Clinical malaria case definition and malaria attributable fraction in the highlands of western Kenya.

PubMed

Afrane, Yaw A; Zhou, Guofa; Githeko, Andrew K; Yan, Guiyun

2014-10-15

In African highland areas where endemicity of malaria varies greatly according to altitude and topography, parasitaemia accompanied by fever may not be sufficient to define an episode of clinical malaria in endemic areas. To evaluate the effectiveness of malaria interventions, age-specific case definitions of clinical malaria needs to be determined. Cases of clinical malaria through active case surveillance were quantified in a highland area in Kenya and defined clinical malaria for different age groups. A cohort of over 1,800 participants from all age groups was selected randomly from over 350 houses in 10 villages stratified by topography and followed for two-and-a-half years. Participants were visited every two weeks and screened for clinical malaria, defined as an individual with malaria-related symptoms (fever [axillary temperature≥37.5°C], chills, severe malaise, headache or vomiting) at the time of examination or 1-2 days prior to the examination in the presence of a Plasmodium falciparum positive blood smear. Individuals in the same cohort were screened for asymptomatic malaria infection during the low and high malaria transmission seasons. Parasite densities and temperature were used to define clinical malaria by age in the population. The proportion of fevers attributable to malaria was calculated using logistic regression models. Incidence of clinical malaria was highest in valley bottom population (5.0% cases per 1,000 population per year) compared to mid-hill (2.2% cases per 1,000 population per year) and up-hill (1.1% cases per 1,000 population per year) populations. The optimum cut-off parasite densities through the determination of the sensitivity and specificity showed that in children less than five years of age, 500 parasites per μl of blood could be used to define the malaria attributable fever cases for this age group. In children between the ages of 5-14, a parasite density of 1,000 parasites per μl of blood could be used to define the

Community perceptions of malaria and vaccines in the South Coast and Busia regions of Kenya.

PubMed

Ojakaa, David I; Ofware, Peter; Machira, Yvonne W; Yamo, Emmanuel; Collymore, Yvette; Ba-Nguz, Antoinette; Vansadia, Preeti; Bingham, Allison

2011-05-30

Malaria is a leading cause of morbidity and mortality in children younger than 5 years in Kenya. Within the context of planning for a vaccine to be used alongside existing malaria control methods, this study explores sociocultural and health communications issues among individuals who are responsible for or influence decisions on childhood vaccination at the community level. This qualitative study was conducted in two malaria-endemic regions of Kenya--South Coast and Busia. Participant selection was purposive and criterion based. A total of 20 focus group discussions, 22 in-depth interviews, and 18 exit interviews were conducted. Participants understand that malaria is a serious problem that no single tool can defeat. Communities would welcome a malaria vaccine, although they would have questions and concerns about the intervention. While support for local child immunization programs exists, limited understanding about vaccines and what they do is evident among younger and older people, particularly men. Even as health care providers are frustrated when parents do not have their children vaccinated, some parents have concerns about access to and the quality of vaccination services. Some women, including older mothers and those less economically privileged, see themselves as the focus of health workers' negative comments associated with either their parenting choices or their children's appearance. In general, parents and caregivers weigh several factors--such as personal opportunity costs, resource constraints, and perceived benefits--when deciding whether or not to have their children vaccinated, and the decision often is influenced by a network of people, including community leaders and health workers. The study raises issues that should inform a communications strategy and guide policy decisions within Kenya on eventual malaria vaccine introduction. Unlike the current practice, where health education on child welfare and immunization focuses on women, the

Local illness concepts and their relevance for the prevention and control of malaria during pregnancy in Ghana, Kenya and Malawi: findings from a comparative qualitative study.

PubMed

Menaca, Arantza; Pell, Christopher; Manda-Taylor, Lucinda; Chatio, Samuel; Afrah, Nana A; Were, Florence; Hodgson, Abraham; Ouma, Peter; Kalilani, Linda; Tagbor, Harry; Pool, Robert

2013-07-22

In sub-Saharan Africa, the burden of morbidity and mortality linked to malaria during pregnancy (MiP) is significant and compounded by its unclear symptoms and links with other health problems during pregnancy. Mindful of the biomedical and social complexity of MiP, this article explores and compares local understandings of MiP and their links with other pregnancy-related health problems. A comparative qualitative study was undertaken at four sites in three countries: Ghana, Malawi and Kenya. Individual and group interviews were conducted with pregnant women, their relatives, opinion leaders, other community members and health providers. MiP-related behaviours were also observed at health facilities and in local communities. Across the four sites, local malaria concepts overlapped with biomedically defined malaria. In terms of symptoms, at-risk groups, outcomes and aetiology of malaria during pregnancy, this overlap was however both site-specific and partial. Moreover, the local malaria concepts were not monolithic and their descriptions varied amongst respondents. The symptoms of pregnancy and malaria also overlapped but, for respondents, symptom severity was the distinguishing factor. Malaria was generally, though not universally, perceived as serious for pregnant women. Miscarriage was the most widely known outcome, and links with anaemia, low birth weight and congenital malaria were mentioned. Nonetheless, amongst many potential causes of miscarriage, malaria was not recognized as the most important, but rather interacted with other pregnancy-related problems. Given the overlap of common pregnancy problems with the symptoms of malaria, and the limited association of malaria with its main outcomes, a comprehensive antenatal care programme is the most appropriate strategy for the provision of health education, prevention and treatment for MiP. Variations in locally shared understandings of MiP must however be taken into account when designing and promoting Mi

Local illness concepts and their relevance for the prevention and control of malaria during pregnancy in Ghana, Kenya and Malawi: findings from a comparative qualitative study

PubMed Central

2013-01-01

Background In sub-Saharan Africa, the burden of morbidity and mortality linked to malaria during pregnancy (MiP) is significant and compounded by its unclear symptoms and links with other health problems during pregnancy. Mindful of the biomedical and social complexity of MiP, this article explores and compares local understandings of MiP and their links with other pregnancy-related health problems. Methods A comparative qualitative study was undertaken at four sites in three countries: Ghana, Malawi and Kenya. Individual and group interviews were conducted with pregnant women, their relatives, opinion leaders, other community members and health providers. MiP-related behaviours were also observed at health facilities and in local communities. Results Across the four sites, local malaria concepts overlapped with biomedically defined malaria. In terms of symptoms, at-risk groups, outcomes and aetiology of malaria during pregnancy, this overlap was however both site-specific and partial. Moreover, the local malaria concepts were not monolithic and their descriptions varied amongst respondents. The symptoms of pregnancy and malaria also overlapped but, for respondents, symptom severity was the distinguishing factor. Malaria was generally, though not universally, perceived as serious for pregnant women. Miscarriage was the most widely known outcome, and links with anaemia, low birth weight and congenital malaria were mentioned. Nonetheless, amongst many potential causes of miscarriage, malaria was not recognized as the most important, but rather interacted with other pregnancy-related problems. Conclusions Given the overlap of common pregnancy problems with the symptoms of malaria, and the limited association of malaria with its main outcomes, a comprehensive antenatal care programme is the most appropriate strategy for the provision of health education, prevention and treatment for MiP. Variations in locally shared understandings of MiP must however be taken into

Surveillance of malaria vector population density and biting behaviour in western Kenya.

PubMed

Ototo, Ednah N; Mbugi, Jenard P; Wanjala, Christine L; Zhou, Guofa; Githeko, Andrew K; Yan, Guiyun

2015-06-17

Malaria is a great public health burden and Africa suffers the largest share of malaria-attributed deaths. Despite control efforts targeting indoor malaria transmission, such as insecticide-treated bed nets (ITNs) and deployment of indoor residual spraying, transmission of the parasite in western Kenya is still maintained. This study was carried out to determine the impact of ITNs on indoor vector densities and biting behaviour in western Kenya. Indoor collection of adult mosquitoes was done monthly in six study sites in western Kenya using pyrethrum spray collections from 2012 to 2014. The rotator trap collections were done in July-August in 2013 and May-June in 2014. Mosquitoes were collected every 2 h between 18.00 and 08.00 h. Human behaviour study was conducted via questionnaire surveys. Species within Anopheles gambiae complex was differentiated by PCR and sporozoite infectivity was determined by ELISA. Species distribution was determined and bed net coverage in the study sites was recorded. During the study a total of 5,469 mosquito vectors were collected from both PSC and Rotator traps comprising 3,181 (58.2%) Anopheles gambiae and 2,288 (41.8%) Anopheles funestus. Compared to all the study sites, Rae had the highest density of An. gambiae with a mean of 1.2 (P<0.001) while Kombewa had the highest density of An. funestus with a mean of 1.08 (P<0.001). Marani had the lowest density of vectors with 0.06 An. gambiae and 0.17 An. funestus (P<0.001). Among the 700 PCR confirmed An. gambiae s.l. individuals, An. gambiae s.s. accounted for 49% and An. arabiensis 51%. Over 50% of the study population stayed outdoors between 18.00 and 20.00 and 06.00 and 08.00 which was the time when highest densities of blood fed vectors were collected. Anopheles gambie s.s. was the main malaria parasite vector in the highland sites and An. arabiensis in the lowland sites. Bed net ownership in 2012 averaged 87% across the study sites. This study suggests that mass distribution of

Effect of haematinic supplementation and malaria prevention on maternal anaemia and malaria in western Kenya.

PubMed

van Eijk, Anna M; Ayisi, John G; Slutsker, Laurence; Ter Kuile, Feiko O; Rosen, Daniel H; Otieno, Juliana A; Shi, Ya-Ping; Kager, Piet A; Steketee, Richard W; Nahlen, Bernard L

2007-03-01

To evaluate the effect of routine antenatal haematinic supplementation programmes and intermittent preventive treatment (IPT) with sulphadoxine-pyrimethamine (SP) in Kenya. Anaemia [haemoglobin (Hb) <11 g/dl), severe anaemia (Hb <8 g/dl) and placental malaria were compared among women with known HIV status who delivered at a provincial hospital after study enrolment in the third trimester during three consecutive periods: period 1, no routine intervention (reference); period 2, routine haematinic supplementation (60 mg elementary iron three times/day, folic acid 5 mg once daily) and period 3, haematinics and IPT with SP. Among 3108 participants, prevalence of placental malaria, anaemia and severe anaemia postpartum was 16.7%, 53.6% and 12.7%, respectively. Compared with period 1, women in period 2 were less anaemic [adjusted odds ratio (AOR), 95% confidence interval anaemia: 0.56, 0.47-0.67; severe anaemia 0.37, 0.28-0.49] and shared a similar prevalence of placental malaria (AOR 1.07, 0.86-1.32). Women in period 3 were also less anaemic (AOR anaemia: 0.43, 0.35-0.53 and severe anaemia: 0.43, 0.31-0.59), and had less placental malaria (AOR 0.56, 0.42-0.73). The effect of intervention did not differ significantly by HIV status. The haematinic supplementation programme was associated with significant reductions in anaemia in HIV-seropositive and HIV-seronegative women. The subsequent introduction of IPT was associated with halving of malaria, but no additional haematological benefit over haematinics.

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

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.

Community perceptions of malaria and vaccines in the South Coast and Busia regions of Kenya

PubMed Central

2011-01-01

Background Malaria is a leading cause of morbidity and mortality in children younger than 5 years in Kenya. Within the context of planning for a vaccine to be used alongside existing malaria control methods, this study explores sociocultural and health communications issues among individuals who are responsible for or influence decisions on childhood vaccination at the community level. Methods This qualitative study was conducted in two malaria-endemic regions of Kenya--South Coast and Busia. Participant selection was purposive and criterion based. A total of 20 focus group discussions, 22 in-depth interviews, and 18 exit interviews were conducted. Results Participants understand that malaria is a serious problem that no single tool can defeat. Communities would welcome a malaria vaccine, although they would have questions and concerns about the intervention. While support for local child immunization programs exists, limited understanding about vaccines and what they do is evident among younger and older people, particularly men. Even as health care providers are frustrated when parents do not have their children vaccinated, some parents have concerns about access to and the quality of vaccination services. Some women, including older mothers and those less economically privileged, see themselves as the focus of health workers' negative comments associated with either their parenting choices or their children's appearance. In general, parents and caregivers weigh several factors--such as personal opportunity costs, resource constraints, and perceived benefits--when deciding whether or not to have their children vaccinated, and the decision often is influenced by a network of people, including community leaders and health workers. Conclusions The study raises issues that should inform a communications strategy and guide policy decisions within Kenya on eventual malaria vaccine introduction. Unlike the current practice, where health education on child welfare and

Chloroquine-resistant falciparum malaria in Madagascar and Kenya.

PubMed

Aronsson, B; Bengtsson, E; Björkman, A; Pehrson, P O; Rombo, L; Wahlgren, M

1981-08-01

3 African cases of chloroquine-resistent (RI) P. falciparum malaria, proved by recrudescences after administration of recommended doses and adequate serum levels of chloroquine, are described. The 3 patients, Swedish women aged 43, 27, and 41, had never visited areas where chloroquine-resistent P. falciparum is known to exist. 2 patients had taken regular prophylaxis with chloroquine, while the 3rd had interrupted chloroquine use with temporary use of pyrimethamine. All 3 were treated with chloroquine and had serum levels well above those considered necessary for cure of malaria due to sensitive strains of P. falciparum. All had recrudescences, ranging from 13 to 41 days after the previous chloroquine treatment. Reinfection was not possible for any of the patients and none took other drugs during the study period. In 2 cases the Rieckmann in vitro test for resistence failed. In 1 case from Madagascar the in vitro method described by Nguyen-Dinh and Trager produced results indicating resistence and in another case from Madagascar the results indicated probable resistence, but the procedure failed in the case from Kenya. The 2 cases mark the 1st time resistence has been reported from Madagascar. In vivo tests in all cases and in vitro results in 2 cases, together with the adequate serum levels of chloroquine, confirm that malaria due to chloroquine-resistent P. falciparum is being transmitted in some parts of 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

Reviewing the literature on access to prompt and effective malaria treatment in Kenya: implications for meeting the Abuja targets

PubMed Central

Chuma, Jane; Abuya, Timothy; Memusi, Dorothy; Juma, Elizabeth; Akhwale, Willis; Ntwiga, Janet; Nyandigisi, Andrew; Tetteh, Gladys; Shretta, Rima; Amin, Abdinasir

2009-01-01

Background Effective case management is central to reducing malaria mortality and morbidity worldwide, but only a minority of those affected by malaria, have access to prompt effective treatment. In Kenya, the Division of Malaria Control is committed to ensuring that 80 percent of childhood fevers are treated with effective anti-malarial medicines within 24 hours of fever onset, but this target is largely unmet. This review aimed to document evidence on access to effective malaria treatment in Kenya, identify factors that influence access, and make recommendations on how to improve prompt access to effective malaria treatment. Since treatment-seeking patterns for malaria are similar in many settings in sub-Saharan Africa, the findings presented in this review have important lessons for other malaria endemic countries. Methods Internet searches were conducted in PUBMED (MEDLINE) and HINARI databases using specific search terms and strategies. Grey literature was obtained by soliciting reports from individual researchers working in the treatment-seeking field, from websites of major organizations involved in malaria control and from international reports. Results The review indicated that malaria treatment-seeking occurs mostly in the informal sector; that most fevers are treated, but treatment is often ineffective. Irrational drug use was identified as a problem in most studies, but determinants of this behaviour were not documented. Availability of non-recommended medicines over-the-counter and the presence of substandard anti-malarials in the market are well documented. Demand side determinants of access include perception of illness causes, severity and timing of treatment, perceptions of treatment efficacy, simplicity of regimens and ability to pay. Supply side determinants include distance to health facilities, availability of medicines, prescribing and dispensing practices and quality of medicines. Policy level factors are around the complexity and unclear

Symptomatic malaria diagnosis overestimate malaria prevalence, but underestimate anaemia burdens in children: results of a follow up study in Kenya.

PubMed

Choge, Joseph K; Magak, Ng'wena G; Akhwale, Willis; Koech, Julius; Ngeiywa, Moses M; Oyoo-Okoth, Elijah; Esamai, Fabian; Osano, Odipo; Khayeka-Wandabwa, Christopher; Kweka, Eliningaya J

2014-04-09

The commonly accepted gold standard diagnostic method for detecting malaria is a microscopic reading of Giemsa-stained blood films. However, symptomatic diagnosis remains the basis of therapeutic care for the majority of febrile patients in malaria endemic areas. This study aims to compare the discrepancy in malaria and anaemia burdens between symptomatic diagnosed patients with those diagnosed through the laboratory. Data were collected from Western Kenya during a follow-up study of 887 children with suspected cases of malaria visiting the health facilities. In the laboratory, blood samples were analysed for malaria parasite and haemoglobin levels. Differences in malaria prevalence between symptomatic diagnosis and laboratory diagnosis were analysed by Chi-square test. Bayesian probabilities were used for the approximation of the malaria and anaemia burdens. Regression analysis was applied to: (1) determine the relationships between haemoglobin levels, and malaria parasite density and (2) relate the prevalence of anaemia and the prevalence of malaria. The prevalence of malaria and anaemia ranged from 10% to 34%, being highest during the rainy seasons. The predominant malaria parasite was P. falciparum (92.3%), which occurred in higher density in children aged 2‒5 years. Fever, high temperature, sweating, shivering, vomiting and severe headache symptoms were associated with malaria during presumptive diagnosis. After conducting laboratory diagnosis, lower malaria prevalence was reported among the presumptively diagnosed patients. Surprisingly, there were no attempts to detect anaemia in the same cohort. There was a significant negative correlation between Hb levels and parasite density. We also found a positive correlation between the prevalence of anaemia and the prevalence of malaria after laboratory diagnosis indicating possible co-occurrence of malaria and anaemia. Symptomatic diagnosis of malaria overestimates malaria prevalence, but underestimates the

Use of Rapid Diagnostic Tests in Malaria School Surveys in Kenya: Does their Under-performance Matter for Planning Malaria Control?

PubMed Central

Gitonga, Caroline W.; Kihara, Jimmy H.; Njenga, Sammy M.; Awuondo, Ken; Noor, Abdisalan M.; Snow, Robert W.; Brooker, Simon J.

2012-01-01

Malaria rapid diagnostic tests (RDTs) are known to yield false-positive results, and their use in epidemiologic surveys will overestimate infection prevalence and potentially hinder efficient targeting of interventions. To examine the consequences of using RDTs in school surveys, we compared three RDT brands used during a nationwide school survey in Kenya with expert microscopy and investigated the cost implications of using alternative diagnostic approaches in identifying localities with differing levels of infection. Overall, RDT sensitivity was 96.1% and specificity was 70.8%. In terms of classifying districts and schools according to prevalence categories, RDTs were most reliable for the < 1% and > 40% categories and least reliable in the 1–4.9% category. In low-prevalence settings, microscopy was the most expensive approach, and RDT results corrected by either microscopy or polymerase chain reaction were the cheapest. Use of polymerase chain reaction–corrected RDT results is recommended in school malaria surveys, especially in settings with low-to-moderate malaria transmission. PMID:23091194

Using remote sensing environmental data to forecast malaria incidence at a rural district hospital in Western Kenya.

PubMed

Sewe, Maquins Odhiambo; Tozan, Yesim; Ahlm, Clas; Rocklöv, Joacim

2017-06-01

Malaria surveillance data provide opportunity to develop forecasting models. Seasonal variability in environmental factors correlate with malaria transmission, thus the identification of transmission patterns is useful in developing prediction models. However, with changing seasonal transmission patterns, either due to interventions or shifting weather seasons, traditional modelling approaches may not yield adequate predictive skill. Two statistical models,a general additive model (GAM) and GAMBOOST model with boosted regression were contrasted by assessing their predictive accuracy in forecasting malaria admissions at lead times of one to three months. Monthly admission data for children under five years with confirmed malaria at the Siaya district hospital in Western Kenya for the period 2003 to 2013 were used together with satellite derived data on rainfall, average temperature and evapotranspiration(ET). There was a total of 8,476 confirmed malaria admissions. The peak of malaria season changed and malaria admissions reduced overtime. The GAMBOOST model at 1-month lead time had the highest predictive skill during both the training and test periods and thus can be utilized in a malaria early warning system.

Self-treatment of malaria in a rural area of western Kenya.

PubMed Central

Ruebush, T. K.; Kern, M. K.; Campbell, C. C.; Oloo, A. J.

1995-01-01

Reported are the results of a study of residents' knowledge about malaria and antimalarial drugs and of their treatment-seeking behaviour in a rural area of western Kenya. The study subjects were generally well-informed about the symptoms of the disease. Malaria was perceived as a relatively mild illness, much less severe than acquired immunodeficiency syndrome (AIDS), measles, difficulty in breathing, and diarrhoea. Self-treatment was extremely common: of 138 episodes of febrile illness, 60% were treated at home with herbal remedies or medicines purchased at local shops, and only 18% received treatment at a health centre or hospital; no treatment was sought by the remainder. Commercially available chloroquine preparations were perceived as more effective than either antipyretics or herbal remedies for the treatment of malaria, and injections were regarded as more effective than oral medications. 4-Amino-quinolines were used to treat 58% of febrile illnesses but in only 12% of the cases was a curative dose of > or = 25 mg/kg body weight employed. Even attendance at a health centre did not ensure adequate treatment because of the common practice of sharing medication among family members. Greatly increased attention should be paid to the role of home treatment of malaria when policies are being developed for the management of febrile illnesses in sub-Saharan Africa. PMID:7743595

Modeling Malaria Vector Distribution under Climate Change Scenarios in Kenya

NASA Astrophysics Data System (ADS)

Ngaina, J. N.

2017-12-01

Projecting the distribution of malaria vectors under climate change is essential for planning integrated vector control strategies for sustaining elimination and preventing reintroduction of malaria. However, in Kenya, little knowledge exists on the possible effects of climate change on malaria vectors. Here we assess the potential impact of future climate change on locally dominant Anopheles vectors including Anopheles gambiae, Anopheles arabiensis, Anopheles merus, Anopheles funestus, Anopheles pharoensis and Anopheles nili. Environmental data (Climate, Land cover and elevation) and primary empirical geo-located species-presence data were identified. The principle of maximum entropy (Maxent) was used to model the species' potential distribution area under paleoclimate, current and future climates. The Maxent model was highly accurate with a statistically significant AUC value. Simulation-based estimates suggest that the environmentally suitable area (ESA) for Anopheles gambiae, An. arabiensis, An. funestus and An. pharoensis would increase under all two scenarios for mid-century (2016-2045), but decrease for end century (2071-2100). An increase in ESA of An. Funestus was estimated under medium stabilizing (RCP4.5) and very heavy (RCP8.5) emission scenarios for mid-century. Our findings can be applied in various ways such as the identification of additional localities where Anopheles malaria vectors may already exist, but has not yet been detected and the recognition of localities where it is likely to spread to. Moreover, it will help guide future sampling location decisions, help with the planning of vector control suites nationally and encourage broader research inquiry into vector species niche modeling

The challenges of changing national malaria drug policy to artemisinin-based combinations in Kenya.

PubMed

Amin, Abdinasir A; Zurovac, Dejan; Kangwana, Beth B; Greenfield, Joanne; Otieno, Dorothy N; Akhwale, Willis S; Snow, Robert W

2007-05-29

Sulphadoxine/sulphalene-pyrimethamine (SP) was adopted in Kenya as first line therapeutic for uncomplicated malaria in 1998. By the second half of 2003, there was convincing evidence that SP was failing and had to be replaced. Despite several descriptive investigations of policy change and implementation when countries moved from chloroquine to SP, the different constraints of moving to artemisinin-based combination therapy (ACT) in Africa are less well documented. A narrative description of the process of anti-malarial drug policy change, financing and implementation in Kenya is assembled from discussions with stakeholders, reports, newspaper articles, minutes of meetings and email correspondence between actors in the policy change process. The narrative has been structured to capture the timing of events, the difficulties and hurdles faced and the resolutions reached to the final implementation of a new treatment policy. Following a recognition that SP was failing there was a rapid technical appraisal of available data and replacement options resulting in a decision to adopt artemether-lumefantrine (AL) as the recommended first-line therapy in Kenya, announced in April 2004. Funding requirements were approved by the Global Fund to Fight AIDS, Tuberculosis and Malaria (GFATM) and over 60 million US$ were agreed in principle in July 2004 to procure AL and implement the policy change. AL arrived in Kenya in May 2006, distribution to health facilities began in July 2006 coincidental with cascade in-service training in the revised national guidelines. Both training and drug distribution were almost complete by the end of 2006. The article examines why it took over 32 months from announcing a drug policy change to completing early implementation. Reasons included: lack of clarity on sustainable financing of an expensive therapeutic for a common disease, a delay in release of funding, a lack of comparative efficacy data between AL and amodiaquine-based alternatives, a

Malaria investigation and treatment of children admitted to county hospitals in western Kenya.

PubMed

Amboko, Beatrice I; Ayieko, Philip; Ogero, Morris; Julius, Thomas; Irimu, Grace; English, Mike

2016-10-18

Up to 90 % of the global burden of malaria morbidity and mortality occurs in sub-Saharan Africa and children under-five bear a disproportionately high malaria burden. Effective inpatient case management can reduce severe malaria mortality and morbidity, but there are few reports of how successfully international and national recommendations are adopted in management of inpatient childhood malaria. A descriptive cross-sectional study of inpatient malaria case management practices was conducted using data collected over 24 months in five hospitals from high malaria risk areas participating in the Clinical Information Network (CIN) in Kenya. This study describes documented clinical features, laboratory investigations and treatment of malaria in children (2-59 months) and adherence to national guidelines. A total of 13,014 children had a malaria diagnosis on admission to the five hospitals between March, 2014 and February, 2016. Their median age was 24 months (IQR 12-36 months). The proportion with a diagnostic test for malaria requested was 11,981 (92.1 %). Of 10,388 patients with malaria test results documented, 8050 (77.5 %) were positive and anti-malarials were prescribed in 6745 (83.8 %). Malaria treatment was prescribed in 1613/2338 (69.0 %) children with a negative malaria result out of which only 52 (3.2 %) had a repeat malaria test done as recommended in national guidelines. Documentation of clinical features was good across all hospitals, but quinine remained the most prescribed malaria drug (47.2 % of positive cases) although a transition to artesunate (46.1 %) was observed. Although documented clinical features suggested approximately half of positive malaria patients were not severe cases artemether-lumefantrine was prescribed on admission in only 3.7 % cases. Despite improvements in inpatient malaria care, high rates of presumptive treatment for test negative children and likely over-use of injectable anti-malarial drugs were observed. Three

Completeness of malaria indicator data reporting via the District Health Information Software 2 in Kenya, 2011-2015.

PubMed

Githinji, Sophie; Oyando, Robinson; Malinga, Josephine; Ejersa, Waqo; Soti, David; Rono, Josea; Snow, Robert W; Buff, Ann M; Noor, Abdisalan M

2017-08-17

Health facility-based data reported through routine health information systems form the primary data source for programmatic monitoring and evaluation in most developing countries. The adoption of District Health Information Software (DHIS2) has contributed to improved availability of routine health facility-based data in many low-income countries. An assessment of malaria indicators data reported by health facilities in Kenya during the first 5 years of implementation of DHIS2, from January 2011 to December 2015, was conducted. Data on 19 malaria indicators reported monthly by health facilities were extracted from the online Kenya DHIS2 database. Completeness of reporting was analysed for each of the 19 malaria indicators and expressed as the percentage of data values actually reported over the expected number; all health facilities were expected to report data for each indicator for all 12 months in a year. Malaria indicators data were analysed for 6235 public and 3143 private health facilities. Between 2011 and 2015, completeness of reporting in the public sector increased significantly for confirmed malaria cases across all age categories (26.5-41.9%, p < 0.0001, in children aged <5 years; 30.6-51.4%, p < 0.0001, in persons aged ≥5 years). Completeness of reporting of new antenatal care (ANC) clients increased from 53.7 to 70.5%, p < 0.0001). Completeness of reporting of intermittent preventive treatment in pregnancy (IPTp) decreased from 64.8 to 53.7%, p < 0.0001 for dose 1 and from 64.6 to 53.4%, p < 0.0001 for dose 2. Data on malaria tests performed and test results were not available in DHIS2 from 2011 to 2014. In 2015, sparse data on microscopy (11.5% for children aged <5 years; 11.8% for persons aged ≥5 years) and malaria rapid diagnostic tests (RDTs) (8.1% for all ages) were reported. In the private sector, completeness of reporting increased significantly for confirmed malaria cases across all age categories (16.7-23.1%, p < 0

Malaria and anaemia among pregnant women at first antenatal clinic visit in Kisumu, western Kenya.

PubMed

Ouma, Peter; van Eijk, Anna M; Hamel, Mary J; Parise, Monica; Ayisi, John G; Otieno, Kephas; Kager, Piet A; Slutsker, Laurence

2007-12-01

To determine the prevalence of malaria and anaemia among urban and peri-urban women attending their first antenatal clinic (ANC) in an area of perennial malaria transmission. Between November 2003 and May 2004 we screened first ANC attenders for malaria and anaemia in a large urban hospital in Kisumu (western Kenya) and interviewed them to obtain demographic and medical information. Among the 685 study participants, prevalence of malaria parasitaemia was 18.0%, prevalence of any anaemia (haemoglobin < 11 g/dl) was 69.1% and prevalence of moderate anaemia was (haemoglobin < 8 g/dl) 11.8%. Sixteen women were hospitalized during pregnancy, eight because of malaria. In multivariate analysis, young age, living in a house with mud walls, a visit to rural area, peri-urban residence, second trimester of pregnancy and Luo ethnicity were significant risk factors for malaria parasitaemia. Malaria was an important risk factor for any and moderate anaemia; use of an insecticide-treated net (ITN) was a protective factor for any anaemia. Married women with a higher level of education, better-quality housing and full-time employment were more likely to use an ITN. Malaria and anaemia are established problems by the time of the first ANC visit. Mechanisms to deliver ITNs to women of child-bearing age before they become pregnant need to be explored. Early ANC visits are warranted in order for women to benefit from policies aimed at reducing the burden of malaria and anaemia.

A cross-sectional study of malaria endemicity and health system readiness to deliver services in Kenya, Namibia and Senegal.

PubMed

Lee, Elizabeth H; Olsen, Cara H; Koehlmoos, Tracey; Masuoka, Penny; Stewart, Ann; Bennett, Jason W; Mancuso, James

2017-11-01

Despite good progress towards elimination, malaria continues to contribute substantially to the sub-Saharan African disease burden. Sustaining previous gains requires continued readiness to deliver malaria services in response to actual disease burden, which in turn contributes to health systems strengthening. This study investigates a health system innovation. We examined whether malaria prevalence, or endemicity, is a driver of health facility readiness to deliver malaria services. To estimate this association, we geo-linked cross-sectional facility survey data to endemicity data for Kenya, Namibia and Senegal. We tested the validity and reliability of the primary study outcome, the malaria service readiness index and mapped service readiness components in a geographic information system. We conducted a weighted multivariable linear regression analysis of the relationship between endemicity and malaria service readiness, stratified for urban or rural facility location. As endemicity increased in rural areas, there was a concurrent, modest increase in service readiness at the facility level [β: 0.028; (95% CI 0.008, 0.047)], whereas no relationship existed in urban settings. Private-for-profit facilities were generally less prepared than public [β: -0.102; (95% CI - 0.154, -0.050)]. Most facilities had the necessary supplies to diagnose malaria, yet availability of malaria guidelines and adequately trained staff as well as medicines and commodities varied. Findings require cautious interpretation outside the study sample, which was a more limited subset of the original surveys' sampling schemes. Our approach and findings may be used by national malaria programs to identify low performing facilities in malarious areas for targeted service delivery interventions. This study demonstrates use of existing data sources to evaluate health system performance and to identify within- and cross-country variations for targeted interventions. Published by Oxford

The malaria testing and treatment landscape in Kenya: results from a nationally representative survey among the public and private sector in 2016.

PubMed

Musuva, Anne; Ejersa, Waqo; Kiptui, Rebecca; Memusi, Dorothy; Abwao, Edward

2017-12-21

Since 2004, Kenya's national malaria treatment guidelines have stipulated artemisinin-based combination therapy (ACT) as first-line treatment for uncomplicated malaria, and since 2014, confirmatory diagnosis of malaria in all cases before treatment has been recommended. A number of strategies to support national guidelines have been implemented in the public and private sectors in recent years. A nationally-representative malaria outlet survey, implemented across four epidemiological zones, was conducted between June and August 2016 to provide practical evidence to inform strategies and policies in Kenya towards achieving national malaria control goals. A total of 17,852 outlets were screened and 2271 outlets were eligible and interviewed. 78.3% of all screened public health facilities stocked both malaria diagnostic testing and quality-assured ACT (QAACT). Sulfadoxine-pyrimethamine (SP) for intermittent preventive treatment in pregnancy was available in 70% of public health facilities in endemic areas where it is recommended for treatment. SP was rarely found in the public sector outside of the endemic areas (< 0.5%). The anti-malaria stocking private sector had lower levels of QAACT (46.7%) and malaria blood testing (20.8%) availability but accounted for majority of anti-malarial distribution (70.6% of the national market share). More than 40% of anti-malarials were distributed by unregistered pharmacies (37.3%) and general retailers (7.1%). QAACT accounted for 58.2% of the total anti-malarial market share, while market share for non-QAACT was 15.8% and for SP, 24.8%. In endemic areas, 74.9% of anti-malarials distributed were QAACT. Elsewhere, QAACT market share was 49.4% in the endemic-prone areas, 33.2% in seasonal-transmission areas and 37.9% in low-risk areas. Although public sector availability of QAACT and malaria diagnosis is relatively high, there is a gap in availability of both testing and treatment that must be addressed. The private sector in Kenya

Establishing a malaria diagnostics centre of excellence in Kisumu, Kenya.

PubMed

Ohrt, Colin; Obare, Peter; Nanakorn, Ampon; Adhiambo, Christine; Awuondo, Ken; O'Meara, Wendy Prudhomme; Remich, Shon; Martin, Kurt; Cook, Earnest; Chretien, Jean-Paul; Lucas, Carmen; Osoga, Joseph; McEvoy, Peter; Owaga, Martin Lucas; Odera, James Sande; Ogutu, Bernhards

2007-06-12

Malaria microscopy, while the gold standard for malaria diagnosis, has limitations. Efficacy estimates in drug and vaccine malaria trials are very sensitive to small errors in microscopy endpoints. This fact led to the establishment of a Malaria Diagnostics Centre of Excellence in Kisumu, Kenya. The primary objective was to ensure valid clinical trial and diagnostic test evaluations. Key secondary objectives were technology transfer to host countries, establishment of partnerships, and training of clinical microscopists. A twelve-day "long" and a four-day "short" training course consisting of supervised laboratory practicals, lectures, group discussions, demonstrations, and take home assignments were developed. Well characterized slides were developed and training materials iteratively improved. Objective pre- and post-course evaluations consisted of 30 slides (19 negative, 11 positive) with a density range of 50-660 parasites/mul, a written examination (65 questions), a photographic image examination (30 images of artifacts and species specific characteristics), and a parasite counting examination. To date, 209 microscopists have participated from 11 countries. Seventy-seven experienced microscopists participated in the "long" courses, including 47 research microscopists. Sensitivity improved by a mean of 14% (CI 9-19%) from 77% baseline (CI 73-81 %), while specificity improved by a mean of 17% (CI 11-23%) from 76% (CI 70-82%) baseline. Twenty-three microscopists who had been selected for a four-day refresher course showed continued improvement with a mean final sensitivity of 95% (CI 91-98%) and specificity of 97% (CI 95-100%). Only 9% of those taking the pre-test in the "long" course achieved a 90% sensitivity and 95% specificity, which increased to 61% of those completing the "short" course. All measures of performance improved substantially across each of the five organization types and in each course offered. The data clearly illustrated that false positive

Habitat stability and occurrences of malaria vector larvae in western Kenya highlands.

PubMed

Himeidan, Yousif E; Zhou, Guofa; Yakob, Laith; Afrane, Yaw; Munga, Stephen; Atieli, Harrysone; El-Rayah, El-Amin; Githeko, Andrew K; Yan, Guiyun

2009-10-21

Although the occurrence of malaria vector larvae in the valleys of western Kenya highlands is well documented, knowledge of larval habitats in the uphill sites is lacking. Given that most inhabitants of the highlands actually dwell in the uphill regions, it is important to develop understanding of mosquito breeding habitat stability in these sites in order to determine their potential for larval control. A total of 128 potential larval habitats were identified in hilltops and along the seasonal streams in the Sigalagala area of Kakamega district, western Kenya. Water availability in the habitats was followed up daily from August 3, 2006 to February 23, 2007. A habitat is defined as stable when it remains aquatic continuously for at least 12 d. Mosquito larvae were observed weekly. Frequencies of aquatic, stable and larvae positive habitats were compared between the hilltop and seasonal stream area using chi2-test. Factors affecting the presence/absence of Anopheles gambiae larvae in the highlands were determined using multiple logistic regression analysis. Topography significantly affected habitat availability and stability. The occurrence of aquatic habitats in the hilltop was more sporadic than in the stream area. The percentage of habitat occurrences that were classified as stable during the rainy season is 48.76% and 80.79% respectively for the hilltop and stream area. Corresponding frequencies of larvae positive habitats were 0% in the hilltop and 5.91% in the stream area. After the rainy season, only 23.42% of habitat occurrences were stable and 0.01% larvae positive habitats were found in the hilltops, whereas 89.75% of occurrences remained stable in the stream area resulting in a frequency of 12.21% larvae positive habitats. The logistic regression analysis confirmed the association between habitat stability and larval occurrence and indicated that habitat surface area was negatively affecting the occurrence of An. gambiae larvae. While An. gambiae and An

Expanding Access to Malaria Diagnosis through Retail Shops in Western Kenya: What Do Shop Workers Think?

PubMed

Rusk, Andria; Goodman, Catherine; Naanyu, Violet; Koech, Beatrice; Obala, Andrew; O'Meara, Wendy Prudhomme

2013-01-01

Background. The common symptoms of malaria reduce the specificity of clinical diagnosis. Presumptive treatment is conventional but can lead to overdiagnosis of malaria, delay of appropriate treatment, overprescription of antimalarials, and drug resistance. Routine use of diagnostic tests can address many of these concerns. Though treatment is often procured from retailers, there is low availability of rapid diagnostic tests for malaria (MRDTs), a simple, inexpensive, and accurate diagnostic solution. We know little about the challenges to expanding access to diagnostics through these outlets. Methods. To understand the perceptions of the benefits and challenges to selling rapid diagnostic tests for malaria, we conducted focus group discussions with antimalarial retailers who serve the residents of the Webuye Health and Demographic Surveillance Site in western Kenya. Results. Medicine retailers perceived MRDTs to be beneficial to their customers and businesses but also included cost, fear of the tests, risks of self-treatment, and regulatory concerns among the challenges to using and selling MRDTs. Conclusion. MRDTs represent a viable approach to increase access to malaria diagnostic testing. Medicine retailers are eager for MRDTs to be made available to them. However, certain challenges remain to implementation in retail outlets and should be addressed in advance.

In-vivo efficacy of amodiaquine-artesunate in children with uncomplicated Plasmodium falciparum malaria in western Kenya

PubMed Central

Thwing, J. I.; Odero, C. O.; Odhiambo, F. O.; Otieno, K. O.; Kariuki, S.; Ord, R.; Roper, C.; McMorrow, M.; Vulule, J.; Slutsker, L.; Newman, R. D.; Hamel, M. J.; Desai, M.

2018-01-01

Summary OBJECTIVES To assess the efficacy of amodiaquine-artesunate in an area with high chloroquine resistance in western Kenya. METHODS Twenty-eight day in-vivo efficacy trial of amodiaquine-artesunate in 103 children aged 6–59 months in western Kenya with smear-confirmed uncomplicated Plasmodium falciparum malaria. RESULTS The 28-day uncorrected adequate clinical and parasitological response (ACPR) was 69.0%, with 15.5% Late Clinical Failure and 15.5% Late Parasitologic Failure rates. The PCR-corrected 28-day ACPR was 90.2%. Clinical risk factors for recurrent infection (recrudescences and reinfections) were lower axillary temperature at enrolment and low weight-for-age Z-score. The presence of single nucleotide polymorphisms pfcrt 76T and pfmdr1 86Y at baseline was associated with increased risk of recurrent infections, both reinfections and recrudescences. CONCLUSION Although artemether-lumefantrine (Coartem®) is the first line ACT in Kenya, amodiaquine-artesunate is registered as an option for treatment of uncomplicated P. falciparum and remains an effective alternative to Coartem® in western Kenya. Continued amodiaquine monotherapy in the private sector may jeopardise the future use of amodiaquine-artesunate as an alternative artemisinin-based combination therapy. PMID:19187521

Gender roles and perceptions of malaria risk in agricultural communities of Mwea Division in Central Kenya.

PubMed

Woldu, Dawit Okubatsion; Haile, Zelalem Teka

2015-01-01

We examined gender differences in the perception of high malaria risk in women and factors associated with a high number of malaria episodes in the Mwea Division of Central Kenya. Ethnographic and successive free listing interviews (an open-ended data collection technique used to show the relation of items in a given domain) with 53 key informants and structured interviews conducted from June to October 2010 with 250 respondents who represented the socioeconomic and geographical diversity of the area were analyzed. Qualitative text analysis and inferential statistics were employed. While a greater proportion of men (51.6%) attributed women's high malaria risk to their "biological weakness," most women believed that their high malaria risk was related to their role in the agricultural fields (43.6%) and to their household responsibilities (23.1%). Compared to men, women were more likely to work in wet aspects of agricultural activities (χ(2) (2, N = 153) = 13.47, p < .01). Women were nearly twice as likely as men to report high episodes of malaria (adjusted odds ratio: 2.54; 95% confidence interval: 1.05-6.15). Culturally prescribed gender roles in agricultural communities in Mwea may play an important role in explaining disparity in reported malaria incidence. While identification of ecological and economic determinants of malaria is important, gender-based research can make a significant contribution to the development of effective and sustainable malaria reduction strategies.

Malaria and human immunodeficiency virus infection as risk factors for anemia in infants in Kisumu, western Kenya.

PubMed

van Eijk, Anna M; Ayisi, John G; Ter Kuile, Feiko O; Misore, Ambrose O; Otieno, Juliana A; Kolczak, Margarette S; Kager, Piet A; Steketee, Richard W; Nahlen, Bernard L

2002-07-01

The role of maternal and pediatric infection with human immunodeficiency virus type 1 (HIV-1) and malaria as risk factors for anemia was determined in a birth cohort of infants born to mothers participating in a study of the interaction between placental malaria and HIV infection, in Kisumu, Kenya. Between June 1996 and April 2000, 661 infants born to 467 HIV-seropositive and 194 HIV-seronegative mothers were monitored monthly from birth. At each visit a questionnaire was completed and a blood sample was collected for the determination of hemoglobin levels and detection of malaria and HIV. Anemia was common and increased from 13.6% at one month to 75% at six months and remained high throughout the second half of infancy. Placental malaria, infant malaria, and HIV infection of the infant were all associated with infant anemia in a multivariate model, adjusting for other co-variates found to be associated with infant anemia. The HIV-infected infants with malaria parasitemia had lower mean hemoglobin levels compared with HIV-uninfected infants, or HIV-infected infants without malaria, suggesting that HIV-infected infants are particularly vulnerable to the adverse consequences of malaria at this age. Early detection and prompt treatment of infant malaria and treatment of anemia as part of the study protocol failed to prevent most of the infants from becoming anemic. Although not proven effective in this study, micronutrient supplementation should be prospectively assessed in HIV-infected infants as a means of preventing anemia.

Evaluation of a laboratory quality assurance pilot programme for malaria diagnostics in low-transmission areas of Kenya, 2013.

PubMed

Wanja, Elizabeth; Achilla, Rachel; Obare, Peter; Adeny, Rose; Moseti, Caroline; Otieno, Victor; Morang'a, Collins; Murigi, Ephantus; Nyamuni, John; Monthei, Derek R; Ogutu, Bernhards; Buff, Ann M

2017-05-25

One objective of the Kenya National Malaria Strategy 2009-2017 is scaling access to prompt diagnosis and effective treatment. In 2013, a quality assurance (QA) pilot was implemented to improve accuracy of malaria diagnostics at selected health facilities in low-transmission counties of Kenya. Trends in malaria diagnostic and QA indicator performance during the pilot are described. From June to December 2013, 28 QA officers provided on-the-job training and mentoring for malaria microscopy, malaria rapid diagnostic tests and laboratory QA/quality control (QC) practices over four 1-day visits at 83 health facilities. QA officers observed and recorded laboratory conditions and practices and cross-checked blood slides for malaria parasite presence, and a portion of cross-checked slides were confirmed by reference laboratories. Eighty (96%) facilities completed the pilot. Among 315 personnel at pilot initiation, 13% (n = 40) reported malaria diagnostics training within the previous 12 months. Slide positivity ranged from 3 to 7%. Compared to the reference laboratory, microscopy sensitivity ranged from 53 to 96% and positive predictive value from 39 to 53% for facility staff and from 60 to 96% and 52 to 80%, respectively, for QA officers. Compared to reference, specificity ranged from 88 to 98% and negative predictive value from 98 to 99% for health-facility personnel and from 93 to 99% and 99%, respectively, for QA officers. The kappa value ranged from 0.48-0.66 for facility staff and 0.57-0.84 for QA officers compared to reference. The only significant test performance improvement observed for facility staff was for specificity from 88% (95% CI 85-90%) to 98% (95% CI 97-99%). QA/QC practices, including use of positive-control slides, internal and external slide cross-checking and recording of QA/QC activities, all increased significantly across the pilot (p < 0.001). Reference material availability also increased significantly; availability of six microscopy job

Spatial clustering of malaria and associated risk factors during an epidemic in a highland area of western Kenya.

PubMed

Brooker, Simon; Clarke, Siân; Njagi, Joseph Kiambo; Polack, Sarah; Mugo, Benbolt; Estambale, Benson; Muchiri, Eric; Magnussen, Pascal; Cox, Jonathan

2004-07-01

The epidemiology of malaria over small areas remains poorly understood, and this is particularly true for malaria during epidemics in highland areas of Africa, where transmission intensity is low and characterized by acute within and between year variations. We report an analysis of the spatial distribution of clinical malaria during an epidemic and investigate putative risk factors. Active case surveillance was undertaken in three schools in Nandi District, Western Kenya for 10 weeks during a malaria outbreak in May-July 2002. Household surveys of cases and age-matched controls were conducted to collect information on household construction, exposure factors and socio-economic status. Household geographical location and altitude were determined using a hand-held geographical positioning system and landcover types were determined using high spatial resolution satellite sensor data. Among 129 cases identified during the surveillance, which were matched to 155 controls, we identified significant spatial clusters of malaria cases as determined using the spatial scan statistic. Conditional multiple logistic regression analysis showed that the risk of malaria was higher in children who were underweight, who lived at lower altitudes, and who lived in households where drugs were not kept at home. Copyright 2004 Blackwell Publishing Ltd

Impact of Intermittent Screening and Treatment for Malaria among School Children in Kenya: A Cluster Randomised Trial

PubMed Central

Halliday, Katherine E.; Okello, George; Turner, Elizabeth L.; Njagi, Kiambo; Mcharo, Carlos; Kengo, Juddy; Allen, Elizabeth; Dubeck, Margaret M.; Jukes, Matthew C. H.; Brooker, Simon J.

2014-01-01

Background Improving the health of school-aged children can yield substantial benefits for cognitive development and educational achievement. However, there is limited experimental evidence of the benefits of alternative school-based malaria interventions or how the impacts of interventions vary according to intensity of malaria transmission. We investigated the effect of intermittent screening and treatment (IST) for malaria on the health and education of school children in an area of low to moderate malaria transmission. Methods and Findings A cluster randomised trial was implemented with 5,233 children in 101 government primary schools on the south coast of Kenya in 2010–2012. The intervention was delivered to children randomly selected from classes 1 and 5 who were followed up for 24 months. Once a school term, children were screened by public health workers using malaria rapid diagnostic tests (RDTs), and children (with or without malaria symptoms) found to be RDT-positive were treated with a six dose regimen of artemether-lumefantrine (AL). Given the nature of the intervention, the trial was not blinded. The primary outcomes were anaemia and sustained attention. Secondary outcomes were malaria parasitaemia and educational achievement. Data were analysed on an intention-to-treat basis. During the intervention period, an average of 88.3% children in intervention schools were screened at each round, of whom 17.5% were RDT-positive. 80.3% of children in the control and 80.2% in the intervention group were followed-up at 24 months. No impact of the malaria IST intervention was observed for prevalence of anaemia at either 12 or 24 months (adjusted risk ratio [Adj.RR]: 1.03, 95% CI 0.93–1.13, p = 0.621 and Adj.RR: 1.00, 95% CI 0.90–1.11, p = 0.953) respectively, or on prevalence of P. falciparum infection or scores of classroom attention. No effect of IST was observed on educational achievement in the older class, but an apparent negative effect was

Brine shrimp toxicity and antimalarial activity of some plants traditionally used in treatment of malaria in Msambweni district of Kenya.

PubMed

Nguta, J M; Mbaria, J M

2013-07-30

In Kenya, most people especially in rural areas use traditional medicine and medicinal plants to treat many diseases including malaria. Malaria is of national concern in Kenya, in view of development of resistant strains of Plasmodium falciparum to drugs especially chloroquine, which had been effective and affordable. There is need for alternative and affordable therapy. Many antimalarial drugs have been derived from medicinal plants and this is evident from the reported antiplasmodial activity. The present study reports on the in vivo antimalarial activity and brine shrimp lethality of five medicinal plants traditionally used to treat malaria in Msambweni district, Kenya. A total of five aqueous crude extracts from different plant parts used in traditional medicine for the treatment of malaria were evaluated for their in vivo antimalarial activity using Plasmodium berghei infected Swiss mice and for their acute toxicity using Brine shrimp lethality test. The screened crude plant extracts suppressed parasitaemia as follows: Azadirachta indica (L) Burm. (Meliaceae), 3.1%; Dichrostachys cinerea (L) Wight et Arn (Mimosaceae), 6.3%; Tamarindus indica L. (Caesalpiniaceae), 25.1%; Acacia seyal Del. (Mimosaceae) 27.8% and Grewia trichocarpa Hochst ex A.Rich (Tiliaceae) 35.8%. In terms of toxicity, A.indica root bark extract had an LC50 of 285.8 µg/ml and was considered moderately toxic. T.indica stem bark extract and G.trichocarpa root extract had an LC50 of 516.4 and 545.8 µg/ml respectively and were considered to be weakly toxic while A.seyal and D.cinerea root extracts had a LC50>1000 µg/ml and were therefore considered to be non toxic. The results indicate that the aqueous extracts of the tested plants when used alone as monotherapy had antimalarial activity which was significantly different from that of chloroquine (P≤0.05). The results also suggest that the anecdotal efficacy of the above plants reported by the study community is related to synergism of

Expanding Access to Malaria Diagnosis through Retail Shops in Western Kenya: What Do Shop Workers Think?

PubMed Central

Koech, Beatrice; Obala, Andrew; O'Meara, Wendy Prudhomme

2013-01-01

Background. The common symptoms of malaria reduce the specificity of clinical diagnosis. Presumptive treatment is conventional but can lead to overdiagnosis of malaria, delay of appropriate treatment, overprescription of antimalarials, and drug resistance. Routine use of diagnostic tests can address many of these concerns. Though treatment is often procured from retailers, there is low availability of rapid diagnostic tests for malaria (MRDTs), a simple, inexpensive, and accurate diagnostic solution. We know little about the challenges to expanding access to diagnostics through these outlets. Methods. To understand the perceptions of the benefits and challenges to selling rapid diagnostic tests for malaria, we conducted focus group discussions with antimalarial retailers who serve the residents of the Webuye Health and Demographic Surveillance Site in western Kenya. Results. Medicine retailers perceived MRDTs to be beneficial to their customers and businesses but also included cost, fear of the tests, risks of self-treatment, and regulatory concerns among the challenges to using and selling MRDTs. Conclusion. MRDTs represent a viable approach to increase access to malaria diagnostic testing. Medicine retailers are eager for MRDTs to be made available to them. However, certain challenges remain to implementation in retail outlets and should be addressed in advance. PMID:23766923

Impact of insecticide-treated bed nets on malaria transmission indices on the south coast of Kenya

PubMed Central

2011-01-01

Background Besides significantly reducing malaria vector densities, prolonged usage of bed nets has been linked to decline of Anopheles gambiae s.s. relative to Anopheles arabiensis, changes in host feeding preference of malaria vectors, and behavioural shifts to exophagy (outdoor biting) for the two important malaria vectors in Africa, An. gambiae s.l. and Anopheles funestus. In southern coastal Kenya, bed net use was negligible in 1997-1998 when Anopheles funestus and An. gambiae s.s. were the primary malaria vectors, with An. arabiensis and Anopheles merus playing a secondary role. Since 2001, bed net use has increased progressively and reached high levels by 2009-2010 with corresponding decline in malaria transmission. Methods To evaluate the impact of the substantial increase in household bed net use within this area on vector density, vector composition, and human-vector contact, indoor and outdoor resting mosquitoes were collected in the same region during 2009-2010 using pyrethrum spray catches and clay pots for indoor and outdoor collections respectively. Information on bed net use per sleeping spaces and factors influencing mosquito density were determined in the same houses using Poisson regression analysis. Species distribution was determined, and number of mosquitoes per house, human-biting rates (HBR), and entomological inoculation rate (EIR) were compared to those reported for the same area during 1997-1998, when bed net coverage had been minimal. Results Compared to 1997-1998, a significant decline in the relative proportion of An. gambiae s.s. among collected mosquitoes was noted, coupled with a proportionate increase of An. arabiensis. Following > 5 years of 60-86% coverage with bed nets, the density, human biting rate and EIR of indoor resting mosquitoes were reduced by more than 92% for An. funestus and by 75% for An. gambiae s.l. In addition, the host feeding choice of both vectors shifted more toward non-human vertebrates. Besides bed net use

Establishing a malaria diagnostics centre of excellence in Kisumu, Kenya

PubMed Central

Ohrt, Colin; Obare, Peter; Nanakorn, Ampon; Adhiambo, Christine; Awuondo, Ken; O'Meara, Wendy Prudhomme; Remich, Shon; Martin, Kurt; Cook, Earnest; Chretien, Jean-Paul; Lucas, Carmen; Osoga, Joseph; McEvoy, Peter; Owaga, Martin Lucas; Odera, James Sande; Ogutu, Bernhards

2007-01-01

Background Malaria microscopy, while the gold standard for malaria diagnosis, has limitations. Efficacy estimates in drug and vaccine malaria trials are very sensitive to small errors in microscopy endpoints. This fact led to the establishment of a Malaria Diagnostics Centre of Excellence in Kisumu, Kenya. The primary objective was to ensure valid clinical trial and diagnostic test evaluations. Key secondary objectives were technology transfer to host countries, establishment of partnerships, and training of clinical microscopists. Case description A twelve-day "long" and a four-day "short" training course consisting of supervised laboratory practicals, lectures, group discussions, demonstrations, and take home assignments were developed. Well characterized slides were developed and training materials iteratively improved. Objective pre- and post-course evaluations consisted of 30 slides (19 negative, 11 positive) with a density range of 50–660 parasites/μl, a written examination (65 questions), a photographic image examination (30 images of artifacts and species specific characteristics), and a parasite counting examination. Discussion and Evaluation To date, 209 microscopists have participated from 11 countries. Seventy-seven experienced microscopists participated in the "long" courses, including 47 research microscopists. Sensitivity improved by a mean of 14% (CI 9–19%) from 77% baseline (CI 73–81 %), while specificity improved by a mean of 17% (CI 11–23%) from 76% (CI 70–82%) baseline. Twenty-three microscopists who had been selected for a four-day refresher course showed continued improvement with a mean final sensitivity of 95% (CI 91–98%) and specificity of 97% (CI 95–100%). Only 9% of those taking the pre-test in the "long" course achieved a 90% sensitivity and 95% specificity, which increased to 61% of those completing the "short" course. All measures of performance improved substantially across each of the five organization types and in

Assessment of Malaria Reporting and Epidemic Preparedness Systems in Health Facilities in Eldoret West District, Uasin Gishu County, Kenya

PubMed Central

Kirinyet, Ruth C.; Juma, Ahmad

2016-01-01

The most important factor in reducing the impact of an epidemic is a timely response with implementation of effective control measures at the point of detection. This study sought to assess the malaria reporting and epidemic preparedness systems of health facilities in Eldoret West District, Kenya. A cross-sectional study design was adapted. A census technique was used to select all the forty five health facilities in the district comprising of government, mission and non-governmental facilities. An interviewer administered questionnaire was used for data collection and analysis done using Stata. Categorical variables were summarized as frequencies and corresponding percentages. The overall reporting rate was 91.7% for all the health facilities. Only 15 health facilities (33%) plotted malaria trend lines for number of cases of malaria. Malaria epidemics were reported within 24 hours in 22 health facilities but they lacked the appropriate supplies to respond to confirmed cases or epidemics. The overall malaria reporting completeness rate was above 90% implying that the malaria surveillance system was generally good. Concerted efforts by concerned stakeholders should ensure improvement of malaria epidemic preparedness system in all health facilities and provision of information to health personnel on malaria outbreak response strategies. PMID:28299154

Predicting key malaria transmission factors, biting and entomological inoculation rates, using modelled soil moisture in Kenya.

PubMed

Patz, J A; Strzepek, K; Lele, S; Hedden, M; Greene, S; Noden, B; Hay, S I; Kalkstein, L; Beier, J C

1998-10-01

While malaria transmission varies seasonally, large inter-annual heterogeneity of malaria incidence occurs. Variability in entomological parameters, biting rates and entomological inoculation rates (EIR) have been strongly associated with attack rates in children. The goal of this study was to assess the weather's impact on weekly biting and EIR in the endemic area of Kisian, Kenya. Entomological data collected by the U.S. Army from March 1986 through June 1988 at Kisian, Kenya was analysed with concurrent weather data from nearby Kisumu airport. A soil moisture model of surface-water availability was used to combine multiple weather parameters with landcover and soil features to improve disease prediction. Modelling soil moisture substantially improved prediction of biting rates compared to rainfall; soil moisture lagged two weeks explained up to 45% of An. gambiae biting variability, compared to 8% for raw precipitation. For An. funestus, soil moisture explained 32% variability, peaking after a 4-week lag. The interspecies difference in response to soil moisture was significant (P < 0.00001). A satellite normalized differential vegetation index (NDVI) of the study site yielded a similar correlation (r = 0.42 An. gambiae). Modelled soil moisture accounted for up to 56% variability of An. gambiae EIR, peaking at a lag of six weeks. The relationship between temperature and An. gambiae biting rates was less robust; maximum temperature r2 = -0.20, and minimum temperature r2 = 0.12 after lagging one week. Benefits of hydrological modelling are compared to raw weather parameters and to satellite NDVI. These findings can improve both current malaria risk assessments and those based on El Niño forecasts or global climate change model projections.

Lessons learnt from the first controlled human malaria infection study conducted in Nairobi, Kenya.

PubMed

Hodgson, Susanne H; Juma, Elizabeth; Salim, Amina; Magiri, Charles; Njenga, Daniel; Molyneux, Sassy; Njuguna, Patricia; Awuondo, Ken; Lowe, Brett; Billingsley, Peter F; Cole, Andrew O; Ogwang, Caroline; Osier, Faith; Chilengi, Roma; Hoffman, Stephen L; Draper, Simon J; Ogutu, Bernhards; Marsh, Kevin

2015-04-28

Controlled human malaria infection (CHMI) studies, in which healthy volunteers are infected with Plasmodium falciparum to assess the efficacy of novel malaria vaccines and drugs, have become a vital tool to accelerate vaccine and drug development. CHMI studies provide a cost-effective and expeditious way to circumvent the use of large-scale field efficacy studies to deselect intervention candidates. However, to date few modern CHMI studies have been performed in malaria-endemic countries. An open-label, randomized pilot CHMI study was conducted using aseptic, purified, cryopreserved, infectious P. falciparum sporozoites (SPZ) (Sanaria® PfSPZ Challenge) administered intramuscularly (IM) to healthy Kenyan adults (n = 28) with varying degrees of prior exposure to P. falciparum. The purpose of the study was to establish the PfSPZ Challenge CHMI model in a Kenyan setting with the aim of increasing the international capacity for efficacy testing of malaria vaccines and drugs, and allowing earlier assessment of efficacy in a population for which interventions are being developed. This was part of the EDCTP-funded capacity development of the CHMI platform in Africa. This paper discusses in detail lessons learnt from conducting the first CHMI study in Kenya. Issues pertinent to the African setting, including community sensitization, consent and recruitment are considered. Detailed reasoning regarding the study design (for example, dose and route of administration of PfSPZ Challenge, criteria for grouping volunteers according to prior exposure to malaria and duration of follow-up post CHMI) are given and changes other centres may want to consider for future studies are suggested. Performing CHMI studies in an African setting presents unique but surmountable challenges and offers great opportunity for acceleration of malaria vaccine and drug development. The reflections in this paper aim to aid other centres and partners intending to use the CHMI model in Africa.

Major improvements in the quality of malaria case-management under the "test and treat" policy in Kenya.

PubMed

Zurovac, Dejan; Githinji, Sophie; Memusi, Dorothy; Kigen, Samuel; Machini, Beatrice; Muturi, Alex; Otieno, Gabriel; Snow, Robert W; Nyandigisi, Andrew

2014-01-01

Monitoring implementation of the "test and treat" case-management policy for malaria is an important component of all malaria control programmes in Africa. Unfortunately, routine information systems are commonly deficient to provide necessary information. Using health facility surveys we monitored health systems readiness and malaria case-management practices prior to and following implementation of the 2010 "test and treat" policy in Kenya. Between 2010 and 2013 six national, cross-sectional, health facility surveys were undertaken. The number of facilities assessed ranged between 172 and 176, health workers interviewed between 216 and 237 and outpatient consultations for febrile patients evaluated between 1,208 and 2,408 across six surveys. Comparing baseline and the last survey results, all readiness indicators showed significant (p<0.005) improvements: availability of parasitological diagnosis (55.2% to 90.7%); RDT availability (7.5% to 69.8%); total artemether-lumefantrine (AL) stock-out (27.2% to 7.0%); stock-out of one or more AL packs (59.5% to 21.6%); training coverage (0 to 50.2%); guidelines access (0 to 58.1%) and supervision (17.9% to 30.8%). Testing increased by 34.0% (23.9% to 57.9%; p<0.001) while testing and treatment according to test result increased by 34.2% (15.7% to 49.9%; p<0.001). Treatment adherence for test positive patients improved from 83.3% to 90.3% (p = 0.138) and for test negative patients from 47.9% to 83.4% (p<0.001). Significant testing and treatment improvements were observed in children and adults. There was no difference in practices with respect to the type and result of malaria test (RDT vs microscopy). Of eight dosing, dispensing and counseling tasks, improvements were observed for four tasks. Overall AL use for febrile patients decreased from 63.5% to 35.6% (p<0.001). Major improvements in the implementation of "test and treat" policy were observed in Kenya. Some gaps towards universal targets still remained. Other

Modeling the Financial and Clinical Implications of Malaria Rapid Diagnostic Tests in the Case-management of Older Children and Adults in Kenya

PubMed Central

Zurovac, Dejan; Larson, Bruce A.; Skarbinski, Jacek; Slutsker, Laurence; Snow, Robert W.; Hamel, Mary J.

2008-01-01

Using data on clinical practices for outpatients 5 years and older, test accuracy, and malaria prevalence, we model financial and clinical implications of malaria rapid diagnostic tests (RDTs) under the new artemether-lumefantrine (AL) treatment policy in one high and one low malaria prevalence district in Kenya. In the high transmission district, RDTs as actually used would improve malaria treatment (61% less over-treatment but 8% more under-treatment) and lower costs (21% less). Nonetheless, the majority of patients with malaria would not be correctly treated with AL. In the low transmission district, especially because the treatment policy was new and AL was not widely used, RDTs as actually used would yield a minor reduction in under-treatment errors (36% less but the base is small) with 41% higher costs. In both districts, adherence to revised clinical practices with RDTs has the potential to further decrease treatment errors with acceptable costs. PMID:18541764

Community-based intermittent mass testing and treatment for malaria in an area of high transmission intensity, western Kenya: study design and methodology for a cluster randomized controlled trial.

PubMed

Samuels, Aaron M; Awino, Nobert; Odongo, Wycliffe; Abong'o, Benard; Gimnig, John; Otieno, Kephas; Shi, Ya Ping; Were, Vincent; Allen, Denise Roth; Were, Florence; Sang, Tony; Obor, David; Williamson, John; Hamel, Mary J; Patrick Kachur, S; Slutsker, Laurence; Lindblade, Kim A; Kariuki, Simon; Desai, Meghna

2017-06-07

Most human Plasmodium infections in western Kenya are asymptomatic and are believed to contribute importantly to malaria transmission. Elimination of asymptomatic infections requires active treatment approaches, such as mass testing and treatment (MTaT) or mass drug administration (MDA), as infected persons do not seek care for their infection. Evaluations of community-based approaches that are designed to reduce malaria transmission require careful attention to study design to ensure that important effects can be measured accurately. This manuscript describes the study design and methodology of a cluster-randomized controlled trial to evaluate a MTaT approach for malaria transmission reduction in an area of high malaria transmission. Ten health facilities in western Kenya were purposively selected for inclusion. The communities within 3 km of each health facility were divided into three clusters of approximately equal population size. Two clusters around each health facility were randomly assigned to the control arm, and one to the intervention arm. Three times per year for 2 years, after the long and short rains, and again before the long rains, teams of community health volunteers visited every household within the intervention arm, tested all consenting individuals with malaria rapid diagnostic tests, and treated all positive individuals with an effective anti-malarial. The effect of mass testing and treatment on malaria transmission was measured through population-based longitudinal cohorts, outpatient visits for clinical malaria, periodic population-based cross-sectional surveys, and entomological indices.

A cohort study of Plasmodium falciparum malaria in pregnancy and associations with uteroplacental blood flow and fetal anthropometrics in Kenya.

