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Sample records for ranking malaria risk

  1. Ranking Malaria Risk Factors to Guide Malaria Control Efforts in African Highlands

    PubMed Central

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

    2009-01-01

    Introduction 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. Methods and Findings 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. Conclusions 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. PMID:19946627

  2. Ranking of elimination feasibility between malaria-endemic countries

    PubMed Central

    Tatem, Andrew J; Smith, David L; Gething, Peter W; Kabaria, Caroline W; Snow, Robert W; Hay, Simon I

    2010-01-01

    Summary Experience gained from the Global Malaria Eradication Program (1955–72) identified a set of shared technical and operational factors that enabled some countries to successfully eliminate malaria. Spatial data for these factors were assembled for all malaria-endemic countries and combined to provide an objective, relative ranking of countries by technical, operational, and combined elimination feasibility. The analysis was done separately for Plasmodium falciparum and Plasmodium vivax, and the limitations of the approach were discussed. The relative rankings suggested that malaria elimination would be most feasible in countries in the Americas and Asia, and least feasible in countries in central and west Africa. The results differed when feasibility was measured by technical or operational factors, highlighting the different types of challenge faced by each country. The results are not intended to be prescriptive, predictive, or to provide absolute assessments of feasibility, but they do show that spatial information is available to facilitate evidence-based assessments of the relative feasibility of malaria elimination by country that can be rapidly updated. PMID:21035838

  3. Issue Management Risk Ranking Systems

    SciTech Connect

    Novack, Steven David; Marshall, Frances Mc Clellan; Stromberg, Howard Merion; Grant, Gary Michael

    1999-06-01

    Thousands of safety issues have been collected on-line at the Idaho National Engineering and Environmental Laboratory (INEEL) as part of the Issue Management Plan. However, there has been no established approach to prioritize collected and future issues. The authors developed a methodology, based on hazards assessment, to identify and risk rank over 5000 safety issues collected at INEEL. This approach required that it was easily applied and understandable for site adaptation and commensurate with the Integrated Safety Plan. High-risk issues were investigated and mitigative/preventive measures were suggested and ranked based on a cost-benefit scheme to provide risk-informed safety measures. This methodology was consistent with other integrated safety management goals and tasks providing a site-wide risk informed decision tool to reduce hazardous conditions and focus resources on high-risk safety issues. As part of the issue management plan, this methodology was incorporated at the issue collection level and training was provided to management to better familiarize decision-makers with concepts of safety and risk. This prioritization methodology and issue dissemination procedure will be discussed. Results of issue prioritization and training efforts will be summarized. Difficulties and advantages of the process will be reported. Development and incorporation of this process into INEELs lessons learned reporting and the site-wide integrated safety management program will be shown with an emphasis on establishing self reliance and ownership of safety issues.

  4. Issue Management Risk Ranking Systems

    SciTech Connect

    F. M. Marshall; G. M. Grant; H. M. Stromberg; S. D. Novack

    1999-06-01

    Thousands of safety issues have been collected on-line at the Idaho National Engineering and Environmental Laboratory (INEEL) as part of the Issue Management Plan. However, there has been no established approach to prioritize collected and future issues. The authors developed a methodology, based on hazards assessment, to identify and risk rank over 5000 safety issues collected at INEEL. This approach required that it was easily applied and understandable for site adaptation and commensurate with the Integrated Safety Plan. High-risk issues were investigated and mitigative/preventive measures were suggested and ranked based on a cost-benefit scheme to provide risk-informed safety measures. This methodology was consistent with other integrated safety management goals and tasks providing a site-wide risk-informed decision tool to reduce hazardous conditions and focus resources on high-risk safety issues. As part of the issue management plan, this methodology was incorporated at the issue collection level and training was provided to management to better familiarize decision-makers with concepts of safety and risk. This prioritization methodology and issue dissemination procedure will be discussed. Results of issue prioritization and training efforts will be summarized. Difficulties and advantages of the process will be reported. Development and incorporation of this process into INEEL's lessons learned reporting and the site-wide integrated safety management program will be shown with an emphasis on establishing self reliance and ownership of safety issues.

