0001) in 2015. Slide positivity rate reduced from 45% in 2013 to 21% in 2015 (P = 0.004) while RDT positivity declined from 69 to 40%. A rapid reduction in malaria incidence was observed in Tororo District following the introduction of IRS in addition to LLINs. There was no significant reduction in malaria incidence following universal distribution of LLINs to communities before introduction of IRS.

The El Niño Southern Oscillation and malaria epidemics in South America

NASA Astrophysics Data System (ADS)

Gagnon, Alexandre S.; Smoyer-Tomic, Karen E.; Bush, Andrew B.

2002-05-01

A better understanding of the relationship between the El Niño Southern Oscillation (ENSO), the climatic anomalies it engenders, and malaria epidemics could help mitigate the world-wide increase in incidence of this mosquito-transmitted disease. The purpose of this paper is to assess the possibility of using ENSO forecasts for improving malaria control. This paper analyses the relationship between ENSO events and malaria epidemics in a number of South American countries (Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, and Venezuela). A statistically significant relationship was found between El Niño and malaria epidemics in Colombia, Guyana, Peru, and Venezuela. We demonstrate that flooding engenders malaria epidemics in the dry coastal region of northern Peru, while droughts favor the development of epidemics in Colombia and Guyana, and epidemics lag a drought by 1 year in Venezuela. In Brazil, French Guiana, and Ecuador, where we did not detect an ENSO/malaria signal, non-climatic factors such as insecticide sprayings, variation in availability of anti-malaria drugs, and population migration are likely to play a stronger role in malaria epidemics than ENSO-generated climatic anomalies. In some South American countries, El Niño forecasts show strong potential for informing public health efforts to control malaria.

Leucocyte migration and nitroblue tetrazolium assay in Nigerian children with bacteremia and malaria parasitemia.

PubMed

Ganiyu, Arinola O; Abayomi, Odetunde B; Oludele, Adebiyi E; Gladys, Falusi A

2004-12-01

The prevalence of malaria parasitemia, bacteremia, certain hematological parameters, leucocyte migration index and nitroblue tetrazolium dye reduction were determined in 147 Nigerian children (4.24+/-2.88 years of age). Sixty (40.8%), 28(19.1%) and 26(17.7%) had malaria parasitemia only, bacteremia only and both malaria parasitemia and bacteremia, respectively. Four genera of bacteria, i.e E. coli, Proteus, Staphylococcus and Salmonella, were detected in subjects with both malaria parasitemia and bacteremia. The 4 bacterial genera and Klebsiella were detected in subjects with bacterial infection only. P. falciparum (68%), P. malariae (25%) and P. ovale (7%) were the species of malaria parasites identified in our subjects. Bacteremia was most prevalent in subjects with hemoglobin AA (HbAA) (60.7%) followed by HbAC (21.45%). Packed cell volume (PCV) and Hb concentration were similar in all groups but mean counts of red blood cells (RBC) and white blood cells (WBC) were statistically significantly lower in subjects with malaria parasites only compared to the controls. Leucocyte migration was significantly reduced in children with bacteremia only or both malaria parasitemia and bacteremia compared to controls, while the nitroblue tetrazolium assay was significantly reduced in children with bacteremia only. It may be concluded that malaria parasitemia significantly affects both leucocyte migration and nitroblue tetrazolium assay.

The Influence of Dams on Malaria Transmission in Sub-Saharan Africa.

PubMed

Kibret, Solomon; Wilson, G Glenn; Ryder, Darren; Tekie, Habte; Petros, Beyene

2017-06-01

The construction of dams in sub-Saharan Africa is pivotal for food security and alleviating poverty in the region. However, the unintended adverse public health implications of extending the spatial distribution of water infrastructure are poorly documented and may minimize the intended benefits of securing water supplies. This paper reviews existing studies on the influence of dams on the spatial distribution of malaria parasites and vectors in sub-Saharan Africa. Common themes emerging from the literature were that dams intensified malaria transmission in semi-arid and highland areas with unstable malaria transmission but had little or no impact in areas with perennial transmission. Differences in the impacts of dams resulted from the types and characteristics of malaria vectors and their breeding habitats in different settings of sub-Saharan Africa. A higher abundance of a less anthropophilic Anopheles arabiensis than a highly efficient vector A. gambiae explains why dams did not increase malaria in stable areas. In unstable areas where transmission is limited by availability of water bodies for vector breeding, dams generally increase malaria by providing breeding habitats for prominent malaria vector species. Integrated vector control measures that include reservoir management, coupled with conventional malaria control strategies, could optimize a reduction of the risk of malaria transmission around dams in the region.

Comparative evaluation of the diagnosis, reporting and investigation of malaria cases in China, 2005-2014: transition from control to elimination for the national malaria programme.

PubMed

Sun, Jun-Ling; Zhou, Sheng; Geng, Qi-Bin; Zhang, Qian; Zhang, Zi-Ke; Zheng, Can-Jun; Hu, Wen-Biao; Clements, Archie C A; Lai, Sheng-Jie; Li, Zhong-Jie

2016-06-27

The elimination of malaria requires high-quality surveillance data to enable rapid detection and response to individual cases. Evaluation of the performance of a national malaria surveillance system could identify shortcomings which, if addressed, will improve the surveillance program for malaria elimination. Case-level data for the period 2005-2014 were extracted from the China National Notifiable Infectious Disease Reporting Information System and Malaria Enhanced Surveillance Information System. The occurrence of cases, accuracy and timeliness of case diagnosis, reporting and investigation, were assessed and compared between the malaria control stage (2005-2010) and elimination stage (2011-2014) in mainland China. A total of 210 730 malaria cases were reported in mainland China in 2005-2014. The average annual incidence declined dramatically from 2.5 per 100 000 people at the control stage to 0.2 per 100 000 at the elimination stage, but the proportion of migrant cases increased from 9.8 % to 41.0 %. Since the initiation of the National Malaria Elimination Programme in 2010, the overall proportion of cases diagnosed by laboratory testing consistently improved, with the highest of 99.0 % in 2014. However, this proportion was significantly lower in non-endemic provinces (79.0 %) than that in endemic provinces (91.4 %) during 2011-2014. The median interval from illness onset to diagnosis was 3 days at the elimination stage, with one day earlier than that at the control stage. Since 2011, more than 99 % cases were reported within 1 day after being diagnosed, while the proportion of cases that were reported within one day after diagnosis was lowest in Tibet (37.5 %). The predominant source of cases reporting shifted from town-level hospitals at the control stage (67.9 % cases) to city-level hospitals and public health institutes at the eliminate stage (69.4 % cases). The proportion of investigation within 3 days after case reporting has improved, from 74.6 % in 2010 to 98.5 % in 2014. The individual case-based malaria surveillance system in China operated well during the malaria elimination stage. This ensured that malaria cases could be diagnosed, reported and timely investigated at local level. However, domestic migrants and overseas populations, as well as cases in the historically malarial non-endemic areas and hard-to-reach area are new challenges in the surveillance for malaria elimination.

Combating severe malaria in African children*

PubMed Central

Breman, J. G.; Campbell, C. C.

1988-01-01

An initiative to reduce childhood mortality due to malaria, diarrhoea and vaccine-preventable diseases, called the Africa Child Survival Initiative—Combatting Childhood Communicable Diseases (CCCD) project, was started in 1982 and is now operating in 13 African countries, 12 of which are endemic for malaria. The project's malaria control strategy relies on the use of drugs, mainly chloroquine, to prevent severe illness and death in children less than 5 years of age; chemoprophylaxis for pregnant women is also advised to prevent low birth weight in newborns. The strategy is based on WHO recommendations which focus on improved diagnosis and treatment of cases and chemoprophylaxis for pregnant women. In 9 out of the 13 CCCD countries the sensitivity of Plasmodium falciparum to chloroquine in children was investigated and a drug sensitivity surveillance network was established. In areas with chloroquine-resistant P. falciparum, treatment with chloroquine was found to decrease the temperature in febrile children and to greatly reduce the parasite density, thus preventing severe illness and possible death. Baseline surveys in 6 countries have shown a wide range of treatment practices, e.g., use of chloroquine in various doses without standard guidelines and the excessive use of quinine and chloroquine injections in some health units. As pregnant women are often not taking chemoprophylaxis, research has been started on alternative approaches to drug treatment to prevent the adverse effects of malaria on the fetus. Only 4 of the 12 malarious countries had malaria control units when their CCCD programme began and these were concerned mainly with vector control issues; 11 of 12 countries now have such units and a written CCCD malaria plan. These countries have now integrated malaria control activities into primary health care and have begun to implement standardized treatment and prevention practices that are described in their national CCCD malaria plans. PMID:3061675

Optimal vaccination and bednet maintenance for the control of malaria in a region with naturally acquired immunity.

PubMed

Prosper, Olivia; Ruktanonchai, Nick; Martcheva, Maia

2014-07-21

Following over two decades of research, the malaria vaccine candidate RTS,S has reached the final stages of vaccine trials, demonstrating an efficacy of roughly 50% in young children. Regions with high malaria prevalence tend to have high levels of naturally acquired immunity (NAI) to severe malaria; NAI is caused by repeated exposure to infectious bites and results in large asymptomatic populations. To address concerns about how these vaccines will perform in regions with existing NAI, we developed a simple malaria model incorporating vaccination and NAI. Typically, if the basic reproduction number (R0) for malaria is greater than unity, the disease will persist; otherwise, the disease will become extinct. However, analysis of this model revealed that NAI, compounded by a subpopulation with only partial protection to malaria, may render vaccination efforts ineffective and potentially detrimental to malaria control, by increasing R0 and increasing the likelihood of malaria persistence even when R0<1. The likelihood of this scenario increases when non-immune infected individuals are treated disproportionately compared with partially immune individuals - a plausible scenario since partially immune individuals are more likely to be asymptomatically infected. Consequently, we argue that active case-detection of asymptomatic infections is a critical component of an effective malaria control program. We then investigated optimal vaccination and bednet control programs under two endemic settings with varying levels of naturally acquired immunity: a typical setting under which prevalence decays when R0<1, and a setting in which subthreshold endemic equilibria exist. A qualitative comparison of the optimal control results under the first setting revealed that the optimal policy differs depending on whether the goal is to reduce total morbidity, or to reduce clinical infections. Furthermore, this comparison dictates that control programs should place less effort in vaccination as the level of NAI in a population, and as disease prevalence, increases. In the second setting, we demonstrated that the optimal policy is able to confer long-term benefits with a 10-year control program by pushing the system into a new state where the disease-free equilibrium becomes the attracting equilibrium. While this result suggests that one can theoretically achieve long-term benefits with a short-term strategy, we illustrate that in this second setting, a small environmental change, or the introduction of new cases via immigration, places the population at high risk for a malaria epidemic. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparative Evaluation of Bivalent Malaria Rapid Diagnostic Tests versus Traditional Methods in Field with Special Reference to Heat Stability Testing in Central India

PubMed Central

Singh, Neeru; Bharti, Praveen K.; Singh, Mrigendra P.; Mishra, Sweta; Shukla, Man M.; Sharma, Ravendra K.; Singh, Rajesh K.

2013-01-01

Background Malaria presents a diagnostic challenge in areas where both Plasmodium falciparum and P.vivax are co-endemic. Bivalent Rapid Diagnostic tests (RDTs) showed promise as diagnostic tools for P.falciparum and P.vivax. To assist national malaria control programme in the selection of RDTs, commercially available seven malaria RDTs were evaluated in terms of their performance with special reference to heat stability. Methodology/Principal Findings This study was undertaken in four forested districts of central India (July, 2011– March, 2012). All RDTs were tested simultaneously in field along with microscopy as gold standard. These RDTs were stored in their original packing at 25°C before transport to the field or they were stored at 35°C and 45°C upto 100 days for testing the performance of RDTs at high temperature. In all 2841 patients with fever were screened for malaria of which 26% were positive for P.falciparum, and 17% for P.vivax. The highest sensitivity of any RDT for P.falciparum was 98% (95% CI; 95.9–98.8) and lowest sensitivity was 76% (95% CI; 71.7–79.6). For P.vivax highest and lowest sensitivity for any RDT was 80% (95% CI; 94.9 - 83.9) and 20% (95% CI; 15.6–24.5) respectively. Heat stability experiments showed that most RDTs for P.falciparum showed high sensitivity at 45°C upto 90 days. While for P.vivax only two RDTs maintained good sensitivity upto day 90 when compared with RDTs kept at room temperature. Agreement between observers was excellent for positive and negative readings for both P.falciparum and P.vivax (Kappa >0.6–0.9). Conclusion This is first field evaluation of RDTs regarding their temperature stability. Although RDTs are useful as diagnostic tool for P.falciparum and P.vivax even at high temperature, the quality of RDTs should be regulated and monitored more closely. PMID:23472135

Strengthening tactical planning and operational frameworks for vector control: the roadmap for malaria elimination in Namibia.

PubMed

Chanda, Emmanuel; Ameneshewa, Birkinesh; Angula, Hans A; Iitula, Iitula; Uusiku, Pentrina; Trune, Desta; Islam, Quazi M; Govere, John M

2015-08-05

Namibia has made tremendous gains in malaria control and the epidemiological trend of the disease has changed significantly over the past years. In 2010, the country reoriented from the objective of reducing disease morbidity and mortality to the goal of achieving malaria elimination by 2020. This manuscript outlines the processes undertaken in strengthening tactical planning and operational frameworks for vector control to facilitate expeditious malaria elimination in Namibia. The information sources for this study included all available data and accessible archived documentary records on malaria vector control in Namibia. A methodical assessment of published and unpublished documents was conducted via a literature search of online electronic databases, Google Scholar, PubMed and WHO, using a combination of search terms. To attain the goal of elimination in Namibia, systems are being strengthened to identify and clear all infections, and significantly reduce human-mosquito contact. Particularly, consolidating vector control for reducing transmission at the identified malaria foci will be critical for accelerated malaria elimination. Thus, guarding against potential challenges and the need for evidence-based and sustainable vector control instigated the strengthening of strategic frameworks by: adopting the integrated vector management (IVM) strategy; initiating implementation of the global plan for insecticide resistance management (GPIRM); intensifying malaria vector surveillance; improving data collection and reporting systems on DDT; updating the indoor residual spraying (IRS) data collection and reporting tool; and, improving geographical reconnaissance using geographical information system-based satellite imagery. Universal coverage with IRS and long-lasting insecticidal nets, supplemented by larval source management in the context of IVM and guided by vector surveillance coupled with rational operationalization of the GPIRM, will enable expeditious attainment of elimination in Namibia. However, national capacity to plan, implement, monitor and evaluate interventions will require adequate and sustained support for technical, physical infrastructure, and human and financial resources for entomology and vector control operations.

How absolute is zero? An evaluation of historical and current definitions of malaria elimination.

PubMed

Cohen, Justin M; Moonen, Bruno; Snow, Robert W; Smith, David L

2010-07-22

Decisions to eliminate malaria from all or part of a country involve a complex set of factors, and this complexity is compounded by ambiguity surrounding some of the key terminology, most notably "control" and "elimination." It is impossible to forecast resource and operational requirements accurately if endpoints have not been defined clearly, yet even during the Global Malaria Eradication Program, debate raged over the precise definition of "eradication." Analogous deliberations regarding the meaning of "elimination" and "control" are basically nonexistent today despite these terms' core importance to programme planning. To advance the contemporary debate about these issues, this paper presents a historical review of commonly used terms, including control, elimination, and eradication, to help contextualize current understanding of these concepts. The review has been supported by analysis of the underlying mathematical concepts on which these definitions are based through simple branching process models that describe the proliferation of malaria cases following importation. Through this analysis, the importance of pragmatic definitions that are useful for providing malaria control and elimination programmes with a practical set of strategic milestones is emphasized, and it is argued that current conceptions of elimination in particular fail to achieve these requirements. To provide all countries with precise targets, new conceptual definitions are suggested to more precisely describe the old goals of "control" - here more exactly named "controlled low-endemic malaria" - and "elimination." Additionally, it is argued that a third state, called "controlled non-endemic malaria," is required to describe the epidemiological condition in which endemic transmission has been interrupted, but malaria resulting from onwards transmission from imported infections continues to occur at a sufficiently high level that elimination has not been achieved. Finally, guidelines are discussed for deriving the separate operational definitions and metrics that will be required to make these concepts relevant, measurable, and achievable for a particular environment.

Urbanization and the global malaria recession.