PubMed

McClure, Elizabeth M; Meshnick, Steven R; Lazebnik, Noam; Mungai, Peter; King, Christopher L; Hudgens, Michael; Goldenberg, Robert L; Siega-Riz, Anna-Maria; Dent, Arlene E

2014-07-01

To use ultrasound to explore the impact of malaria in pregnancy on fetal growth and newborn outcomes among a cohort of women enrolled in an intermittent presumptive treatment in pregnancy (IPTp) with sulfadoxine/pyrimethamine (SP) program in coastal Kenya. Enrolled women were tested for malaria at first prenatal care visit, and physical and ultrasound examinations were performed. In total, 477 women who had term, live births had malaria tested at delivery and their birth outcomes assessed, and were included in the study. Peripheral malaria was detected via polymerase chain reaction among 10.9% (n=87) at first prenatal care visit and 8.8% (n=36) at delivery. Insecticide-treated bed nets (ITNs) were used by 73.6% (n=583) and were associated with decreased malaria risk. There was a trend for impaired fetal growth and placental blood flow in malaria-infected women in the second trimester, but not later in pregnancy. Among women with low body mass index (BMI), malaria was associated with reduced birth weight (P=0.04); anthropometric measures were similar otherwise. With IPTp-SP and ITNs, malaria in pregnancy was associated with transient differences in utero, and reduced birth weight was restricted to those with low BMI. Copyright © 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

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

Resistance to malaria through structural variation of red blood cell invasion receptors

PubMed Central

Leffler, Ellen M.; Band, Gavin; Busby, George B.J.; Kivinen, Katja; Le, Quang Si; Clarke, Geraldine M.; Bojang, Kalifa A.; Conway, David J.; Jallow, Muminatou; Sisay-Joof, Fatoumatta; Bougouma, Edith C.; Mangano, Valentina D.; Modiano, David; Sirima, Sodiomon B.; Achidi, Eric; Apinjoh, Tobias O.; Marsh, Kevin; Ndila, Carolyne M.; Peshu, Norbert; Williams, Thomas N.; Drakeley, Chris; Manjurano, Alphaxard; Reyburn, Hugh; Riley, Eleanor; Kachala, David; Molyneux, Malcolm; Nyirongo, Vysaul; Taylor, Terrie; Thornton, Nicole; Tilley, Louise; Grimsley, Shane; Drury, Eleanor; Stalker, Jim; Cornelius, Victoria; Hubbart, Christina; Jeffreys, Anna E.; Rowlands, Kate; Rockett, Kirk A.; Spencer, Chris C.A.; Kwiatkowski, Dominic P.

2017-01-01

The malaria parasite Plasmodium falciparum invades human red blood cells via interactions between host and parasite surface proteins. By analyzing genome sequence data from human populations, including 1269 individuals from sub-Saharan Africa, we identify a diverse array of large copy number variants affecting the host invasion receptor genes GYPA and GYPB. We find that a nearby association with severe malaria is explained by a complex structural rearrangement involving the loss of GYPB and gain of two GYPB-A hybrid genes, which encode a serologically distinct blood group antigen known as Dantu. This variant reduces the risk of severe malaria by 40% and has recently risen in frequency in parts of Kenya, yet it appears to be absent from west Africa. These findings link structural variation of red blood cell invasion receptors with natural resistance to severe malaria. PMID:28522690

Birthweight in Offspring of Mothers with High Prevalence of Helminth and Malaria Infection in Coastal Kenya

PubMed Central

Fairley, Jessica K.; Bisanzio, Donal; King, Charles H.; Kitron, Uriel; Mungai, Peter; Muchiri, Eric; King, Christopher L.; Malhotra, Indu

2013-01-01

Results of studies on the associations of maternal helminth infection and malaria-helminth co-infection on birth outcomes have been mixed. A group of 696 pregnant women from the Kwale district in Kenya were recruited and tested for malaria and helminth infection at delivery. Birthweight was documented for 664 infants. A total of 42.7% of the mothers were infected with Plasmodium falciparum, 30.6% with Schistosoma haematobium, 36.2% with filariasis, 31.5% with hookworm, and 5.9% with Trichuris trichiura; co-infection was present in 46.7%. Low birthweight (LBW) (weight < 2,500 grams) was present in 15.4% of the offspring, and 8.3% had a weight z-score ≤ 2 SD below the World Health Organization mean. Only gravida, age, and locale had a significant association with LBW. The high prevalence of maternal infection coupled with a higher than expected percentage of LBW highlight a need for further investigation of the association of maternal co-infection with LBW. PMID:23166193

Costs of early detection systems for epidemic malaria in highland areas of Kenya and Uganda.

PubMed

Mueller, Dirk H; Abeku, Tarekegn A; Okia, Michael; Rapuoda, Beth; Cox, Jonathan

2009-01-16

Malaria epidemics cause substantial morbidity and mortality in highland areas of Africa. The costs of detecting and controlling these epidemics have not been explored adequately in the past. This study presents the costs of establishing and running an early detection system (EDS) for epidemic malaria in four districts in the highlands of Kenya and Uganda. An economic costing was carried out from the health service provider's perspective in both countries. Staff time for data entry and processing, as well as supervising and coordinating EDS activities at district and national levels was recorded and associated opportunity costs estimated. A threshold analysis was carried out to determine the number of DALYs or deaths that would need to be averted in order for the EDS to be considered cost-effective. The total costs of the EDS per district per year ranged between US$ 14,439 and 15,512. Salaries were identified as major cost-drivers, although their relative contribution to overall costs varied by country. Costs of relaying surveillance data between facilities and district offices (typically by hand) were also substantial. Data from Uganda indicated that 4% or more of overall costs could potentially be saved by switching to data transfer via mobile phones. Based on commonly used thresholds, 96 DALYs in Uganda and 103 DALYs in Kenya would need to be averted annually in each district for the EDS to be considered cost-effective. Results from this analysis suggest that EDS are likely to be cost-effective. Further studies that include the costs and effects of the health systems' reaction prompted by EDS will need to be undertaken in order to obtain comprehensive cost-effectiveness estimates.

The Effect of Indoor Residual Spraying on the Prevalence of Malaria Parasite Infection, Clinical Malaria and Anemia in an Area of Perennial Transmission and Moderate Coverage of Insecticide Treated Nets in Western Kenya

PubMed Central

Gimnig, John E.; Otieno, Peter; Were, Vincent; Marwanga, Doris; Abong’o, Daisy; Wiegand, Ryan; Williamson, John; Wolkon, Adam; Zhou, Ying; Bayoh, M. Nabie; Lobo, Neil F.; Laserson, Kayla; Kariuki, Simon; Hamel, Mary J.

2016-01-01

Background Insecticide treated nets (ITNs) and indoor residual spraying (IRS) have been scaled up for malaria prevention in sub-Saharan Africa. However, there are few studies on the benefit of implementing IRS in areas with moderate to high coverage of ITNs. We evaluated the impact of an IRS program on malaria related outcomes in western Kenya, an area of intense perennial malaria transmission and moderate ITN coverage (55–65% use of any net the previous night). Methods The Kenya Division of Malaria Control, with support from the US President’s Malaria Initiative, conducted IRS in one lowland endemic district with moderate coverage of ITNs. Surveys were conducted in the IRS district and a neighboring district before IRS, after one round of IRS in July-Sept 2008 and after a second round of IRS in April-May 2009. IRS was conducted with pyrethroid insecticides. At each survey, 30 clusters were selected for sampling and within each cluster, 12 compounds were randomly selected. The primary outcomes measured in all residents of selected compounds included malaria parasitemia, clinical malaria (P. falciparum infection plus history of fever) and anemia (Hb<8) of all residents in randomly selected compounds. At each survey round, individuals from the IRS district were matched to those from the non-IRS district using propensity scores and multivariate logistic regression models were constructed based on the matched dataset. Results At baseline and after one round of IRS, there were no differences between the two districts in the prevalence of malaria parasitemia, clinical malaria or anemia. After two rounds of IRS, the prevalence of malaria parasitemia was 6.4% in the IRS district compared to 16.7% in the comparison district (OR = 0.36, 95% CI = 0.22–0.59, p<0.001). The prevalence of clinical malaria was also lower in the IRS district (1.8% vs. 4.9%, OR = 0.37, 95% CI = 0.20–0.68, p = 0.001). The prevalence of anemia was lower in the IRS district but only in children

Motivation and satisfaction among community health workers administering rapid diagnostic tests for malaria in Western Kenya.

PubMed

Winn, Laura K; Lesser, Adriane; Menya, Diana; Baumgartner, Joy N; Kipkoech Kirui, Joseph; Saran, Indrani; Prudhomme-O'Meara, Wendy

2018-06-01

The continued success of community case management (CCM) programs in low-resource settings depends on the ability of these programs to retain the community health workers (CHWs), many of whom are volunteers, and maintain their high-quality performance. This study aims to identify factors related to the motivation and satisfaction of CHWs working in a malaria CCM program in two sub-counties in Western Kenya. We interviewed 70 CHWs who were trained to administer malaria rapid diagnostic tests as part of a broader study evaluating a malaria CCM program. We identified factors related to CHWs' motivation and their satisfaction with participation in the program, as well as the feasibility of program scale-up. We used principal components analysis to develop an overall CHW satisfaction score and assessed associations between this score and individual CHW characteristics as well as their experiences in the program. The majority of CHWs reported that they were motivated to perform their role in this malaria CCM program by a personal desire to help their community (69%). The most common challenge CHWs reported was a lack of community understanding about malaria diagnostic testing and CHWs' role in the program (39%). Most CHWs (89%) reported that their involvement in the diagnostic testing intervention had either a neutral or a net positive effect on their other CHW activities, including improving skills applicable to other tasks. CHWs who said they strongly agreed with the statement that their work with the malaria program was appreciated by the community had a 0.76 standard deviation (SD) increase in their overall satisfaction score (95% confidence interval CI = 0.10-1.24, P  = 0.03). Almost all CHWs (99%) strongly agreed that they wanted to continue their role in the malaria program. Overall, CHWs reported high satisfaction with their role in community-based malaria diagnosis, though they faced challenges primarily related to community understanding and

Motivation and satisfaction among community health workers administering rapid diagnostic tests for malaria in Western Kenya

PubMed Central

Winn, Laura K; Lesser, Adriane; Menya, Diana; Baumgartner, Joy N; Kipkoech Kirui, Joseph; Saran, Indrani; Prudhomme-O’Meara, Wendy

2018-01-01

Background The continued success of community case management (CCM) programs in low-resource settings depends on the ability of these programs to retain the community health workers (CHWs), many of whom are volunteers, and maintain their high-quality performance. This study aims to identify factors related to the motivation and satisfaction of CHWs working in a malaria CCM program in two sub-counties in Western Kenya. Methods We interviewed 70 CHWs who were trained to administer malaria rapid diagnostic tests as part of a broader study evaluating a malaria CCM program. We identified factors related to CHWs’ motivation and their satisfaction with participation in the program, as well as the feasibility of program scale-up. We used principal components analysis to develop an overall CHW satisfaction score and assessed associations between this score and individual CHW characteristics as well as their experiences in the program. Results The majority of CHWs reported that they were motivated to perform their role in this malaria CCM program by a personal desire to help their community (69%). The most common challenge CHWs reported was a lack of community understanding about malaria diagnostic testing and CHWs’ role in the program (39%). Most CHWs (89%) reported that their involvement in the diagnostic testing intervention had either a neutral or a net positive effect on their other CHW activities, including improving skills applicable to other tasks. CHWs who said they strongly agreed with the statement that their work with the malaria program was appreciated by the community had a 0.76 standard deviation (SD) increase in their overall satisfaction score (95% confidence interval CI = 0.10-1.24, P = 0.03). Almost all CHWs (99%) strongly agreed that they wanted to continue their role in the malaria program. Conclusions Overall, CHWs reported high satisfaction with their role in community-based malaria diagnosis, though they faced challenges primarily related

Improving educational achievement and anaemia of school children: design of a cluster randomised trial of school-based malaria prevention and enhanced literacy instruction in Kenya

PubMed Central

2010-01-01

Background Improving the health of school-aged children can yield substantial benefits for cognitive development and educational achievement. However, there is limited experimental evidence on the benefits of school-based malaria prevention or how health interventions interact with other efforts to improve education quality. This study aims to evaluate the impact of school-based malaria prevention and enhanced literacy instruction on the health and educational achievement of school children in Kenya. Design A factorial, cluster randomised trial is being implemented in 101 government primary schools on the coast of Kenya. The interventions are (i) intermittent screening and treatment of malaria in schools by public health workers and (ii) training workshops and support for teachers to promote explicit and systematic literacy instruction. Schools are randomised to one of four groups: receiving either (i) the malaria intervention alone; (ii) the literacy intervention alone; (iii) both interventions combined; or (iv) control group where neither intervention is implemented. Children from classes 1 and 5 are randomly selected and followed up for 24 months. The primary outcomes are educational achievement and anaemia, the hypothesised mediating variables through which education is affected. Secondary outcomes include malaria parasitaemia, school attendance and school performance. A nested process evaluation, using semi-structured interviews, focus group discussion and a stakeholder analysis will investigate the community acceptability, feasibility and cost-effectiveness of the interventions. Discussion Across Africa, governments are committed to improve health and education of school-aged children, but seek clear policy and technical guidance as to the optimal approach to address malaria and improved literacy. This evaluation will be one of the first to simultaneously evaluate the impact of health and education interventions in the improvement of educational achievement

Improving educational achievement and anaemia of school children: design of a cluster randomised trial of school-based malaria prevention and enhanced literacy instruction in Kenya.

PubMed

Brooker, Simon; Okello, George; Njagi, Kiambo; Dubeck, Margaret M; Halliday, Katherine E; Inyega, Hellen; Jukes, Matthew C H

2010-10-07

Improving the health of school-aged children can yield substantial benefits for cognitive development and educational achievement. However, there is limited experimental evidence on the benefits of school-based malaria prevention or how health interventions interact with other efforts to improve education quality. This study aims to evaluate the impact of school-based malaria prevention and enhanced literacy instruction on the health and educational achievement of school children in Kenya. A factorial, cluster randomised trial is being implemented in 101 government primary schools on the coast of Kenya. The interventions are (i) intermittent screening and treatment of malaria in schools by public health workers and (ii) training workshops and support for teachers to promote explicit and systematic literacy instruction. Schools are randomised to one of four groups: receiving either (i) the malaria intervention alone; (ii) the literacy intervention alone; (iii) both interventions combined; or (iv) control group where neither intervention is implemented. Children from classes 1 and 5 are randomly selected and followed up for 24 months. The primary outcomes are educational achievement and anaemia, the hypothesised mediating variables through which education is affected. Secondary outcomes include malaria parasitaemia, school attendance and school performance. A nested process evaluation, using semi-structured interviews, focus group discussion and a stakeholder analysis will investigate the community acceptability, feasibility and cost-effectiveness of the interventions. Across Africa, governments are committed to improve health and education of school-aged children, but seek clear policy and technical guidance as to the optimal approach to address malaria and improved literacy. This evaluation will be one of the first to simultaneously evaluate the impact of health and education interventions in the improvement of educational achievement. Reflection is made on the

Spatially variable risk factors for malaria in a geographically heterogeneous landscape, western Kenya: an explorative study.

PubMed

Homan, Tobias; Maire, Nicolas; Hiscox, Alexandra; Di Pasquale, Aurelio; Kiche, Ibrahim; Onoka, Kelvin; Mweresa, Collins; Mukabana, Wolfgang R; Ross, Amanda; Smith, Thomas A; Takken, Willem

2016-01-04

Large reductions in malaria transmission and mortality have been achieved over the last decade, and this has mainly been attributed to the scale-up of long-lasting insecticidal bed nets and indoor residual spraying with insecticides. Despite these gains considerable residual, spatially heterogeneous, transmission remains. To reduce transmission in these foci, researchers need to consider the local demographical, environmental and social context, and design an appropriate set of interventions. Exploring spatially variable risk factors for malaria can give insight into which human and environmental characteristics play important roles in sustaining malaria transmission. On Rusinga Island, western Kenya, malaria infection was tested by rapid diagnostic tests during two cross-sectional surveys conducted 3 months apart in 3632 individuals from 790 households. For all households demographic data were collected by means of questionnaires. Environmental variables were derived using Quickbird satellite images. Analyses were performed on 81 project clusters constructed by a traveling salesman algorithm, each containing 50-51 households. A standard linear regression model was fitted containing multiple variables to determine how much of the spatial variation in malaria prevalence could be explained by the demographic and environmental data. Subsequently, a geographically-weighted regression (GWR) was performed assuming non-stationarity of risk factors. Special attention was taken to investigate the effect of residual spatial autocorrelation and local multicollinearity. Combining the data from both surveys, overall malaria prevalence was 24%. Scan statistics revealed two clusters which had significantly elevated numbers of malaria cases compared to the background prevalence across the rest of the study area. A multivariable linear model including environmental and household factors revealed that higher socioeconomic status, outdoor occupation and population density were

Glucose-6-phosphate dehydrogenase deficiency and the risk of malaria and other diseases in children in Kenya: a case-control and a cohort study

PubMed Central

Uyoga, Sophie; Ndila, Carolyne M; Macharia, Alex W; Nyutu, Gideon; Shah, Shivang; Peshu, Norbert; Clarke, Geraldine M; Kwiatkowski, Dominic P; Rockett, Kirk A; Williams, Thomas N

2015-01-01

Summary Background The global prevalence of X-linked glucose-6-phosphate dehydrogenase (G6PD) deficiency is thought to be a result of selection by malaria, but epidemiological studies have yielded confusing results. We investigated the relationships between G6PD deficiency and both malaria and non-malarial illnesses among children in Kenya. Methods We did this study in Kilifi County, Kenya, where the G6PD c.202T allele is the only significant cause of G6PD deficiency. We tested the associations between G6PD deficiency and severe and complicated Plasmodium falciparum malaria through a case-control study of 2220 case and 3940 control children. Cases were children aged younger than 14 years, who visited the high dependency ward of Kilifi County Hospital with severe malaria between March 1, 1998, and Feb 28, 2010. Controls were children aged between 3–12 months who were born within the same study area between August 2006, and September 2010. We assessed the association between G6PD deficiency and both uncomplicated malaria and other common diseases of childhood in a cohort study of 752 children aged younger than 10 years. Participants of this study were recruited from a representative sample of households within the Ngerenya and Chonyi areas of Kilifi County between Aug 1, 1998, and July 31, 2001. The primary outcome measure for the case-control study was the odds ratio for hospital admission with severe malaria (computed by logistic regression) while for the cohort study it was the incidence rate ratio for uncomplicated malaria and non-malaria illnesses (computed by Poisson regression), by G6PD deficiency category. Findings 2863 (73%) children in the control group versus 1643 (74%) in the case group had the G6PD normal genotype, 639 (16%) versus 306 (14%) were girls heterozygous for G6PD c.202T, and 438 (11%) versus 271 (12%) children were either homozygous girls or hemizygous boys. Compared with boys and girls without G6PD deficiency, we found significant

Glucose-6-phosphate dehydrogenase deficiency and the risk of malaria and other diseases in children in Kenya: a case-control and a cohort study.

PubMed

Uyoga, Sophie; Ndila, Carolyne M; Macharia, Alex W; Nyutu, Gideon; Shah, Shivang; Peshu, Norbert; Clarke, Geraldine M; Kwiatkowski, Dominic P; Rockett, Kirk A; Williams, Thomas N

2015-10-01

The global prevalence of X-linked glucose-6-phosphate dehydrogenase (G6PD) deficiency is thought to be a result of selection by malaria, but epidemiological studies have yielded confusing results. We investigated the relationships between G6PD deficiency and both malaria and non-malarial illnesses among children in Kenya. We did this study in Kilifi County, Kenya, where the G6PD c.202T allele is the only significant cause of G6PD deficiency. We tested the associations between G6PD deficiency and severe and complicated Plasmodium falciparum malaria through a case-control study of 2220 case and 3940 control children. Cases were children aged younger than 14 years, who visited the high dependency ward of Kilifi County Hospital with severe malaria between March 1, 1998, and Feb 28, 2010. Controls were children aged between 3-12 months who were born within the same study area between August 2006, and September 2010. We assessed the association between G6PD deficiency and both uncomplicated malaria and other common diseases of childhood in a cohort study of 752 children aged younger than 10 years. Participants of this study were recruited from a representative sample of households within the Ngerenya and Chonyi areas of Kilifi County between Aug 1, 1998, and July 31, 2001. The primary outcome measure for the case-control study was the odds ratio for hospital admission with severe malaria (computed by logistic regression) while for the cohort study it was the incidence rate ratio for uncomplicated malaria and non-malaria illnesses (computed by Poisson regression), by G6PD deficiency category. 2863 (73%) children in the control group versus 1643 (74%) in the case group had the G6PD normal genotype, 639 (16%) versus 306 (14%) were girls heterozygous for G6PD c.202T, and 438 (11%) versus 271 (12%) children were either homozygous girls or hemizygous boys. Compared with boys and girls without G6PD deficiency, we found significant protection from severe malaria (odds ratio [OR

Fever treatment in the absence of malaria transmission in an urban informal settlement in Nairobi, Kenya.

PubMed

Ye, Yazoume; Madise, Nyovani; Ndugwa, Robert; Ochola, Sam; Snow, Robert W

2009-07-15

In sub-Saharan Africa, knowledge of malaria transmission across rapidly proliferating urban centres and recommendations for its prevention or management remain poorly defined. This paper presents the results of an investigation into infection prevalence and treatment of recent febrile events among a slum population in Nairobi, Kenya. In July 2008, a community-based malaria parasite prevalence survey was conducted in Korogocho slum, which forms part of the Nairobi Urban Health and Demographic Surveillance system. Interviewers visited 1,069 participants at home and collected data on reported fevers experienced over the preceding 14 days and details on the treatment of these episodes. Each participant was tested for malaria parasite presence with Rapid Diagnostic Test (RDT) and microscopy. Descriptive analyses were performed to assess the period prevalence of reported fever episodes and treatment behaviour. Of the 1,069 participants visited, 983 (92%) consented to be tested. Three were positive for Plasmodium falciparum using RDT; however, all were confirmed negative on microscopy. Microscopic examination of all 953 readable slides showed zero prevalence. Overall, from the 1,004 participants who have data on fever, 170 fever episodes were reported giving a relatively high period prevalence (16.9%, 95% CI:13.9%-20.5%) and higher among children below five years (20.1%, 95%CI:13.8%-27.8%). Of the fever episodes with treatment information 54.3% (95%CI:46.3%-62.2%) were treated as malaria using mainly sulphadoxine-pyrimethamine or amodiaquine, including those managed at a formal health facility. Only four episodes were managed using the nationally recommended first-line treatment, artemether-lumefantrine. The study could not demonstrate any evidence of malaria in Korogocho, a slum in the centre of Nairobi. Fever was a common complaint and often treated as malaria with anti-malarial drugs. Strategies, including testing for malaria parasites to reduce the inappropriate

Local Barriers and Solutions to Improve Care-Seeking for Childhood Pneumonia, Diarrhoea and Malaria in Kenya, Nigeria and Niger: A Qualitative Study

PubMed Central

Bedford, K. Juliet A.; Sharkey, Alyssa B.

2014-01-01

We present qualitative research findings on care-seeking and treatment uptake for pneumonia, diarrhoea and malaria among children under 5 in Kenya, Nigeria and Niger. The study aimed to determine the barriers caregivers face in accessing treatment for these conditions; to identify local solutions that facilitate more timely access to treatment; and to present these findings as a platform from which to develop context-specific strategies to improve care-seeking for childhood illness. Kenya, Nigeria and Niger are three high burden countries with low rates of related treatment coverage, particularly in underserved areas. Data were collected in Homa Bay County in Nyanza Province, Kenya; in Kebbi and Cross River States, Nigeria; and in the Maradi and Tillabéri regions of Niger. Primary caregivers of children under 5 who did not regularly engage with health services or present their child at a health facility during illness episodes were purposively selected for interview. Data underwent rigorous thematic analysis. We organise the identified barriers and related solutions by theme: financial barriers; distance/location of health facilities; socio-cultural barriers and gender dynamics; knowledge and information barriers; and health facility deterrents. The relative importance of each differed by locality. Participant suggested solutions ranged from community-level actions to facility-level and more policy-oriented actions, plus actions to change underlying problems such as social perceptions and practices and gender dynamics. We discuss the feasibility and implications of these suggested solutions. Given the high burden of childhood morbidity and mortality due to pneumonia, diarrhoea and malaria in Kenya, Nigeria and Niger, this study provides important insights relating to demand-side barriers and locally proposed solutions. Significant advancements are possible when communities participate in both problem identification and resolution, and are engaged as important

Evaluation of fluorescent in-situ hybridization technique for diagnosis of malaria in Ahero Sub-County hospital, Kenya.

PubMed

Kandie, Regina; Ochola, Rachel; Njaanake, Kariuki

2018-01-08

Malaria is a major cause of morbidity and mortality. Treatment of malaria in a timely manner could avert deaths. Treatment ultimately relies on the rapid and accurate diagnosis. Fluorescence in situ hybridization (FISH), a cytogenetic technique based on detection of specific nucleic acid, has the potential to address the limitations of the current diagnostic approaches. This study investigates further the performance of FISH for the diagnosis of malaria in a rural setting in Western Kenya. Blood samples from 302 patients presenting with fever (temperature ≥ 37.5 °C) were examined for malaria using the Giemsa microscopy (GM), rapid diagnostic test (RDT), polymerase chain reaction (PCR) and FISH. The sensitivity and specificity of FISH was 85.6% and 96.2% respectively, while the corresponding values for GM were 82.2% and 100% respectively. RDT and PCR had sensitivities of 91.1% and 98.9%, respectively with their specificities being 89.6 and 100%, respectively. The positive predictive values for RDT, GM, FISH and PCR were 78.8%, 100%, 90.6% and 100%, respectively. The negative predictive values for RDT, GM, FISH and PCR were 96.0%, 93.0%, 94.0% and 99.5%, respectively. Their respective diagnostic accuracies were 90.1%, 94.7% 93.0% and 99.7%. The present study demonstrates that the specificity and reproducibility of FISH assays are high, thus adding to the growing evidence on the potential of the technique as an effective tool for the detection of malaria parasites in remote settings.

Resistance to malaria through structural variation of red blood cell invasion receptors.

PubMed

Leffler, Ellen M; Band, Gavin; Busby, George B J; Kivinen, Katja; Le, Quang Si; Clarke, Geraldine M; Bojang, Kalifa A; Conway, David J; Jallow, Muminatou; Sisay-Joof, Fatoumatta; Bougouma, Edith C; Mangano, Valentina D; Modiano, David; Sirima, Sodiomon B; Achidi, Eric; Apinjoh, Tobias O; Marsh, Kevin; Ndila, Carolyne M; Peshu, Norbert; Williams, Thomas N; Drakeley, Chris; Manjurano, Alphaxard; Reyburn, Hugh; Riley, Eleanor; Kachala, David; Molyneux, Malcolm; Nyirongo, Vysaul; Taylor, Terrie; Thornton, Nicole; Tilley, Louise; Grimsley, Shane; Drury, Eleanor; Stalker, Jim; Cornelius, Victoria; Hubbart, Christina; Jeffreys, Anna E; Rowlands, Kate; Rockett, Kirk A; Spencer, Chris C A; Kwiatkowski, Dominic P

2017-06-16

The malaria parasite Plasmodium falciparum invades human red blood cells by a series of interactions between host and parasite surface proteins. By analyzing genome sequence data from human populations, including 1269 individuals from sub-Saharan Africa, we identify a diverse array of large copy-number variants affecting the host invasion receptor genes GYPA and GYPB We find that a nearby association with severe malaria is explained by a complex structural rearrangement involving the loss of GYPB and gain of two GYPB-A hybrid genes, which encode a serologically distinct blood group antigen known as Dantu. This variant reduces the risk of severe malaria by 40% and has recently increased in frequency in parts of Kenya, yet it appears to be absent from west Africa. These findings link structural variation of red blood cell invasion receptors with natural resistance to severe malaria. Copyright © 2017, American Association for the Advancement of Science.

Costs of early detection systems for epidemic malaria in highland areas of Kenya and Uganda

PubMed Central

Mueller, Dirk H; Abeku, Tarekegn A; Okia, Michael; Rapuoda, Beth; Cox, Jonathan

2009-01-01

Background Malaria epidemics cause substantial morbidity and mortality in highland areas of Africa. The costs of detecting and controlling these epidemics have not been explored adequately in the past. This study presents the costs of establishing and running an early detection system (EDS) for epidemic malaria in four districts in the highlands of Kenya and Uganda. Methods An economic costing was carried out from the health service provider's perspective in both countries. Staff time for data entry and processing, as well as supervising and coordinating EDS activities at district and national levels was recorded and associated opportunity costs estimated. A threshold analysis was carried out to determine the number of DALYs or deaths that would need to be averted in order for the EDS to be considered cost-effective. Results The total costs of the EDS per district per year ranged between US$ 14,439 and 15,512. Salaries were identified as major cost-drivers, although their relative contribution to overall costs varied by country. Costs of relaying surveillance data between facilities and district offices (typically by hand) were also substantial. Data from Uganda indicated that 4% or more of overall costs could potentially be saved by switching to data transfer via mobile phones. Based on commonly used thresholds, 96 DALYs in Uganda and 103 DALYs in Kenya would need to be averted annually in each district for the EDS to be considered cost-effective. Conclusion Results from this analysis suggest that EDS are likely to be cost-effective. Further studies that include the costs and effects of the health systems' reaction prompted by EDS will need to be undertaken in order to obtain comprehensive cost-effectiveness estimates. PMID:19149878

Mass mosquito trapping for malaria control in western Kenya: study protocol for a stepped wedge cluster-randomised trial.

PubMed

Hiscox, Alexandra; Homan, Tobias; Mweresa, Collins K; Maire, Nicolas; Di Pasquale, Aurelio; Masiga, Daniel; Oria, Prisca A; Alaii, Jane; Leeuwis, Cees; Mukabana, Wolfgang R; Takken, Willem; Smith, Thomas A

2016-07-26

Increasing levels of insecticide resistance as well as outdoor, residual transmission of malaria threaten the efficacy of existing vector control tools used against malaria mosquitoes. The development of odour-baited mosquito traps has led to the possibility of controlling malaria through mass trapping of malaria vectors. Through daily removal trapping against a background of continued bed net use it is anticipated that vector populations could be suppressed to a level where continued transmission of malaria will no longer be possible. A stepped wedge cluster-randomised trial design was used for the implementation of mass mosquito trapping on Rusinga Island, western Kenya (the SolarMal project). Over the course of 2 years (2013-2015) all households on the island were provided with a solar-powered mosquito trapping system. A continuous health and demographic surveillance system combined with parasitological surveys three times a year, successive rounds of mosquito monitoring and regular sociological studies allowed measurement of intervention outcomes before, during and at completion of the rollout of traps. Data collection continued after achieving mass coverage with traps in order to estimate the longer term effectiveness of this novel intervention. Solar energy was exploited to provide electric light and mobile phone charging for each household, and the impacts of these immediate tangible benefits upon acceptability of and adherence to the use of the intervention are being measured. This study will be the first to evaluate whether the principle of solar-powered mass mosquito trapping could be an effective tool for elimination of malaria. If proven to be effective, this novel approach to malaria control would be a valuable addition to the existing strategies of long-lasting insecticide-treated nets and case management. Sociological studies provide a knowledge base for understanding the usage of this novel tool. Trialregister.nl: NTR3496 - SolarMal. Registered on

Prevalence and associated determinants of malaria parasites among Kenyan children.

PubMed

Sultana, Marufa; Sheikh, Nurnabi; Mahumud, Rashidul Alam; Jahir, Tania; Islam, Ziaul; Sarker, Abdur Razzaque

2017-01-01

Approximately 80% of deaths attributed to malaria worldwide occurred mainly in Africa in 2015. Kenya is one of the major malaria endemic countries, making malaria the leading public health concern in this country. This study intended to document the prevalence of malaria and determine associated factors including socioeconomic status among children aged 6 months to 14 years in Kenya. This study analyzed the secondary data extracted from the 2015 Kenya Malaria Indicator Survey (KMIS), a cross-sectional country representative survey. Associations of demographic, socioeconomic, community-based, and behavioral factors with the prevalence of malaria in children were analyzed using multivariable logistic regression analysis. Data from 7040 children aged 6 months to 14 years were analyzed. The prevalence of malaria showed an upward trend in terms of age, with the highest prevalence among children aged 11-14 years. Prevalence was also higher among rural children (10.16%) compared to urban children (2.93%), as well as poor children (11.05%) compared to rich children (3.23%). The likelihood of having malaria was higher among children aged 10-14 years (AOR = 4.47, 95% CI = 3.33, 6.02; P <  0.001) compared with children aged under 5 years. The presence of anemia (AOR = 3.52, 95% CI = 2.78, 4.45; P  < 0.001), rural residence (AOR = 1.71, 95% CI = 1.31, 2.22; P <  0.001), lack of a hanging mosquito net (AOR = 2.38, 95% CI = 1.78, 3.19; P <  0.001), primary education level of the household head (AOR = 1.15, 95% CI = 1.08, 2.25; P <  0.05), and other factors, such as the household having electricity and access to media such as television or radio, were also associated with the likelihood of infection. This study demonstrated the need to focus on awareness programs to prevent malaria and to use existing knowledge in practice to control the malaria burden in Kenya. Furthermore, this study suggests that improving the information available through

Polymorphisms in the K13 Gene in Plasmodium falciparum from Different Malaria Transmission Areas of Kenya.

PubMed

de Laurent, Zaydah R; Chebon, Lorna J; Ingasia, Luicer A; Akala, Hoseah M; Andagalu, Ben; Ochola-Oyier, Lynette Isabella; Kamau, Edwin

2018-05-01

The development of artemisinin (ART)-resistant parasites in Southeast Asia (SEA) threatens malaria control globally. Mutations in the Kelch 13 (K13)-propeller domain have been useful in identifying ART resistance in SEA. ART combination therapy (ACT) remains highly efficacious in the treatment of uncomplicated malaria in Sub-Saharan Africa (SSA). However, it is crucial that the efficacy of ACT is closely monitored. Toward this effort, this study profiled the prevalence of K13 nonsynonymous mutations in different malaria ecological zones of Kenya and in different time periods, before (pre) and after (post) the introduction of ACT as the first-line treatment of malaria. Nineteen nonsynonymous mutations were present in the pre-ACT samples ( N = 64) compared with 22 in the post-ACT samples ( N = 251). Eight of these mutations were present in both pre- and post-ACT parasites. Interestingly, seven of the shared single-nucleotide polymorphisms were at higher frequencies in the pre-ACT than the post-ACT parasites. The A578S mutation reported in SSA and the V568G mutation reported in SEA were found in both pre- and post-ACT parasites, with their frequencies declining post-ACT. D584Y and R539K mutations were found only in post-ACT parasites; changes in these codons have also been reported in SEA with different amino acids. The N585K mutation described for the first time in this study was present only in post-ACT parasites, and it was the most prevalent mutation at a frequency of 5.2%. This study showed the type, prevalence, and frequency of K13 mutations that varied based on the malaria ecological zones and also between the pre- and post-ACT time periods.

Plasmodium falciparum incidence relative to entomologic inoculation rates at a site proposed for testing malaria vaccines in western Kenya.

PubMed

Beier, J C; Oster, C N; Onyango, F K; Bales, J D; Sherwood, J A; Perkins, P V; Chumo, D K; Koech, D V; Whitmire, R E; Roberts, C R

1994-05-01

Relationships between Plasmodium falciparum incidence and entomologic inoculation rates (EIRs) were determined for a 21-month period in Saradidi, western Kenya, in preparation for malaria vaccine field trials. Children, ranging in age from six months to six years and treated to clear malaria parasites, were monitored daily for up to 12 weeks to detect new malaria infections. Overall, new P. falciparum infections were detected in 77% of 809 children. The percentage of children that developed infections per two-week period averaged 34.7%, ranging from 7.3% to 90.9%. Transmission by vector populations was detected in 86.4% (38 of 44) of the two-week periods, with daily EIRs averaging 0.75 infective bites per person. Periods of intense transmission during April to August, and from November to January, coincided with seasonal rains. Relationships between daily malaria attack rates and EIRs indicated that an average of only 7.5% (1 in 13) of the sporozoite inoculations produced new infections in children. Regression analysis demonstrated that EIRs accounted for 74% of the variation in attack rates. One of the components of the EIR, the human-biting rate, alone accounted for 68% of the variation in attack rates. Thus, measurements of either the EIR or the human-biting rate can be used to predict corresponding attack rates in children. These baseline epidemiologic studies indicate that the intense transmission patterns of P. falciparum in Saradidi will provide excellent conditions for evaluating malaria vaccine efficacy.

Microdam Impoundments Provide Suitable Habitat for Larvae of Malaria Vectors: An Observational Study in Western Kenya.

PubMed

McCann, Robert S; Gimnig, John E; Bayoh, M Nabie; Ombok, Maurice; Walker, Edward D

2018-05-04

Impoundments formed by microdams in rural areas of Africa are important sources of water for people, but they provide potential larval habitats for Anopheles (Diptera: Culicidae) mosquitoes that are vectors of malaria. To study this association, the perimeters of 31 microdam impoundments in western Kenya were sampled for Anopheles larvae in three zones (patches of floating and emergent vegetation, shorelines of open water, and aggregations of cattle hoofprints) across dry and rainy seasons. Of 3,169 larvae collected, most (86.8%) were collected in the rainy season. Of 2,403 larvae successfully reared to fourth instar or adult, nine species were identified; most (80.2%) were Anopheles arabiensis Patton, sampled from hoofprint zones in the rainy season. Other species collected were Anopheles coustani Laveran, Anopheles gambiae s.s. Giles, Anopheles funestus Giles, and Anopheles rivulorum Leeson, Anopheles pharoensis Theobald, Anopheles squamosus Theobald, Anopheles rufipes (Gough), and Anopheles ardensis (Theobald). Larvae of An. funestus were uncommon (1.5%) in both dry and rainy seasons and were confined to vegetated zones, suggesting that microdam impoundments are not primary habitats for this important vector species, although microdams may provide a dry season refuge habitat for malaria vectors, contributing to population persistence through the dry season. In this study, microdam impoundments clearly provided habitat for the malaria vector An. arabiensis in the rainy season, most of which was within the shallow apron side of the impoundments where people brought cattle for watering, resulting in compacted soil with aggregations of water-filled hoofprints. This observation suggests a potential conflict between public health concerns about malaria and people's need for stable and reliable sources of water.

Using mobile phone text messaging for malaria surveillance in rural Kenya

PubMed Central

2014-01-01

Background Effective surveillance systems are required to track malaria testing and treatment practices. A 26-week study “SMS for Life” was piloted in five rural districts of Kenya to examine whether SMS reported surveillance data could ensure real-time visibility of accurate data and their use by district managers to impact on malaria case-management. Methods Health workers from 87 public health facilities used their personal mobile phones to send a weekly structured SMS text message reporting the counts of four basic surveillance data elements to a web-based system accessed by district managers. Longitudinal monitoring of SMS reported data through the web-based system and two rounds of cross-sectional health facility surveys were done to validate accuracy of data. Results Mean response rates were 96% with 87% of facilities reporting on time. Fifty-eight per cent of surveillance data parameters were accurately reported. Overall mean testing rates were 37% with minor weekly variations ranging from 32 to 45%. Overall test positivity rate was 24% (weekly range: 17-37%). Ratio of anti-malarial treatments to test positive cases was 1.7:1 (weekly range: 1.3:1–2.2:1). District specific trends showed fluctuating patterns in testing rates without notable improvement over time but the ratio of anti-malarial treatments to test positive cases improved over short periods of time in three out of five districts. Conclusions The study demonstrated the feasibility of using simple mobile phone text messages to transmit timely surveillance data from peripheral health facilities to higher levels. However, accuracy of data reported was suboptimal. Future work should focus on improving quality of SMS reported surveillance data. PMID:24642130

A geographic information system applied to a malaria field study in western Kenya.

PubMed

Hightower, A W; Ombok, M; Otieno, R; Odhiambo, R; Oloo, A J; Lal, A A; Nahlen, B L; Hawley, W A

1998-03-01

This paper describes use of the global positioning system (GPS) in differential mode (DGPS) to obtain highly accurate longitudes, latitudes, and altitudes of 1,169 houses, 15 schools, 40 churches, four health care centers, 48 major mosquito breeding sites, 10 borehole wells, seven shopping areas, major roads, streams, the shore of Lake Victoria, and other geographic features of interest associated with a longitudinal study of malaria in 15 villages in western Kenya. The area mapped encompassed approximately 70 km2 and included 42.0 km of roads, 54.3 km of streams, and 15.0 km of lake shore. Location data were entered into a geographic information system for map production and linkage with various databases for spatial analyses. Spatial analyses using parasitologic and entomologic data are presented as examples. Background information on DGPS is presented along with estimates of effort and expense to produce the map information.

Marked Decline in Malaria Prevalence among Pregnant Women and Their Offspring from 1996 to 2010 on the South Kenyan Coast

PubMed Central

Kalayjian, Benjamin C.; Malhotra, Indu; Mungai, Peter; Holding, Penny; King, Christopher L.

2013-01-01

Expanded malaria control in Kenya since the early 2000s has resulted in marked reduction in hospital admissions for malaria; however, no studies have reported changes in malaria infection rates in the same population over this period. Randomly selected archived blood samples from four cohorts of pregnant women and their children from 1996 to 2010 in Kwale District, Coast Province, Kenya, were examined for Plasmodium falciparum (Pf), P. malariae, P. ovale, and Plasmodium vivax by quantitative polymerase chain reaction (PCR) and microscopy. Maternal delivery Pf prevalence by PCR declined from 40% in 2000–2005 to 1% in 2009–2010, concordant with increased bed net and malaria chemoprophylaxis use. Individual risk of Pf infection in children from birth to 3 years in serial longitudinal cohort studies declined from almost 100% in 1996–1999 to 15% in 2006–2010. Declines in P. malariae and P. ovale infections rates were also observed. These results show a profound reduction in malaria transmission in coastal Kenya. PMID:24080635

Knowledge and Adherence to the National Guidelines for Malaria Diagnosis in Pregnancy among Health-Care Providers and Drug-Outlet Dispensers in Rural Western Kenya.

PubMed

Riley, Christina; Dellicour, Stephanie; Ouma, Peter; Kioko, Urbanus; Omar, Ahmeddin; Kariuki, Simon; Ng'ang'a, Zipporah; Desai, Meghna; Buff, Ann M; Gutman, Julie R

2018-05-01

Prompt diagnosis and effective treatment of acute malaria in pregnancy (MiP) is important for the mother and fetus; data on health-care provider adherence to diagnostic guidelines in pregnancy are limited. From September to November 2013, a cross-sectional survey was conducted in 51 health facilities and 39 drug outlets in Western Kenya. Provider knowledge of national diagnostic guidelines for uncomplicated MiP were assessed using standardized questionnaires. The use of parasitologic testing was assessed in health facilities via exit interviews with febrile women of childbearing age and in drug outlets via simulated-client scenarios, posing as pregnant women or their spouses. Overall, 93% of providers tested for malaria or accurately described signs and symptoms consistent with clinical malaria. Malaria was parasitologically confirmed in 77% of all patients presenting with febrile illness at health facilities and 5% of simulated clients at drug outlets. Parasitological testing was available in 80% of health facilities; 92% of patients evaluated at these facilities were tested. Only 23% of drug outlets had malaria rapid diagnostic tests (RDTs); at these outlets, RDTs were offered in 17% of client simulations. No differences were observed in testing rates by pregnancy trimester. The study highlights gaps among health providers in diagnostic knowledge and practice related to MiP, and the lack of malaria diagnostic capacity, particularly in drug outlets. The most important factor associated with malaria testing of pregnant women was the availability of diagnostics at the point of service. Interventions that increase the availability of malaria diagnostic services might improve malaria case management in pregnant women.

"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

Quantifying the impact of human mobility on malaria

PubMed Central

Wesolowski, Amy; Eagle, Nathan; Tatem, Andrew J.; Smith, David L.; Noor, Abdisalan M.; Snow, Robert W.; Buckee, Caroline O.

2013-01-01

Human movements contribute to the transmission of malaria on spatial scales that exceed the limits of mosquito dispersal. Identifying the sources and sinks of imported infections due to human travel and locating high-risk sites of parasite importation could greatly improve malaria control programs. Here we use spatially explicit mobile phone data and malaria prevalence information from Kenya to identify the dynamics of human carriers that drive parasite importation between regions. Our analysis identifies specific importation routes that contribute to malaria epidemiology on regional spatial scales. PMID:23066082

Integrated HIV testing, malaria, and diarrhea prevention campaign in Kenya: modeled health impact and cost-effectiveness.

PubMed

Kahn, James G; Muraguri, Nicholas; Harris, Brian; Lugada, Eric; Clasen, Thomas; Grabowsky, Mark; Mermin, Jonathan; Shariff, Shahnaaz

2012-01-01

Efficiently delivered interventions to reduce HIV, malaria, and diarrhea are essential to accelerating global health efforts. A 2008 community integrated prevention campaign in Western Province, Kenya, reached 47,000 individuals over 7 days, providing HIV testing and counseling, water filters, insecticide-treated bed nets, condoms, and for HIV-infected individuals cotrimoxazole prophylaxis and referral for ongoing care. We modeled the potential cost-effectiveness of a scaled-up integrated prevention campaign. We estimated averted deaths and disability-adjusted life years (DALYs) based on published data on baseline mortality and morbidity and on the protective effect of interventions, including antiretroviral therapy. We incorporate a previously estimated scaled-up campaign cost. We used published costs of medical care to estimate savings from averted illness (for all three diseases) and the added costs of initiating treatment earlier in the course of HIV disease. Per 1000 participants, projected reductions in cases of diarrhea, malaria, and HIV infection avert an estimated 16.3 deaths, 359 DALYs and $85,113 in medical care costs. Earlier care for HIV-infected persons adds an estimated 82 DALYs averted (to a total of 442), at a cost of $37,097 (reducing total averted costs to $48,015). Accounting for the estimated campaign cost of $32,000, the campaign saves an estimated $16,015 per 1000 participants. In multivariate sensitivity analyses, 83% of simulations result in net savings, and 93% in a cost per DALY averted of less than $20. A mass, rapidly implemented campaign for HIV testing, safe water, and malaria control appears economically attractive.

Malaria in Kakuma refugee camp, Turkana, Kenya: facilitation of Anopheles arabiensis vector populations by installed water distribution and catchment systems

PubMed Central

2011-01-01

Background Malaria is a major health concern for displaced persons occupying refugee camps in sub-Saharan Africa, yet there is little information on the incidence of infection and nature of transmission in these settings. Kakuma Refugee Camp, located in a dry area of north-western Kenya, has hosted ca. 60,000 to 90,000 refugees since 1992, primarily from Sudan and Somalia. The purpose of this study was to investigate malaria prevalence and attack rate and sources of Anopheles vectors in Kakuma refugee camp, in 2005-2006, after a malaria epidemic was observed by staff at camp clinics. Methods Malaria prevalence and attack rate was estimated from cases of fever presenting to camp clinics and the hospital in August 2005, using rapid diagnostic tests and microscopy of blood smears. Larval habitats of vectors were sampled and mapped. Houses were sampled for adult vectors using the pyrethrum knockdown spray method, and mapped. Vectors were identified to species level and their infection with Plasmodium falciparum determined. Results Prevalence of febrile illness with P. falciparum was highest among the 5 to 17 year olds (62.4%) while malaria attack rate was highest among the two to 4 year olds (5.2/1,000/day). Infected individuals were spatially concentrated in three of the 11 residential zones of the camp. The indoor densities of Anopheles arabiensis, the sole malaria vector, were similar during the wet and dry seasons, but were distributed in an aggregated fashion and predominantly in the same zones where malaria attack rates were high. Larval habitats and larval populations were also concentrated in these zones. Larval habitats were man-made pits of water associated with tap-stands installed as the water delivery system to residents with year round availability in the camp. Three percent of A. arabiensis adult females were infected with P. falciparum sporozoites in the rainy season. Conclusions Malaria in Kakuma refugee camp was due mainly to infection with P

Cost of Community Integrated Prevention Campaign for Malaria, HIV, and Diarrhea in Rural Kenya

PubMed Central

2011-01-01

Background Delivery of community-based prevention services for HIV, malaria, and diarrhea is a major priority and challenge in rural Africa. Integrated delivery campaigns may offer a mechanism to achieve high coverage and efficiency. Methods We quantified the resources and costs to implement a large-scale integrated prevention campaign in Lurambi Division, Western Province, Kenya that reached 47,133 individuals (and 83% of eligible adults) in 7 days. The campaign provided HIV testing, condoms, and prevention education materials; a long-lasting insecticide-treated bed net; and a water filter. Data were obtained primarily from logistical and expenditure data maintained by implementing partners. We estimated the projected cost of a Scaled-Up Replication (SUR), assuming reliance on local managers, potential efficiencies of scale, and other adjustments. Results The cost per person served was $41.66 for the initial campaign and was projected at $31.98 for the SUR. The SUR cost included 67% for commodities (mainly water filters and bed nets) and 20% for personnel. The SUR projected unit cost per person served, by disease, was $6.27 for malaria (nets and training), $15.80 for diarrhea (filters and training), and $9.91 for HIV (test kits, counseling, condoms, and CD4 testing at each site). Conclusions A large-scale, rapidly implemented, integrated health campaign provided services to 80% of a rural Kenyan population with relatively low cost. Scaling up this design may provide similar services to larger populations at lower cost per person. PMID:22189090

What has driven the decline of infant mortality in Kenya in the 2000s?

PubMed

Demombynes, Gabriel; Trommlerová, Sofia Karina

2016-05-01

Substantial declines in early childhood mortality have taken place in many countries in Sub-Saharan Africa. Kenya's infant mortality rate fell by 7.6 percent per year between 2003 and 2008, the fastest rate of decline among the 20 countries in the region for which recent Demographic and Health Survey (DHS) data are available. The average rate of decline across all 20 countries was 3.6 percent per year. Among the possible causes of the observed decline in Kenya is a large-scale campaign to distribute insecticide-treated bednets (ITN) which started in 2004. A Oaxaca-Blinder decomposition using DHS data shows that the increased ownership of bednets in endemic malaria zones explains 79 percent of the decline in infant mortality. Although the Oaxaca-Blinder method cannot identify causal effects, given the wide evidence basis showing that ITN usage can reduce malaria prevalence and the huge surge in ITN ownership in Kenya, it is likely that the decomposition results reflect at least in part a causal effect. The widespread ownership of ITNs in areas of Kenya where malaria is rare suggests that better targeting of ITN provision could improve the cost-effectiveness of such programs. Copyright © 2016. Published by Elsevier B.V.

Delivering new malaria drugs through grassroots private sector.

PubMed

Chiguzo, A N; Mugo, R W; Wacira, D G; Mwenda, J M; Njuguna, E W

2008-09-01

To demonstrate that micro-franchising system is an effective way of improving access to effective health care such as the introduction of first line antimalarias in populations living in underserved rural areas in Kenya. A descriptive study. Child and family wellness (CFW) micro-franchised nurse run clinics in Kenya. In 2007, 39.3% of RDTs carried out were positive for malaria. All malaria positive (RDTs and microscopy) patients received artemether lumefantrine (AL) according to their weight in accordance with the Government approved treatment guidelines. During the same period a total of 3,248 community members were reached with malaria information, however, community expectations took longer to change as patients demanded AL even when the malaria diagnosis was negative. Initially, this led to the dispensing of other antimalarials to patients with malaria like symptoms even with a negative test. This demand decreased with more community education on the importance of the tests. Engaging the private sector though with challenges proved feasible and appropriate in accessing malaria treatment based on clinical diagnosis supported by RDTs to confirm the diagnosis instead of presumptive treatment based on fever. This led to a reduction of antimalarial prescriptions by more than 50%, implying better patient care, rational drug use as well as cost savings on malaria treatment. A micro-franchising system is an effective and sustainable way of improving access to effective health care by populations living in underserved rural areas of Africa. With appropriate supportive training and supervision, the system can adapt to changes in treatment guidelines and to new regimens.

Modeling malaria and typhoid fever co-infection dynamics.

PubMed

Mutua, Jones M; Wang, Feng-Bin; Vaidya, Naveen K

2015-06-01

Malaria and typhoid are among the most endemic diseases, and thus, of major public health concerns in tropical developing countries. In addition to true co-infection of malaria and typhoid, false diagnoses due to similar signs and symptoms and false positive results in testing methods, leading to improper controls, are the major challenges on managing these diseases. In this study, we develop novel mathematical models describing the co-infection dynamics of malaria and typhoid. Through mathematical analyses of our models, we identify distinct features of typhoid and malaria infection dynamics as well as relationships associated to their co-infection. The global dynamics of typhoid can be determined by a single threshold (the typhoid basic reproduction number, R0(T)) while two thresholds (the malaria basic reproduction number, R0(M), and the extinction index, R0(MM)) are needed to determine the global dynamics of malaria. We demonstrate that by using efficient simultaneous prevention programs, the co-infection basic reproduction number, R0, can be brought down to below one, thereby eradicating the diseases. Using our model, we present illustrative numerical results with a case study in the Eastern Province of Kenya to quantify the possible false diagnosis resulting from this co-infection. In Kenya, despite having higher prevalence of typhoid, malaria is more problematic in terms of new infections and disease deaths. We find that false diagnosis-with higher possible cases for typhoid than malaria-cause significant devastating impacts on Kenyan societies. Our results demonstrate that both diseases need to be simultaneously managed for successful control of co-epidemics. Copyright © 2015 Elsevier Inc. All rights reserved.

Fear of being tested for HIV at ANC clinics associated with low uptake of intermittent preventive treatment (IPT) of malaria among pregnant women attending Bondo District Hospital, Western Kenya.

PubMed

Sande, John Hafu; Kaseje, Dan; Nyapada, Linet; Owino, Victor O

2010-03-01

Malaria is a major cause of morbidity and mortality in tropical and subtropical regions, affecting mostly the impoverished sections of the population. Pregnant women living in malaria-endemic areas are at higher risk of malaria infection with higher density of parasitaemia than non-pregnant women. The aim of this study was to assess factors affecting the uptake of IPT among women attending antenatal clinics at Bondo District Hospital, Western Kenya. This study was a hospital-based cross-sectional survey among pregnant women attending clinics. Malaria is endemic in Bondo district. Both women from Bondo town (urban) and greater Bondo District (rural) who had been pregnant for at least 35 weeks or had delivered not more than 6 weeks prior to the survey), and had ANC cards were included in the study. The main outcomes were ANC attendance, IPT doses received and client and provider factors. Results showed that women's knowledge on ANC and IPT was high. The uptake of IPT was low among pregnant women with those from urban areas more likely to make more ANC visits and to get more IPT doses than women from the rural areas. ANC attendance was hampered by the fear of being tested for HIV at the clinic. Perceived side effects associated with IPT-SP hindered IPT uptake and were linked to HIV-related symptoms. Negative attitude among health workers towards pregnant women also adversely impacted IPT uptake. Women suggested that IPT drugs be distributed through community health workers instead of the health facility for improved uptake. Retraining of health workers on the administration of IPT, harmonization of health messages, and assessment of alternative community-based IPT distribution channels ought to be urgently considered. More evidence on the influence of HIV pandemic on perceptions and attitudes toward and uptake of other health interventions is urgently needed.

Translating the Immunogenicity of Prime-boost Immunization With ChAd63 and MVA ME-TRAP From Malaria Naive to Malaria-endemic Populations

PubMed Central

Kimani, Domtila; Jagne, Ya Jankey; Cox, Momodou; Kimani, Eva; Bliss, Carly M; Gitau, Evelyn; Ogwang, Caroline; Afolabi, Muhammed O; Bowyer, Georgina; Collins, Katharine A; Edwards, Nick; Hodgson, Susanne H; Duncan, Christopher J A; Spencer, Alexandra J; Knight, Miguel G; Drammeh, Abdoulie; Anagnostou, Nicholas A; Berrie, Eleanor; Moyle, Sarah; Gilbert, Sarah C; Soipei, Peninah; Okebe, Joseph; Colloca, Stefano; Cortese, Riccardo; Viebig, Nicola K; Roberts, Rachel; Lawrie, Alison M; Nicosia, Alfredo; Imoukhuede, Egeruan B; Bejon, Philip; Chilengi, Roma; Bojang, Kalifa; Flanagan, Katie L; Hill, Adrian V S; Urban, Britta C; Ewer, Katie J

2014-01-01

To induce a deployable level of efficacy, a successful malaria vaccine would likely benefit from both potent cellular and humoral immunity. These requirements are met by a heterologous prime-boost immunization strategy employing a chimpanzee adenovirus vector followed by modified vaccinia Ankara (MVA), both encoding the pre-erythrocytic malaria antigen ME-thrombospondin-related adhesive protein (TRAP), with high immunogenicity and significant efficacy in UK adults. We undertook two phase 1b open-label studies in adults in Kenya and The Gambia in areas of similar seasonal malaria transmission dynamics and have previously reported safety and basic immunogenicity data. We now report flow cytometry and additional interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) data characterizing pre-existing and induced cellular immunity as well as anti-TRAP IgG responses. T-cell responses induced by vaccination averaged 1,254 spot-forming cells (SFC) per million peripheral blood mononuclear cells (PBMC) across both trials and flow cytometry revealed cytokine production from both CD4+ and CD8+ T cells with the frequency of CD8+ IFN-γ-secreting monofunctional T cells (previously shown to associate with vaccine efficacy) particularly high in Kenyan adults. Immunization with ChAd63 and MVA ME-TRAP induced strong cellular and humoral immune responses in adults living in two malaria-endemic regions of Africa. This prime-boost approach targeting the pre-erythrocytic stage of the malaria life-cycle is now being assessed for efficacy in a target population. PMID:24930599

Prevalence of malaria parasites in adults and its determinants in malaria endemic area of Kisumu County, Kenya.

PubMed

Jenkins, Rachel; Omollo, Raymond; Ongecha, Michael; Sifuna, Peter; Othieno, Caleb; Ongeri, Linnet; Kingora, James; Ogutu, Bernhards

2015-07-08

The prevalence of malaria parasites in adults in Africa is less well researched than in children. Therefore, a demographic surveillance site was used to conduct a household survey of adults in the malaria endemic area of Maseno division in Kisumu County near Lake Victoria. A random survey of 1,190 adults living in a demographic health surveillance site in a malaria endemic area of 70,805 population size was conducted, measuring presence of malaria parasites by slide microscopy. Data were analysed using STATA to calculate the prevalence of malaria and associated risk factors. The adult prevalence of presence of malaria parasites in Maseno was 28% (95% CI: 25.4-31.0%). Gender was a significant sociodemographic risk factor in both univariate (OR 1.5, p = 0.005) and multivariate (OR 1.4, p = 0.019) analyses. Females were 50% more likely to have malaria than men. Presence of malaria parasites is common in the adult population of this endemic area, and the rate is greatly increased in women. The presence of such an adult pool of malaria parasites represents a key reservoir factor in transmission of parasites to children, and is relevant for plans to eradicate malaria.

The geography of malaria genetics in the Democratic Republic of Congo: A complex and fragmented landscape

PubMed Central

Carrel, Margaret; Patel, Jaymin; Taylor, Steve M.; Janko, Mark; Mwandagalirwa, Melchior Kashamuka; Tshefu, Antoinette K.; Escalante, Ananias A.; McCollum, Andrea; Alam, Md Tauqeer; Udhayakumar, Venkatachalam; Meshnick, Steven; Emch, Michael

2014-01-01

Understanding how malaria parasites move between populations is important, particularly given the potential for malaria to be reintroduced into areas where it was previously eliminated. We examine the distribution of malaria genetics across seven sites within the Democratic Republic of Congo (DRC) and two nearby countries, Ghana and Kenya, in order to understand how the relatedness of malaria parasites varies across space, and whether there are barriers to the flow of malaria parasites within the DRC or across borders. Parasite DNA was retrieved from dried blood spots from 7 Demographic and Health Survey sample clusters in the DRC. Malaria genetic characteristics of parasites from Ghana and Kenya were also obtained. For each of 9 geographic sites (7 DRC, 1 Ghana and 1 Kenya), a pair-wise RST statistic was calculated, indicating the genetic distance between malaria parasites found in those locations. Mapping genetics across the spatial extent of the study area indicates a complex genetic landscape, where relatedness between two proximal sites may be relatively high (RST > 0.64) or low (RST < 0.05), and where distal sites also exhibit both high and low genetic similarity. Mantel’s tests suggest that malaria genetics differ as geographic distances increase. Principal Coordinate Analysis suggests that genetically related samples are not co-located. Barrier analysis reveals no significant barriers to gene flow between locations. Malaria genetics in the DRC have a complex and fragmented landscape. Limited exchange of genes across space is reflected in greater genetic distance between malaria parasites isolated at greater geographic distances. There is, however, evidence for close genetic ties between distally located sample locations, indicating that movement of malaria parasites and flow of genes is being driven by factors other than distance decay. This research demonstrates the contributions that spatial disease ecology and landscape genetics can make to

Large-scale implementation of disease control programmes: a cost-effectiveness analysis of long-lasting insecticide-treated bed net distribution channels in a malaria-endemic area of western Kenya-a study protocol.

PubMed

Gama, Elvis; Were, Vincent; Ouma, Peter; Desai, Meghna; Niessen, Louis; Buff, Ann M; Kariuki, Simon

2016-11-21

Historically, Kenya has used various distribution models for long-lasting insecticide-treated bed nets (LLINs) with variable results in population coverage. The models presently vary widely in scale, target population and strategy. There is limited information to determine the best combination of distribution models, which will lead to sustained high coverage and are operationally efficient and cost-effective. Standardised cost information is needed in combination with programme effectiveness estimates to judge the efficiency of LLIN distribution models and options for improvement in implementing malaria control programmes. The study aims to address the information gap, estimating distribution cost and the effectiveness of different LLIN distribution models, and comparing them in an economic evaluation. Evaluation of cost and coverage will be determined for 5 different distribution models in Busia County, an area of perennial malaria transmission in western Kenya. Cost data will be collected retrospectively from health facilities, the Ministry of Health, donors and distributors. Programme-effectiveness data, defined as the number of people with access to an LLIN per 1000 population, will be collected through triangulation of data from a nationally representative, cross-sectional malaria survey, a cross-sectional survey administered to a subsample of beneficiaries in Busia County and LLIN distributors' records. Descriptive statistics and regression analysis will be used for the evaluation. A cost-effectiveness analysis will be performed from a health-systems perspective, and cost-effectiveness ratios will be calculated using bootstrapping techniques. The study has been evaluated and approved by Kenya Medical Research Institute, Scientific and Ethical Review Unit (SERU number 2997). All participants will provide written informed consent. The findings of this economic evaluation will be disseminated through peer-reviewed publications. Published by the BMJ Publishing

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.

Medicinal plants used for management of malaria among the Luhya community of Kakamega East sub-County, Kenya.

PubMed

Mukungu, Nillian; Abuga, Kennedy; Okalebo, Faith; Ingwela, Raphael; Mwangi, Julius

2016-12-24

Malaria remains a major health problem worldwide especially in sub-Saharan Africa. In Kenya, 80% of the population is at risk of contracting the disease. Pregnant mothers and children under five years are the most affected by this disease. Antimalarial drug resistance poses a major threat in the fight against malaria necessitating continuous search for new antimalarial drugs. Due to inadequate and inaccessible health facilities, majority of people living in rural communities heavily depend on traditional medicine which involves the use of medicinal plants for the management of malaria. Most of these indigenous knowledge is undocumented and risks being lost yet such information could be useful in the search of new antimalarial agents. An ethnobotanical survey was carried out among the Luhya community of Kakamega East sub-County, a malaria epidemic region, with the aim of documenting the plants used in the management of malaria. Semi-structured questionnaires were used to collect information from 21 informants who included traditional medicine practitioners and other caregivers who had experience in use of plants in management of malaria. These were drawn from 4 villages located in Kakamega East sub-county, within Kakamega County based on their differences in topography. Information recorded included plant names, parts used, mode of preparation and administration and the sources of plant materials. A literature search was conducted using PubMed and google scholar to identify the reported traditional uses of these plants and studied antiplasmodial activities. In this study, 57% of the informants were aged above 50 years and a total of 61% had either no formal education or had only attained primary school education. A total of 42 plant species belonging to 24 families were identified. Most plants used in the management of malaria in this community belonged to Lamiaceae (18%), Leguminosae (9%) and Compositae (9%) plant families. Plants mostly used included Melia

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

Effect of Deforestation and Land Use Changes on Mosquito Productivity and Development in Western Kenya Highlands: Implication for Malaria Risk.

PubMed

Kweka, Eliningaya J; Kimaro, Epiphania E; Munga, Stephen

2016-01-01

African highlands were known to be free of malaria for the past 50 years. However, the ever growing human population in the highlands of Africa has led to the deforestation and land coverage changes to create space for more land for cultivation, grazing, and house construction materials needs. This has lead to the creation of suitable breeding habitats, which are in open places. Decrease of canopy and forest cover has led to increased temperature both in outdoors and indoors in deforested areas. This increased temperature has resulted in the shortening of developmental stages of aquatic stages of mosquitoes and sporogony development in adult mosquitoes. Assessment of the effects of deforestation and land coverage changes (decrease), which leads to temperature changes and subsequently increases survivorship of adults and sporogony development in adult mosquitoes' body was gathered from previous data collected from 2003 to 2012 using different analysis techniques. Habitats productivity, species dynamics and abundance, mosquitoes feeding rates, and sporogony development are presented in relation to temperature changes. The effects of temperature rise due to land cover changes in highlands of western Kenya on larval developmental rates, adult sporogony developments, and malaria risk in human population were derived. Vector species dynamics and abundance in relation to land use changes have been found to change with time. This study found that, land cover changes is a key driver for the temperature rise in African highlands and increases the rate of malaria vectors Anopheles gambiae ssp., An. Funestus , and An. arabiensis colonizing the highlands. It has also significantly enhanced sporogony development rate and adult vector survival and therefore the risk of malaria transmission in the highlands.

Evaluation of Polyethylene-Based Long Lasting Treated Bed Net Netprotect on Anopheles Mosquitoes, Malaria Incidence, and Net Longivity in Western Kenya

PubMed Central

Odhiambo, M. T. O.; Skovmand, O.; Vulule, J. M.; Kokwaro, E. D.

2013-01-01

We studied the effect on malaria incidence, mosquito abundance, net efficacy, net use rate, chemical analysis, and holes of a long lasting insecticide treated bed net (Netprotect) in western Kenya, 2007–2010. Nets were hung in 150 households 6 months before they were hung in a second, 2 km away. Indoor resting densities were monitored by pyrethrum spray catch and malaria cases by passive detection using clinical manifestations and rapid diagnostic test. The probability of finding An. arabiensis in the control area was 2.6 times higher than that in intervention area during the first 6 months. Human blood feeding index of Anopheles funestus declined 17%. After bed nets were hung in the second area, malaria incidence declined 25% down to the level in the first area. Incidence remained at this low level for 2 years. 90% of collected nets were efficacious after 3-year use. Deltamethrin dosage declined from 1.9 to 0.5 g/kg over 3 years. Attrition rate after 3 years was 21%. WHO hole index changed from 333 to 114 to 381 over the three years. This index summarizes the numbers of holes in size categories and multiplies with the mean hole area per category. It is very sensitive to the impact of big holes in a few nets. PMID:24194770

Hidden reservoir of resistant parasites: the missing link in the elimination of falciparum malaria.