  5. Augmenting the Deliberative Method for Ranking Risks.

    PubMed

    Susel, Irving; Lasley, Trace; Montezemolo, Mark; Piper, Joel

    2016-01-01

    The Department of Homeland Security (DHS) characterized and prioritized the physical cross-border threats and hazards to the nation stemming from terrorism, market-driven illicit flows of people and goods (illegal immigration, narcotics, funds, counterfeits, and weaponry), and other nonmarket concerns (movement of diseases, pests, and invasive species). These threats and hazards pose a wide diversity of consequences with very different combinations of magnitudes and likelihoods, making it very challenging to prioritize them. This article presents the approach that was used at DHS to arrive at a consensus regarding the threats and hazards that stand out from the rest based on the overall risk they pose. Due to time constraints for the decision analysis, it was not feasible to apply multiattribute methodologies like multiattribute utility theory or the analytic hierarchy process. Using a holistic approach was considered, such as the deliberative method for ranking risks first published in this journal. However, an ordinal ranking alone does not indicate relative or absolute magnitude differences among the risks. Therefore, the use of the deliberative method for ranking risks is not sufficient for deciding whether there is a material difference between the top-ranked and bottom-ranked risks, let alone deciding what the stand-out risks are. To address this limitation of ordinal rankings, the deliberative method for ranking risks was augmented by adding an additional step to transform the ordinal ranking into a ratio scale ranking. This additional step enabled the selection of stand-out risks to help prioritize further analysis.

  6. A global assessment of closed forests, deforestation and malaria risk.

    PubMed

    Guerra, C A; Snow, R W; Hay, S I

    2006-04-01

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

  7. A global assessment of closed forests, deforestation and malaria risk

    PubMed Central

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

    2011-01-01

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

  8. 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 ...

  9. Malaria Risk Areas in Thailand Border.

    PubMed

    Kaewpitoon, Natthawut; Loyd, Ryan A; Kaewpitoon, Soraya J; Rujirakul, Ratana

    2015-05-01

    Malaria is a serious public health problem of the world especially in Africa and Asia where the areas are located in the tropical and subtropical regions. Malaria is a mosquito-borne infectious disease ofhumans caused by parasitic protozoans of the genus Plasmodium. The present study aims to analyze the risk areas by using Potential Surface Analysis (PSA) with Geographic Information Systems (GIS) in Thai-Cambodia border including Buriram and Surin provinces. The study divided the factors into six factors including population density, land used (agriculture, houses, water reservoirs, forest), anopheles adult density in villages with reported cases, average annual rainfall, average annual temperature, average annual relative humidity and analyzing risk areas by analysis of PSA. 846 malaria cases were reported between 2008 and 2012, 80.50% and 19.50% from to the Surin and Buriram provinces, respectively. The most cases were found in females, in the 31-40-year age group and agricultural people. The predominant cases were Plasmodium vivax with 45.36%. The high-risk areas of malaria cases was on the 3,014.79 kilometer Thai-Cambodian border consisting offour districts: Nangrong and Nondaeng districts of Buriram province and Sangka and Buached districts of Surin province. The relationship between malaria morbidity with environmental factors found that malaria morbidity rates were associated with land use (forest areas), population density, anopheles adult density of statistical significance and influenced morbidity rates by 12.3% (Adjusted R2 = 0.261), 17.0 (Adjusted R2 = 0.170), and 11.1 (Adjusted R2 = 0.111). The climate factor associated to malaria morbidity with average annual relative humidity by percentage of 5.7 (Adjusted R2 = 0.057). This study showed that malaria is still a problem in Thailand-Cambodia border and the analysis of PSA with GIS can be used to assess the risk of malarial morbidity, and lead to planning, control, and prevention of the morbidity.