PubMed

Tatem, Andrew J; Gething, Peter W; Smith, David L; Hay, Simon I

2013-04-17

The past century has seen a significant contraction in the global extent of malaria transmission, resulting in over 50 countries being declared malaria free, and many regions of currently endemic countries eliminating the disease. Moreover, substantial reductions in transmission have been seen since 1900 in those areas that remain endemic today. Recent work showed that this malaria recession was unlikely to have been driven by climatic factors, and that control measures likely played a significant role. It has long been considered, however, that economic development, and particularly urbanization, has also been a causal factor. The urbanization process results in profound socio-economic and landscape changes that reduce malaria transmission, but the magnitude and extent of these effects on global endemicity reductions are poorly understood. Global data at subnational spatial resolution on changes in malaria transmission intensity and urbanization trends over the past century were combined to examine the relationships seen over a range of spatial and temporal scales. A consistent pattern of increased urbanization coincident with decreasing malaria transmission and elimination over the past century was found. Whilst it remains challenging to untangle whether this increased urbanization resulted in decreased transmission, or that malaria reductions promoted development, the results point to a close relationship between the two, irrespective of national wealth. The continuing rapid urbanization in malaria-endemic regions suggests that such malaria declines are likely to continue, particularly catalyzed by increasing levels of direct malaria control.

Distribution of sibling species of Anopheles culicifacies s.l. and Anopheles fluviatilis s.l. and their vectorial capacity in eight different malaria endemic districts of Orissa, India.

PubMed

Tripathy, Asima; Samanta, Luna; Das, Sachidananda; Parida, Sarat Kumar; Marai, Nitisheel; Hazra, Rupenansu Kumar; Kar, Santanu Kumar; Mahapatra, Namita

2010-12-01

The study was undertaken in eight endemic districts of Orissa, India, to find the members of the species complexes of Anopheles culicifacies and Anopheles fluviatilis and their distribution patterns. The study area included six forested districts (Keonjhar, Angul, Dhenkanal, Ganjam, Nayagarh and Khurda) and two non-forested coastal districts (Puri and Jagatsingpur) studied over a period of two years (June 2007-May 2009). An. culicifacies A, B, C and D and An. fluviatilis S and T sibling species were reported. The prevalence of An. culicifacies A ranged from 4.2-8.41%, B from 54.96-76.92%, C from 23.08-33.62% and D from 1.85-5.94% (D was reported for the first time in Orissa, except for occurrences in the Khurda and Nayagarh districts). The anthropophilic indices (AI) were 3.2-4.8%, 0.5-1.7%, 0.7-1.37% and 0.91-1.35% for A, B, C and D, respectively, whereas the sporozoite rates (SR) were 0.49-0.54%, 0%, 0.28-0.37% and 0.41-0.46% for A, B, C and D, respectively. An. fluviatilis showed a similarly varied distribution pattern in which S was predominant (84.3% overall); its AI and SR values ranged from 60.7-90.4% and 1.2-2.32%, respectively. The study observed that the co-existence of potential vector sibling species of An. culicifacies (A, C and D) and An. fluviatilis S (> 50%) was responsible for the high endemicity of malaria in forested districts such as Dhenkanal, Keonjhar, Angul, Ganjam, Nayagarh and Khurda (> 5% slide positivity rate). Thus, the epidemiological scenario for malaria is dependent on the distribution of the vector sibling species and their vectorial capacity.

Use and Effects of Malaria Control Measures in Pregnancy in Lagos, Nigeria

PubMed Central

Amoo, A. O. J.; Akintunde, Grace B.; Ojelekan, Oluwole D.; König, Wolfgang; König, Brigitte

2011-01-01

In Nigeria, malaria causes up to 11% of maternal mortality. Our main aim was to find out the most common mosquito control measures employed by the pregnant women in Lagos and their effects on malaria infection. The study was carried out over a period of 6 months during which trained interviewers administered questionnaires to 400 pregnant women. The prevalence of malaria was 8.4%. There was no significant association between the prevalence of malaria and age, level of education, or occupation of the participants. Pregnant women in the age range 26-30 had the mean parasite density (409.9±196.80). Insecticide spray (32.8%), mosquito coil (27.5%), and insecticide-treated nets (ITN) (15.5%) were the major mosquito control measures employed by the participants while the prevalence of infection among them were 2.3%, 6.2%, and 3.2%, respectively (P<0.05). Only 18.3% of the women had taken more than one dose of intermittent preventive treatment (IPT), while another 11.8% had taken a single dose. The infection rate among them was 4.1% and 6.4%, respectively. Malaria prevalence was highest among those who had not received any dose of IPT (10%). This study showed that the use of ITN and IPT among the pregnant women were still unacceptably low. It also showed that the use of insecticide spray which was the most common malaria control measure adopted by the participants was effective despite the fact that it is not a National Malaria Control Policy. We recommend that a sustained integrated mosquito management and public education should be strengthened in Nigeria. PMID:22355203

Towards a strategy for malaria in pregnancy in Afghanistan: analysis of clinical realities and women's perceptions of malaria and anaemia.

PubMed

Howard, Natasha; Enayatullah, Sayed; Mohammad, Nader; Mayan, Ismail; Shamszai, Zohra; Rowland, Mark; Leslie, Toby

2015-11-04

Afghanistan has some of the worst maternal and infant mortality indicators in the world and malaria is a significant public health concern. Study objectives were to assess prevalence of malaria and anaemia, related knowledge and practices, and malaria prevention barriers among pregnant women in eastern Afghanistan. Three studies were conducted: (1) a clinical survey of maternal malaria, maternal anaemia, and neonatal birthweight in a rural district hospital delivery-ward; (2) a case-control study of malaria risk among reproductive-age women attending primary-level clinics; and (3) community surveys of malaria and anaemia prevalence, socioeconomic status, malaria knowledge and reported behaviour among pregnant women. Among 517 delivery-ward participants (1), one malaria case (prevalence 1.9/1000), 179 anaemia cases (prevalence 346/1000), and 59 low-birthweight deliveries (prevalence 107/1000) were detected. Anaemia was not associated with age, gravidity, intestinal parasite prevalence, or low-birthweight at delivery. Among 141 malaria cases and 1010 controls (2), no association was found between malaria infection and pregnancy (AOR 0.89; 95 % CI 0.57-1.39), parity (AOR 0.95; 95 % CI 0.85-1.05), age (AOR 1.02; 95 % CI 1.00-1.04), or anaemia (AOR 1.00; 95 % CI 0.65-1.54). Those reporting insecticide-treated net usage had 40 % reduced odds of malaria infection (AOR 0.60; 95 % CI 0.40-0.91). Among 530 community survey participants (3), malaria and anaemia prevalence were 3.9/1000 and 277/1000 respectively, with 34/1000 experiencing severe anaemia. Despite most women having no formal education, malaria knowledge was high. Most expressed reluctance to take malaria preventive medication during pregnancy, deeming it potentially unsafe. Given the low malaria risk and reported avoidance of medication during pregnancy, intermittent preventive treatment is hard to justify or implement. Preventive strategy should instead focus on long-lasting insecticidal nets for all pregnant women.

Malaria morbidity and mortality trends in Manicaland province, Zimbabwe, 2005-2014.

PubMed

Mutsigiri, Faith; Mafaune, Patron Trish; Mungati, More; Shambira, Gerald; Bangure, Donewell; Juru, Tsitsi; Gombe, Notion Tafara; Tshimanga, Mufuta

2017-01-01

Zimbabwe targets reducing malaria incidence from 22/1000 in 2012 to 10/1000 by 2017, and malaria deaths to near zero by 2017. As the country moves forward with the malaria elimination efforts, it is crucial to monitor trends in malaria morbidity and mortality in the affected areas. In 2013, Manicaland Province contributed 51% of all malaria cases and 35% of all malaria deaths in Zimbabwe. This analysis describes the trends in malaria incidence, case fatality and malaria outpatient workload compared to the general outpatient workload. We analyzed routinely captured malaria data in Manicaland Province for the period 2005 to 2014. Epi Info version 7 was used to calculate chi-square trends for significance and Microsoft Excel was used to generate graphs. Permission to analyze the data was sought and granted by the Provincial Medical Directorate Institutional Review Board of Manicaland and the Health Studies office. Malaria morbidity data for the period 2005-2014 was reviewed and a total of 947,462 cases were confirmed during this period. However, malaria mortality data was only available for the period 2011-2014 and cumulatively 696 deaths were reported. Malaria incidence increased from 4.4/1,000 persons in 2005 to 116.3/1,000 persons in 2014 (p<0.001). The incidence was higher among females compared to males (p-trend<0.001) and among the above five years age group compared to the under-fives (p-trend<0.001). The proportion of all Outpatient Department attendances that were malaria cases increased 30 fold from 0.3% in 2005 to 9.1% in 2014 (p-trend<0.001). The Case Fatality Rate also increased 2-fold from 0.05 in 2011 to 0.1 in 2014 (p-trend<0.001). Despite current malaria control strategies, the morbidity and mortality of malaria increased over the period under review. There is need for further strengthening of malaria control interventions to reduce the burden of the disease.

Modelling the influence of climate on malaria occurrence in Chimoio Municipality, Mozambique.

PubMed

Ferrão, João Luís; Mendes, Jorge M; Painho, Marco

2017-05-25

Mozambique was recently ranked fifth in the African continent for the number of cases of malaria. In Chimoio municipality cases of malaria are increasing annually, contrary to the decreasing trend in Africa. As malaria transmission is influenced to a large extent by climatic conditions, modelling this relationship can provide useful insights for designing precision health measures for malaria control. There is a scarcity of information on the association between climatic variability and malaria transmission risk in Mozambique in general, and in Chimoio in particular. Therefore, the aim of this study is to model the association between climatic variables and malaria cases on a weekly basis, to help policy makers find adequate measures for malaria control and eradication. Time series analysis was conducted using data on weekly climatic variables and weekly malaria cases (counts) in Chimoio municipality, from 2006 to 2014. All data were analysed using SPSS-20, R 3.3.2 and BioEstat 5.0. Cross-correlation analysis, linear processes, namely ARIMA models and regression modelling, were used to develop the final model. Between 2006 and 2014, 490,561 cases of malaria were recorded in Chimoio. Both malaria and climatic data exhibit weekly and yearly systematic fluctuations. Cross-correlation analysis showed that mean temperature and precipitation present significantly lagged correlations with malaria cases. An ARIMA model (2,1,0) (2,1,1) 52 , and a regression model for a Box-Cox transformed number of malaria cases with lags 1, 2 and 3 of weekly malaria cases and lags 6 and 7 of weekly mean temperature and lags 12 of precipitation were fitted. Although, both produced similar widths for prediction intervals, the last was able to anticipate malaria outbreak more accurately. The Chimoio climate seems ideal for malaria occurrence. Malaria occurrence peaks during January to March in Chimoio. As the lag effect between climatic events and malaria occurrence is important for the prediction of malaria cases, this can be used for designing public precision health measures. The model can be used for planning specific measures for Chimoio municipality. Prospective and multidisciplinary research involving researchers from different fields is welcomed to improve the effect of climatic factors and other factors in malaria cases.

Early malaria resurgence in pre-elimination areas in Kokap Subdistrict, Kulon Progo, Indonesia

PubMed Central

2014-01-01

Background Indonesia is among those countries committed to malaria eradication, with a continuously decreasing incidence of malaria. However, at district level the situation is different. This study presents a case of malaria resurgence Kokap Subdistrict of the Kulon Progo District in Yogyakarta Province, Java after five years of low endemicity. This study also aims to describe the community perceptions and health services delivery situation that contribute to this case. Methods All malaria cases (2007–2011) in Kulon Progo District were stratified to annual parasite incidence (API). Two-hundred and twenty-six cases during an outbreak (May 2011 to April 2012) were geocoded by household addresses using a geographic information system (GIS) technique and clusters were identified by SaTScan software analysis (Arc GIS 10.1). Purposive random sampling was conducted on respondents living inside the clusters to identify community perceptions and behaviour related to malaria. Interviews were conducted with malaria health officers to understand the challenges of malaria surveillance and control. Results After experiencing three consecutive years with API less than 1 per thousand, malaria in Kokap subdistrict increased almost ten times higher than API in the district level and five times higher than national API. Malaria cases were found in all five villages in 2012. One primary and two secondary malaria clusters in Hargotirto and Kalirejo villages were identified during the 2011–2012 outbreak. Most of the respondents were positively aware with malaria signs and activities of health workers to prevent malaria, although some social economic activities could not be hindered. Return transmigrants or migrant workers entering to their villages, reduced numbers of village malaria workers and a surge in malaria cases in the neighbouring district contributed to the resurgence. Conclusion Community perception, awareness and participation could constitute a solid foundation for malaria elimination in Kokap. However, decreasing number of village malaria workers and ineffective communication between primary health centres (PHCs) within boundary areas with similar malaria problems needs attention. Decentralization policy was allegedly the reason for the less integrated malaria control between districts, especially in the cross border areas. Malaria resurgence needs attention particularly when it occurs in an area that is entering the elimination phase. PMID:24684702

School-based surveys of malaria in Oromia Regional State, Ethiopia: a rapid survey method for malaria in low transmission settings

PubMed Central

2011-01-01

Background In Ethiopia, malaria transmission is seasonal and unstable, with both Plasmodium falciparum and Plasmodium vivax endemic. Such spatial and temporal clustering of malaria only serves to underscore the importance of regularly collecting up-to-date malaria surveillance data to inform decision-making in malaria control. Cross-sectional school-based malaria surveys were conducted across Oromia Regional State to generate up-to-date data for planning malaria control interventions, as well as monitoring and evaluation of operational programme implementation. Methods Two hundred primary schools were randomly selected using a stratified and weighted sampling frame; 100 children aged five to 18 years were then randomly chosen within each school. Surveys were carried out in May 2009 and from October to December 2009, to coincide with the peak of malaria transmission in different parts of Oromia. Each child was tested for malaria by expert microscopy, their haemoglobin measured and a simple questionnaire completed. Satellite-derived environmental data were used to assess ecological correlates of Plasmodium infection; Bayesian geostatistical methods and Kulldorff's spatial scan statistic were employed to investigate spatial heterogeneity. Results A total 20,899 children from 197 schools provided blood samples, two selected schools were inaccessible and one school refused to participate. The overall prevalence of Plasmodium infection was found to be 0.56% (95% CI: 0.46-0.67%), with 53% of infections due to P. falciparum and 47% due to P. vivax. Of children surveyed, 17.6% (95% CI: 17.0-18.1%) were anaemic, while 46% reported sleeping under a mosquito net the previous night. Malaria was found at 30 (15%) schools to a maximum elevation of 2,187 metres, with school-level Plasmodium prevalence ranging between 0% and 14.5%. Although environmental variables were only weakly associated with P. falciparum and P. vivax infection, clusters of infection were identified within Oromia. Conclusion These findings demonstrate the marked spatial heterogeneity of malaria in Oromia and, in general, Ethiopia, and provide a strong epidemiological basis for planning as well as monitoring and evaluating malaria control in a setting with seasonal and unstable malaria transmission. PMID:21288368

Changing epidemiology of malaria in Sabah, Malaysia: increasing incidence of Plasmodium knowlesi.

PubMed

William, Timothy; Jelip, Jenarun; Menon, Jayaram; Anderios, Fread; Mohammad, Rashidah; Awang Mohammad, Tajul A; Grigg, Matthew J; Yeo, Tsin W; Anstey, Nicholas M; Barber, Bridget E

2014-10-02

While Malaysia has had great success in controlling Plasmodium falciparum and Plasmodium vivax, notifications of Plasmodium malariae and the microscopically near-identical Plasmodium knowlesi increased substantially over the past decade. However, whether this represents microscopic misdiagnosis or increased recognition of P. knowlesi has remained uncertain. To describe the changing epidemiology of malaria in Sabah, in particular the increasing incidence of P. knowlesi, a retrospective descriptive study was undertaken involving a review of Department of Health malaria notification data from 2012-2013, extending a previous review of these data from 1992-2011. In addition, malaria PCR and microscopy data from the State Public Health Laboratory were reviewed to estimate the accuracy of the microscopy-based notification data. Notifications of P. malariae/P. knowlesi increased from 703 in 2011 to 815 in 2012 and 996 in 2013. Notifications of P. vivax and P. falciparum decreased from 605 and 628, respectively, in 2011, to 297 and 263 in 2013. In 2013, P. malariae/P. knowlesi accounted for 62% of all malaria notifications compared to 35% in 2011. Among 1,082 P. malariae/P. knowlesi blood slides referred for PCR testing during 2011-2013, there were 924 (85%) P. knowlesi mono-infections, 30 (2.8%) P. falciparum, 43 (4.0%) P. vivax, seven (0.6%) P. malariae, six (0.6%) mixed infections, 31 (2.9%) positive only for Plasmodium genus, and 41 (3.8%) Plasmodium-negative. Plasmodium knowlesi mono-infection accounted for 32/156 (21%) and 33/87 (38%) blood slides diagnosed by microscopy as P. falciparum and P. vivax, respectively. Twenty-six malaria deaths were reported during 2010-2013, including 12 with 'P. malariae/P. knowlesi' (all adults), 12 with P. falciparum (seven adults), and two adults with P. vivax. Notifications of P. malariae/P. knowlesi in Sabah are increasing, with this trend likely reflecting a true increase in incidence of P. knowlesi and presenting a major threat to malaria control and elimination in Malaysia. With the decline of P. falciparum and P. vivax, control programmes need to incorporate measures to protect against P. knowlesi, with further research required to determine effective interventions.