PubMed

Abdul-Ghani, Rashad; Mahdy, Mohammed A K; Beier, John C; Basco, Leonardo K

2017-02-06

To successfully eliminate malaria, an integrated system that includes a number of approaches and interventions-aimed at overcoming the threat of antimalarial drug resistance-is required. Significant progress has been made in reducing malaria incidence through large-scale use of artemisinin-based combination therapies and insecticide-treated nets. To consolidate these gains, attention should be paid to the missing links in the elimination of malaria. One of these gaps is the residual reservoir of submicroscopic resistant parasites, which remains after case management or other control measures have been carried out. Therefore, the present opinion piece highlights the importance of exploring the role that submicroscopic resistant parasites could play in hindering malaria elimination by allowing the persistence of transmission, particularly in areas of low transmission or in the pre-elimination and/or elimination phase. If malaria elimination interventions are to be effective, the relative role of the hidden reservoir of resistant parasites needs to be assessed, particularly in regions that are low-transmission settings and/or in pre-elimination and/or elimination phases. Various ongoing studies are focusing on the role of submicroscopic malaria infections in malaria transmission but overlook the possible build-up of resistance to antimalarial drugs among submicroscopic parasite populations. This is an important factor as it may eventually limit the effectiveness of malaria elimination strategies. An evidence-based estimation of the "true" reservoir of resistant parasites can help target the existing and emerging foci of resistant parasites before they spread. Emergence and spread of artemisinin-resistant Plasmodium falciparum malaria in Southeast Asia underline the need to contain drug resistance.

Comparing ownership and use of bed nets at two sites with differential malaria transmission in western Kenya.

PubMed

Ernst, Kacey C; Hayden, Mary H; Olsen, Heather; Cavanaugh, Jamie L; Ruberto, Irene; Agawo, Maurice; Munga, Stephen

2016-04-14

Challenges persist in ensuring access to and optimal use of long-lasting, insecticidal bed nets (LLINs). Factors associated with ownership and use may differ depending on the history of malaria and prevention control efforts in a specific region. Understanding how the cultural and social-environmental context of bed net use may differ between high- and low-risk regions is important when identifying solutions to improve uptake and appropriate use. Community forums and a household, cross-sectional survey were used to collect information on factors related to bed net ownership and use in western Kenya. Sites with disparate levels of transmission were selected, including an endemic lowland area, Miwani, and a highland epidemic-prone area, Kapkangani. Analysis of ownership was stratified by site. A combined site analysis was conducted to examine factors associated with use of all available bed nets. Logistic regression modelling was used to determine factors associated with ownership and use of owned bed nets. Access to bed nets as the leading barrier to their use was identified in community forums and cross-sectional surveys. While disuse of available bed nets was discussed in the forums, it was a relatively rare occurrence in both sites. Factors associated with ownership varied by site. Education, perceived risk of malaria and knowledge of individuals who had died of malaria were associated with higher bed net ownership in the highlands, while in the lowlands individuals reporting it was easy to get a bed net were more likely to own one. A combined site analysis indicated that not using an available bed net was associated with the attitudes that taking malaria drugs is easier than using a bed net and that use of a bed net will not prevent malaria. In addition, individuals with an unused bed net in the household were more likely to indicate that bed nets are difficult to use, that purchased bed nets are better than freely distributed ones, and that bed nets should only

X-linked G6PD deficiency protects hemizygous males but not heterozygous females against severe malaria.

PubMed

Guindo, Aldiouma; Fairhurst, Rick M; Doumbo, Ogobara K; Wellems, Thomas E; Diallo, Dapa A

2007-03-01

Glucose-6-phosphate dehydrogenase (G6PD) is important in the control of oxidant stress in erythrocytes, the host cells for Plasmodium falciparum. Mutations in this enzyme produce X-linked deficiency states associated with protection against malaria, notably in Africa where the A- form of G6PD deficiency is widespread. Some reports have proposed that heterozygous females with mosaic populations of normal and deficient erythrocytes (due to random X chromosome inactivation) have malaria resistance similar to or greater than hemizygous males with populations of uniformly deficient erythrocytes. These proposals are paradoxical, and they are not consistent with currently hypothesized mechanisms of protection. We conducted large case-control studies of the A- form of G6PD deficiency in cases of severe or uncomplicated malaria among two ethnic populations of rural Mali, West Africa, where malaria is hyperendemic. Our results indicate that the uniform state of G6PD deficiency in hemizygous male children conferred significant protection against severe, life-threatening malaria, and that it may have likewise protected homozygous female children. No such protection was evident from the mosaic state of G6PD deficiency in heterozygous females. We also found no significant differences in the parasite densities of males and females with differences in G6PD status. Pooled odds ratios from meta-analysis of our data and data from a previous study confirmed highly significant protection against severe malaria in hemizygous males but not in heterozygous females. Among the different forms of severe malaria, protection was principally evident against cerebral malaria, the most frequent form of life-threatening malaria in these studies. The A- form of G6PD deficiency in Africa is under strong natural selection from the preferential protection it provides to hemizygous males against life-threatening malaria. Little or no such protection is present among heterozygous females. Although these

X-Linked G6PD Deficiency Protects Hemizygous Males but Not Heterozygous Females against Severe Malaria

PubMed Central

Doumbo, Ogobara K; Wellems, Thomas E; Diallo, Dapa A

2007-01-01

Background Glucose-6-phosphate dehydrogenase (G6PD) is important in the control of oxidant stress in erythrocytes, the host cells for Plasmodium falciparum. Mutations in this enzyme produce X-linked deficiency states associated with protection against malaria, notably in Africa where the A− form of G6PD deficiency is widespread. Some reports have proposed that heterozygous females with mosaic populations of normal and deficient erythrocytes (due to random X chromosome inactivation) have malaria resistance similar to or greater than hemizygous males with populations of uniformly deficient erythrocytes. These proposals are paradoxical, and they are not consistent with currently hypothesized mechanisms of protection. Methods and Findings We conducted large case-control studies of the A− form of G6PD deficiency in cases of severe or uncomplicated malaria among two ethnic populations of rural Mali, West Africa, where malaria is hyperendemic. Our results indicate that the uniform state of G6PD deficiency in hemizygous male children conferred significant protection against severe, life-threatening malaria, and that it may have likewise protected homozygous female children. No such protection was evident from the mosaic state of G6PD deficiency in heterozygous females. We also found no significant differences in the parasite densities of males and females with differences in G6PD status. Pooled odds ratios from meta-analysis of our data and data from a previous study confirmed highly significant protection against severe malaria in hemizygous males but not in heterozygous females. Among the different forms of severe malaria, protection was principally evident against cerebral malaria, the most frequent form of life-threatening malaria in these studies. Conclusions The A− form of G6PD deficiency in Africa is under strong natural selection from the preferential protection it provides to hemizygous males against life-threatening malaria. Little or no such protection is

Understanding the link between malaria risk and climate.

PubMed

Paaijmans, Krijn P; Read, Andrew F; Thomas, Matthew B

2009-08-18

The incubation period for malaria parasites within the mosquito is exquisitely temperature-sensitive, so that temperature is a major determinant of malaria risk. Epidemiological models are increasingly used to guide allocation of disease control resources and to assess the likely impact of climate change on global malaria burdens. Temperature-based malaria transmission is generally incorporated into these models using mean monthly temperatures, yet temperatures fluctuate throughout the diurnal cycle. Here we use a thermodynamic malaria development model to demonstrate that temperature fluctuation can substantially alter the incubation period of the parasite, and hence malaria transmission rates. We find that, in general, temperature fluctuation reduces the impact of increases in mean temperature. Diurnal temperature fluctuation around means >21 degrees C slows parasite development compared with constant temperatures, whereas fluctuation around <21 degrees C speeds development. Consequently, models which ignore diurnal variation overestimate malaria risk in warmer environments and underestimate risk in cooler environments. To illustrate the implications further, we explore the influence of diurnal temperature fluctuation on malaria transmission at a site in the Kenyan Highlands. Based on local meteorological data, we find that the annual epidemics of malaria at this site cannot be explained without invoking the influence of diurnal temperature fluctuation. Moreover, while temperature fluctuation reduces the relative influence of a subtle warming trend apparent over the last 20 years, it nonetheless makes the effects biologically more significant. Such effects of short-term temperature fluctuations have not previously been considered but are central to understanding current malaria transmission and the consequences of climate change.

The feasibility, patterns of use and acceptability of using mobile phone text-messaging to improve treatment adherence and post-treatment review of children with uncomplicated malaria in western Kenya.

PubMed

Otieno, Gabriel; Githinji, Sophie; Jones, Caroline; Snow, Robert W; Talisuna, Ambrose; Zurovac, Dejan

2014-02-03

Trials evaluating the impact of mobile phone text-messaging to support management of acute diseases, such as malaria, are urgently needed in Africa. There has been however a concern about the feasibility of interventions that rely on access to mobile phones among caregivers in rural areas. To assess the feasibility and inform development of an intervention to improve adherence to malaria medications and post-treatment review, mobile phone network, access, ownership and use among caregivers in western Kenya was assessed. A cross-sectional survey based on outpatient exit interviews was undertaken among caregivers of children with malaria at four trial facilities. The main outcomes were proportions of caregivers that have mobile signal at home; have access to mobile phones; are able to read; and use text-messaging. Willingness to receive text-message reminders was also explored. Descriptive analyses were performed. Of 400 interviewed caregivers, the majority were female (93.5%), mothers of the sick children (87.8%) and able to read (97.3%). Only 1.7% of caregivers were without any education. Nearly all (99.8%) reported access to a mobile signal at home. 93.0% (site range: 89-98%) had access to a mobile phone within their household while 73.8% (site range: 66-78%) possessed a personal phone. Among caregivers with mobile phone access, 93.6% (site range: 85-99%) used the phone to receive text-messages. Despite only 19% having electricity at home nearly all (99.7%) caregivers reported that they would be able to have permanent phone access to receive text-messages in the next 28 days. Willingness to receive text-message reminders was nearly universal (99.7%) with 41.7% of caregivers preferring texts in English, 32.3% in Kiswahili and 26.1% in Dholuo. Despite concerns that the feasibility of text-messaging interventions targeting caregivers may be compromised in rural high malaria risk areas in Kenya, very favourable conditions were found with respect to mobile network

State Limitations, Self-Help Secondary Schooling, and Development in Kenya.

ERIC Educational Resources Information Center

Bradshaw, York W.

1993-01-01

Over 60% of Kenya's secondary schools are nongovernment community-run schools. Analysis of district-level data on adult literacy, secondary enrollment, child health and mortality, malaria prevalence, and rural development indicates that government schooling has few effects. Nongovernment schooling is associated with lower child mortality and other…

Utilizing Satellite Precipitation Products to Understand the Link Between Climate Variability and Malaria

NASA Astrophysics Data System (ADS)

Maggioni, V.; Mousam, A.; Delamater, P. L.; Cash, B. A.; Quispe, A.

2015-12-01

Malaria is a public health threat to people globally leading to 198 million cases and 584,000 deaths annually. Outbreaks of vector borne diseases such as malaria can be significantly impacted by climate variables such as precipitation. For example, an increase in rainfall has the potential to create pools of water that can serve as breeding locations for mosquitos. Peru is a country that is currently controlling malaria, but has not been able to completely eliminate the disease. Despite the various initiatives in order to control malaria - including regional efforts to improve surveillance, early detection, prompt treatment, and vector management - malaria cases in Peru have risen between 2011 and 2014. The purpose of this study is to test the hypothesis that climate variability plays a fundamental role in malaria occurrence over a 12-year period (2003-2014) in Peru. When analyzing climate variability, it is important to obtain high-quality, high-resolution data for a time series long enough to draw conclusion about how climate variables have been and are changing. Remote sensing is a powerful tool for measuring and monitoring climate variables continuously in time and space. A widely used satellite-based precipitation product, the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA), available globally since 1998, was used to obtain 3-hourly data with a spatial resolution of 0.25° x 0.25°. The precipitation data was linked to weekly (2003-2014) malaria cases collected by health centers and available at a district level all over Peru to investigate the relationship between precipitation and the seasonal and annual variations in malaria incidence. Further studies will incorporate additional climate variables such as temperature, humidity, soil moisture, and surface pressure from remote sensing data products and climate models. Ultimately, this research will help us to understand if climate variability impacts malaria incidence

Assessment of mosquito larval productivity among different land use types for targeted malaria vector control in the western Kenya highlands.

PubMed

Kweka, Eliningaya J; Munga, Stephen; Himeidan, Yousif; Githeko, Andrew K; Yan, Guyuin

2015-07-05

Mosquito larval source management (LSM) is likely to be more effective when adequate information such as dominant species, seasonal abundance, type of productive habitat, and land use type are available for targeted sites. LSM has been an effective strategy for reducing malaria morbidity in both urban and rural areas in Africa where sufficient proportions of larval habitats can be targeted. In this study, we conducted longitudinal larval source surveillance in the western Kenya highlands, generating data which can be used to establish cost-effective targeted intervention tools. One hundred and twenty-four (124) positive larval habitats were monitored weekly and sampled for mosquito larvae over the 85-week period from 28 July 2009 to 3 March 2011. Two villages in the western Kenya highlands, Mbale and Iguhu, were included in the study. After preliminary sampling, habitats were classified into four types: hoof prints (n = 21; 17 % of total), swamps (n = 32; 26%), abandoned goldmines (n = 35; 28%) and drainage ditches (n = 36; 29%). Positive habitats occurred in two land use types: farmland (66) and pasture (58). No positive larval habitats occurred in shrub land or forest. A total of 46,846 larvae were sampled, of which 44.1% (20,907) were from abandoned goldmines, 30.9% (14,469) from drainage ditches, 22.4% (10,499) from swamps and 2.1% (971) from hoof prints. In terms of land use types, 57.2% (26,799) of the sampled larvae were from pasture and 42.8% (20,047) were from farmland. Of the specimens identified morphologically, 24,583 (52.5%) were Anopheles gambiae s.l., 11,901 (25.4%) were Culex quinquefasciatus, 5628 (12%) were An. funestus s.l. and 4734 (10.1%) were other anopheline species (An. coustani, An. squamosus, An. ziemanni or An. implexus). Malaria vector dynamics varied seasonally, with An.gambiae s.s. dominating during wet season and An.arabiensis during dry season. An increased proportion of An. arabiensis was observed compared to

Differing Burden and Epidemiology of Non-Typhi Salmonella Bacteremia in Rural and Urban Kenya, 2006–2009

PubMed Central

Tabu, Collins; Breiman, Robert F.; Ochieng, Benjamin; Aura, Barrack; Cosmas, Leonard; Audi, Allan; Olack, Beatrice; Bigogo, Godfrey; Ongus, Juliette R.; Fields, Patricia; Mintz, Eric; Burton, Deron; Oundo, Joe; Feikin, Daniel R.

2012-01-01

Background The epidemiology of non-Typhi Salmonella (NTS) bacteremia in Africa will likely evolve as potential co-factors, such as HIV, malaria, and urbanization, also change. Methods As part of population-based surveillance among 55,000 persons in malaria-endemic, rural and malaria-nonendemic, urban Kenya from 2006–2009, blood cultures were obtained from patients presenting to referral clinics with fever ≥38.0°C or severe acute respiratory infection. Incidence rates were adjusted based on persons with compatible illnesses, but whose blood was not cultured. Results NTS accounted for 60/155 (39%) of blood culture isolates in the rural and 7/230 (3%) in the urban sites. The adjusted incidence in the rural site was 568/100,000 person-years, and the urban site was 51/100,000 person-years. In both sites, the incidence was highest in children <5 years old. The NTS-to-typhoid bacteremia ratio in the rural site was 4.6 and in the urban site was 0.05. S. Typhimurium represented >85% of blood NTS isolates in both sites, but only 21% (urban) and 64% (rural) of stool NTS isolates. Overall, 76% of S. Typhimurium blood isolates were multi-drug resistant, most of which had an identical profile in Pulse Field Gel Electrophoresis. In the rural site, the incidence of NTS bacteremia increased during the study period, concomitant with rising malaria prevalence (monthly correlation of malaria positive blood smears and NTS bacteremia cases, Spearman's correlation, p = 0.018 for children, p = 0.16 adults). In the rural site, 80% of adults with NTS bacteremia were HIV-infected. Six of 7 deaths within 90 days of NTS bacteremia had HIV/AIDS as the primary cause of death assigned on verbal autopsy. Conclusions NTS caused the majority of bacteremias in rural Kenya, but typhoid predominated in urban Kenya, which most likely reflects differences in malaria endemicity. Control measures for malaria, as well as HIV, will likely decrease the burden of NTS bacteremia in Africa. PMID

Plasmodium infection, anaemia and mosquito net use among school children across different settings in Kenya.

PubMed

Gitonga, Caroline W; Edwards, Tansy; Karanja, Peris N; Noor, Abdisalan M; Snow, Robert W; Brooker, Simon J

2012-07-01

To investigate risk factors, including reported net use, for Plasmodium infection and anaemia among school children and to explore variations in effects across different malaria ecologies occurring in Kenya. This study analysed data for 49 975 school children in 480 schools surveyed during a national school malaria survey, 2008-2010. Mixed effects logistic regression was used to investigate factors associated with Plasmodium infection and anaemia within different malaria transmission zones. Insecticide-treated net (ITN) use was associated with reduction in the odds of Plasmodium infection in coastal and western highlands epidemic zones and among boys in the lakeside high transmission zone. Other risk factors for Plasmodium infection and for anaemia also varied by zone. Plasmodium infection was negatively associated with increasing socio-economic status in all transmission settings, except in the semi-arid north-east zone. Plasmodium infection was a risk factor for anaemia in lakeside high transmission, western highlands epidemic and central low-risk zones, whereas ITN use was only associated with lower levels of anaemia in coastal and central zones and among boys in the lakeside high transmission zone. The risk factors for Plasmodium infection and anaemia, including the protective associations with ITN use, vary according to malaria transmission settings in Kenya, and future efforts to control malaria and anaemia should take into account such heterogeneities among school children. © 2012 Blackwell Publishing Ltd.

Evaluation of the Parasight Platform for Malaria Diagnosis

PubMed Central

Eshel, Yochay; Houri-Yafin, Arnon; Benkuzari, Hagai; Lezmy, Natalie; Soni, Mamta; Charles, Malini; Swaminathan, Jayanthi; Solomon, Hilda; Sampathkumar, Pavithra; Premji, Zul; Mbithi, Caroline; Nneka, Zaitun; Onsongo, Simon; Maina, Daniel; Levy-Schreier, Sarah; Cohen, Caitlin Lee; Gluck, Dan; Pollak, Joseph Joel

2016-01-01

ABSTRACT The World Health Organization estimates that nearly 500 million malaria tests are performed annually. While microscopy and rapid diagnostic tests (RDTs) are the main diagnostic approaches, no single method is inexpensive, rapid, and highly accurate. Two recent studies from our group have demonstrated a prototype computer vision platform that meets those needs. Here we present the results from two clinical studies on the commercially available version of this technology, the Sight Diagnostics Parasight platform, which provides malaria diagnosis, species identification, and parasite quantification. We conducted a multisite trial in Chennai, India (Apollo Hospital [n = 205]), and Nairobi, Kenya (Aga Khan University Hospital [n = 263]), in which we compared the device to microscopy, RDTs, and PCR. For identification of malaria, the device performed similarly well in both contexts (sensitivity of 99% and specificity of 100% at the Indian site and sensitivity of 99.3% and specificity of 98.9% at the Kenyan site, compared to PCR). For species identification, the device correctly identified 100% of samples with Plasmodium vivax and 100% of samples with Plasmodium falciparum in India and 100% of samples with P. vivax and 96.1% of samples with P. falciparum in Kenya, compared to PCR. Lastly, comparisons of the device parasite counts with those of trained microscopists produced average Pearson correlation coefficients of 0.84 at the Indian site and 0.85 at the Kenyan site. PMID:27974542

Towards Near Real-time Convective Rainfall Observations over Kenya

NASA Astrophysics Data System (ADS)

Hoedjes, Joost; Said, Mohammed; Becht, Robert; Kifugo, Shem; Kooiman, André; Limo, Agnes; Maathuis, Ben; Moore, Ian; Mumo, Mark; Nduhiu Mathenge, Joseph; Su, Bob; Wright, Iain

2013-04-01

The existing meteorological infrastructure in Kenya is poorly suited for the countrywide real-time monitoring of precipitation. Rainfall radar is not available, and the existing network of rain gauges is sparse and challenging to maintain. This severely restricts Kenya's capacity to warn for, and respond to, weather related emergencies. Furthermore, the lack of accurate rainfall observations severely limits Kenya's climate change adaptation capabilities. Over the past decade, the mobile telephone network in Kenya has expanded rapidly. This network makes extensive use of terrestrial microwave (MW) links, received signal level (RSL) data from which can be used for the calculation of rainfall intensities. We present a novel method for the near-real time observation of convective rainfall over Kenya, based on the combined use of MW RSL data and Meteosat Second Generation (MSG) satellite data. In this study, the variable density rainfall information derived from several MW links is scaled up using MSG data to provide full rainfall information coverage for the region surrounding the links. Combining MSG data and MW link derived rainfall data for several adjacent MW links makes it possible to make the distinction between wet and dry pixels. This allows the disaggregation of the MW link derived rainfall intensities. With the distinction between wet and dry pixels made, and the MW derived rainfall intensities disaggregated, these data can then be used to develop instantaneous empirical relationships linking rainfall intensities to cloud physical properties. These relationships are then used to calculate rainfall intensities for the MSG scene. Since both the MSG and the MW data are available at the same temporal resolution, unique empirical coefficients can be determined for each interval. This approach ensures that changes in convective conditions from one interval to the next are taken into account. Initial results from a pilot study, which took place from November 2012

Blood stage malaria vaccine eliciting high antigen-specific antibody concentrations confers no protection to young children in Western Kenya.

PubMed

Ogutu, Bernhards R; Apollo, Odika J; McKinney, Denise; Okoth, Willis; Siangla, Joram; Dubovsky, Filip; Tucker, Kathryn; Waitumbi, John N; Diggs, Carter; Wittes, Janet; Malkin, Elissa; Leach, Amanda; Soisson, Lorraine A; Milman, Jessica B; Otieno, Lucas; Holland, Carolyn A; Polhemus, Mark; Remich, Shon A; Ockenhouse, Christian F; Cohen, Joe; Ballou, W Ripley; Martin, Samuel K; Angov, Evelina; Stewart, V Ann; Lyon, Jeffrey A; Heppner, D Gray; Withers, Mark R

2009-01-01

The antigen, falciparum malaria protein 1 (FMP1), represents the 42-kDa C-terminal fragment of merozoite surface protein-1 (MSP-1) of the 3D7 clone of P. falciparum. Formulated with AS02 (a proprietary Adjuvant System), it constitutes the FMP1/AS02 candidate malaria vaccine. We evaluated this vaccine's safety, immunogenicity, and efficacy in African children. A randomised, double-blind, Phase IIb, comparator-controlled trial.The trial was conducted in 13 field stations of one mile radii within Kombewa Division, Nyanza Province, Western Kenya, an area of holoendemic transmission of P. falciparum. We enrolled 400 children aged 12-47 months in general good health.Children were randomised in a 1ratio1 fashion to receive either FMP1/AS02 (50 microg) or Rabipur(R) rabies vaccine. Vaccinations were administered on a 0, 1, and 2 month schedule. The primary study endpoint was time to first clinical episode of P. falciparum malaria (temperature >/=37.5 degrees C with asexual parasitaemia of >/=50,000 parasites/microL of blood) occurring between 14 days and six months after a third dose. Case detection was both active and passive. Safety and immunogenicity were evaluated for eight months after first immunisations; vaccine efficacy (VE) was measured over a six-month period following third vaccinations. 374 of 400 children received all three doses and completed six months of follow-up. FMP1/AS02 had a good safety profile and was well-tolerated but more reactogenic than the comparator. Geometric mean anti-MSP-1(42) antibody concentrations increased from1.3 microg/mL to 27.3 microg/mL in the FMP1/AS02 recipients, but were unchanged in controls. 97 children in the FMP1/AS02 group and 98 controls had a primary endpoint episode. Overall VE was 5.1% (95% CI: -26% to +28%; p-value = 0.7). FMP1/AS02 is not a promising candidate for further development as a monovalent malaria vaccine. Future MSP-1(42) vaccine development should focus on other formulations and antigen constructs

Blood Stage Malaria Vaccine Eliciting High Antigen-Specific Antibody Concentrations Confers No Protection to Young Children in Western Kenya

PubMed Central

Ogutu, Bernhards R.; Apollo, Odika J.; McKinney, Denise; Okoth, Willis; Siangla, Joram; Dubovsky, Filip; Tucker, Kathryn; Waitumbi, John N.; Diggs, Carter; Wittes, Janet; Malkin, Elissa; Leach, Amanda; Soisson, Lorraine A.; Milman, Jessica B.; Otieno, Lucas; Holland, Carolyn A.; Polhemus, Mark; Remich, Shon A.; Ockenhouse, Christian F.; Cohen, Joe; Ballou, W. Ripley; Martin, Samuel K.; Angov, Evelina; Stewart, V. Ann; Lyon, Jeffrey A.; Heppner, D. Gray; Withers, Mark R.

2009-01-01

Objective The antigen, falciparum malaria protein 1 (FMP1), represents the 42-kDa C-terminal fragment of merozoite surface protein-1 (MSP-1) of the 3D7 clone of P. falciparum. Formulated with AS02 (a proprietary Adjuvant System), it constitutes the FMP1/AS02 candidate malaria vaccine. We evaluated this vaccine's safety, immunogenicity, and efficacy in African children. Methods A randomised, double-blind, Phase IIb, comparator-controlled trial.The trial was conducted in 13 field stations of one mile radii within Kombewa Division, Nyanza Province, Western Kenya, an area of holoendemic transmission of P. falciparum. We enrolled 400 children aged 12–47 months in general good health.Children were randomised in a 1∶1 fashion to receive either FMP1/AS02 (50 µg) or Rabipur® rabies vaccine. Vaccinations were administered on a 0, 1, and 2 month schedule. The primary study endpoint was time to first clinical episode of P. falciparum malaria (temperature ≥37.5°C with asexual parasitaemia of ≥50,000 parasites/µL of blood) occurring between 14 days and six months after a third dose. Case detection was both active and passive. Safety and immunogenicity were evaluated for eight months after first immunisations; vaccine efficacy (VE) was measured over a six-month period following third vaccinations. Results 374 of 400 children received all three doses and completed six months of follow-up. FMP1/AS02 had a good safety profile and was well-tolerated but more reactogenic than the comparator. Geometric mean anti-MSP-142 antibody concentrations increased from1.3 µg/mL to 27.3 µg/mL in the FMP1/AS02 recipients, but were unchanged in controls. 97 children in the FMP1/AS02 group and 98 controls had a primary endpoint episode. Overall VE was 5.1% (95% CI: −26% to +28%; p-value = 0.7). Conclusions FMP1/AS02 is not a promising candidate for further development as a monovalent malaria vaccine. Future MSP-142 vaccine development should focus on other formulations and antigen

The capacity of diagnostic laboratories in Kenya for detecting infectious diseases.

PubMed

Slotved, H-C; Yatich, Kennedy K; Sam, Shem Otoi; Ndhine, Edwardina Otieno

2017-01-01

The aim of this study is to present data of the diagnostic capacity of Kenyan laboratories to diagnose a number of human pathogens. The study is based on the data obtained from a biosecurity survey conducted in Kenya in 2014/2015 and data from the Statistical Abstract of Kenya for 2015. The biosecurity survey has previously been published; however, the survey also included information on laboratory capacity to handle a number of pathogens, which have not been published. Data were retrieved from the survey on 86 laboratory facilities. The data include information from relevant categories such as training laboratories, human diagnostic laboratories, veterinary diagnostic laboratories, and research laboratories. The disease incidence in Kenya ranges widely from malaria and diarrhea with an incidence rate of around 10.000 per year to diseases such as cholera and yellow fever with an incidence rate of 1 per year or less for all age groups. The data showed that diseases with the highest number of diagnostic facilities were mainly malaria-, HIV-, tuberculosis-, and diarrhea-related infectious diseases. The study generally shows that the laboratory facilities have the capacity of detecting the infectious diseases with the highest incidence rates. Furthermore, it seems that the number of facilities able to detect a particular disease is related to the incidence rate of the disease.

Access and use of interventions to prevent and treat malaria among pregnant women in Kenya and Mali: a qualitative study.

PubMed

Hill, Jenny; Kayentao, Kassoum; Achieng, Florence; Diarra, Samba; Dellicour, Stephanie; Diawara, Sory I; Hamel, Mary J; Ouma, Peter; Desai, Meghna; Doumbo, Ogobara K; ter Kuile, Feiko O; Webster, Jayne

2015-01-01

Coverage of malaria in pregnancy interventions in sub-Saharan Africa is suboptimal. We undertook a systematic examination of the operational, socio-economic and cultural constraints to pregnant women's access to intermittent preventive treatment (IPTp), long-lasting insecticide-treated nets (LLINs) and case management in Kenya and Mali to provide empirical evidence for strategies to improve coverage. Focus group discussions (FGDs) were held as part of a programme of research to explore the delivery, access and use of interventions to control malaria in pregnancy. FGDs were held with four sub-groups: non-pregnant women of child bearing age (aged 15-49 years), pregnant women or mothers of children aged <1 year, adolescent women, and men. Content analysis was used to develop themes and sub-themes from the data. Women and men's perceptions of the benefits of antenatal care were generally positive; motivation among women consisted of maintaining a healthy pregnancy, disease prevention in mother and foetus, checking the position of the baby in preparation for delivery, and ensuring admission to a facility in case of complications. Barriers to accessing care related to the quality of the health provider-client interaction, perceived health provider skills and malpractice, drug availability, and cost of services. Pregnant women perceived themselves and their babies at particular risk from malaria, and valued diagnosis and treatment from a health professional, but cost of treatment at health facilities drove women to use herbal remedies or drugs bought from shops. Women lacked information on the safety, efficacy and side effects of antimalarial use in pregnancy. Women in these settings appreciated the benefits of antenatal care and yet health services in both countries are losing women to follow-up due to factors that can be improved with greater political will. Antenatal services need to be patient-centred, free-of-charge or highly affordable and accountable to the women

Does anti-malarial drug knowledge predict anti-malarial dispensing practice in drug outlets? A survey of medicine retailers in western Kenya.

PubMed

Rusk, Andria; Smith, Nathan; Menya, Diana; Obala, Andrew; Simiyu, Chrispinus; Khwa-Otsyula, Barasa; O'Meara, Wendy

2012-08-06

Malaria is a major cause of morbidity and mortality in Kenya, where it is the fifth leading cause of death in both children and adults. Effectively managing malaria is dependent upon appropriate treatment. In Kenya, between 17 to 83 percent of febrile individuals first seek treatment for febrile illness over the counter from medicine retailers. Understanding medicine retailer knowledge and behaviour in treating suspected malaria and dispensing anti-malarials is crucial. To investigate medicine retailer knowledge about anti-malarials and their dispensing practices, a survey was conducted of all retail drug outlets that sell anti-malarial medications and serve residents of the Webuye Health and Demographic Surveillance Site in the Bungoma East District of western Kenya. Most of the medicine retailers surveyed (65%) were able to identify artemether-lumefantrine (AL) as the Kenyan Ministry of Health recommended first-line anti-malarial therapy for uncomplicated malaria. Retailers who correctly identified this treatment were also more likely to recommend AL to adult and paediatric customers. However, the proportion of medicine retailers who recommend the correct treatment is disappointingly low. Only 48% would recommend AL to adults, and 37% would recommend it to children. It was discovered that customer demand has an influence on retailer behaviour. Retailer training and education were found to be correlated with anti-malarial drug knowledge, which in turn is correlated with dispensing practices. Medicine retailer behaviour, including patient referral practice and dispensing practices, are also correlated with knowledge of the first-line anti-malarial medication. The Kenya Ministry of Health guidelines were found to influence retailer drug stocking and dispensing behaviours. Most medicine retailers could identify the recommended first-line treatment for uncomplicated malaria, but the percentage that could not is still too high. Furthermore, knowing the MOH recommended

Malaria vector abundance is associated with house structures in Baringo County, Kenya.

PubMed

Ondiba, Isabella M; Oyieke, Florence A; Ong'amo, George O; Olumula, Macrae M; Nyamongo, Isaac K; Estambale, Benson B A

2018-01-01

Malaria, a major cause of morbidity and mortality, is the most prevalent vector borne disease in Baringo County; a region which has varied house designs in arid and semi-arid areas. This study investigated the association between house structures and indoor-malaria vector abundance in Baringo County. The density of malaria vectors in houses with open eaves was higher than that for houses with closed eaves. Grass thatched roof houses had higher density of malaria vectors than corrugated iron sheet roofs. Similarly, mud walled houses had higher vector density than other wall types. Houses in the riverine zone were significantly associated with malaria vector abundance (p<0.000) possibly due to more varied house structures. In Kamnarok village within riverine zone, a house made of grass thatched roof and mud wall but raised on stilts with domestic animals (sheep/goats) kept at the lower level had lower mosquito density (5.8 per collection) than ordinary houses made of same materials but at ground level (30.5 mosquitoes per collection), suggestive of a change in behavior of mosquito feeding and resting. House modifications such as screening of eaves, improvement of construction material and building stilted houses can be incorporated in the integrated vector management (IVM) strategy to complement insecticide treated bed nets and indoor residual spray to reduce indoor malaria vector density.

Density-dependent blood stage Plasmodium falciparum suppresses malaria super-infection in a malaria holoendemic population.

PubMed

Pinkevych, Mykola; Petravic, Janka; Chelimo, Kiprotich; Vulule, John; Kazura, James W; Moormann, Ann M; Davenport, Miles P

2013-11-01

Recent studies of Plasmodium berghei malaria in mice show that high blood-stage parasitemia levels inhibit the development of subsequent liver-stage infections. Whether a similar inhibitory effect on liver-stage Plasmodium falciparum by blood-stage infection occurs in humans is unknown. We have analyzed data from a treatment-time-to-infection cohort of children < 10 years of age residing in a malaria holoendemic area of Kenya where people experience a new blood-stage infection approximately every 2 weeks. We hypothesized that if high parasitemia blocked the liver stage, then high levels of parasitemia should be followed by a "skipped" peak of parasitemia. Statistical analysis of "natural infection" field data and stochastic simulation of infection dynamics show that the data are consistent with high P. falciparum parasitemia inhibiting liver-stage parasite development in humans.

Perceptions of malaria and acceptance of rapid diagnostic tests and related treatment practises among community members and health care providers in Greater Garissa, North Eastern Province, Kenya.

PubMed

Diggle, Emma; Asgary, Ramin; Gore-Langton, Georgia; Nahashon, Erupe; Mungai, James; Harrison, Rebecca; Abagira, Abdullahi; Eves, Katie; Grigoryan, Zoya; Soti, David; Juma, Elizabeth; Allan, Richard

2014-12-17

Conventional diagnosis of malaria has relied upon either clinical diagnosis or microscopic examination of peripheral blood smears. These methods, if not carried out exactly, easily result in the over- or under-diagnosis of malaria. The reliability and accuracy of malaria RDTs, even in extremely challenging health care settings, have made them a staple in malaria control programmes. Using the setting of a pilot introduction of malaria RDTs in Greater Garissa, North Eastern Province, Kenya, this study aims to identify and understand perceptions regarding malaria diagnosis, with a particular focus on RDTs, and treatment among community members and health care workers (HCWs). The study was conducted in five districts of Garissa County. Focus group discussions (FGD) were performed with community members that were recruited from health facilities (HFs) supported by the MENTOR Initiative. In-depth interviews (IDIs) and FGDs with HCWs were also carried out. Interview transcripts were then coded and analysed for major themes. Two researchers reviewed all codes, first separately and then together, discussed the specific categories, and finally characterized, described, and agreed upon major important themes. Thirty-four FGDs were carried out with a range of two to eight participants (median of four). Of 157 community members, 103 (65.6%) were women. The majority of participants were illiterate and the highest level of education was secondary school. Some 76% of participants were of Somali ethnicity. Whilst community members and HCWs demonstrated knowledge of aspects of malaria transmission, prevention, diagnosis, and treatment, gaps and misconceptions were identified. Poor adherence to negative RDT results, unfamiliarity and distrust of RDTs, and an inconsistent RDT supply were the main challenges to become apparent in FGDs and IDIs. Gaps in knowledge or incorrect beliefs exist in Greater Garissa and have the potential to act as barriers to complete and correct malaria case

In-depth comparative analysis of malaria parasite genomes reveals protein-coding genes linked to human disease in Plasmodium falciparum genome.

PubMed

Liu, Xuewu; Wang, Yuanyuan; Liang, Jiao; Wang, Luojun; Qin, Na; Zhao, Ya; Zhao, Gang

2018-05-02

Plasmodium falciparum is the most virulent malaria parasite capable of parasitizing human erythrocytes. The identification of genes related to this capability can enhance our understanding of the molecular mechanisms underlying human malaria and lead to the development of new therapeutic strategies for malaria control. With the availability of several malaria parasite genome sequences, performing computational analysis is now a practical strategy to identify genes contributing to this disease. Here, we developed and used a virtual genome method to assign 33,314 genes from three human malaria parasites, namely, P. falciparum, P. knowlesi and P. vivax, and three rodent malaria parasites, namely, P. berghei, P. chabaudi and P. yoelii, to 4605 clusters. Each cluster consisted of genes whose protein sequences were significantly similar and was considered as a virtual gene. Comparing the enriched values of all clusters in human malaria parasites with those in rodent malaria parasites revealed 115 P. falciparum genes putatively responsible for parasitizing human erythrocytes. These genes are mainly located in the chromosome internal regions and participate in many biological processes, including membrane protein trafficking and thiamine biosynthesis. Meanwhile, 289 P. berghei genes were included in the rodent parasite-enriched clusters. Most are located in subtelomeric regions and encode erythrocyte surface proteins. Comparing cluster values in P. falciparum with those in P. vivax and P. knowlesi revealed 493 candidate genes linked to virulence. Some of them encode proteins present on the erythrocyte surface and participate in cytoadhesion, virulence factor trafficking, or erythrocyte invasion, but many genes with unknown function were also identified. Cerebral malaria is characterized by accumulation of infected erythrocytes at trophozoite stage in brain microvascular. To discover cerebral malaria-related genes, fast Fourier transformation (FFT) was introduced to extract

On the use of RADARSAT-1 for monitoring malaria risk in Kenya

NASA Astrophysics Data System (ADS)

Ross, S. G.; Thomson, M. C.; Pultz, T.; Mbogo, C. M.; Regens, J. L.; Swalm, C.; Githure, J.; Yan, G.; Gu, W.; Beier, J. C.

2002-01-01

The incidence and spread of vector-borne infectious diseases are increasing concerns in many parts of the world. Earth obervation techniques provide a recognised means for monitoring and mapping disease risk as well as correlating environmental indicators with various disease vectors. Because the areas most impacted by vector-borne disease are remote and not easily monitored using traditional, labor intensive survey techniques, high spatial and temporal coverage provided by spaceborne sensors allows for the investigation of large areas in a timely manner. However, since the majority of infectious diseases occur in tropical areas, one of the main barriers to earth observation techniques is persistent cloud-cover. Synthetic Aperture Radar (SAR) technology offers a solution to this problem by providing all-weather, day and night imaging capability. Based on SAR's sensitivity to target moisture conditions, sensors such as RADARSAT-1 can be readily used to map wetland and swampy areas that are conducive to functioning as aquatic larval habitats. Irrigation patterns, deforestation practises and the effects of local flooding can be monitored using SAR imagery, and related to potential disease vector abundance and proximity to populated areas. This paper discusses the contribution of C-band radar remote sensing technology to monitoring and mapping malaria. Preliminary results using RADARSAT-1 for identifying areas of high mosquito (Anopheles gambiae s.l.) abundance along the Kenya coast will be discussed. The authors consider the potential of RADARSAT-1 data based on SAR sensor characteristics and the preliminary results obtained. Further potential of spaceborne SAR data for monitoring vector-borne disease is discussed with respect to future advanced SAR sensors such as RADARSAT-2.

Reproductive health issues in rural Western Kenya.

PubMed

van Eijk, Anna M; Lindblade, Kim A; Odhiambo, Frank; Peterson, Elizabeth; Sikuku, Evallyne; Ayisi, John G; Ouma, Peter; Rosen, Daniel H; Slutsker, Laurence

2008-03-18

We describe reproductive health issues among pregnant women in a rural area of Kenya with a high coverage of insecticide treated nets (ITNs) and high prevalence of HIV (15%). We conducted a community-based cross-sectional survey among rural pregnant women in western Kenya. A medical, obstetric and reproductive history was obtained. Blood was obtained for a malaria smear and haemoglobin level, and stool was examined for geohelminths. Height and weight were measured. Of 673 participants, 87% were multigravidae and 50% were in their third trimester; 41% had started antenatal clinic visits at the time of interview and 69% reported ITN-use. Malaria parasitemia and anaemia (haemoglobin < 11 g/dl) were detected among 36% and 53% of the women, respectively. Geohelminth infections were detected among 76% of the 390 women who gave a stool sample. Twenty percent of women were underweight, and sixteen percent reported symptoms of herpes zoster or oral thrush in the last two months. Nineteen percent of all women reported using a contraceptive method to delay or prevent pregnancy before the current pregnancy (injection 10%, pill 8%, condom 0.4%). Twenty-three percent of multigravidae conceived their current pregnancy within a year of the previous pregnancy. More than half of the multigravidae (55%) had ever lost a live born child and 21% had lost their last singleton live born child at the time of interview. In this rural area with a high HIV prevalence, the reported use of condoms before pregnancy was extremely low. Pregnancy health was not optimal with a high prevalence of malaria, geohelminth infections, anaemia and underweight. Chances of losing a child after birth were high. Multiple interventions are needed to improve reproductive health in this area.

Can plant biotechnology help break the HIV-malaria link?

PubMed

Vamvaka, E; Twyman, R M; Christou, P; Capell, T

2014-01-01

The population of sub-Saharan Africa is at risk from multiple, poverty-related endemic diseases. HIV and malaria are the most prevalent, but they disproportionately affect different groups of people, i.e. HIV predominantly affects sexually-active adults whereas malaria has a greater impact on children and pregnant women. Nevertheless, there is a significant geographical and epidemiological overlap which results in bidirectional and synergistic interactions with important consequences for public health. The immunosuppressive effects of HIV increase the risk of infection when individuals are exposed to malaria parasites and also the severity of malaria symptoms. Similarly, acute malaria can induce a temporary increase in the HIV viral load. HIV is associated with a wide range of opportunistic infections that can be misdiagnosed as malaria, resulting in the wasteful misuse of antimalarial drugs and a failure to address the genuine cause of the disease. There is also a cumulative risk of toxicity when antiretroviral and antimalarial drugs are given to the same patients. Synergistic approaches involving the control of malaria as a strategy to fight HIV/AIDS and vice versa are therefore needed in co-endemic areas. Plant biotechnology has emerged as a promising approach to tackle poverty-related diseases because plant-derived drugs and vaccines can be produced inexpensively in developing countries and may be distributed using agricultural infrastructure without the need for a cold chain. Here we explore some of the potential contributions of plant biotechnology and its integration into broader multidisciplinary public health programs to combat the two diseases in developing countries. Copyright © 2014 Elsevier Inc. All rights reserved.

Assessing the impact of model and climate uncertainty in malaria simulations for the Kenyan Highlands.

NASA Astrophysics Data System (ADS)

Tompkins, A. M.; Thomson, M. C.

2017-12-01

Simulations of the impact of climate variations on a vector-bornedisease such as malaria are subject to a number of sources ofuncertainty. These include the model structure and parameter settingsin addition to errors in the climate data and the neglect of theirspatial heterogeneity, especially over complex terrain. We use aconstrained genetic algorithm to confront these two sources ofuncertainty for malaria transmission in the highlands of Kenya. Thetechnique calibrates the parameter settings of a process-based,mathematical model of malaria transmission to vary within theirassessed level of uncertainty and also allows the calibration of thedriving climate data. The simulations show that in highland settingsclose to the threshold for sustained transmission, the uncertainty inclimate is more important to address than the malaria modeluncertainty. Applications of the coupled climate-malaria modelling system are briefly presented.

A Reversal in Reductions of Child Mortality in Western Kenya, 2003–2009

PubMed Central

Hamel, Mary J.; Adazu, Kubaje; Obor, David; Sewe, Maquins; Vulule, John; Williamson, John M.; Slutsker, Laurence; Feikin, Daniel R.; Laserson, Kayla F.

2011-01-01

We report and explore changes in child mortality in a rural area of Kenya during 2003–2009, when major public health interventions were scaled-up. Mortality ratios and rates were calculated by using the Kenya Medical Research Institute/Centers for Disease Control and Prevention Demographic Surveillance System. Inpatient and outpatient morbidity and mortality, and verbal autopsy data were analyzed. Mortality ratios for children less than five years of age decreased from 241 to 137 deaths/1,000 live-births in 2003 and 2007 respectively. In 2008, they increased to 212 deaths/1,000 live-births. Mortality remained elevated during the first 8 months of 2009 compared with 2006 and 2007. Malaria and/or anemia accounted for the greatest increases in child mortality. Stock-outs of essential antimalarial drugs during a time of increased malaria transmission and disruption of services during civil unrest may have contributed to increased mortality in 2008–2009. To maintain gains in child survival, implementation of good policies and effective interventions must be complemented by reliable supply and access to clinical services and essential drugs. PMID:21976557

Costs and cost-effectiveness of a mobile phone text-message reminder programmes to improve health workers' adherence to malaria guidelines in Kenya.

PubMed

Zurovac, Dejan; Larson, Bruce A; Sudoi, Raymond K; Snow, Robert W

2012-01-01

Simple interventions for improving health workers' adherence to malaria case-management guidelines are urgently required across Africa. A recent trial in Kenya showed that text-message reminders sent to health workers' mobile phones improved management of pediatric outpatients by 25 percentage points. In this paper we examine costs and cost-effectiveness of this intervention. We evaluate costs and cost-effectiveness in 2010 USD under three implementation scenarios: (1) as implemented under study conditions in study areas; (2) if the intervention was routinely implemented by the Ministry of Health (MoH) in the same areas; and (3) if the intervention was scaled up nationally. Under study conditions, intervention costs were 19,342 USD, of which 45% were for developing and pretesting text-messages, 12% for developing text-message distribution system, 29% for collecting health workers' phone numbers, and 13% were costs of sending text-messages and monitoring of the system. If the intervention was implemented in the same areas by the MoH, the costs would be 28% lower (13,920 USD) due to lower costs of collecting health workers' numbers. The cost of national scale-up would be 97,350 USD, and the majority of these costs (66%) would be for sending text-messages. The cost per additional child correctly managed was 0.50 USD under study conditions, 0.36 USD if implemented by the MoH in the same area, and estimated at only 0.03 USD if implemented nationally. Even if the effect size was only 5% or the cost on the national scale was 400% higher than estimated, the cost per additional child correctly managed would be only 0.16 USD. A simple text-messaging intervention improving health worker adherence to malaria guidelines is effective and inexpensive. Further research is justified to optimize delivery of the intervention and expand targets beyond children and malaria disease.

Access and Use of Interventions to Prevent and Treat Malaria among Pregnant Women in Kenya and Mali: A Qualitative Study

PubMed Central

Hill, Jenny; Kayentao, Kassoum; Achieng, Florence; Diarra, Samba; Dellicour, Stephanie; Diawara, Sory I.; Hamel, Mary J.; Ouma, Peter; Desai, Meghna; Doumbo, Ogobara K.; ter Kuile, Feiko O.; Webster, Jayne

2015-01-01

Background Coverage of malaria in pregnancy interventions in sub-Saharan Africa is suboptimal. We undertook a systematic examination of the operational, socio-economic and cultural constraints to pregnant women’s access to intermittent preventive treatment (IPTp), long-lasting insecticide-treated nets (LLINs) and case management in Kenya and Mali to provide empirical evidence for strategies to improve coverage. Methods Focus group discussions (FGDs) were held as part of a programme of research to explore the delivery, access and use of interventions to control malaria in pregnancy. FGDs were held with four sub-groups: non-pregnant women of child bearing age (aged 15–49 years), pregnant women or mothers of children aged <1 year, adolescent women, and men. Content analysis was used to develop themes and sub-themes from the data. Results Women and men’s perceptions of the benefits of antenatal care were generally positive; motivation among women consisted of maintaining a healthy pregnancy, disease prevention in mother and foetus, checking the position of the baby in preparation for delivery, and ensuring admission to a facility in case of complications. Barriers to accessing care related to the quality of the health provider-client interaction, perceived health provider skills and malpractice, drug availability, and cost of services. Pregnant women perceived themselves and their babies at particular risk from malaria, and valued diagnosis and treatment from a health professional, but cost of treatment at health facilities drove women to use herbal remedies or drugs bought from shops. Women lacked information on the safety, efficacy and side effects of antimalarial use in pregnancy. Conclusion Women in these settings appreciated the benefits of antenatal care and yet health services in both countries are losing women to follow-up due to factors that can be improved with greater political will. Antenatal services need to be patient-centred, free-of-charge or

Does anti-malarial drug knowledge predict anti-malarial dispensing practice in drug outlets? A survey of medicine retailers in western Kenya

PubMed Central

2012-01-01

Background Malaria is a major cause of morbidity and mortality in Kenya, where it is the fifth leading cause of death in both children and adults. Effectively managing malaria is dependent upon appropriate treatment. In Kenya, between 17 to 83 percent of febrile individuals first seek treatment for febrile illness over the counter from medicine retailers. Understanding medicine retailer knowledge and behaviour in treating suspected malaria and dispensing anti-malarials is crucial. Methods To investigate medicine retailer knowledge about anti-malarials and their dispensing practices, a survey was conducted of all retail drug outlets that sell anti-malarial medications and serve residents of the Webuye Health and Demographic Surveillance Site in the Bungoma East District of western Kenya. Results Most of the medicine retailers surveyed (65%) were able to identify artemether-lumefantrine (AL) as the Kenyan Ministry of Health recommended first-line anti-malarial therapy for uncomplicated malaria. Retailers who correctly identified this treatment were also more likely to recommend AL to adult and paediatric customers. However, the proportion of medicine retailers who recommend the correct treatment is disappointingly low. Only 48% would recommend AL to adults, and 37% would recommend it to children. It was discovered that customer demand has an influence on retailer behaviour. Retailer training and education were found to be correlated with anti-malarial drug knowledge, which in turn is correlated with dispensing practices. Medicine retailer behaviour, including patient referral practice and dispensing practices, are also correlated with knowledge of the first-line anti-malarial medication. The Kenya Ministry of Health guidelines were found to influence retailer drug stocking and dispensing behaviours. Conclusion Most medicine retailers could identify the recommended first-line treatment for uncomplicated malaria, but the percentage that could not is still too high

Dynamic malaria hotspots in an open cohort in western Kenya.

PubMed

Platt, Alyssa; Obala, Andrew A; MacIntyre, Charlie; Otsyula, Barasa; Meara, Wendy Prudhomme O'

2018-01-12

Malaria hotspots, defined as areas where transmission intensity exceeds the average level, become more pronounced as transmission declines. Targeting hotspots may accelerate reductions in transmission and could be pivotal for malaria elimination. Determinants of hotspot location, particularly of their movement, are poorly understood. We used spatial statistical methods to identify foci of incidence of self-reported malaria in a large census population of 64,000 people, in 8,290 compounds over a 2.5-year study period. Regression models examine stability of hotspots and identify static and dynamic correlates with their location. Hotspot location changed over short time-periods, rarely recurring in the same area. Hotspots identified in spring versus fall season differed in their stability. Households located in a hotspot in the fall were more likely to be located in a hotspot the following fall (RR = 1.77, 95% CI: 1.66-1.89), but the opposite was true for compounds in spring hotspots (RR = 0.15, 95% CI: 0.08-0.28). Location within a hotspot was related to environmental and static household characteristics such as distance to roads or rivers. Human migration into a household was correlated with risk of hotspot membership, but the direction of the association differed based on the origin of the migration event.

Global funding trends for malaria research in sub-Saharan Africa: a systematic analysis.

PubMed

Head, Michael G; Goss, Sian; Gelister, Yann; Alegana, Victor; Brown, Rebecca J; Clarke, Stuart C; Fitchett, Joseph R A; Atun, Rifat; Scott, J Anthony G; Newell, Marie-Louise; Padmadas, Sabu S; Tatem, Andrew J

2017-08-01

Total domestic and international funding for malaria is inadequate to achieve WHO global targets in burden reduction by 2030. We describe the trends of investments in malaria-related research in sub-Saharan Africa and compare investment with national disease burden to identify areas of funding strength and potentially neglected populations. We also considered funding for malaria control. Research funding data related to malaria for 1997-2013 were sourced from existing datasets, from 13 major public and philanthropic global health funders, and from funding databases. Investments (reported in US$) were considered by geographical area and compared with data on parasite prevalence and populations at risk in sub-Saharan Africa. 45 sub-Saharan African countries were ranked by amount of research funding received. We found 333 research awards totalling US$814·4 million. Public health research covered $308·1 million (37·8%) and clinical trials covered $275·2 million (33·8%). Tanzania ($107·8 million [13·2%]), Uganda ($97·9 million [12·0%]), and Kenya ($92·9 million [11·4%]) received the highest sum of research investment and the most research awards. Malawi, Tanzania, and Uganda remained highly ranked after adjusting for national gross domestic product. Countries with a reasonably high malaria burden that received little research investment or funding for malaria control included Central African Republic (ranked 40th) and Sierra Leone (ranked 35th). Congo (Brazzaville) and Guinea had reasonably high malaria mortality, yet Congo (Brazzaville) ranked 38th and Guinea ranked 25th, thus receiving little investment. Some countries receive reasonably large investments in malaria-related research (Tanzania, Kenya, Uganda), whereas others receive little or no investments (Sierra Leone, Central African Republic). Research investments are typically highest in countries where funding for malaria control is also high. Investment strategies should consider more equitable

Malaria hotspots defined by clinical malaria, asymptomatic carriage, PCR and vector numbers in a low transmission area on the Kenyan Coast.

PubMed

Kangoye, David Tiga; Noor, Abdisalan; Midega, Janet; Mwongeli, Joyce; Mkabili, Dora; Mogeni, Polycarp; Kerubo, Christine; Akoo, Pauline; Mwangangi, Joseph; Drakeley, Chris; Marsh, Kevin; Bejon, Philip; Njuguna, Patricia

2016-04-14

Targeted malaria control interventions are expected to be cost-effective. Clinical, parasitological and serological markers of malaria transmission have been used to detect malaria transmission hotspots, but few studies have examined the relationship between the different potential markers in low transmission areas. The present study reports on the relationships between clinical, parasitological, serological and entomological markers of malaria transmission in an area of low transmission intensity in Coastal Kenya. Longitudinal data collected from 831 children aged 5-17 months, cross-sectional survey data from 800 older children and adults, and entomological survey data collected in Ganze on the Kenyan Coast were used in the present study. The spatial scan statistic test used to detect malaria transmission hotspots was based on incidence of clinical malaria episodes, prevalence of asymptomatic asexual parasites carriage detected by microscopy and polymerase chain reaction (PCR), seroprevalence of antibodies to two Plasmodium falciparum merozoite antigens (AMA1 and MSP1-19) and densities of Anopheles mosquitoes in CDC light-trap catches. There was considerable overlapping of hotspots by these different markers, but only weak to moderate correlation between parasitological and serological markers. PCR prevalence and seroprevalence of antibodies to AMA1 or MSP1-19 appeared to be more sensitive markers of hotspots at very low transmission intensity. These findings may support the choice of either serology or PCR as markers in the detection of malaria transmission hotspots for targeted interventions.

"Even if you know everything you can forget": health worker perceptions of mobile phone text-messaging to improve malaria case-management in Kenya.

PubMed

Jones, Caroline O H; Wasunna, Beatrice; Sudoi, Raymond; Githinji, Sophie; Snow, Robert W; Zurovac, Dejan

2012-01-01

This paper presents the results of a qualitative study to investigate the perceptions and experiences of health workers involved in a a cluster-randomized controlled trial of a novel intervention to improve health worker malaria case-management in 107 government health facilities in Kenya. The intervention involved sending text-messages about paediatric outpatient malaria case-management accompanied by "motivating" quotes to health workers' mobile phones. Ten malaria messages were developed reflecting recommendations from the Kenyan national guidelines. Two messages were delivered per day for 5 working days and the process was repeated for 26 weeks (May to October 2009). The accompanying quotes were unique to each message. The intervention was delivered to 119 health workers and there were significant improvements in correct artemether-lumefantrine (AL) management both immediately after the intervention (November 2009) and 6 months later (May 2010). In-depth interviews with 24 health workers were undertaken to investigate the possible drivers of this change. The results suggest high acceptance of all components of the intervention, with the active delivery of information in an on the job setting, the ready availability of new and stored text messages and the perception of being kept 'up to date' as important factors influencing practice. Applying the construct of stages of change we infer that in this intervention the SMS messages were operating primarily at the action and maintenance stages of behaviour change achieving their effect by creating an enabling environment and providing a prompt to action for the implementation of case management practices that had already been accepted as the clinical norm by the health workers. Future trials testing the effectiveness of SMS reminders in creating an enabling environment for the establishment of new norms in clinical practice as well as in providing a prompt to action for the implementation of the new case

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

Landscape determinants and remote sensing of anopheline mosquito larval habitats in the western Kenya highlands.

PubMed

Mushinzimana, Emmanuel; Munga, Stephen; Minakawa, Noboru; Li, Li; Feng, Chen-Chieng; Bian, Ling; Kitron, Uriel; Schmidt, Cindy; Beck, Louisa; Zhou, Guofa; Githeko, Andrew K; Yan, Guiyun

2006-02-16

In the past two decades the east African highlands have experienced several major malaria epidemics. Currently there is a renewed interest in exploring the possibility of anopheline larval control through environmental management or larvicide as an additional means of reducing malaria transmission in Africa. This study examined the landscape determinants of anopheline mosquito larval habitats and usefulness of remote sensing in identifying these habitats in western Kenya highlands. Panchromatic aerial photos, Ikonos and Landsat Thematic Mapper 7 satellite images were acquired for a study area in Kakamega, western Kenya. Supervised classification of land-use and land-cover and visual identification of aquatic habitats were conducted. Ground survey of all aquatic habitats was conducted in the dry and rainy seasons in 2003. All habitats positive for anopheline larvae were identified. The retrieved data from the remote sensors were compared to the ground results on aquatic habitats and land-use. The probability of finding aquatic habitats and habitats with Anopheles larvae were modelled based on the digital elevation model and land-use types. The misclassification rate of land-cover types was 10.8% based on Ikonos imagery, 22.6% for panchromatic aerial photos and 39.2% for Landsat TM 7 imagery. The Ikonos image identified 40.6% of aquatic habitats, aerial photos identified 10.6%, and Landsate TM 7 image identified 0%. Computer models based on topographic features and land-cover information obtained from the Ikonos image yielded a misclassification rate of 20.3-22.7% for aquatic habitats, and 18.1-25.1% for anopheline-positive larval habitats. One-metre spatial resolution Ikonos images combined with computer modelling based on topographic land-cover features are useful tools for identification of anopheline larval habitats, and they can be used to assist to malaria vector control in western Kenya highlands.

Discovery of the Meanings, Expressions, and Practices Related to Malaria Care Among the Maasai.

PubMed

Strang, Cecily W; Mixer, Sandra J

2016-07-01

Although malaria is preventable and treatable, morbidity and mortality from this disease continue among the Maasai of Southern Kenya. Prior to this study, the Maasai's generic and professional malaria care/cure practices were largely unknown. The purpose of this study was to discover, describe, and systematically analyze meanings, expressions, and practices that promote culturally congruent malaria care among this population. The qualitative, ethnonursing research method was used to conduct in-depth examination of the Maasai ethnohistory and culture relevant to malaria care and analyze data from 48 interviews conducted in Maasailand. Guided by the "culture care theory," four themes were discovered related to Maasai community, traditional, spiritual, and professional care/cure practices. These significant findings filled a research gap and contribute to nursing knowledge and caring practice. These study findings have implications for culturally congruent malaria care education, practice, research, policy, and partnership with traditional and professional caregivers. © The Author(s) 2015.

Mosquito larval source management for controlling malaria

PubMed Central

Tusting, Lucy S; Thwing, Julie; Sinclair, David; Fillinger, Ulrike; Gimnig, John; Bonner, Kimberly E; Bottomley, Christian; Lindsay, Steven W

2015-01-01

. Main results We included 13 studies; four cluster-RCTs, eight controlled before-and-after trials, and one randomized cross-over trial. The included studies evaluated habitat modification (one study), habitat modification with larviciding (two studies), habitat manipulation (one study), habitat manipulation plus larviciding (two studies), or larviciding alone (seven studies) in a wide variety of habitats and countries. Malaria incidence In two cluster-RCTs undertaken in Sri Lanka, larviciding of abandoned mines, streams, irrigation ditches, and rice paddies reduced malaria incidence by around three-quarters compared to the control (RR 0.26, 95% CI 0.22 to 0.31, 20,124 participants, two trials, moderate quality evidence). In three controlled before-and-after trials in urban and rural India and rural Kenya, results were inconsistent (98,233 participants, three trials, very low quality evidence). In one trial in urban India, the removal of domestic water containers together with weekly larviciding of canals and stagnant pools reduced malaria incidence by three quarters. In one trial in rural India and one trial in rural Kenya, malaria incidence was higher at baseline in intervention areas than in controls. However dam construction in India, and larviciding of streams and swamps in Kenya, reduced malaria incidence to levels similar to the control areas. In one additional randomized cross-over trial in the flood plains of the Gambia River, where larval habitats were extensive and ill-defined, larviciding by ground teams did not result in a statistically significant reduction in malaria incidence (2039 participants, one trial). Parasite prevalence In one cluster-RCT from Sri Lanka, larviciding reduced parasite prevalence by almost 90% (RR 0.11, 95% CI 0.05 to 0.22, 2963 participants, one trial, moderate quality evidence). In five controlled before-and-after trials in Greece, India, the Philippines, and Tanzania, LSM resulted in an average reduction in parasite prevalence of

“Even if You Know Everything You Can Forget”: Health Worker Perceptions of Mobile Phone Text-Messaging to Improve Malaria Case-Management in Kenya

PubMed Central

Jones, Caroline O. H.; Wasunna, Beatrice; Sudoi, Raymond; Githinji, Sophie; Snow, Robert W.; Zurovac, Dejan

2012-01-01

This paper presents the results of a qualitative study to investigate the perceptions and experiences of health workers involved in a a cluster-randomized controlled trial of a novel intervention to improve health worker malaria case-management in 107 government health facilities in Kenya. The intervention involved sending text-messages about paediatric outpatient malaria case-management accompanied by “motivating” quotes to health workers’ mobile phones. Ten malaria messages were developed reflecting recommendations from the Kenyan national guidelines. Two messages were delivered per day for 5 working days and the process was repeated for 26 weeks (May to October 2009). The accompanying quotes were unique to each message. The intervention was delivered to 119 health workers and there were significant improvements in correct artemether-lumefantrine (AL) management both immediately after the intervention (November 2009) and 6 months later (May 2010). In-depth interviews with 24 health workers were undertaken to investigate the possible drivers of this change. The results suggest high acceptance of all components of the intervention, with the active delivery of information in an on the job setting, the ready availability of new and stored text messages and the perception of being kept ‘up to date’ as important factors influencing practice. Applying the construct of stages of change we infer that in this intervention the SMS messages were operating primarily at the action and maintenance stages of behaviour change achieving their effect by creating an enabling environment and providing a prompt to action for the implementation of case management practices that had already been accepted as the clinical norm by the health workers. Future trials testing the effectiveness of SMS reminders in creating an enabling environment for the establishment of new norms in clinical practice as well as in providing a prompt to action for the implementation of the new case

Progress towards understanding the ecology and epidemiology of malaria in the western Kenya highlands: opportunities and challenges for control under climate change risk.

PubMed

Githeko, A K; Ototo, E N; Guiyun, Yan

2012-01-01

Following severe malaria epidemics in the western Kenya highlands after the late 1980s it became imperative to undertake eco-epidemiological assessments of the disease and determine its drivers, spatial-temporal distribution and control strategies. Extensive research has indicated that the major biophysical drivers of the disease are climate change and variability, terrain, topography, hydrology and immunity. Vector distribution is focalized at valley bottoms and abundance is closely related with drainage efficiency, habitat availability, stability and productivity of the ecosystems. Early epidemic prediction models have been developed and they can be used to assess climate risks that warrant extra interventions with a lead time of 2-4 months. Targeted integrated vector management strategies can significantly reduce the cost on the indoor residual spraying by targeting the foci of transmission in transmission hotspots. Malaria control in the highlands has reduced vector population by 90%, infections by 50-90% in humans and in some cases transmission has been interrupted. Insecticide resistance is increasing and as transmission decreases so will immunity. Active surveillance will be required to monitor and contain emerging threats. More studies on eco-stratification of the disease, based on its major drivers, are required so that interventions are tailored for specific ecosystems. New and innovative control interventions such as house modification with a one-application strategy may reduce the threat from insecticide resistance and low compliance associated with the use of ITNs. Copyright © 2011 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.

Treatment-seeking patterns for malaria in pharmacies in five sub-Saharan African countries.

PubMed

Ladner, Joël; Davis, Ben; Audureau, Etienne; Saba, Joseph

2017-08-29

Artemisinin-based combination therapy (ACT) is recommended as the first-line anti-malarial treatment strategy in sub-Saharan African countries. WHO policy recommends parasitological confirmation by microscopy or rapid diagnostic test (RDT) in all cases of suspected malaria prior to treatment. Gaps remain in understanding the factors that influence patient treatment-seeking behaviour and anti-malarial drug purchase decisions in the private sector. The objective of this study was to identify patient treatment-seeking behaviour in Ghana, Kenya, Nigeria, Tanzania, and Uganda. Face-to-face patient interviews were conducted at a total of 208 randomly selected retail outlets in five countries. At each outlet, exit interviews were conducted with five patients who indicated they had come seeking anti-malarial treatment. The questionnaire was anonymous and standardized in the five countries and collected data on different factors, including socio-demographic characteristics, history of illness, diagnostic practices (i.e. microscopy or RDT), prescription practices and treatment purchase. The price paid for the treatment was also collected from the outlet vendor. A total of 994 patients were included from the five countries. Location of malaria diagnosis was significantly different in the five countries. A total of 484 blood diagnostic tests were performed, (72.3% with microscopy and 27.7% with RDT). ACTs were purchased by 72.5% of patients who had undergone blood testing and 86.5% of patients without a blood test, regardless of whether the test result was positive or negative (p < 10 -4 ). A total of 531 patients (53.4%) had an anti-malarial drug prescription, of which 82.9% were prescriptions for an ACT. There were significant differences in prescriptions by country. A total of 923 patients (92.9%) purchased anti-malarial drugs in an outlet, including 79.1% of patients purchasing an ACT drug: 98.0% in Ghana, 90.5% in Kenya, 80.4% in Nigeria, 69.2% in Tanzania, and 57.7% in

Development of behaviour change communication strategy for a vaccination-linked malaria control tool in southern Tanzania.