  10. A scale for ranking volcanoes by risk

    NASA Astrophysics Data System (ADS)

    Scandone, Roberto; Bartolini, Stefania; Martí, Joan

    2016-01-01

    We propose a simple volcanic risk coefficient (VRC) useful for comparing the degree of risk arising from different volcanoes, which may be used by civil protection agencies and volcano observatories to rapidly allocate limited resources even without a detailed knowledge of each volcano. Volcanic risk coefficient is given by the sum of the volcanic explosivity index (VEI) of the maximum expected eruption from the volcano, the logarithm of the eruption rate, and the logarithm of the population that may be affected by the maximum expected eruption. We show how to apply the method to rank the risk using as examples the volcanoes of Italy and in the Canary Islands. Moreover, we demonstrate that the maximum theoretical volcanic risk coefficient is 17 and pertains to the large caldera-forming volcanoes like Toba or Yellowstone that may affect the life of the entire planet. We develop also a simple plugin for a dedicated Quantum Geographic Information System (QGIS) software to graphically display the VRC of different volcanoes in a region.

  11. Malaria

    PubMed Central

    Suh, Kathryn N.; Kain, Kevin C.; Keystone, Jay S.

    2004-01-01

    Malaria is a parasitic infection of global importance. Although relatively uncommon in developed countries, where the disease occurs mainly in travellers who have returned from endemic regions, it remains one of the most prevalent infections of humans worldwide. In endemic regions, malaria is a significant cause of morbidity and mortality and creates enormous social and economic burdens. Current efforts to control malaria focus on reducing attributable morbidity and mortality. Targeted chemoprophylaxis and use of insecticide-treated bed nets have been successful in some endemic areas. For travellers to malaria-endemic regions, personal protective measures and appropriate chemoprophylaxis can significantly reduce the risk of infection. Prompt evaluation of the febrile traveller, a high degree of suspicion of malaria, rapid and accurate diagnosis, and appropriate antimalarial therapy are essential in order to optimize clinical outcomes of infected patients. Additional approaches to malaria control, including genetic manipulation of mosquitoes and malaria vaccines, are areas of ongoing research. PMID:15159369

  12. Risk factors for malaria in UK travellers.

    PubMed

    Moore, David A; Grant, Alison D; Armstrong, Margaret; Stümpfle, Richard; Behrens, Ron H

    2004-01-01

    After observing an apparent increase in severe falciparum malaria among travellers returning from The Gambia to the United Kingdom (UK) in the last quarter of 2000, we conducted a case-control study to investigate risk factors for malaria. The study participants had visited The Gambia between 1 September and 31 December 2000, travelling with the largest UK tour operator serving this destination. The main outcome measures were risk factors associated with malaria. Forty-six cases and 557 controls were studied. Eighty-seven percent of all participants reported antimalarial use (41% chloroquine/proguanil, 31% mefloquine). On univariate analysis the strongest risk factors for disease were: early calendar period of visit, longer duration of stay, non-use of antimalarial prophylaxis, non-use of mefloquine, lack of room air-conditioning, less use of insect repellent, prior visit to another malarial area and accommodation in 'hotel X'. After adjustment in multivariate analysis, use of mefloquine remained strongly protective (odds ratios, OR 0.13 [95% confidence intervals, 95% CI 0.04-0.40]), and the strongest independent risk factors for malaria were early calendar period (OR 5.19 [2.35-11.45] for 1 September to 9 November 2000 versus 10 November to 31 December 2000), prior visit to another malarial area (OR 3.27 [1.41-7.56]), main accommodation in 'hotel X' (OR 3.24 [1.51-6.97]) and duration of stay (OR 2.05 per extra week [1.42-2.95]). Neither any use, nor > 90% adherence to chloroquine/proguanil were protective (adjusted OR for any use 0.57 [0.27-1.21], P = 0.14). We concluded mefloquine use was strongly protective against malaria (87% protective efficacy), whereas chloroquine/proguanil, which is no longer recommended but remains widely used, was less than half as effective (43% protective efficacy). Waning efficacy of chloroquine/proguanil may have contributed to the observed increase in malaria among travellers to The Gambia in 2000. Local factors may also influence

  13. GIS-based prediction of malaria risk in Egypt.

    PubMed

    Hassan, A N; Kenawy, M A; Kamal, H; Abdel Sattar, A A; Sowilem, M M

    2003-07-01

    Environmental variables in a malaria geographic information system (GIS) database were analysed to discriminate between governorates at high and low risk of malaria. Only Fayoum governorate was categorized as a high risk area for malaria during the last 2 decades. Discriminant models correctly classified 96.3% of the risk categories and indicated that the most important predictor of risk is hydrogeology. Further GIS spatial analysis indicated that the high malaria risk in Fayoum is associated with a unique environmental envelope of biotic (presence of both efficient malaria vectors) and abiotic (hydrogeology and soil) variables. Recommendations for surveillance and control are discussed.