Social and behavior change communication in the fight against malaria in Mozambique

PubMed Central

Arroz, Jorge Alexandre Harrison

2017-01-01

ABSTRACT Long-lasting insecticide-treated nets and/or indoor residual spraying, associated with case management, are key interventions in the control of malaria in Africa. The objective of this study is to comment on the role of social and behavior change communication as a potential key intervention in the control of malaria in Mozambique. PMID:28355338

Effect of climatic variability on malaria trends in Baringo County, Kenya.

PubMed

Kipruto, Edwin K; Ochieng, Alfred O; Anyona, Douglas N; Mbalanya, Macrae; Mutua, Edna N; Onguru, Daniel; Nyamongo, Isaac K; Estambale, Benson B A

2017-05-25

Malaria transmission in arid and semi-arid regions of Kenya such as Baringo County, is seasonal and often influenced by climatic factors. Unravelling the relationship between climate variables and malaria transmission dynamics is therefore instrumental in developing effective malaria control strategies. The main aim of this study was to describe the effects of variability of rainfall, maximum temperature and vegetation indices on seasonal trends of malaria in selected health facilities within Baringo County, Kenya. Climate variables sourced from the International Research Institute (IRI)/Lamont-Doherty Earth Observatory (LDEO) climate database and malaria cases reported in 10 health facilities spread across four ecological zones (riverine, lowland, mid-altitude and highland) between 2004 and 2014 were subjected to a time series analysis. A negative binomial regression model with lagged climate variables was used to model long-term monthly malaria cases. The seasonal Mann-Kendall trend test was then used to detect overall monotonic trends in malaria cases. Malaria cases increased significantly in the highland and midland zones over the study period. Changes in malaria prevalence corresponded to variations in rainfall and maximum temperature. Rainfall at a time lag of 2 months resulted in an increase in malaria transmission across the four zones while an increase in temperature at time lags of 0 and 1 month resulted in an increase in malaria cases in the riverine and highland zones, respectively. Given the existence of a time lag between climatic variables more so rainfall and peak malaria transmission, appropriate control measures can be initiated at the onset of short and after long rains seasons.

Factors Associated with the Rapid and Durable Decline in Malaria Incidence in El Salvador, 1980-2017.

PubMed

Burton, Robert A; Chévez, José Eduardo Romero; Sauerbrey, Mauricio; Guinovart, Caterina; Hartley, Angela; Kirkwood, Geoffrey; Boslego, Matthew; Gavidia, Mirna Elizabeth; Alemán Escobar, Jaime Enrique; Turkel, Rachel; Steketee, Richard W; Slutsker, Laurence; Schneider, Kammerle; Kent Campbell, Carlos C

2018-05-14

A decade after the Global Malaria Eradication Program, El Salvador had the highest burden of malaria in Mesoamerica, with approximately 20% due to Plasmodium falciparum . A resurgence of malaria in the 1970s led El Salvador to alter its national malaria control strategy. By 1995, El Salvador recorded its last autochthonous P. falciparum case with fewer than 20 Plasmodium vivax cases annually since 2011. By contrast, its immediate neighbors continue to have the highest incidences of malaria in the region. We reviewed and evaluated the policies and interventions implemented by the Salvadoran National Malaria Program that likely contributed to this progress toward malaria elimination. Decentralization of the malaria program, early regional stratification by risk, and data-driven stratum-specific actions resulted in the timely and targeted allocation of resources for vector control, surveillance, case detection, and treatment. Weekly reporting by health workers and volunteer collaborators-distributed throughout the country by strata and informed via the national surveillance system-enabled local malaria teams to provide rapid, adaptive, and focalized program actions. Sustained investments in surveillance and response have led to a dramatic reduction in local transmission, with most current malaria cases in El Salvador due to importation from neighboring countries. Additional support for systematic elimination efforts in neighboring countries would benefit the region and may be needed for El Salvador to achieve and maintain malaria elimination. El Salvador's experience provides a relevant case study that can guide the application of similar strategies in other countries committed to malaria elimination.

PARACHUTING CATS AND CRUSHED EGGS The Controversy Over the Use of DDT to Control Malaria

PubMed Central

2008-01-01

The use of DDT to control malaria has been a contentious practice for decades. This controversy centers on concerns over the ecological harm caused by DDT relative to the gains in public health from its use to prevent malaria. Given the World Health Organization's recent policy decisions concerning the use of DDT to control malaria, it is worth reviewing the historical context of DDT use. Ecological concerns focused on evidence that DDT ingestion by predatory birds resulted in eggs with shells so thin they were crushed by adult birds. In addition, DDT spraying to control malaria allegedly resulted in cats being poisoned in some areas, which led to increased rodent populations and, in turn, the parachuting of cats into the highlands of the island of Borneo to kill the rodents, a story that influenced the decision to ban DDT spraying. I focus on this story with the intention of grounding the current debate on lessons from the past. PMID:18799776

To Live Like a Pig and Die Like a Dog: Environmental Implications for World War I in East Africa

DTIC Science & Technology

2009-12-03

held decisive advantages including greater numbers of troops, more robust logistics, and unchallenged control of the sea lines of communications...The Center for Disease Control defines malaria as “a serious and sometimes fatal disease caused by a parasite that commonly infects a certain type of...malaria parasites that can infect humans, Plasmodium falciparum remains indigenous to east 32 Center for Disease Control, “Malaria Home > Frequently

Estimation of effectiveness of interventions for malaria control in pregnancy using the screening method.

PubMed

Msyamboza, K; Senga, E; Tetteh-Ashong, E; Kazembe, P; Brabin, B J

2007-04-01

The evaluation of the effectiveness of antimalarial drugs and bed net use in pregnant women is an important aspect of monitoring and surveillance of malaria control in pregnancy. In principle the screening method for assessing vaccine efficacy can be applied in non-vaccine settings for assessing interventions for malaria control in pregnancy. In this analysis field data on the proportion of placental malaria cases treated with two doses of sulphadoxine-pyrimethamine (SP) and the uptake of two doses of SP in the antenatal clinic was used in a case-coverage method to assess the protective effectiveness (PE) of intermittent preventive treatment with SP for malaria control in pregnancy. PE was assessed using placental malaria, low birthweight and maternal anaemia at delivery as outcome variables. The method was also applied to an evaluation of the protective effectiveness of self-reported use of impregnated bed nets (ITNs). Effectiveness was highest for reduction of low birthweight in multigravidae (87.2%, 95% CI, 83.2-91.3%). PE was lower for placental malaria (61.6% primigravidae, 28.5% multigravidae), and maternal anaemia (Hb < 8.0 g/dl, 37.8% primigravidae, 29.6% multigravidae). Estimates for PE of self-reported use of ITNs gave values for all three outcome parameters that were much lower than for SP use. For women of all parties effectiveness estimates for reduction of low birthweight were 22% (95% CI, 17.7-26.4), prevention of placental malaria (all types) 7.1% (95% CI, 4.4-9.8), prevention of active placental infection 38.9% (95% CI, 27.4-50.4), and for maternal anaemia 8.8% (95% CI, 0-20.0). The case-coverage method could provide a useful and practical approach to routine monitoring and evaluation of drug interventions to control malaria in pregnancy and has potentially wide applications. Effectiveness estimates related to reported ITN use in pregnancy may be less reliable. The method should be further evaluated using currently available data sets.

Malaria Molecular Epidemiology: Lessons from the International Centers of Excellence for Malaria Research Network.

PubMed

Escalante, Ananias A; Ferreira, Marcelo U; Vinetz, Joseph M; Volkman, Sarah K; Cui, Liwang; Gamboa, Dionicia; Krogstad, Donald J; Barry, Alyssa E; Carlton, Jane M; van Eijk, Anna Maria; Pradhan, Khageswar; Mueller, Ivo; Greenhouse, Bryan; Pacheco, M Andreina; Vallejo, Andres F; Herrera, Socrates; Felger, Ingrid

2015-09-01

Molecular epidemiology leverages genetic information to study the risk factors that affect the frequency and distribution of malaria cases. This article describes molecular epidemiologic investigations currently being carried out by the International Centers of Excellence for Malaria Research (ICEMR) network in a variety of malaria-endemic settings. First, we discuss various novel approaches to understand malaria incidence and gametocytemia, focusing on Plasmodium falciparum and Plasmodium vivax. Second, we describe and compare different parasite genotyping methods commonly used in malaria epidemiology and population genetics. Finally, we discuss potential applications of molecular epidemiological tools and methods toward malaria control and elimination efforts. © The American Society of Tropical Medicine and Hygiene.

Synergistic and antagonistic interactions between bednets and vaccines in the control of malaria.

PubMed

Artzy-Randrup, Yael; Dobson, Andrew P; Pascual, Mercedes

2015-03-10

It is extremely likely that the malaria vaccines currently in development will be used in conjunction with treated bednets and other forms of malaria control. The interaction of different intervention methods is at present poorly understood in a disease such as malaria where immunity is more complex than for other pathogens that have been successfully controlled by vaccination. Here we develop a general mathematical model of malaria transmission to examine the interaction between vaccination and bednets. Counterintuitively, we find that the frailty of malaria immunity will potentially cause both synergistic and antagonistic interactions between vaccination and the use of bednets. We explore the conditions that create these tensions, and outline strategies that minimize their detrimental impact. Our analysis specifically considers the three leading vaccine classes currently in development: preerythrocytic (PEV), blood stage (BSV), and transmission blocking (TBV). We find that the combination of BSV with treated bednets can lead to increased morbidity with no added value in terms of elimination; the interaction is clearly antagonistic. In contrast, there is strong synergy between PEV and treated bednets that may facilitate elimination, although transient stages are likely to increase morbidity. The combination of TBV with treated bednets is synergistic, lowering both morbidity and elimination thresholds. Our results suggest that vaccines will not provide a straightforward solution to malaria control, and that future programs need to consider the synergistic and antagonistic interactions between vaccines and treated bednets.

Insecticide-treated nets provide protection against malaria to children in an area of insecticide resistance in Southern Benin.

PubMed

Bradley, John; Ogouyèmi-Hounto, Aurore; Cornélie, Sylvie; Fassinou, Jacob; de Tove, Yolande Sissinto Savi; Adéothy, Adicath Adéola; Tokponnon, Filémon T; Makoutode, Patrick; Adechoubou, Alioun; Legba, Thibaut; Houansou, Telesphore; Kinde-Gazard, Dorothée; Akogbeto, Martin C; Massougbodji, Achille; Knox, Tessa Bellamy; Donnelly, Martin; Kleinschmidt, Immo

2017-05-26

Malaria control is heavily reliant on insecticides, especially pyrethroids. Resistance of mosquitoes to insecticides may threaten the effectiveness of insecticide-based vector control and lead to a resurgence of malaria in Africa. In 21 villages in Southern Benin with high levels of insecticide resistance, the resistance status of local vectors was measured at the same time as the prevalence of malaria infection in resident children. Children who used LLINs had lower levels of malaria infection [odds ratio = 0.76 (95% CI 0.59, 0.98, p = 0.033)]. There was no evidence that the effectiveness of nets was different in high and low resistance locations (p = 0.513). There was no association between village level resistance and village level malaria prevalence (p = 0.999). LLINs continue to offer individual protection against malaria infection in an area of high resistance. Insecticide resistance is not a reason to stop efforts to increase coverage of LLINs in Africa.

Controlling Malaria Using Livestock-Based Interventions: A One Health Approach

PubMed Central

Franco, Ana O.; Gomes, M. Gabriela M.; Rowland, Mark; Coleman, Paul G.

2014-01-01

Where malaria is transmitted by zoophilic vectors, two types of malaria control strategies have been proposed based on animals: using livestock to divert vector biting from people (zooprophylaxis) or as baits to attract vectors to insecticide sources (insecticide-treated livestock). Opposing findings have been obtained on malaria zooprophylaxis, and despite the success of an insecticide-treated livestock trial in Pakistan, where malaria vectors are highly zoophilic, its effectiveness is yet to be formally tested in Africa where vectors are more anthropophilic. This study aims to clarify the different effects of livestock on malaria and to understand under what circumstances livestock-based interventions could play a role in malaria control programmes. This was explored by developing a mathematical model and combining it with data from Pakistan and Ethiopia. Consistent with previous work, a zooprophylactic effect of untreated livestock is predicted in two situations: if vector population density does not increase with livestock introduction, or if livestock numbers and availability to vectors are sufficiently high such that the increase in vector density is counteracted by the diversion of bites from humans to animals. Although, as expected, insecticide-treatment of livestock is predicted to be more beneficial in settings with highly zoophilic vectors, like South Asia, we find that the intervention could also considerably decrease malaria transmission in regions with more anthropophilic vectors, like Anopheles arabiensis in Africa, under specific circumstances: high treatment coverage of the livestock population, using a product with stronger or longer lasting insecticidal effect than in the Pakistan trial, and with small (ideally null) repellency effect, or if increasing the attractiveness of treated livestock to malaria vectors. The results suggest these are the most appropriate conditions for field testing insecticide-treated livestock in an Africa region with moderately zoophilic vectors, where this intervention could contribute to the integrated control of malaria and livestock diseases. PMID:25050703

Patent Medicine Sellers: How Can They Help Control Childhood Malaria?

PubMed Central

Akuse, Rosamund M.; Eseigbe, Edwin E.; Ahmed, Abubakar; Brieger, William R.

2010-01-01

Roll Back Malaria Initiative encourages participation of private health providers in malaria control because mothers seek care for sick children from them. This study investigated Patent Medicine Sellers (PMS) management of presumptive malaria in children in order to identify how they can assist malaria control. A cross-sectional survey of 491 PMS in Kaduna, Nigeria, was done using interviews and observation of shop activities. Most (80%) customers bought drugs without prescriptions. Only 29.5% were given instructions about doses. Between 40–100% doses of recommended antimalarials were incorrect. Some (22%) PMS did not ask questions about illness for which they were consulted. Most children treated in shops received injections. PMS facilitate homecare but have deficiencies in knowledge and practice. Interventions must focus on training them to accurately determine doses, give advice about drug administration, use oral medication, and ask about illness. Training should be made a prerequisite for registering and reregistering shops. PMID:22332020

Encouraging impact following 2.5 years of reinforced malaria control interventions in a hyperendemic region of the Republic of Guinea.

PubMed

Tiffany, Amanda; Moundekeno, Faya Pascal; Traoré, Alexis; Haile, Melat; Sterk, Esther; Guilavogui, Timothée; Genton, Blaise; Serafini, Micaela; Grais, Rebecca F

2016-05-28

Malaria is one of the principal causes of morbidity and mortality in the Republic of Guinea, particularly in the highly endemic regions. To assist in malaria control efforts, a multi-component malaria control intervention was implemented in the hyperendemic region of Guéckédou Prefecture. The coverage of the intervention and its impact on malaria parasite prevalence were assessed. Five cross-sectional surveys using cluster-based sampling and stratified by area were conducted from 2011 to 2013 in three sous-préfectures of Guéckédou Préfecture that received the intervention: Guéckédou City, Tékoulo and Guendembou in addition to one comparison sous-préfecture that did not receive the intervention, Koundou. Surveys were repeated every 6 months, corresponding with the dry and rainy seasons. Rapid diagnostic tests (RDT) were used to diagnose malaria infection. In each selected household, bed net use and ownership were assessed. A total of 35,123 individuals participated in the surveys. Malaria parasite prevalence declined in all intervention sous-préfectures from 2011 to 2013 (56.4-45.9 % in Guéckédou City, 64.9-54.1 % in Tékoulo and 69.4-56.9 % in Guendembou) while increasing in the comparison sous-préfecture (64.5-69 %). It was consistently higher in children 5-14 years of age followed by those 1-59 months and ≥15 years. Indicators of intervention coverage, the proportion of households reporting ownership of at least one bed net and the proportion of survey participants with fever who received treatment from a health facility or community health worker also increased significantly in the intervention areas. Implementation of the multi-component malaria control intervention significantly reduced the prevalence of malaria in the sous-préfectures of intervention while also increasing the coverage of bed nets. However, malaria prevalence remains unacceptably high and disproportionately affects children <15 years of age. In such situations additional vector control interventions and age specific interventions should be considered.