PubMed

Mushi, Adiel K; Schellenberg, Joanna; Mrisho, Mwifadhi; Manzi, Fatuma; Mbuya, Conrad; Mponda, Haji; Mshinda, Hassan; Tanner, Marcel; Alonso, Pedro; Pool, Robert; Schellenberg, David

2008-09-29

Intermittent preventive treatment of malaria in infants (IPTi) using sulphadoxine-pyrimethamine and linked to the expanded programme on immunization (EPI) is a promising strategy for malaria control in young children. As evidence grows on the efficacy of IPTi as public health strategy, information is needed so that this novel control tool can be put into practice promptly, once a policy recommendation is made to implement it. This paper describes the development of a behaviour change communication strategy to support implementation of IPTi by the routine health services in southern Tanzania, in the context of a five-year research programme evaluating the community effectiveness of IPTi. Mixed methods including a rapid qualitative assessment and quantitative health facility survey were used to investigate communities' and providers' knowledge and practices relating to malaria, EPI, sulphadoxine-pyrimethamine and existing health posters. Results were applied to develop an appropriate behaviour change communication strategy for IPTi involving personal communication between mothers and health staff, supported by a brand name and two posters. Malaria in young children was considered to be a nuisance because it causes sleepless nights. Vaccination services were well accepted and their use was considered the mother's responsibility. Babies were generally taken for vaccination despite complaints about fevers and swellings after the injections. Sulphadoxine-pyrimethamine was widely used for malaria treatment and intermittent preventive treatment of malaria in pregnancy, despite widespread rumours of adverse reactions based on hearsay and newspaper reports. Almost all health providers said that they or their spouse were ready to take SP in pregnancy (96%, 223/242). A brand name, key messages and images were developed and pre-tested as behaviour change communication materials. The posters contained public health messages, which explained the intervention itself, how and when

Determinants of Primary School Non-Enrollment and Absenteeism: Results from a Retrospective, Convergent Mixed Methods, Cohort Study in Rural Western Kenya

PubMed Central

King, Nia; Dewey, Cate; Borish, David

2015-01-01

Background Education is a key element in the socioeconomic development required to improve quality of life in Kenya. Despite the introduction of free primary education, primary school enrollment and attendance levels remain low. Drawing on qualitative and quantitative data, this study explores the determinants of non-enrollment and absenteeism in rural western Kenya and potential mitigation strategies to address these issues. Methods The study was conducted in Bwaliro village in rural western Kenya. A random sample of 64 students was obtained by blocking the village primary school’s student population according to grade level, gender, and orphan status. Qualitative and quantitative data were collected through interviews with parents, guardians, and key informants, and focus group discussions with students. Quantitative data were compared using chi-square tests, Student’s T-test, and Poisson regressions. Qualitative data were analyzed using thematic content analysis. Results Malaria, menstruation, and lack of money were among the most notable determinants of primary school dropout and absenteeism, and these factors disproportionately impacted orphans and female students. Potential mitigation strategies suggested by the community included provision of malaria treatment or prevention, reduction in education costs, expansion of the established school-feeding program, and provision of sanitary pads. Conclusion Despite free primary education, numerous factors continue to prevent children in rural western Kenya from attending primary school. The findings suggest that interventions should primarily target orphaned and female students. Prior to implementation, suggested mitigation strategies should be assessed for cost-effectiveness. PMID:26371885

"Every day they keep adding new tools but they don't take any away": Producing indicators for intermittent preventive treatment for malaria in pregnancy (IPTp) from routine data in Kenya.

PubMed

Okello, George; Gerrets, Rene; Zakayo, Scholastica; Molyneux, Sassy; Jones, Caroline

2018-01-01

Intermittent preventive treatment for malaria in pregnancy (IPTp) is part of a multi-pronged strategy aimed at preventing malaria in pregnancy in areas of moderate to high transmission in sub-Saharan Africa. Despite being formally adopted as a malaria prevention policy over a decade ago, IPTp coverage has remained low. Recent demands for action have incorporated calls to strengthen IPTp monitoring and evaluation systems, including the use of routine data, to measure coverage, track implementation and identify roadblocks to improving uptake. Concerns about the quality of malaria indicators reported through routine information systems are well recognized, but there are few data on the realities of IPTp recording practices in frontline facilities or their entry into District Health Information Software (DHIS2). Drawing on fieldwork conducted in two malaria endemic sub-counties in Kenya, we explore how local adaptations and innovations employed by health workers and sub-country managers to cope with a range of health system constraints, shape recording practices and in turn, the measurement of IPTp. Data were collected through observations, interviews, and document reviews. Data analysis and interpretation was guided by thematic analysis approach. Measurement of IPTp was undermined by health system constraints such as stock-out of drugs and human resource shortages. Coping strategies adopted by health workers to address these challenges ensured continuity in service delivery and IPTp data generation but had variable consequences on IPTp data quality. Unclear recording and reporting instructions also led to lack of standardization in IPTp data generation. The use of redundant tools created significant data burdens which undermined service delivery in general. There is need to integrate monthly reporting forms so as to remove redundancies which exacerbates workload for health workers and disrupts service delivery. Similarly, data collection instructions in registers and

Perceptions of symptoms of severe childhood malaria among Mijikenda and Luo residents of coastal Kenya.

PubMed

Mwenesi, H A; Harpham, T; Marsh, K; Snow, R W

1995-04-01

Effective community based malaria control programmes require an understanding of current perceptions of malaria as a disease and its severe manifestations. Quantitative and qualitative surveys of mothers on the Kenyan Coast suggest that fever is conceptualised in biomedical terms whereas the aetiology of severe malaria is perceived to be of more complex cultural origin. This is reflected in the treatments sought for convulsions. The results are discussed in the context of ethnographic factors. To be effective, future health information programmes must take cultural beliefs into account.

Toll-like receptor polymorphisms in malaria-endemic populations

PubMed Central

Greene, Jennifer A; Moormann, Ann M; Vulule, John; Bockarie, Moses J; Zimmerman, Peter A; Kazura, James W

2009-01-01

Background Toll-like receptors (TLR) and related downstream signaling pathways of innate immunity have been implicated in the pathogenesis of Plasmodium falciparum malaria. Because of their potential role in malaria pathogenesis, polymorphisms in these genes may be under selective pressure in populations where this infectious disease is endemic. Methods A post-PCR Ligation Detection Reaction-Fluorescent Microsphere Assay (LDR-FMA) was developed to determine the frequencies of TLR2, TLR4, TLR9, MyD88-Adaptor Like Protein (MAL) single nucleotide polymorphisms (SNPs), and TLR2 length polymorphisms in 170 residents of two regions of Kenya where malaria transmission is stable and high (holoendemic) or episodic and low, 346 residents of a malaria holoendemic region of Papua New Guinea, and 261 residents of North America of self-identified ethnicity. Results The difference in historical malaria exposure between the two Kenyan sites has significantly increased the frequency of malaria protective alleles glucose-6-phoshpate dehydrogenase (G6PD) and Hemoglobin S (HbS) in the holoendemic site compared to the episodic transmission site. However, this study detected no such difference in the TLR2, TLR4, TLR9, and MAL allele frequencies between the two study sites. All polymorphisms were in Hardy Weinberg Equilibrium in the Kenyan and Papua New Guinean populations. TLR9 SNPs and length polymorphisms within the TLR2 5' untranslated region were the only mutant alleles present at a frequency greater than 10% in all populations. Conclusion Similar frequencies of TLR2, TLR4, TLR9, and MAL genetic polymorphisms in populations with different histories of malaria exposure suggest that these innate immune pathways have not been under strong selective pressure by malaria. Genotype frequencies are consistent with Hardy-Weinberg Equilibrium and the Neutral Theory, suggesting that genetic drift has influenced allele frequencies to a greater extent than selective pressure from malaria or any

Quantifying cross-border movements and migrations for guiding the strategic planning of malaria control and elimination

PubMed Central

2014-01-01

Background Identifying human and malaria parasite movements is important for control planning across all transmission intensities. Imported infections can reintroduce infections into areas previously free of infection, maintain ‘hotspots’ of transmission and import drug resistant strains, challenging national control programmes at a variety of temporal and spatial scales. Recent analyses based on mobile phone usage data have provided valuable insights into population and likely parasite movements within countries, but these data are restricted to sub-national analyses, leaving important cross-border movements neglected. Methods National census data were used to analyse and model cross-border migration and movement, using East Africa as an example. ‘Hotspots’ of origin-specific immigrants from neighbouring countries were identified for Kenya, Tanzania and Uganda. Populations of origin-specific migrants were compared to distance from origin country borders and population size at destination, and regression models were developed to quantify and compare differences in migration patterns. Migration data were then combined with existing spatially-referenced malaria data to compare the relative propensity for cross-border malaria movement in the region. Results The spatial patterns and processes for immigration were different between each origin and destination country pair. Hotspots of immigration, for example, were concentrated close to origin country borders for most immigrants to Tanzania, but for Kenya, a similar pattern was only seen for Tanzanian and Ugandan immigrants. Regression model fits also differed between specific migrant groups, with some migration patterns more dependent on population size at destination and distance travelled than others. With these differences between immigration patterns and processes, and heterogeneous transmission risk in East Africa and the surrounding region, propensities to import malaria infections also likely show

A public-private partnership for malaria control: lessons from the Malarone Donation Programme.

PubMed Central

Oyediran, A. B. O. Olukayode; Ddumba, Edward M.; Ochola, Samuel A.; Lucas, Adetokunbo O.; Koporc, Kim; Dowdle, Walter R.

2002-01-01

In 1996, Glaxo Wellcome offered to donate up to a million treatment courses annually of Malarone, a new antimalarial, with a view to reducing the global burden of malaria. The Malarone Donation Programme (MDP) was established the following year. Eight pilot sites were selected in Kenya and Uganda to develop and evaluate an effective, locally sustainable donation strategy that ensured controlled and appropriate use of Malarone. The pilot programme targeted individuals who had acute uncomplicated Plasmodium falciparum malaria that had not responded to first-line treatments with chloroquine or sulfadoxine-pyrimethamine. Of the 161 079 patients clinically diagnosed at the pilot sites as having malaria, 1101 (0.68%) met all the conditions for participation and received directly observed treatment with Malarone. MDP had a positive effect at the pilot sites by improving the diagnosis and management of malaria. However, the provision of Malarone as a second-line drug at the district hospital level was not an efficient and effective use of resources. The number of deaths among children and adults ineligible for MDP at the pilot sites suggested that high priority should be given to meeting the challenges of malaria treatment at the community level. PMID:12471403

Capacity and readiness of civil society organisations to implement community case management of malaria in Kenya.

PubMed

Marita, Enock; Oule, Jared; Mungai, Margaret; Thiam, Sylla; Ilako, Festus

2016-01-01

Civil Society Organizations (CSOs) contribute to achieving development goals through advocacy, social mobilisation and provision of health services. CSO programming is a key component of Global Fund (GF) grants; however, CSOs face technical and governance capacity challenges in grant utilisation leading to missed opportunities for improving health at community level. Amref Health Africa was appointed Principal Recipient of a GF grant aimed at scaling up community case management of malaria through CSOs as sub-recipients in western Kenya. To identify potential risks and strengthen grant management, Amref Health Africa and the Ministry of Health conducted a capacity needs assessment to determine the capacity of CSOs to effectively utilise grants. 26 selected CSOs participated in this study. Document reviews and on-site assessments and observations were conducted using structured tool. The five main assessment areas were: governance and risk management; strategic and operational planning; monitoring and evaluation; programme management; and financial management. Overall performance was grouped into four categories: 3.0-2.5 (excellent), 2.0-2.4 (good), 1.5-1.9 (fair), and 1.0-1.4 (poor). Data were collected and analysed using Excel software. Twenty five out of 26 CSOs were legally compliant. 14(54%) CSOs were categorized as good; 7(27%) as excellent; 3(12%) as poor and 2(8%) as fair. Most CSOs had good programme management capacity but monitoring and evaluation presented the most capacity gaps. More than 75% of the CSOs were rated as excellent or good. A capacity building plan, programme risk management plan and oversight mechanisms were important for successful grant implementation.

Volatile biomarkers of symptomatic and asymptomatic malaria infection in humans

PubMed Central

Wanjiku, Caroline; Stanczyk, Nina M.; Pulido, Hannier; Betz, Heike S.

2018-01-01

Malaria remains among the world’s deadliest diseases, and control efforts depend critically on the availability of effective diagnostic tools, particularly for the identification of asymptomatic infections, which play a key role in disease persistence and may account for most instances of transmission but often evade detection by current screening methods. Research on humans and in animal models has shown that infection by malaria parasites elicits changes in host odors that influence vector attraction, suggesting that such changes might yield robust biomarkers of infection status. Here we present findings based on extensive collections of skin volatiles from human populations with high rates of malaria infection in Kenya. We report broad and consistent effects of malaria infection on human volatile profiles, as well as significant divergence in the effects of symptomatic and asymptomatic infections. Furthermore, predictive models based on machine learning algorithms reliably determined infection status based on volatile biomarkers. Critically, our models identified asymptomatic infections with 100% sensitivity, even in the case of low-level infections not detectable by microscopy, far exceeding the performance of currently available rapid diagnostic tests in this regard. We also identified a set of individual compounds that emerged as consistently important predictors of infection status. These findings suggest that volatile biomarkers may have significant potential for the development of a robust, noninvasive screening method for detecting malaria infections under field conditions. PMID:29760095

A cost analysis of the employer-based bednet programme in Coastal and Western Kenya.

PubMed

Ngugi, Isaac K; Chiguzo, Athuman N; Guyatt, Helen L

2004-03-01

Malaria remains a major health problem in Africa. One preventative strategy currently advocated is the use of bednets, preferably treated with insecticide. Many approaches to bednet delivery have been adopted in Kenya, including an employer-based malaria control strategy (EBMC). The cost and sustainability of this approach have not previously been assessed. This paper presents the financial cost (cash expenditure) of the EBMC programme implemented in the Coastal and Western regions of Kenya by the African Medical and Research Foundation (AMREF) between April 1998 and February 2002. Getting a bednet and insecticide to an employee was estimated to cost the provider US$15.8. This could be reduced by US$0.5 if the remaining stocks were liquidated and by an additional US$1.3 if the salvage of capital items is considered. The venture of distributing bednets to employees through the programme proved lucrative to organized community groups (OCGs), for they made between 24 and 29% gross profit from the nets they sold. Consequently, OCGs in nine of the 13 companies involved had retained enough funds from which they could buy and sell bednets without further donor financial support, and this portrays some elements of a sustainable supply system.

The role of vitamin D in malaria.

PubMed

Lương, Khanh Vinh Quốc; Nguyễn, Lan Thi Hoàng

2015-01-15

An abnormal calcium-parathyroid hormone (PTH)-vitamin D axis has been reported in patients with malaria infection. A role for vitamin D in malaria has been suggested by many studies. Genetic studies have identified numerous factors that link vitamin D to malaria, including human leukocyte antigen genes, toll-like receptors, heme oxygenase-1, angiopoietin-2, cytotoxic T lymphocyte antigen-4, nucleotide-binding oligomerization domain-like receptors, and Bcl-2. Vitamin D has also been implicated in malaria via its effects on the Bacillus Calmette-Guerin (BCG) vaccine, matrix metalloproteinases, mitogen-activated protein kinase pathways, prostaglandins, reactive oxidative species, and nitric oxide synthase. Vitamin D may be important in malaria; therefore, additional research on its role in malaria is needed.

Cost analysis of school-based intermittent screening and treatment of malaria in Kenya

PubMed Central

2011-01-01

Background The control of malaria in schools is receiving increasing attention, but there remains currently no consensus as to the optimal intervention strategy. This paper analyses the costs of intermittent screening and treatment (IST) of malaria in schools, implemented as part of a cluster-randomized controlled trial on the Kenyan coast. Methods Financial and economic costs were estimated using an ingredients approach whereby all resources required in the delivery of IST are quantified and valued. Sensitivity analysis was conducted to investigate how programme variation affects costs and to identify potential cost savings in the future implementation of IST. Results The estimated financial cost of IST per child screened is US$ 6.61 (economic cost US$ 6.24). Key contributors to cost were salary costs (36%) and malaria rapid diagnostic tests (RDT) (22%). Almost half (47%) of the intervention cost comprises redeployment of existing resources including health worker time and use of hospital vehicles. Sensitivity analysis identified changes to intervention delivery that can reduce programme costs by 40%, including use of alternative RDTs and removal of supervised treatment. Cost-effectiveness is also likely to be highly sensitive to the proportion of children found to be RDT-positive. Conclusion In the current context, school-based IST is a relatively expensive malaria intervention, but reducing the complexity of delivery can result in considerable savings in the cost of intervention. (Costs are reported in US$ 2010). PMID:21933376

Knowledge and Adherence to the National Guidelines for Malaria Case Management in Pregnancy among Healthcare Providers and Drug Outlet Dispensers in Rural, Western Kenya

PubMed Central

Riley, Christina; Dellicour, Stephanie; Ouma, Peter; Kioko, Urbanus; ter Kuile, Feiko O.; Omar, Ahmeddin; Kariuki, Simon; Buff, Ann M.; Desai, Meghna; Gutman, Julie

2016-01-01

Background Although prompt, effective treatment is a cornerstone of malaria control, information on provider adherence to malaria in pregnancy (MIP) treatment guidelines is limited. Incorrect or sub-optimal treatment can adversely affect the mother and fetus. This study assessed provider knowledge of and adherence to national case management guidelines for uncomplicated MIP. Methods We conducted a cross-sectional study from September to November 2013, in 51 health facilities (HF) and a randomly-selected sample of 39 drug outlets (DO) in the KEMRI/CDC Health and Demographic Surveillance System area in western Kenya. Provider knowledge of national treatment guidelines was assessed with standardized questionnaires. Correct practice required adequate diagnosis, pregnancy assessment, and treatment with correct drug and dosage. In HF, we conducted exit interviews in all women of childbearing age assessed for fever. In DO, simulated clients posing as first trimester pregnant women or as relatives of third trimester pregnant women collected standardized information. Results Correct MIP case management knowledge and practice were observed in 45% and 31% of HF and 0% and 3% of DO encounters, respectively. The correct drug and dosage for pregnancy trimester was prescribed in 62% of HF and 42% of DO encounters; correct prescription occurred less often in first than in second/ third trimesters (HF: 24% vs. 65%, p<0.01; DO: 0% vs. 40%, p<0.01). Sulfadoxine-pyrimethamine, which is not recommended for malaria treatment, was prescribed in 3% of HF and 18% of DO encounters. Exposure to artemether-lumefantrine in first trimester, which is contraindicated, occurred in 29% and 49% of HF and DO encounters, respectively. Conclusion This study highlights knowledge inadequacies and incorrect prescribing practices in the treatment of MIP. Particularly concerning is the prescription of contraindicated medications in the first trimester. These issues should be addressed through comprehensive

Changing patterns of clinical malaria since 1965 among a tea estate population located in the Kenyan highlands*

PubMed Central

Shanks, G. D.; Biomndo, K.; Hay, S. I.; Snow, R. W.

2012-01-01

The changing epidemiology of clinical malaria since 1965 among hospitalized patients was studied at a group of tea estates in the western highlands of Kenya. These data indicate recent dramatic increases in the numbers of malaria admissions (6·5 to 32·5% of all admissions), case fatality (1·3 to 6%) and patients originating from low-risk, highland areas (34 to 59%). Climate change, environmental management, population migration, and breakdown in health service provision seem unlikely explanations for this changing disease pattern. The coincident arrival of chloroquine resistance during the late 1980s in the sub-region suggests that drug resistance is a key factor in the current pattern and burden of malaria among this highland population. PMID:10974991

High Sensitivity and Specificity of Clinical Microscopy in Rural Health Facilities in Western Kenya Under an External Quality Assurance Program

PubMed Central

Wafula, Rebeccah; Sang, Edna; Cheruiyot, Olympia; Aboto, Angeline; Menya, Diana; O'Meara, Wendy Prudhomme

2014-01-01

Microscopic diagnosis of malaria is a well-established and inexpensive technique that has the potential to provide accurate diagnosis of malaria infection. However, it requires both training and experience. Although it is considered the gold standard in research settings, the sensitivity and specificity of routine microscopy for clinical care in the primary care setting has been reported to be unacceptably low. We established a monthly external quality assurance program to monitor the performance of clinical microscopy in 17 rural health centers in western Kenya. The average sensitivity over the 12-month period was 96% and the average specificity was 88%. We identified specific contextual factors that contributed to inadequate performance. Maintaining high-quality malaria diagnosis in high-volume, resource-constrained health facilities is possible. PMID:24935953

Ethnopharmacological survey of Samburu district, Kenya

PubMed Central

Nanyingi, Mark O; Mbaria, James M; Lanyasunya, Adamson L; Wagate, Cyrus G; Koros, Kipsengeret B; Kaburia, Humphrey F; Munenge, Rahab W; Ogara, William O

2008-01-01

Background Ethnobotanical pharmacopoeia is confidently used in disease intervention and there is need for documentation and preservation of traditional medical knowledge to bolster the discovery of novel drugs. The objective of the present study was to document the indigenous medicinal plant utilization, management and their extinction threats in Samburu District, Kenya. Methods Field research was conducted in six divisions of Samburu District in Kenya. We randomly sampled 100 consented interviewees stratified by age, gender, occupation and level of education. We collected plant use data through semi-structured questionnaires; transect walks, oral interviews and focus groups discussions. Voucher specimens of all cited botanic species were collected and deposited at University of Nairobi's botany herbarium. Results Data on plant use from the informants yielded 990 citations on 56 medicinal plant species, which are used to treat 54 different animal and human diseases including; malaria, digestive disorders, respiratory syndromes and ectoparasites. Conclusion The ethnomedicinal use of plant species was documented in the study area for treatment of both human and veterinary diseases. The local population has high ethnobotanical knowledge and has adopted sound management conservation practices. The major threatening factors reported were anthropogenic and natural. Ethnomedical documentation and sustainable plant utilization can support drug discovery efforts in developing countries. PMID:18498665

Developing a Nursing Database System in Kenya

PubMed Central

Riley, Patricia L; Vindigni, Stephen M; Arudo, John; Waudo, Agnes N; Kamenju, Andrew; Ngoya, Japheth; Oywer, Elizabeth O; Rakuom, Chris P; Salmon, Marla E; Kelley, Maureen; Rogers, Martha; St Louis, Michael E; Marum, Lawrence H

2007-01-01

Objective To describe the development, initial findings, and implications of a national nursing workforce database system in Kenya. Principal Findings Creating a national electronic nursing workforce database provides more reliable information on nurse demographics, migration patterns, and workforce capacity. Data analyses are most useful for human resources for health (HRH) planning when workforce capacity data can be linked to worksite staffing requirements. As a result of establishing this database, the Kenya Ministry of Health has improved capability to assess its nursing workforce and document important workforce trends, such as out-migration. Current data identify the United States as the leading recipient country of Kenyan nurses. The overwhelming majority of Kenyan nurses who elect to out-migrate are among Kenya's most qualified. Conclusions The Kenya nursing database is a first step toward facilitating evidence-based decision making in HRH. This database is unique to developing countries in sub-Saharan Africa. Establishing an electronic workforce database requires long-term investment and sustained support by national and global stakeholders. PMID:17489921

"Before we used to get sick all the time": perceptions of malaria and use of long-lasting insecticide-treated bed nets (LLINs) in a rural Kenyan community

PubMed Central

2010-01-01

Background Malaria is a leading global cause of preventable morbidity and mortality, especially in sub-Saharan Africa, despite recent advances in treatment and prevention technologies. Scale-up and wide distribution of long-lasting insecticide-treated nets (LLINs) could rapidly decrease malarial disease in endemic areas, if used properly and continuously. Studies have shown that effective use of LLINs depends, in part, upon understanding causal factors associated with malaria. This study examined malaria beliefs, attitudes, and practices toward LLINs assessed during a large-scale integrated prevention campaign (IPC) in rural Kenya. Methods Qualitative interviews were conducted with 34 IPC participants who received LLINs as part of a comprehensive prevention package of goods and services. One month after distribution, interviewers asked these individuals about their attitudes and beliefs regarding malaria, and about their use of LLINs. Results Virtually all participants noted that mosquitoes were involved in causing malaria, though a substantial proportion of participants (47 percent) also mentioned an incorrect cause in addition to mosquitoes. For example, participants commonly noted that the weather (rain, cold) or consumption of bad food and water caused malaria. Regardless, most participants used the LLINs they were given and most mentioned positive benefits from their use, namely reductions in malarial illness and in the costs associated with its diagnosis and treatment. Conclusions Attitudes toward LLINs were positive in this rural community in Western Kenya, and respondents noted benefits with LLIN use. With improved understanding and clarification of the direct (mosquitoes) and indirect (e.g., standing water) causes of malaria, it is likely that LLIN use can be sustained, offering effective household-level protection against malaria. PMID:21118550

Improvement of malaria diagnostic system based on acridine orange staining.

PubMed

Kimura, Masatsugu; Teramoto, Isao; Chan, Chim W; Idris, Zulkarnain Md; Kongere, James; Kagaya, Wataru; Kawamoto, Fumihiko; Asada, Ryoko; Isozumi, Rie; Kaneko, Akira

2018-02-07

Rapid diagnosis of malaria using acridine orange (AO) staining and a light microscope with a halogen lamp and interference filter was deployed in some malaria-endemic countries. However, it has not been widely adopted because: (1) the lamp was weak as an excitation light and the set-up did not work well under unstable power supply; and, (2) the staining of samples was frequently inconsistent. The halogen lamp was replaced by a low-cost, blue light-emitting diode (LED) lamp. Using a reformulated AO solution, the staining protocol was revised to make use of a concentration gradient instead of uniform staining. To evaluate this new AO diagnostic system, a pilot field study was conducted in the Lake Victoria basin in Kenya. Without staining failure, malaria infection status of about 100 samples was determined on-site per one microscopist per day, using the improved AO diagnostic system. The improved AO diagnosis had both higher overall sensitivity (46.1 vs 38.9%: p = 0.08) and specificity (99.0 vs 96.3%) than the Giemsa method (N = 1018), using PCR diagnosis as the standard. Consistent AO staining of thin blood films and rapid evaluation of malaria parasitaemia with the revised protocol produced superior results relative to the Giemsa method. This AO diagnostic system can be set up easily at low cost using an ordinary light microscope. It may supplement rapid diagnostic tests currently used in clinical settings in malaria-endemic countries, and may be considered as an inexpensive tool for case surveillance in malaria-eliminating countries.

Malaria control in Bungoma District, Kenya: a survey of home treatment of children with fever, bednet use and attendance at antenatal clinics.

PubMed Central

Hamel, M. J.; Odhacha, A.; Roberts, J. M.; Deming, M. S.

2001-01-01

OBJECTIVE: To lay the basis for planning an improved malaria control programme in Bungoma District, Kenya. METHODS: By means of a cluster sample household survey an investigation was conducted into the home management of febrile children, the use of bednets, and attendance at antenatal clinics. FINDINGS: Female carers provided information on 314 recently febrile children under 5 years of age, of whom 43% received care at a health facility, 47% received an antimalarial drug at home, and 25% received neither. Of the antimalarial treatments given at home, 91% were started by the second day of fever and 92% were with chloroquine, the nationally recommended antimalarial at the time. The recommended dosage of chloroquine to be administered over three days was 25 mg/kg but the median chloroquine tablet or syrup dosage given over the first three days of treatment was 15 mg/kg. The total dosages ranged from 2.5 mg/kg to 82 mg/kg, administered over one to five days. The dosages were lower when syrup was administered than when tablets were used. Only 5% of children under 5 years of age slept under a bednet. No bednets had been treated with insecticide since purchase. At least two antenatal visits were made by 91% of pregnant women. CONCLUSIONS: Carers are major and prompt providers of antimalarial treatment. Home treatment practices should be strengthened and endorsed when prompt treatment at a health facility is impossible. The administration of incorrect dosages, which proved common with chloroquine, may occur less frequently with sulfadoxine-pyrimethamine, as its dosage regimen is simpler. High levels of utilization of antenatal clinics afford the opportunity to achieve good coverage with presumptive intermittent malaria treatments during pregnancy, and to reach the goal of widespread bednet use by pregnant women and children by distributing nets during antenatal clinic visits. PMID:11731808

Capacity and readiness of civil society organisations to implement community case management of malaria in Kenya

PubMed Central

Marita, Enock; Oule, Jared; Mungai, Margaret; Thiam, Sylla; Ilako, Festus

2016-01-01

Introduction Civil Society Organizations (CSOs) contribute to achieving development goals through advocacy, social mobilisation and provision of health services. CSO programming is a key component of Global Fund (GF) grants; however, CSOs face technical and governance capacity challenges in grant utilisation leading to missed opportunities for improving health at community level. Amref Health Africa was appointed Principal Recipient of a GF grant aimed at scaling up community case management of malaria through CSOs as sub-recipients in western Kenya. To identify potential risks and strengthen grant management, Amref Health Africa and the Ministry of Health conducted a capacity needs assessment to determine the capacity of CSOs to effectively utilise grants. Methods 26 selected CSOs participated in this study. Document reviews and on-site assessments and observations were conducted using structured tool. The five main assessment areas were: governance and risk management; strategic and operational planning; monitoring and evaluation; programme management; and financial management. Overall performance was grouped into four categories: 3.0-2.5 (excellent), 2.0-2.4 (good), 1.5-1.9 (fair), and 1.0-1.4 (poor). Data were collected and analysed using Excel software. Results Twenty five out of 26 CSOs were legally compliant. 14(54%) CSOs were categorized as good; 7(27%) as excellent; 3(12%) as poor and 2(8%) as fair. Most CSOs had good programme management capacity but monitoring and evaluation presented the most capacity gaps. Conclusion More than 75% of the CSOs were rated as excellent or good. A capacity building plan, programme risk management plan and oversight mechanisms were important for successful grant implementation. PMID:28523081

The process of changing national malaria treatment policy: lessons from country-level studies.

PubMed

Williams, Holly Ann; Durrheim, David; Shretta, Rima

2004-11-01

Widespread resistance of Plasmodium falciparum parasites to commonly used antimalarials, such as chloroquine, has resulted in many endemic countries considering changing their malaria treatment policy. Identifying and understanding the key influences that affect decision-making, and factors that facilitate or undermine policy implementation, is critical for improving the policy process and guiding resource allocation during this process. A historical review of archival documents from Malaŵi and data obtained from in-depth policy studies in four countries (Tanzania, South Africa, Kenya and Peru) that have changed malaria treatment policy provides important lessons about decision-making, the policy cycle and complex policy environment, while specifically identifying strategies successfully employed to facilitate policy-making and implementation. Findings from these country-level studies indicate that the process of malaria drug policy review should be institutionalized in endemic countries and based on systematically collected data. Key stakeholders need to be identified early and engaged in the process, while improved communication is needed on all levels. Although malaria drug policy change is often perceived to be a daunting task, using these and other proven strategies should assist endemic countries to tackle this challenge in a systematic fashion that ensures the development and implementation of the rational malaria drug policy.

High sensitivity and specificity of clinical microscopy in rural health facilities in western Kenya under an external quality assurance program.

PubMed

Wafula, Rebeccah; Sang, Edna; Cheruiyot, Olympia; Aboto, Angeline; Menya, Diana; O'Meara, Wendy Prudhomme

2014-09-01

Microscopic diagnosis of malaria is a well-established and inexpensive technique that has the potential to provide accurate diagnosis of malaria infection. However, it requires both training and experience. Although it is considered the gold standard in research settings, the sensitivity and specificity of routine microscopy for clinical care in the primary care setting has been reported to be unacceptably low. We established a monthly external quality assurance program to monitor the performance of clinical microscopy in 17 rural health centers in western Kenya. The average sensitivity over the 12-month period was 96% and the average specificity was 88%. We identified specific contextual factors that contributed to inadequate performance. Maintaining high-quality malaria diagnosis in high-volume, resource-constrained health facilities is possible. © The American Society of Tropical Medicine and Hygiene.

Blood Interferon Signatures Putatively Link Lack of Protection Conferred by the RTS,S Recombinant Malaria Vaccine to an Antigen-specific IgE Response

PubMed Central

Rinchai, Darawan; Presnell, Scott; Vidal, Marta; Dutta, Sheetij; Chauhan, Virander; Cavanagh, David; Moncunill, Gemma; Dobaño, Carlota; Chaussabel, Damien

2017-01-01

Malaria remains a major cause of mortality and morbidity worldwide. Progress has been made in recent years with the development of vaccines that could pave the way towards protection of hundreds of millions of exposed individuals. Here we used a modular repertoire approach to re-analyze a publically available microarray blood transcriptome dataset monitoring the response to malaria vaccination. We report the seminal identification of interferon signatures in the blood of subjects on days 1, 3 and 14 following administration of the third dose of the RTS,S recombinant malaria vaccine. These signatures at day 1 correlate with protection, and at days 3 and 14 to susceptibility to subsequent challenge of study subjects with live parasites. In addition we putatively link the decreased abundance of interferon-inducible transcripts observed at days 3 and 14 post-vaccination with the elicitation of an antigen-specific IgE response in a subset of vaccine recipients that failed to be protected by the RTS,S vaccine. Furthermore, profiling of antigen-specific levels of IgE in a Mozambican cohort of malaria-exposed children vaccinated with RTS,S identified an association between elevated baseline IgE levels and subsequent development of naturally acquired malaria infection during follow up. Taken together these findings warrant further investigation of the role of antigen-specific IgE in conferring susceptibility to malaria infection. PMID:28883910

Experimental Evaluations of Two Strategies to Improve Reading Achievement in Kenya: Enhanced Literacy Instruction and Treatment of Malaria

ERIC Educational Resources Information Center

Jukes, Matthew; Dubeck, Margaret; Brooker, Simon; Wolf, Sharon

2012-01-01

There is less quality evidence on how malaria may affect cognitive abilities and educational achievement or on how schools can tackle the problem of malaria among school children. A randomised trial among Sri Lankan children showed that weekly malaria chemoprophylaxis with chloroquine can improve school examination scores. The Health and Literacy…

From global action against malaria to local issues: state of the art and perspectives of web platforms dealing with malaria information.

PubMed

Briand, Dominique; Roux, Emmanuel; Desconnets, Jean Christophe; Gervet, Carmen; Barcellos, Christovam

2018-03-21

Since prehistory to present times and despite a rough combat against it, malaria remains a concern for human beings. While evolutions of science and technology through times allowed for some infectious diseases eradication in the 20th century, malaria resists. This review aims at assessing how Internet and web technologies are used in fighting malaria. Precisely, how do malaria fighting actors profit from these developments, how do they deal with ensuing phenomena, such as the increase of data volume, and did these technologies bring new opportunities for fighting malaria? Eleven web platforms linked to spatio-temporal malaria information are reviewed, focusing on data, metadata, web services and categories of users. Though the web platforms are highly heterogeneous the review reveals that the latest advances in web technologies are underused. Information are rarely updated dynamically, metadata catalogues are absent, web services are more and more used, but rarely standardized, and websites are mainly dedicated to scientific communities, essentially researchers. Improvement of systems interoperability, through standardization, is an opportunity to be seized in order to allow real time information exchange and online multisource data analysis. To facilitate multidisciplinary/multiscale studies, the web of linked data and the semantic web innovations can be used in order to formalize the different view points of actors involved in the combat against malaria. By doing so, new malaria fighting strategies could take place, to tackle the bottlenecks listed in the United Nation Millennium Development Goals reports, but also specific issues highlighted by the World Health Organization such as malaria elimination in international borders.

Defining equity in physical access to clinical services using geographical information systems as part of malaria planning and monitoring in Kenya

PubMed Central

Noor, A. M.; Zurovac, D.; Hay, S. I.; Ochola, S. A.; Snow, R. W.

2010-01-01

Summary Distance is a crucial feature of health service use and yet its application and utility to health care planning have not been well explored, particularly in the light of large-scale international and national efforts such as Roll Back Malaria. We have developed a high-resolution map of population-to-service access in four districts of Kenya. Theoretical physical access, based upon national targets, developed as part of the Kenyan health sector reform agenda, was compared with actual health service usage data among 1668 paediatric patients attending 81 sampled government health facilities. Actual and theoretical use were highly correlated. Patients in the larger districts of Kwale and Makueni, where access to government health facilities was relatively poor, travelled greater mean distances than those in Greater Kisii and Bondo. More than 60% of the patients in the four districts attended health facilities within a 5-km range. Interpolated physical access surfaces across districts highlighted areas of poor access and large differences between urban and rural settings. Users from rural communities travelled greater distances to health facilities than those in urban communities. The implications of planning and monitoring equitable delivery of clinical services at national and international levels are discussed. PMID:14516303

Primaquine for prevention of malaria in travelers.

PubMed

Baird, J Kevin; Fryauff, David J; Hoffman, Stephen L

2003-12-15

An expanding risk and range of endemic malaria threatens travelers. Primaquine is an old drug recently demonstrated to offer effective prophylaxis. Clinical trials conducted in Indonesia, Kenya, and Colombia showed that a primaquine base (30 mg per day) had protective efficacy against Plasmodium falciparum and Plasmodium vivax of 85%-93%. Among 339 children (age, >8 years) and adults taking this regimen for 12-52 weeks, there was no greater risk of adverse symptomatic events among primaquine users than among recipients of placebo in double-blind studies. Among 151 subjects evaluated after 20 or 52 weeks of daily primaquine therapy, methemoglobinemia was found to be mild (<13%; typically <6%) and transient (duration, <2 weeks). We consider primaquine base (0.5 mg/kg per day consumed with food) to be safe, well-tolerated, and effective prophylaxis against malaria for nonpregnant persons and those with normal glucose-6-phosphate dehydrogenase levels. Primaquine's major advantage over most drugs for chemoprophylaxis is that it does not have to be taken before entering or beyond 3 days after leaving a malarious area.

Principles, practices and knowledge of clinicians when assessing febrile children: a qualitative study in Kenya.

PubMed

Hooft, Anneka M; Ripp, Kelsey; Ndenga, Bryson; Mutuku, Francis; Vu, David; Baltzell, Kimberly; Masese, Linnet N; Vulule, John; Mukoko, Dunstan; LaBeaud, A Desiree

2017-09-20

Clinicians in low resource settings in malaria endemic regions face many challenges in diagnosing and treating febrile illnesses in children. Given the change in WHO guidelines in 2010 that recommend malaria testing prior to treatment, clinicians are now required to expand the differential when malaria testing is negative. Prior studies have indicated that resource availability, need for additional training in differentiating non-malarial illnesses, and lack of understanding within the community of when to seek care play a role in effective diagnosis and treatment. The objective of this study was to examine the various factors that influence clinician behavior in diagnosing and managing children presenting with fever to health centres in Kenya. A total of 20 clinicians (2 paediatricians, 1 medical officer, 2 nurses, and 15 clinical officers) were interviewed, working at 5 different government-sponsored public clinic sites in two areas of Kenya where malaria is prevalent. Clinicians were interviewed one-on-one using a structured interview technique. Interviews were then analysed qualitatively for themes. The following five themes were identified: (1) Strong familiarity with diagnosis of malaria and testing for malaria; (2) Clinician concerns about community understanding of febrile illness, use of traditional medicine, delay in seeking care, and compliance; (3) Reliance on clinical guidelines, history, and physical examination to diagnose febrile illness and recognize danger signs; (4) Clinician discomfort with diagnosis of primary viral illness leading to increased use of empiric antibiotics; and (5) Lack of resources including diagnostic testing, necessary medications, and training modalities contributes to the difficulty clinicians face in assessing and treating febrile illness in children. These themes persisted across all sites, despite variation in levels of medical care. Within these themes, clinicians consistently expressed a need for reliable basic testing

Shifts in malaria vector species composition and transmission dynamics along the Kenyan coast over the past 20 years.

PubMed

Mwangangi, Joseph M; Mbogo, Charles M; Orindi, Benedict O; Muturi, Ephantus J; Midega, Janet T; Nzovu, Joseph; Gatakaa, Hellen; Githure, John; Borgemeister, Christian; Keating, Joseph; Beier, John C

2013-01-08

Over the past 20 years, numerous studies have investigated the ecology and behaviour of malaria vectors and Plasmodium falciparum malaria transmission on the coast of Kenya. Substantial progress has been made to control vector populations and reduce high malaria prevalence and severe disease. The goal of this paper was to examine trends over the past 20 years in Anopheles species composition, density, blood-feeding behaviour, and P. falciparum sporozoite transmission along the coast of Kenya. Using data collected from 1990 to 2010, vector density, species composition, blood-feeding patterns, and malaria transmission intensity was examined along the Kenyan coast. Mosquitoes were identified to species, based on morphological characteristics and DNA extracted from Anopheles gambiae for amplification. Using negative binomial generalized estimating equations, mosquito abundance over the period were modelled while adjusting for season. A multiple logistic regression model was used to analyse the sporozoite rates. Results show that in some areas along the Kenyan coast, Anopheles arabiensis and Anopheles merus have replaced An. gambiae sensu stricto (s.s.) and Anopheles funestus as the major mosquito species. Further, there has been a shift from human to animal feeding for both An. gambiae sensu lato (s.l.) (99% to 16%) and An. funestus (100% to 3%), and P. falciparum sporozoite rates have significantly declined over the last 20 years, with the lowest sporozoite rates being observed in 2007 (0.19%) and 2008 (0.34%). There has been, on average, a significant reduction in the abundance of An. gambiae s.l. over the years (IRR = 0.94, 95% CI 0.90-0.98), with the density standing at low levels of an average 0.006 mosquitoes/house in the year 2010. Reductions in the densities of the major malaria vectors and a shift from human to animal feeding have contributed to the decreased burden of malaria along the Kenyan coast. Vector species composition remains heterogeneous but in

Childhood Disability Risk Factors in Kenya: Impact of Poverty and Other Socio-Demographics

ERIC Educational Resources Information Center

Mugoya, George C. T.; Mutua, Kagendo N.

2015-01-01

The overarching purpose of this study was to ascertain the prevalence of maternal and infant/child health indices that have an established link to childhood disability (CHD) and their association with socio-economic status (SES) in Kenya. Data were drawn from the 2008/2009 Kenya Demographic and Health Survey. Descriptive and weighted Pearson's…

The impact of primary health care on malaria morbidity - defining access by disease burden

PubMed Central

O’Meara, W.P.; Noor, A.; Gatakaa, H.; Tsofa, B.; McKenzie, F. E.; Marsh, K.

2009-01-01

Objectives The convergence of malaria endemicity and poor health care infrastructure has resulted in persistently high rates of malaria morbidity and mortality in many parts of sub-Saharan Africa. Primary care facilities are increasingly becoming the focal point for distribution of intervention strategies, but physical access to these facilities may limit the extent to which communities can be reached. Here we investigate the impact of travel time to primary care on the incidence of hospitalized malaria episodes in a rural district in Kenya. Methods The incidence of hospitalized malaria in a population under continuous demographic surveillance was recorded over three years. The time to travel to the nearest primary health care facility was calculated for every child between birth and five years of age and trends in incidence of hospitalized malaria as a function of travel time were evaluated. Results and conclusions We show that the incidence of hospitalized malaria more than doubled as travel time to the nearest primary care facility increased from ten minutes up to two hours. Good access to primary health facilities may reduce the burden of disease by as much as 66%. Our results highlight both the potential of the primary health care system in reaching those most at risk and reducing the disease burden, and that insufficient access is an important risk factor, one that may be inequitably distributed to the poorest households. PMID:19121148

Tracking the mutual shaping of the technical and social dimensions of solar-powered mosquito trapping systems (SMoTS) for malaria control on Rusinga Island, western Kenya.

PubMed

Oria, Prisca A; Hiscox, Alexandra; Alaii, Jane; Ayugi, Margaret; Mukabana, Wolfgang Richard; Takken, Willem; Leeuwis, Cees

2014-11-18

There has been increasing effort in recent years to incorporate user needs in technology design and re-design. This project employed a bottom-up approach that engaged end users from the outset. Bottom-up approaches have the potential to bolster novel interventions and move them towards adaptive and evidence-based strategies. The present study concerns an innovative use of solar-powered mosquito trapping systems (SMoTS) to control malaria in western Kenya. Our paper highlights the co-dependence of research associated with the development of the SMoTS technology on one hand and research for enhancing the sustainable uptake of that very same intervention within the community on the other. During the pre-intervention year, we examined the design, re-design and piloting of a novel technology to generate lessons for malaria elimination on Rusinga Island. Initial ideas about many technological necessities were evaluated and re-designed following feedback from various sources, including technical and social research as well as broader interactions with the social environment. We documented the interlocking of the multiple processes and activities that took place through process observation and document reviews. We analysed the data within the conceptual framework of system innovation by identifying mutual shaping between technical and social factors. Our findings illustrate how various project stakeholders including project staff, collaborators, donor, and community members simultaneously pursued interdependent technological transformations and social interests. In the ongoing process, we observed how partial outcomes in the technological domain influenced social events at a later phase and vice versa. Looking at malaria intervention projects employing novel technologies as niches that may evolve towards system innovation, helps to reveal interrelations between the various technical and social aspects. Revealing these interrelations requires a different role for research

Monitoring Malaria Vector Control Interventions: Effectiveness of Five Different Adult Mosquito Sampling Methods

PubMed Central

Onyango, Shirley A.; Kitron, Uriel; Mungai, Peter; Muchiri, Eric M.; Kokwaro, Elizabeth; King, Charles H.; Mutuku, Francis M.

2014-01-01

Long-term success of ongoing malaria control efforts based on mosquito bed nets (long-lasting insecticidal net) and indoor residual spraying is dependent on continuous monitoring of mosquito vectors, and thus on effective mosquito sampling tools. The objective of our study was to identify the most efficient mosquito sampling tool(s) for routine vector surveillance for malaria and lymphatic filariasis transmission in coastal Kenya. We evaluated relative efficacy of five collection methods—light traps associated with a person sleeping under a net, pyrethrum spray catches, Prokopack aspirator, clay pots, and urine-baited traps—in four villages representing three ecological settings along the south coast of Kenya. Of the five methods, light traps were the most efficient for collecting female Anopheles gambiae s.l. (Giles) (Diptera: Culicidae) and Anopheles funestus (Giles) (Diptera: Culicidae) mosquitoes, whereas the Prokopack aspirator was most efficient in collecting Culex quinquefasciatus (Say) (Diptera: Culicidae) and other culicines. With the low vector densities here, and across much of sub-Saharan Africa, wherever malaria interventions, long-lasting insecticidal nets, and/or indoor residual spraying are in place, the use of a single mosquito collection method will not be sufficient to achieve a representative sample of mosquito population structure. Light traps will remain a relevant tool for host-seeking mosquitoes, especially in the absence of human landing catches. For a fair representation of the indoor mosquito population, light traps will have to be supplemented with aspirator use, which has potential for routine monitoring of indoor resting mosquitoes, and can substitute the more labor-intensive and intrusive pyrethrum spray catches. There are still no sufficiently efficient mosquito collection methods for sampling outdoor mosquitoes, particularly those that are bloodfed. PMID:24180120

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.

User and Provider Acceptability of Intermittent Screening and Treatment and Intermittent Preventive Treatment with Dihydroartemisinin-Piperaquine to Prevent Malaria in Pregnancy in Western Kenya.

PubMed

Hill, Jenny; Hoyt, Jenna; Achieng, Florence; Ouma, Peter; L'lanziva, Anne; Kariuki, Simon; Desai, Meghna; Webster, Jayne

2016-01-01

The World Health Organization recommends intermittent preventive treatment in pregnancy (IPTp) with sulphadoxine-pyrimethamine (SP) alongside long-lasting insecticide-treated nets (LLIN) and case management for reducing the risks associated with malaria in pregnancy in areas of moderate-to-high transmission in sub-Saharan Africa. Due to increasing Plasmodium falciparum resistance to SP, the search for alternative drugs or strategies to control malaria in pregnancy is a priority. We assessed the acceptability among pregnant women and health providers of intermittent screening and treatment (ISTp) and IPTp with dihydroartemisinin-piperaquine (DP) as alternative strategies in the context of an un-blinded clinical trial. Qualitative data were collected through ten focus group discussions with women participating in a randomized controlled trial to evaluate ISTp or IPTp with DP (multi-day regimen) versus IPTp with SP (single dose) in western Kenya. Individual in-depth interviews were conducted with 26 health providers working in the trial facilities and trial staff. Women appreciated the advantages of being tested with a rapid diagnostic test (RDT) at every ANC visit (although a few women disliked finger pricks) and accepted that they would not receive any antimalarial when tested RDT-negative. There were differences in women's experiences of the efficacy of antimalarials between the trial arms, with more women in the IPTp-SP arm reporting they had experienced malaria episodes. Side effects were experienced among women taking DP and SP. Although women and trial staff reported adherence to the full DP regimen within the trial, health providers were not confident that women would adhere to multi-day regimens in non-trial settings. Health providers recognized the advantages of ISTp in reducing unnecessary exposure to drugs, but lacked confidence in the reliability of RDTs compared to microscopy. Our findings indicate that, within a trial context, ISTp-DP and IPTp-DP were

Quality of malaria information provided on Internet travel operator websites.

PubMed

Bazaz, Rohit; Green, Edward; Green, Steve T

2010-09-01

Over the past 20 years, there has been a steady growth in the number of reported cases of malaria in the UK. With increasing Internet flight sales over recent years, online travel operator websites may be the only place many travellers could conceivably receive pre-travel malaria prevention advice. 29 Travel operator websites which allow for online flight purchases to malarious areas from the UK, identified using a Google(®) web search and the website of the International Air Transport Association, were assessed for the existence, accuracy and accessibility of malaria prevention advice available through internal and external website links. Eight (28%) websites provided malaria prevention information on their own pages. Five (17%) websites contained country specific malaria information relevant to the requested destination, including variation of malaria risk within that country and accurate destination specific chemoprophylaxis advice. No malaria information was available, either on internal or external links, on 8 (28%) websites. On average, it took 2.4 additional mouse clicks to access malaria information during the online flight booking process. Six of the 29 websites (21%) allowed for access to information with only 1 click. Malaria prevention information on online travel operator websites is most often absent or inadequate. Even on websites where such information is of good quality, it can be difficult to access. The travel industry should introduce and enforce guidelines for the malaria information provided by online travel operators. Copyright © 2010 Elsevier Ltd. All rights reserved.

Malaria prevalence defined by microscopy, antigen detection, DNA amplification and total nucleic acid amplification in a malaria-endemic region during the peak malaria transmission season.

PubMed

Waitumbi, John N; Gerlach, Jay; Afonina, Irina; Anyona, Samuel B; Koros, Joseph N; Siangla, Joram; Ankoudinova, Irina; Singhal, Mitra; Watts, Kate; Polhemus, Mark E; Vermeulen, Nicolaas M; Mahoney, Walt; Steele, Matt; Domingo, Gonzalo J

2011-07-01

To determine the malaria prevalence by microscopy, antigen detection and nucleic acid detection in a defined subpopulation in a Plasmodium falciparum-endemic region during the peak transmission season. Blood specimens were collected in a cross-sectional study involving children aged 5-10 years (n = 195) presenting with acute fever to two clinics in Western Kenya. All specimens underwent microscopy, HRP2 and aldolase antigen detection by enzyme immunoassay (EIA), parasite-specific DNA and total nucleic acid (RNA and DNA) by real-time PCR (qPCR) and reverse-transcriptase PCR (qRT-PCR). Microscopy detected 65/195 cases of malaria infection [95% confidence interval (CI) 52-78]. HRP2 and aldolase EIA had similar sensitivity levels detecting antigen in 65/195 (95% CI, 52-78) and 57/195 (95% CI, 45-70) cases. Discordants in antigen detection vs. microscopy occurred at <470 parasites/μl and <4900 parasites/μl for HRP2 and aldolase, respectively. Detection of total nucleic acid allowed a 3 log lower limit of detection than just DNA detection by real-time PCR in vitro. In clinical specimens, 114/195 (95% CI, 100-127) were qPCR positive (DNA), and 187/195 (95% CI, 179-191) were qRT-PCR positive (DNA plus RNA). The prevalence of submicroscopic malaria infection was significantly higher when detecting total nucleic acid than just DNA in this outpatient population during the high transmission season. Defining standards for submicroscopic infection will be important for control programmes, diagnostics development efforts and molecular epidemiology studies. © 2011 Blackwell Publishing Ltd.

Training Initiatives within the AFHSC-Global Emerging Infections Surveillance and Response System: Support for IHR (2005)

DTIC Science & Technology

2011-03-04

Medical Research Unit-Kenya (USAMRU- K) Malaria Diagnostics Center of Excellence The continued operation of the Malaria Diagnostics Center of Excellence...MDCoE) in Kisumu, Kenya, pro- vided important contributions in professional malaria diagnostic training. The MDCoE was established in 2004 with AFHSC...202009.pdf]. 11. Ohrt C, Obare P, Nanakorn A, et al: Establishing a malaria diagnostics centre of excellence in Kisumu, Kenya. Malar J 2007, 6(79). 12

Targeting imported malaria through social networks: a potential strategy for malaria elimination in Swaziland.

PubMed

Koita, Kadiatou; Novotny, Joseph; Kunene, Simon; Zulu, Zulizile; Ntshalintshali, Nyasatu; Gandhi, Monica; Gosling, Roland

2013-06-27

Swaziland has made great progress towards its goal of malaria elimination by 2015. However, malaria importation from neighbouring high-endemic Mozambique through Swaziland's eastern border remains a major factor that could prevent elimination from being achieved. In order to reach elimination, Swaziland must rapidly identify and treat imported malaria cases before onward transmission occurs. A nationwide formative assessment was conducted over eight weeks to determine if the imported cases of malaria identified by the Swaziland National Malaria Control Programme could be linked to broader social networks and to explore methods to access these networks. Using a structured format, interviews were carried out with malaria surveillance agents (6), health providers (10), previously identified imported malaria cases (19) and people belonging to the networks identified through these interviews (25). Most imported malaria cases were Mozambicans (63%, 12/19) making a living in Swaziland and sustaining their families in Mozambique. The majority of imported cases (73%, 14/19) were labourers and self-employed contractors who travelled frequently to Mozambique to visit their families and conduct business. Social networks of imported cases with similar travel patterns were identified through these interviews. Nearly all imported cases (89%, 17/19) were willing to share contact information to enable network members to be interviewed. Interviews of network members and key informants revealed common congregation points, such as the urban market places in Manzini and Malkerns, as well as certain bus stations, where people with similar travel patterns and malaria risk behaviours could be located and tested for malaria. This study demonstrated that imported cases of malaria belonged to networks of people with similar travel patterns. This study may provide novel methods for screening high-risk groups of travellers using both snowball sampling and time-location sampling of networks to

Detecting Malaria Hotspots: A Comparison of Rapid Diagnostic Test, Microscopy, and Polymerase Chain Reaction

PubMed Central

Mogeni, Polycarp; Williams, Thomas N; Omedo, Irene; Kimani, Domtila; Ngoi, Joyce M; Mwacharo, Jedida; Morter, Richard; Nyundo, Christopher; Wambua, Juliana; Nyangweso, George; Kapulu, Melissa; Fegan, Gregory; Bejon, Philip

2017-01-01

Abstract Background Malaria control strategies need to respond to geographical hotspots of transmission. Detection of hotspots depends on the sensitivity of the diagnostic tool used. Methods We conducted cross-sectional surveys in 3 sites within Kilifi County, Kenya, that had variable transmission intensities. Rapid diagnostic test (RDT), microscopy, and polymerase chain reaction (PCR) were used to detect asymptomatic parasitemia, and hotspots were detected using the spatial scan statistic. Results Eight thousand five hundred eighty-one study participants were surveyed in 3 sites. There were statistically significant malaria hotspots by RDT, microscopy, and PCR for all sites except by microscopy in 1 low transmission site. Pooled data analysis of hotspots by PCR overlapped with hotspots by microscopy at a moderate setting but not at 2 lower transmission settings. However, variations in degree of overlap were noted when data were analyzed by year. Hotspots by RDT were predictive of PCR/microscopy at the moderate setting, but not at the 2 low transmission settings. We observed long-term stability of hotspots by PCR and microscopy but not RDT. Conclusion Malaria control programs may consider PCR testing to guide asymptomatic malaria hotspot detection once the prevalence of infection falls. PMID:28973672

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

Costing commodity and human resource needs for integrated community case management in thie differing community health strategies of Ethiopia, Kenya and Zambia.

PubMed

Nefdt, Rory; Ribaira, Eric; Diallo, Khassoum

2014-10-01

To ensure correct and appropriate funding is available, there is a need to estimate resource needs for improved planning and implementation of integrated Community Case Management (iCCM). To compare and estimate costs for commodity and human resource needs for iCCM, based on treatment coverage rates, bottlenecks and national targets in Ethiopia, Kenya and Zambia from 2014 to 2016. Resource needs were estimated using Ministry of Health (MoH) targets fronm 2014 to 2016 for implementation of case management of pneumonia, diarrhea and malaria through iCCM based on epidemiological, demographic, economic, intervention coverage and other health system parameters. Bottleneck analysis adjusted cost estimates against system barriers. Ethiopia, Kenya and Zambia were chosen to compare differences in iCCM costs in different programmatic implementation landscapes. Coverage treatment rates through iCCM are lowest in Ethiopia, followed by Kenya and Zambia, but Ethiopia had the greatest increases between 2009 and 2012. Deployment of health extension workers (HEWs) in Ethiopia is more advanced compared to Kenya and Zambia, which have fewer equivalent cadres (called commu- nity health workers (CHWs)) covering a smaller proportion of the population. Between 2014 and 2016, the propor- tion of treatments through iCCM compared to health centres are set to increase from 30% to 81% in Ethiopia, 1% to 18% in Kenya and 3% to 22% in Zambia. The total estimated cost of iCCM for these three years are USD 75,531,376 for Ethiopia, USD 19,839,780 for Kenya and USD 33,667,742 for Zambia. Projected per capita expen- diture for 2016 is USD 0.28 for Ethiopia, USD 0.20 in Kenya and USD 0.98 in Zambia. Commodity costs for pneumonia and diarrhea were a small fraction of the total iCCM budget for all three countries (less than 3%), while around 80% of the costs related to human resources. Analysis of coverage, demography and epidemiology data improves estimates of fimding requirements for iCCM. Bottleneck

HIV Type 1 Transmission Networks Among Men Having Sex with Men and Heterosexuals in Kenya

PubMed Central

Faria, Nuno Rodrigues; Hassan, Amin; Hamers, Raph L.; Mutua, Gaudensia; Anzala, Omu; Mandaliya, Kishor; Cane, Patricia; Berkley, James A.; Rinke de Wit, Tobias F.; Wallis, Carole; Graham, Susan M.; Price, Matthew A.; Coutinho, Roel A.; Sanders, Eduard J.

2014-01-01

Abstract We performed a molecular phylogenetic study on HIV-1 polymerase sequences of men who have sex with men (MSM) and heterosexual patient samples in Kenya to characterize any observed HIV-1 transmission networks. HIV-1 polymerase sequences were obtained from samples in Nairobi and coastal Kenya from 84 MSM, 226 other men, and 364 women from 2005 to 2010. Using Bayesian phylogenetics, we tested whether sequences clustered by sexual orientation and geographic location. In addition, we used trait diffusion analyses to identify significant epidemiological links and to quantify the number of transmissions between risk groups. Finally, we compared 84 MSM sequences with all HIV-1 sequences available online at GenBank. Significant clustering of sequences from MSM at both coastal Kenya and Nairobi was found, with evidence of HIV-1 transmission between both locations. Although a transmission pair between a coastal MSM and woman was confirmed, no significant HIV-1 transmission was evident between MSM and the comparison population for the predominant subtype A (60%). However, a weak but significant link was evident when studying all subtypes together. GenBank comparison did not reveal other important transmission links. Our data suggest infrequent intermingling of MSM and heterosexual HIV-1 epidemics in Kenya. PMID:23947948

Plasmodium malariae and P. ovale genomes provide insights into malaria parasite evolution

PubMed Central

Rutledge, Gavin G.; Böhme, Ulrike; Sanders, Mandy; Reid, Adam J.; Cotton, James A.; Maiga-Ascofare, Oumou; Djimdé, Abdoulaye A.; Apinjoh, Tobias O.; Amenga-Etego, Lucas; Manske, Magnus; Barnwell, John W.; Renaud, François; Ollomo, Benjamin; Prugnolle, Franck; Anstey, Nicholas M.; Auburn, Sarah; Price, Ric N.; McCarthy, James S.; Kwiatkowski, Dominic P.; Newbold, Chris I.; Berriman, Matthew; Otto, Thomas D.

2017-01-01

Elucidation of the evolutionary history and interrelatedness of Plasmodium species that infect humans has been hampered by a lack of genetic information for three human-infective species: P. malariae and two P. ovale species (P. o. curtisi and P. o. wallikeri)1. These species are prevalent across most regions in which malaria is endemic2,3 and are often undetectable by light microscopy4, rendering their study in human populations difficult5. The exact evolutionary relationship of these species to the other human-infective species has been contested6,7. Using a new reference genome for P. malariae and a manually curated draft P. o. curtisi genome, we are now able to accurately place these species within the Plasmodium phylogeny. Sequencing of a P. malariae relative that infects chimpanzees reveals similar signatures of selection in the P. malariae lineage to another Plasmodium lineage shown to be capable of colonization of both human and chimpanzee hosts. Molecular dating suggests that these host adaptations occurred over similar evolutionary timescales. In addition to the core genome that is conserved between species, differences in gene content can be linked to their specific biology. The genome suggests that P. malariae expresses a family of heterodimeric proteins on its surface that have structural similarities to a protein crucial for invasion of red blood cells. The data presented here provide insight into the evolution of the Plasmodium genus as a whole. PMID:28117441

New gorilla adenovirus vaccine vectors induce potent immune responses and protection in a mouse malaria model.

PubMed

Limbach, Keith; Stefaniak, Maureen; Chen, Ping; Patterson, Noelle B; Liao, Grant; Weng, Shaojie; Krepkiy, Svetlana; Ekberg, Greg; Torano, Holly; Ettyreddy, Damodar; Gowda, Kalpana; Sonawane, Sharvari; Belmonte, Arnel; Abot, Esteban; Sedegah, Martha; Hollingdale, Michael R; Moormann, Ann; Vulule, John; Villasante, Eileen; Richie, Thomas L; Brough, Douglas E; Bruder, Joseph T

2017-07-03

A DNA-human Ad5 (HuAd5) prime-boost malaria vaccine has been shown to protect volunteers against a controlled human malaria infection. The potency of this vaccine, however, appeared to be affected by the presence of pre-existing immunity against the HuAd5 vector. Since HuAd5 seroprevalence is very high in malaria-endemic areas of the world, HuAd5 may not be the most appropriate malaria vaccine vector. This report describes the evaluation of the seroprevalence, immunogenicity and efficacy of three newly identified gorilla adenoviruses, GC44, GC45 and GC46, as potential malaria vaccine vectors. The seroprevalence of GC44, GC45 and GC46 is very low, and the three vectors are not efficiently neutralized by human sera from Kenya and Ghana, two countries where malaria is endemic. In mice, a single administration of GC44, GC45 and GC46 vectors expressing a murine malaria gene, Plasmodium yoelii circumsporozoite protein (PyCSP), induced robust PyCSP-specific T cell and antibody responses that were at least as high as a comparable HuAd5-PyCSP vector. Efficacy studies in a murine malaria model indicated that a prime-boost regimen with DNA-PyCSP and GC-PyCSP vectors can protect mice against a malaria challenge. Moreover, these studies indicated that a DNA-GC46-PyCSP vaccine regimen was significantly more efficacious than a DNA-HuAd5-PyCSP regimen. These data suggest that these gorilla-based adenovectors have key performance characteristics for an effective malaria vaccine. The superior performance of GC46 over HuAd5 highlights its potential for clinical development.

Standardizing operational vector sampling techniques for measuring malaria transmission intensity: evaluation of six mosquito collection methods in western Kenya.

PubMed

Wong, Jacklyn; Bayoh, Nabie; Olang, George; Killeen, Gerry F; Hamel, Mary J; Vulule, John M; Gimnig, John E

2013-04-30

Operational vector sampling methods lack standardization, making quantitative comparisons of malaria transmission across different settings difficult. Human landing catch (HLC) is considered the research gold standard for measuring human-mosquito contact, but is unsuitable for large-scale sampling. This study assessed mosquito catch rates of CDC light trap (CDC-LT), Ifakara tent trap (ITT), window exit trap (WET), pot resting trap (PRT), and box resting trap (BRT) relative to HLC in western Kenya to 1) identify appropriate methods for operational sampling in this region, and 2) contribute to a larger, overarching project comparing standardized evaluations of vector trapping methods across multiple countries. Mosquitoes were collected from June to July 2009 in four districts: Rarieda, Kisumu West, Nyando, and Rachuonyo. In each district, all trapping methods were rotated 10 times through three houses in a 3 × 3 Latin Square design. Anophelines were identified by morphology and females classified as fed or non-fed. Anopheles gambiae s.l. were further identified as Anopheles gambiae s.s. or Anopheles arabiensis by PCR. Relative catch rates were estimated by negative binomial regression. When data were pooled across all four districts, catch rates (relative to HLC indoor) for An. gambiae s.l (95.6% An. arabiensis, 4.4% An. gambiae s.s) were high for HLC outdoor (RR = 1.01), CDC-LT (RR = 1.18), and ITT (RR = 1.39); moderate for WET (RR = 0.52) and PRT outdoor (RR = 0.32); and low for all remaining types of resting traps (PRT indoor, BRT indoor, and BRT outdoor; RR < 0.08 for all). For Anopheles funestus, relative catch rates were high for ITT (RR = 1.21); moderate for HLC outdoor (RR = 0.47), CDC-LT (RR = 0.69), and WET (RR = 0.49); and low for all resting traps (RR < 0.02 for all). At finer geographic scales, however, efficacy of each trap type varied from district to district. ITT, CDC-LT, and WET appear to be effective methods for large-scale vector sampling in

Relationship Transitions among Youth in Urban Kenya

ERIC Educational Resources Information Center

Clark, Shelley; Kabiru, Caroline; Mathur, Rohini

2010-01-01

The process of courtship and marriage in sub-Saharan Africa has changed remarkably. These changes, however, have received scant attention because recent research has focused on adolescent relationships' links to HIV/AIDS rather than to marriage. Drawing on detailed reports of 1,365 romantic and sexual partnerships from youths in Kisumu, Kenya, we…

Evaluating Different Dimensions of Programme Effectiveness for Private Medicine Retailer Malaria Control Interventions in Kenya

PubMed Central

Abuya, Timothy O.; Fegan, Greg; Amin, Abdinasir A.; Akhwale, Willis S.; Noor, Abdisalan M.; Snow, Robert W.; Marsh, Vicki

2010-01-01

Background Private medicine retailers (PMRs) are key partners in the home management of fevers in many settings. Current evidence on effectiveness for PMR interventions at scale is limited. This study presents evaluation findings of two different programs implemented at moderate scale targeting PMRs for malaria control in the Kisii and Kwale districts of Kenya. Key components of this evaluation were measurement of program performance, including coverage, PMR knowledge, practices, and utilization based on spatial analysis. Methodology/Principal Findings The study utilized mixed quantitative methods including retail audits and surrogate client surveys based on post-intervention cross-sectional surveys in intervention and control areas and mapping of intervention outlets. There was a large and significant impact on PMR knowledge and practices of the program in Kisii, with 60.5% of trained PMRs selling amodiaquine medicines in adequate doses compared to 2.8% of untrained ones (OR; 53.5: 95% CI 6.7, 428.3), a program coverage of 69.7% targeted outlets, and a potential utilization of about 30,000 children under five. The evaluation in Kwale also indicates a significant impact with 18.8% and 2.3% intervention and control PMRs selling amodiaquine with correct advice, respectively (OR; 9.4: 95% CI 1.1, 83.7), a program coverage of 25.3% targeted outlets, and a potential utilization of about 48,000 children under five. A provisional benchmark of 7.5 km was a reasonable threshold distance for households to access PMR services. Conclusions/Significance This evaluation show that PMR interventions operationalized in the district level settings are likely to impact PMR knowledge and practices and lead to increased coverage of appropriate treatment to target populations. There is value of evaluating different dimensions of public health programs, including quality, spatial access, and implementation practice. This approach strengthens the potential contribution of pragmatic study

Use of dipstick tests for the rapid diagnosis of malaria in nonimmune travelers.