  14. 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 ...

  15. Iran Mortality and Measures of Risk: Rankings for Public policy

    PubMed Central

    Aalabaf-Sabaghi, M

    2010-01-01

    Background: This paper offers mortality risk rankings for Iranian mortality data. It extends methods to include mixed cohorts, tests changes in mortality risks, compares measures of risk and discusses public policy implications. Methods: The methodology used in risk measures takes current practice and extends it to include variations in population dynamics. The specification is presented and compared with existing literature. Results: Our findings confirm literature results in the re-ordering that takes place when different risk measures are used. In addition, we find there is consistency in risk rankings between 1999 and 2000 records of Iranian mortality data. Thus, these risk measures are stable, robust across time and relay risk information consistently. Conclusions: There are considerable implications in adopting particular risk measures for public policy. However, given properties of risk measures discussed here, it is clear that policy makers can select relevant risk measures depending on their priorities. PMID:23112989

  16. Malaria risk in Nigeria: Bayesian geostatistical modelling of 2010 malaria indicator survey data.

    PubMed

    Adigun, Abbas B; Gajere, Efron N; Oresanya, Olusola; Vounatsou, Penelope

    2015-04-14

    In 2010, the National Malaria Control Programme with the support of Roll Back Malaria partners implemented a nationally representative Malaria Indicator Survey (MIS), which assembled malaria burden and control intervention related data. The MIS data were analysed to produce a contemporary smooth map of malaria risk and evaluate the control interventions effects on parasitaemia risk after controlling for environmental/climatic, demographic and socioeconomic characteristics. A Bayesian geostatistical logistic regression model was fitted on the observed parasitological prevalence data. Important environmental/climatic risk factors of parasitaemia were identified by applying Bayesian variable selection within geostatistical model. The best model was employed to predict the disease risk over a grid of 4 km(2) resolution. Validation was carried out to assess model predictive performance. Various measures of control intervention coverage were derived to estimate the effects of interventions on parasitaemia risk after adjusting for environmental, socioeconomic and demographic factors. Normalized difference vegetation index and rainfall were identified as important environmental/climatic predictors of malaria risk. The population adjusted risk estimates ranges from 6.46% in Lagos state to 43.33% in Borno. Interventions appear to not have important effect on malaria risk. The odds of parasitaemia appears to be on downward trend with improved socioeconomic status and living in rural areas increases the odds of testing positive to malaria parasites. Older children also have elevated risk of malaria infection. The produced maps and estimates of parasitaemic children give an important synoptic view of current parasite prevalence in the country. Control activities will find it a useful tool in identifying priority areas for intervention.

  17. Malaria in pregnancy: diagnosing infection and identifying fetal risk.

    PubMed

    Conroy, Andrea L; McDonald, Chloe R; Kain, Kevin C

    2012-11-01

    Despite increased malaria control efforts, recent reports indicate that over 1.2 million deaths due to malaria occurred in 2010. Pregnant women represent a particularly vulnerable risk group as malaria infection can lead to life-threatening disease for the mother and fetus. With 125 million women at risk of malaria in pregnancy every year, better diagnostic tools are needed for timely identification and treatment of malaria infection. Diagnostic surveillance tools are also needed to estimate disease burden and inform public health policies. In this review, the authors focus on malaria diagnostics in pregnancy and discuss considerations for different Plasmodium species and geographic regions. The authors also look at promising diagnostic modalities to monitor fetal and maternal health in pregnancy and discuss implementation barriers for low resource settings.

  18. GIS and Remote Sensing for Malaria Risk Mapping, Ethiopia

    NASA Astrophysics Data System (ADS)

    Ahmed, A.