Spatial targeting of interventions against malaria.

PubMed Central

Carter, R.; Mendis, K. N.; Roberts, D.

2000-01-01

Malaria transmission is strongly associated with location. This association has two main features. First, the disease is focused around specific mosquito breeding sites and can normally be transmitted only within certain distances from them: in Africa these are typically between a few hundred metres and a kilometre and rarely exceed 2-3 kilometres. Second, there is a marked clustering of persons with malaria parasites and clinical symptoms at particular sites, usually households. In localities of low endemicity the level of malaria risk or case incidence may vary widely between households because the specific characteristics of houses and their locations affect contact between humans and vectors. Where endemicity is high, differences in human/vector contact rates between different households may have less effect on malaria case incidences. This is because superinfection and exposure-acquired immunity blur the proportional relationship between inoculation rates and case incidences. Accurate information on the distribution of malaria on the ground permits interventions to be targeted towards the foci of transmission and the locations and households of high malaria risk within them. Such targeting greatly increases the effectiveness of control measures. On the other hand, the inadvertent exclusion of these locations causes potentially effective control measures to fail. The computerized mapping and management of location data in geographical information systems should greatly assist the targeting of interventions against malaria at the focal and household levels, leading to improved effectiveness and cost-effectiveness of control. PMID:11196487

Spatial targeting of interventions against malaria.

PubMed

Carter, R; Mendis, K N; Roberts, D

2000-01-01

Malaria transmission is strongly associated with location. This association has two main features. First, the disease is focused around specific mosquito breeding sites and can normally be transmitted only within certain distances from them: in Africa these are typically between a few hundred metres and a kilometre and rarely exceed 2-3 kilometres. Second, there is a marked clustering of persons with malaria parasites and clinical symptoms at particular sites, usually households. In localities of low endemicity the level of malaria risk or case incidence may vary widely between households because the specific characteristics of houses and their locations affect contact between humans and vectors. Where endemicity is high, differences in human/vector contact rates between different households may have less effect on malaria case incidences. This is because superinfection and exposure-acquired immunity blur the proportional relationship between inoculation rates and case incidences. Accurate information on the distribution of malaria on the ground permits interventions to be targeted towards the foci of transmission and the locations and households of high malaria risk within them. Such targeting greatly increases the effectiveness of control measures. On the other hand, the inadvertent exclusion of these locations causes potentially effective control measures to fail. The computerized mapping and management of location data in geographical information systems should greatly assist the targeting of interventions against malaria at the focal and household levels, leading to improved effectiveness and cost-effectiveness of control.

Malaria epidemiological research in the Republic of Congo.

PubMed

Koukouikila-Koussounda, Felix; Ntoumi, Francine

2016-12-23

Reliable and comprehensive information on the burden of malaria is critical for guiding national and international efforts in malaria control. The purpose of this review is to provide an overview of published data and available information on malaria resulting from field studies/investigations conducted in the Republic of Congo (RoC) from 1992 to 2015, as baseline for assisting public health authorities and researchers to define future research priorities as well as interventions. This review considers data from peer-reviewed articles and information from the National Malaria Control Programme reports, based on field investigations or samples collected from 1992 to 2015. Peer-reviewed papers were searched throughout online bibliographic databases PubMed, HINARI and Google Scholar using the following terms: "malaria", "Congo", "Brazzaville", "prevalence", "antimalarial", "efficacy", "falciparum", "genetic", "diversity". Original articles and reviews were included and selection of relevant papers was made. Twenty-eight published articles were included in this review and two additional records from the National Malaria Control Programme were also considered. The majority of studies were conducted in Brazzaville and Pointe-Noire. The present systematic review reveals that number of studies have been conducted in the RoC with regard to malaria. However, their results cannot formally be generalized at the country level. This suggests a need for implementing regular multisite investigations and surveys that may be representative of the country, calling for the support and lead of the Ministry of Health.

Malaria vaccines: past, present and future.

PubMed

von Seidlein, Lorenz; Bejon, Philip

2013-12-01

The currently available malaria control tools have allowed malaria elimination in many regions but there remain many regions where malaria control has made little progress. A safe and protective malaria vaccine would be a huge asset for malaria control. Despite the many challenges, efforts continue to design and evaluate malaria vaccine candidates. These candidates target different stages in the life cycle of Plasmodia. The most advanced vaccine candidates target the pre-erythrocytic stages in the life cycle of the parasite and include RTS,S/AS01, which has progressed through clinical development to the stage that it may be licensed in 2015. Attenuated whole-parasite vaccine candidates are highly protective, but there are challenges to manufacture and to administration. Cellular immunity is targeted by the prime-boost approach. Priming vectors trigger only modest responses but these are focused on the recombinant antigen. Boosting vectors trigger strong but broad non-specific responses. The heterologous sequence produces strong immunological responses to the recombinant antigen. Candidates that target the blood stages of the parasite have to result in an immune response that is more effective than the response to an infection to abort or control the infection of merozoites and hence disease. Finally, the sexual stages of the parasite offer another target for vaccine development, which would prevent the transmission of malaria. Today it seems unlikely that any candidate targeting a single antigen will provide complete protection against an organism of the complexity of Plasmodium. A systematic search for vaccine targets and combinations of antigens may be a more promising approach.

Methodological Considerations for Use of Routine Health Information System Data to Evaluate Malaria Program Impact in an Era of Declining Malaria Transmission

PubMed Central

Ashton, Ruth A.; Bennett, Adam; Yukich, Joshua; Bhattarai, Achuyt; Keating, Joseph; Eisele, Thomas P.

2017-01-01

Abstract. Coverage of malaria control interventions is increasing dramatically across endemic countries. Evaluating the impact of malaria control programs and specific interventions on health indicators is essential to enable countries to select the most effective and appropriate combination of tools to accelerate progress or proceed toward malaria elimination. When key malaria interventions have been proven effective under controlled settings, further evaluations of the impact of the intervention using randomized approaches may not be appropriate or ethical. Alternatives to randomized controlled trials are therefore required for rigorous evaluation under conditions of routine program delivery. Routine health management information system (HMIS) data are a potentially rich source of data for impact evaluation, but have been underused in impact evaluation due to concerns over internal validity, completeness, and potential bias in estimates of program or intervention impact. A range of methodologies were identified that have been used for impact evaluations with malaria outcome indicators generated from HMIS data. Methods used to maximize internal validity of HMIS data are presented, together with recommendations on reducing bias in impact estimates. Interrupted time series and dose-response analyses are proposed as the strongest quasi-experimental impact evaluation designs for analysis of malaria outcome indicators from routine HMIS data. Interrupted time series analysis compares the outcome trend and level before and after the introduction of an intervention, set of interventions or program. The dose-response national platform approach explores associations between intervention coverage or program intensity and the outcome at a subnational (district or health facility catchment) level. PMID:28990915

Studying relationships between environment and malaria incidence in Camopi (French Guiana) through the objective selection of buffer-based landscape characterisations

PubMed Central

2011-01-01

Background Malaria remains a major health problem in French Guiana, with a mean of 3800 cases each year. A previous study in Camopi, an Amerindian village on the Oyapock River, highlighted the major contribution of environmental features to the incidence of malaria attacks. We propose a method for the objective selection of the best multivariate peridomestic landscape characterisation that maximises the chances of identifying relationships between environmental features and malaria incidence, statistically significant and meaningful from an epidemiological point of view. Methods A land-cover map, the hydrological network and the geolocalised inhabited houses were used to characterise the peridomestic landscape in eleven discoid buffers with radii of 50, 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000 metres. Buffer-based landscape characterisations were first compared in terms of their capacity to discriminate between sites within the geographic space and of their effective multidimensionality in variable space. The Akaike information criterion (AIC) was then used to select the landscape model best explaining the incidences of P. vivax and P. falciparum malaria. Finally, we calculated Pearson correlation coefficients for the relationships between environmental variables and malaria incidence, by species, for the more relevant buffers. Results The optimal buffers for environmental characterisation had radii of 100 m around houses for P. vivax and 400 m around houses for P. falciparum. The incidence of P. falciparum malaria seemed to be more strongly linked to environmental features than that of P. vivax malaria, within these buffers. The incidence of P. falciparum malaria in children was strongly correlated with proportions of bare soil (r = -0.69), land under high vegetation (r = 0.68) and primary forest (r = 0.54), landscape division (r = 0.48) and the number of inhabited houses (r = -0.60). The incidence of P. vivax malaria was associated only with landscape division (r = 0.49). Conclusions The proposed methodology provides a simple and general framework for objective characterisation of the landscape to account for field observations. The use of this method enabled us to identify different optimal observation horizons around houses, depending on the Plasmodium species considered, and to demonstrate significant correlations between environmental features and the incidence of malaria. PMID:22151738

Studying relationships between environment and malaria incidence in Camopi (French Guiana) through the objective selection of buffer-based landscape characterisations.

PubMed

Stefani, Aurélia; Roux, Emmanuel; Fotsing, Jean-Marie; Carme, Bernard

2011-12-13

Malaria remains a major health problem in French Guiana, with a mean of 3800 cases each year. A previous study in Camopi, an Amerindian village on the Oyapock River, highlighted the major contribution of environmental features to the incidence of malaria attacks. We propose a method for the objective selection of the best multivariate peridomestic landscape characterisation that maximises the chances of identifying relationships between environmental features and malaria incidence, statistically significant and meaningful from an epidemiological point of view. A land-cover map, the hydrological network and the geolocalised inhabited houses were used to characterise the peridomestic landscape in eleven discoid buffers with radii of 50, 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000 metres. Buffer-based landscape characterisations were first compared in terms of their capacity to discriminate between sites within the geographic space and of their effective multidimensionality in variable space. The Akaike information criterion (AIC) was then used to select the landscape model best explaining the incidences of P. vivax and P. falciparum malaria. Finally, we calculated Pearson correlation coefficients for the relationships between environmental variables and malaria incidence, by species, for the more relevant buffers. The optimal buffers for environmental characterisation had radii of 100 m around houses for P. vivax and 400 m around houses for P. falciparum. The incidence of P. falciparum malaria seemed to be more strongly linked to environmental features than that of P. vivax malaria, within these buffers. The incidence of P. falciparum malaria in children was strongly correlated with proportions of bare soil (r = -0.69), land under high vegetation (r = 0.68) and primary forest (r = 0.54), landscape division (r = 0.48) and the number of inhabited houses (r = -0.60). The incidence of P. vivax malaria was associated only with landscape division (r = 0.49). The proposed methodology provides a simple and general framework for objective characterisation of the landscape to account for field observations. The use of this method enabled us to identify different optimal observation horizons around houses, depending on the Plasmodium species considered, and to demonstrate significant correlations between environmental features and the incidence of malaria. © 2011 Stefani et al; licensee BioMed Central Ltd.

The potential impact of integrated malaria transmission control on entomologic inoculation rate in highly endemic areas.

PubMed

Killeen, G F; McKenzie, F E; Foy, B D; Schieffelin, C; Billingsley, P F; Beier, J C

2000-05-01

We have used a relatively simple but accurate model for predicting the impact of integrated transmission control on the malaria entomologic inoculation rate (EIR) at four endemic sites from across sub-Saharan Africa and the southwest Pacific. The simulated campaign incorporated modestly effective vaccine coverage, bed net use, and larval control. The results indicate that such campaigns would reduce EIRs at all four sites by 30- to 50-fold. Even without the vaccine, 15- to 25-fold reductions of EIR were predicted, implying that integrated control with a few modestly effective tools can meaningfully reduce malaria transmission in a range of endemic settings. The model accurately predicts the effects of bed nets and indoor spraying and demonstrates that they are the most effective tools available for reducing EIR. However, the impact of domestic adult vector control is amplified by measures for reducing the rate of emergence of vectors or the level of infectiousness of the human reservoir. We conclude that available tools, including currently neglected methods for larval control, can reduce malaria transmission intensity enough to alleviate mortality. Integrated control programs should be implemented to the fullest extent possible, even in areas of intense transmission, using simple models as decision-making tools. However, we also conclude that to eliminate malaria in many areas of intense transmission is beyond the scope of methods which developing nations can currently afford. New, cost-effective, practical tools are needed if malaria is ever to be eliminated from highly endemic areas.

Conquering the intolerable burden of malaria: what's new, what's needed: a summary.

PubMed

Breman, Joel G; Alilio, Martin S; Mills, Anne

2004-08-01

Each year, up to three million deaths due to malaria and close to five billion episodes of clinical illness possibly meriting antimalarial therapy occur throughout the world, with Africa having more than 90% of this burden. Almost 3% of disability adjusted life years are due to malaria mortality globally, 10% in Africa. New information is presented in this supplement on malaria-related perinatal mortality, occurrence of human immunodeficiency virus in pregnancy, undernutrition, and neurologic, cognitive, and developmental sequelae. The entomologic determinants of transmission and uses of modeling for program planning and disease prediction and prevention are discussed. New data are presented from the Democratic Republic of the Congo, Tanzania, Ethiopia, and Zimbabwe on the increasing urban malaria problem and on epidemic malaria. Between 6% and 28% of the malaria burden may occur in cities, which comprise less than 2% of the African surface. Macroeconomic projections show that the costs are far greater than the costs of individual cases, with a substantial deleterious impact of malaria on schooling of patients, external investments into endemic countries, and tourism. Poor populations are at greatest risk; 58% of the cases occur in the poorest 20% of the world's population and these patients receive the worst care and have catastrophic economic consequences from their illness. This social vulnerability requires better understanding for improving deployment, access, quality, and use of effective interventions. Studies from Ghana and elsewhere indicate that for every patient with febrile illness assumed to be malaria seen in health facilities, 4-5 episodes occur in the community. Effective actions for malaria control mandate rational public policies; market forces, which often drive sales and use of drugs and other interventions, are unlikely to guarantee their use. Artemisinin-based combination therapy (ACT) for malaria is rapidly gaining acceptance as an effective approach for countering the spread and intensity of Plasmodium falciparum resistance to chloroquine, sulfadoxine/pyrimethamine, and other antimalarial drugs. Although costly, ACT ($1.20-2.50 per adult treatment) becomes more cost-effective as resistance to alternative drugs increases; early use of ACT may delay development of resistance to these drugs and prevent the medical toll associated with use of ineffective drugs. The burden of malaria in one district in Tanzania has not decreased since the primary health care approach replaced the vertical malaria control efforts of the 1960s. Despite decentralization, this situation resulted, in part, from weak district management capacity, poor coordination, inadequate monitoring, and lack of training of key staff. Experience in the Solomon Islands showed that spraying with DDT, use of insecticide-treated bed nets (ITNs), and health education were all associated with disease reduction. The use of nets permitted a reduction in DDT spraying, but could not replace it without an increased malaria incidence. Baseline data and reliable monitoring of key outcome indicators are needed to measure whether the ambitious goals for the control of malaria and other diseases has occurred. Such systems are being used for evidence-based decision making in Tanzania and several other countries. Baseline cluster sampling surveys in several countries across Africa indicate that only 53% of the children with febrile illness in malarious areas are being treated; chloroquine (CQ) is used 84% of the time, even where the drug may be ineffective. Insecticide-treated bed nets were used only 2% of the time by children less than five years of age. Progress in malaria vaccine research has been substantial over the past five years; 35 candidate malaria vaccines are in development, many of which are in clinical trials. Development of new vaccines and drugs has been the result of increased investments and formation of public-private partnerships. Before malaria vaccine becomes deployed, consideration must be given to disease burden, cost-effectiveness, financing, delivery systems, and approval by regulatory agencies. Key to evaluation of vaccine effectiveness will be collection and prompt analysis of epidemiologic information. Training of persons in every aspect of malaria research and control is essential for programs to succeed. The Multilateral Initiative on Malaria (MIM) is actively promoting research capacity strengthening and has established networks of institutions and scientists throughout the African continent, most of whom are now linked by modern information-sharing networks. Evidence over the past century is that successful control malaria programs have been linked to strong research activities. To ensure effective coordination and cooperation between the growing number of research and control coalitions forming in support of malaria activities, an umbrella group is needed. With continued support for scientists and control workers globally, particularly in low-income malarious countries, the long-deferred dream of malaria elimination can become a reality. Copyright 2004 The American Society of Tropical Medicine and Hygiene

Changing climate and the altitudinal range of avian malaria in the Hawaiian Islands: an ongoing conservation crisis on the island of Kaua'i

USGS Publications Warehouse

Atkinson, Carter T.; Utzurrum, Ruth B.; LaPointe, Dennis A.; Camp, Richard J.; Crampton, Lisa H.; Foster, Jeffrey T.; Giambelluca, Thomas W.