PubMed

Jelinek, T; Grobusch, M P; Nothdurft, H D

2000-01-01

Swift diagnosis of falciparum malaria in nonendemic areas is frequently complicated by lack of experience on the side of involved laboratory personnel. Diagnostic tools based on the dipstick principle for the detection of plasmodial histidine-rich protein 2 (HRP-2) (ICT Malaria P.f. (R)) and parasite-specific lactate-dehydrogenase (pLDH) (OptiMal(R)), respectively, have become available for the qualitative detection of falciparum malaria. In order to evaluate currently available assays, a series of studies was conducted: sensitivity and specificity were evaluated by investigation of specimens from 231 febrile returnees from endemic areas, cross reactivity in patients with rheumatoid factor (RF) was assessed among 92 patients from a rheumatology unit, and the quality of dipstick self-use by febrile travelers was tested in Kenya. Whereas the test kit based on the detection of HRP-2 performed with a sensitivity of 92.5% and a specificity of 98.3%, the kit for the detection of pLDH showed a sensitivity of 88.5% and a specificity of 99.4%. Cross-reactions with sera positive for rheumatoid factor occurred in 6.6% with the ICT Malaria P.f.(R), and in 3.3% with the OptiMal(R) test. Only ICT Malaria P.f.(R) was tested for quality of self-use among travelers. This dipstick assay was performed successfully by 67 patients (68.4%), but 31 (31.6%) were unable to obtain a result. Dipstick tests have the potential of enhancing speed and accuracy of the diagnosis of falciparum malaria, especially if nonspecialized laboratories are involved. However, microscopical testing remains mandatory in every single patient with the possible diagnosis of malaria. Self-use of dipstick tests for malaria diagnosis by travelers should only be recommended after appropriate instruction and training, including a successful performance of the test procedure.

Skill of ENSEMBLES seasonal re-forecasts for malaria prediction in West Africa

NASA Astrophysics Data System (ADS)

Jones, A. E.; Morse, A. P.

2012-12-01

This study examines the performance of malaria-relevant climate variables from the ENSEMBLES seasonal ensemble re-forecasts for sub-Saharan West Africa, using a dynamic malaria model to transform temperature and rainfall forecasts into simulated malaria incidence and verifying these forecasts against simulations obtained by driving the malaria model with General Circulation Model-derived reanalysis. Two subregions of forecast skill are identified: the highlands of Cameroon, where low temperatures limit simulated malaria during the forecast period and interannual variability in simulated malaria is closely linked to variability in temperature, and northern Nigeria/southern Niger, where simulated malaria variability is strongly associated with rainfall variability during the peak rain months.

Landscape Ecology and Epidemiology of Malaria Associated with Rubber Plantations in Thailand: Integrated Approaches to Malaria Ecotoping

PubMed Central

Kaewwaen, Wuthichai

2015-01-01

The agricultural land use changes that are human-induced changes in agroforestry ecosystems and in physical environmental conditions contribute substantially to the potential risks for malaria transmission in receptive areas. Due to the pattern and extent of land use change, the risks or negatively ecosystemic outcomes are the results of the dynamics of malaria transmission, the susceptibility of human populations, and the geographical distribution of malaria vectors. This review focused basically on what are the potential effects of agricultural land use change as a result of the expansion of rubber plantations in Thailand and how significant the ecotopes of malaria-associated rubber plantations (MRP) are. More profoundly, this review synthesized the novel concepts and perspectives on applied landscape ecology and epidemiology of malaria, as well as approaches to determine the degree to which an MRP ecotope as fundamental landscape scale can establish malaria infection pocket(s). Malaria ecotoping encompasses the integrated approaches and tools applied to or used in modeling malaria transmission. The scalability of MRP ecotope depends upon its unique landscape structure as it is geographically associated with the infestation or reinfestation of Anopheles vectors, along with the attributes that are epidemiologically linked with the infections. The MRP ecotope can be depicted as the hotspot such that malaria transmission is modeled upon the MRP factors underlying human settlements and movement activities, health behaviors, land use/land cover change, malaria vector population dynamics, and agrienvironmental and climatic conditions. The systemic and uniform approaches to malaria ecotoping underpin the stratification of the potential risks for malaria transmission by making use of remotely sensed satellite imagery or landscape aerial photography using unmanned aerial vehicle (UAV), global positioning systems (GPS), and geographical information systems (GIS). PMID

Comparison of Routine Health Management Information System Versus Enhanced Inpatient Malaria Surveillance for Estimating the Burden of Malaria Among Children Admitted to Four Hospitals in Uganda

PubMed Central

Mpimbaza, Arthur; Miles, Melody; Sserwanga, Asadu; Kigozi, Ruth; Wanzira, Humphrey; Rubahika, Denis; Nasr, Sussann; Kapella, Bryan K.; Yoon, Steven S.; Chang, Michelle; Yeka, Adoke; Staedke, Sarah G.; Kamya, Moses R.; Dorsey, Grant

2015-01-01

The primary source of malaria surveillance data in Uganda is the Health Management Information System (HMIS), which does not require laboratory confirmation of reported malaria cases. To improve data quality, an enhanced inpatient malaria surveillance system (EIMSS) was implemented with emphasis on malaria testing of all children admitted in select hospitals. Data were compared between the HMIS and the EIMSS at four hospitals over a period of 12 months. After the implementation of the EIMSS, over 96% of admitted children under 5 years of age underwent laboratory testing for malaria. The HMIS significantly overreported the proportion of children under 5 years of age admitted with malaria (average absolute difference = 19%, range = 8–27% across the four hospitals) compared with the EIMSS. To improve the quality of the HMIS data for malaria surveillance, the National Malaria Control Program should, in addition to increasing malaria testing rates, focus on linking laboratory test results to reported malaria cases. PMID:25422396

The clinical burden of malaria in Nairobi: a historical review and contemporary audit

PubMed Central

2011-01-01

Background Widespread urbanization over the next 20 years has the potential to drastically change the risk of malaria within Africa. The burden of the disease, its management, risk factors and appropriateness of targeted intervention across varied urban environments in Africa remain largely undefined. This paper presents a combined historical and contemporary review of the clinical burden of malaria within one of Africa's largest urban settlements, Nairobi, Kenya. Methods A review of historical reported malaria case burdens since 1911 within Nairobi was undertaken using archived government and city council reports. Contemporary information on out-patient case burdens due to malaria were assembled from the National Health Management and Information System (HMIS). Finally, an audit of 22 randomly selected health facilities within Nairobi was undertaken covering 12 months 2009-2010. The audit included interviews with health workers, and a checklist of commodities and guidelines necessary to diagnose, treat and record malaria. Results From the 1930's through to the mid-1960's malaria incidence declined coincidental with rapid population growth. During this period malaria notification and prevention were a priority for the city council. From 2001-2008 reporting systems for malaria were inadequate to define the extent or distribution of malaria risk within Nairobi. A more detailed facility review suggests, however that malaria remains a common diagnosis (11% of all paediatric diagnoses made) and where laboratories (n = 15) exist slide positivity rates are on average 15%. Information on the quality of diagnosis, slide reading and whether those reported as positive were imported infections was not established. The facilities and health workers included in this study were not universally prepared to treat malaria according to national guidelines or identify foci of risks due to shortages of national first-line drugs, inadequate record keeping and a view among some health

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

Detecting Malaria Hotspots: A Comparison of Rapid Diagnostic Test, Microscopy, and Polymerase Chain Reaction.

PubMed

Mogeni, Polycarp; Williams, Thomas N; Omedo, Irene; Kimani, Domtila; Ngoi, Joyce M; Mwacharo, Jedida; Morter, Richard; Nyundo, Christopher; Wambua, Juliana; Nyangweso, George; Kapulu, Melissa; Fegan, Gregory; Bejon, Philip

2017-11-27

Malaria control strategies need to respond to geographical hotspots of transmission. Detection of hotspots depends on the sensitivity of the diagnostic tool used. We conducted cross-sectional surveys in 3 sites within Kilifi County, Kenya, that had variable transmission intensities. Rapid diagnostic test (RDT), microscopy, and polymerase chain reaction (PCR) were used to detect asymptomatic parasitemia, and hotspots were detected using the spatial scan statistic. Eight thousand five hundred eighty-one study participants were surveyed in 3 sites. There were statistically significant malaria hotspots by RDT, microscopy, and PCR for all sites except by microscopy in 1 low transmission site. Pooled data analysis of hotspots by PCR overlapped with hotspots by microscopy at a moderate setting but not at 2 lower transmission settings. However, variations in degree of overlap were noted when data were analyzed by year. Hotspots by RDT were predictive of PCR/microscopy at the moderate setting, but not at the 2 low transmission settings. We observed long-term stability of hotspots by PCR and microscopy but not RDT. Malaria control programs may consider PCR testing to guide asymptomatic malaria hotspot detection once the prevalence of infection falls. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Widespread Pyrethroid and DDT Resistance in the Major Malaria Vector Anopheles funestus in East Africa Is Driven by Metabolic Resistance Mechanisms

PubMed Central

Mulamba, Charles; Riveron, Jacob M.; Ibrahim, Sulaiman S.; Irving, Helen; Barnes, Kayla G.; Mukwaya, Louis G.; Birungi, Josephine; Wondji, Charles S.

2014-01-01

Background Establishing the extent, geographical distribution and mechanisms of insecticide resistance in malaria vectors is a prerequisite for resistance management. Here, we report a widespread distribution of insecticide resistance in the major malaria vector An. funestus across Uganda and western Kenya under the control of metabolic resistance mechanisms. Methodology/Principal Findings Female An. funestus collected throughout Uganda and western Kenya exhibited a Plasmodium infection rate between 4.2 to 10.4%. Widespread resistance against both type I (permethrin) and II (deltamethrin) pyrethroids and DDT was observed across Uganda and western Kenya. All populations remain highly susceptible to carbamate, organophosphate and dieldrin insecticides. Knockdown resistance plays no role in the pyrethroid and DDT resistance as no kdr mutation associated with resistance was detected despite the presence of a F1021C replacement. Additionally, no signature of selection was observed on the sodium channel gene. Synergist assays and qRT-PCR indicated that metabolic resistance plays a major role notably through elevated expression of cytochrome P450s. DDT resistance mechanisms differ from West Africa as the L119F-GSTe2 mutation only explains a small proportion of the genetic variance to DDT resistance. Conclusion The extensive distribution of pyrethroid and DDT resistance in East African An. funestus populations represents a challenge to the control of this vector. However, the observed carbamate and organophosphate susceptibility offers alternative solutions for resistance management. PMID:25333491

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

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.

Changing patterns of malaria in south-east Scotland: implications for practitioner awareness and prophylactic advice.

PubMed Central

Willocks, L.; Jones, M.; Brettle, R.; Welsby, P.; Gray, J.

1992-01-01

The medical records of all 229 patients with malaria admitted to the Edinburgh City Hospital between 1969 and 1988 were studied retrospectively. A total of 137 were from Africa, 44 from the Indian subcontinent, 19 from the Far East, 18 from New Guinea, 5 from the Middle East and 3 from South America. The number of yearly admissions rose markedly after 1983, mainly due to an increase in Plasmodium falciparum cases. Ninety-four cases (15 with severe parasitaemia) mainly from Kenya and Nigeria were due to P. falciparum infection and 99 to P. vivax. There were no deaths. A seasonal distribution of onset of fever in patients with P. vivax infections originating from the Indian subcontinent showed that most patients presented during the summer. Prophylaxis had generally been irregular or non-existent but many compliant patients may have been receiving an inadequate dose of chloroquine on a mg/kg body weight basis. General practitioners are likely to see at least one case of malaria every 4 years. They are encouraged to seek advice from a specialist unit whenever necessary whether before or after their patient travels abroad. Travellers, in particular to Kenya and Nigeria, and Asian immigrants to the UK returning on holiday to their country of origin should be strongly advised to take regular prophylaxis including on return to the UK. PMID:1561183

Field Evaluation of a Push-Pull System to Reduce Malaria Transmission

PubMed Central

Menger, David J.; Omusula, Philemon; Holdinga, Maarten; Homan, Tobias; Carreira, Ana S.; Vandendaele, Patrice; Derycke, Jean-Luc; Mweresa, Collins K.; Mukabana, Wolfgang Richard; van Loon, Joop J. A.; Takken, Willem

2015-01-01

Malaria continues to place a disease burden on millions of people throughout the tropics, especially in sub-Saharan Africa. Although efforts to control mosquito populations and reduce human-vector contact, such as long-lasting insecticidal nets and indoor residual spraying, have led to significant decreases in malaria incidence, further progress is now threatened by the widespread development of physiological and behavioural insecticide-resistance as well as changes in the composition of vector populations. A mosquito-directed push-pull system based on the simultaneous use of attractive and repellent volatiles offers a complementary tool to existing vector-control methods. In this study, the combination of a trap baited with a five-compound attractant and a strip of net-fabric impregnated with micro-encapsulated repellent and placed in the eaves of houses, was tested in a malaria-endemic village in western Kenya. Using the repellent delta-undecalactone, mosquito house entry was reduced by more than 50%, while the traps caught high numbers of outdoor flying mosquitoes. Model simulations predict that, assuming area-wide coverage, the addition of such a push-pull system to existing prevention efforts will result in up to 20-fold reductions in the entomological inoculation rate. Reductions of such magnitude are also predicted when mosquitoes exhibit a high resistance against insecticides. We conclude that a push-pull system based on non-toxic volatiles provides an important addition to existing strategies for malaria prevention. PMID:25923114

Increased malaria transmission around irrigation schemes in Ethiopia and the potential of canal water management for malaria vector control.

PubMed

Kibret, Solomon; Wilson, G Glenn; Tekie, Habte; Petros, Beyene

2014-09-13

Irrigation schemes have been blamed for the increase in malaria in many parts of sub-Saharan Africa. However, proper water management could help mitigate malaria around irrigation schemes in this region. This study investigates the link between irrigation and malaria in Central Ethiopia. Larval and adult mosquitoes were collected fortnightly between November 2009 and October 2010 from two irrigated and two non-irrigated (control) villages in the Ziway area, Central Ethiopia. Daily canal water releases were recorded during the study period and bi-weekly correlation analysis was done to determine relationships between canal water releases and larval/adult vector densities. Blood meal sources (bovine vs human) and malaria sporozoite infection were tested using enzyme-linked immunosorbent assay (ELISA). Monthly malaria data were also collected from central health centre of the study villages. Monthly malaria incidence was over six-fold higher in the irrigated villages than the non-irrigated villages. The number of anopheline breeding habitats was 3.6 times higher in the irrigated villages than the non-irrigated villages and the most common Anopheles mosquito breeding habitats were waterlogged field puddles, leakage pools from irrigation canals and poorly functioning irrigation canals. Larval and adult anopheline densities were seven- and nine-fold higher in the irrigated villages than in the non-irrigated villages, respectively, during the study period. Anopheles arabiensis was the predominant species in the study area. Plasmodium falciparum sporozoite rates of An. arabiensis and Anopheles pharoensis were significantly higher in the irrigated villages than the non-irrigated villages. The annual entomological inoculation rate (EIR) calculated for the irrigated and non-irrigated villages were 34.8 and 0.25 P. falciparum infective bites per person per year, respectively. A strong positive correlation was found between bi-weekly anopheline larval density and canal water

Exploring the potential of using cattle for malaria vector surveillance and control: a pilot study in western Kenya.

PubMed

Njoroge, Margaret M; Tirados, Inaki; Lindsay, Steven W; Vale, Glyn A; Torr, Stephen J; Fillinger, Ulrike

2017-01-10

Malaria vector mosquitoes with exophilic and zoophilic tendencies, or with a high acceptance of alternative blood meal sources when preferred human blood-hosts are unavailable, may help maintain low but constant malaria transmission in areas where indoor vector control has been scaled up. This residual transmission might be addressed by targeting vectors outside the house. Here we investigated the potential of insecticide-treated cattle, as routinely used for control of tsetse and ticks in East Africa, for mosquito control. The malaria vector population in the study area was investigated weekly for 8 months using two different trapping tools: light traps indoors and cattle-baited traps (CBTs) outdoors. The effect of the application of the insecticide deltamethrin and the acaricide amitraz on cattle on host-seeking Anopheles arabiensis was tested experimentally in field-cages and the impact of deltamethrin-treated cattle explored under field conditions on mosquito densities on household level. CBTs collected on average 2.8 (95% CI: 1.8-4.2) primary [Anopheles gambiae (s.s.), An. arabiensis and An. funestus (s.s.)] and 6.3 (95% CI: 3.6-11.3) secondary malaria vectors [An. ivulorum and An. coustani (s.l.)] per trap night and revealed a distinct, complementary seasonality. At the same time on average only 1.4 (95% CI: 0.8-2.3) primary and 1.1 (95% CI: 0.6-2.0) secondary malaria vectors were collected per trap night with light traps indoors. Amitraz had no effect on survival of host-seeking An. arabiensis under experimental conditions but deltamethrin increased mosquito mortality (OR 19, 95% CI: 7-50), but only for 1 week. In the field, vector mortality in association with deltamethrin treatment was detected only with CBTs and only immediately after the treatment (OR 0.25, 95% CI: 0.13-0.52). Entomological sampling with CBTs highlights that targeting cattle for mosquito control has potential since it would not only target naturally zoophilic malaria vectors but also

Serum laminin in malaria.

PubMed Central

Wenisch, C; Graninger, W; Viravan, C; Looareesuwan, S; Parschalk, B; Wernsdorfer, W

1994-01-01

AIM--To determine serum laminin concentrations in patients with uncomplicated Plasmodium falciparum malaria. METHODS--An enzyme linked immunosorbent assay (ELISA) was used to determine serum laminin concentrations in 54 patients with acute uncomplicated P falciparum malaria during and after treatment, and in 17 control subjects in Bangkok, Thailand. RESULTS--Raised concentrations of soluble laminin were observed in patients (mean (SD) concentration 628 (225) ng/ml), compared with normal controls (490 (116) ng/ml), during the acute phase of the disease. During treatment, serum laminin concentrations decreased and returned to normal within three days. Serum laminin concentrations were correlated with parasite counts before treatment, and with the serum concentration of soluble intercellular adhesion molecule-1 (ICAM-1), soluble E-selectin, and soluble tumour necrosis factor receptor at 55 kilodaltons. CONCLUSIONS--These findings are compatible with an increased production or release of laminin in P falciparum malaria, which could indicate a role for the subendothelial basement membrane in the pathogenesis of the disease. PMID:7525659

[Links and effects of globalization on social and economic organization and malaria prevalence in the Coastal Region of Livingston, Guatemala].

PubMed

Nelson, Caro Méndez

2007-01-01

As a result of Guatemala's growing involvement in international markets and policies favoring industrial and export-oriented efforts, the population has experienced substantial changes in its economic and social organization, with consequences for the health and well-being of marginal groups. The article discusses various links between global processes, national policies and priorities, social and economic strategies, and malaria prevalence, with the Coastal Region of Livingston, Guatemala as the case study carried out between 2001 and 2003.

Rabies and African wild dogs in Kenya.

PubMed

Kat, P W; Alexander, K A; Smith, J S; Munson, L

1995-11-22

Three packs of African wild dogs (Lycaon pictus) ranging to the north of the Masai Mara National Reserve in southwestern Kenya were monitored from 1988 to 1990. During a six week period (August 2-September 14, 1989), 21 of 23 members of one of these packs died. Histological examination of two brain samples revealed eosinophilic intracytoplasmic inclusions (Negri bodies), supporting a diagnosis of rabies viral encephalitis. An additional brain sample tested positive for rabies with a fluorescent antibody test. Nucleotide sequence of the rabies viral N and G genes from isolates of four African wild dogs (including an individual from Tanzania) indicated that infection was with a viral variant common among domestic dogs in Kenya and Tanzania. A hypothesis linking African wild dog rabies deaths to researcher handling is evaluated and considered implausible.

Effect of malaria transmission reduction by insecticide-treated bed nets (ITNs) on the genetic diversity of Plasmodium falciparum merozoite surface protein (MSP-1) and circumsporozoite (CSP) in western Kenya.

PubMed

Kariuki, Simon K; Njunge, James; Muia, Ann; Muluvi, Geofrey; Gatei, Wangeci; Ter Kuile, Feiko; Terlouw, Dianne J; Hawley, William A; Phillips-Howard, Penelope A; Nahlen, Bernard L; Lindblade, Kim A; Hamel, Mary J; Slutsker, Laurence; Shi, Ya Ping

2013-08-27

Although several studies have investigated the impact of reduced malaria transmission due to insecticide-treated bed nets (ITNs) on the patterns of morbidity and mortality, there is limited information on their effect on parasite diversity. Sequencing was used to investigate the effect of ITNs on polymorphisms in two genes encoding leading Plasmodium falciparum vaccine candidate antigens, the 19 kilodalton blood stage merozoite surface protein-1 (MSP-1(19kDa)) and the Th2R and Th3R T-cell epitopes of the pre-erythrocytic stage circumsporozoite protein (CSP) in a large community-based ITN trial site in western Kenya. The number and frequency of haplotypes as well as nucleotide and haplotype diversity were compared among parasites obtained from children <5 years old prior to the introduction of ITNs (1996) and after 5 years of high coverage ITN use (2001). A total of 12 MSP-1(19kDa) haplotypes were detected in 1996 and 2001. The Q-KSNG-L and E-KSNG-L haplotypes corresponding to the FVO and FUP strains of P. falciparum were the most prevalent (range 32-37%), with an overall haplotype diversity of > 0.7. No MSP-1(19kDa) 3D7 sequence-types were detected in 1996 and the frequency was less than 4% in 2001. The CSP Th2R and Th3R domains were highly polymorphic with a total of 26 and 14 haplotypes, respectively detected in 1996 and 34 and 13 haplotypes in 2001, with an overall haplotype diversity of > 0.9 and 0.75 respectively. The frequency of the most predominant Th2R and Th3R haplotypes was 14 and 36%, respectively. The frequency of Th2R and Th3R haplotypes corresponding to the 3D7 parasite strain was less than 4% at both time points. There was no significant difference in nucleotide and haplotype diversity in parasite isolates collected at both time points. High diversity in these two genes has been maintained overtime despite marked reductions in malaria transmission due to ITNs use. The frequency of 3D7 sequence-types was very low in this area. These findings provide

A cross-sectional study of the availability and price of anti-malarial medicines and malaria rapid diagnostic tests in private sector retail drug outlets in rural Western Kenya, 2013.

PubMed

Kioko, Urbanus; Riley, Christina; Dellicour, Stephanie; Were, Vincent; Ouma, Peter; Gutman, Julie; Kariuki, Simon; Omar, Ahmeddin; Desai, Meghna; Buff, Ann M

2016-07-12

Although anti-malarial medicines are free in Kenyan public health facilities, patients often seek treatment from private sector retail drug outlets. In mid-2010, the Affordable Medicines Facility-malaria (AMFm) was introduced to make quality-assured artemisinin-based combination therapy (ACT) accessible and affordable in private and public sectors. Private sector retail drug outlets stocking anti-malarial medications within a surveillance area of approximately 220,000 people in a malaria perennial high-transmission area in rural western Kenya were identified via a census in September 2013. A cross-sectional study was conducted in September-October 2013 to determine availability and price of anti-malarial medicines and malaria rapid diagnostic tests (RDTs) in drug outlets. A standardized questionnaire was administered to collect drug outlet and personnel characteristics and availability and price of anti-malarials and RDTs. Of 181 drug outlets identified, 179 (99 %) participated in the survey. Thirteen percent were registered pharmacies, 25 % informal drug shops, 46 % general shops, 13 % homesteads and 2 % other. One hundred sixty-five (92 %) had at least one ACT type: 162 (91 %) had recommended first-line artemether-lumefantrine (AL), 22 (12 %) had recommended second-line dihydroartemisinin-piperaquine (DHA-PPQ), 85 (48 %) had sulfadoxine-pyrimethamine (SP), 60 (34 %) had any quinine (QN) formulation, and 14 (8 %) had amodiaquine (AQ) monotherapy. The mean price (range) of an adult treatment course for AL was $1.01 ($0.35-4.71); DHA-PPQ was $4.39 ($0.71-7.06); QN tablets were $2.24 ($0.12-4.71); SP was $0.62 ($0.24-2.35); AQ monotherapy was $0.42 ($0.24-1.06). The mean AL price with or without the AMFm logo did not differ significantly ($1.01 and 1.07, respectively; p = 0.45). Only 17 (10 %) drug outlets had RDTs; 149 (84 %) never stocked RDTs. The mean RDT price was $0.92 ($0.24-2.35). Most outlets never stocked RDTs; therefore, testing prior to

Malaria in the WHO Southeast Asia region.

PubMed

Kondrashin, A V

1992-09-01

Malaria endemic countries in the southeast Asia region include Bangladesh, Bhutan, India, Indonesia, Maldives, Myanmar, Nepal, Sri Lanka, and Thailand. Population movement and rapid urbanization, both largely caused by unemployment, and environmental deterioration change the malaria pattern. They also increase the incidence of drug-resistant malaria, especially resistance to 4-aminoquinolines. In India, Plasmodium falciparum is linked to the density and distribution of tribals, and, in southern Thailand, rubber tappers have the highest malaria incidence rate (46.29%). Since the population is young and the young are highly sensitive to malaria infection, the region has low community immunity. High malaria priority areas are forests, forested hills, forest fringe areas, developmental project sites, and border areas. High risk groups include infants, young children, pregnant women, and mobile population groups. Malaria incidence is between 2.5-2.8 million cases, and the slide positivity rate is about 3%. P. falciparum constitutes 40% for all malaria cases. In 1988 in India, there were 222 malaria deaths. Malaria is the 7th most common cause of death in Thailand. 3 of the 19 Anopheline species are resistant to at least 1 insecticide, particularly DDT. Posteradication epidemics surfaced in the mid-1970s. Malaria control programs tend to use the primary health care and integration approach to malaria control. Antiparasite measures range from a single-dose of an antimalarial to mass drug administration. Residual spraying continues to be the main strategy of vector control. Some other vector control measures are fish feeding on mosquito larvae, insecticide impregnated mosquito nets, and repellents. Control programs also have health education activities. India allocates the highest percentage of its total health budget to malaria control (21.54%). Few malariology training programs exist in the region. Slowly processed surveillance data limit the countries' ability to

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.

Lack of patient risk counselling and a broader provider training affect malaria control in remote Somalia Kenya border: Qualitative assessment.

PubMed

Asgary, Ramin; Grigoryan, Zoya; Naderi, Ramesh; Allan, Richard

2012-01-01

Effectiveness of providing health education solely via mass media and the providers' targeted training in malaria control needs further exploration. During pre-epidemic season, we conducted a qualitative study of 40 providers and community leaders using focus groups, comprehensive semi-structured interviews and consultation observations. Interviews were transcribed, coded and analysed for major themes. Community leaders believe that they can acquire malaria from contaminated water, animal products, air or garbage. Consequently, they under-utilise bed nets and other protective measures due to perceived continued exposure to other potential malaria sources. Practitioners do not provide individualised health counselling and risk assessment to patients during sick visits, leading to a range of misconceptions about malaria based on limited knowledge from rumours and mass media, and a strong belief in the curative power of traditional medicine. Providers overdiagnose malaria clinically and underutilise available tests due to time constraints, and the lack of training and resources to correctly diagnose other illnesses. Subsequently, misdiagnoses lead them to question the efficacy of recommended treatments. Promoting counselling during clinical encounters to address patient misconception and change risky behaviour is warranted. Wider-ranging ongoing training could enable providers to properly diagnose and manage differential diagnoses to manage malaria better.

Oceanic influence on seasonal malaria outbreaks over Senegal and Sahel. Predictability using S4CAST model

NASA Astrophysics Data System (ADS)

Diouf, Ibrahima; Deme, Abdoulaye; Rodriguez-Fonseca, Belen; Suárez-Moreno, Roberto; Cisse, Moustapha; Ndione, Jacques-André; Thierno Gaye, Amadou

2014-05-01

Senegal and, in general, West African regions are affected by important outbreaks of diseases with destructive consequences for human population, livestock and country's economy. The vector-borne diseases such as mainly malaria, Rift Valley Fever and dengue are affected by the interanual to decadal variability of climate. Analysis of the spatial and temporal variability of climate parameters and associated oceanic patterns is important in order to assess the climate impact on malaria transmission. In this study, the approach developed to study the malaria-climate link is predefined by the QWeCI project (Quantifying Weather and Climate Impacts on Health in Developing Countries). Preliminary observations and simulations results over Senegal Ferlo region, confirm that the risk of malaria transmission is mainly linked to climate parameters such as rainfall, temperature and relative humidity; and a lag of one to two months between the maximum of malaria and the maximum of climate parameters as rainfall is observed. As climate variables are able to be predicted from oceanic SST variability in remote regions, this study explores seasonal predictability of malaria incidence outbreaks from previous sea surface temperatures conditions in different ocean basins. We have found causal or coincident relationship between El Niño and malaria parameters by coupling LMM UNILIV malaria model and S4CAST statistiscal model with the aim of predicting the malaria parameters with more than 6 months in advance. In particular, El Niño is linked to an important decrease of the number of mosquitoes and the malaria incidence. Results from this research, after assessing the seasonal malaria parameters, are expected to be useful for decision makers to better access to climate forecasts and application on health in the framework of rolling back malaria transmission.

Age-structured gametocyte allocation links immunity to epidemiology in malaria parasites.

PubMed

Paul, Richard E; Bonnet, Sarah; Boudin, Christian; Tchuinkam, Timoleon; Robert, Vincent

2007-09-12

Despite a long history of attempts to model malaria epidemiology, the over-riding conclusion is that a detailed understanding of host-parasite interactions leading to immunity is required. It is still not known what governs the duration of an infection and how within-human parasite dynamics relate to malaria epidemiology. Immunity to Plasmodium falciparum develops slowly and requires repeated exposure to the parasite, which thus generates age-structure in the host-parasite interaction. An age-structured degree of immunity would present the parasite with humans of highly variable quality. Evolutionary theory suggests that natural selection will mould adaptive phenotypes that are more precise (less variant) in "high quality" habitats, where lifetime reproductive success is best. Variability in malaria parasite gametocyte density is predicted to be less variable in those age groups who best infect mosquitoes. Thus, the extent to which variation in gametocyte density is a simple parasite phenotype reflecting the complex within-host parasite dynamics is addressed. Gametocyte densities and corresponding infectiousness to mosquitoes from published data sets and studies in both rural and urban Cameroon are analysed. The mean and variation in gametocyte density according to age group are considered and compared with transmission success (proportion of mosquitoes infected). Across a wide range of settings endemic for malaria, the age group that infected most mosquitoes had the least variation in gametocyte density, i.e. there was a significant relationship between the variance rather than the mean gametocyte density and age-specific parasite transmission success. In these settings, the acquisition of immunity over time was evident as a decrease in asexual parasite densities with age. By contrast, in an urban setting, there were no such age-structured relationships either with variation in gametocyte density or asexual parasite density. Gametocyte production is seemingly

Malaria

MedlinePlus

Quartan malaria; Falciparum malaria; Biduoterian fever; Blackwater fever; Tertian malaria; Plasmodium ... Malaria is caused by a parasite that is passed to humans by the bite of infected anopheles ...

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.

Ecologists can enable communities to implement malaria vector control in Africa

PubMed Central

Mukabana, W Richard; Kannady, Khadija; Kiama, G Michael; Ijumba, Jasper N; Mathenge, Evan M; Kiche, Ibrahim; Nkwengulila, Gamba; Mboera, Leonard; Mtasiwa, Deo; Yamagata, Yoichi; van Schayk, Ingeborg; Knols, Bart GJ; Lindsay, Steven W; de Castro, Marcia Caldas; Mshinda, Hassan; Tanner, Marcel; Fillinger, Ulrike; Killeen, Gerry F

2006-01-01

Background Integrated vector management (IVM) for malaria control requires ecological skills that are very scarce and rarely applied in Africa today. Partnerships between communities and academic ecologists can address this capacity deficit, modernize the evidence base for such approaches and enable future scale up. Methods Community-based IVM programmes were initiated in two contrasting settings. On Rusinga Island, Western Kenya, community outreach to a marginalized rural community was achieved by University of Nairobi through a community-based organization. In Dar es Salaam, Tanzania, Ilala Municipality established an IVM programme at grassroots level, which was subsequently upgraded and expanded into a pilot scale Urban Malaria Control Programme with support from national academic institutes. Results Both programmes now access relevant expertise, funding and policy makers while the academic partners benefit from direct experience of community-based implementation and operational research opportunities. The communities now access up-to-date malaria-related knowledge and skills for translation into local action. Similarly, the academic partners have acquired better understanding of community needs and how to address them. Conclusion Until sufficient evidence is provided, community-based IVM remains an operational research activity. Researchers can never directly support every community in Africa so community-based IVM strategies and tactics will need to be incorporated into undergraduate teaching programmes to generate sufficient numbers of practitioners for national scale programmes. Academic ecologists at African institutions are uniquely positioned to enable the application of practical environmental and entomological skills for malaria control by communities at grassroots level and should be supported to fulfil this neglected role. PMID:16457724

Physical access to health facilities and contraceptive use in Kenya: evidence from the 2008-2009 Kenya Demographic and Health Survey.

PubMed

Ettarh, Remare R; Kyobutungi, Catherine

2012-09-01

The objective of the study was to determine the spatial variation in modern contraceptive use and unmet need for family planning across the counties of Kenya and to examine whether the spatial patterns were associated with inequalities in physical access to health facilities. Data were obtained from the 2008-2009 Kenya Demographic and Health Survey and linked to the location of health facilities in the country. Multivariate logistic regression was used to examine the influence of distance to the nearest health facility and health facility density, in addition to other covariates, on modern contraceptive use and unmet need. Overall, the prevalence of modern contraceptive use and unmet need among women aged 15-49 in Kenya was 42.1% and 19.7% respectively. Among the respondents who lived more than 5 km from the nearest health facility modern contraceptive use was significantly less likely compared to women resident 5 km or less from the nearest health facility. Women from counties with higher health facility density were 53% more likely to use modern contraceptives compared to women in counties with low health facility density. Distance and health facility density in the county were not significantly associated with unmet need. Physical access to health facilities is an important determinant of modern contraceptive use and unmet need in Kenya. Strategies should be developed in underserved counties to mitigate the challenge of distance to health facilities, such as delivering services by outreach and mobile facilities.

Malaria, Leishmaniasis and Shistosomiasis Vector Ecology, Transmission, Immunology and Prophylaxis in Kenya

DTIC Science & Technology

1994-01-27

medium supplemented with 20% fetal bovine serum, 250 ug/ml streptomycin, 250 U/ml penicillin , and 500 KEMRI Final Report DAMD17-87-G-7016 & DAMD17-89-Z...Leishmania major in a Kenyan Patient: Clinical Description and Parasite Characterization Larry Hendricks , Y.B. Mebrahtu, P.G. Lawyer, R. Muigai, C. Oster, P...Adungo, F.K. Owaga, P.V. Perkins, L.D. Hendricks , and R.E. Whitmire. Attack Rates of Malaria in School Children in The Siaya and Kisumu Districts, Nyanza

Simulating malaria transmission in the current and future climate of West Africa

NASA Astrophysics Data System (ADS)

Yamana, T. K.; Bomblies, A.; Eltahir, E. A. B.

2015-12-01

Malaria transmission in West Africa is closely tied to climate, as rain fed water pools provide breeding habitat for the anopheles mosquito vector, and temperature affects the mosquito's ability to spread disease. We present results of a highly detailed, spatially explicit mechanistic modelling study exploring the relationships between the environment and malaria in the current and future climate of West Africa. A mechanistic model of human immunity was incorporated into an existing agent-based model of malaria transmission, allowing us to move beyond entomological measures such as mosquito density and vectorial capacity to analyzing the prevalence of the malaria parasite within human populations. The result is a novel modelling tool that mechanistically simulates all of the key processes linking environment to malaria transmission. Simulations were conducted across climate zones in West Africa, linking temperature and rainfall to entomological and epidemiological variables with a focus on nonlinearities due to threshold effects and interannual variability. Comparisons to observations from the region confirmed that the model provides a reasonable representation of the entomological and epidemiological conditions in this region. We used the predictions of future climate from the most credible CMIP5 climate models to predict the change in frequency and severity of malaria epidemics in West Africa as a result of climate change.

Bed net ownership in Kenya: the impact of 3.4 million free bed nets.

PubMed

Hightower, Allen; Kiptui, Rebecca; Manya, Ayub; Wolkon, Adam; Vanden Eng, Jodi Leigh; Hamel, Mary; Noor, Abdisalan; Sharif, Shahnaz K; Buluma, Robert; Vulule, John; Laserson, Kayla; Slutsker, Laurence; Akhwale, Willis

2010-06-24

In July and September 2006, 3.4 million long-lasting insecticide-treated bed nets (LLINs) were distributed free in a campaign targeting children 0-59 months old (CU5s) in the 46 districts with malaria in Kenya. A survey was conducted one month after the distribution to evaluate who received campaign LLINs, who owned insecticide-treated bed nets and other bed nets received through other channels, and how these nets were being used. The feasibility of a distribution strategy aimed at a high-risk target group to meet bed net ownership and usage targets is evaluated. A stratified, two-stage cluster survey sampled districts and enumeration areas with probability proportional to size. Handheld computers (PDAs) with attached global positioning systems (GPS) were used to develop the sampling frame, guide interviewers back to chosen households, and collect survey data. In targeted areas, 67.5% (95% CI: 64.6, 70.3%) of all households with CU5s received campaign LLINs. Including previously owned nets, 74.4% (95% CI: 71.8, 77.0%) of all households with CU5s had an ITN. Over half of CU5s (51.7%, 95% CI: 48.8, 54.7%) slept under an ITN during the previous evening. Nearly forty percent (39.1%) of all households received a campaign net, elevating overall household ownership of ITNs to 50.7% (95% CI: 48.4, 52.9%). The campaign was successful in reaching the target population, families with CU5s, the risk group most vulnerable to malaria. Targeted distribution strategies will help Kenya approach indicator targets, but will need to be combined with other strategies to achieve desired population coverage levels.

Quantifying malaria endemicity in Ethiopia through combined application of classical methods and enzyme-linked immunosorbent assay: an initial step for countries with low transmission initiating elimination programme.

PubMed

Birhanu, Zewdie; Yihdego, Yemane Ye-Ebiyo; Yewhalaw, Delenasaw

2018-04-04

In the context of reduced transmission of malaria, it is essential to re-evaluate and determine the level of transmission as it guides re-orientation of control measures which is appropriate to local disease epidemiology. However, little is known about level of malaria transmission in Ethiopia. The present study aimed to investigate the level of malaria transmission through combined application of classical methods and enzyme-linked immunosorbent assay (EIA) in low transmission settings of Ethiopia. This study was conducted in June 2016 on 763 apparently healthy children 2-9 years of age. Children were recruited from ten sites representing different malaria transmission settings in Ethiopia. Splenomegaly rate, infection rate and EIA antibody test were used to determine endemicity. The data were analysed using SPSS 21.0 and Stata 12.0. The overall prevalence of malaria parasitaemia was 2.49% (95% CI 1.38-3.59) and 2.36% (95% CI 1.28-3.44) as detected using rapid diagnostic test and microscopy, respectively. Plasmodium falciparum accounted for 62.63% of the infections. The prevalence of parasitaemia significantly varied by altitude and localities; the highest (5.8%) in areas below 1500 m above sea level. Overall, splenomegaly rate was 1.70% (95% CI 0.78-0.2.66%), making the overall malaria transmission hypoendemic. Infection rate was higher among males (2.7%), but rate of splenomegaly was higher in females. Incongruent with spleen rate and parasitaemia, EIA showed a higher level of cumulative exposure to malaria with spatially localized and highly heterogeneous transmission. Overall, 126 (18.75%, 95% CI 15.79-21.71) of the children were positive for total malaria antibodies with significant variations with altitude, age and sex; the higher in areas of < 1500 m asl (25.8%), children ≥ 5 years (22.1%) and among males (20.9%). Splenomegaly and parasitaemia are not good measures to show variations in the levels of malaria transmission in reduced and/or low

Information Systems to Support Surveillance for Malaria Elimination

PubMed Central

Ohrt, Colin; Roberts, Kathryn W.; Sturrock, Hugh J. W.; Wegbreit, Jennifer; Lee, Bruce Y.; Gosling, Roly D.

2015-01-01

Robust and responsive surveillance systems are critical for malaria elimination. The ideal information system that supports malaria elimination includes: rapid and complete case reporting, incorporation of related data, such as census or health survey information, central data storage and management, automated and expert data analysis, and customized outputs and feedback that lead to timely and targeted responses. Spatial information enhances such a system, ensuring cases are tracked and mapped over time. Data sharing and coordination across borders are vital and new technologies can improve data speed, accuracy, and quality. Parts of this ideal information system exist and are in use, but have yet to be linked together coherently. Malaria elimination programs should support the implementation and refinement of information systems to support surveillance and response and ensure political and financial commitment to maintain the systems and the human resources needed to run them. National malaria programs should strive to improve the access and utility of these information systems and establish cross-border data sharing mechanisms through the use of standard indicators for malaria surveillance. Ultimately, investment in the information technologies that support a timely and targeted surveillance and response system is essential for malaria elimination. PMID:26013378

Electrification pathways for Kenya-linking spatial electrification analysis and medium to long term energy planning

NASA Astrophysics Data System (ADS)

Moksnes, Nandi; Korkovelos, Alexandros; Mentis, Dimitrios; Howells, Mark

2017-09-01

In September 2015 UN announced 17 Sustainable Development goals (SDG) from which goal number 7 envisions universal access to modern energy services for all by 2030. In Kenya only about 46% of the population currently has access to electricity. This paper analyses hypothetical scenarios, and selected implications, investigating pathways that would allow the country to reach its electrification targets by 2030. Two modelling tools were used for the purposes of this study, namely OnSSET and OSeMOSYS. The tools were soft-linked in order to capture both the spatial and temporal dynamics of their nature. Two electricity demand scenarios were developed representing low and high end user consumption goals respectively. Indicatively, results show that geothermal, coal, hydro and natural gas would consist the optimal energy mix for the centralized national grid. However, in the case of the low demand scenario a high penetration of stand-alone systems is evident in the country, reaching out to approximately 47% of the electrified population. Increasing end user consumption leads to a shift in the optimal technology mix, with higher penetration of mini-grid technologies and grid extension.

Esophageal cancer in Kenya

PubMed Central

Odera, Joab Otieno; Odera, Elizabeth; Githang’a, Jessie; Walong, Edwin Oloo; Li, Fang; Xiong, Zhaohui; Chen, Xiaoxin Luke

2017-01-01

Kenya belongs to a high incidence region known as Africa’s esophageal cancer (EC) corridor. It has one of the highest incidence rates of EC worldwide, but research on EC in Kenya has gone highly unnoticed. EC in Kenya is unique in its high percentage of young cases (< 30 years of age). In this review, we show the current status of EC in the country. We mainly focus on significant risk factors such as alcohol drinking, genetic factors, malnutrition and hot food/drink. Future directions in the study and prevention of EC in Kenya are also discussed. PMID:29082268

Resisting and tolerating P. falciparum in pregnancy under different malaria transmission intensities.

PubMed

Ndam, Nicaise Tuikue; Mbuba, Emmanuel; González, Raquel; Cisteró, Pau; Kariuki, Simon; Sevene, Esperança; Rupérez, María; Fonseca, Ana Maria; Vala, Anifa; Maculuve, Sonia; Jiménez, Alfons; Quintó, Llorenç; Ouma, Peter; Ramharter, Michael; Aponte, John J; Nhacolo, Arsenio; Massougbodji, Achille; Briand, Valerie; Kremsner, Peter G; Mombo-Ngoma, Ghyslain; Desai, Meghna; Macete, Eusebio; Cot, Michel; Menéndez, Clara; Mayor, Alfredo

2017-07-17

Resistance and tolerance to Plasmodium falciparum can determine the progression of malaria disease. However, quantitative evidence of tolerance is still limited. We investigated variations in the adverse impact of P. falciparum infections among African pregnant women under different intensities of malaria transmission. P. falciparum at delivery was assessed by microscopy, quantitative PCR (qPCR) and placental histology in 946 HIV-uninfected and 768 HIV-infected pregnant women from Benin, Gabon, Kenya and Mozambique. Resistance was defined by the proportion of submicroscopic infections and the levels of anti-parasite antibodies quantified by Luminex, and tolerance by the relationship of pregnancy outcomes with parasite densities at delivery. P. falciparum prevalence by qPCR in peripheral and/or placental blood of HIV-uninfected Mozambican, Gabonese and Beninese women at delivery was 6% (21/340), 11% (28/257) and 41% (143/349), respectively. The proportion of peripheral submicroscopic infections was higher in Benin (83%) than in Mozambique (60%) and Gabon (55%; P = 0.033). Past or chronic placental P. falciparum infection was associated with an increased risk of preterm birth in Mozambican newborns (OR = 7.05, 95% CI 1.79 to 27.82). Microscopic infections were associated with reductions in haemoglobin levels at delivery among Mozambican women (-1.17 g/dL, 95% CI -2.09 to -0.24) as well as with larger drops in haemoglobin levels from recruitment to delivery in Mozambican (-1.66 g/dL, 95% CI -2.68 to -0.64) and Gabonese (-0.91 g/dL, 95% CI -1.79 to -0.02) women. Doubling qPCR-peripheral parasite densities in Mozambican women were associated with decreases in haemoglobin levels at delivery (-0.16 g/dL, 95% CI -0.29 to -0.02) and increases in the drop of haemoglobin levels (-0.29 g/dL, 95% CI -0.44 to -0.14). Beninese women had higher anti-parasite IgGs than Mozambican women (P < 0.001). No difference was found in the proportion of submicroscopic

Role of Activins in Hepcidin Regulation during Malaria.

PubMed

Spottiswoode, Natasha; Armitage, Andrew E; Williams, Andrew R; Fyfe, Alex J; Biswas, Sumi; Hodgson, Susanne H; Llewellyn, David; Choudhary, Prateek; Draper, Simon J; Duffy, Patrick E; Drakesmith, Hal

2017-12-01

Epidemiological observations have linked increased host iron with malaria susceptibility, and perturbed iron handling has been hypothesized to contribute to the potentially life-threatening anemia that may accompany blood-stage malaria infection. To improve our understanding of these relationships, we examined the pathways involved in regulation of the master controller of iron metabolism, the hormone hepcidin, in malaria infection. We show that hepcidin upregulation in Plasmodium berghei murine malaria infection was accompanied by changes in expression of bone morphogenetic protein (BMP)/sons of mothers against decapentaplegic (SMAD) pathway target genes, a key pathway involved in hepcidin regulation. We therefore investigated known agonists of the BMP/SMAD pathway and found that Bmp gene expression was not increased in infection. In contrast, activin B, which can signal through the BMP/SMAD pathway and has been associated with increased hepcidin during inflammation, was upregulated in the livers of Plasmodium berghei -infected mice; hepatic activin B was also upregulated at peak parasitemia during infection with Plasmodium chabaudi Concentrations of the closely related protein activin A increased in parallel with hepcidin in serum from malaria-naive volunteers infected in controlled human malaria infection (CHMI) clinical trials. However, antibody-mediated neutralization of activin activity during murine malaria infection did not affect hepcidin expression, suggesting that these proteins do not stimulate hepcidin upregulation directly. In conclusion, we present evidence that the BMP/SMAD signaling pathway is perturbed in malaria infection but that activins, although raised in malaria infection, may not have a critical role in hepcidin upregulation in this setting. Copyright © 2017 Spottiswoode et al.

Testing a multi-malaria-model ensemble against 30 years of data in the Kenyan highlands

PubMed Central

2014-01-01

Background Multi-model ensembles could overcome challenges resulting from uncertainties in models’ initial conditions, parameterization and structural imperfections. They could also quantify in a probabilistic way uncertainties in future climatic conditions and their impacts. Methods A four-malaria-model ensemble was implemented to assess the impact of long-term changes in climatic conditions on Plasmodium falciparum malaria morbidity observed in Kericho, in the highlands of Western Kenya, over the period 1979–2009. Input data included quality controlled temperature and rainfall records gathered at a nearby weather station over the historical periods 1979–2009 and 1980–2009, respectively. Simulations included models’ sensitivities to changes in sets of parameters and analysis of non-linear changes in the mean duration of host’s infectivity to vectors due to increased resistance to anti-malarial drugs. Results The ensemble explained from 32 to 38% of the variance of the observed P. falciparum malaria incidence. Obtained R2-values were above the results achieved with individual model simulation outputs. Up to 18.6% of the variance of malaria incidence could be attributed to the +0.19 to +0.25°C per decade significant long-term linear trend in near-surface air temperatures. On top of this 18.6%, at least 6% of the variance of malaria incidence could be related to the increased resistance to anti-malarial drugs. Ensemble simulations also suggest that climatic conditions have likely been less favourable to malaria transmission in Kericho in recent years. Conclusions Long-term changes in climatic conditions and non-linear changes in the mean duration of host’s infectivity are synergistically driving the increasing incidence of P. falciparum malaria in the Kenyan highlands. User-friendly, online-downloadable, open source mathematical tools, such as the one presented here, could improve decision-making processes of local and regional health authorities. PMID

The fertility decline in Kenya.

PubMed

Robinson, W C; Harbison, S F

1995-01-01

In Sub-Saharan Africa Kenya is a prime example of a country experiencing a rapid decline in fertility and greater contraceptive prevalence. These changes have occurred since 1980 when fertility was high at 8.0 children per woman. In 1993 the total fertility rate (TFR) was 5.4, and the growth rate declined to about 2.0%. This transition is swifter than any country in contemporary Asia or historical Europe. The likely projection for Kenya is attainment of replacement level fertility during the 2020s and a leveling of population at about 100 million persons. Fertility has declined the most in urban areas and central and eastern regions. Bongaarts' proximate determinants (TFR, total marital fertility rate, total natural marital fertility rate, and total fecundity) are reduced to the proportion of currently married women using contraception, the proportion in lactational nonfecund status, and the proportion currently married. Actual fertility change is accounted for by total fertility change of 3.0 children. Lactational infecundability accounts for 0.5 potential births, and changes in marital fertility account for 1.0 reduced births per woman. About 70% of fertility reduction is accounted for by contraception and abortion. During 1977-78 80% of fertility control was due to lactational nonfecundity, 10% to nonmarriage, and 10% to contraception. In 1993 lactational nonfecundity accounted for 50% of the reduction, nonmarriage for 20%, and abortion about 30%. Future fertility is expected to be dependent on contraceptive prevalence. Kenya has experienced the Coale paradigm of preconditions necessary for demographic transition (willing, ready, and able). High fertility in Africa is not intractable. Creating the change in attitudes that leads to readiness is linked to education, health, and exposure to modernizing media and urban lifestyles. The public sector family planning program in Kenya has created the opportunity for access and availability of contraception. The key

Monitoring health systems readiness and inpatient malaria case-management at Kenyan county hospitals.

PubMed

Zurovac, Dejan; Machini, Beatrice; Kiptui, Rebecca; Memusi, Dorothy; Amboko, Beatrice; Kigen, Samuel; Njiri, Patricia; Waqo, Ejersa

2018-05-29

Change of severe malaria treatment policy from quinine to artesunate, a major malaria control advance in Africa, is compromised by scarce data to monitor policy translation into practice. In Kenya, hospital surveys were implemented to monitor health systems readiness and inpatient malaria case-management. All 47 county referral hospitals were surveyed in February and October 2016. Data collection included hospital assessments, interviews with inpatient health workers and retrospective review of patients' admission files. Analysis included 185 and 182 health workers, and 1162 and 1224 patients admitted with suspected malaria, respectively, in all 47 hospitals. Cluster-adjusted comparisons of the performance indicators with exploratory stratifications were performed. Malaria microscopy was universal during both surveys. Artesunate availability increased (63.8-85.1%), while retrospective stock-outs declined (46.8-19.2%). No significant changes were observed in the coverage of artesunate trained (42.2% vs 40.7%) and supervised health workers (8.7% vs 12.8%). The knowledge about treatment policy improved (73.5-85.7%; p = 0.002) while correct artesunate dosing knowledge increased for patients < 20 kg (42.7-64.6%; p < 0.001) and > 20 kg (70.3-80.8%; p = 0.052). Most patients were tested on admission (88.6% vs 92.1%; p = 0.080) while repeated malaria testing was low (5.2% vs 8.1%; p = 0.034). Artesunate treatment for confirmed severe malaria patients significantly increased (69.9-78.7%; p = 0.030). No changes were observed in artemether-lumefantrine treatment for non-severe test positive patients (8.0% vs 8.8%; p = 0.796). Among test negative patients, increased adherence to test results was observed for non-severe (68.6-78.0%; p = 0.063) but not for severe patients (59.1-62.1%; p = 0.673). Overall quality of malaria case-management improved (48.6-56.3%; p = 0.004), both for children (54.1-61.5%; p = 0.019) and adults

Malaria knowledge and treatment adherence in a Brazilian Amazon community.

PubMed

Souza, Taisa Guimarães de; Reiners, Annelita Almeida Oliveira; Azevedo, Rosemeiry Capriata de Souza; Fontes, Cor Jesus Fernandes; Ferreira, Rita Graziela; Do Carmo, Priscilla Uiara

2016-11-24

Malaria remains an important public health problem despite recent scientific breakthroughs regarding knowledge about malaria and treatment strategies. The objective of this study was to analyze malaria patients' knowledge about the disease, its treatment and prevention, linking it to drug treatment adherence. A descriptive, cross-sectional, epidemiological survey study was conducted in the district of Três Fronteiras-MT. The study included 618 individuals who were interviewed and examined for Plasmodium infection. Of the 52 patients diagnosed with malaria, 27 were visited at home for an interview about malaria knowledge and treatment adherence. Treatment adherence was evaluated by self-reports and drug conference. A total of 18 patients had satisfactory knowledge (66.6%) and 9 were evaluated as having unsatisfactory knowledge (33.4%) about malaria. Of the 27 malaria patients, 21 (77.8%) reported having taken all the medication as prescribed, in the correct period of time and dosage, and had no medication tablets remaining. The majority (72.2%) of patients who had satisfactory knowledge, as well as the majority (88.8%) of those who had unsatisfactory knowledge, adhered to the malaria treatment. This study revealed a high proportion of patients with satisfactory prior knowledge about malaria and revealed that this knowledge was not related to disease treatment adherence. These results have implications for planning strategies for malaria control in the region and could contribute to the reduction in the cases of non-adherence to malaria treatment.

Potential impact of global climate change on malaria risk

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

Martens, W.J.M.; Rotmans, J.; Niessen, L.W.

The biological activity and geographic distribution of the malarial parasite and its vector are sensitive to climatic influences, especially temperature and precipitation. We have incorporated General Circulation Model-based scenarios of anthropogenic global climate change in an integrated linked-system model for predicting changes in malaria epidemic potential in the next century. The concept of the disability-adjusted life years is included to arrive at a single measure of the effect of anthropogenic climate change on the health impact of malaria. Assessment of the potential impact of global climate change on the incidence of malaria suggests a widespread increase of risk due tomore » expansion of the areas suitable for malaria transmission. This predicted increase is most pronounced at the borders of endemic malaria areas and at higher altitudes within malarial areas. The incidence of infection is sensitive to climate changes in areas of Southeast Asia, South America, and parts of Africa where the disease is less endemic; in these regions the numbers of years of healthy life lost may increase significantly. However, the simulated changes in malaria risk must be interpreted on the basis of local environmental conditions, the effects of socioeconomic developments, and malaria control programs or capabilities. 33 refs., 5 figs., 1 tab.« less

Trends in bednet ownership and usage, and the effect of bednets on malaria hospitalization in the Kilifi Health and Demographic Surveillance System (KHDSS): 2008-2015.

PubMed

Kamau, Alice; Nyaga, Victoria; Bauni, Evasius; Tsofa, Benjamin; Noor, Abdisalan M; Bejon, Philip; Scott, J Anthony G; Hammitt, Laura L

2017-11-15

Use of bednets reduces malaria morbidity and mortality. In Kilifi, Kenya, there was a mass distribution of free nets to children < 5 years in 2006. In 2009, a new policy was implemented to offer bednets to pregnant women and children < 5 years free of charge. Nets were again distributed to children and adults through national mass campaigns in 2012 and 2015. We aimed to evaluate trends in bednet ownership and usage, and the effect of bednets on the incidence of malaria hospitalization in children < 5 years within the Kilifi Health and Demographic Surveillance System (KHDSS). Bednet ownership and usage were assessed during eight routine enumeration rounds of the KHDSS between 2008 and 2015. Malaria admissions (i.e. admissions to hospital with P. falciparum > 2500 parasitemia per μl) among children < 5 years were captured using a system of continuous vital registration that links admissions at Kilifi County Hospital to the KHDSS population register. Survival analysis was used to assess relative risk of hospitalization with malaria among children that reported using a bednet compared to those who did not. We observed 63% and 62% mean bednet ownership and usage, respectively, over the eight-survey period. Among children < 5 years, reported bednet ownership in October-December 2008 was 69% and in March-August 2009 was 73% (p < 0.001). An increase was also observed following the mass distribution campaigns in 2012 (62% in May-July 2012 vs 90% in May-October 2013, p < 0.001) and 2015 (68% in June-September 2015 vs 93% in October-November 2015, p < 0.001). Among children <5 years who reported using a net the night prior to the survey, the incidence of malaria hospitalization per 1000 child-years was 2.91 compared to 4.37 among those who did not (HR = 0.67, 95% CI: 0.52, 0.85 [p = 0.001]). On longitudinal surveillance, increasing bednet ownership and usage corresponded to mass distribution campaigns; however, this method of

Information systems to support surveillance for malaria elimination.

PubMed

Ohrt, Colin; Roberts, Kathryn W; Sturrock, Hugh J W; Wegbreit, Jennifer; Lee, Bruce Y; Gosling, Roly D

2015-07-01

Robust and responsive surveillance systems are critical for malaria elimination. The ideal information system that supports malaria elimination includes: rapid and complete case reporting, incorporation of related data, such as census or health survey information, central data storage and management, automated and expert data analysis, and customized outputs and feedback that lead to timely and targeted responses. Spatial information enhances such a system, ensuring cases are tracked and mapped over time. Data sharing and coordination across borders are vital and new technologies can improve data speed, accuracy, and quality. Parts of this ideal information system exist and are in use, but have yet to be linked together coherently. Malaria elimination programs should support the implementation and refinement of information systems to support surveillance and response and ensure political and financial commitment to maintain the systems and the human resources needed to run them. National malaria programs should strive to improve the access and utility of these information systems and establish cross-border data sharing mechanisms through the use of standard indicators for malaria surveillance. Ultimately, investment in the information technologies that support a timely and targeted surveillance and response system is essential for malaria elimination. © The American Society of Tropical Medicine and Hygiene.

Towards Free Day Secondary Schooling in Kenya: Exposing the Impediments

ERIC Educational Resources Information Center

Kamau Njoroge, John; Wambugu, Beth N.

2017-01-01

Secondary education provides a vital link between basic education and the world of work, on one hand, and further training on the other. It is therefore an important sub-sector of education in the preparation of human capital for development and provision of life opportunities. Secondary education in Kenya takes four years to complete, catering…

Spatiotemporal Bayesian networks for malaria prediction.

PubMed

Haddawy, Peter; Hasan, A H M Imrul; Kasantikul, Rangwan; Lawpoolsri, Saranath; Sa-Angchai, Patiwat; Kaewkungwal, Jaranit; Singhasivanon, Pratap

2018-01-01

Targeted intervention and resource allocation are essential for effective malaria control, particularly in remote areas, with predictive models providing important information for decision making. While a diversity of modeling technique have been used to create predictive models of malaria, no work has made use of Bayesian networks. Bayes nets are attractive due to their ability to represent uncertainty, model time lagged and nonlinear relations, and provide explanations. This paper explores the use of Bayesian networks to model malaria, demonstrating the approach by creating village level models with weekly temporal resolution for Tha Song Yang district in northern Thailand. The networks are learned using data on cases and environmental covariates. Three types of networks are explored: networks for numeric prediction, networks for outbreak prediction, and networks that incorporate spatial autocorrelation. Evaluation of the numeric prediction network shows that the Bayes net has prediction accuracy in terms of mean absolute error of about 1.4 cases for 1 week prediction and 1.7 cases for 6 week prediction. The network for outbreak prediction has an ROC AUC above 0.9 for all prediction horizons. Comparison of prediction accuracy of both Bayes nets against several traditional modeling approaches shows the Bayes nets to outperform the other models for longer time horizon prediction of high incidence transmission. To model spread of malaria over space, we elaborate the models with links between the village networks. This results in some very large models which would be far too laborious to build by hand. So we represent the models as collections of probability logic rules and automatically generate the networks. Evaluation of the models shows that the autocorrelation links significantly improve prediction accuracy for some villages in regions of high incidence. We conclude that spatiotemporal Bayesian networks are a highly promising modeling alternative for prediction

PGMS: A Case Study of Collecting PDA-Based Geo-Tagged Malaria-Related Survey Data

PubMed Central

Zhou, Ying; Lobo, Neil F.; Wolkon, Adam; Gimnig, John E.; Malishee, Alpha; Stevenson, Jennifer; Sulistyawati; Collins, Frank H.; Madey, Greg

2014-01-01

Using mobile devices, such as personal digital assistants (PDAs), smartphones, tablet computers, etc., to electronically collect malaria-related field data is the way for the field questionnaires in the future. This case study seeks to design a generic survey framework PDA-based geo-tagged malaria-related data collection tool (PGMS) that can be used not only for large-scale community-level geo-tagged electronic malaria-related surveys, but also for a wide variety of electronic data collections of other infectious diseases. The framework includes two parts: the database designed for subsequent cross-sectional data analysis and the customized programs for the six study sites (two in Kenya, three in Indonesia, and one in Tanzania). In addition to the framework development, we also present our methods used when configuring and deploying the PDAs to 1) reduce data entry errors, 2) conserve battery power, 3) field install the programs onto dozens of handheld devices, 4) translate electronic questionnaires into local languages, 5) prevent data loss, and 6) transfer data from PDAs to computers for future analysis and storage. Since 2008, PGMS has successfully accomplished quite a few surveys that recorded 10,871 compounds and households, 52,126 persons, and 17,100 bed nets from the six sites. These numbers are still growing. PMID:25048377

Low perception of malaria risk among the Ra-glai ethnic minority in south-central Vietnam: implications for forest malaria control.

PubMed

Peeters Grietens, Koen; Xuan, Xa Nguyen; Van Bortel, Wim; Duc, Thang Ngo; Ribera, Joan Muela; Ba Nhat, Truong; Van, Ky Pham; Le Xuan, Hung; D'Alessandro, Umberto; Erhart, Annette

2010-01-20

settings in the Greater Mekong sub-region implies that further success in malaria control will be linked to research into these specific socio-cultural contexts. Findings highlight the need for context sensitive malaria control policies; not only to reduce the local malaria burden but also to minimize the risk of malaria spreading to other areas where transmission has virtually ceased.

Low perception of malaria risk among the Ra-glai ethnic minority in south-central Vietnam: implications for forest malaria control

PubMed Central

2010-01-01

confinement of malaria to minority groups and settings in the Greater Mekong sub-region implies that further success in malaria control will be linked to research into these specific socio-cultural contexts. Findings highlight the need for context sensitive malaria control policies; not only to reduce the local malaria burden but also to minimize the risk of malaria spreading to other areas where transmission has virtually ceased. PMID:20089152

Climate impact on malaria in northern Burkina Faso.

PubMed

Tourre, Yves M; Vignolles, Cécile; Viel, Christian; Mounier, Flore

2017-11-27

The Paluclim project managed by the French Centre National d'Etudes Spatiales (CNES) found that total rainfall for a 3-month period is a confounding factor for the density of malaria vectors in the region of Nouna in the Sahel administrative territory of northern Burkina Faso. Following the models introduced in 1999 by Craig et al. and in 2003 by Tanser et al., a climate impact model for malaria risk (using different climate indices) was created. Several predictions of this risk at different temporal scales (i.e. seasonal, inter-annual and low-frequency) were assessed using this climate model. The main result of this investigation was the discovery of a significant link between malaria risk and low-frequency rainfall variability related to the Atlantic Multi-decadal Oscillation (AMO). This result is critical for the health information systems in this region. Knowledge of the AMO phases would help local authorities to organise preparedness and prevention of malaria, which is of particular importance in the climate change context.