    2014-11-01

    Integrating malaria data into a decision support system (DSS) using Geographic Information System (GIS) and remote sensing tool can provide timely information and decision makers get prepared to make better and faster decisions which can reduce the damage and minimize the loss caused. This paper attempted to asses and produce maps of malaria prone areas including the most important natural factors. The input data were based on the geospatial factors including climatic, social and Topographic aspects from secondary data. The objective of study is to prepare malaria hazard, Vulnerability, and element at risk map which give the final output, malaria risk map. The malaria hazard analyses were computed using multi criteria evaluation (MCE) using environmental factors such as topographic factors (elevation, slope and flow distance to stream), land use/ land cover and Breeding site were developed and weighted, then weighted overlay technique were computed in ArcGIS software to generate malaria hazard map. The resulting malaria hazard map depicts that 19.2 %, 30.8 %, 25.1 %, 16.6 % and 8.3 % of the District were subjected to very high, high, moderate, low and very low malaria hazard areas respectively. For vulnerability analysis, health station location and speed constant in Spatial Analyst module were used to generate factor maps. For element at risk, land use land cover map were used to generate element at risk map. Finally malaria risk map of the District was generated. Land use land cover map which is the element at risk in the District, the vulnerability map and the hazard map were overlaid. The final output based on this approach is a malaria risk map, which is classified into 5 classes which is Very High-risk area, High-risk area, Moderate risk area, Low risk area and Very low risk area. The risk map produced from the overlay analysis showed that 20.5 %, 11.6 %, 23.8 %, 34.1 % and 26.4 % of the District were subjected to very high, high, moderate, low and very low

  19. Towards malaria risk prediction in Afghanistan using remote sensing

    PubMed Central

    2010-01-01

    Background Malaria is a significant public health concern in Afghanistan. Currently, approximately 60% of the population, or nearly 14 million people, live in a malaria-endemic area. Afghanistan's diverse landscape and terrain contributes to the heterogeneous malaria prevalence across the country. Understanding the role of environmental variables on malaria transmission can further the effort for malaria control programme. Methods Provincial malaria epidemiological data (2004-2007) collected by the health posts in 23 provinces were used in conjunction with space-borne observations from NASA satellites. Specifically, the environmental variables, including precipitation, temperature and vegetation index measured by the Tropical Rainfall Measuring Mission and the Moderate Resolution Imaging Spectoradiometer, were used. Regression techniques were employed to model malaria cases as a function of environmental predictors. The resulting model was used for predicting malaria risks in Afghanistan. The entire time series except the last 6 months is used for training, and the last 6-month data is used for prediction and validation. Results Vegetation index, in general, is the strongest predictor, reflecting the fact that irrigation is the main factor that promotes malaria transmission in Afghanistan. Surface temperature is the second strongest predictor. Precipitation is not shown as a significant predictor, as it may not directly lead to higher larval population. Autoregressiveness of the malaria epidemiological data is apparent from the analysis. The malaria time series are modelled well, with provincial average R2 of 0.845. Although the R2 for prediction has larger variation, the total 6-month cases prediction is only 8.9% higher than the actual cases. Conclusions The provincial monthly malaria cases can be modelled and predicted using satellite-measured environmental parameters with reasonable accuracy. The Third Strategic Approach of the WHO EMRO Malaria Control and

  20. Towards malaria risk prediction in Afghanistan using remote sensing.

    PubMed

    Adimi, Farida; Soebiyanto, Radina P; Safi, Najibullah; Kiang, Richard

    2010-05-13

    Malaria is a significant public health concern in Afghanistan. Currently, approximately 60% of the population, or nearly 14 million people, live in a malaria-endemic area. Afghanistan's diverse landscape and terrain contributes to the heterogeneous malaria prevalence across the country. Understanding the role of environmental variables on malaria transmission can further the effort for malaria control programme. Provincial malaria epidemiological data (2004-2007) collected by the health posts in 23 provinces were used in conjunction with space-borne observations from NASA satellites. Specifically, the environmental variables, including precipitation, temperature and vegetation index measured by the Tropical Rainfall Measuring Mission and the Moderate Resolution Imaging Spectoradiometer, were used. Regression techniques were employed to model malaria cases as a function of environmental predictors. The resulting model was used for predicting malaria risks in Afghanistan. The entire time series except the last 6 months is used for training, and the last 6-month data is used for prediction and validation. Vegetation index, in general, is the strongest predictor, reflecting the fact that irrigation is the main factor that promotes malaria transmission in Afghanistan. Surface temperature is the second strongest predictor. Precipitation is not shown as a significant predictor, as it may not directly lead to higher larval population. Autoregressiveness of the malaria epidemiological data is apparent from the analysis. The malaria time series are modelled well, with provincial average R2 of 0.845. Although the R2 for prediction has larger variation, the total 6-month cases prediction is only 8.9% higher than the actual cases. The provincial monthly malaria cases can be modelled and predicted using satellite-measured environmental parameters with reasonable accuracy. The Third Strategic Approach of the WHO EMRO Malaria Control and Elimination Plan is aimed to develop a cost