2014-01-01

Transmission of avian malaria in the Hawaiian Islands varies across altitudinal gradients and is greatest at elevations below 1500 m where both temperature and moisture are favorable for the sole mosquito vector, Culex quinquefasciatus, and extrinsic sporogonic development of the parasite, Plasmodium relictum. Potential consequences of global warming on this system have been recognized for over a decade with concerns that increases in mean temperatures could lead to expansion of malaria into habitats where cool temperatures currently limit transmission to highly susceptible endemic forest birds. Recent declines in two endangered species on the island of Kaua'i, the ‘Akikiki (Oreomystis bairdi) and ‘Akeke'e (Loxops caeruleirostris), and retreat of more common native honeycreepers to the last remaining high elevation habitat on the Alaka'i Plateau suggest that predicted changes in disease transmission may be occurring. We compared prevalence of malarial infections in forest birds that were sampled at three locations on the Plateau during 1994–1997 and again during 2007–2013, and also evaluated changes in the occurrence of mosquito larvae in available aquatic habitats during the same time periods. Prevalence of infection increased significantly at the lower (1100 m, 10.3% to 28.2%), middle (1250 m, 8.4% to 12.2%), and upper ends of the Plateau (1350 m, 2.0% to 19.3%). A concurrent increase in detections of Culex larvae in aquatic habitats associated with stream margins indicates that populations of the vector are also increasing. These increases are at least in part due to local transmission because overall prevalence in Kaua'i ‘Elepaio (Chasiempis sclateri), a sedentary native species, has increased from 17.2% to 27.0%. Increasing mean air temperatures, declining precipitation, and changes in streamflow that have taken place over the past 20 years are creating environmental conditions throughout major portions of the Alaka'i Plateau that support increased transmission of avian malaria.

Changing climate and the altitudinal range of avian malaria in the Hawaiian Islands - an ongoing conservation crisis on the island of Kaua'i.

PubMed

Atkinson, Carter T; Utzurrum, Ruth B; Lapointe, Dennis A; Camp, Richard J; Crampton, Lisa H; Foster, Jeffrey T; Giambelluca, Thomas W

2014-08-01

Transmission of avian malaria in the Hawaiian Islands varies across altitudinal gradients and is greatest at elevations below 1500 m where both temperature and moisture are favorable for the sole mosquito vector, Culex quinquefasciatus, and extrinsic sporogonic development of the parasite, Plasmodium relictum. Potential consequences of global warming on this system have been recognized for over a decade with concerns that increases in mean temperatures could lead to expansion of malaria into habitats where cool temperatures currently limit transmission to highly susceptible endemic forest birds. Recent declines in two endangered species on the island of Kaua'i, the 'Akikiki (Oreomystis bairdi) and 'Akeke'e (Loxops caeruleirostris), and retreat of more common native honeycreepers to the last remaining high elevation habitat on the Alaka'i Plateau suggest that predicted changes in disease transmission may be occurring. We compared prevalence of malarial infections in forest birds that were sampled at three locations on the Plateau during 1994-1997 and again during 2007-2013, and also evaluated changes in the occurrence of mosquito larvae in available aquatic habitats during the same time periods. Prevalence of infection increased significantly at the lower (1100 m, 10.3% to 28.2%), middle (1250 m, 8.4% to 12.2%), and upper ends of the Plateau (1350 m, 2.0% to 19.3%). A concurrent increase in detections of Culex larvae in aquatic habitats associated with stream margins indicates that populations of the vector are also increasing. These increases are at least in part due to local transmission because overall prevalence in Kaua'i 'Elepaio (Chasiempis sclateri), a sedentary native species, has increased from 17.2% to 27.0%. Increasing mean air temperatures, declining precipitation, and changes in streamflow that have taken place over the past 20 years are creating environmental conditions throughout major portions of the Alaka'i Plateau that support increased transmission of avian malaria. © 2014 John Wiley & Sons Ltd.

Impact of Sickle Cell Trait and Naturally Acquired Immunity on Uncomplicated Malaria after Controlled Human Malaria Infection in Adults in Gabon.

PubMed

Lell, Bertrand; Mordmüller, Benjamin; Dejon Agobe, Jean-Claude; Honkpehedji, Josiane; Zinsou, Jeannot; Mengue, Juliana Boex; Loembe, Marguerite Massinga; Adegnika, Ayola Akim; Held, Jana; Lalremruata, Albert; Nguyen, The Trong; Esen, Meral; Kc, Natasha; Ruben, Adam J; Chakravarty, Sumana; Lee Sim, B Kim; Billingsley, Peter F; James, Eric R; Richie, Thomas L; Hoffman, Stephen L; Kremsner, Peter G

2018-02-01

Controlled human malaria infection (CHMI) by direct venous inoculation (DVI) with 3,200 cryopreserved Plasmodium falciparum sporozoites (PfSPZ) consistently leads to parasitemia and malaria symptoms in malaria-naive adults. We used CHMI by DVI to investigate infection rates, parasite kinetics, and malaria symptoms in lifelong malaria-exposed (semi-immune) Gabonese adults with and without sickle cell trait. Eleven semi-immune Gabonese with normal hemoglobin (IA), nine with sickle cell trait (IS), and five nonimmune European controls with normal hemoglobin (NI) received 3,200 PfSPZ by DVI and were followed 28 days for parasitemia by thick blood smear (TBS) and quantitative polymerase chain reaction (qPCR) and for malaria symptoms. End points were time to parasitemia and parasitemia plus symptoms. PfSPZ Challenge was well tolerated and safe. Five of the five (100%) NI, 7/11 (64%) IA, and 5/9 (56%) IS volunteers developed parasitemia by TBS, and 5/5 (100%) NI, 9/11 (82%) IA, and 7/9 (78%) IS by qPCR, respectively. The time to parasitemia by TBS was longer in IA (geometric mean 16.9 days) and IS (19.1 days) than in NA (12.6 days) volunteers ( P = 0.016, 0.021, respectively). Five of the five, 6/9, and 1/7 volunteers with parasitemia developed symptoms ( P = 0.003, NI versus IS). Naturally adaptive immunity (NAI) to malaria significantly prolonged the time to parasitemia. Sickle cell trait seemed to prolong it further. NAI plus sickle cell trait, but not NAI alone, significantly reduced symptom rate. Twenty percent (4/20) semi-immunes demonstrated sterile protective immunity. Standardized CHMI with PfSPZ Challenge is a powerful tool for dissecting the impact of innate and naturally acquired adaptive immunity on malaria.

Control of malaria: a successful experience from Viet Nam.

PubMed Central

Hung, Le Q.; Vries, Peter J. de; Giao, Phan T.; Nam, Nguyen V.; Binh, Tran Q.; Chong, M. T.; Quoc, N. T. T. A.; Thanh, T. N.; Hung, L. N.; Kager, P. A.

2002-01-01

OBJECTIVE: To follow malaria prospectively in an ethnic minority commune in the south of Viet Nam with high malaria transmission and seasonal fluctuation, during malaria control interventions using insecticide-treated bednets (ITBNs) and early diagnosis and treatment (EDT) of symptomatic patients. METHODS: From 1994 onwards the following interventions were used: distribution of ITBNs to all households with biannual reimpregnation; construction of a health post and appointment of staff trained in microscopic diagnosis and treatment of malaria; regular supply of materials and drugs; annual cross-sectional malaria surveys with treatment of all parasitaemic subjects, and a programme of community involvement and health education. Surveys were held yearly at the end of the rainy season. During the surveys, demographic data were updated. Diagnosis and treatment of malaria were free of charge. Plasmodium falciparum infection was treated with artesunate and P. vivax infection with chloroquine plus primaquine. FINDINGS: The baseline survey in 1994 recorded 716 inhabitants. Of the children under 2 years of age, 37% were parasitaemic; 56% of children aged 2-10 years, and 35% of the remaining population were parasitaemic. P. falciparum accounted for 73-79% of these infections. The respective splenomegaly rates for the above-mentioned age groups were 20%, 56%, and 32%. In 1999, the proportion of parasitaemic subjects was 4%, 7% and 1%, respectively, of which P.falciparum contributed 56%. The splenomegaly rate was 0%, 5% and 2%, respectively. CONCLUSIONS: A combination of ITBNs and EDT, provided free of charge, complemented by annual diagnosis and treatment during malaria surveys and community involvement with health education successfully brought malaria under control. This approach could be applied to other regions in the south of Viet Nam and provides a sound basis for further studies in other areas with different epidemiological patterns of malaria. PMID:12219158

Malaria vaccine: the pros and cons.

PubMed

Saleh, J A; Yusuph, H; Zailani, S B; Aji, B

2010-01-01

Malaria is an important parasitic disease of humans caused by infection with a parasite of the genus Polasmodium and transmitted by female anopheles. Infection caused by P. falciparum is the most serious of all the other species (P. ovale, P. vivax and P. malariae) especially in terms of morbidity and mortality hence the reason why most of the research has been focussed on this species. The disease affects up to about 40 per cent of the world's population with around 300-500 million people currently infected and mainly in the tropics. It has a high morbidity and mortality especially in resource-poor tropical and subtropical regions with an economic fall of about US$ 12 billion annually in Africa alone. relevant literatures were reviewed from medical journals, library search and internet source. Other relevant websites like PATH, Malaria Vaccine Initiative and Global Fund were also visited to source for information. The key words employed were: malaria, vaccine, anopheles mosquito, insecticide treated bed-nets, pyrethroids and Plasmodium. several studies have underscored the need to develop an effective human malaria vaccine for the control and possible eradication of malaria across the globe with the view to reduce the morbidity and mortality associated with the disease, improve on the social and economic losses and also protect those at risk. It is very obvious that the need for effective human malaria vaccine is not only to serve those living in malaria endemic regions but also the non-immune travellers especially those travelling to malaria endemic areas; this would offer cost effective means of preventing the disease, reducing the morbidity and mortality associated with it in addition to closing the gap left by other control measures. It is very obvious that there is no single control measure known to be effective in the control of malaria, hence the need for combination of more than one method with the aim of achieving synergy in the total control and possible eradication of the disease. It suffices to say that despite the use of combination of more than one method (e.g., drugs treating patients, breaking the life cycle of the vector mosquito using larvicides, clearing swamps and other mosquito breeding sites), no much progress was made towards achieving this goal, hence the renewed interest especially with regards to vaccine development.

Community-based scheduled screening and treatment of malaria in pregnancy for improved maternal and infant health in The Gambia, Burkina Faso and Benin: study protocol for a randomized controlled trial.

PubMed

Scott, Susana; Mens, Petra F; Tinto, Halidou; Nahum, Alain; Ruizendaal, Esmée; Pagnoni, Franco; Grietens, Koen Peeters; Kendall, Lindsay; Bojang, Kalifa; Schallig, Henk; D'Alessandro, Umberto

2014-08-28

In sub-Saharan Africa, malaria continues to cause over 10,000 maternal deaths and 75,000 to 200,000 infant deaths. Successful control of malaria in pregnancy could save lives of mothers and babies and is an essential part of antenatal care in endemic areas. The primary objective is to determine the protective efficacy of community-scheduled screening and treatment (CSST) using community health workers (CHW) against the primary outcome of prevalence of placental malaria. The secondary objectives are to determine the protective efficacy of CSST on maternal anaemia, maternal peripheral infection, low birth weight, selection of sulfadoxine-pyrimethamine (SP) resistance markers, and on antenatal clinic (ANC) attendance and coverage of intermittent preventive treatment during pregnancy (IPTp-SP). This is a multi-centre cluster-randomised controlled trial involving three countries with varying malaria endemicity; low (The Gambia) versus high transmission (Burkina Faso and Benin), and varying degrees of SP resistance (high in Benin and moderate in Gambia and Burkina Faso). CHW and their related catchment population who are randomised into the intervention arm will receive specific training on community-based case management of malaria in pregnancy. All women in both study arms will be enrolled at their first ANC visits in their second trimester where they will receive their first dose of IPTp-SP. Thereafter, CHW in the intervention arm will perform scheduled monthly screening and treatment in the womens homes. At time of delivery, a placental biopsy will be collected from all women to determine placental malaria. At each contact point, filter paper and blood slides will be collected for detection of malaria infection and SP resistance markers. To reach successful global malaria control, there is an urgent need to access those at greatest risk of malaria infection. The project is designed to develop a low-cost intervention in pregnant women which will have an immediate impact on the malaria burden in resource-limited countries. This will be done by adding to the standard IPTp-SP delivered through the health facilities: an "extension" strategy to the communities in rural areas thus bringing health services closer to where women live. Current Controlled Trials: ISRCTN37259296 (5 July 2013), and clinicaltrials.gov: NCT01941264 (10 September 2013).

Factors affecting prevention and control of malaria among endemic areas of Gurage zone: an implication for malaria elimination in South Ethiopia, 2017.

PubMed

Girum, Tadele; Hailemikael, Gebremariam; Wondimu, Asegedech

2017-01-01

Globally malaria remains one of the most severe public health problems resulting in massive morbidity particularly in developing countries. Ethiopia as one of the sub-Saharan country it is highly endemic to malaria. It was noted that early detection and prompt treatment of malaria cases, selective vector control and epidemic prevention and control are the major strategies for malaria prevention and control; So far, a lot have been done and remarkable improvements were seen. However, in what extent the prevention strategy was running in the community and what factors are hindering the prevention strategy at community level was not well known in Ethiopia. Therefore this study aimed to assess measures taken to prevent malaria and associated factors among households in Gurage zone, south Ethiopia. Community based cross- sectional study was conducted in Gurage zone, southern Ethiopia . A total of 817 randomly selected households were included in the study. After checking for completeness the data was entered in to Epi info 7 and analyzed through SPSS (Statistical Package for Social Sciences) version 21. Descriptive summary was computed and presented by tables, graphs and figures. After checking for assumptions Bivariate analysis was run to look for the association between dependent and explanatory variables; and using variables which have p -value ≤0.25 binary logistic regression was fitted. Association was presented in Odds ratio with 95% confidence interval and significance determined at P -value less than 0.05. Goodness of fit of the final model checked by Hosmer and Lemshow test. Overall 496 (62%) of households practiced good measure of malaria prevention and control. Educated households (AOR = 2.15 (95% CI [1.21-4.67]), higher wealth index (AOR = 3.3 (95% CI [2.3-6.2]), iron corrugated house owners (AOR = 2.7 (95% CI [1.7-3.5]), who received ITN from HC (AOR = 3.6 (95% CI [1.7-4.5] and involved in malaria prevention campaign AOR = 2.6, (95% CI [1.8-3.6]) were independently and significantly determined the practice of malaria prevention measures. The practice of malaria prevention measures were at acceptable and comparable level to other national findings and standards. Further strengthening of the program is important.

Impact of Malaria Control on Mortality and Anemia among Tanzanian Children Less than Five Years of Age, 1999–2010

PubMed Central

Smithson, Paul; Florey, Lia; Salgado, S. Rene; Hershey, Christine L.; Masanja, Honorati; Bhattarai, Achuyt; Mwita, Alex; McElroy, Peter D.

2015-01-01

Background Mainland Tanzania scaled up multiple malaria control interventions between 1999 and 2010. We evaluated whether, and to what extent, reductions in all-cause under-five child mortality (U5CM) tracked with malaria control intensification during this period. Methods Four nationally representative household surveys permitted trend analysis for malaria intervention coverage, severe anemia (hemoglobin <8 g/dL) prevalence (SAP) among children 6–59 months, and U5CM rates stratified by background characteristics, age, and malaria endemicity. Prevalence of contextual factors (e.g., vaccination, nutrition) likely to influence U5CM were also assessed. Population attributable risk percentage (PAR%) estimates for malaria interventions and contextual factors that changed over time were used to estimate magnitude of impact on U5CM. Results Household ownership of insecticide-treated nets (ITNs) rose from near zero in 1999 to 64% (95% CI, 61.7–65.2) in 2010. Intermittent preventive treatment of malaria in pregnancy reached 26% (95% CI, 23.6–28.0) by 2010. Sulfadoxine-pyrimethamine replaced chloroquine in 2002 and artemisinin-based combination therapy was introduced in 2007. SAP among children 6–59 months declined 50% between 2005 (11.1%; 95% CI, 10.0–12.3%) and 2010 (5.5%; 95% CI, 4.7–6.4%) and U5CM declined by 45% between baseline (1995–9) and endpoint (2005–9), from 148 to 81 deaths/1000 live births, respectively. Mortality declined 55% among children 1–23 months of age in higher malaria endemicity areas. A large reduction in U5CM was attributable to ITNs (PAR% = 11) with other malaria interventions adding further gains. Multiple contextual factors also contributed to survival gains. Conclusion Marked declines in U5CM occurred in Tanzania between 1999 and 2010 with high impact from ITNs and ACTs. High-risk children (1–24 months of age in high malaria endemicity) experienced the greatest declines in mortality and SAP. Malaria control should remain a policy priority to sustain and further accelerate progress in child survival. PMID:26536354

Climate forcing and desert malaria: the effect of irrigation.