Bed net ownership in Kenya: the impact of 3.4 million free bed nets

PubMed Central

2010-01-01

Background In July and September 2006, 3.4 million long-lasting insecticide-treated bed nets (LLINs) were distributed free in a campaign targeting children 0-59 months old (CU5s) in the 46 districts with malaria in Kenya. A survey was conducted one month after the distribution to evaluate who received campaign LLINs, who owned insecticide-treated bed nets and other bed nets received through other channels, and how these nets were being used. The feasibility of a distribution strategy aimed at a high-risk target group to meet bed net ownership and usage targets is evaluated. Methods A stratified, two-stage cluster survey sampled districts and enumeration areas with probability proportional to size. Handheld computers (PDAs) with attached global positioning systems (GPS) were used to develop the sampling frame, guide interviewers back to chosen households, and collect survey data. Results In targeted areas, 67.5% (95% CI: 64.6, 70.3%) of all households with CU5s received campaign LLINs. Including previously owned nets, 74.4% (95% CI: 71.8, 77.0%) of all households with CU5s had an ITN. Over half of CU5s (51.7%, 95% CI: 48.8, 54.7%) slept under an ITN during the previous evening. Nearly forty percent (39.1%) of all households received a campaign net, elevating overall household ownership of ITNs to 50.7% (95% CI: 48.4, 52.9%). Conclusions The campaign was successful in reaching the target population, families with CU5s, the risk group most vulnerable to malaria. Targeted distribution strategies will help Kenya approach indicator targets, but will need to be combined with other strategies to achieve desired population coverage levels. PMID:20576145

High Levels of Asymptomatic and Subpatent Plasmodium falciparum Parasite Carriage at Health Facilities in an Area of Heterogeneous Malaria Transmission Intensity in the Kenyan Highlands

PubMed Central

Stresman, Gillian H.; Stevenson, Jennifer C.; Ngwu, Nnenna; Marube, Elizabeth; Owaga, Chrispin; Drakeley, Chris; Bousema, Teun; Cox, Jonathan

2014-01-01

In endemic settings, health facility surveys provide a convenient approach to estimating malaria transmission intensity. Typically, testing for malaria at facilities is performed on symptomatic attendees, but asymptomatic infections comprise a considerable proportion of the parasite reservoir. We sampled individuals attending five health facilities in the western Kenyan highlands. Malaria prevalence by rapid diagnostic test (RDT) was 8.6–32.9% in the health facilities. Of all polymerase chain reaction-positive participants, 46.4% (95% confidence interval [95% CI] = 42.6–50.2%) of participants had infections that were RDT-negative and asymptomatic, and 55.9% of those infections consisted of multiple parasite clones as assessed by merozoite surface protein-2 genotyping. Subpatent infections were more common in individuals reporting the use of non-artemisinin–based antimalarials in the 2 weeks preceding the survey (odds ratio = 2.49, 95% CI = 1.04–5.92) compared with individuals not reporting previous use of antimalarials. We observed a large and genetically complex pool of subpatent parasitemia in the Kenya highlands that must be considered in malaria interventions. PMID:25331807

The Association of Parasitic Infections in Pregnancy and Maternal and Fetal Anemia: A Cohort Study in Coastal Kenya

PubMed Central

McClure, Elizabeth M.; Meshnick, Steven R.; Mungai, Peter; Malhotra, Indu; King, Christopher L.; Goldenberg, Robert L.; Hudgens, Michael G.; Siega-Riz, Anna Maria; Dent, Arlene E.

2014-01-01

Background Relative contribution of these infections on anemia in pregnancy is not certain. While measures to protect pregnant women against malaria have been scaling up, interventions against helminthes have received much less attention. In this study, we determine the relative impact of helminthes and malaria on maternal anemia. Methods A prospective observational study was conducted in coastal Kenya among a cohort of pregnant women who were recruited at their first antenatal care (ANC) visit and tested for malaria, hookworm, and other parasitic infections and anemia at enrollment. All women enrolled in the study received presumptive treatment with sulfadoxine-pyrimethamine, iron and multi-vitamins and women diagnosed with helminthic infections were treated with albendazole. Women delivering a live, term birth, were also tested for maternal anemia, fetal anemia and presence of infection at delivery. Principal Findings Of the 706 women studied, at the first ANC visit, 27% had moderate/severe anemia and 71% of women were anemic overall. The infections with highest prevalence were hookworm (24%), urogenital schistosomiasis (17%), trichuria (10%), and malaria (9%). In adjusted and unadjusted analyses, moderate/severe anemia at first ANC visit was associated with the higher intensities of hookworm and P. falciparum microscopy-malaria infections. At delivery, 34% of women had moderate/severe anemia and 18% of infants' cord hemoglobin was consistent with fetal anemia. While none of the maternal infections were significantly associated with fetal anemia, moderate/severe maternal anemia was associated with fetal anemia. Conclusions More than one quarter of women receiving standard ANC with IPTp for malaria had moderate/severe anemia in pregnancy and high rates of parasitic infection. Thus, addressing the role of co-infections, such as hookworm, as well as under-nutrition, and their contribution to anemia is needed. PMID:24587473

Challenges of establishing the correct diagnosis of outbreaks of acute febrile illnesses in Africa: the case of a likely Brucella outbreak among nomadic pastoralists, northeast Kenya, March-July 2005.

PubMed

Ari, Mary D; Guracha, Argata; Fadeel, Moustafa Abdel; Njuguna, Charles; Njenga, M Kariuki; Kalani, Rosalia; Abdi, Hassan; Warfu, Osman; Omballa, Victor; Tetteh, Christopher; Breiman, Robert F; Pimentel, Guillermo; Feikin, Daniel R

2011-11-01

An outbreak of acute febrile illness was reported among Somali pastoralists in remote, arid Northeast Kenya, where drinking raw milk is common. Blood specimens from 12 patients, collected mostly in the late convalescent phase, were tested for viral, bacterial, and parasitic pathogens. All were negative for viral and typhoid serology. Nine patients had Brucella antibodies present by at least one of the tests, four of whom had evidence suggestive of acute infection by the reference serologic microscopic agglutination test. Three patients were positive for leptospiral antibody by immunoglobulin M enzyme-linked immunosorbent assay, and two were positive for malaria. Although sensitive and specific point-of-care testing methods will improve diagnosis of acute febrile illness in developing countries, challenges of interpretation still remain when the outbreaks are remote, specimens collected too late, and positive results for multiple diseases are obtained. Better diagnostics and tools that can decipher overlapping signs and symptoms in such settings are needed.

Challenges of Establishing the Correct Diagnosis of Outbreaks of Acute Febrile Illnesses in Africa: The Case of a Likely Brucella Outbreak among Nomadic Pastoralists, Northeast Kenya, March–July 2005

PubMed Central

Ari, Mary D.; Guracha, Argata; Fadeel, Moustafa Abdel; Njuguna, Charles; Njenga, M. Kariuki; Kalani, Rosalia; Abdi, Hassan; Warfu, Osman; Omballa, Victor; Tetteh, Christopher; Breiman, Robert F.; Pimentel, Guillermo; Feikin, Daniel R.

2011-01-01

An outbreak of acute febrile illness was reported among Somali pastoralists in remote, arid Northeast Kenya, where drinking raw milk is common. Blood specimens from 12 patients, collected mostly in the late convalescent phase, were tested for viral, bacterial, and parasitic pathogens. All were negative for viral and typhoid serology. Nine patients had Brucella antibodies present by at least one of the tests, four of whom had evidence suggestive of acute infection by the reference serologic microscopic agglutination test. Three patients were positive for leptospiral antibody by immunoglobulin M enzyme-linked immunosorbent assay, and two were positive for malaria. Although sensitive and specific point-of-care testing methods will improve diagnosis of acute febrile illness in developing countries, challenges of interpretation still remain when the outbreaks are remote, specimens collected too late, and positive results for multiple diseases are obtained. Better diagnostics and tools that can decipher overlapping signs and symptoms in such settings are needed. PMID:22049048

Kenya Country Analysis Brief

EIA Publications

2016-01-01

Kenya currently does not produce any hydrocarbons, although the country has the potential to become an oil producer most likely after 2020. Over the past few years, several commercial oil discoveries have been made in Kenya, but the country faces obstacles that have caused production delays. Negotiations over a joint export pipeline route with its neighbor Uganda is in flux, while sustained low oil prices have slowed down exploration drilling activity in Kenya.

The Affordable Medicines Facility-malaria (AMFm): are remote areas benefiting from the intervention?

PubMed

Ye, Yazoume; Arnold, Fred; Noor, Abdisalan; Wamukoya, Marilyn; Amuasi, John; Blay, Samuel; Mberu, Blessing; Ren, Ruilin; Kyobutungi, Catherine; Wekesah, Frederick; Gatakaa, Hellen; Toda, Mitsuru; Njogu, Julius; Evance, Illah; O'Connell, Kathryn; Shewchuk, Tanya; Thougher, Sarah; Mann, Andrea; Willey, Barbara; Goodman, Catherine; Hanson, Kara

2015-10-09

To assess the availability, price and market share of quality-assured artemisinin-based combination therapy (QAACT) in remote areas (RAs) compared with non-remote areas (nRAs) in Kenya and Ghana at end-line of the Affordable Medicines Facility-malaria (AMFm) intervention. Areas were classified by remoteness using a composite index computed from estimated travel times to three levels of service centres. The index was used to five categories of remoteness, which were then grouped into two categories of remote and non-remote areas. The number of public or private outlets with the potential to sell or distribute anti-malarial medicines, screened in nRAs and RAs, respectively, was 501 and 194 in Ghana and 9980 and 2353 in Kenya. The analysis compares RAs with nRAs in terms of availability, price and market share of QAACT in each country. QAACT were similarly available in RAs as nRAs in Ghana and Kenya. In both countries, there was no statistical difference in availability of QAACT with AMFm logo between RAs and nRAs in public health facilities (PHFs), while private-for-profit (PFP) outlets had lower availability in RA than in nRAs (Ghana: 66.0 vs 82.2 %, p < 0.0001; Kenya: 44.9 vs 63.5 %, p = <0.0001. The median price of QAACT with AMFm logo for PFP outlets in RAs (USD1.25 in Ghana and USD0.69 in Kenya) was above the recommended retail price in Ghana (US$0.95) and Kenya (US$0.46), and much higher than in nRAs for both countries. QAACT with AMFm logo represented the majority of QAACT in RAs and nRAs in Kenya and Ghana. In the PFP sector in Ghana, the market share for QAACT with AMFm logo was significantly higher in RAs than in nRAs (75.6 vs 51.4 %, p < 0.0001). In contrast, in similar outlets in Kenya, the market share of QAACT with AMFm logo was significantly lower in RAs than in nRAs (39.4 vs 65.1 %, p < 0.0001). The findings indicate the AMFm programme contributed to making QAACT more available in RAs in these two countries. Therefore, the AMFm approach can inform

A review of measles control in Kenya, with focus on recent innovations.

PubMed

Manakongtreecheep, Kasidet; Davis, Robert

2017-01-01

Despite the existence of a highly effective measles vaccine and the decrease in worldwide deaths from measles by more than 79% from the 2000 baseline levels, measles today remains one of the leading causes of vaccine-preventable deaths in the world. The African region is a key player in the global fight against measles. Africa has made tremendous progress in its effort to immunize children and to control the disease, increasing its regional measles vaccination coverage from 56% in 2001 to 85% in 2010. The Republic of Kenya has been a strong follower of the World Health Assembly and Measles Elimination 2020 resolutions, which aims to eliminate measles from the country. Since the beginning of the 21st century, Kenya has faced many challenges, but also aid, in the form of new innovations, in their fight against measles. In 2002, Kenya started its first SIA using A-D syringes, and from 2003-2005, GAVI funded injection safety support (INS) to Kenya, as an effort to scale-up safe injection in sub-Saharan Africa. In 2016, the Kenya introduced Measles-Rubella (MR) combined vaccine in its nationwide SIA campaign, after recognizing that rubella is a disease that must be controlled along with measles. In 2009 and 2012 SIAs, Red Cross volunteers conducted H2H visits to promote immunization as well as document information from the community with regards to immunization, including the current coverage, to campaign management levels. Case-based surveillance, using real-time PCR, measles-specific IgM detection and Epi-link were used to confirm and map measles infection during outbreaks. Alternative serosurveys such as Dried Blood Spot and Urine sample surveys were also tested in Kenya. In 2013 and 2016, two studies were also conducted in Kenya on the use of SMS reminder system for routine immunization. These studies, which showed SMS to significantly improve the vaccination coverage, paved way for use of SMS in a larger scale in Kenya.

A review of measles control in Kenya, with focus on recent innovations

PubMed Central

Manakongtreecheep, Kasidet; Davis, Robert

2017-01-01

Despite the existence of a highly effective measles vaccine and the decrease in worldwide deaths from measles by more than 79% from the 2000 baseline levels, measles today remains one of the leading causes of vaccine-preventable deaths in the world. The African region is a key player in the global fight against measles. Africa has made tremendous progress in its effort to immunize children and to control the disease, increasing its regional measles vaccination coverage from 56% in 2001 to 85% in 2010. The Republic of Kenya has been a strong follower of the World Health Assembly and Measles Elimination 2020 resolutions, which aims to eliminate measles from the country. Since the beginning of the 21st century, Kenya has faced many challenges, but also aid, in the form of new innovations, in their fight against measles. In 2002, Kenya started its first SIA using A-D syringes, and from 2003-2005, GAVI funded injection safety support (INS) to Kenya, as an effort to scale-up safe injection in sub-Saharan Africa. In 2016, the Kenya introduced Measles-Rubella (MR) combined vaccine in its nationwide SIA campaign, after recognizing that rubella is a disease that must be controlled along with measles. In 2009 and 2012 SIAs, Red Cross volunteers conducted H2H visits to promote immunization as well as document information from the community with regards to immunization, including the current coverage, to campaign management levels. Case-based surveillance, using real-time PCR, measles-specific IgM detection and Epi-link were used to confirm and map measles infection during outbreaks. Alternative serosurveys such as Dried Blood Spot and Urine sample surveys were also tested in Kenya. In 2013 and 2016, two studies were also conducted in Kenya on the use of SMS reminder system for routine immunization. These studies, which showed SMS to significantly improve the vaccination coverage, paved way for use of SMS in a larger scale in Kenya. PMID:29296150

Zoom in at African country level: potential climate induced changes in areas of suitability for survival of malaria vectors.

PubMed

Tonnang, Henri E Z; Tchouassi, David P; Juarez, Henry S; Igweta, Lilian K; Djouaka, Rousseau F

2014-05-07

Predicting anopheles vectors' population densities and boundary shifts is crucial in preparing for malaria risks and unanticipated outbreaks. Although shifts in the distribution and boundaries of the major malaria vectors (Anopheles gambiae s.s. and An. arabiensis) across Africa have been predicted, quantified areas of absolute change in zone of suitability for their survival have not been defined. In this study, we have quantified areas of absolute change conducive for the establishment and survival of these vectors, per African country, under two climate change scenarios and based on our findings, highlight practical measures for effective malaria control in the face of changing climatic patterns. We developed a model using CLIMEX simulation platform to estimate the potential geographical distribution and seasonal abundance of these malaria vectors in relation to climatic factors (temperature, rainfall and relative humidity). The model yielded an eco-climatic index (EI) describing the total favourable geographical locations for the species. The EI values were classified and exported to a GIS package. Using ArcGIS, the EI shape points were clipped to the extent of Africa and then converted to a raster layer using Inverse Distance Weighted (IDW) interpolation method. Generated maps were then transformed into polygon-based geo-referenced data set and their areas computed and expressed in square kilometers (km(2)). Five classes of EI were derived indicating the level of survivorship of these malaria vectors. The proportion of areas increasing or decreasing in level of survival of these malaria vectors will be more pronounced in eastern and southern African countries than those in western Africa. Angola, Ethiopia, Kenya, Mozambique, Tanzania, South Africa and Zambia appear most likely to be affected in terms of absolute change of malaria vectors suitability zones under the selected climate change scenarios. The potential shifts of these malaria vectors have

Spatiotemporal clusters of malaria cases at village level, northwest Ethiopia.

PubMed

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

2014-06-06

Malaria attacks are not evenly distributed in space and time. In highland areas with low endemicity, malaria transmission is highly variable and malaria acquisition risk for individuals is unevenly distributed even within a neighbourhood. Characterizing the spatiotemporal distribution of malaria cases in high-altitude villages is necessary to prioritize the risk areas and facilitate interventions. Spatial scan statistics using the Bernoulli method were employed to identify spatial and temporal clusters of malaria in high-altitude villages. Daily malaria data were collected, using a passive surveillance system, from patients visiting local health facilities. Georeference data were collected at villages using hand-held global positioning system devices and linked to patient data. Bernoulli model using Bayesian approaches and Marcov Chain Monte Carlo (MCMC) methods were used to identify the effects of factors on spatial clusters of malaria cases. The deviance information criterion (DIC) was used to assess the goodness-of-fit of the different models. The smaller the DIC, the better the model fit. Malaria cases were clustered in both space and time in high-altitude villages. Spatial scan statistics identified a total of 56 spatial clusters of malaria in high-altitude villages. Of these, 39 were the most likely clusters (LLR = 15.62, p < 0.00001) and 17 were secondary clusters (LLR = 7.05, p < 0.03). The significant most likely temporal malaria clusters were detected between August and December (LLR = 17.87, p < 0.001). Travel away home, males and age above 15 years had statistically significant effect on malaria clusters at high-altitude villages. The study identified spatial clusters of malaria cases occurring at high elevation villages within the district. A patient who travelled away from home to a malaria-endemic area might be the most probable source of malaria infection in a high-altitude village. Malaria interventions in high altitude villages should

Malaria

MedlinePlus

Malaria is a serious disease caused by a parasite. You get it when an infected mosquito bites you. Malaria is a major cause of death worldwide, but ... at risk. There are four different types of malaria caused by four related parasites. The most deadly ...

Entertainment Education and Social Change: Evaluating a Children's Soap Opera in Kenya

ERIC Educational Resources Information Center

de Block, Liesbeth

2012-01-01

This article discusses audience responses to a children's soap opera produced and broadcast in Kenya. It examines the evaluation process in relation to qualitative audience research within Cultural Studies. It challenges an Entertainment-Education model of media as vehicles for messages and links strongly with Communication for Social Change…

Precipitation Based Malaria Patterns in the Amazon -- Will Deforestation Alter Risk?

NASA Astrophysics Data System (ADS)

Olson, S. H.; Durieux, L.; Elguero, E.; Foley, J.; Gagnon, R.; Guegan, J.; Patz, J.

2007-12-01

The World Health Organization, estimates that forty-two percent of malaria cases are "associated with policies and practices regarding land use, deforestation, water resource management, settlement siting and modified house design". This estimate was drawn from expert opinion and studies performed at local scales, but little research has investigated the cumulative impacts of land use and land cover changes occurring in the Amazon Basin on malaria. Much less is understood about the impact of changing land use and subsequent precipitation regimes on malaria risk. To understand how land use practices may alter malaria patterns in the Basin we present an analysis of municipio (n=755) malaria case data and monthly precipitation patterns between 1996 and 1999. Climate data originated from the CRU TS 2.1 half-degree grid resolution climate data set. We present a hierarchical (random coefficients) log-linear Poisson model relating malaria incidence to precipitation for both municipos and states. At the Basin scale precipitation and cases show strong relationships. Precipitation and cases are asynchronous across the period of observation, but detailed inspection of states and individual municipios reveal geographic dependencies of precipitation and malaria incidence. Future research will link the patterns of precipitation and malaria to anticipated changes in climate from deforestation in the Basin.

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

Uptake of three doses of HPV vaccine by primary school girls in Eldoret, Kenya; a prospective cohort study in a malaria endemic setting.

PubMed

Mabeya, Hillary; Menon, Sonia; Weyers, Steven; Naanyu, Violet; Mwaliko, Emily; Kirop, Elijah; Orango, Omenge; Vermandere, Heleen; Vanden Broeck, Davy

2018-05-11

All women are potentially at risk of developing cervical cancer at some point in their life, yet it is avoidable cause of death among women in Sub- Saharan Africa with a world incidence of 530,000 every year. It is the 4th commonest cancer affecting women worldwide with over 260,000 deaths reported in 2012. Low resource settings account for over 75% of the global cervical cancer burden. Uptake of HPV vaccination is limited in the developing world. WHO recommended that 2 doses of HPV vaccine could be given to young girls, based on studies in developed countries. However in Africa high rates of infections like malaria and worms can affect immune responses to vaccines, therefore three doses may still be necessary. The aim of this study was to identify barriers and facilitators associated with uptake of HPV vaccine. A cross-sectional survey was conducted at Eldoret, Kenya involving 3000 girls aged 9 to 14 years from 40 schools. Parents/guardians gave consent through a questionnaire. Of all 3083 the school girls 93.8% had received childhood vaccines and 63.8% had a second HPV dose, and 39.1% had a third dose. Administration of second dose and HPV knowledge were both strong predictors of completion of the third dose. Distance to the hospital was a statistically significant risk factor for non-completion (P: 0.01). Distance to vaccination centers requires a more innovative vaccine-delivery strategy and education of parents/guardians on cervical screening to increase attainment of the HPV vaccination.

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

Quantifying the economic burden of malaria in Nigeria using the willingness to pay approach

PubMed Central

Jimoh, Ayodele; Sofola, Oluyemi; Petu, Amos; Okorosobo, Tuoyo

2007-01-01

Background Malaria illness imposes great burden on the society as it has adverse effects on the physical, mental and social well being of the people as well as on the economic development of the nation. Methods The study uses the Willingness To Pay (WTP) approach to evaluate the burden of malaria in Nigeria. Results The results indicate that households would be prepared to pay an average of about Naira 1,112 (USD 9.3) per month for the treatment of malaria. This is about Naira 427 (USD 3.6) in excess of the average expenditure they currently make on malaria treatment per month. Similarly, households are willing to pay on the average a sum of Naira 7,324 (USD 61) per month for the control of malaria. Again, this is an excess of about Naira 2,715 (USD 22.6) over the cost they currently bear (protection, treatment and indirect costs), and it represents households' average valuation of their intangible costs of malaria illness. This amount represents about Naira 611.7 (USD 5.1) per head per month and Naira 7,340 (USD 61.2) per year. For a country with a population of about 120 million this translates to about Naira 880,801 million per annum representing about 12.0 per cent of Gross Domestic Product. Hence, the malaria burden in Nigeria is enormous and has a devastating impact on economic growth. Conclusion In the long term, it is important to recognize that health and poverty are closely linked. Reducing the burden of malaria in Nigeria will help to contribute to the economic well-being of communities; and poverty-reduction will be an essential input into improving health. National malaria control programme in Nigeria and their partners need to recognize these links, and identify mechanisms for ensuring that the poorest have access to essential health interventions. PMID:17517146

Intermittent screening and treatment or intermittent preventive treatment with dihydroartemisinin-piperaquine versus intermittent preventive treatment with sulfadoxine-pyrimethamine for the control of malaria during pregnancy in western Kenya: an open-label, three-group, randomised controlled superiority trial.

PubMed

Desai, Meghna; Gutman, Julie; L'lanziva, Anne; Otieno, Kephas; Juma, Elizabeth; Kariuki, Simon; Ouma, Peter; Were, Vincent; Laserson, Kayla; Katana, Abraham; Williamson, John; ter Kuile, Feiko O

2015-12-19

Every year, more than 32 million pregnancies in sub-Saharan Africa are at risk of malaria infection and its adverse consequences. The effectiveness of the intermittent preventive treatment with sulfadoxine-pyrimethamine strategy recommended by WHO is threatened by high levels of parasite resistance. We aimed to assess the efficacy and safety of two alternative strategies: intermittent screening with malaria rapid diagnostic tests and treatment of women who test positive with dihydroartemisinin-piperaquine, and intermittent preventive treatment with dihydroartemisinin-piperaquine. We did this open-label, three-group, randomised controlled superiority trial at four sites in western Kenya with high malaria transmission and sulfadoxine-pyrimethamine resistance. HIV-negative pregnant women between 16 and 32 weeks' gestation were randomly assigned (1:1:1), via computer-generated permuted-block randomisation (block sizes of three, six, and nine), to receive intermittent screening and treatment with dihydroartemisinin-piperaquine, intermittent preventive treatment with dihydroartemisinin-piperaquine, or intermittent preventive treatment with sulfadoxine-pyrimethamine. Study participants, study clinic nurses, and the study coordinator were aware of treatment allocation, but allocation was concealed from study investigators, delivery unit nurses, and laboratory staff. The primary outcome was malaria infection at delivery, defined as a composite of peripheral or placental parasitaemia detected by placental histology, microscopy, or rapid diagnostic test. The primary analysis was by modified intention to treat. This study is registered with ClinicalTrials.gov, number NCT01669941. Between Aug 21, 2012, and June 19, 2014, we randomly assigned 1546 women to receive intermittent screening and treatment with dihydroartemisinin-piperaquine (n=515), intermittent preventive treatment with dihydroartemisinin-piperaquine (n=516), or intermittent preventive treatment with sulfadoxine

Attributing Climate Conditions for Stable Malaria Transmission to Human Activity in sub-Saharan Africa

NASA Astrophysics Data System (ADS)

Sheldrake, L.; Mitchell, D.; Allen, M. R.

2015-12-01

Temperature and precipitation limit areas of stable malaria transmission, but the effects of climate change on the disease remain controversial. Previously, studies have not separated the influence of anthropogenic climate change and natural variability, despite being an essential step in the attribution of climate change impacts. Ensembles of 2900 simulations of regional climate in sub-Saharan Africa for the year 2013, one representing realistic conditions and the other how climate might have been in the absence of human influence, were used to force a P.falciparium climate suitability model developed by the Mapping Malaria Risk in Africa project. Strongest signals were detected in areas of unstable transmission, indicating their heightened sensitivity to climatic factors. Evidently, impacts of human-induced climate change were unevenly distributed: the probability of conditions being suitable for stable malaria transmission were substantially reduced (increased) in the Sahel (Greater Horn of Africa (GHOA), particularly in the Ethiopian and Kenyan highlands). The length of the transmission season was correspondingly shortened in the Sahel and extended in the GHOA, by 1 to 2 months, including in Kericho (Kenya), where the role of climate change in driving recent malaria occurrence is hotly contested. Human-induced warming was primarily responsible for positive anomalies in the GHOA, while reduced rainfall caused negative anomalies in the Sahel. The latter was associated with anthropogenic impacts on the West African Monsoon, but uncertainty in the RCM's ability to reproduce precipitation trends in the region weakens confidence in the result. That said, outputs correspond well with broad-scale changes in observed endemicity, implying a potentially important contribution of anthropogenic climate change to the malaria burden during the past century. Results support the health-framing of climate risk and help indicate hotspots of climate vulnerability, providing

PGMS: a case study of collecting PDA-based geo-tagged malaria-related survey data.

PubMed

Zhou, Ying; Lobo, Neil F; Wolkon, Adam; Gimnig, John E; Malishee, Alpha; Stevenson, Jennifer; Sulistyawati; Collins, Frank H; Madey, Greg

2014-09-01

Using mobile devices, such as personal digital assistants (PDAs), smartphones, tablet computers, etc., to electronically collect malaria-related field data is the way for the field questionnaires in the future. This case study seeks to design a generic survey framework PDA-based geo-tagged malaria-related data collection tool (PGMS) that can be used not only for large-scale community-level geo-tagged electronic malaria-related surveys, but also for a wide variety of electronic data collections of other infectious diseases. The framework includes two parts: the database designed for subsequent cross-sectional data analysis and the customized programs for the six study sites (two in Kenya, three in Indonesia, and one in Tanzania). In addition to the framework development, we also present our methods used when configuring and deploying the PDAs to 1) reduce data entry errors, 2) conserve battery power, 3) field install the programs onto dozens of handheld devices, 4) translate electronic questionnaires into local languages, 5) prevent data loss, and 6) transfer data from PDAs to computers for future analysis and storage. Since 2008, PGMS has successfully accomplished quite a few surveys that recorded 10,871 compounds and households, 52,126 persons, and 17,100 bed nets from the six sites. These numbers are still growing. © The American Society of Tropical Medicine and Hygiene.

Malaria chemoprophylaxis in the age of drug resistance. II. Drugs that may be available in the future.

PubMed

Shanks, G D; Kain, K C; Keystone, J S

2001-08-01

All current regimens of malaria chemoprophylaxis have serious drawbacks as a result of either suboptimal efficacy, difficulty with medication compliance, or adverse events. Two 8-aminoquinolines may be approaching registration, with primaquine having completed its prophylactic field testing and tafenoquine having begun advanced field testing at the end of 2000. Primaquine has long been used for management of relapses of malaria, but in the past decade, it has been reexamined for use in malaria prevention in order to stop infection in the liver. In field trials performed in Indonesia and Colombia, the efficacy of primaquine for malaria prevention was approximately 90%, compared with that of placebo. Because of its short half-life, primaquine requires daily administration. For adults, the prevention regimen is 30 mg base daily (0.5 mg base/kg/day), and it can probably be discontinued soon after departure from an area where malaria is endemic. To kill parasites that already exist in the liver, terminal prophylaxis is given after exposure to relapses of malaria infection; for adults, such prophylaxis usually consists of 15 mg base (0.3 mg base/kg/day) given daily for 2 weeks. Primaquine-induced gastrointestinal disturbances can be minimized if the drug is taken with food. Neither primaquine nor tafenoquine should be given to persons with glucose-6-phosphate dehydrogenase deficiency, to avoid the development of potentially severe drug-induced hemolysis. Tafenoquine is an analogue of primaquine that is more potent than the parent drug. Field trials in Kenya, Ghana, Gabon, and Southeast Asia have demonstrated an efficacy rate of approximately 90% for tafenoquine. Its long half-life allows for infrequent dosing (currently tested at 200 mg base/week), and its effect on parasites at the liver stage may allow for drug discontinuation at the time of departure from the area of endemicity.

Reducing Stock-Outs of Life Saving Malaria Commodities Using Mobile Phone Text-Messaging: SMS for Life Study in Kenya

PubMed Central

Githinji, Sophie; Kigen, Samwel; Memusi, Dorothy; Nyandigisi, Andrew; Mbithi, Agneta M.; Wamari, Andrew; Muturi, Alex N.; Jagoe, George; Barrington, Jim; Snow, Robert W.; Zurovac, Dejan

2013-01-01

Background Health facility stock-outs of life saving malaria medicines are common across Africa. Innovative ways of addressing this problem are urgently required. We evaluated whether SMS based reporting of stocks of artemether-lumefantrine (AL) and rapid diagnostic tests (RDT) can result in reduction of stock-outs at peripheral facilities in Kenya. Methods/Findings All 87 public health facilities in five Kenyan districts were included in a 26 week project. Weekly facility stock counts of four AL packs and RDTs were sent via structured incentivized SMS communication process from health workers’ personal mobile phones to a web-based system accessed by district managers. The mean health facility response rate was 97% with a mean formatting error rate of 3%. Accuracy of stock count reports was 79% while accuracy of stock-out reports was 93%. District managers accessed the system 1,037 times at an average of eight times per week. The system was accessed in 82% of the study weeks. Comparing weeks 1 and 26, stock-out of one or more AL packs declined by 38 percentage-points. Total AL stock-out declined by 5 percentage-points and was eliminated by the end of the project. Stock-out declines of individual AL packs ranged from 14 to 32 percentage-points while decline in RDT stock-outs was 24 percentage-points. District managers responded to 44% of AL and 73% of RDT stock-out signals by redistributing commodities between facilities. In comparison with national trends, stock-out declines in study areas were greater, sharper and more sustained. Conclusions Use of simple SMS technology ensured high reporting rates of reasonably accurate, real-time facility stock data that were used by district managers to undertake corrective actions to reduce stock-outs. Future work on stock monitoring via SMS should focus on assessing response rates without use of incentives and demonstrating effectiveness of such interventions on a larger scale. PMID:23349786

Beer Consumption Increases Human Attractiveness to Malaria Mosquitoes

PubMed Central

Lefèvre, Thierry; Gouagna, Louis-Clément; Dabiré, Kounbobr Roch; Elguero, Eric; Fontenille, Didier; Renaud, François; Costantini, Carlo; Thomas, Frédéric

2010-01-01

Background Malaria and alcohol consumption both represent major public health problems. Alcohol consumption is rising in developing countries and, as efforts to manage malaria are expanded, understanding the links between malaria and alcohol consumption becomes crucial. Our aim was to ascertain the effect of beer consumption on human attractiveness to malaria mosquitoes in semi field conditions in Burkina Faso. Methodology/Principal Findings We used a Y tube-olfactometer designed to take advantage of the whole body odour (breath and skin emanations) as a stimulus to gauge human attractiveness to Anopheles gambiae (the primary African malaria vector) before and after volunteers consumed either beer (n = 25 volunteers and a total of 2500 mosquitoes tested) or water (n = 18 volunteers and a total of 1800 mosquitoes). Water consumption had no effect on human attractiveness to An. gambiae mosquitoes, but beer consumption increased volunteer attractiveness. Body odours of volunteers who consumed beer increased mosquito activation (proportion of mosquitoes engaging in take-off and up-wind flight) and orientation (proportion of mosquitoes flying towards volunteers' odours). The level of exhaled carbon dioxide and body temperature had no effect on human attractiveness to mosquitoes. Despite individual volunteer variation, beer consumption consistently increased attractiveness to mosquitoes. Conclusions/Significance These results suggest that beer consumption is a risk factor for malaria and needs to be integrated into public health policies for the design of control measures. PMID:20209056

Age-Related Buildup of Humoral Immunity against Epitopes for Rosette Formation and Agglutination in African Areas of Malaria Endemicity

PubMed Central

Barragan, Antonio; Kremsner, Peter G.; Weiss, Walter; Wahlgren, Mats; Carlson, Johan

1998-01-01

In this report, we show an age-related buildup of agglutinating activity as well as serum activity against rosette formation in children living in areas of Kenya and Gabon where malaria is endemic. Sera from Kenyans in general exhibited a stronger and wider immune response toward the epitopes, probably reflecting a difference in transmission patterns between the two areas. Thus, our results indicate that repeated malaria attacks in areas of endemicity, and consequently exposure to different isolate-specific antigens, will elicit an antibody-mediated response eventually enabling recognition of the majority of rosetting and agglutinating antigens. The correlation between antirosetting and agglutinating capacity was poor in individual cases, indicating that the rosetting epitopes are only a minor part of the highly diverse surface-exposed antigens (mainly PfEMP1) on the surface of parasitized erythrocytes toward which antibodies may react. These data together with our previous findings that the protection against cerebral malaria correlates with presence of antirosetting antibodies shed new light on our understanding of the gradual acquisition of immunity toward severe complications of malarial infection which children reared in areas of endemicity attain. PMID:9746579

Kenya.

PubMed

1985-07-01

Kenya's 1st census, in 1948, counted 5.8 million people, the 1979 census counted 15.3 million, and the government estimates the 1984 population at 19.4 million. Development planning began in 1966; the current 5-year plan (1984-1988) stresses manpower, capital, and land development, mainly in the West. The government considers population growth an obstacle to meeting educational, health, housing, food, and employment needs. Kenya's high 4% growth rate results from a high birth rate and a declining death rate. The government intends to reduce population growth to 3.3% by 1988 by 1) informing Kenyans of the benefits of small families and 2) making family planning services easily available, especially in rural areas. Life expectancy is currently 52.9 years and infant mortality is 82/1000. Most health problems relate to childbearing, communicable diseases, malnutrition, and poor sanitation. The current development plan strives to expand services in 1) staff training, information, and education, 2) monitoring and evaluation, 3) contraceptive delivery, and 4) increasing family planning acceptors. Kenyan women desire 7 children and usually have 8. The government is trying to improve the status of women through education and employment, with the expectation of reducing fertility levels. Abortion for contraceptive purposes is illegal; sterilization and contraceptives are available. Neither emigration nor immigration are significant in Kenya. 90% of the people live on 20% of the land. Urban growth is increasing too rapidly and the government's policies to correct the population distribution inequity include 1) urban development, mainly in Western Kenya; 2) encouraging agricultural development; 3) development of export-oriented, resource based, and labor intensive industries; 4) funding development sites outside of Nairobi and Mombasa; 5) stimulating growth in undeveloped areas; 6) improving roads, rails, and ports; and 7) providing adequate water, housing, and energy.

Malaria.

ERIC Educational Resources Information Center

Dupasquier, Isabelle

1989-01-01

Malaria, the greatest pandemia in the world, claims an estimated one million lives each year in Africa alone. While it may still be said that for the most part malaria is found in what is known as the world's poverty belt, cases are now frequently diagnosed in western countries. Due to resistant strains of malaria which have developed because of…

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

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

The relevance of non-human primate and rodent malaria models for humans

PubMed Central

2011-01-01

At the 2010 Keystone Symposium on "Malaria: new approaches to understanding Host-Parasite interactions", an extra scientific session to discuss animal models in malaria research was convened at the request of participants. This was prompted by the concern of investigators that skepticism in the malaria community about the use and relevance of animal models, particularly rodent models of severe malaria, has impacted on funding decisions and publication of research using animal models. Several speakers took the opportunity to demonstrate the similarities between findings in rodent models and human severe disease, as well as points of difference. The variety of malaria presentations in the different experimental models parallels the wide diversity of human malaria disease and, therefore, might be viewed as a strength. Many of the key features of human malaria can be replicated in a variety of nonhuman primate models, which are very under-utilized. The importance of animal models in the discovery of new anti-malarial drugs was emphasized. The major conclusions of the session were that experimental and human studies should be more closely linked so that they inform each other, and that there should be wider access to relevant clinical material. PMID:21288352

Implications of insecticide resistance for malaria vector control with long-lasting insecticidal nets: a WHO-coordinated, prospective, international, observational cohort study.

PubMed

Kleinschmidt, Immo; Bradley, John; Knox, Tessa Bellamy; Mnzava, Abraham Peter; Kafy, Hmooda Toto; Mbogo, Charles; Ismail, Bashir Adam; Bigoga, Jude D; Adechoubou, Alioun; Raghavendra, Kamaraju; Cook, Jackie; Malik, Elfatih M; Nkuni, Zinga José; Macdonald, Michael; Bayoh, Nabie; Ochomo, Eric; Fondjo, Etienne; Awono-Ambene, Herman Parfait; Etang, Josiane; Akogbeto, Martin; Bhatt, Rajendra M; Chourasia, Mehul Kumar; Swain, Dipak K; Kinyari, Teresa; Subramaniam, Krishanthi; Massougbodji, Achille; Okê-Sopoh, Mariam; Ogouyemi-Hounto, Aurore; Kouambeng, Celestin; Abdin, Mujahid Sheikhedin; West, Philippa; Elmardi, Khalid; Cornelie, Sylvie; Corbel, Vincent; Valecha, Neena; Mathenge, Evan; Kamau, Luna; Lines, Jonathan; Donnelly, Martin James

2018-04-09

Scale-up of insecticide-based interventions has averted more than 500 million malaria cases since 2000. Increasing insecticide resistance could herald a rebound in disease and mortality. We aimed to investigate whether insecticide resistance was associated with loss of effectiveness of long-lasting insecticidal nets and increased malaria disease burden. This WHO-coordinated, prospective, observational cohort study was done at 279 clusters (villages or groups of villages in which phenotypic resistance was measurable) in Benin, Cameroon, India, Kenya, and Sudan. Pyrethroid long-lasting insecticidal nets were the principal form of malaria vector control in all study areas; in Sudan this approach was supplemented by indoor residual spraying. Cohorts of children from randomly selected households in each cluster were recruited and followed up by community health workers to measure incidence of clinical malaria and prevalence of infection. Mosquitoes were assessed for susceptibility to pyrethroids using the standard WHO bioassay test. Country-specific results were combined using meta-analysis. Between June 2, 2012, and Nov 4, 2016, 40 000 children were enrolled and assessed for clinical incidence during 1·4 million follow-up visits. 80 000 mosquitoes were assessed for insecticide resistance. Long-lasting insecticidal net users had lower infection prevalence (adjusted odds ratio [OR] 0·63, 95% CI 0·51-0·78) and disease incidence (adjusted rate ratio [RR] 0·62, 0·41-0·94) than did non-users across a range of resistance levels. We found no evidence of an association between insecticide resistance and infection prevalence (adjusted OR 0·86, 0·70-1·06) or incidence (adjusted RR 0·89, 0·72-1·10). Users of nets, although significantly better protected than non-users, were nevertheless subject to high malaria infection risk (ranging from an average incidence in net users of 0·023, [95% CI 0·016-0·033] per person-year in India, to 0·80 [0·65-0·97] per person

The economic burden of inpatient paediatric care in Kenya: household and provider costs for treatment of pneumonia, malaria and meningitis

PubMed Central

Ayieko, Philip; Akumu, Angela O; Griffiths, Ulla K; English, Mike

2009-01-01

Background Knowledge of treatment cost is essential in assessing cost effectiveness in healthcare. Evidence of the potential impact of implementing available interventions against childhood illnesses in developing countries challenges us to define the costs of treating these diseases. The purpose of this study is to describe the total costs associated with treatment of pneumonia, malaria and meningitis in children less than five years in seven Kenyan hospitals. Methods Patient resource use data were obtained from largely prospective evaluation of medical records and household expenditure during illness was collected from interviews with caretakers. The estimates for costs per bed day were based on published data. A sensitivity analysis was conducted using WHO-CHOICE values for costs per bed day. Results Treatment costs for 572 children (pneumonia = 205, malaria = 211, meningitis = 102 and mixed diagnoses = 54) and household expenditure for 390 households were analysed. From the provider perspective the mean cost per admission at the national hospital was US $95.58 for malaria, US $177.14 for pneumonia and US $284.64 for meningitis. In the public regional or district hospitals the mean cost per child treated ranged from US $47.19 to US $81.84 for malaria and US $54.06 to US $99.26 for pneumonia. The corresponding treatment costs in the mission hospitals were between US $43.23 to US $88.18 for malaria and US $ 43.36 to US $142.22 for pneumonia. Meningitis was treated for US $ 189.41 at the regional hospital and US $ 201.59 at one mission hospital. The total treatment cost estimates were sensitive to changes in the source of bed day costs. The median treatment related household payments within quintiles defined by total household expenditure differed by type of facility visited. Public hospitals recovered up to 40% of provider costs through user charges while mission facilities recovered 44% to 100% of costs. Conclusion Treatments cost for inpatient malaria, pneumonia

Comparative efficacy of existing surveillance tools for Aedes aegypti in Western Kenya.

PubMed

Yalwala, Sancto; Clark, Jeffrey; Oullo, David; Ngonga, Daniel; Abuom, David; Wanja, Elizabeth; Bast, Joshua

2015-12-01

All traditional surveillance techniques for Aedes aegypti have been developed for the cosmopolitan domestic subspecies Ae. aegypti aegypti, and not the sylvatic subspecies, Ae. aegypti formosus. The predominant form in Western Kenya is Ae. aegypti formosus that is rarely associated with human habitations but is linked to transmission of sylvatic dengue virus strains. We compared five surveillance methods for their effectiveness in sampling Ae. aegypti formosus with the goal of determining a sustainable surveillance strategy in Kenya. The methods included larval and pupal surveys, oviposition trapping, BG-Sentinel trapping, resting boxes, and backpack aspirations. Larval and pupal surveys collected the highest number of Ae. aegypti formosus (51.3%), followed by oviposition traps (45.7%), BG-Sentinel traps (3.0%), and zero collected with either backpack aspiration or resting box collections. No Ae. aegypti formosus larvae or pupae were found indoors. The results indicate that oviposition traps and outdoor larval and pupal surveys were better surveillance methods for Ae. aegypti formosus in Western Kenya. © 2015 The Society for Vector Ecology.

A Literature Review of the Effect of Malaria on Stunting.

PubMed

Jackson, Bianca D; Black, Robert E

2017-11-01

Background: The current version of the Lives Saved Tool (LiST) maternal and child health impact modeling software does not include an effect of malaria on stunting. Objective: This literature review was undertaken to determine whether such a causal link should be included in the LiST model. Methods: The PubMed, Embase, and Scopus databases were searched by using broad search terms. The searches returned a total of 4281 documents. Twelve studies from among the retrieved documents were included in the review according to the inclusion and exclusion criteria. Results: There was mixed evidence for an effect of malaria on stunting among longitudinal observational studies, and none of the randomized controlled trials of malaria interventions found an effect of the interventions on stunting. Conclusions: There is insufficient evidence to include malaria as a determinant of stunting or an effect of malaria interventions on stunting in the LiST model. The paucity and heterogeneity of the available literature were a major limitation. In addition, the studies included in the review consistently fulfilled their ethical responsibility to treat children under observation for malaria, which may have interfered with the natural history of the disease and prevented any observable effect on stunting or linear growth. © 2017 American Society for Nutrition.

Reduced risk for placental malaria in iron deficient women

PubMed Central

2011-01-01

Background Nutritional iron deficiency may limit iron availability to the malaria parasite reducing infection risk, and/or impair host immunity thereby increasing this risk. In pregnant women, there is evidence of an adverse effect with iron supplementation, but the few reported studies are strongly confounded. Methods A case control study in pregnant Malawian women was undertaken in Chikhwawa southern Malawi in order to describe iron status in relation to placental malaria controlling for several confounding factors. Pregnancy characteristics were obtained and a blood sample at delivery. A full blood count was performed and serum ferritin and transferrin receptor quantified by enzyme-linked immunoassay. DNA analysis was used to identify genetic polymorphisms for ABO phenotype, hemoglobin HbS, and glucose -6 phosphate dehydrogenase deficiency. Placental tissue was obtained and malaria histology classified as active, past or no malaria infection. Results 112 cases with placental malaria were identified and 110 women with no evidence of placental infection. Iron deficiency was less frequent in women with placental Plasmodium falciparum infection. In those with acute, chronic or past placental infections the odds ratio for iron deficiency was 0.4, 95% CI 0.2-0.8, p = 0.01; for acute and chronic infections 0.4, 0.2-0.8, p = 0.006; for acute infection 0.3, 0.1-0.7, p = 0.001. The association was greater in multigravidae. Conclusion Women with either acute, or acute and chronic placental malaria were less likely to have iron deficiency than women without placental malaria infection There is a priority to establish if reversing iron deficiency through iron supplementation programs either prior to or during pregnancy enhances malaria risk. PMID:21345193

Longitudinal estimation of Plasmodium falciparum prevalence in relation to malaria prevention measures in six sub-Saharan African countries.

PubMed

Drakeley, Chris; Abdulla, Salim; Agnandji, Selidji Todagbe; Fernandes, José Francisco; Kremsner, Peter; Lell, Bertrand; Mewono, Ludovic; Bache, Bache Emmanuel; Mihayo, Michael Gabriel; Juma, Omar; Tanner, Marcel; Tahita, Marc Christian; Tinto, Halidou; Diallo, Salou; Lompo, Palpouguini; D'Alessandro, Umberto; Ogutu, Bernhards; Otieno, Lucas; Otieno, Solomon; Otieno, Walter; Oyieko, Janet; Asante, Kwaku Poku; Dery, Dominic Bon-Ereme; Adjei, George; Adeniji, Elisha; Atibilla, Dorcas; Owusu-Agyei, Seth; Greenwood, Brian; Gesase, Samwel; Lusingu, John; Mahende, Coline; Mongi, Robert; Segeja, Method; Adjei, Samuel; Agbenyega, Tsiri; Agyekum, Alex; Ansong, Daniel; Bawa, John Tanko; Boateng, Harry Owusu; Dandalo, Léonard; Escamilla, Veronica; Hoffman, Irving; Maenje, Peter; Martinson, Francis; Carter, Terrell; Leboulleux, Didier; Kaslow, David C; Usuf, Effua; Pirçon, Jean-Yves; Bahmanyar, Edith Roset

2017-10-27

Plasmodium falciparum prevalence (PfPR) is a widely used metric for assessing malaria transmission intensity. This study was carried out concurrently with the RTS,S/AS01 candidate malaria vaccine Phase III trial and estimated PfPR over ≤ 4 standardized cross-sectional surveys. This epidemiology study (NCT01190202) was conducted in 8 sites from 6 countries (Burkina Faso, Gabon, Ghana, Kenya, Malawi, and Tanzania), between March 2011 and December 2013. Participants were enrolled in a 2:1:1 ratio according to age category: 6 months-4 years, 5-19 years, and ≥ 20 years, respectively, per year and per centre. All sites carried out surveys 1-3 while survey 4 was conducted only in 3 sites. Surveys were usually performed during the peak malaria parasite transmission season, in one home visit, when medical history and malaria risk factors/prevention measures were collected, and a blood sample taken for rapid diagnostic test, microscopy, and haemoglobin measurement. PfPR was estimated by site and age category. Overall, 6401 (survey 1), 6411 (survey 2), 6400 (survey 3), and 2399 (survey 4) individuals were included in the analyses. In the 6 months-4 years age group, the lowest prevalence (assessed using microscopy) was observed in 2 Tanzanian centres (4.6% for Korogwe and 9.95% for Bagamoyo) and Lambaréné, Gabon (6.0%), while the highest PfPR was recorded for Nanoro, Burkina Faso (52.5%). PfPR significantly decreased over the 3 years in Agogo (Ghana), Kombewa (Kenya), Lilongwe (Malawi), and Bagamoyo (Tanzania), and a trend for increased PfPR was observed over the 4 surveys for Kintampo, Ghana. Over the 4 surveys, for all sites, PfPR was predominantly higher in the 5-19 years group than in the other age categories. Occurrence of fever and anaemia was associated with high P. falciparum parasitaemia. Univariate analyses showed a significant association of anti-malarial treatment in 4 surveys (odds ratios [ORs]: 0.52, 0.52, 0.68, 0.41) and bed net use in 2

Malaria: An Early Indicator of Later Disease and Work Level

PubMed Central

Hong, Sok Chul

2014-01-01

This study investigates the effect of early-life exposure to malaria on disease and work level in old age over the past one and a half centuries. Using longitudinal lifetime records of Union Army veterans, I first estimate that exposure to a malarial environment in early life (c.1840) substantially increased the likelihood of having various chronic diseases and not working in old age (c.1900). Second, from data on US cohorts born between 1891 and 1960, I find that those exposed to a higher level of the anti-malaria campaign, which began in 1921, had lower levels of work disability in old age. Third, I seek the same implications for the modern period by linking WHO's country statistics on DALYs among older populations in 2004 to country-level malaria risk in pre-eradication era. In the paper, I discuss possible mechanisms and propose the significance of malaria eradication and early-life conditions from a long-term perspective. PMID:23584052

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

First record of the Asian malaria vector Anopheles stephensi and its possible role in the resurgence of malaria in Djibouti, Horn of Africa.

PubMed

Faulde, Michael K; Rueda, Leopoldo M; Khaireh, Bouh A

2014-11-01

Anopheles stephensi is an important vector of urban malaria in India and the Persian Gulf area. Its previously known geographical range includes southern Asia and the Arab Peninsula. For the first time, we report A. stephensi from the African continent, based on collections made in Djibouti, on the Horn of Africa, where this species' occurrence was linked to an unusual urban outbreak of Plasmodium falciparum malaria, with 1228 cases reported from February to May 2013, and a second, more severe epidemic that emerged in November 2013 and resulted in 2017 reported malaria cases between January and February 2014. Anopheles stephensi was initially identified using morphological identification keys, followed by sequencing of the Barcode cytochrome c-oxidase I (COI) gene and the rDNA second internal transcribed spacer (ITS2). Positive tests for P. falciparum circumsporozoite antigen in two of six female A. stephensi trapped in homes of malaria patients in March 2013 are evidence that autochthonous urban malaria transmission by A. stephensi has occurred. Concurrent with the second malaria outbreak, P. falciparum-positive A. stephensi females were detected in Djibouti City starting in November 2013. In sub-Saharan Africa, newly present A. stephensi may pose a significant future health threat because of this species' high susceptibility to P. falciparum infection and its tolerance of urban habitats. This may lead to increased malaria outbreaks in African cities. Rapid interruption of the urban malaria transmission cycle, based on integrated vector surveillance and control programs aimed at the complete eradication of A. stephensi from the African continent, is strongly recommended. Copyright © 2014 Elsevier B.V. All rights reserved.

Zoom in at African country level: potential climate induced changes in areas of suitability for survival of malaria vectors

PubMed Central

2014-01-01

Background Predicting anopheles vectors’ population densities and boundary shifts is crucial in preparing for malaria risks and unanticipated outbreaks. Although shifts in the distribution and boundaries of the major malaria vectors (Anopheles gambiae s.s. and An. arabiensis) across Africa have been predicted, quantified areas of absolute change in zone of suitability for their survival have not been defined. In this study, we have quantified areas of absolute change conducive for the establishment and survival of these vectors, per African country, under two climate change scenarios and based on our findings, highlight practical measures for effective malaria control in the face of changing climatic patterns. Methods We developed a model using CLIMEX simulation platform to estimate the potential geographical distribution and seasonal abundance of these malaria vectors in relation to climatic factors (temperature, rainfall and relative humidity). The model yielded an eco-climatic index (EI) describing the total favourable geographical locations for the species. The EI values were classified and exported to a GIS package. Using ArcGIS, the EI shape points were clipped to the extent of Africa and then converted to a raster layer using Inverse Distance Weighted (IDW) interpolation method. Generated maps were then transformed into polygon-based geo-referenced data set and their areas computed and expressed in square kilometers (km2). Results Five classes of EI were derived indicating the level of survivorship of these malaria vectors. The proportion of areas increasing or decreasing in level of survival of these malaria vectors will be more pronounced in eastern and southern African countries than those in western Africa. Angola, Ethiopia, Kenya, Mozambique, Tanzania, South Africa and Zambia appear most likely to be affected in terms of absolute change of malaria vectors suitability zones under the selected climate change scenarios. Conclusion The potential shifts of

Placental malaria and the risk of malaria in infants in a high malaria transmission area in ghana: a prospective cohort study.

PubMed

Asante, Kwaku Poku; Owusu-Agyei, Seth; Cairns, Matthew; Dodoo, Daniel; Boamah, Ellen Abrafi; Gyasi, Richard; Adjei, George; Gyan, Ben; Agyeman-Budu, Akua; Dodoo, Theophilus; Mahama, Emmanuel; Amoako, Nicholas; Dosoo, David Kwame; Koram, Kwadwo; Greenwood, Brian; Chandramohan, Daniel

2013-11-01

Whether the risk of malaria is increased in infants born to mothers who experience malaria during pregnancy is uncertain.  We investigated malaria incidence among an infant cohort born to 355 primigravidae and 1500 multigravidae with or without placental malaria (PM) in a high malaria transmission area of Ghana. PM was assessed using placental histology. The incidence of all episodes of malaria parasitemia or clinical malaria was very similar among 3 groups of infants: those born to multigravidae without PM, multigravidae with PM, and primigravidae with PM. Infants born to primigravidae without PM experienced a lower incidence of malaria parasitemia or clinical malaria than the other 3 groups: adjusted hazard ratio, 0.64 (95% confidence interval [CI], .48-.86, P < .01) and 0.60 (95% CI, .43-.84, P < .01), respectively. The incidence of malaria parasitemia or clinical malaria was about 2 times higher in most poor infants compared to least poor infants. There was no suggestion that exposure to PM directly increased incidence of malaria among infants of multigravidae. In our study area, absence of placental malaria in primigravidae is a marker of low exposure, and this probably explains the lower incidence of malaria-related outcomes among infants of PM-negative primigravidae.

Interpreting Student Views of Learning Experiences in a Contextualized Science Discourse in Kenya

ERIC Educational Resources Information Center

Nashon, Samson Madera; Anderson, David

2013-01-01

Despite the centrality of the informal manufacturing sector ("Jua Kali") to the Kenyan society and its richness in scientific phenomena, there is no strong link between activities in the Jua Kali and school science. And, although there has been an ongoing public discourse in Kenya to industrialize, this hope is unlikely without…

Lake Naivasha, Kenya

NASA Technical Reports Server (NTRS)

2008-01-01

If you live in Europe and buy roses, there is a good chance that they were grown in Kenya specifically, in one of the colossal greenhouses that blot out the once wild shores of Lake Naivasha, 90km north-west of Nairobi. Some 25% of Europe's cut flowers come from Kenya. After a tentative start in the 1980s the industry is now the country's third-largest foreign-currency earner, bringing in $120m a year. But the recent violence in Kenya is having a major impact on the flower growers. A local trade union says 3,000 of the 30,000 workers employed in Naivasha's flower farms have abandoned their jobs. Kenya emerged as a flower power when Israel scaled down its own industry. It has since lost business to neighboring Ethiopia, which offers tax breaks and better security, but Naivasha's perfect intensity of sunlight and days of near-constant length should keep it on top.

The ASTER image was acquired February 2, 2008, covers an area of 25 x 26.6 km, and is located near 0.8 degrees south latitude, 36.4 degrees east longitude.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

Enhanced acquired antibodies to a chimeric Plasmodium falciparum antigen; UB05-09 is associated with protective immunity against malaria.

PubMed

Dinga, J N; Gamua, S D; Titanji, V P K

2017-08-01

It has been shown that covalently linking two antigens could enhance the immunogenicity of the chimeric construct. To prioritize such a chimera for malaria vaccine development, it is necessary to demonstrate that naturally acquired antibodies against the chimera are associated with protection from malaria. Here, we probe the ability of a chimeric construct of UB05 and UB09 antigens (UB05-09) to better differentiate between acquired immune protection and susceptibility to malaria. In a cross-sectional study, recombinant UB05-09 chimera and the constituent antigens were used to probe for specific antibodies in the plasma from children and adults resident in a malaria-endemic zone, using the enzyme-linked immunosorbent assay (ELISA). Anti-UB05-09 antibody levels doubled that of its constituent antigens, UB09 and UB05, and this correlated with protection against malaria. The presence of enhanced UB05-09-specific antibody correlated with the absence of fever and parasitaemia, which are the main symptoms of malaria infection. The chimera is more effective in detecting and distinguishing acquired protective immunity against malaria than any of its constituents taken alone. Online B-cell epitope prediction tools confirmed the presence of B-cell epitopes in the study antigens. UB05-09 chimera is a marker of protective immunity against malaria that needs to be studied further. © 2017 John Wiley & Sons Ltd.

Malaria transmission and vector behaviour in a forested malaria focus in central Vietnam and the implications for vector control.

PubMed

Van Bortel, Wim; Trung, Ho Dinh; Hoi, Le Xuan; Van Ham, Nguyen; Van Chut, Nguyen; Luu, Nguyen Dinh; Roelants, Patricia; Denis, Leen; Speybroeck, Niko; D'Alessandro, Umberto; Coosemans, Marc

2010-12-23

In Vietnam, malaria is becoming progressively restricted to specific foci where human and vector characteristics alter the known malaria epidemiology, urging for alternative or adapted control strategies. Long-lasting insecticidal hammocks (LLIH) were designed and introduced in Ninh Thuan province, south-central Vietnam, to control malaria in the specific context of forest malaria. An entomological study in this specific forested environment was conducted to assess the behavioural patterns of forest and village vectors and to assess the spatio-temporal risk factors of malaria transmission in the province. Five entomological surveys were conducted in three villages in Ma Noi commune and in five villages in Phuoc Binh commune in Ninh Thuan Province, south-central Vietnam. Collections were made inside the village, at the plot near the slash-and-burn fields in the forest and on the way to the forest. All collected mosquito species were subjected to enzyme-linked immunosorbent assay (ELISA) to detect Plasmodium in the head-thoracic portion of individual mosquitoes after morphological identification. Collection data were analysed by use of correspondence and multivariate analyses. The mosquito density in the study area was low with on average 3.7 anopheline bites per man-night and 17.4 culicine bites per man-night. Plasmodium-infected mosquitoes were only found in the forest and on the way to the forest. Malaria transmission in the forested malaria foci was spread over the entire night, from dusk to dawn, but was most intense in the early evening as nine of the 13 Plasmodium positive bites occurred before 21H. The annual entomological inoculation rate of Plasmodium falciparum was 2.2 infective bites per person-year to which Anopheles dirus s.s. and Anopheles minimus s.s. contributed. The Plasmodium vivax annual entomological inoculation rate was 2.5 infective bites per person-year with Anopheles sawadwongporni, Anopheles dirus s.s. and Anopheles pampanai as vectors. The

Malaria transmission and vector behaviour in a forested malaria focus in central Vietnam and the implications for vector control

PubMed Central

2010-01-01

Background In Vietnam, malaria is becoming progressively restricted to specific foci where human and vector characteristics alter the known malaria epidemiology, urging for alternative or adapted control strategies. Long-lasting insecticidal hammocks (LLIH) were designed and introduced in Ninh Thuan province, south-central Vietnam, to control malaria in the specific context of forest malaria. An entomological study in this specific forested environment was conducted to assess the behavioural patterns of forest and village vectors and to assess the spatio-temporal risk factors of malaria transmission in the province. Methods Five entomological surveys were conducted in three villages in Ma Noi commune and in five villages in Phuoc Binh commune in Ninh Thuan Province, south-central Vietnam. Collections were made inside the village, at the plot near the slash-and-burn fields in the forest and on the way to the forest. All collected mosquito species were subjected to enzyme-linked immunosorbent assay (ELISA) to detect Plasmodium in the head-thoracic portion of individual mosquitoes after morphological identification. Collection data were analysed by use of correspondence and multivariate analyses. Results The mosquito density in the study area was low with on average 3.7 anopheline bites per man-night and 17.4 culicine bites per man-night. Plasmodium-infected mosquitoes were only found in the forest and on the way to the forest. Malaria transmission in the forested malaria foci was spread over the entire night, from dusk to dawn, but was most intense in the early evening as nine of the 13 Plasmodium positive bites occurred before 21H. The annual entomological inoculation rate of Plasmodium falciparum was 2.2 infective bites per person-year to which Anopheles dirus s.s. and Anopheles minimus s.s. contributed. The Plasmodium vivax annual entomological inoculation rate was 2.5 infective bites per person-year with Anopheles sawadwongporni, Anopheles dirus s.s. and

Comparison of Malaria Simulations Driven by Meteorological Observations and Reanalysis Products in Senegal

PubMed Central

Diouf, Ibrahima; Rodriguez-Fonseca, Belen; Deme, Abdoulaye; Caminade, Cyril; Morse, Andrew P.; Cisse, Moustapha; Sy, Ibrahima; Dia, Ibrahima; Ermert, Volker; Ndione, Jacques-André; Gaye, Amadou Thierno

2017-01-01

The analysis of the spatial and temporal variability of climate parameters is crucial to study the impact of climate-sensitive vector-borne diseases such as malaria. The use of malaria models is an alternative way of producing potential malaria historical data for Senegal due to the lack of reliable observations for malaria outbreaks over a long time period. Consequently, here we use the Liverpool Malaria Model (LMM), driven by different climatic datasets, in order to study and validate simulated malaria parameters over Senegal. The findings confirm that the risk of malaria transmission is mainly linked to climate variables such as rainfall and temperature as well as specific landscape characteristics. For the whole of Senegal, a lag of two months is generally observed between the peak of rainfall in August and the maximum number of reported malaria cases in October. The malaria transmission season usually takes place from September to November, corresponding to the second peak of temperature occurring in October. Observed malaria data from the Programme National de Lutte contre le Paludisme (PNLP, National Malaria control Programme in Senegal) and outputs from the meteorological data used in this study were compared. The malaria model outputs present some consistencies with observed malaria dynamics over Senegal, and further allow the exploration of simulations performed with reanalysis data sets over a longer time period. The simulated malaria risk significantly decreased during the 1970s and 1980s over Senegal. This result is consistent with the observed decrease of malaria vectors and malaria cases reported by field entomologists and clinicians in the literature. The main differences between model outputs and observations regard amplitude, but can be related not only to reanalysis deficiencies but also to other environmental and socio-economic factors that are not included in this mechanistic malaria model framework. The present study can be considered as a

Comparison of Malaria Simulations Driven by Meteorological Observations and Reanalysis Products in Senegal.

PubMed

Diouf, Ibrahima; Rodriguez-Fonseca, Belen; Deme, Abdoulaye; Caminade, Cyril; Morse, Andrew P; Cisse, Moustapha; Sy, Ibrahima; Dia, Ibrahima; Ermert, Volker; Ndione, Jacques-André; Gaye, Amadou Thierno

2017-09-25

The analysis of the spatial and temporal variability of climate parameters is crucial to study the impact of climate-sensitive vector-borne diseases such as malaria. The use of malaria models is an alternative way of producing potential malaria historical data for Senegal due to the lack of reliable observations for malaria outbreaks over a long time period. Consequently, here we use the Liverpool Malaria Model (LMM), driven by different climatic datasets, in order to study and validate simulated malaria parameters over Senegal. The findings confirm that the risk of malaria transmission is mainly linked to climate variables such as rainfall and temperature as well as specific landscape characteristics. For the whole of Senegal, a lag of two months is generally observed between the peak of rainfall in August and the maximum number of reported malaria cases in October. The malaria transmission season usually takes place from September to November, corresponding to the second peak of temperature occurring in October. Observed malaria data from the Programme National de Lutte contre le Paludisme (PNLP, National Malaria control Programme in Senegal) and outputs from the meteorological data used in this study were compared. The malaria model outputs present some consistencies with observed malaria dynamics over Senegal, and further allow the exploration of simulations performed with reanalysis data sets over a longer time period. The simulated malaria risk significantly decreased during the 1970s and 1980s over Senegal. This result is consistent with the observed decrease of malaria vectors and malaria cases reported by field entomologists and clinicians in the literature. The main differences between model outputs and observations regard amplitude, but can be related not only to reanalysis deficiencies but also to other environmental and socio-economic factors that are not included in this mechanistic malaria model framework. The present study can be considered as a

Malaria and World War II: German malaria experiments 1939-45.

PubMed

Eckart, W U; Vondra, H

2000-06-01

The epidemiological and pharmacological fight against malaria and German malaria research during the Nazi dictatorship were completely under the spell of war. The Oberkommando des Heeres (German supreme command of the army) suffered the bitter experience of unexpected high losses caused by malaria especially at the Greek front (Metaxes line) but also in southern Russia and in the Ukraine. Hastily raised anti-malaria units tried to teach soldiers how to use the synthetic malaria drugs (Plasmochine, Atebrine) properly. Overdoses of these drugs were numerous during the first half of the war whereas in the second half it soon became clear that it would not be possible to support the army due to insufficient quantities of plasmochine and atebrine. During both running fights and troop withdrawals at all southern and southeastern fronts there was hardly any malaria prophylaxis or treatment. After war and captivity many soldiers returned home to endure heavy malaria attacks. In German industrial (Bayer, IG-Farben) and military malaria laboratories of the Heeres-Sanitäts-Akademie (Army Medical Academy) the situation was characterised by a hasty search for proper dosages of anti-malaria drugs, adequate mechanical and chemical prophylaxis (Petroleum, DDT, and other insecticides) as well as an anti-malaria vaccine. Most importantly, large scale research for proper atebrine and plasmochine dosages was conducted in German concentration camps and mental homes. In Dachau Professor Claus Schilling tested synthetic malaria drugs and injected helpless prisoners with high and sometimes lethal doses. Since the 1920s he had been furiously looking for an anti-malaria vaccine in Italian mental homes and from 1939 he continued his experiments in Dachau. Similar experiments were also performed in Buchenwald and in a psychiatric clinic in Thuringia, where Professor Gerhard Rose tested malaria drugs with mentally ill Russian prisoners of war. Schilling was put to death for his criminal

Supporting formal education to improve quality of health care provided by mothers of children with malaria in rural western Kenya.