PubMed

Baeza, Andres; Bouma, Menno J; Dobson, Andy P; Dhiman, Ramesh; Srivastava, Harish C; Pascual, Mercedes

2011-07-14

Rainfall variability and associated remote sensing indices for vegetation are central to the development of early warning systems for epidemic malaria in arid regions. The considerable change in land-use practices resulting from increasing irrigation in recent decades raises important questions on concomitant change in malaria dynamics and its coupling to climate forcing. Here, the consequences of irrigation level for malaria epidemics are addressed with extensive time series data for confirmed Plasmodium falciparum monthly cases, spanning over two decades for five districts in north-west India. The work specifically focuses on the response of malaria epidemics to rainfall forcing and how this response is affected by increasing irrigation. Remote sensing data for the Normalized Difference Vegetation Index (NDVI) are used as an integrated measure of rainfall to examine correlation maps within the districts and at regional scales. The analyses specifically address whether irrigation has decreased the coupling between malaria incidence and climate variability, and whether this reflects (1) a breakdown of NDVI as a useful indicator of risk, (2) a weakening of rainfall forcing and a concomitant decrease in epidemic risk, or (3) an increase in the control of malaria transmission. The predictive power of NDVI is compared against that of rainfall, using simple linear models and wavelet analysis to study the association of NDVI and malaria variability in the time and in the frequency domain respectively. The results show that irrigation dampens the influence of climate forcing on the magnitude and frequency of malaria epidemics and, therefore, reduces their predictability. At low irrigation levels, this decoupling reflects a breakdown of local but not regional NDVI as an indicator of rainfall forcing. At higher levels of irrigation, the weakened role of climate variability may be compounded by increased levels of control; nevertheless this leads to no significant decrease in the actual risk of disease. This implies that irrigation can lead to more endemic conditions for malaria, creating the potential for unexpectedly large epidemics in response to excess rainfall if these climatic events coincide with a relaxation of control over time. The implications of our findings for control policies of epidemic malaria in arid regions are discussed.

Malaria Control Interventions Contributed to Declines in Malaria Parasitemia, Severe Anemia, and All-Cause Mortality in Children Less Than 5 Years of Age in Malawi, 2000–2010

PubMed Central

Hershey, Christine L.; Florey, Lia S.; Ali, Doreen; Bennett, Adam; Luhanga, Misheck; Mathanga, Don P.; Salgado, S. René; Nielsen, Carrie F.; Troell, Peter; Jenda, Gomezgani; Yé, Yazoume; Bhattarai, Achuyt

2017-01-01

Abstract. Malaria control intervention coverage increased nationwide in Malawi during 2000–2010. Trends in intervention coverage were assessed against trends in malaria parasite prevalence, severe anemia (hemoglobin < 8 g/dL), and all-cause mortality in children under 5 years of age (ACCM) using nationally representative household surveys. Associations between insecticide-treated net (ITN) ownership, malaria morbidity, and ACCM were also assessed. Household ITN ownership increased from 27.4% (95% confidence interval [CI] = 25.9–29.0) in 2004 to 56.8% (95% CI = 55.6–58.1) in 2010. Similarly intermittent preventive treatment during pregnancy coverage increased from 28.2% (95% CI = 26.7–29.8) in 2000 to 55.0% (95% CI = 53.4–56.6) in 2010. Malaria parasite prevalence decreased significantly from 60.5% (95% CI = 53.0–68.0) in 2001 to 20.4% (95% CI = 15.7–25.1) in 2009 in children aged 6–35 months. Severe anemia prevalence decreased from 20.4% (95% CI: 17.3–24.0) in 2004 to 13.1% (95% CI = 11.0–15.4) in 2010 in children aged 6–23 months. ACCM decreased 41%, from 188.6 deaths per 1,000 live births (95% CI = 179.1–198.0) during 1996–2000, to 112.1 deaths per 1,000 live births (95% CI = 105.8–118.5) during 2006–2010. When controlling for other covariates in random effects logistic regression models, household ITN ownership was protective against malaria parasitemia in children (odds ratio [OR] = 0.81, 95% CI = 0.72–0.92) and severe anemia (OR = 0.82, 95% CI = 0.72–0.94). After considering the magnitude of changes in malaria intervention coverage and nonmalaria factors, and given the contribution of malaria to all-cause mortality in malaria-endemic countries, the substantial increase in malaria control interventions likely improved child survival in Malawi during 2000–2010. PMID:28990920

Successful malaria elimination in the Ecuador-Peru border region: epidemiology and lessons learned.

PubMed

Krisher, Lyndsay K; Krisher, Jesse; Ambuludi, Mariano; Arichabala, Ana; Beltrán-Ayala, Efrain; Navarrete, Patricia; Ordoñez, Tania; Polhemus, Mark E; Quintana, Fernando; Rochford, Rosemary; Silva, Mercy; Bazo, Juan; Stewart-Ibarra, Anna M

2016-11-28

In recent years, malaria (Plasmodium vivax and Plasmodium falciparum) has been successfully controlled in the Ecuador-Peru coastal border region. The aim of this study was to document this control effort and to identify the best practices and lessons learned that are applicable to malaria control and to other vector-borne diseases. A proximal outcome evaluation was conducted of the robust elimination programme in El Oro Province, Ecuador, and the Tumbes Region, Peru. Data collection efforts included a series of workshops with local public health experts who played central roles in the elimination effort, review of epidemiological records from Ministries of Health, and a review of national policy documents. Key programmatic and external factors are identified that determined the success of this eradication effort. From the mid 1980s until the early 2000s, the region experienced a surge in malaria transmission, which experts attributed to a combination of ineffective anti-malarial treatment, social-ecological factors (e.g., El Niño, increasing rice farming, construction of a reservoir), and political factors (e.g., reduction in resources and changes in management). In response to the malaria crisis, local public health practitioners from El Oro and Tumbes joined together in the mid-1990s to forge an unofficial binational collaboration for malaria control. Over the next 20 years, they effectively eradicated malaria in the region, by strengthening surveillance and treatment strategies, sharing of resources, operational research to inform policy, and novel interventions. The binational collaboration at the operational level was the fundamental component of the successful malaria elimination programme. This unique relationship created a trusting, open environment that allowed for flexibility, rapid response, innovation and resilience in times of crisis, and ultimately a sustainable control programme. Strong community involvement, an extensive microscopy network and ongoing epidemiologic investigations at the local level were also identified as crucial programmatic strategies. The results of this study provide key principles of a successful malaria elimination programme that can inform the next generation of public health professionals in the region, and serve as a guide to ongoing and future control efforts of other emerging vector borne diseases globally.

A micro-epidemiological analysis of febrile malaria in Coastal Kenya showing hotspots within hotspots

PubMed Central

Bejon, Philip; Williams, Thomas N; Nyundo, Christopher; Hay, Simon I; Benz, David; Gething, Peter W; Otiende, Mark; Peshu, Judy; Bashraheil, Mahfudh; Greenhouse, Bryan; Bousema, Teun; Bauni, Evasius; Marsh, Kevin; Smith, David L; Borrmann, Steffen

2014-01-01

Malaria transmission is spatially heterogeneous. This reduces the efficacy of control strategies, but focusing control strategies on clusters or ‘hotspots’ of transmission may be highly effective. Among 1500 homesteads in coastal Kenya we calculated (a) the fraction of febrile children with positive malaria smears per homestead, and (b) the mean age of children with malaria per homestead. These two measures were inversely correlated, indicating that children in homesteads at higher transmission acquire immunity more rapidly. This inverse correlation increased gradually with increasing spatial scale of analysis, and hotspots of febrile malaria were identified at every scale. We found hotspots within hotspots, down to the level of an individual homestead. Febrile malaria hotspots were temporally unstable, but 4 km radius hotspots could be targeted for 1 month following 1 month periods of surveillance. DOI: http://dx.doi.org/10.7554/eLife.02130.001 PMID:24843017

[Malaria and hematological aspects among residents to be impacted by reservoirs for the Santo Antônio and Jirau Hydroelectric Power Stations, Rondônia State, Brazil].

PubMed

Katsuragawa, Tony Hiroshi; Cunha, Roberto Penna de Almeida; de Souza, Daniele Cristina Apoluceno; Gil, Luiz Herman Soares; Cruz, Rafael Bastos; Silva, Alexandre de Almeida E; Tada, Mauro Shugiro; da Silva, Luiz Hildebrando Pereira

2009-07-01

In Rondônia State, Brazil, two new hydroelectric plants, Santo Antônio and Jirau, are scheduled for construction on the Madeira River, upriver from the State capital, Porto Velho. The current study analyzes malaria prevalence before the construction and provides information on the possible impacts of malaria burden related to the influx of thousands of persons attracted by direct and indirect employment opportunities. According to the findings, malaria is present throughout the region, with varying prevalence rates. The existence of potential asymptomatic malaria carriers among the local population may be epidemiologically relevant and should be considered in the malaria control programs organized by public authorities and companies responsible for building the power plants, aimed at early diagnosis and treatment, vector control, water supply, and infrastructure in the urban areas.

Vaccines to Accelerate Malaria Elimination and Eventual Eradication.

PubMed

Healer, Julie; Cowman, Alan F; Kaslow, David C; Birkett, Ashley J

2017-09-01

Remarkable progress has been made in coordinated malaria control efforts with substantial reductions in malaria-associated deaths and morbidity achieved through mass administration of drugs and vector control measures including distribution of long-lasting insecticide-impregnated bednets and indoor residual spraying. However, emerging resistance poses a significant threat to the sustainability of these interventions. In this light, the malaria research community has been charged with the development of a highly efficacious vaccine to complement existing malaria elimination measures. As the past 40 years of investment in this goal attests, this is no small feat. The malaria parasite is a highly complex organism, exquisitely adapted for survival under hostile conditions within human and mosquito hosts. Here we review current vaccine strategies to accelerate elimination and the potential for novel and innovative approaches to vaccine design through a better understanding of the host-parasite interaction. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

A micro-epidemiological analysis of febrile malaria in Coastal Kenya showing hotspots within hotspots.

PubMed

Bejon, Philip; Williams, Thomas N; Nyundo, Christopher; Hay, Simon I; Benz, David; Gething, Peter W; Otiende, Mark; Peshu, Judy; Bashraheil, Mahfudh; Greenhouse, Bryan; Bousema, Teun; Bauni, Evasius; Marsh, Kevin; Smith, David L; Borrmann, Steffen

2014-04-24

Malaria transmission is spatially heterogeneous. This reduces the efficacy of control strategies, but focusing control strategies on clusters or 'hotspots' of transmission may be highly effective. Among 1500 homesteads in coastal Kenya we calculated (a) the fraction of febrile children with positive malaria smears per homestead, and (b) the mean age of children with malaria per homestead. These two measures were inversely correlated, indicating that children in homesteads at higher transmission acquire immunity more rapidly. This inverse correlation increased gradually with increasing spatial scale of analysis, and hotspots of febrile malaria were identified at every scale. We found hotspots within hotspots, down to the level of an individual homestead. Febrile malaria hotspots were temporally unstable, but 4 km radius hotspots could be targeted for 1 month following 1 month periods of surveillance.DOI: http://dx.doi.org/10.7554/eLife.02130.001. Copyright © 2014, Bejon et al.

Persistent foci of falciparum malaria among tribes over two decades in Koraput district of Odisha State, India.

PubMed

Sahu, Sudhansu Sekhar; Gunasekaran, Kasinathan; Vanamail, Perumal; Jambulingam, Purusothaman

2013-02-21

Koraput, a predominantly tribe-inhabited and one of the highly endemic districts of Odisha State that contributes a substantial number of malaria cases to the India's total. Control of malaria in such districts would contribute to change the national scenario on malaria situation. Hence, a study was carried out to measure the magnitude of malaria prevalence in the district to strengthen the malaria control activities. Prevalence of malaria was assessed through a sample blood survey (SBS) in seven randomly selected community health centres (CHCs). Individuals of all age groups in the villages selected (one in each subcentre) were screened for malaria infection. Both thick and thin smears were prepared from blood samples collected by finger prick, stained and examined for malaria parasites searching 100 fields in each smear. The results of a blood survey (n = 10,733) carried out, as a part of another study, during 1986-87 covering a population of 17,722 spread in 37 villages of Koraput district were compared with the current survey results. Software SPSS version 16.0 was used for data analysis. During the current study, blood survey was done in 135 villages screening 12,045 individuals (16.1% of the total population) and among them, 1,983 (16.5%) were found positive for malaria parasites. Plasmodium falciparum was the major malaria parasite species accounted for 89.1% (1,767) of the total positives; Plasmodium vivax and Plasmodium malariae accounted for 9.3% (184) and 0.2% (5), respectively. Gametocytes were found in 7.7% (n = 152) of the positive cases. The majority of parasite carriers (78.9%) were afebrile. The 1986-87 blood survey showed that of 10,733 people screened, 833 (7.8%) were positive for malaria parasites, 714 (85.7%) with P. falciparum, 86 (10.3%) with P. vivax, 12 (1.4%) with P. malariae and 21 (2.5%) with mixed infections. The results of the current study indicated a rising trend in transmission of malaria in Koraput district compared to the situation during 1986-87 and indicated the necessity for a focused and reinforced approach for the control of the disease by improving people's access to diagnosis and treatment and ensuring implementation of the intervention measures with adequate coverage and compliance.

New insight-guided approaches to detect, cure, prevent and eliminate malaria.

PubMed

Kumar, Sushil; Kumari, Renu; Pandey, Richa

2015-05-01

New challenges posed by the development of resistance against artemisinin-based combination therapies (ACTs) as well as previous first-line therapies, and the continuing absence of vaccine, have given impetus to research in all areas of malaria control. This review portrays the ongoing progress in several directions of malaria research. The variants of RTS,S and apical membrane antigen 1 (AMA1) are being developed and test adapted as multicomponent and multistage malaria control vaccines, while many other vaccine candidates and methodologies to produce antigens are under experimentation. To track and prevent the spread of artemisinin resistance from Southeast Asia to other parts of the world, rolling circle-enhanced enzyme activity detection (REEAD), a time- and cost-effective malaria diagnosis in field conditions, and a DNA marker associated with artemisinin resistance have become available. Novel mosquito repellents and mosquito trapping and killing techniques much more effective than the prevalent ones are undergoing field testing. Mosquito lines stably infected with their symbiotic wild-type or genetically engineered bacteria that kill sympatric malaria parasites are being constructed and field tested for stopping malaria transmission. A complementary approach being pursued is the addition of ivermectin-like drug molecules to ACTs to cure malaria and kill mosquitoes. Experiments are in progress to eradicate malaria mosquito by making it genetically male sterile. High-throughput screening procedures are being developed and used to discover molecules that possess long in vivo half life and are active against liver and blood stages for the fast cure of malaria symptoms caused by simple or relapsing and drug-sensitive and drug-resistant types of varied malaria parasites, can stop gametocytogenesis and sporogony and could be given in one dose. Target-based antimalarial drug designing has begun. Some of the putative next-generation antimalarials that possess in their scaffold structure several of the desired properties of malaria cure and control are exemplified by OZ439, NITD609, ELQ300 and tafenoquine that are already undergoing clinical trials, and decoquinate, usnic acid, torin-2, ferroquine, WEHI-916, MMV396749 and benzothiophene-type N-myristoyltransferase (NMT) inhibitors, which are candidates for future clinical usage. Among these, NITD609, ELQ300, decoquinate, usnic acid, torin-2 and NMT inhibitors not only cure simple malaria and are prophylactic against simple malaria, but they also cure relapsing malaria.

Use of prospective hospital surveillance data to define spatiotemporal heterogeneity of malaria risk in coastal Kenya.

PubMed

Bisanzio, Donal; Mutuku, Francis; LaBeaud, Angelle D; Mungai, Peter L; Muinde, Jackson; Busaidy, Hajara; Mukoko, Dunstan; King, Charles H; Kitron, Uriel

2015-12-01

Malaria in coastal Kenya shows spatial heterogeneity and seasonality, which are important factors to account for when planning an effective control system. Routinely collected data at health facilities can be used as a cost-effective method to acquire information on malaria risk for large areas. Here, data collected at one specific hospital in coastal Kenya were used to assess the ability of such passive surveillance to capture spatiotemporal heterogeneity of malaria and effectiveness of an augmented control system. Fever cases were tested for malaria at Msambweni sub-County Referral Hospital, Kwale County, Kenya, from October 2012 to March 2015. Remote sensing data were used to classify the development level of each monitored community and to identify the presence of rice fields nearby. An entomological study was performed to acquire data on the seasonality of malaria vectors in the study area. Rainfall data were obtained from a weather station located in proximity of the study area. Spatial analysis was applied to investigate spatial patterns of malarial and non-malarial fever cases. A space-time Bayesian model was performed to evaluate risk factors and identify locations at high malaria risk. Vector seasonality was analysed using a generalized additive mixed model (GAMM). Among the 25,779 tested febrile cases, 28.7 % were positive for Plasmodium infection. Malarial and non-malarial fever cases showed a marked spatial heterogeneity. High risk of malaria was linked to patient age, community development level and presence of rice fields. The peak of malaria prevalence was recorded close to rainy seasons, which correspond to periods of high vector abundance. Results from the Bayesian model identified areas with significantly high malaria risk. The model also showed that the low prevalence of malaria recorded during late 2012 and early 2013 was associated with a large-scale bed net distribution initiative in the study area during mid-2012. The results indicate that the use of passive surveillance was an effective method to detect spatiotemporal patterns of malaria risk in coastal Kenya. Furthermore, it was possible to estimate the impact of extensive bed net distribution on malaria prevalence among local fever cases over time. Passive surveillance based on georeferenced malaria testing is an important tool that control agencies can use to improve the effectiveness of interventions targeting malaria (and other causes of fever) in such high-risk locations.

Micro-spatial distribution of malaria cases and control strategies at ward level in Gwanda district, Matabeleland South, Zimbabwe.

PubMed

Manyangadze, Tawanda; Chimbari, Moses J; Macherera, Margaret; Mukaratirwa, Samson

2017-11-21

Although there has been a decline in the number of malaria cases in Zimbabwe since 2010, the disease remains the biggest public health threat in the country. Gwanda district, located in Matabeleland South Province of Zimbabwe has progressed to the malaria pre-elimination phase. The aim of this study was to determine the spatial distribution of malaria incidence at ward level for improving the planning and implementation of malaria elimination in the district. The Poisson purely spatial model was used to detect malaria clusters and their properties, including relative risk and significance levels at ward level. The geographically weighted Poisson regression (GWPR) model was used to explore the potential role and significance of environmental variables [rainfall, minimum and maximum temperature, altitude, Enhanced Vegetation Index (EVI), Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), rural/urban] and malaria control strategies [indoor residual spraying (IRS) and long-lasting insecticide-treated nets (LLINs)] on the spatial patterns of malaria incidence at ward level. Two significant clusters (p < 0.05) of malaria cases were identified: (1) ward 24 south of Gwanda district and (2) ward 9 in the urban municipality, with relative risks of 5.583 and 4.316, respectively. The semiparametric-GWPR model with both local and global variables had higher performance based on AICc (70.882) compared to global regression (74.390) and GWPR which assumed that all variables varied locally (73.364). The semiparametric-GWPR captured the spatially non-stationary relationship between malaria cases and minimum temperature, NDVI, NDWI, and altitude at the ward level. The influence of LLINs, IRS and rural or urban did not vary and remained in the model as global terms. NDWI (positive coefficients) and NDVI (range from negative to positive coefficients) showed significant association with malaria cases in some of the wards. The IRS had a protection effect on malaria incidence as expected. Malaria incidence is heterogeneous even in low-transmission zones including those in pre-elimination phase. The relationship between malaria cases and NDWI, NDVI, altitude, and minimum temperature may vary at local level. The results of this study can be used in planning and implementation of malaria control strategies at district and ward levels.

The relative contribution of climate variability and vector control coverage to changes in malaria parasite prevalence in Zambia 2006-2012.

PubMed

Bennett, Adam; Yukich, Josh; Miller, John M; Keating, Joseph; Moonga, Hawela; Hamainza, Busiku; Kamuliwo, Mulakwa; Andrade-Pacheco, Ricardo; Vounatsou, Penelope; Steketee, Richard W; Eisele, Thomas P

2016-08-05

Four malaria indicator surveys (MIS) were conducted in Zambia between 2006 and 2012 to evaluate malaria control scale-up. Nationally, coverage of insecticide-treated nets (ITNs) and indoor residual spraying (IRS) increased over this period, while parasite prevalence in children 1-59 months decreased dramatically between 2006 and 2008, but then increased from 2008 to 2010. We assessed the relative effects of vector control coverage and climate variability on malaria parasite prevalence over this period. Nationally-representative MISs were conducted in April-June of 2006, 2008, 2010 and 2012 to collect household-level information on malaria control interventions such as IRS, ITN ownership and use, and child parasite prevalence by microscopic examination of blood smears. We fitted Bayesian geostatistical models to assess the association between IRS and ITN coverage and climate variability and malaria parasite prevalence. We created predictions of the spatial distribution of malaria prevalence at each time point and compared results of varying IRS, ITN, and climate inputs to assess their relative contributions to changes in prevalence. Nationally, the proportion of households owning an ITN increased from 37.8 % in 2006 to 64.3 % in 2010 and 68.1 % in 2012, with substantial heterogeneity sub-nationally. The population-adjusted predicted child malaria parasite prevalence decreased from 19.6 % in 2006 to 10.4 % in 2008, but rose to 15.3 % in 2010 and 13.5 % in 2012. We estimated that the majority of this prevalence increase at the national level between 2008 and 2010 was due to climate effects on transmission, although there was substantial heterogeneity at the provincial level in the relative contribution of changing climate and ITN availability. We predict that if climate factors preceding the 2010 survey were the same as in 2008, the population-adjusted prevalence would have fallen to 9.9 % nationally. These results suggest that a combination of climate factors and reduced intervention coverage in parts of the country contributed to both the reduction and rebound in malaria parasite prevalence. Unusual rainfall patterns, perhaps related to moderate El Niño conditions, may have contributed to this variation. Zambia has demonstrated considerable success in scaling up vector control. This analysis highlights the importance of accounting for climate variability when using cross-sectional data for evaluation of malaria control efforts.

Urbanization and the global malaria recession

PubMed Central

2013-01-01

Background The past century has seen a significant contraction in the global extent of malaria transmission, resulting in over 50 countries being declared malaria free, and many regions of currently endemic countries eliminating the disease. Moreover, substantial reductions in transmission have been seen since 1900 in those areas that remain endemic today. Recent work showed that this malaria recession was unlikely to have been driven by climatic factors, and that control measures likely played a significant role. It has long been considered, however, that economic development, and particularly urbanization, has also been a causal factor. The urbanization process results in profound socio-economic and landscape changes that reduce malaria transmission, but the magnitude and extent of these effects on global endemicity reductions are poorly understood. Methods Global data at subnational spatial resolution on changes in malaria transmission intensity and urbanization trends over the past century were combined to examine the relationships seen over a range of spatial and temporal scales. Results/Conclusions A consistent pattern of increased urbanization coincident with decreasing malaria transmission and elimination over the past century was found. Whilst it remains challenging to untangle whether this increased urbanization resulted in decreased transmission, or that malaria reductions promoted development, the results point to a close relationship between the two, irrespective of national wealth. The continuing rapid urbanization in malaria-endemic regions suggests that such malaria declines are likely to continue, particularly catalyzed by increasing levels of direct malaria control. PMID:23594701

Malaria overdiagnosis and subsequent overconsumption of antimalarial drugs in Angola: Consequences and effects on human health.

PubMed

Manguin, Sylvie; Foumane, Vincent; Besnard, Patrick; Fortes, Filomeno; Carnevale, Pierre

2017-07-01

Microscopic blood smear examinations done in health centers of Angola demonstrated a large overdiagnosis of malaria cases with an average rate of errors as high as 85%. Overall 83% of patients who received Coartem ® had an inappropriate treatment. Overestimated malaria diagnosis was noticed even when specific symptoms were part of the clinical observation, antimalarial treatments being subsequently given. Then, malaria overdiagnosis has three main consequences, (i) the lack of data reliability is of great concern, impeding epidemiological records and evaluation of the actual influence of operations as scheduled by the National Malaria Control Programme; (ii) the large misuse of antimalarial drug can increase the selective pressure for resistant strain and can make a false consideration of drug resistant P. falciparum crisis; and (iii) the need of strengthening national health centers in term of human, with training in microscopy, and equipment resources to improve malaria diagnosis with a large scale use of rapid diagnostic tests associated with thick blood smears, backed up by a "quality control" developed by the national health authorities. Monitoring of malaria cases was done in three Angolan health centers of Alto Liro (Lobito town) and neighbor villages of Cambambi and Asseque (Benguéla Province) to evaluate the real burden of malaria. Carriers of Plasmodium among patients of newly-borne to 14 years old, with or without fever, were analyzed and compared to presumptive malaria cases diagnosed in these health centers. Presumptive malaria cases were diagnosed six times more than the positive thick blood smears done on the same children. In Alto Liro health center, the percentage of diagnosis error reached 98%, while in Cambambi and Asseque it was of 79% and 78% respectively. The percentage of confirmed malaria cases was significantly higher during the dry (20.2%) than the rainy (13.2%) season. These observations in three peripheral health centers confirmed what has already been noticed in other malaria endemic regions, and highlight the need for an accurate evaluation of the Malaria control programme implemented in Angola. Copyright © 2017 Elsevier B.V. All rights reserved.

Complement receptor 1 variants confer protection from severe malaria in Odisha, India.

PubMed

Panda, Aditya K; Panda, Madhumita; Tripathy, Rina; Pattanaik, Sarit S; Ravindran, Balachandran; Das, Bidyut K

2012-01-01

In Plasmodium falciparum infection, complement receptor-1 (CR1) on erythrocyte's surface and ABO blood group play important roles in formation of rosettes which are presumed to be contributory in the pathogenesis of severe malaria. Although several studies have attempted to determine the association of CR1 polymorphisms with severe malaria, observations remain inconsistent. Therefore, a case control study and meta-analysis was performed to address this issue. Common CR1 polymorphisms (intron 27 and exon 22) and blood group were typed in 353 cases of severe malaria (SM) [97 cerebral malaria (CM), 129 multi-organ dysfunction (MOD), 127 non-cerebral severe malaria (NCSM)], 141 un-complicated malaria and 100 healthy controls from an endemic region of Odisha, India. Relevant publications for meta-analysis were searched from the database. The homozygous polymorphisms of CR1 intron 27 and exon 22 (TT and GG) and alleles (T and G) that are associated with low expression of CR1 on red blood cells, conferred significant protection against CM, MOD and malaria deaths. Combined analysis showed significant association of blood group B/intron 27-AA/exon 22-AA with susceptibility to SM (CM and MOD). Meta-analysis revealed that the CR1 exon 22 low expression polymorphism is significantly associated with protection against severe malaria. The results of the present study demonstrate that common CR1 variants significantly protect against severe malaria in an endemic area.

The Gates Malaria Partnership: a consortium approach to malaria research and capacity development.

PubMed

Greenwood, Brian; Bhasin, Amit; Targett, Geoffrey

2012-05-01

Recently, there has been a major increase in financial support for malaria control. Most of these funds have, appropriately, been spent on the tools needed for effective prevention and treatment of malaria such as insecticide-treated bed nets, indoor residual spraying and artemisinin combination therapy. There has been less investment in the training of the scientists from malaria-endemic countries needed to support these large and increasingly complex malaria control programmes, especially in Africa. In 2000, with support from the Bill & Melinda Gates Foundation, the Gates Malaria Partnership was established to support postgraduate training of African scientists wishing to pursue a career in malaria research. The programme had three research capacity development components: a PhD fellowship programme, a postdoctoral fellowship programme and a laboratory infrastructure programme. During an 8-year period, 36 African PhD students and six postdoctoral fellows were supported, and two research laboratories were built in Tanzania. Some of the lessons learnt during this project--such as the need to improve PhD supervision in African universities and to provide better support for postdoctoral fellows--are now being applied to a successor malaria research capacity development programme, the Malaria Capacity Development Consortium, and may be of interest to other groups involved in improving postgraduate training in health sciences in African universities. © 2012 Blackwell Publishing Ltd.

78 FR 20319 - Disease, Disability, and Injury Prevention and Control Special Emphasis Panel (SEP): Initial Review

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-04

... GH13-004; Monitoring and Evaluation of Malaria Control and Elimination Activities, FOA GH13-005; and...; Monitoring and Evaluation of Malaria Control and Elimination Activities, FOA GH13-005; and Research and...

School-based participatory health education for malaria control in Ghana: engaging children as health messengers.

PubMed

Ayi, Irene; Nonaka, Daisuke; Adjovu, Josiah K; Hanafusa, Shigeki; Jimba, Masamine; Bosompem, Kwabena M; Mizoue, Tetsuya; Takeuchi, Tsutomu; Boakye, Daniel A; Kobayashi, Jun

2010-04-18

School children have been increasingly recognized as health messengers for malaria control. However, little evidence is available. The objective of this study was to determine the impact of school-based malaria education intervention on school children and community adults. This study was conducted in the Dangme-East district of the Greater Accra Region, Ghana, between 2007 and 2008. Trained schoolteachers designed participatory health education activities and led school children to disseminate messages related to malaria control to their communities. Three schools and their respective communities were chosen for the study and assigned to an intervention group (one school) and a control group (two schools). Questionnaire-based interviews and parasitological surveys were conducted before and after the intervention, with the intervention group (105 children, 250 community adults) and the control group (81 children, 133 community adults). Chi-square and Fisher's Exact tests were used to analyse differences in knowledge, practices, and parasite prevalence between pre- and post-intervention. After the intervention, the misperception that malaria has multiple causes was significantly improved, both among children and community adults. Moreover, the community adults who treated a bed net with insecticide in the past six months, increased from 21.5% to 50.0% (p < 0.001). Parasite prevalence in school children decreased from 30.9% to 10.3% (p = 0.003). These positive changes were observed only in the intervention group. This study suggests that the participatory health education intervention contributed to the decreased malaria prevalence among children. It had a positive impact not only on school children, but also on community adults, through the improvement of knowledge and practices. This strategy can be applied as a complementary approach to existing malaria control strategies in West African countries where school health management systems have been strengthened.

Efficacy of intermittent preventive treatment of malaria with sulphadoxine-pyrimethamine in preventing anaemia in pregnancy among Nigerian women.

PubMed

Asa, O O; Onayade, A A; Fatusi, A O; Ijadunola, K T; Abiona, T C

2008-11-01

To evaluate the efficacy of intermittent preventive treatment of malaria using sulphadoxine-pyrimethamine (SP) in the prevention of anaemia in women of low parity in a low socio-economic, malaria endemic setting. The study design was an open randomized control trial comparing anaemia incidence among pregnant women on intermittent presumptive treatment of malaria with SP with those on chloroquine (CQ). A total of 352 primigravid and secondigravid women between 16 and 30 weeks gestation receiving antenatal care at the Primary Health Care Center, Enuwa in Ile-Ife, Osun State, Nigeria were serially recruited and randomly allocated into experimental and control groups of 176 each. The experimental group received SP (to a maximum of three doses depending on the gestational age at enrollment into the study) while the control group had treatment doses of CQ at recruitment and subsequently only if they had symptoms suggestive of malaria. The primary outcome measure was anaemia (haematocrit<30) at 34 weeks of gestation. At recruitment and 34 weeks gestation, there was no statistically significant difference between the experimental and control group in terms of socio-demographic characteristics and past medical history. Thirty-three (22.6%) and 52 (37.1%) women in the study and control groups, respectively, had anaemia (protective efficacy 49.5%, p=0.01). With multivariate analysis, controlling for the possible confounding effects of education, parity, haemoglobin level at booking and malaria parasitaemia in peripheral blood, the difference in the incidence of anaemia in the two groups remained significant (p=0.01; odds ratio=0.5; 95% confidence interval=0.29-0.85). The IPT regime with sulphadoxine-pyrimethamine is an effective, practicable strategy to decrease risk of anaemia in women of low parity residing in areas endemic for malaria.