PubMed

Kakai, Rose; Menya, Diana; Odero, Wilson

2009-08-30

Home management of malaria (HMM) has been shown to be an effective strategy for reducing childhood mortality from malaria. The direct and especially indirect costs of seeking health care from formal facilities may be substantial, providing a major barrier for many households. Further evaluations of HMM and community-based utilization of available options will help to optimize treatment strategies and maximize health benefits. The purpose of this study was to determine the effect of education, occupation, and family income on the choice of health care options for malaria. This was a cross-sectional, community-based study conducted between November 2007 and December 2007, using quantitative data collection methods. Mothers of children aged younger than five years were interviewed using a questionnaire to elicit responses on the mothers' level of education, occupation, income and malaria health care options. A total of 240 mothers of children aged younger than 5 years were interviewed between November and December, 2007. There was a direct relationship between formal education and occupation. The mean monthly family income was highest among those employed (KSh. 14,421) followed by businesswomen (KSh. 3,106) and farmers (KSh. 1,827) respectively (p<0.01). Those employed were more likely to take their ill children to a health facility (p = 0.05) or choose an antimalarial drug for home treatment. Supporting formal education may scale up the income of family health care providers and improve the quality of HMM among children living in rural communities.

Epidemic and Endemic Malaria Transmission Related to Fish Farming Ponds in the Amazon Frontier

PubMed Central

Barcellos, Christovam; Kitron, Uriel; Camara, Daniel Cardoso Portela; Pereira, Glaucio Rocha; Keppeler, Erlei Cassiano; da Silva-Nunes, Mônica

2015-01-01

Fish farming in the Amazon has been stimulated as a solution to increase economic development. However, poorly managed fish ponds have been sometimes associated with the presence of Anopheles spp. and consequently, with malaria transmission. In this study, we analyzed the spatial and temporal dynamics of malaria in the state of Acre (and more closely within a single county) to investigate the potential links between aquaculture and malaria transmission in this region. At the state level, we classified the 22 counties into three malaria endemicity patterns, based on the correlation between notification time series. Furthermore, the study period (2003–2013) was divided into two phases (epidemic and post-epidemic). Higher fish pond construction coincided both spatially and temporally with increased rate of malaria notification. Within one malaria endemic county, we investigated the relationship between the geolocation of malaria cases (2011–2012) and their distance to fish ponds. Entomological surveys carried out in these ponds provided measurements of anopheline abundance that were significantly associated with the abundance of malaria cases within 100 m of the ponds (P < 0.005; r = 0.39). These results taken together suggest that fish farming contributes to the maintenance of high transmission levels of malaria in this region. PMID:26361330

Towards achieving Abuja targets: identifying and addressing barriers to access and use of insecticides treated nets among the poorest populations in Kenya.

PubMed

Chuma, Jane; Okungu, Vincent; Ntwiga, Janet; Molyneux, Catherine

2010-03-16

Ensuring that the poor and vulnerable population benefit from malaria control interventions remains a challenge for malaria endemic countries. Until recently, ownership and use of insecticides treated nets (ITNs) in most countries was low and inequitable, although coverage has increased in countries where free ITN distribution is integrated into mass vaccination campaigns. In Kenya, free ITNs were distributed to children aged below five years in 2006 through two mass campaigns. High and equitable coverage were reported after the campaigns in some districts, although national level coverage remained low, suggesting that understanding barriers to access remains important. This study was conducted to explore barriers to ownership and use of ITNs among the poorest populations before and after the mass campaigns, to identify strategies for improving coverage, and to make recommendations on how increased coverage levels can be sustained. The study was conducted in the poorest areas of four malaria endemic districts in Kenya. Multiple data collection methods were applied including: cross-sectional surveys (n = 708 households), 24 focus group discussions and semi-structured interviews with 70 ITN suppliers. Affordability was reported as a major barrier to access but non-financial barriers were also shown to be important determinants. On the demand side key barriers to access included: mismatch between the types of ITNs supplied through interventions and community preferences; perceptions and beliefs on illness causes; physical location of suppliers and; distrust in free delivery and in the distribution agencies. Key barriers on the supply side included: distance from manufacturers; limited acceptability of ITNs provided through interventions; crowding out of the commercial sector and the price. Infrastructure, information and communication played a central role in promoting or hindering access. Significant resources have been directed towards addressing affordability

Maternal HIV infection and placental malaria reduce transplacental antibody transfer and tetanus antibody levels in newborns in Kenya.

PubMed

Cumberland, Phillippa; Shulman, Caroline E; Maple, P A Chris; Bulmer, Judith N; Dorman, Edgar K; Kawuondo, Ken; Marsh, Kevin; Cutts, Felicity T

2007-08-15

In clinical trials, maternal tetanus toxoid (TT) vaccination is effective in protecting newborns against tetanus infection, but inadequate placental transfer of tetanus antibodies may contribute to lower-than-expected rates of protection in routine practice. We studied the effect of placental malaria and maternal human immunodeficiency virus (HIV) infection on placental transfer of antibodies to tetanus. A total of 704 maternal-cord paired serum samples were tested by ELISA for antibodies to tetanus. The HIV status of all women was determined by an immunoglobulin G antibody-capture particle-adherence test, and placental malaria was determined by placental biopsy. Maternal history of TT vaccination was recorded. Tetanus antibody levels were reduced by 52% (95% confidence interval [CI], 30%-67%) in newborns of HIV-infected women and by 48% (95% CI, 26%-62%) in newborns whose mothers had active-chronic or past placental malaria. Thirty-seven mothers (5.3%) and 55 newborns (7.8%) had tetanus antibody levels <0.1 IU/mL (i.e., were seronegative). Mothers' self-reported history of lack of tetanus immunization was the strongest predictor of seronegativity and of tetanus antibody levels in maternal and cord serum. Malarial and HIV infections may hinder efforts to eliminate maternal and neonatal tetanus, making implementation of the current policy for mass vaccination of women of childbearing age an urgent priority.

Kenya: Current Conditions and the Challenges Ahead

DTIC Science & Technology

2010-10-06

Peoples Party of Kenya Trumpet 1 NLP National Labour Party Bull (Ndume) 1 KADDU Kenya African Democratic Development Union Fruit Basket (Mavuno) 1 Kenya...Meru 6%, other African 15%, Asian, European, and Arab 1% Religions: Protestant 45%, Roman Catholic 33%, indigenous beliefs 10%, Muslim 10

Vaccines against malaria.

PubMed

Ouattara, Amed; Laurens, Matthew B

2015-03-15

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. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Local perceptions of intermittent screening and treatment for malaria in school children on the south coast of Kenya

PubMed Central

2012-01-01

Background The intermittent screening and treatment (IST) of school children for malaria is one possible intervention strategy that could help reduce the burden of malaria among school children. Future implementation of IST will not only depend on its efficacy and cost-effectiveness but also on its acceptability to parents of the children who receive IST, as well as those responsible for its delivery. This study was conducted alongside a cluster-randomized trial to investigate local perceptions of school-based IST among parents and other stakeholders on the Kenyan south coast. Methods Six out of the 51 schools receiving the IST intervention were purposively sampled, based on the prevalence of Plasmodium infection, to participate in the qualitative study. Twenty-two focus group discussions and 17 in-depth interviews were conducted with parents and other key stakeholders involved in the implementation of school health programmes in the district. Data analysis was guided by the framework analysis method. Results High knowledge of the burden of clinical malaria on school children, the perceived benefits of preventing clinical disease through IST and previous positive experiences and interactions with other school health programmes facilitated the acceptability of IST. However, lack of understanding of the consequences of asymptomatic parasitaemia for apparently healthy school children could potentially contribute to non-adherence to treatment, and use of alternative anti-malarial drugs with simpler regimens was generally preferred. The general consensus of stakeholders was that health workers were best placed to undertake the screening and provide treatment, and although teachers’ involvement in the programme is critical, most participants were opposed to teachers taking finger-prick blood samples from children. There was also a strong demand for the distribution of mosquito nets to augment IST. Conclusion School-based malaria control through IST was acceptable to

The introduction of new policies and strategies to reduce inequities and improve child health in Kenya: A country case study on progress in child survival, 2000-2013.

PubMed

Brault, Marie A; Ngure, Kenneth; Haley, Connie A; Kabaka, Stewart; Sergon, Kibet; Desta, Teshome; Mwinga, Kasonde; Vermund, Sten H; Kipp, Aaron M

2017-01-01

As of 2015, only 12 countries in the World Health Organization's AFRO region had met Millennium Development Goal #4 (MDG#4) to reduce under-five mortality by two-thirds by 2015. Given the variability across the African region, a four-country study was undertaken to examine barriers and facilitators of child survival prior to 2015. Kenya was one of the countries selected for an in-depth case study due to its insufficient progress in reducing under-five mortality, with only a 28% reduction between 1990 and 2013. This paper presents indicators, national documents, and qualitative data describing the factors that have both facilitated and hindered Kenya's efforts in reducing child mortality. Key barriers identified in the data were widespread socioeconomic and geographic inequities in access and utilization of maternal, neonatal, and child health (MNCH) care. To reduce these inequities, Kenya implemented three major policies/strategies during the study period: removal of user fees, the Kenya Essential Package for Health, and the Community Health Strategy. This paper uses qualitative data and a policy review to explore the early impacts of these efforts. The removal of user fees has been unevenly implemented as patients still face hidden expenses. The Kenya Essential Package for Health has enabled construction and/or expansion of healthcare facilities in many areas, but facilities struggle to provide Emergency Obstetric and Neonatal Care (EmONC), neonatal care, and many essential medicines and commodities. The Community Health Strategy appears to have had the most impact, improving referrals from the community and provision of immunizations, malaria prevention, and Prevention of Mother-to-Child Transmission of HIV. However, the Community Health Strategy is limited by resources and thus also unevenly implemented in many areas. Although insufficient progress was made pre-2015, with additional resources and further scale-up of new policies and strategies Kenya can make

Plasmodium vivax Hospitalizations in a Monoendemic Malaria Region: Severe Vivax Malaria?

PubMed Central

Quispe, Antonio M.; Pozo, Edwar; Guerrero, Edith; Durand, Salomón; Baldeviano, G. Christian; Edgel, Kimberly A.; Graf, Paul C. F.; Lescano, Andres G.

2014-01-01

Severe malaria caused by Plasmodium vivax is no longer considered rare. To describe its clinical features, we performed a retrospective case control study in the subregion of Luciano Castillo Colonna, Piura, Peru, an area with nearly exclusive vivax malaria transmission. Severe cases and the subset of critically ill cases were compared with a random set of uncomplicated malaria cases (1:4). Between 2008 and 2009, 6,502 malaria cases were reported, including 106 hospitalized cases, 81 of which fit the World Health Organization definition for severe malaria. Of these 81 individuals, 28 individuals were critically ill (0.4%, 95% confidence interval = 0.2–0.6%) with severe anemia (57%), shock (25%), lung injury (21%), acute renal failure (14%), or cerebral malaria (11%). Two potentially malaria-related deaths occurred. Compared with uncomplicated cases, individuals critically ill were older (38 versus 26 years old, P < 0.001), but similar in other regards. Severe vivax malaria monoinfection with critical illness is more common than previously thought. PMID:24752683

Impacts of neglected tropical disease on incidence and progression of HIV/AIDS, tuberculosis, and malaria: scientific links.

PubMed

Simon, G G

2016-01-01

The neglected tropical diseases (NTDs) are the most common infections of humans in Sub-Saharan Africa. Virtually all of the population living below the World Bank poverty figure is affected by one or more NTDs. New evidence indicates a high degree of geographic overlap between the highest-prevalence NTDs (soil-transmitted helminths, schistosomiasis, onchocerciasis, lymphatic filariasis, and trachoma) and malaria and HIV, exhibiting a high degree of co-infection. Recent research suggests that NTDs can affect HIV and AIDS, tuberculosis (TB), and malaria disease progression. A combination of immunological, epidemiological, and clinical factors can contribute to these interactions and add to a worsening prognosis for people affected by HIV/AIDS, TB, and malaria. Together these results point to the impacts of the highest-prevalence NTDs on the health outcomes of malaria, HIV/AIDS, and TB and present new opportunities to design innovative public health interventions and strategies for these 'big three' diseases. This analysis describes the current findings of research and what research is still needed to strengthen the knowledge base of the impacts NTDs have on the big three. Copyright © 2015 The Author. Published by Elsevier Ltd.. All rights reserved.

Larvivorous fish for preventing malaria transmission

PubMed Central

Walshe, Deirdre P; Garner, Paul; Adeel, Ahmed A; Pyke, Graham H; Burkot, Thomas R

2017-01-01

reported on malaria in the community or the density of the adult anopheline population. In the absence of direct evidence of an effect on transmission, we performed a secondary analysis on studies that evaluated the effect of introducing larvivorous fish on the density or presence of immature anopheline mosquitoes (larvae and pupae forms) in water sources to determine whether this intervention has any potential that may justify further research in the control of malaria vectors. Data collection and analysis Two review authors independently screened each article by title and abstract, and examined potentially relevant studies for inclusion using an eligibility form. At least two review authors independently extracted data and assessed risk of bias of included studies. If relevant data were unclear or were not reported, we contacted the study authors for clarification. We presented data in tables, and we summarized studies that evaluated the effects of introducing fish on anopheline immature density or presence, or both. We used the GRADE approach to summarize the certainty of the evidence. We also examined whether the included studies reported any possible adverse impact of introducing larvivorous fish on non-target native species. Main results We identified no studies that reported the effects of introducing larvivorous fish on the primary outcomes of this review: malaria infection in nearby communities, entomological inoculation rate, or on adult Anopheles density. For the secondary analysis, we examined the effects of introducing larvivorous fish on the density and presence of anopheline larvae and pupae in community water sources, and found 15 small studies with a follow-up period between 22 days and five years. These studies were undertaken in Sri Lanka (two studies), India (three studies), Ethiopia (one study), Kenya (two studies), Sudan (one study), Grande Comore Island (one study), Korea (two studies), Indonesia (one study), and Tajikistan (two studies). These

Kenya: Current Conditions and the Challenges Ahead

DTIC Science & Technology

2010-02-04

Kenya Tree 1 PPK Peoples Party of Kenya Trumpet 1 NLP National Labour Party Bull (Ndume) 1 KADDU Kenya African Democratic Development Union Fruit...Luhya 14%, Luo 13%, Kalenjin 12%, Kamba 11%, Kisii 6%, Meru 6%, other African 15%, Asian, European, and Arab 1% Religions: Protestant 45%, Roman

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

Modelling the Contributions of Malaria, HIV, Malnutrition and Rainfall to the Decline in Paediatric Invasive Non-typhoidal Salmonella Disease in Malawi.

PubMed

Feasey, Nicholas A; Everett, Dean; Faragher, E Brian; Roca-Feltrer, Arantxa; Kang'ombe, Arthur; Denis, Brigitte; Kerac, Marko; Molyneux, Elizabeth; Molyneux, Malcolm; Jahn, Andreas; Gordon, Melita A; Heyderman, Robert S

2015-01-01

Nontyphoidal Salmonellae (NTS) are responsible for a huge burden of bloodstream infection in Sub-Saharan African children. Recent reports of a decline in invasive NTS (iNTS) disease from Kenya and The Gambia have emphasised an association with malaria control. Following a similar decline in iNTS disease in Malawi, we have used 9 years of continuous longitudinal data to model the interrelationships between iNTS disease, malaria, HIV and malnutrition. Trends in monthly numbers of childhood iNTS disease presenting at Queen's Hospital, Blantyre, Malawi from 2002 to 2010 were reviewed in the context of longitudinal monthly data describing malaria slide-positivity among paediatric febrile admissions, paediatric HIV prevalence, nutritional rehabilitation unit admissions and monthly rainfall over the same 9 years, using structural equation models (SEM). Analysis of 3,105 iNTS episodes identified from 49,093 blood cultures, showed an 11.8% annual decline in iNTS (p < 0.001). SEM analysis produced a stable model with good fit, revealing direct and statistically significant seasonal effects of malaria and malnutrition on the prevalence of iNTS disease. When these data were smoothed to eliminate seasonal cyclic changes, these associations remained strong and there were additional significant effects of HIV prevalence. These data suggest that the overall decline in iNTS disease observed in Malawi is attributable to multiple public health interventions leading to reductions in malaria, HIV and acute malnutrition. Understanding the impacts of public health programmes on iNTS disease is essential to plan and evaluate interventions.

Coexistence of Malaria and Thalassemia in Malaria Endemic Areas of Thailand

PubMed Central

Kuesap, Jiraporn; Chaijaroenkul, W.; Rungsihirunrat, K.; Pongjantharasatien, K.; Na-Bangchang, Kesara

2015-01-01

Hemoglobinopathy and malaria are commonly found worldwide particularly in malaria endemic areas. Thalassemia, the alteration of globin chain synthesis, has been reported to confer resistance against malaria. The prevalence of thalassemia was investigated in 101 malaria patients with Plasmodium falciparum and Plasmodium vivax along the Thai-Myanmar border to examine protective effect of thalassemia against severe malaria. Hemoglobin typing was performed using low pressure liquid chromatography (LPLC) and α-thalassemia was confirmed by multiplex PCR. Five types of thalassemia were observed in malaria patients. The 2 major types of thalassemia were Hb E (18.8%) and α-thalassemia-2 (11.9%). There was no association between thalassemia hemoglobinopathy and malaria parasitemia, an indicator of malaria disease severity. Thalassemia had no significant association with P. vivax infection, but the parasitemia in patients with coexistence of P. vivax and thalassemia was about 2-3 times lower than those with coexistence of P. falciparum and thalassemia and malaria without thalassemia. Furthermore, the parasitemia of P. vivax in patients with coexistence of Hb E showed lower value than coexistence with other types of thalassemia and malaria without coexistence. Parasitemia, hemoglobin, and hematocrit values in patients with coexistence of thalassemia other than Hb E were significantly lower than those without coexistence of thalassemia. Furthermore, parasitemia with coexistence of Hb E were 2 times lower than those with coexistence of thalassemia other than Hb E. In conclusion, the results may, at least in part, support the protective effect of thalassemia on the development of hyperparasitemia and severe anemia in malaria patients. PMID:26174819

Kenya Hospices and Palliative Care Association: integrating palliative care in public hospitals in Kenya.

PubMed

Ali, Zipporah

2016-01-01

In Kenya, cancers as a disease group rank third as a cause of death after infectious and cardiovascular diseases. It is estimated that the annual incidence of cancer is about 37,000 new cases with an annual mortality of 28,000 cases (Kenya National Cancer Control Strategy 2010). The incidence of non-communicable diseases accounts for more than 50% of total hospital admissions and over 55% of hospital deaths (Kenya National Strategy for the Prevention and Control of Non Communicable Diseases 2015-2020). The prevalence of HIV is 6.8 (KIAS 2014). Most of these patients will benefit from palliative care services, hence the need to integrate palliative care services in the public healthcare system. The process of integrating palliative care in public hospitals involved advocacy both at the national level and at the institutional level, training of healthcare professionals, and setting up services within the hospitals that we worked with. Technical support was provided to each individual institution as needed. Eleven provincial hospitals across the country have now integrated palliative care services (Palliative Care Units) and are now centres of excellence. Over 220 healthcare providers have been trained, and approximately, over 30,000 patients have benefited from these services. Oral morphine is now available in the hospital palliative care units. As a success of the pilot project, Kenya Hospices and Palliative Care Association (KEHPCA) is now working with the Ministry of Health Kenya to integrate palliative care services in 30 other county hospitals across the country, thus ensuring more availability and access to more patients. Other developing countries can learn from Kenya's successful experience.

Plasmodium vivax hospitalizations in a monoendemic malaria region: severe vivax malaria?

PubMed

Quispe, Antonio M; Pozo, Edwar; Guerrero, Edith; Durand, Salomón; Baldeviano, G Christian; Edgel, Kimberly A; Graf, Paul C F; Lescano, Andres G

2014-07-01

Severe malaria caused by Plasmodium vivax is no longer considered rare. To describe its clinical features, we performed a retrospective case control study in the subregion of Luciano Castillo Colonna, Piura, Peru, an area with nearly exclusive vivax malaria transmission. Severe cases and the subset of critically ill cases were compared with a random set of uncomplicated malaria cases (1:4). Between 2008 and 2009, 6,502 malaria cases were reported, including 106 hospitalized cases, 81 of which fit the World Health Organization definition for severe malaria. Of these 81 individuals, 28 individuals were critically ill (0.4%, 95% confidence interval = 0.2-0.6%) with severe anemia (57%), shock (25%), lung injury (21%), acute renal failure (14%), or cerebral malaria (11%). Two potentially malaria-related deaths occurred. Compared with uncomplicated cases, individuals critically ill were older (38 versus 26 years old, P < 0.001), but similar in other regards. Severe vivax malaria monoinfection with critical illness is more common than previously thought. © The American Society of Tropical Medicine and Hygiene.

Modelling climate change and malaria transmission.

PubMed

Parham, Paul E; Michael, Edwin

2010-01-01

The impact of climate change on human health has received increasing attention in recent years, with potential impacts due to vector-borne diseases only now beginning to be understood. As the most severe vector-borne disease, with one million deaths globally in 2006, malaria is thought most likely to be affected by changes in climate variables due to the sensitivity of its transmission dynamics to environmental conditions. While considerable research has been carried out using statistical models to better assess the relationship between changes in environmental variables and malaria incidence, less progress has been made on developing process-based climate-driven mathematical models with greater explanatory power. Here, we develop a simple model of malaria transmission linked to climate which permits useful insights into the sensitivity of disease transmission to changes in rainfall and temperature variables. Both the impact of changes in the mean values of these key external variables and importantly temporal variation in these values are explored. We show that the development and analysis of such dynamic climate-driven transmission models will be crucial to understanding the rate at which P. falciparum and P. vivax may either infect, expand into or go extinct in populations as local environmental conditions change. Malaria becomes endemic in a population when the basic reproduction number R0 is greater than unity and we identify an optimum climate-driven transmission window for the disease, thus providing a useful indicator for determing how transmission risk may change as climate changes. Overall, our results indicate that considerable work is required to better understand ways in which global malaria incidence and distribution may alter with climate change. In particular, we show that the roles of seasonality, stochasticity and variability in environmental variables, as well as ultimately anthropogenic effects, require further study. The work presented here

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.

Demonstration of successful malaria forecasts for Botswana using an operational seasonal climate model

NASA Astrophysics Data System (ADS)

MacLeod, Dave A.; Jones, Anne; Di Giuseppe, Francesca; Caminade, Cyril; Morse, Andrew P.

2015-04-01

The severity and timing of seasonal malaria epidemics is strongly linked with temperature and rainfall. Advance warning of meteorological conditions from seasonal climate models can therefore potentially anticipate unusually strong epidemic events, building resilience and adapting to possible changes in the frequency of such events. Here we present validation of a process-based, dynamic malaria model driven by hindcasts from a state-of-the-art seasonal climate model from the European Centre for Medium-Range Weather Forecasts. We validate the climate and malaria models against observed meteorological and incidence data for Botswana over the period 1982-2006 the longest record of observed incidence data which has been used to validate a modeling system of this kind. We consider the impact of climate model biases, the relationship between climate and epidemiological predictability and the potential for skillful malaria forecasts. Forecast skill is demonstrated for upper tercile malaria incidence for the Botswana malaria season (January-May), using forecasts issued at the start of November; the forecast system anticipates six out of the seven upper tercile malaria seasons in the observational period. The length of the validation time series gives confidence in the conclusion that it is possible to make reliable forecasts of seasonal malaria risk, forming a key part of a health early warning system for Botswana and contributing to efforts to adapt to climate change.

Evaluating the Causal Link Between Malaria Infection and Endemic Burkitt Lymphoma in Northern Uganda: A Mendelian Randomization Study.

PubMed

Legason, Ismail D; Pfeiffer, Ruth M; Udquim, Krizia-Ivana; Bergen, Andrew W; Gouveia, Mateus H; Kirimunda, Samuel; Otim, Isaac; Karlins, Eric; Kerchan, Patrick; Nabalende, Hadijah; Bayanjargal, Ariunaa; Emmanuel, Benjamin; Kagwa, Paul; Talisuna, Ambrose O; Bhatia, Kishor; Yeager, Meredith; Biggar, Robert J; Ayers, Leona W; Reynolds, Steven J; Goedert, James J; Ogwang, Martin D; Fraumeni, Joseph F; Prokunina-Olsson, Ludmila; Mbulaiteye, Sam M

2017-11-01

Plasmodium falciparum (Pf) malaria infection is suspected to cause endemic Burkitt Lymphoma (eBL), but the evidence remains unsettled. An inverse relationship between sickle cell trait (SCT) and eBL, which supports that between malaria and eBL, has been reported before, but in small studies with low power. We investigated this hypothesis in children in a population-based study in northern Uganda using Mendelian Randomization. Malaria-related polymorphisms (SCT, IL10, IL1A, CD36, SEMA3C, and IFNAR1) were genotyped in 202 eBL cases and 624 controls enrolled during 2010-2015. We modeled associations between genotypes and eBL or malaria using logistic regression. SCT was associated with decreased risk of eBL (adjusted odds ratio [OR] 0·37, 95% CI 0·21-0·66; p=0·0003). Decreased risk of eBL was associated with IL10 rs1800896-CT (OR 0·73, 95% CI 0·50-1·07) and -CC genotypes (OR 0·53, 95% CI 0·29-0·95, p trend =0·019); IL1A rs2856838-AG (OR 0·56, 95% CI 0·39-0·81) and -AA genotype (OR 0·50, 95% CI 0·28-1·01, p trend =0·0016); and SEMA3C rs4461841-CT or -CC genotypes (OR 0·57, 95% CI 0·35-0·93, p=0·0193). SCT and IL10 rs1800896, IL1A rs2856838, but not SEMA3C rs4461841, polymorphisms were associated with decreased risk of malaria in the controls. Our results support a causal effect of malaria infection on eBL. Published by Elsevier B.V.

Early age at time of primary Epstein-Barr virus infection results in poorly controlled viral infection in infants from Western Kenya: clues to the etiology of endemic Burkitt lymphoma.

PubMed

Piriou, Erwan; Asito, Amolo S; Sumba, Peter O; Fiore, Nancy; Middeldorp, Jaap M; Moormann, Ann M; Ploutz-Snyder, Robert; Rochford, Rosemary

2012-03-15

Infection with Epstein-Barr virus (EBV) early in life and repeated malaria exposure have been proposed as risk factors for endemic Burkitt lymphoma (eBL). Infants were enrolled from 2 rural sites in Kenya: the Kisumu District, where malaria transmission is holoendemic and risk for eBL is high, and the Nandi District, where malaria transmission is limited and the risk for eBL is low. Blood samples were taken from infants through 2 years of age to measure EBV viral load, EBV antibodies, and malaria parasitemia. We observed a significantly younger age at time of primary EBV infection in children from Kisumu compared with children from Nandi (mean age, 7.28 months [±0.33 SEM] in Kisumu vs 8.39 months [±0.26 SEM] in Nandi), with 35.3% of children in Kisumu infected before 6 months of age. To analyze how different predictors affected EBV viral load over time, we performed multilevel mixed modeling. This modeling revealed that residence in Kisumu and younger age at first EBV infection were significant predictors for having a higher EBV viral load throughout the period of observation. Children from a region at high risk for eBL were infected very early in life with EBV, resulting in higher viral loads throughout infancy.

Seasonal vaccination against malaria: a potential use for an imperfect malaria vaccine.

PubMed

Greenwood, Brian; Dicko, Alassane; Sagara, Issaka; Zongo, Issaka; Tinto, Halidou; Cairns, Matthew; Kuepfer, Irene; Milligan, Paul; Ouedraogo, Jean-Bosco; Doumbo, Ogobara; Chandramohan, Daniel

2017-05-02

In many parts of the African Sahel and sub-Sahel, where malaria remains a major cause of mortality and morbidity, transmission of the infection is highly seasonal. Seasonal malaria chemoprevention (SMC), which involves administration of a full course of malaria treatment to young children at monthly intervals during the high transmission season, is proving to be an effective malaria control measure in these areas. However, SMC does not provide complete protection and it is demanding to deliver for both families and healthcare givers. Furthermore, there is a risk of the emergence in the future of resistance to the drugs, sulfadoxine-pyrimethamine and amodiaquine, that are currently being used for SMC. Substantial progress has been made in the development of malaria vaccines during the past decade and one malaria vaccine, RTS,S/AS01, has received a positive opinion from the European Medicines Authority and will soon be deployed in large-scale, pilot implementation projects in sub-Saharan Africa. A characteristic feature of this vaccine, and potentially of some of the other malaria vaccines under development, is that they provide a high level of efficacy during the period immediately after vaccination, but that this wanes rapidly, perhaps because it is difficult to develop effective immunological memory to malaria antigens in subjects exposed previously to malaria infection. A potentially effective way of using malaria vaccines with high initial efficacy but which provide only a short period of protection could be annual, mass vaccination campaigns shortly before each malaria transmission season in areas where malaria transmission is confined largely to a few months of the year.

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.

Combining malaria control with house electrification: adherence to recommended behaviours for proper deployment of solar-powered mosquito trapping systems, Rusinga Island, western Kenya.

PubMed

Oria, Prisca A; Alaii, Jane; Ayugi, Margaret; Takken, Willem; Leeuwis, Cees

2015-08-01

To investigate community adherence to recommended behaviours for proper deployment of solar-powered mosquito trapping systems (SMoTS) after 3- to 10-week use. Solar-powered mosquito trapping system, which also provided power for room lighting and charging mobile phones, were installed in houses in Rusinga Island, western Kenya. We used a structured checklist for observations and a semi-structured questionnaire for interviews in 24 homesteads. We also analysed the subject of 224 community calls to the project team for technical maintenance of SMoTS. Most respondents cared for SMoTS by fencing, emptying and cleaning the trap. Our observations revealed that most traps were fenced, clean and in good working condition. A significantly higher proportion of community calls was lighting-related. Lighting was the main reason respondents liked SMoTS because it reduced or eliminated expenditure on kerosene. However, some respondents observed they no longer heard sounds of mosquitoes inside their houses. All respondents reportedly slept under insecticide-treated nets (ITNs) before receiving SMoTS. After receiving SMoTS, most respondents reportedly continued to use ITNs citing that the project advised them to do so. Some beach residents stopped using ITNs because they no longer heard mosquitoes or due to heat discomfort caused by lights. Electricity-related incentives played a greater role in encouraging adherence to recommended behaviours for proper deployment of SMoTS than the potential health benefits in the early stages of the intervention. Although energy-related financial incentives may play a role, they are insufficient to ensure adherence to health advice, even in the short term. Ongoing community engagement and research monitors and addresses adherence to recommended behaviours including continuation of current malaria control strategies. © 2015 John Wiley & Sons Ltd.

A westward extension of the tropical Pacific warm pool leads to March through June drying in Kenya and Ethiopia

USGS Publications Warehouse

Williams, A. Park; Funk, Christopher C.

2010-01-01

An estimated 14.3 million people are currently (July 2010) food insecure in Kenya and Ethiopia, and the U.S. government has spent more than $972 million on food aid in these two countries since 2009 (USAID, 2010). This insecurity stems from recent drought and rapid population growth that has outpaced agricultural development (Funk and others, 2008; Funk and Brown, 2009). Previous work by Funk and others (2005, 2008) and Verdin and others (2005) has linked drought conditions in Kenya and Ethiopia with warm sea surface temperatures (SSTs) in the Indian Ocean. Recent work has shown that Indian Ocean SSTs substantially affect rainfall in this region from March through June (Funk and others, 2008; Funk and Verdin, 2009). This season is known as the 'long rains' in Kenya and the 'Belg' rains in Ethiopia.

Kenya.

PubMed

Obura, D O

2001-12-01

The Kenya coast is bathed by the northward-flowing warm waters of the East Africa Coastal Current, located between latitudes 1 and 5 degrees S. With a narrow continental shelf, the coastal marine environments are dominated by coral reefs, seagrass beds and mangroves, with large expanses of sandy substrates where river inputs from Kenya's two largest rivers, the Tana and Athi rivers, prevent the growth of coral reefs. The northern part of the coast is seasonally influenced by upwelling waters of the Somali Current, resulting in lower water temperatures for part of the year. The coast is made up of raised Pleistocene reefs on coastal plains and hills of sedimentary origin, which support native habitats dominated by scrub bush and remnant pockets of the forests that used to cover East Africa and the Congo basin. The marine environment is characterized by warm tropical conditions varying at the surface between 25 degrees C and 31 degrees C during the year, stable salinity regimes, and moderately high nutrient levels from terrestrial runoff and groundwater. The semi-diurnal tidal regime varies from 1.5 to 4 m amplitude from neap to spring tides, creating extensive intertidal platform and rocky-shore communities exposed twice-daily during low tides. Fringing reef crests dominate the whole southern coast and parts of the northern coast towards Somalia, forming a natural barrier to the wave energy from the ocean. Coral reefs form the dominant ecosystem along the majority of the Kenya coast, creating habitats for seagrasses and mangroves in the lagoons and creeks protected by the reef crests. Kenya's marine environment faces a number of threats from the growing coastal human population estimated at just under three million in 2000. Extraction of fish and other resources from the narrow continental shelf, coral reef and mangrove ecosystems increases each year with inadequate monitoring and management structures to protect the resource bases. Coastal development in urban and

Using pay for performance incentives (P4P) to improve management of suspected malaria fevers in rural Kenya: a cluster randomized controlled trial.

PubMed

Menya, Diana; Platt, Alyssa; Manji, Imran; Sang, Edna; Wafula, Rebeccah; Ren, Jing; Cheruiyot, Olympia; Armstrong, Janice; Neelon, Brian; O'Meara, Wendy Prudhomme

2015-10-16

Inappropriate treatment of non-malaria fevers with artemisinin-based combination therapies (ACTs) is a growing concern, particularly in light of emerging artemisinin resistance, but it is a behavior that has proven difficult to change. Pay for performance (P4P) programs have generated interest as a mechanism to improve health service delivery and accountability in resource-constrained health systems. However, there has been little experimental evidence to establish the effectiveness of P4P in developing countries. We tested a P4P strategy that emphasized parasitological diagnosis and appropriate treatment of suspected malaria, in particular reduction of unnecessary consumption of ACTs. A random sample of 18 health centers was selected and received a refresher workshop on malaria case management. Pre-intervention baseline data was collected from August to September 2012. Facilities were subsequently randomized to either the comparison (n = 9) or intervention arm (n = 9). Between October 2012 and November 2013, facilities in the intervention arm received quarterly incentive payments based on seven performance indicators. Incentives were for use by facilities rather than as payments to individual providers. All non-pregnant patients older than 1 year of age who presented to a participating facility and received either a malaria test or artemether-lumefantrine (AL) were eligible to be included in the analysis. Our primary outcome was prescription of AL to patients with a negative malaria diagnostic test (n = 11,953). Our secondary outcomes were prescription of AL to patients with laboratory-confirmed malaria (n = 2,993) and prescription of AL to patients without a malaria diagnostic test (analyzed at the cluster level, n = 178 facility-months). In the final quarter of the intervention period, the proportion of malaria-negative patients in the intervention arm who received AL was lower than in the comparison arm (7.3% versus 10.9%). The improvement

Congenital Malaria in China

PubMed Central

Liu, Xue; Culleton, Richard; Tao, Li; Xia, Hui; Gao, Qi

2014-01-01

Abstract Background Congenital malaria, in which infants are directly infected with malaria parasites from their mother prior to or during birth, is a potentially life-threatening condition that occurs at relatively low rates in malaria-endemic regions. It is recognized as a serious problem in Plasmodium falciparum–endemic sub-Saharan Africa, where recent data suggests that it is more common than previously believed. In such regions where malaria transmission is high, neonates may be protected from disease caused by congenital malaria through the transfer of maternal antibodies against the parasite. However, in low P. vivax–endemic regions, immunity to vivax malaria is low; thus, there is the likelihood that congenital vivax malaria poses a more significant threat to newborn health. Malaria had previously been a major parasitic disease in China, and congenital malaria case reports in Chinese offer valuable information for understanding the risks posed by congenital malaria to neonatal health. As most of the literature documenting congenital malaria cases in China are written in Chinese and therefore are not easily accessible to the global malaria research community, we have undertaken an extensive review of the Chinese literature on this subject. Methods/Principal Findings Here, we reviewed congenital malaria cases from three major searchable Chinese journal databases, concentrating on data from 1915 through 2011. Following extensive screening, a total of 104 cases of congenital malaria were identified. These cases were distributed mainly in the eastern, central, and southern regions of China, as well as in the low-lying region of southwest China. The dominant species was P. vivax (92.50%), reflecting the malaria parasite species distribution in China. The leading clinical presentation was fever, and other clinical presentations were anaemia, jaundice, paleness, diarrhoea, vomiting, and general weakness. With the exception of two cases, all patients were cured

Linking field-based ecological data with remotely sensed data using a geographic information system in two malaria endemic urban areas of Kenya.

PubMed

Eisele, Thomas P; Keating, Joseph; Swalm, Chris; Mbogo, Charles M; Githeko, Andrew K; Regens, James L; Githure, John I; Andrews, Linda; Beier, John C

2003-12-10

BACKGROUND: Remote sensing technology provides detailed spectral and thermal images of the earth's surface from which surrogate ecological indicators of complex processes can be measured. METHODS: Remote sensing data were overlaid onto georeferenced entomological and human ecological data randomly sampled during April and May 2001 in the cities of Kisumu (population asymptotically equal to 320,000) and Malindi (population asymptotically equal to 81,000), Kenya. Grid cells of 270 meters x 270 meters were used to generate spatial sampling units for each city for the collection of entomological and human ecological field-based data. Multispectral Thermal Imager (MTI) satellite data in the visible spectrum at five meter resolution were acquired for Kisumu and Malindi during February and March 2001, respectively. The MTI data were fit and aggregated to the 270 meter x 270 meter grid cells used in field-based sampling using a geographic information system. The normalized difference vegetation index (NDVI) was calculated and scaled from MTI data for selected grid cells. Regression analysis was used to assess associations between NDVI values and entomological and human ecological variables at the grid cell level. RESULTS: Multivariate linear regression showed that as household density increased, mean grid cell NDVI decreased (global F-test = 9.81, df 3,72, P-value = <0.01; adjusted R2 = 0.26). Given household density, the number of potential anopheline larval habitats per grid cell also increased with increasing values of mean grid cell NDVI (global F-test = 14.29, df 3,36, P-value = <0.01; adjusted R2 = 0.51). CONCLUSIONS: NDVI values obtained from MTI data were successfully overlaid onto georeferenced entomological and human ecological data spatially sampled at a scale of 270 meters x 270 meters. Results demonstrate that NDVI at such a scale was sufficient to describe variations in entomological and human ecological parameters across both cities.

Medicinal Plants Used by Traditional Healers in Sangurur, Elgeyo Marakwet County, Kenya

PubMed Central

Kigen, Gabriel; Kipkore, Wilson; Wanjohi, Bernard; Haruki, Boniface; Kemboi, Jemutai

2017-01-01

Background: Although herbal medical products are still widely used in Kenya, many of the medicinal plants used by traditional medical practitioners (TMPs) have not been documented, despite several challenges that are now threatening the sustainability of the practice. Objective: To document the medicinal plants and healing methods used by TMPs in a region of Kenya with several recognized herbalists for potential research. Materials and Methods: Semi-structured interviews, group discussions, and direct observations were used to collect ethnopharmacological information. The participant's bio-data, clinical conditions treated, methods of treatment, medicinal plants used, methods of preparation and administration, and dosage forms were recorded. Results: A total of 99 medicinal plants and 12 complementary preparations employed in the treatment of 64 medical conditions were identified. The most widely used plant was Rotala tenella which was used to treat nine medicinal conditions; seven each for Aloe tweediae and Dovyalis abyssinica; and six each for Basella alba and Euclea divinorum. The plants belonged to 55 families with Fabaceae family being the most frequently used (10), followed by Apocynaceae and Solanaceae, each with six species, respectively. We identified plants used to determine the sex of an unborn baby and those used to treat several conditions including anthrax and cerebral malaria and herbs used to detoxify meat from an animal that has died from anthrax. Of special interest was R. tenella which is used to prevent muscle injury. Conclusions: We have documented several plants with potential therapeutic effects. Further research may be conducted to determine their efficacy. SUMMARY The medicinal plants used by traditional healers in a community which still practices herbal medicine in Kenya were documented. A total of 99 medicinal plants and 12 complementary preparations employed in the treatment of 64 medical conditions were identified. Further research may

Medicinal Plants Used by Traditional Healers in Sangurur, Elgeyo Marakwet County, Kenya.

PubMed

Kigen, Gabriel; Kipkore, Wilson; Wanjohi, Bernard; Haruki, Boniface; Kemboi, Jemutai

2017-01-01

Although herbal medical products are still widely used in Kenya, many of the medicinal plants used by traditional medical practitioners (TMPs) have not been documented, despite several challenges that are now threatening the sustainability of the practice. To document the medicinal plants and healing methods used by TMPs in a region of Kenya with several recognized herbalists for potential research. Semi-structured interviews, group discussions, and direct observations were used to collect ethnopharmacological information. The participant's bio-data, clinical conditions treated, methods of treatment, medicinal plants used, methods of preparation and administration, and dosage forms were recorded. A total of 99 medicinal plants and 12 complementary preparations employed in the treatment of 64 medical conditions were identified. The most widely used plant was Rotala tenella which was used to treat nine medicinal conditions; seven each for Aloe tweediae and Dovyalis abyssinica ; and six each for Basella alba and Euclea divinorum . The plants belonged to 55 families with Fabaceae family being the most frequently used (10), followed by Apocynaceae and Solanaceae, each with six species, respectively. We identified plants used to determine the sex of an unborn baby and those used to treat several conditions including anthrax and cerebral malaria and herbs used to detoxify meat from an animal that has died from anthrax. Of special interest was R. tenella which is used to prevent muscle injury. We have documented several plants with potential therapeutic effects. Further research may be conducted to determine their efficacy. The medicinal plants used by traditional healers in a community which still practices herbal medicine in Kenya were documented. A total of 99 medicinal plants and 12 complementary preparations employed in the treatment of 64 medical conditions were identified. Further research may be carried out in order to determine their therapeutic efficacies

Geohelminth Infections among Pregnant Women in Rural Western Kenya; a Cross-Sectional Study

PubMed Central

van Eijk, Anna M.; Lindblade, Kim A.; Odhiambo, Frank; Peterson, Elizabeth; Rosen, Daniel H.; Karanja, Diana; Ayisi, John G.; Shi, Ya Ping; Adazu, Kubaje; Slutsker, Laurence

2009-01-01

Background Geohelminth infections are common in rural western Kenya, but risk factors and effects among pregnant women are not clear. Methodology During a community-based cross-sectional survey, pregnant women were interviewed and asked to provide a blood sample and a single fecal sample. Hemoglobin was measured and a blood slide examined for malaria. Geohelminth infections were identified using the concentration and Kato-Katz method. Results Among 390 participants who provided a stool sample, 76.2% were infected with at least one geohelminth: 52.3% with Ascaris lumbricoides, 39.5% with hookworm, and 29.0% with Trichuris trichiura. Infection with at least one geohelminth species was associated with the use of an unprotected water source (adjusted odds ratio [AOR] 1.8, 95% confidence interval [CI] 1.1–3.0) and the lack of treatment of drinking water (AOR 1.8, 95% CI 1.1–3.1). Geohelminth infections were not associated with clinical symptoms, or low body mass index. A hookworm infection was associated with a lower mid upper arm circumference (adjusted mean decrease 0.7 cm, 95% CI 0.3–1.2 cm). Hookworm infections with an egg count ≥1000/gram feces (11 women) were associated with lower hemoglobin (adjusted mean decrease 1.5 g/dl, 95% CI 0.3–2.7). Among gravidae 2 and 3, women with A. lumbricoides were less likely to have malaria parasitemia (OR 0.4, 95% CI 0.2–0.8) compared to women without A. lumbricoides, unlike other gravidity groups. Conclusion Geohelminth infections are common in this pregnant population; however, there were few observed detrimental effects. Routine provision of antihelminth treatment during an antenatal clinic visit is recommended, but in this area an evaluation of the impact on pregnancy, malaria, and birth outcome is useful. PMID:19172184

Assessment of climate-driven variations in malaria incidence in Swaziland: toward malaria elimination.

PubMed

Chuang, Ting-Wu; Soble, Adam; Ntshalintshali, Nyasatu; Mkhonta, Nomcebo; Seyama, Eric; Mthethwa, Steven; Pindolia, Deepa; Kunene, Simon

2017-06-01

Swaziland aims to eliminate malaria by 2020. However, imported cases from neighbouring endemic countries continue to sustain local parasite reservoirs and initiate transmission. As certain weather and climatic conditions may trigger or intensify malaria outbreaks, identification of areas prone to these conditions may aid decision-makers in deploying targeted malaria interventions more effectively. Malaria case-surveillance data for Swaziland were provided by Swaziland's National Malaria Control Programme. Climate data were derived from local weather stations and remote sensing images. Climate parameters and malaria cases between 2001 and 2015 were then analysed using seasonal autoregressive integrated moving average models and distributed lag non-linear models (DLNM). The incidence of malaria in Swaziland increased between 2005 and 2010, especially in the Lubombo and Hhohho regions. A time-series analysis indicated that warmer temperatures and higher precipitation in the Lubombo and Hhohho administrative regions are conducive to malaria transmission. DLNM showed that the risk of malaria increased in Lubombo when the maximum temperature was above 30 °C or monthly precipitation was above 5 in. In Hhohho, the minimum temperature remaining above 15 °C or precipitation being greater than 10 in. might be associated with malaria transmission. This study provides a preliminary assessment of the impact of short-term climate variations on malaria transmission in Swaziland. The geographic separation of imported and locally acquired malaria, as well as population behaviour, highlight the varying modes of transmission, part of which may be relevant to climate conditions. Thus, the impact of changing climate conditions should be noted as Swaziland moves toward malaria elimination.

Modulation of sickle cell crisis by naturally occurring band 3 specific antibodies -- a malaria link.

PubMed

Kennedy, James Randall

2002-05-01

This paper's focus is prevention of sickle cell adhesion resulting from the erythrocyte's prematurely denatured hemoglobin. This denatured hemoglobin causes a molecule called band 3 to cluster on the erythrocyte's surface and adhere to the CD36 molecule located on the microvascular endothelium. Natural antibodies recognize these clusters on senescent erythrocytes and prevent their endothelial adhesion and target them for reticuloendothelial elimination. Band 3 is also displayed on the erythrocytes of individuals with falciparum malaria and the vaso-occlusive pathology in these patients is prevented in individuals with sickle trait. The hypothesis is that prematurely denatured sickle hemoglobin results in an up regulation of natural antibodies which control erythrocyte adhesion in both malaria and sickle cell disease.

Neonatal and congenital malaria: a case series in malaria endemic eastern Uganda.

PubMed

Olupot-Olupot, Peter; Eregu, Emma I E; Naizuli, Ketty; Ikiror, Julie; Acom, Linda; Burgoine, Kathy

2018-04-20

Congenital malaria is the direct infection of an infant with malaria parasites from their mother prior to or during birth. Neonatal malaria is due to an infective mosquito bite after birth. Neonatal and congenital malaria (NCM) are potentially life-threatening conditions that are believed to occur at relatively low rates in malaria endemic regions. However, recent reports suggest that the number of NCM cases is increasing, and its epidemiology remains poorly described. NCM can mimic other neonatal conditions and because it is thought to be rare, blood film examinations for malaria are not always routinely performed. Consequently, many cases of NCM are likely to be undiagnosed. A retrospective chart review for all neonates admitted with suspected sepsis between January and July 2017 was conducted and noted four cases of NCM since routine malaria testing was introduced as part of standard of care for suspected sepsis at Mbale Regional Referral Hospital Neonatology Unit. This description highlights the need to conduct routine malaria diagnostic testing for febrile neonates in malaria endemic areas, and supports the urgent need to undertake pharmacological studies on therapeutic agents in this population. Four cases (two congenital malaria cases and two neonatal malaria cases) are described after presenting for care at the Mbale Regional Referral Hospital Neonatal Unit (Mbale RRH-NNU). The maternal age was similar across the cases, but both neonatal malaria cases were born to primigravidae. At presentation three cases had fever and history of fever, but one was hypothermic (34.8 °C) and no history of fever. One case of congenital malaria had low birth weight, while the other was born to an HIV positive mother. Both cases of congenital malaria presented with poor feeding, in addition one of them had clinical jaundice. The neonatal malaria cases presented in the third week compared to the congenital malaria cases that presented within 48 h after birth. All of the

Malaria in Children.

PubMed

Cohee, Lauren M; Laufer, Miriam K

2017-08-01

Malaria is a leading cause of morbidity and mortality in endemic areas, leading to an estimated 438,000 deaths in 2015. Malaria is also an important health threat to travelers to endemic countries and should be considered in evaluation of any traveler returning from a malaria-endemic area who develops fever. Considering the diagnosis of malaria in patients with potential exposure is critical. Prompt provision of effective treatment limits the complications of malaria and can be life-saving. Understanding Plasmodium species variation, epidemiology, and drug-resistance patterns in the geographic area where infection was acquired is important for determining treatment choices. Copyright © 2017 Elsevier Inc. All rights reserved.

Exploring the relationship between malaria, rainfall intermittency, and spatial variation in rainfall seasonality

NASA Astrophysics Data System (ADS)

Merkord, C. L.; Wimberly, M. C.; Henebry, G. M.; Senay, G. B.

2014-12-01

Malaria is a major public health problem throughout tropical regions of the world. Successful prevention and treatment of malaria requires an understanding of the environmental factors that affect the life cycle of both the malaria pathogens, protozoan parasites, and its vectors, anopheline mosquitos. Because the egg, larval, and pupal stages of mosquito development occur in aquatic habitats, information about the spatial and temporal distribution of rainfall is critical for modeling malaria risk. Potential sources of hydrological data include satellite-derived rainfall estimates (TRMM and GPM), evapotranspiration derived from a simplified surface energy balance, and estimates of soil moisture and fractional water cover from passive microwave imagery. Previous studies have found links between malaria cases and total monthly or weekly rainfall in areas where both are highly seasonal. However it is far from clear that monthly or weekly summaries are the best metrics to use to explain malaria outbreaks. It is possible that particular temporal or spatial patterns of rainfall result in better mosquito habitat and thus higher malaria risk. We used malaria case data from the Amhara region of Ethiopia and satellite-derived rainfall estimates to explore the relationship between malaria outbreaks and rainfall with the goal of identifying the most useful rainfall metrics for modeling malaria occurrence. First, we explored spatial variation in the seasonal patterns of both rainfall and malaria cases in Amhara. Second, we assessed the relative importance of different metrics of rainfall intermittency, including alternation of wet and dry spells, the strength of intensity fluctuations, and spatial variability in these measures, in determining the length and severity of malaria outbreaks. We also explored the sensitivity of our results to the choice of method for describing rainfall intermittency and the spatial and temporal scale at which metrics were calculated. Results

Fairness and legitimacy of decisions during delivery of malaria services and ITN interventions in Zambia.

PubMed

Tuba, Mary; Sandoy, Ingvild F; Bloch, Paul; Byskov, Jens

2010-11-01

Malaria is the leading cause of morbidity and the second leading cause of mortality in Zambia. Perceptions of fairness and legitimacy of decisions relating to treatment of malaria cases within public health facilities and distribution of ITNs were assessed in a district in Zambia. The study was conducted within the framework of REsponse to ACcountable priority setting for Trust in health systems (REACT), a north-south collaborative action research study, which evaluates the Accountability for Reasonableness (AFR) approach to priority setting in Zambia, Tanzania and Kenya. This paper is based on baseline in-depth interviews (IDIs) conducted with 38 decision-makers, who were involved in prioritization of malaria services and ITN distribution at district, facility and community levels in Zambia, one Focus Group Discussion (FGD) with District Health Management Team managers and eight FGDs with outpatients' attendees. Perceptions and attitudes of providers and users and practices of providers were systematized according to the four AFR conditions relevance, publicity, appeals and leadership. Conflicting criteria for judging fairness were used by decision-makers and patients. Decision-makers argued that there was fairness in delivery of malaria treatment and distribution of ITNs based on alleged excessive supply of free malaria medicines, subsidized ITNs, and presence of a qualified health-provider in every facility. Patients argued that there was unfairness due to differences in waiting time, distances to health facilities, erratic supply of ITNs, no responsive appeal mechanisms, inadequate access to malaria medicines, ITNs and health providers, and uncaring providers. Decision-makers only perceived government bodies and donors/NGOs to be legitimate stakeholders to involve during delivery. Patients found government bodies, patients, indigenous healers, chiefs and politicians to be legitimate stakeholders during both planning and delivery. Poor status of the AFR

Fairness and legitimacy of decisions during delivery of malaria services and ITN interventions in zambia

PubMed Central

2010-01-01

Background Malaria is the leading cause of morbidity and the second leading cause of mortality in Zambia. Perceptions of fairness and legitimacy of decisions relating to treatment of malaria cases within public health facilities and distribution of ITNs were assessed in a district in Zambia. The study was conducted within the framework of REsponse to ACcountable priority setting for Trust in health systems (REACT), a north-south collaborative action research study, which evaluates the Accountability for Reasonableness (AFR) approach to priority setting in Zambia, Tanzania and Kenya. Methods This paper is based on baseline in-depth interviews (IDIs) conducted with 38 decision-makers, who were involved in prioritization of malaria services and ITN distribution at district, facility and community levels in Zambia, one Focus Group Discussion (FGD) with District Health Management Team managers and eight FGDs with outpatients' attendees. Perceptions and attitudes of providers and users and practices of providers were systematized according to the four AFR conditions relevance, publicity, appeals and leadership. Results Conflicting criteria for judging fairness were used by decision-makers and patients. Decision-makers argued that there was fairness in delivery of malaria treatment and distribution of ITNs based on alleged excessive supply of free malaria medicines, subsidized ITNs, and presence of a qualified health-provider in every facility. Patients argued that there was unfairness due to differences in waiting time, distances to health facilities, erratic supply of ITNs, no responsive appeal mechanisms, inadequate access to malaria medicines, ITNs and health providers, and uncaring providers. Decision-makers only perceived government bodies and donors/NGOs to be legitimate stakeholders to involve during delivery. Patients found government bodies, patients, indigenous healers, chiefs and politicians to be legitimate stakeholders during both planning and delivery

Performance of "VIKIA Malaria Ag Pf/Pan" (IMACCESS®), a new malaria rapid diagnostic test for detection of symptomatic malaria infections.

PubMed

Chou, Monidarin; Kim, Saorin; Khim, Nimol; Chy, Sophy; Sum, Sarorn; Dourng, Dany; Canier, Lydie; Nguon, Chea; Ménard, Didier

2012-08-24

Recently, IMACCESS® developed a new malaria test (VIKIA Malaria Ag Pf/Pan™), based on the detection of falciparum malaria (HRP-2) and non-falciparum malaria (aldolase). The performance of this new malaria rapid diagnostic test (RDT) was assessed using 1,000 febrile patients seeking malaria treatment in four health centres in Cambodia from August to December 2011. The results of the VIKIA Malaria Ag Pf/Pan were compared with those obtained by microscopy, the CareStart Malaria™ RDT (AccessBio®) which is currently used in Cambodia, and real-time PCR (as "gold standard"). The best performances of the VIKIA Malaria Ag Pf/Pan™ test for detection of both Plasmodium falciparum and non-P. falciparum were with 20-30 min reading times (sensitivity of 93.4% for P. falciparum and 82.8% for non-P. falciparum and specificity of 98.6% for P. falciparum and 98.9% for non-P. falciparum) and were similar to those for the CareStart Malaria™ test. This new RDT performs similarly well as other commercially available tests (especially the CareStart Malaria™ test, used as comparator), and conforms to the World Health Organization's recommendations for RDT performance. It is a good alternative tool for the diagnosis of malaria in endemic areas.

Factors associated with cholera in Kenya, 2008-2013

PubMed Central

Cowman, Gretchen; Otipo, Shikanga; Njeru, Ian; Achia, Thomas; Thirumurthy, Harsha; Bartram, Jamie; Kioko, Jackson

2017-01-01

Introduction Kenya experienced widespread cholera outbreaks in 1997-1999 and 2007-2010. The re-emergence of cholera in Kenya in 2015 indicates that cholera remains a public health threat. Understanding past outbreaks is important for preventing future outbreaks. This study investigated the relationship between cholera occurrence in Kenya and various environmental and demographic factors related to water, sanitation, socio-economic status, education, urbanization and availability of health facilities during the time period 2008-2013. Methods The primary outcome analyzed was the number of cholera cases at the district level, obtained from the Kenya Ministry of Health's national cholera surveillance records. Values of independent variables were obtained from the 2009 Kenya Population and Housing Census and other national surveys. The data were analyzed using a zero-inflated negative binomial regression model. Results Multivariate analysis indicated that the risk of cholera was associated with open defecation, use of unimproved water sources, poverty headcount ratio and the number of health facilities per 100,000 population (p < 0.05). No statistically significant association was found between cholera occurrence and education, percentage of population living in urban areas or population density. Conclusion The Sustainable Development Goals and Kenya's blueprint for development, Kenya Vision 2030, call for access to sanitation facilities and clean water for all by 2030. Kenya has made important economic strides in recent years but continues to be affected by diseases like cholera that are associated with low socio-economic status. Further expansion of access to sanitation facilities and clean water is necessary for preventing cholera in Kenya. PMID:29515719

Factors associated with cholera in Kenya, 2008-2013.

PubMed

Cowman, Gretchen; Otipo, Shikanga; Njeru, Ian; Achia, Thomas; Thirumurthy, Harsha; Bartram, Jamie; Kioko, Jackson

2017-01-01

Kenya experienced widespread cholera outbreaks in 1997-1999 and 2007-2010. The re-emergence of cholera in Kenya in 2015 indicates that cholera remains a public health threat. Understanding past outbreaks is important for preventing future outbreaks. This study investigated the relationship between cholera occurrence in Kenya and various environmental and demographic factors related to water, sanitation, socio-economic status, education, urbanization and availability of health facilities during the time period 2008-2013. The primary outcome analyzed was the number of cholera cases at the district level, obtained from the Kenya Ministry of Health's national cholera surveillance records. Values of independent variables were obtained from the 2009 Kenya Population and Housing Census and other national surveys. The data were analyzed using a zero-inflated negative binomial regression model. Multivariate analysis indicated that the risk of cholera was associated with open defecation, use of unimproved water sources, poverty headcount ratio and the number of health facilities per 100,000 population (p < 0.05). No statistically significant association was found between cholera occurrence and education, percentage of population living in urban areas or population density. The Sustainable Development Goals and Kenya's blueprint for development, Kenya Vision 2030 , call for access to sanitation facilities and clean water for all by 2030. Kenya has made important economic strides in recent years but continues to be affected by diseases like cholera that are associated with low socio-economic status. Further expansion of access to sanitation facilities and clean water is necessary for preventing cholera in Kenya.

Low uptake of preventive interventions among malaria cases in Swaziland: towards malaria elimination

PubMed Central

Dlamini, N.; Zulu, Z.; Dlamini, S.; Kunene, S.; Sikhondze, W.; Owiti, P.; Geoffroy, E.; Zachariah, R.; Mengestu, T. K.

2018-01-01

Settings: Swaziland is striving to achieve sustainable malaria elimination. Three preventive interventions are vital for reaching this goal: 1) effective household utilisation of long-lasting insecticide nets (LLINs), 2) indoor residual spraying (IRS), and 3) provision of chemoprophylaxis for those travelling to malaria-endemic areas. Objectives: To assess the uptake of preventive intervention among confirmed malaria cases. Design: A longitudinal study using nation-wide programme data from 2010 to 2015. Data on malaria cases from health facilities were sourced from the Malaria Surveillance Database System. Results: Of a total 2568 confirmed malaria cases in Swaziland, 2034 (79%) had complete data on case investigations and were included in the analysis. Of 341 (17%) individuals who owned LLINs, 169 (8%) used them; 338 (17%) had IRS and 314 (15%) slept in sprayed structures. Of 1403 travellers to areas at high malaria risk, 59 (4%) used any form of malaria prevention, including chemoprophylaxis. Conclusion: The uptake of all three key malaria prevention interventions is low, and could threaten the progress made thus far toward malaria elimination. Efforts to improve this situation, including qualitative research to understand the reasons for low uptake, are urgently needed. PMID:29713591

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.

The evil circle of poverty: a qualitative study of malaria and disability

PubMed Central

2012-01-01

Background This article discusses the link between disability and malaria in a poor rural setting. Global malaria programmes and rehabilitation programmes are organized as vertical and separate programmes, and as such they focus on prevention, cure and control, and disability respectively. When looking at specific conditions and illnesses, the impairing long-term consequences of illness incidents during childhood are not questioned. Methods The study design was ethnographic with an open, exploratory approach. Data were collected in Mangochi District in Malawi through qualitative in-depth interviews and participant observation. Results Despite a local-based health service system, people living in poor rural areas are confronted with a multitude of barriers when accessing malaria prevention and treatment. Lack of skilled health personnel and equipment add to the general burden of poverty: insufficient knowledge about health care, problems connected to accessing the health facility in time, insufficient initiatives to prevent malaria attacks, and a general lack of attention to the long term disabling effects of a malaria attack. Conclusions This study points to the importance of building malaria programmes, research and statistics that take into consideration the consequences of permanent impairment after a malaria attack, as well as the context of poverty in which they often occur. In order to do so, one needs to develop methods for detecting people whose disabilities are a direct result of not having received health services after a malaria episode. This may be done through qualitative approaches in local communities and should also be supplemented by suitable surveys in order to estimate the problem on a larger scale. PMID:22236358

Persistent Parasitism: The Adaptive Biology of Malariae and Ovale Malaria.

PubMed

Sutherland, Colin J

2016-10-01

Plasmodium malariae causes malaria in humans throughout the tropics and subtropics. Plasmodium ovale curtisi and Plasmodium ovale wallikeri are sympatric sibling species common in sub-Saharan Africa and also found in Oceania and Asia. Although rarely identified as the cause of malaria cases in endemic countries, PCR detection has confirmed all three parasite species to be more prevalent, and persistent, than previously thought. Chronic, low-density, multispecies asymptomatic infection is a successful biological adaptation by these Plasmodium spp., a pattern also observed among malaria parasites of wild primates. Current whole-genome analyses are illuminating the species barrier separating the ovale parasite species and reveal substantial expansion of subtelomeric gene families. The evidence for and against a quiescent pre-erythrocytic form of P. malariae is reviewed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Re-Emerging Malaria Vectors in Rural Sahel (nouna, Burkina Faso): the Paluclim Project

NASA Astrophysics Data System (ADS)

Vignolles, Cécile; Sauerborn, Rainer; Dambach, Peter; Viel, Christian; Soubeyroux, Jean-Michel; Sié, Ali; Rogier, Christophe; Tourre, Yves M.

2016-06-01

The Paluclim project applied the tele-epidemiology approach, linking climate, environment and public health (CNES, 2008), to rural malaria in Nouna (Burkina Faso). It was to analyze the climate impact on vectorial risks, and its consequences on entomological risks forecast. The objectives were to: 1) produce entomological risks maps in the Nouna region, 2) produce dynamic maps on larvae sites and their productivity, 3) study the climate impact on malaria risks, and 4) evaluate the feasibility of strategic larviciding approach.

Are Long-Lasting Insecticidal Nets Effective for Preventing Childhood Deaths among Non-Net Users? A Community-Based Cohort Study in Western Kenya

PubMed Central

Komazawa, Osuke; Kaneko, Satoshi; K’Opiyo, James; Kiche, Ibrahim; Wanyua, Sheru; Shimada, Masaaki; Karama, Mohamed

2012-01-01

Background Increasing the distribution and use of insecticide-treated nets (ITNs) in Sub-Saharan Africa has made controlling malaria with ITNs more practical. We evaluated community effects induced by ITNs, specifically long-lasting insecticidal nets (LLINs), under ordinary conditions in an endemic malaria area of Western Kenya. Methods Using the database from Mbita Health and Demographic Surveillance System (HDSS), children younger than 5 years old were assessed over four survey periods. We analyzed the effect of bed net usage, LLIN density and population density of young people around a child on all-cause child mortality (ACCM) rates using Cox PH models. Results During the study, 14,554 children were followed and 250 deaths were recorded. The adjusted hazard ratios (HRs) for LLIN usage compared with no net usage were not significant among the models: 1.08 (95%CI 0.76–1.52), 1.19 (95%CI 0.69–2.08) and 0.92 (95%CI 0.42–2.02) for LLIN users, untreated net users, and any net users, respectively. A significant increasing linear trend in risk across LLIN density quartiles (HR = 1.25; 95%CI 1.03–1.51) and a decreasing linear trend in risk across young population density quartiles among non-net user children (HR = 0.77; 95%CI 0.63–0.94) were observed. Conclusions Although our data showed that current LLIN coverage level (about 35%) could induce a community effect to protect children sleeping without bed nets even in a malaria-endemic area, it appears that a better system is needed to monitor the current malaria situation globally in order to optimize malaria control programs with limited resources. PMID:23185378

Strong Association Between Human and Animal Brucella Seropositivity in a Linked Study in Kenya, 2012-2013.

PubMed

Osoro, Eric Mogaka; Munyua, Peninah; Omulo, Sylvia; Ogola, Eric; Ade, Fredrick; Mbatha, Peter; Mbabu, Murithi; Ng'ang'a, Zipporah; Kairu, Salome; Maritim, Marybeth; Thumbi, Samuel M; Bitek, Austine; Gaichugi, Stella; Rubin, Carol; Njenga, Kariuki; Guerra, Marta

2015-08-01

Brucellosis is a common bacterial zoonotic infection but data on the prevalence among humans and animals is limited in Kenya. A cross-sectional survey was conducted in three counties practicing different livestock production systems to simultaneously assess the seroprevalence of, and risk factors for brucellosis among humans and their livestock (cattle, sheep, camels, and goats). A two-stage cluster sampling method with random selection of sublocations and households was conducted. Blood samples were collected from humans and animals and tested for Brucella immunoglobulin G (IgG) antibodies. Human and animal individual seroprevalence was 16% and 8%, respectively. Household and herd seroprevalence ranged from 5% to 73% and 6% to 68%, respectively. There was a 6-fold odds of human seropositivity in households with a seropositive animal compared with those without. Risk factors for human seropositivity included regular ingestion of raw milk (adjusted odds ratio [aOR] = 3.5, 95% confidence interval [CI] = 2.8-4.4), exposure to goats (herding, milking, and feeding) (aOR = 3.1, 95% CI = 2.5-3.8), and handling of animal hides (aOR = 1.8, 95% CI = 1.5-2.2). Attaining at least high school education and above was a protective factor for human seropositivity (aOR = 0.3, 95% CI = 0.3-0.4). This linked study provides evidence of a strong association between human and animal seropositivity at the household level. © The American Society of Tropical Medicine and Hygiene.