A Field Trial to Assess a Blood-Stage Malaria Vaccine

PubMed Central

Thera, Mahamadou A.; Doumbo, Ogobara K.; Coulibaly, Drissa; Laurens, Matthew B.; Ouattara, Amed; Kone, Abdoulaye K.; Guindo, Ando B.; Traore, Karim; Traore, Idrissa; Kouriba, Bourema; Diallo, Dapa A.; Diarra, Issa; Daou, Modibo; Dolo, Amagana; Tolo, Youssouf; Sissoko, Mahamadou S.; Niangaly, Amadou; Sissoko, Mady; Takala-Harrison, Shannon; Lyke, Kirsten E.; Wu, Yukun; Blackwelder, William C.; Godeaux, Olivier; Vekemans, Johan; Dubois, Marie-Claude; Ballou, W. Ripley; Cohen, Joe; Thompson, Darby; Dube, Tina; Soisson, Lorraine; Diggs, Carter L.; House, Brent; Lanar, David E.; Dutta, Sheetij; Heppner, D. Gray; Plowe, Christopher V.

2011-01-01

BACKGROUND Blood-stage malaria vaccines are intended to prevent clinical disease. The malaria vaccine FMP2.1/AS02A, a recombinant protein based on apical membrane antigen 1 (AMA1) from the 3D7 strain of Plasmodium falciparum, has previously been shown to have immunogenicity and acceptable safety in Malian adults and children. METHODS In a double-blind, randomized trial, we immunized 400 Malian children with either the malaria vaccine or a control (rabies) vaccine and followed them for 6 months. The primary end point was clinical malaria, defined as fever and at least 2500 parasites per cubic millimeter of blood. A secondary end point was clinical malaria caused by parasites with the AMA1 DNA sequence found in the vaccine strain. RESULTS The cumulative incidence of the primary end point was 48.4% in the malaria-vaccine group and 54.4% in the control group; efficacy against the primary end point was 17.4% (hazard ratio for the primary end point, 0.83; 95% confidence interval [CI], 0.63 to 1.09; P = 0.18). Efficacy against the first and subsequent episodes of clinical malaria, as defined on the basis of various parasite-density thresholds, was approximately 20%. Efficacy against clinical malaria caused by parasites with AMA1 corresponding to that of the vaccine strain was 64.3% (hazard ratio, 0.36; 95% CI, 0.08 to 0.86; P = 0.03). Local reactions and fever after vaccination were more frequent with the malaria vaccine. CONCLUSIONS On the basis of the primary end point, the malaria vaccine did not provide significant protection against clinical malaria, but on the basis of secondary results, it may have strain-specific efficacy. If this finding is confirmed, AMA1 might be useful in a multicomponent malaria vaccine. PMID:21916638

Short report: entomologic inoculation rates and Plasmodium falciparum malaria prevalence in Africa.

PubMed

Beier, J C; Killeen, G F; Githure, J I

1999-07-01

Epidemiologic patterns of malaria infection are governed by environmental parameters that regulate vector populations of Anopheles mosquitoes. The intensity of malaria parasite transmission is normally expressed as the entomologic inoculation rate (EIR), the product of the vector biting rate times the proportion of mosquitoes infected with sporozoite-stage malaria parasites. Malaria transmission intensity in Africa is highly variable with annual EIRs ranging from < 1 to > 1,000 infective bites per person per year. Malaria control programs often seek to reduce morbidity and mortality due to malaria by reducing or eliminating malaria parasite transmission by mosquitoes. This report evaluates data from 31 sites throughout Africa to establish fundamental relationships between annual EIRs and the prevalence of Plasmodium falciparum malaria infection. The majority of sites fitted a linear relationship (r2 = 0.71) between malaria prevalence and the logarithm of the annual EIR. Some sites with EIRs < 5 infective bites per year had levels of P. falciparum prevalence exceeding 40%. When transmission exceeded 15 infective bites per year, there were no sites with prevalence rates < 50%. Annual EIRs of 200 or greater were consistently associated with prevalence rates > 80%. The basic relationship between EIR and P. falciparum prevalence, which likely holds in east and west Africa, and across different ecologic zones, shows convincingly that substantial reductions in malaria prevalence are likely to be achieved only when EIRs are reduced to levels less than 1 infective bite per person per year. The analysis also highlights that the EIR is a more direct measure of transmission intensity than traditional measures of malaria prevalence or hospital-based measures of infection or disease incidence. As such, malaria field programs need to consider both entomologic and clinical assessments of the efficacy of transmission control measures.

Acquired immunity against malaria as a tool for the control of the disease: the strategy proposed by the Malaria Commission of the League of Nations in 1933.

PubMed

Corbellini, G

1998-06-01

The Third General Report of the Malaria Commission, printed in 1933, suggested for the control of malaria a strategy aimed to promote the acquisition of a "relative immunity" through a non radical treatment of the infected people living in highly endemic areas. The paper discusses the content of the Report and describes the scientific (empirical) premises on which it stood. Moreover, it illustrates the criticism that was directed against the immunological strategy and that eventually led to its abandonment.

The Changing Limits and Incidence of Malaria in Africa: 1939–2009

PubMed Central

Snow, Robert W.; Amratia, Punam; Kabaria, Caroline W.; Noor, Abdisalan M.; Marsh, Kevin

2012-01-01

Understanding the historical, temporal changes of malaria risk following control efforts in Africa provides a unique insight into what has been and might be archived towards a long-term ambition of elimination on the continent. Here, we use archived published and unpublished material combined with biological constraints on transmission accompanied by a narrative on malaria control to document the changing incidence of malaria in Africa since earliest reports pre-second World War. One result is a more informed mapped definition of the changing margins of transmission in 1939, 1959, 1979, 1999 and 2009. PMID:22520443

Malaria in South Asia: Prevalence and control

PubMed Central

Kumar, Ashwani; Chery, Laura; Biswas, Chinmoy; Dubhashi, Nagesh; Dutta, Prafulla; Dua, Virendra Kumar; Kacchap, Mridula; Kakati, Sanjeeb; Khandeparkar, Anar; Kour, Dalip; Mahajanj, Satish N.; Maji, Ardhendu; Majumder, Partha; Mohanta, Jagadish; Mohapatra, Pradyumna K.; Narayanasamy, Krishnamoorthy; Roy, Krishnangshu; Shastri, Jayanthi; Valecha, Neena; Vikash, Rana; Wani, Reena; White, John; Rathod, Pradipsinh K

2013-01-01

The “Malaria Evolution in South Asia” (MESA) program project is an International Center of Excellence for Malaria Research (ICEMR) sponsored by the US National Institutes of Health. This US–India collaborative program will study the origin of genetic diversity of malaria parasites and their selection on the Indian subcontinent. This knowledge should contribute to a better understanding of unexpected disease outbreaks and unpredictable disease presentations from Plasmodium falciparum and Plasmodium vivax infections. In this first of two reviews, we highlight malaria prevalence in India. In particular, we draw attention to variations in distribution of different human-parasites and different vectors, variation in drug resistance traits, and multiple forms of clinical presentations. Uneven malaria severity in India is often attributed to large discrepancies in health care accessibility as well as human migrations within the country and across neighboring borders. Poor access to health care goes hand in hand with poor reporting from some of the same areas, combining to possibly distort disease prevalence and death from malaria in some parts of India. Corrections are underway in the form of increased resources for disease control, greater engagement of village-level health workers for early diagnosis and treatment, and possibly new public–private partnerships activities accompanying traditional national malaria control programs in the most severely affected areas. A second accompanying review raises the possibility that, beyond uneven health care, evolutionary pressures may alter malaria parasites in ways that contribute to severe disease in India, particularly in the NE corridor of India bordering Myanmar Narayanasamy et al., 2012. PMID:22248528

Malaria in South Asia: prevalence and control.

PubMed

Kumar, Ashwani; Chery, Laura; Biswas, Chinmoy; Dubhashi, Nagesh; Dutta, Prafulla; Dua, Virendra Kumar; Kacchap, Mridula; Kakati, Sanjeeb; Khandeparkar, Anar; Kour, Dalip; Mahajan, Satish N; Maji, Ardhendu; Majumder, Partha; Mohanta, Jagadish; Mohapatra, Pradyumna K; Narayanasamy, Krishnamoorthy; Roy, Krishnangshu; Shastri, Jayanthi; Valecha, Neena; Vikash, Rana; Wani, Reena; White, John; Rathod, Pradipsinh K

2012-03-01

The "Malaria Evolution in South Asia" (MESA) program project is an International Center of Excellence for Malaria Research (ICEMR) sponsored by the US National Institutes of Health. This US-India collaborative program will study the origin of genetic diversity of malaria parasites and their selection on the Indian subcontinent. This knowledge should contribute to a better understanding of unexpected disease outbreaks and unpredictable disease presentations from Plasmodium falciparum and Plasmodium vivax infections. In this first of two reviews, we highlight malaria prevalence in India. In particular, we draw attention to variations in distribution of different human-parasites and different vectors, variation in drug resistance traits, and multiple forms of clinical presentations. Uneven malaria severity in India is often attributed to large discrepancies in health care accessibility as well as human migrations within the country and across neighboring borders. Poor access to health care goes hand in hand with poor reporting from some of the same areas, combining to possibly distort disease prevalence and death from malaria in some parts of India. Corrections are underway in the form of increased resources for disease control, greater engagement of village-level health workers for early diagnosis and treatment, and possibly new public-private partnerships activities accompanying traditional national malaria control programs in the most severely affected areas. A second accompanying review raises the possibility that, beyond uneven health care, evolutionary pressures may alter malaria parasites in ways that contribute to severe disease in India, particularly in the NE corridor of India bordering Myanmar Narayanasamy et al., 2012. Copyright © 2012 Elsevier B.V. All rights reserved.

Falciparum Malaria Outbreak in Sabah Linked to an Immigrant Rubber Tapper.

PubMed

Jeffree, Saffree Mohammad; Ahmed, Kamruddin; Safian, Nazarudin; Hassan, Rohaizat; Mihat, Omar; Lukman, Khamisah Awang; Shamsudin, Shamsul Bahari; Kamaludin, Fadzilah

2018-01-01

Sabah is a Malaysian state situated in the northern part of Borneo, and it is endemic for malaria. The incidence of malaria is the lowest (0.05/1,000 population) in Penampang districts of Sabah. In June 26, 2012, two Plasmodium falciparum malaria cases were notified to public health department from a village in Penampang. Immediate investigation was initiated to identify the risk factors and to institute control measures. We performed active case finding by asking household members of all houses in the village regarding malaria symptoms and by examining blood smears. Environmental investigation was performed by collecting samples to detect mosquito breeding sites and to identify malaria transmitting vector mosquitoes. A case-control study with a ratio of 1:4 (11 cases and 44 controls) was conducted using self-administered questionnaire. The microscopic examination of blood smear for malarial parasite and entomology sampling was carried out. The malarial attack rate was 2.3%, 6/11 smears have gametocyte, and the case fatality rate was 9.1%. One case was a migrant rubber tapper from Indonesia which happened to be the first case with gametocyte positive. Overall, the incidence of malaria was higher (6/11) among rubber tappers. The odds of cases for those living nearby stagnant water were 7.3 [95% confidence interval: 1.2-43.5] times higher. In conclusion, an outbreak of P. falciparum malaria was introduced into a malaria-free village by a migrant rubber tapper, by whom the imported parasite was introduced to the community via vector Anopheles balabacensis . Living near stagnant water bodies was the risk factor in this outbreak.

To assess whether indoor residual spraying can provide additional protection against clinical malaria over current best practice of long-lasting insecticidal mosquito nets in The Gambia: study protocol for a two-armed cluster-randomised trial

PubMed Central

2011-01-01

Background Recently, there has been mounting interest in scaling-up vector control against malaria in Africa. It needs to be determined if indoor residual spraying (IRS with DDT) will provide significant marginal protection against malaria over current best practice of long-lasting insecticidal nets (LLINs) and prompt treatment in a controlled trial, given that DDT is currently the most persistent insecticide for IRS. Methods A 2 armed cluster-randomised controlled trial will be conducted to assess whether DDT IRS and LLINs combined provide better protection against clinical malaria in children than LLINs alone in rural Gambia. Each cluster will be a village, or a group of small adjacent villages; all clusters will receive LLINs and half will receive IRS in addition. Study children, aged 6 months to 13 years, will be enrolled from all clusters and followed for clinical malaria using passive case detection to estimate malaria incidence for 2 malaria transmission seasons in 2010 and 2011. This will be the primary endpoint. Exposure to malaria parasites will be assessed using light and exit traps followed by detection of Anopheles gambiae species and sporozoite infection. Study children will be surveyed at the end of each transmission season to estimate the prevalence of Plasmodium falciparum infection and the prevalence of anaemia. Discussion Practical issues concerning intervention implementation, as well as the potential benefits and risks of the study, are discussed. Trial Registration ISRCTN01738840 - Spraying And Nets Towards malaria Elimination (SANTE) PMID:21663656

Association between recent internal travel and malaria in Ugandan highland and highland fringe areas.

PubMed

Lynch, Caroline A; Bruce, Jane; Bhasin, Amit; Roper, Cally; Cox, Jonathan; Abeku, Tarekegn A

2015-06-01

To examine the association between travel (recency of travel, transmission intensity at destination compared to origin and duration of travel) and confirmed malaria in Uganda. Health facility-based case-control study in highland (~2200 m), and highland fringe (~1500 m) areas with adjustment for other covariates. In the highland site, patients who had travelled to areas of higher transmission intensity than their home (origin) areas recently were nearly seven times more likely to have confirmed malaria than those who had not (OR 6.9; P = 0.01, 95% CI: 1.4-33.1). In the highland fringe site, there was also a statistically significant association between travel and malaria (OR 2.1; P = 0.04, 95% CI: 1.1-3.9). For highland areas, or areas of low malaria transmission, health authorities need to consider internal migrants when designing malaria control programs. Control interventions should include information campaigns reminding residents in these areas of the risk of malaria infection through travel and to provide additional mosquito nets for migrants to use during travel. Health authorities may wish to improve diagnosis in health facilities in highland areas by adding travel history to malaria case definitions. Where routine monitoring data are used to evaluate the impact of interventions on the malaria burden in highland areas, health authorities and donors need ensure that only cases from the local area and not 'imported cases' are counted. © 2015 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.

Vaccines Against Malaria

PubMed Central

Ouattara, Amed; Laurens, Matthew B.

2015-01-01

Despite global efforts to control malaria, the illness remains a significant public health threat. Currently, there is no licensed vaccine against malaria, but an efficacious vaccine would represent an important public health tool for successful malaria elimination. Malaria vaccine development continues to be hindered by a poor understanding of antimalarial immunity, a lack of an immune correlate of protection, and the genetic diversity of malaria parasites. Current vaccine development efforts largely target Plasmodium falciparum parasites in the pre-erythrocytic and erythrocytic stages, with some research on transmission-blocking vaccines against asexual stages and vaccines against pregnancy-associated malaria. The leading pre-erythrocytic vaccine candidate is RTS,S, and early results of ongoing Phase 3 testing show overall efficacy of 46% against clinical malaria. The next steps for malaria vaccine development will focus on the design of a product that is efficacious against the highly diverse strains of malaria and the identification of a correlate of protection against disease. PMID:25452593

The Value of Information in Decision-Analytic Modeling for Malaria Vector Control in East Africa.

PubMed

Kim, Dohyeong; Brown, Zachary; Anderson, Richard; Mutero, Clifford; Miranda, Marie Lynn; Wiener, Jonathan; Kramer, Randall

2017-02-01

Decision analysis tools and mathematical modeling are increasingly emphasized in malaria control programs worldwide to improve resource allocation and address ongoing challenges with sustainability. However, such tools require substantial scientific evidence, which is costly to acquire. The value of information (VOI) has been proposed as a metric for gauging the value of reduced model uncertainty. We apply this concept to an evidenced-based Malaria Decision Analysis Support Tool (MDAST) designed for application in East Africa. In developing MDAST, substantial gaps in the scientific evidence base were identified regarding insecticide resistance in malaria vector control and the effectiveness of alternative mosquito control approaches, including larviciding. We identify four entomological parameters in the model (two for insecticide resistance and two for larviciding) that involve high levels of uncertainty and to which outputs in MDAST are sensitive. We estimate and compare a VOI for combinations of these parameters in evaluating three policy alternatives relative to a status quo policy. We find having perfect information on the uncertain parameters could improve program net benefits by up to 5-21%, with the highest VOI associated with jointly eliminating uncertainty about reproductive speed of malaria-transmitting mosquitoes and initial efficacy of larviciding at reducing the emergence of new adult mosquitoes. Future research on parameter uncertainty in decision analysis of malaria control policy should investigate the VOI with respect to other aspects of malaria transmission (such as antimalarial resistance), the costs of reducing uncertainty in these parameters, and the extent to which imperfect information about these parameters can improve payoffs. © 2016 Society for Risk Analysis.