Malaria ecotypes and stratification.

PubMed

Schapira, Allan; Boutsika, Konstantina

2012-01-01

To deal with the variability of malaria, control programmes need to stratify their malaria problem into a number of smaller units. Such stratification may be based on the epidemiology of malaria or on its determinants such as ecology. An ecotype classification was developed by the World Health Organization (WHO) around 1990, and it is time to assess its usefulness for current malaria control as well as for malaria modelling on the basis of published research. Journal and grey literature was searched for articles on malaria or Anopheles combined with ecology or stratification. It was found that all malaria in the world today could be assigned to one or more of the following ecotypes: savanna, plains and valleys; forest and forest fringe; foothill; mountain fringe and northern and southern fringes; desert fringe; coastal and urban. However, some areas are in transitional or mixed zones; furthermore, the implications of any ecotype depend on the biogeographical region, sometimes subregion, and finally, the knowledge on physiography needs to be supplemented by local information on natural, anthropic and health system processes including malaria control. Ecotyping can therefore not be seen as a shortcut to determine control interventions, but rather as a framework to supplement available epidemiological and entomological data so as to assess malaria situations at the local level, think through the particular risks and opportunities and reinforce intersectoral action. With these caveats, it does however emerge that several ecotypic distinctions are well defined and have relatively constant implications for control within certain biogeographic regions. Forest environments in the Indo-malay and the Neotropics are, with a few exceptions, associated with much higher malaria risk than in adjacent areas; the vectors are difficult to control, and the anthropic factors also often converge to impose constraints. Urban malaria in Africa is associated with lower risk than savanna

Survey report: Kenya.

PubMed

Van Der Tak, J

1986-06-01

In Kenya, women still average about 8 children each, but the average family size desired by ever-married women dropped by 1 child, from 7.2 to 6.2, between 1978-84. The percentage of currently married women using contraception more than doubled, from 7 to 17%. These are highlights of trends revealed by comparison of the recently released results of the Kenya Contraceptive Prevalence Survey of 1984 with the Kenya Fertility Survey of 1977-78. The latest trends in Kenya's fertility and family planning can be expected to be of worldwide interest in view of the country's record high population growth rate of 4.2% a year. Estimated at 21 million in 1986, the population of Kenya is projected by the UN to quadruple to 83 million by 2025 and could reach as high as 116 million by 2100, according to the World Bank. Among the reasons cited for the failure of Kenya's government family planning program, established in 1968, are bureaucratic snarls, shortages of supplies and trained personnel, and short business hours and long waits in clinics that are not always easily accessible in rural areas. These problems are now being dealt with, but there remains the obstacle of a persistent desire for large families among the population. Over 80% of the 6581 women aged 15-49 interviewed in the 1984 survey knew of at least 1 contraceptive method. The survey report terms the more than doubling of current contraceptive use between 1978-84 as a major success for the family planning program. Yet, the 1984 level is low. Also, the contraceptive mix shifted toward less effective methods. Among currently married women using contraception, the proportion using modern methods was down from 61% in 1978 to 52% in 1984, with oral contraceptive (OC) use dropping from 29 to 19% of the total and rhythm increasing from 16 to 25%. Fertility change was negligible. There was a slight increase in children ever born among women 45-49 from 7.9-8.2 per woman, along with a small decrease in the current total

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.

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

Development and Assessment of Plant-Based Synthetic Odor Baits for Surveillance and Control of Malaria Vectors

PubMed Central

Nyasembe, Vincent O.; Tchouassi, David P.; Kirwa, Hillary K.; Foster, Woodbridge A.; Teal, Peter E. A.; Borgemeister, Christian; Torto, Baldwyn

2014-01-01

Background Recent malaria vector control measures have considerably reduced indoor biting mosquito populations. However, reducing the outdoor biting populations remains a challenge because of the unavailability of appropriate lures to achieve this. This study sought to test the efficacy of plant-based synthetic odor baits in trapping outdoor populations of malaria vectors. Methodology and Principal Finding Three plant-based lures ((E)-linalool oxide [LO], (E)-linalool oxide and (E)-β-ocimene [LO + OC], and a six-component blend comprising (E)-linalool oxide, (E)-β-ocimene, hexanal, β-pinene, limonene, and (E)-β-farnesene [Blend C]), were tested alongside an animal/human-based synthetic lure (comprising heptanal, octanal, nonanal, and decanal [Blend F]) and worn socks in a malaria endemic zone in the western part of Kenya. Mosquito Magnet-X (MM-X) and lightless Centre for Disease Control (CDC) light traps were used. Odor-baited traps were compared with traps baited with either solvent alone or solvent + carbon dioxide (controls) for 18 days in a series of randomized incomplete-block designs of days × sites × treatments. The interactive effect of plant and animal/human odor was also tested by combining LO with either Blend F or worn socks. Our results show that irrespective of trap type, traps baited with synthetic plant odors compared favorably to the same traps baited with synthetic animal odors and worn socks in trapping malaria vectors, relative to the controls. Combining LO and worn socks enhanced trap captures of Anopheles species while LO + Blend F recorded reduced trap capture. Carbon dioxide enhanced total trap capture of both plant- and animal/human-derived odors. However, significantly higher proportions of male and engorged female Anopheles gambiae s.l. were caught when the odor treatments did not include carbon dioxide. Conclusion and Significance The results highlight the potential of plant-based odors and specifically linalool oxide, with or

Development and assessment of plant-based synthetic odor baits for surveillance and control of malaria vectors.

PubMed

Nyasembe, Vincent O; Tchouassi, David P; Kirwa, Hillary K; Foster, Woodbridge A; Teal, Peter E A; Borgemeister, Christian; Torto, Baldwyn

2014-01-01

Recent malaria vector control measures have considerably reduced indoor biting mosquito populations. However, reducing the outdoor biting populations remains a challenge because of the unavailability of appropriate lures to achieve this. This study sought to test the efficacy of plant-based synthetic odor baits in trapping outdoor populations of malaria vectors. Three plant-based lures ((E)-linalool oxide [LO], (E)-linalool oxide and (E)-β-ocimene [LO + OC], and a six-component blend comprising (E)-linalool oxide, (E)-β-ocimene, hexanal, β-pinene, limonene, and (E)-β-farnesene [Blend C]), were tested alongside an animal/human-based synthetic lure (comprising heptanal, octanal, nonanal, and decanal [Blend F]) and worn socks in a malaria endemic zone in the western part of Kenya. Mosquito Magnet-X (MM-X) and lightless Centre for Disease Control (CDC) light traps were used. Odor-baited traps were compared with traps baited with either solvent alone or solvent + carbon dioxide (controls) for 18 days in a series of randomized incomplete-block designs of days × sites × treatments. The interactive effect of plant and animal/human odor was also tested by combining LO with either Blend F or worn socks. Our results show that irrespective of trap type, traps baited with synthetic plant odors compared favorably to the same traps baited with synthetic animal odors and worn socks in trapping malaria vectors, relative to the controls. Combining LO and worn socks enhanced trap captures of Anopheles species while LO + Blend F recorded reduced trap capture. Carbon dioxide enhanced total trap capture of both plant- and animal/human-derived odors. However, significantly higher proportions of male and engorged female Anopheles gambiae s.l. were caught when the odor treatments did not include carbon dioxide. The results highlight the potential of plant-based odors and specifically linalool oxide, with or without carbon dioxide, for surveillance and mass trapping of malaria vectors.

The effect of an anti-malarial subsidy programme on the quality of service provision of artemisinin-based combination therapy in Kenya: a cluster-randomized, controlled trial

PubMed Central

2013-01-01

Background Many patients with suspected malaria in sub-Saharan Africa seek treatment from private providers, but this sector suffers from sub-standard medicine dispensing practices. To improve the quality of care received for presumptive malaria from the highly accessed private retail sector in western Kenya, subsidized pre-packaged artemether-lumefantrine (AL) was provided to private retailers, together with a one day training for retail staff on malaria diagnosis and treatment, job aids and community engagement activities. Methods The intervention was assessed using a cluster-randomized, controlled design. Provider and mystery-shopper cross-sectional surveys were conducted at baseline and eight months post-intervention to assess provider practices. Data were analysed based on cluster-level summaries, comparing control and intervention arms. Results On average, 564 retail outlets were interviewed per year. At follow-up, 43% of respondents reported that at least one staff member had attended the training in the intervention arm. The intervention significantly increased the percentage of providers knowing the first line treatment for uncomplicated malaria by 24.2% points (confidence interval (CI): 14.8%, 33.6%; adjusted p=0.0001); the percentage of outlets stocking AL by 31.7% points (CI: 22.0%, 41.3%; adjusted p=0.0001); and the percentage of providers prescribing AL for presumptive malaria by 23.6% points (CI: 18.7%, 28.6%; adjusted p=0.0001). Generally outlets that received training and job aids performed better than those receiving one or none of these intervention components. Conclusion Overall, subsidizing ACT and retailer training can significantly increase the percentage of outlets stocking and selling AL for the presumptive treatment of malaria, but further research is needed on strategies to improve the provision of counselling advice to retail customers. PMID:23452547

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.

Raised temperatures over the Kericho tea estates: revisiting the climate in the East African highlands malaria debate

PubMed Central

2011-01-01

Background Whether or not observed increases in malaria incidence in the Kenyan Highlands during the last thirty years are associated with co-varying changes in local temperature, possibly connected to global changes in climate, has been debated for over a decade. Studies, using differing data sets and methodologies, produced conflicting results regarding the occurrence of temperature trends and their likelihood of being responsible, at least in part, for the increases in malaria incidence in the highlands of western Kenya. A time series of quality controlled daily temperature and rainfall data from Kericho, in the Kenyan Highlands, may help resolve the controversy. If significant temperature trends over the last three decades have occurred then climate should be included (along with other factors such as land use change and drug resistance) as a potential driver of the observed increases in malaria in the region. Methods Over 30 years (1 January 1979 to 31 December 2009) of quality controlled daily observations ( > 97% complete) of maximum, minimum and mean temperature were used in the analysis of trends at Kericho meteorological station, sited in a tea growing area of Kenya's western highlands. Inhomogeneities in all the time series were identified and corrected. Linear trends were identified via a least-squares regression analysis with statistical significance assessed using a two-tailed t-test. These 'gold standard' meteorological observations were compared with spatially interpolated temperature datasets that have been developed for regional or global applications. The relationship of local climate processes with larger climate variations, including tropical sea surface temperatures (SST), and El Niño-Southern Oscillation (ENSO) was also assessed. Results An upward trend of ≈0.2°C/decade was observed in all three temperature variables (P < 0.01). Mean temperature variations in Kericho were associated with large-scale climate variations including tropical

Raised temperatures over the Kericho tea estates: revisiting the climate in the East African highlands malaria debate.

PubMed

Omumbo, Judith A; Lyon, Bradfield; Waweru, Samuel M; Connor, Stephen J; Thomson, Madeleine C

2011-01-17

Whether or not observed increases in malaria incidence in the Kenyan Highlands during the last thirty years are associated with co-varying changes in local temperature, possibly connected to global changes in climate, has been debated for over a decade. Studies, using differing data sets and methodologies, produced conflicting results regarding the occurrence of temperature trends and their likelihood of being responsible, at least in part, for the increases in malaria incidence in the highlands of western Kenya. A time series of quality controlled daily temperature and rainfall data from Kericho, in the Kenyan Highlands, may help resolve the controversy. If significant temperature trends over the last three decades have occurred then climate should be included (along with other factors such as land use change and drug resistance) as a potential driver of the observed increases in malaria in the region. Over 30 years (1 January 1979 to 31 December 2009) of quality controlled daily observations ( > 97% complete) of maximum, minimum and mean temperature were used in the analysis of trends at Kericho meteorological station, sited in a tea growing area of Kenya's western highlands. Inhomogeneities in all the time series were identified and corrected. Linear trends were identified via a least-squares regression analysis with statistical significance assessed using a two-tailed t-test. These 'gold standard' meteorological observations were compared with spatially interpolated temperature datasets that have been developed for regional or global applications. The relationship of local climate processes with larger climate variations, including tropical sea surface temperatures (SST), and El Niño-Southern Oscillation (ENSO) was also assessed. An upward trend of ≈0.2°C/decade was observed in all three temperature variables (P < 0.01). Mean temperature variations in Kericho were associated with large-scale climate variations including tropical SST (r = 0.50; p < 0

Estimated burden of fungal infections in Kenya.

PubMed

Guto, John Abuga; Bii, Christine C; Denning, David W

2016-08-31

Kenya is a developing country with a high rate of tuberculosis (TB) and a moderate HIV infection burden. No estimate of the burden of fungal diseases in Kenya is published. We used specific populations at risk and fungal infection frequencies from the literature to estimate national incidence or prevalence of serious fungal infections. Used sources were: 2010 WHO TB statistics, Kenya Acquired Immunodeficiency Syndrome (AIDS) Epidemic Update 2012, Kenya Facts and figures 2012, Kenya Demographic and Health Survey 2008-2009. Of Kenya's population of ~40 million, 43% are under 15 years old and approximately 594,660 Kenyan women get >4 episodes Candida vulvovaginitis annually (2,988/100,000). The HIV/AIDS population at risk of opportunistic infections (OI) is 480,000 and the OI estimates include 306,000 patients with oral thrush (768/100,000), 114,000 with oesophageal candidiasis (286/100,000), 11,900 with cryptococcal meningitis (29/100,000) and 17,000 patients with Pneumocystis pneumonia (42/100,000). Chronic pulmonary aspergillosis following TB has a prevalence of 10,848 cases (32/100,000). The adult asthma prevalence is 3.1% and assuming 2.5% have allergic bronchopulmonary aspergillosis then 17,696 (44/100,000) are affected.  Invasive aspergillosis, candidaemia and Candida peritonitis are probably uncommon. Tinea capitis infects 9.6% of children in Kenya, while fungal keratitis and otomycoses are difficult to estimate. At any one time, about 7% of the Kenyan population suffers from a significant fungal infection, with recurrent vaginitis and tinea capitis accounting for 82% of the infections. These estimates require further epidemiological studies for validation.

A Seasonal Air Transport Climatology for Kenya

NASA Technical Reports Server (NTRS)

Gatebe, C. K.; Tyson, P. D.; Annegarn, H.; Piketh, S.; Helas, G.

1998-01-01

A climatology of air transport to and from Kenya has been developed using kinematic trajectory modeling. Significant months for trajectory analysis have been determined from a classification of synoptic circulation fields. Five-point back and forward trajectory clusters to and from Kenya reveal that the transport corridors to Kenya are clearly bounded and well defined. Air reaching the country originates mainly from the Saharan region and northwestern Indian Ocean of the Arabian Sea in the northern hemisphere and from the Madagascan region of the Indian Ocean in the southern hemisphere. Transport from each of these source regions show distinctive annual cycles related to the northeasterly Asian monsoon and the southeasterly trade wind maximum over Kenya in May. The Saharan transport in the lower troposphere is at a maximum when the subtropical high over northern Africa is strongly developed in the boreal winter. Air reaching Kenya between 700 and 500 hPa is mainly from Sahara and northwest India Ocean flows in the months of January and March, which gives way to southwest Indian Ocean flow in May and November. In contrast, air reaching Kenya at 400 hPa is mainly from southwest Indian Ocean in January and March, which is replaced by Saharan transport in May and November. Transport of air from Kenya is invariant, both spatially and temporally, in the tropical easterlies to the Congo Basin and Atlantic Ocean in comparison to the transport to the country. Recirculation of air has also been observed, but on a limited and often local scale and not to the extent reported in southern Africa.

Spectrum-Malaria: a user-friendly projection tool for health impact assessment and strategic planning by malaria control programmes in sub-Saharan Africa.

PubMed

Hamilton, Matthew; Mahiane, Guy; Werst, Elric; Sanders, Rachel; Briët, Olivier; Smith, Thomas; Cibulskis, Richard; Cameron, Ewan; Bhatt, Samir; Weiss, Daniel J; Gething, Peter W; Pretorius, Carel; Korenromp, Eline L

2017-02-10

Scale-up of malaria prevention and treatment needs to continue but national strategies and budget allocations are not always evidence-based. This article presents a new modelling tool projecting malaria infection, cases and deaths to support impact evaluation, target setting and strategic planning. Nested in the Spectrum suite of programme planning tools, the model includes historic estimates of case incidence and deaths in groups aged up to 4, 5-14, and 15+ years, and prevalence of Plasmodium falciparum infection (PfPR) among children 2-9 years, for 43 sub-Saharan African countries and their 602 provinces, from the WHO and malaria atlas project. Impacts over 2016-2030 are projected for insecticide-treated nets (ITNs), indoor residual spraying (IRS), seasonal malaria chemoprevention (SMC), and effective management of uncomplicated cases (CMU) and severe cases (CMS), using statistical functions fitted to proportional burden reductions simulated in the P. falciparum dynamic transmission model OpenMalaria. In projections for Nigeria, ITNs, IRS, CMU, and CMS scale-up reduced health burdens in all age groups, with largest proportional and especially absolute reductions in children up to 4 years old. Impacts increased from 8 to 10 years following scale-up, reflecting dynamic effects. For scale-up of each intervention to 80% effective coverage, CMU had the largest impacts across all health outcomes, followed by ITNs and IRS; CMS and SMC conferred additional small but rapid mortality impacts. Spectrum-Malaria's user-friendly interface and intuitive display of baseline data and scenario projections holds promise to facilitate capacity building and policy dialogue in malaria programme prioritization. The module's linking to the OneHealth Tool for costing will support use of the software for strategic budget allocation. In settings with moderately low coverage levels, such as Nigeria, improving case management and achieving universal coverage with ITNs could achieve

Avian and simian malaria: do they have a cancer connection?

PubMed

Ward, Martin; Benelli, Giovanni

2017-03-01

It has been claimed that infectious agents transmitted by mosquitoes (Diptera: Culicidae) may have a greater connection to cancer then hitherto supposed and that the immune system struggles to recognize and fight some of these infectious agents. One of the claims made is that there is a connection between human malaria and brain cancers in the USA. However, the USA declared itself free of human malaria in the last century, yet cancer incidences remain high, suggesting any overall cancer connection is slight. Two fundamental questions arise from the possible mosquito-cancer connection. Firstly, if mosquitoes are able to vector some pathogens and parasites linked with cancer pathogenesis, why has the fact not been discovered decades ago? Secondly, if there is a connection (other than in relation to Burkett's lymphoma), what is its extent? The answers may well lie with the various types of malarias known to exist. The discovery in humans of the simian malaria, caused by Plasmodium knowlesi, suggests that other forms of simian or even avian malaria may be capable of survival in humans, albeit at low levels of parasitemia, and humans may be a dead-end host. Other carcinogenic infectious agents transmitted by mosquitoes may also go undetected because either no one is looking for them, or they are looking in wrong anatomical locations and/or with inadequate tools. Research on false negative test results with respect to many infectious agents is sadly lacking, so its extent is unknown. However, electronic and other media provide numerous instances of patients failing to be diagnosed for both human malaria and Lyme's disease, to take just two examples. This review suggests that to shed light on a potential mosquito-cancer connection, more research is required to establish whether other simian and avian forms of malaria play a part. If so, then they potentially provide unique markers for early cancer detection.

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

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

The evil circle of poverty: a qualitative study of malaria and disability.

PubMed

Ingstad, Benedicte; Munthali, Alister C; Braathen, Stine H; Grut, Lisbet

2012-01-11

This article discusses the link between disability and malaria in a poor rural setting. Global malaria programmes and rehabilitation programmes are organized as vertical and separate programmes, and as such they focus on prevention, cure and control, and disability respectively. When looking at specific conditions and illnesses, the impairing long-term consequences of illness incidents during childhood are not questioned. The study design was ethnographic with an open, exploratory approach. Data were collected in Mangochi District in Malawi through qualitative in-depth interviews and participant observation. Despite a local-based health service system, people living in poor rural areas are confronted with a multitude of barriers when accessing malaria prevention and treatment. Lack of skilled health personnel and equipment add to the general burden of poverty: insufficient knowledge about health care, problems connected to accessing the health facility in time, insufficient initiatives to prevent malaria attacks, and a general lack of attention to the long term disabling effects of a malaria attack. This study points to the importance of building malaria programmes, research and statistics that take into consideration the consequences of permanent impairment after a malaria attack, as well as the context of poverty in which they often occur. In order to do so, one needs to develop methods for detecting people whose disabilities are a direct result of not having received health services after a malaria episode. This may be done through qualitative approaches in local communities and should also be supplemented by suitable surveys in order to estimate the problem on a larger scale. © 2012 Ingstad et al; licensee BioMed Central Ltd.

Performance of “VIKIA Malaria Ag Pf/Pan” (IMACCESS®), a new malaria rapid diagnostic test for detection of symptomatic malaria infections

PubMed Central

2012-01-01

Background Recently, IMACCESS® developed a new malaria test (VIKIA Malaria Ag Pf/Pan™), based on the detection of falciparum malaria (HRP-2) and non-falciparum malaria (aldolase). Methods The performance of this new malaria rapid diagnostic test (RDT) was assessed using 1,000 febrile patients seeking malaria treatment in four health centres in Cambodia from August to December 2011. The results of the VIKIA Malaria Ag Pf/Pan were compared with those obtained by microscopy, the CareStart Malaria™ RDT (AccessBio®) which is currently used in Cambodia, and real-time PCR (as “gold standard”). Results The best performances of the VIKIA Malaria Ag Pf/Pan™ test for detection of both Plasmodium falciparum and non-P. falciparum were with 20–30 min reading times (sensitivity of 93.4% for P. falciparum and 82.8% for non-P. falciparum and specificity of 98.6% for P. falciparum and 98.9% for non-P. falciparum) and were similar to those for the CareStart Malaria™ test. Conclusions This new RDT performs similarly well as other commercially available tests (especially the CareStart Malaria™ test, used as comparator), and conforms to the World Health Organization’s recommendations for RDT performance. It is a good alternative tool for the diagnosis of malaria in endemic areas. PMID:22920654

Modern malaria chemoprophylaxis.

PubMed

Shanks, G Dennis; Edstein, Michael D

2005-01-01

Currently available medications for malaria chemoprophylaxis are efficacious but the problems of patient compliance, the advance of parasite drug resistance, and real or perceived serious adverse effects mean that new chemical compounds are needed.Primaquine, which has been widely used to treat relapsing malaria since the 1950s, has been shown to prevent malaria when taken daily. Tafenoquine is a new 8-aminoquinoline with a much longer half-life than primaquine. Field trials to date indicate that tafenoquine is efficacious and can be taken weekly or perhaps even less frequently. Both primaquine and tafenoquine require exact knowledge of a person's glucose 6-phosphate dehydrogenase status in order to prevent drug-induced haemolysis. Other potential malaria chemoprophylactic drugs such as third-generation antifol compounds and Mannich bases have reached advanced preclinical testing. Mefloquine has been seen to cause serious neuropsychiatric adverse effects on rare occasions. Recent public controversy regarding reputedly common serious adverse effects has made many Western travellers unwilling to take mefloquine. Special risk groups exposed to malaria, such as long-term travellers, children, pregnant women, aircrew and those requiring unimpeded psychomotor reactions, migrants returning to visit malarious countries of origin and febrile persons who have returned from malaria endemic areas, all require a nuanced approach to the use of drugs to prevent malaria. The carrying of therapeutic courses of antimalarial drugs to be taken only if febrile illness develops is indicated in very few travellers despite its appeal to some who fear adverse effects more than they fear potentially lethal malaria infection. Travellers with a significant exposure to malaria require a comprehensive plan for prevention that includes anti-mosquito measures but which is still primarily be based on the regular use of efficacious antimalarial medications.

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.

A global model of malaria climate sensitivity: comparing malaria response to historic climate data based on simulation and officially reported malaria incidence.

PubMed

Edlund, Stefan; Davis, Matthew; Douglas, Judith V; Kershenbaum, Arik; Waraporn, Narongrit; Lessler, Justin; Kaufman, James H

2012-09-18

The role of the Anopheles vector in malaria transmission and the effect of climate on Anopheles populations are well established. Models of the impact of climate change on the global malaria burden now have access to high-resolution climate data, but malaria surveillance data tends to be less precise, making model calibration problematic. Measurement of malaria response to fluctuations in climate variables offers a way to address these difficulties. Given the demonstrated sensitivity of malaria transmission to vector capacity, this work tests response functions to fluctuations in land surface temperature and precipitation. This study of regional sensitivity of malaria incidence to year-to-year climate variations used an extended Macdonald Ross compartmental disease model (to compute malaria incidence) built on top of a global Anopheles vector capacity model (based on 10 years of satellite climate data). The predicted incidence was compared with estimates from the World Health Organization and the Malaria Atlas. The models and denominator data used are freely available through the Eclipse Foundation's Spatiotemporal Epidemiological Modeller (STEM). Although the absolute scale factor relating reported malaria to absolute incidence is uncertain, there is a positive correlation between predicted and reported year-to-year variation in malaria burden with an averaged root mean square (RMS) error of 25% comparing normalized incidence across 86 countries. Based on this, the proposed measure of sensitivity of malaria to variations in climate variables indicates locations where malaria is most likely to increase or decrease in response to specific climate factors. Bootstrapping measures the increased uncertainty in predicting malaria sensitivity when reporting is restricted to national level and an annual basis. Results indicate a potential 20x improvement in accuracy if data were available at the level ISO 3166-2 national subdivisions and with monthly time sampling. The

Clinical overlap between malaria and pneumonia: can malaria rapid diagnostic test play a role?

PubMed

Ukwaja, Kingsley Nnanna; Aina, Olufemi B; Talabi, Ademola A

2011-03-21

Malaria and pneumonia account for 40% of mortality among children under five years of age in sub-Saharan Africa. Due to lack of diagnostic facilities, their management is based on the integrated management of childhood illnesses (IMCI) strategy. Symptoms of malaria and pneumonia overlap in African children, necessitating dual IMCI classifications at health centres and treatment with both antibiotics and antimalarials. This study determined the prevalence of malaria-pneumonia symptom overlap and confirmed the diagnosis of malaria in these cases using a rapid diagnostic test. Consecutive consultations of 1,216 children (two months to five years old) were documented over a three-month period in a comprehensive health centre. Malaria rapid diagnostic tests were conducted only for children who had symptom overlap. Of the 1,216 children enrolled, 1,090 (90%) reported cough or fever. Among the children fulfilling the malaria case definition, 284 (30%) also met the pneumonia case definition. Twenty-three percent (284) of all children enrolled met the criteria for both malaria and pneumonia. However, only 130 (46%) of them had a positive result for malaria using a malaria rapid diagnostic test. During a malaria-pneumonia overlap, female children (chi-square 5.9, P = 0.01) and children ≥ one year (chi-square 4.8, P = 0.003) were more likely to seek care within two days of fever. Dual treatment with antimalarials and antibiotics in children with malaria-pneumonia overlap may result in unnecessary over-prescription of antimalarial medications. Use of rapid diagnostic tests in their management can potentially avoid over-prescribing of malaria medications.

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.

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

Topographic models for predicting malaria vector breeding habitats: potential tools for vector control managers.

PubMed

Nmor, Jephtha C; Sunahara, Toshihiko; Goto, Kensuke; Futami, Kyoko; Sonye, George; Akweywa, Peter; Dida, Gabriel; Minakawa, Noboru

2013-01-16

Identification of malaria vector breeding sites can enhance control activities. Although associations between malaria vector breeding sites and topography are well recognized, practical models that predict breeding sites from topographic information are lacking. We used topographic variables derived from remotely sensed Digital Elevation Models (DEMs) to model the breeding sites of malaria vectors. We further compared the predictive strength of two different DEMs and evaluated the predictability of various habitat types inhabited by Anopheles larvae. Using GIS techniques, topographic variables were extracted from two DEMs: 1) Shuttle Radar Topography Mission 3 (SRTM3, 90-m resolution) and 2) the Advanced Spaceborne Thermal Emission Reflection Radiometer Global DEM (ASTER, 30-m resolution). We used data on breeding sites from an extensive field survey conducted on an island in western Kenya in 2006. Topographic variables were extracted for 826 breeding sites and for 4520 negative points that were randomly assigned. Logistic regression modelling was applied to characterize topographic features of the malaria vector breeding sites and predict their locations. Model accuracy was evaluated using the area under the receiver operating characteristics curve (AUC). All topographic variables derived from both DEMs were significantly correlated with breeding habitats except for the aspect of SRTM. The magnitude and direction of correlation for each variable were similar in the two DEMs. Multivariate models for SRTM and ASTER showed similar levels of fit indicated by Akaike information criterion (3959.3 and 3972.7, respectively), though the former was slightly better than the latter. The accuracy of prediction indicated by AUC was also similar in SRTM (0.758) and ASTER (0.755) in the training site. In the testing site, both SRTM and ASTER models showed higher AUC in the testing sites than in the training site (0.829 and 0.799, respectively). The predictability of habitat types

Migration and Malaria in Europe

PubMed Central

Monge-Maillo, Begoña; López-Vélez, Rogelio

2012-01-01

The proportion of imported malaria cases due to immigrants in Europe has increased during the lasts decades, with higher rates associated with settled immigrants who travel to visit friends and relatives (VFRs) in their country of origin. Cases are mainly due to P. falciparum and Sub-Saharan Africa is the most common origin. Clinically, malaria in immigrants is characterised by a mild clinical presentation including asymptomatic or delayed malaria cases and low parasitic levels. These characteristics may be explained by a semi-immunity acquired after long periods of time exposed to stable malaria transmission. Malaria cases among immigrants, even asymptomatic patients with sub-microscopic parasitemia, could increase the risk of transmission and cause the reintroduction of malaria in certain areas that have adequate vectors and climate conditions. Moreover, imported malaria cases in immigrants can also play an important role in the non-vector transmission out of endemic areas, through blood transfusions, organ transplantation or congenital transmission or occupational exposures. Consequently, outside of endemic areas, malaria screening should be carried out among recently arrived immigrants coming from malaria endemic countries. The aim of screening is to reduce the risk of clinical malaria in the individual as well as to prevent autochthonous transmission of malaria in areas where it has been eradicated. PMID:22536477

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

Genetic determinants of glucose-6-phosphate dehydrogenase activity in Kenya

PubMed Central

2014-01-01

Background The relationship between glucose-6-phosphate dehydrogenase (G6PD) deficiency and clinical phenomena such as primaquine-sensitivity and protection from severe malaria remains poorly defined, with past association studies yielding inconsistent and conflicting results. One possibility is that examination of a single genetic variant might underestimate the presence of true effects in the presence of unrecognized functional allelic diversity. Methods We systematically examined this possibility in Kenya, conducting a fine-mapping association study of erythrocyte G6PD activity in 1828 Kenyan children across 30 polymorphisms at or around the G6PD locus. Results We demonstrate a strong functional role for c.202G>A (rs1050828), which accounts for the majority of variance in enzyme activity observed (P=1.5×10−200, additive model). Additionally, we identify other common variants that exert smaller, intercorrelated effects independent of c.202G>A, and haplotype analyses suggest that each variant tags one of two haplotype motifs that are opposite in sequence identity and effect direction. We posit that these effects are of biological and possible clinical significance, specifically noting that c.376A>G (rs1050829) augments 202AG heterozygote risk for deficiency trait by two-fold (OR = 2.11 [1.12 - 3.84], P=0.014). Conclusions Our results suggest that c.202G>A is responsible for the majority of the observed prevalence of G6PD deficiency trait in Kenya, but also identify a novel role for c.376A>G as a genetic modifier which marks a common haplotype that augments the risk conferred to 202AG heterozygotes, suggesting that variation at both loci merits consideration in genetic association studies probing G6PD deficiency-associated clinical phenotypes. PMID:25201310

Genetic determinants of glucose-6-phosphate dehydrogenase activity in Kenya.

PubMed

Shah, Shivang S; Macharia, Alex; Makale, Johnstone; Uyoga, Sophie; Kivinen, Katja; Craik, Rachel; Hubbart, Christina; Wellems, Thomas E; Rockett, Kirk A; Kwiatkowski, Dominic P; Williams, Thomas N

2014-09-09

The relationship between glucose-6-phosphate dehydrogenase (G6PD) deficiency and clinical phenomena such as primaquine-sensitivity and protection from severe malaria remains poorly defined, with past association studies yielding inconsistent and conflicting results. One possibility is that examination of a single genetic variant might underestimate the presence of true effects in the presence of unrecognized functional allelic diversity. We systematically examined this possibility in Kenya, conducting a fine-mapping association study of erythrocyte G6PD activity in 1828 Kenyan children across 30 polymorphisms at or around the G6PD locus. We demonstrate a strong functional role for c.202G>A (rs1050828), which accounts for the majority of variance in enzyme activity observed (P=1.5×10⁻²⁰⁰, additive model). Additionally, we identify other common variants that exert smaller, intercorrelated effects independent of c.202G>A, and haplotype analyses suggest that each variant tags one of two haplotype motifs that are opposite in sequence identity and effect direction. We posit that these effects are of biological and possible clinical significance, specifically noting that c.376A>G (rs1050829) augments 202AG heterozygote risk for deficiency trait by two-fold (OR = 2.11 [1.12 - 3.84], P=0.014). Our results suggest that c.202G>A is responsible for the majority of the observed prevalence of G6PD deficiency trait in Kenya, but also identify a novel role for c.376A>G as a genetic modifier which marks a common haplotype that augments the risk conferred to 202AG heterozygotes, suggesting that variation at both loci merits consideration in genetic association studies probing G6PD deficiency-associated clinical phenotypes.

Kenya's Maligned African Press: A Reassessment.

ERIC Educational Resources Information Center

Scotton, James F.

Kenya's dozen or more newspapers and 50 news sheets edited and published by Africans in the turbulent 1945-52 preindependence period were condemned as irresponsible, inflammatory, antiwhite, and seditious by the Kenya colonial government, and this characterization has been accepted by many scholars and journalists, including Africans. There is…

Malaria.

PubMed

Ashley, Elizabeth A; Pyae Phyo, Aung; Woodrow, Charles J

2018-04-21

Following unsuccessful eradication attempts there was a resurgence of malaria towards the end of the 20th century. Renewed control efforts using a range of improved tools, such as long-lasting insecticide-treated bednets and artemisinin-based combination therapies, have more than halved the global burden of disease, but it remains high with 445 000 deaths and more than 200 million cases in 2016. Pitfalls in individual patient management are delayed diagnosis and overzealous fluid resuscitation in severe malaria. Even in the absence of drug resistance, parasite recurrence can occur, owing to high parasite densities, low host immunity, or suboptimal drug concentrations. Malaria elimination is firmly back as a mainstream policy but resistance to the artemisinin derivatives, their partner drugs, and insecticides present major challenges. Vaccine development continues on several fronts but none of the candidates developed to date have been shown to provide long-lasting benefits at a population level. Increased resources and unprecedented levels of regional cooperation and societal commitment will be needed if further substantial inroads into the malaria burden are to be made. Copyright © 2018 Elsevier Ltd. All rights reserved.

Reduction in malaria prevalence and increase in malaria awareness in endemic districts of Bangladesh.

PubMed

Alam, Mohammad Shafiul; Kabir, Mohammad Moktadir; Hossain, Mohammad Sharif; Naher, Shamsun; Ferdous, Nur E Naznin; Khan, Wasif Ali; Mondal, Dinesh; Karim, Jahirul; Shamsuzzaman, A K M; Ahmed, Be-Nazir; Islam, Akramul; Haque, Rashidul

2016-11-11

Malaria is endemic in 13 districts of Bangladesh. A baseline malaria prevalence survey across the endemic districts of Bangladesh was conducted in 2007, when the prevalence was reported around 39.7 per 1000 population. After two rounds of Global Fund to Fight AIDS, Tuberculosis and Malaria (GFATM)-funded intervention by the National Malaria Control Programme (NMCP) and a BRAC-led NGO consortium, a follow-up survey was conducted across the malaria-endemic districts of Bangladesh to measure the change in prevalence rate and in people's knowledge of malaria. The survey was carried out from August to November 2013 in 70 upazilas (sub-districts) of 13 malaria-endemic districts of Bangladesh, following the same multi-stage cluster sampling design and the same number of households enrolled during the baseline prevalence survey in 2007, to collect 9750 randomly selected blood samples. For on-the-spot diagnosis of malaria, a rapid diagnostic test was used. The household head or eldest person available was interviewed using a pre-coded structured questionnaire to collect data on the knowledge and awareness of malaria in the household. Based on a weighted calculation, the overall malaria prevalence was found to be 1.41 per 1000 population. The proportion of Plasmodium falciparum mono-infection was 77.78% while both Plasmodium vivax mono-infection and mixed infection of the two species were found to be 11.11%. Bandarban had the highest prevalence (6.67 per 1000 population). Knowledge of malaria signs, symptoms and mode of transmission were higher in the follow-up survey (97.26%) than the baseline survey. Use of bed nets for prevention of malaria was found to be high (90.15%) at respondent level. People's knowledge of selected parameters increased significantly during the follow-up survey compared to the baseline survey conducted in 2007. A reduced prevalence rate of malaria and increased level of knowledge were observed in the present malaria prevalence survey in Bangladesh.

[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.

Early life exposure to malaria and cognition in adulthood: evidence from Mexico.

PubMed

Venkataramani, Atheendar S

2012-09-01

This study examines the impact of early life malaria exposure on cognition in sample of Mexican adults, using the nationwide introduction of malaria eradication efforts to identify causal impacts. The core findings are that birth year exposure to malaria eradication was associated with increases in Raven Progressive Matrices test scores and consumption expenditures, but not schooling. Additionally, cohorts born after eradication both entered and exited school earlier than their pre-eradication counterparts. These effects were only seen for men and explanations for this are assessed. Collectively, these findings suggest that improvements in infant health help explain secular increases in cognitive test scores, that better cognition may link early life health to adulthood earnings, and that human capital investments through childhood and young adulthood respond sensitively to market returns to early life endowment shocks. Copyright © 2012 Elsevier B.V. All rights reserved.

Larvivorous fish for preventing malaria transmission.

PubMed

Walshe, Deirdre P; Garner, Paul; Adeel, Ahmed A; Pyke, Graham H; Burkot, Thomas R

2017-12-11

adult anopheline population. In the absence of direct evidence of an effect on transmission, we performed a secondary analysis on studies that evaluated the effect of introducing larvivorous fish on the density or presence of immature anopheline mosquitoes (larvae and pupae forms) in water sources to determine whether this intervention has any potential that may justify further research in the control of malaria vectors. Two review authors independently screened each article by title and abstract, and examined potentially relevant studies for inclusion using an eligibility form. At least two review authors independently extracted data and assessed risk of bias of included studies. If relevant data were unclear or were not reported, we contacted the study authors for clarification. We presented data in tables, and we summarized studies that evaluated the effects of introducing fish on anopheline immature density or presence, or both. We used the GRADE approach to summarize the certainty of the evidence. We also examined whether the included studies reported any possible adverse impact of introducing larvivorous fish on non-target native species. We identified no studies that reported the effects of introducing larvivorous fish on the primary outcomes of this review: malaria infection in nearby communities, entomological inoculation rate, or on adult Anopheles density.For the secondary analysis, we examined the effects of introducing larvivorous fish on the density and presence of anopheline larvae and pupae in community water sources, and found 15 small studies with a follow-up period between 22 days and five years. These studies were undertaken in Sri Lanka (two studies), India (three studies), Ethiopia (one study), Kenya (two studies), Sudan (one study), Grande Comore Island (one study), Korea (two studies), Indonesia (one study), and Tajikistan (two studies). These studies were conducted in a variety of settings, including localized water bodies (such as wells

Burden of physical, psychological and social ill-health during and after pregnancy among women in India, Pakistan, Kenya and Malawi.

PubMed

McCauley, Mary; Madaj, Barbara; White, Sarah A; Dickinson, Fiona; Bar-Zev, Sarah; Aminu, Mamuda; Godia, Pamela; Mittal, Pratima; Zafar, Shamsa; van den Broek, Nynke

2018-01-01

For every woman who dies during pregnancy and childbirth, many more suffer ill-health, the burden of which is highest in low-resource settings. We sought to assess the extent and types of maternal morbidity. Descriptive observational cross-sectional study at primary-level and secondary-level healthcare facilities in India, Pakistan, Kenya and Malawi to assess physical, psychological and social morbidity during and after pregnancy. Sociodemographic factors, education, socioeconomic status (SES), quality of life, satisfaction with health, reported symptoms, clinical examination and laboratory investigations were assessed. Relationships between morbidity and maternal characteristics were investigated using multivariable logistic regression analysis. 11 454 women were assessed in India (2099), Malawi (2923), Kenya (3145), and Pakistan (3287). Almost 3 out of 4 women had ≥1 symptoms (73.5%), abnormalities on clinical examination (71.3%) or laboratory investigation (73.5%). In total, 36% of women had infectious morbidity of which 9.0% had an identified infectious disease (HIV, malaria, syphilis, chest infection or tuberculosis) and an additional 32.5% had signs of early infection. HIV-positive status was highest in Malawi (14.5%) as was malaria (10.4%). Overall, 47.9% of women were anaemic, 11.5% had other medical or obstetric conditions, 25.1% reported psychological morbidity and 36.6% reported social morbidity (domestic violence and/or substance misuse). Infectious morbidity was highest in Malawi (56.5%) and Kenya (40.4%), psychological and social morbidity was highest in Pakistan (47.3%, 60.2%). Maternal morbidity was not limited to a core at-risk group; only 1.2% had all four morbidities. The likelihood of medical or obstetric, psychological or social morbidity decreased with increased education; adjusted OR (95% CI) for each additional level of education ranged from 0.79 (0.75 to 0.83) for psychological morbidity to 0.91 (0.87 to 0.95) for infectious morbidity

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.

Review of Malaria Epidemics in Ethiopia using Enhanced Climate Services (ENACTS)

NASA Astrophysics Data System (ADS)

Muhammad, A.

2015-12-01

Malaria is a disease directly linked to temperature and rainfall. In Ethiopia, the influence of climate variables on malaria transmission and the subsequent role of ENSO in the rise of malaria incidence are becoming more recognized. Numerous publications attest to the extreme sensitivity of malaria to climate in Ethiopia. The majority of large-scale epidemics in the past were associated with climatic factors such as temperature and rainfall. However, there is limited information on climate variability and ENSO at the district level to aid in public health decision-making. Since 2008, the National Meteorogy Agency (NMA) and the International Research Institute for Climate and Society (IRI) have been collaborating on improving climate services in Ethiopia. This collaboration spurred the implementation of the Enhancing National Climate Services (ENACTS) initiative and the creation of the IRI Data Library (DL) NMA Ethiopia Maproom. ENACTS provides reliable and readily accessible climate data at high resolutions and the Maproom uses ENACTS to build a collection of maps and other figures that monitor climate and societal conditions at present and in the recent past (1981-2010). A recent analysis exploring the relationship of rainfall and temperature ENACTS products to malaria epidemics in proceeding rainy seasons within 12 woredas found above normal temperature anomalies to be more readily associated with epidemics when compared to above normal rainfall anomalies, regardless of the ENSO phase (Figure 1-2).

Evidence and Implications of Mortality Associated with Acute Plasmodium vivax Malaria

PubMed Central

2013-01-01

Vivax malaria threatens patients despite relatively low-grade parasitemias in peripheral blood. The tenet of death as a rare outcome, derived from antiquated and flawed clinical classifications, disregarded key clinical evidence, including (i) high rates of mortality in neurosyphilis patients treated with vivax malaria; (ii) significant mortality from zones of endemicity; and (iii) the physiological threat inherent in repeated, very severe paroxysms in any patient, healthy or otherwise. The very well-documented course of this infection, with the exception of parasitemia, carries all of the attributes of “perniciousness” historically linked to falciparum malaria, including severe disease and fatal outcomes. A systematic analysis of the parasite biomass in severely ill patients that includes blood, marrow, and spleen may ultimately explain this historic misunderstanding. Regardless of how this parasite is pernicious, recent data demonstrate that the infection comes with a significant burden of morbidity and associated mortality. The extraordinary burden of malaria is not heavily weighted upon any single continent by a single species of parasite—it is a complex problem for the entire endemic world, and both species are of fundamental importance. Humanity must rally substantial resources, intellect, and energy to counter this daunting but profound threat. PMID:23297258

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

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

Limitations of malaria reactive case detection in an area of low and unstable transmission on the Myanmar-Thailand border.

PubMed

Parker, Daniel M; Landier, Jordi; von Seidlein, Lorenz; Dondorp, Arjen; White, Lisa; Hanboonkunupakarn, Borimas; Maude, Richard J; Nosten, François H

2016-11-25

Reactive case detection is an approach that has been proposed as a tool for malaria elimination in low-transmission settings. It is an intuitively justified approach based on the concept of space-time clustering of malaria cases. When an index malaria clinical case is detected, it triggers reactive screening and treatment in the index house and neighbouring houses. However, the efficacy of this approach at varying screening radii and malaria prevalence remains ill defined. Data were obtained from a detailed demographic and geographic surveillance study in four villages on the Myanmar-Thailand border. Clinical cases were recorded at village malaria clinics and were linked back to patients' residencies. These data were used to simulate the efficacy of reactive case detection for clinical cases using rapid diagnostic tests (RDT). Simulations took clinical cases in a given month and tabulated the number of cases that would have been detected in the following month at varying screening radii around the index houses. Simulations were run independently for both falciparum and vivax malaria. Each simulation of a reactive case detection effort was run in comparison with a strategy using random selection of houses for screening. In approximately half of the screenings for falciparum and 10% for vivax it would have been impossible to detect any malaria cases regardless of the screening strategy because the screening would have occurred during times when there were no cases. When geographically linked cases were present in the simulation, reactive case detection would have only been successful at detecting most malaria cases using larger screening radii (150-m radius and above). At this screening radius and above, reactive case detection does not perform better than random screening of an equal number of houses in the village. Screening within very small radii detects only a very small proportion of cases, but despite this low performance is better than random screening with

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.

Life-table analysis of Anopheles arabiensis in western Kenya highlands: effects of land covers on larval and adult survivorship.

PubMed

Afrane, Yaw A; Zhou, Goufa; Lawson, Bernard W; Githeko, Andrew K; Yan, Guiyun

2007-10-01

In high-elevation areas in western Kenya, the abundance of Anopheles arabiensis is either very low or absent. The western Kenya highlands (an area with an elevation > 1,500m above sea level) have also been experiencing extensive deforestation, and deforestation has been suggested as one of the important factors that facilitate malaria transmission in the highlands. This study investigated whether climate conditions in the western Kenya highlands (Kakamega, elevation 1,500 m above sea level) were permissive to the development and survival of An. arabiensis and whether deforestation promoted An. arabiensis survivorship of immature and adult stages, using life-table analysis. We found that in larval habitats located in forested areas, only 4-9% of first-instar larvae developed into adults and the development length exceeded 20 days. Mean water temperature of aquatic habitats in the deforested area was 4.8-6.1 degrees C higher than that in the forested area, larval-to-adult survivorship was increased to 65-82%, and larval-to-adult development time was shortened by 8-9 days. The average indoor temperature in houses in the deforested area was 1.7-1.8 degrees C higher than in the forested area, and the relative humidity was 22-25% lower. The median survival time of adult mosquitoes in the deforested area was 49-55% higher than those in the forested area. The net reproductive rate of female mosquitoes in the deforested area was 1.7- to 2.6-fold higher than that in the forested area. Compared with previously published data on An. gambiae, the net reproductive rate of An. arabiensis was only 0.8-1.3% of Anopheles gambiae in the forested area and 2.3-2.6% in the deforested area. Therefore, the current ambient climate condition is less permissive to An. arabiensis than to An. gambiae in western Kenya highlands. However, environmental changes such as deforestation and global warming may facilitate the establishment of An. arabiensis populations in the highlands.

Accuracy of rapid tests for malaria and treatment outcomes for malaria and non-malaria cases among under-five children in rural Ghana.

PubMed

Baiden, Frank; Webster, Jayne; Tivura, Mathilda; Delimini, Rupert; Berko, Yvonne; Amenga-Etego, Seeba; Agyeman-Budu, Akua; Karikari, Akosua B; Bruce, Jane; Owusu-Agyei, Seth; Chandramohan, Daniel

2012-01-01

WHO now recommends test-based management of malaria across all transmission settings. The accuracy of rapid diagnostic test (RDT) and the outcome of treatment based on the result of tests will influence acceptability of and adherence to the new guidelines. We conducted a study at the Kintampo hospital in rural Ghana to evaluate the performance of CareStart, a HRP-2 based RDT, using microscopy as reference. We applied IMCI treatment guidelines, restricted ACT to RDT-positive children and followed-up both RDT-positive (malaria) and RDT-negative (non-malaria) cases over 28 days. 436 children were enrolled in the RDT evaluation and 391 (children with haemoglobin >8.0 gm/dl) were followed-up to assess treatment outcomes. Mean age was 25.4 months (s.d. 14.6). Sensitivity and specificity of the RDT were 100.0% and 73.0% respectively. Over the follow-up period, 32 (18.5%) RDT-negative children converted to positive, with 7 (4.0%) of them presenting with fever. More children in the non-malaria group made unscheduled visits than children in the malaria group (13.3% versus 7.7%) On all scheduled follow-up visits, proportion of children having a temperature higher than that recorded on day 0 was higher in the non-malaria group compared to the malaria group. Reports of unfavourable treatment outcomes by caregivers were higher among the non-malaria group than the malaria group. The RDT had good sensitivity and specificity. However a minority of children who will not receive ACT based on RDT results may develop clinical malaria within a short period in high transmission settings. This could undermine caregivers' and health workers' confidence in the new guidelines. Improving the quality of management of non-malarial febrile illnesses should be a priority in the era of test-based management of malaria. ClinicalTrials.gov NCT00832754.

Malaria, Epstein-Barr virus infection and the pathogenesis of Burkitt's lymphoma.

PubMed

Mawson, Anthony R; Majumdar, Suvankar

2017-11-01

A geographical and causal connection has long been recognized between malaria, Epstein-Barr virus (EBV) infection and Burkitt's lymphoma (BL), but the underlying mechanisms remain obscure. Potential clues are that the malaria parasite Plasmodium falciparum selectively absorbs vitamin A from the host and depends on it for its biological activities; secondly, alterations in vitamin A (retinoid) metabolism have been implicated in many forms of cancer, including BL. The first author has proposed that the merozoite-stage malaria parasite, emerging from the liver, uses its absorbed vitamin A as a cell membrane destabilizer to invade the red blood cells, causing anemia and other signs and symptoms of the disease as manifestations of an endogenous form of hypervitaminosis A (Mawson AR, Path Global Health 2013;107(3):122-9). Repeated episodes of malaria would therefore be expected to expose the tissues of affected individuals to potentially toxic doses of vitamin A. It is proposed that such episodes activate latent EBV infection, which in turn activates retinoid-responsive genes. Expression of these genes enhances viral replication and induces germinal center (GC) B cell expansion, activation-induced cytidine deaminase (AID) expression, and c-myc translocation, which in turn predisposes to BL. Thus, an endogenous form of retinoid toxicity related to malaria infection may be the common factor linking frequent malaria, EBV infection and BL, whereby prolonged exposure of lymphatic tissues to high concentrations of retinoids may combine to induce B-cell translocation and increase the risk of Burkitt's lymphoma. © 2017 UICC.

The effect of facility-based antiretroviral therapy programs on outpatient services in Kenya and Uganda.

PubMed

Wollum, Alexandra; Dansereau, Emily; Fullman, Nancy; Achan, Jane; Bannon, Kelsey A; Burstein, Roy; Conner, Ruben O; DeCenso, Brendan; Gasasira, Anne; Haakenstad, Annie; Hanlon, Michael; Ikilezi, Gloria; Kisia, Caroline; Levine, Aubrey J; Masters, Samuel H; Njuguna, Pamela; Okiro, Emelda A; Odeny, Thomas A; Allen Roberts, D; Gakidou, Emmanuela; Duber, Herbert C

2017-08-16

Considerable debate exists concerning the effects of antiretroviral therapy (ART) service scale-up on non-HIV services and overall health system performance in sub-Saharan Africa. In this study, we examined whether ART services affected trends in non-ART outpatient department (OPD) visits in Kenya and Uganda. Using a nationally representative sample of health facilities in Kenya and Uganda, we estimated the effect of ART programs on OPD visits from 2007 to 2012. We modeled the annual percent change in non-ART OPD visits using hierarchical mixed-effects linear regressions, controlling for a range of facility characteristics. We used four different constructs of ART services to capture the different ways in which the presence, growth, overall, and relative size of ART programs may affect non-ART OPD services. Our final sample included 321 health facilities (140 in Kenya and 181 in Uganda). On average, OPD and ART visits increased steadily in Kenya and Uganda between 2007 and 2012. For facilities where ART services were not offered, the average annual increase in OPD visits was 4·2% in Kenya and 13·5% in Uganda. Among facilities that provided ART services, we found average annual OPD volume increases of 7·2% in Kenya and 5·6% in Uganda, with simultaneous annual increases of 13·7% and 12·5% in ART volumes. We did not find a statistically significant relationship between annual changes in OPD services and the presence, growth, overall, or relative size of ART services. However, in a subgroup analysis, we found that Ugandan hospitals that offered ART services had statistically significantly less growth in OPD visits than Ugandan hospitals that did not provide ART services. Our findings suggest that ART services in Kenya and Uganda did not have a statistically significant deleterious effects on OPD services between 2007 and 2012, although subgroup analyses indicate variation by facility type. Our findings are encouraging, particularly given recent recommendations

[Plasmodium malariae malaria with more than a 4-month incubation period: difficult to distinguish from a relapse of Plasmodium vivax malaria].

PubMed

Hase, Ryota; Uwamino, Yoshifumi; Muranaka, Kiyoharu; Tochitani, Kentaro; Sogi, Misa; Kitazono, Hidetaka; Hosokawa, Naoto

2013-07-01

We report herein on a case of Plasmodium malariae malaria with more than a 4-month incubation period. A 35-year-old Japanese man who first presented to our clinic with fever and history of travel to Papua New Guinea was suspected of having Plasmodium vivax malaria based on peripheral smear results. We admitted him and initiated treatment with mefloquine. After two days of therapy, he became afebrile. We discharged him, and P. vivax was later confirmed with PCR. We started mefloquine prophylaxis for a planned trip to Papua New Guinea. After his return, a standard dose of primaquine (15 mg x 14 days) was prescribed for a radical cure of P. vivax. About 4 months after his last visit to Papua New Guinea, he returned to our clinic with fever. We suspected a relapse of P. vivax malaria and admitted him for a second time. After two days of mefloquine therapy, his symptoms improved. We discharged him and restarted a higher dose of primaquine (30 mg x 14 days) therapy for a radical cure of P. vivax. Subsequently, the PCR test revealed the parasite was P. malariae and not P. vivax. Only 13 cases of Plasmodium malariae malaria have been reported in Japan during the past 10 years. Blood-stage schizonticides such as mefloquine is not active against the liver stage. Therefore, the use of these drugs for prophylaxis will not be effective for prevention of malaria if its liver stage is longer than the duration of effective chemoprophylaxis. Although the incubation period of P. malariae is typically 13 to 28 days, it occasionally lasts for months or even years. Careful attention should be given to the possibility that P. malariae occasionally has a long incubation period even in the absence of the hypnozoite stage.

[Current malaria situation in the Republic of Uzbekistan].

PubMed

Razakov, Sh A; Shakhgunova, G Sh

2001-01-01

1998). The remaining cases were diagnosed as having acute respiratory viral infections, tropical and parasitic diseases, viral hepatitis, or influenza. Early diagnosis of malaria was made in 60% of cases (77% in 1998). Three cases of imported tertian malaria were recorded in the Tashkent Region in the first quarter of 2000. They were imported from Tajikistan into rural areas and the patients had been infected during the 1999 season. Epidemiological surveillance of malaria in Uzbekistan is regularly carried out by the general network of health facilities and by the departments of parasitology of state epidemiological surveillance centers in collaboration with medical administrative departments, the Ministry of Agriculture and Fisheries, the L.M. Isayev Research Institute of Medical Parasitology, and other agencies. Active links are maintained with WHO under the Roll Back Malaria programme. Great emphasis is laid on medical staff training at all levels. During the 1999 epidemiological survey, 672,536 laboratory tests were performed on blood samples from suspected malaria patients and individuals who had visited malaria-endemic countries, 55% of them suffering from fever. A total area of 17 million m2 of dwelling and nondwelling buildings 20 ha of water areas were treated against mosquitoes and the larvivorous fish Gambusia was put into the water areas occupying 6,500 ha. In all cases of malaria, the focus of infection was epidemiologically surveyed and required epidemic preventive measures were implemented. All malaria patients received a full course of radical therapy and recovered completely. The epidemiological surveillance system for malaria is affected by staff shortages at the parasitology departments of state epidemiological surveillance centers and by shortages of microscopes, reagents, sterilizing equipment, insecticides, etc. There are still difficulties in obtaining supplies of primaquine although a small stock is locally available as due to WHO humanitarian

Epidemiological situation of malaria in South East Asia with focus on India.

PubMed

Garg, B S

1997-12-01

Malaria contributes a most stimulating chapter in the annals of biological parasitism. At present the disease is endemic in 91 countries with about 40% of world population at risk. Among all infections malaria continues to be one of the biggest contributors to disease burden in terms of morbidity, suffering and deaths specially in Africa. By lowering the productivity it is closely linked to poverty and contributes significantly to stunting social and economic development.We, in South East Asia, are living in paradoxical situation, on one side we spent large sums and energy to control/eradicate malaria and on the other hand we simultaneously create malariogenic conditions in the process of development efforts eg. irrigation canals, water supply scheme and urbanisation.The disease is endemic in all the seven countries of South East Asia with P.f.% ranging from 2.47% in Nepaa to 55% in Pakistan. In India although the total number of cases are almost static in last 10 years however the P.f. cases are on increasing trend.The malaria in tribal area is further posing a great threat. Annually 0.2% of the population suffers with malaria. However it is 1.5% in tribal area and 60% of deaths due to malaria are reported from tribal area. In 1984 there were 24% cases ofP. falciparum malaria out of them 57% were in tribal area however in 1995 the total cases increased to 36% and P.f. proportion to 75%. Technical side the chloroquine resistance and insecticidal resistance are also spreading in new area which also complicate the disease epidemiology.The migration of population, deforestation, inadequate resources increase in epidemic potential and neglect of epidemiology are other important factors responsible for changing epidemiological pattern of malaria.

Transfusion-transmitted malaria in Ghana.

PubMed

Owusu-Ofori, Alex K; Betson, Martha; Parry, Christopher M; Stothard, J Russell; Bates, Imelda

2013-06-01

In sub-Saharan Africa, the prevalence of malaria parasitemia in blood donors varies from 0.6% to 50%. Although the burden of TTM in malaria-endemic countries is unknown, it is recommended that all donated blood is screened for malaria parasites. This study aimed to establish the incidence of TTM and identify a suitable screening test. Pregnant women, children, and immunocompromised malaria-negative transfusion recipients in a teaching hospital in Ghana were recruited over the course of 1 year. Parasites detected in recipients within 14 days of the transfusion were genotyped and compared to parasites in the transfused blood. The presence of genotypically identical parasites in the recipient and the transfused blood confirmed transfusion-transmitted malaria. Four malaria screening tests were compared to assess their usefulness in the context of African blood banks. Of the 50 patients who received transfusions that were positive for Plasmodium falciparum by polymerase chain reaction (PCR), 7 recipients developed PCR-detectable parasitemia. In only 1 of the 50 recipients (2%) was the parasite identical to that in the transfused blood. The prevalence of P. falciparum malaria in transfused blood was 4.7% (21/445) by microscopy, 13.7% (60/440) by rapid diagnostic test, 18% (78/436) by PCR, and 22.2% (98/442) by enzyme immunoassay. Although malaria parasites are commonly detected in blood donors in malaria-endemic areas, transfusion-transmitted malaria occurs infrequently. Policies recommend screening blood donors for malaria, but none of the commonly used methods is sufficiently sensitive to be used by blood banks in malaria-endemic countries.

Maternal Malaria and Gravidity Interact to Modify Infant Susceptibility to Malaria

PubMed Central

Mutabingwa, Theonest K; Bolla, Melissa C; Li, Jin-Long; Domingo, Gonzalo J; Li, Xiaohong; Fried, Michal; Duffy, Patrick E

2005-01-01

Background In endemic areas, placental malaria due to Plasmodium falciparum is most frequent and severe in first-time mothers, and increases the risk of infant mortality in their offspring. Placental malaria may increase the susceptibility of infants to malaria parasitemia, but evidence for this effect is inconclusive. Methods and Findings During 2002–2004, we monitored parasitemia in 453 infants, including 69 who were born to mothers with placental malaria, in a region of northeastern Tanzania where malaria transmission is intense. We used a Cox proportional hazards model to evaluate the time from birth to first parasitemia, and a generalized estimating equations logistic regression model to evaluate risk of any parasitemia throughout the first year of life. Compared with infants whose mothers did not have placental malaria at delivery (“PM-negative”), offspring of mothers with placental malaria at delivery (“PM-positive”) were 41% more likely to experience their first parasitemia at a younger age (adjusted hazard ratio [AHR] = 1.41, 95% confidence interval [CI] 1.01–1.99). The odds of parasitemia throughout infancy were strongly modified by the interaction between placental malaria and gravidity (p for interaction = 0.008, Type 3 likelihood ratio test). Offspring of PM-negative primigravidae had lower odds of parasitemia during infancy (adjusted odds ratio [AOR] = 0.67, 95% CI 0.50–0.91) than offspring of PM-negative multigravidae, and offspring of PM-positive primigravidae had the lowest odds (AOR = 0.21, 95% CI 0.09–0.47). In contrast, offspring of PM-positive multigravidae had significantly higher odds of parasitemia (AOR = 1.59, 95% CI 1.16–2.17). Conclusion Although parasitemia is more frequent in primigravid than multigravid women, the converse is true in their offspring, especially in offspring of PM-positive women. While placental malaria is known to increase mortality risk for first-born infants, it surprisingly reduced their risk of

Maternal malaria and gravidity interact to modify infant susceptibility to malaria.

PubMed

Mutabingwa, Theonest K; Bolla, Melissa C; Li, Jin-Long; Domingo, Gonzalo J; Li, Xiaohong; Fried, Michal; Duffy, Patrick E

2005-12-01

In endemic areas, placental malaria due to Plasmodium falciparum is most frequent and severe in first-time mothers, and increases the risk of infant mortality in their offspring. Placental malaria may increase the susceptibility of infants to malaria parasitemia, but evidence for this effect is inconclusive. During 2002-2004, we monitored parasitemia in 453 infants, including 69 who were born to mothers with placental malaria, in a region of northeastern Tanzania where malaria transmission is intense. We used a Cox proportional hazards model to evaluate the time from birth to first parasitemia, and a generalized estimating equations logistic regression model to evaluate risk of any parasitemia throughout the first year of life. Compared with infants whose mothers did not have placental malaria at delivery ("PM-negative"), offspring of mothers with placental malaria at delivery ("PM-positive") were 41% more likely to experience their first parasitemia at a younger age (adjusted hazard ratio [AHR] = 1.41, 95% confidence interval [CI] 1.01-1.99). The odds of parasitemia throughout infancy were strongly modified by the interaction between placental malaria and gravidity (p for interaction = 0.008, Type 3 likelihood ratio test). Offspring of PM-negative primigravidae had lower odds of parasitemia during infancy (adjusted odds ratio [AOR] = 0.67, 95% CI 0.50-0.91) than offspring of PM-negative multigravidae, and offspring of PM-positive primigravidae had the lowest odds (AOR = 0.21, 95% CI 0.09-0.47). In contrast, offspring of PM-positive multigravidae had significantly higher odds of parasitemia (AOR = 1.59, 95% CI 1.16-2.17). Although parasitemia is more frequent in primigravid than multigravid women, the converse is true in their offspring, especially in offspring of PM-positive women. While placental malaria is known to increase mortality risk for first-born infants, it surprisingly reduced their risk of parasitemia in this study. Placental malaria of multigravidae

Why is malaria associated with poverty? Findings from a cohort study in rural Uganda.

PubMed

Tusting, Lucy S; Rek, John; Arinaitwe, Emmanuel; Staedke, Sarah G; Kamya, Moses R; Cano, Jorge; Bottomley, Christian; Johnston, Deborah; Dorsey, Grant; Lindsay, Steve W; Lines, Jo

2016-08-04

Malaria control and sustainable development are linked, but implementation of 'multisectoral' intervention is restricted by a limited understanding of the causal pathways between poverty and malaria. We investigated the relationships between socioeconomic position (SEP), potential determinants of SEP, and malaria in Nagongera, rural Uganda. Socioeconomic information was collected for 318 children aged six months to 10 years living in 100 households, who were followed for up to 36 months. Mosquito density was recorded using monthly light trap collections. Parasite prevalence was measured routinely every three months and malaria incidence determined by passive case detection. First, we evaluated the association between success in smallholder agriculture (the primary livelihood source) and SEP. Second, we explored socioeconomic risk factors for human biting rate (HBR), parasite prevalence and incidence of clinical malaria, and spatial clustering of socioeconomic variables. Third, we investigated the role of selected factors in mediating the association between SEP and malaria. Relative agricultural success was associated with higher SEP. In turn, high SEP was associated with lower HBR (highest versus lowest wealth index tertile: Incidence Rate Ratio 0.71, 95 % confidence intervals (CI) 0.54-0.93, P = 0.01) and lower odds of malaria infection in children (highest versus lowest wealth index tertile: adjusted Odds Ratio 0.52, 95 % CI 0.35-0.78, P = 0.001), but SEP was not associated with clinical malaria incidence. Mediation analysis suggested that part of the total effect of SEP on malaria infection risk was explained by house type (24.9 %, 95 % CI 15.8-58.6 %) and food security (18.6 %, 95 % CI 11.6-48.3 %); however, the assumptions of the mediation analysis may not have been fully met. Housing improvements and agricultural development interventions to reduce poverty merit further investigation as multisectoral interventions against malaria. Further

Malaria Pathogenesis

NASA Astrophysics Data System (ADS)

Miller, Louis H.; Good, Michael F.; Milon, Genevieve

1994-06-01

Malaria is a disease caused by repeated cycles of growth of the parasite Plasmodium in the erythrocyte. Various cellular and molecular strategies allow the parasite to evade the human immune response for many cycles of parasite multiplication. Under certain circumstances Plasmodium infection causes severe anemia or cerebral malaria; the expression of disease is influenced by both parasite and host factors, as exemplified by the exacerbation of disease during pregnancy. This article provides an overview of malaria pathogenesis, synthesizing the recent field, laboratory, and epidemiological data that will lead to the development of strategies to reduce mortality and morbidity.