  1. Remote sensing and malaria risk for military personnel in Africa.

    PubMed

    Machault, Vanessa; Orlandi-Pradines, Eve; Michel, Rémy; Pagès, Frédéric; Texier, Gaëtan; Pradines, Bruno; Fusaï, Thierry; Boutin, Jean-Paul; Rogier, Christophe

    2008-01-01

    Nonimmune travelers in malaria-endemic areas are exposed to transmission and may experience clinical malaria attacks during or after their travel despite using antivectorial devices or chemoprophylaxis. Environment plays an essential role in the epidemiology of this disease. Remote-sensed environmental information had not yet been tested as an indicator of malaria risk among nonimmune travelers. A total of 1,189 personnel from 10 French military companies traveling for a short-duration mission (about 4 mo) in sub-Saharan Africa from February 2004 to February 2006 were enrolled in a prospective longitudinal cohort study. Incidence rate of clinical malaria attacks occurring during or after the mission was analyzed according to individual characteristics, compliance with antimalaria prophylactic measures, and environmental information obtained from earth observation satellites for all the locations visited during the missions. Age, the lack of compliance with the chemoprophylaxis, and staying in areas with an average Normalized Difference Vegetation Index higher than 0.35 were risk factors for clinical malaria. Remotely sensed environmental data can provide important planning information on the likely level of malaria risk among nonimmune travelers who could be briefly exposed to malaria transmission and could be used to standardize for the risk of malaria transmission when evaluating the efficacy of antimalaria prophylactic measures.

  2. A ranking of European veterinary medicines based on environmental risks.

    PubMed

    Kools, Stefan A E; Boxall, Alistair; Moltmann, Johann F; Bryning, Gareth; Koschorreck, Jan; Knacker, Thomas

    2008-10-01

    The most likely entry pathways of veterinary pharmaceuticals to the environment are via slurry or manure from intensively reared animals to soil and via dung or urine from animals grazing on pasture. These pathways may result in contamination of surface water via runoff or leaching and drainage. Direct entry into water may occur by defecation by pasture animals or by Scompanion animals. In addition, application of medicines for aquaculture is important for a limited number of veterinary medicinal products. For a large number of veterinary medicinal products, consistent data on the environmental risk have never been generated. In this project, a simple risk-based ranking procedure was developed that should allow assessing the potential for environmental risks of active substances of veterinary medicinal products. In the European Union approximately 2000 products containing 741 active substances were identified. In the prescreening step and in agreement with the technical guidelines released by the European Medicines Agency, 294 natural substances, complex mixtures, and substances with low expected exposure were exempted from the ranking procedure. For 233 active substances, sufficient information was collated on 4 exposure scenarios: Intensively reared animals, pasture animals, companion animals, and aquaculture. The ranking approach was performed in 4 phases: (1) usage estimation; (2) characterization of exposure to soil, dung, surface water, and aquatic organisms depending on exposure scenarios; (3) characterization of effects based on therapeutical doses; and (4) risk characterization, which is the ratio of exposure to effects (risk index), and ranking. Generally, the top-ranked substances were from the antibiotic and parasiticide groups of veterinary medicines. Differences occurred in the ranking of substances in soil via application to either intensively reared or pasture animals. In intensive rearing, anticoccidia, for example, are used as feed

  3. DebtRank-transparency: Controlling systemic risk in financial networks

    PubMed Central

    Thurner, Stefan; Poledna, Sebastian

    2013-01-01

    Nodes in a financial network, such as banks, cannot assess the true risks associated with lending to other nodes in the network, unless they have full information on the riskiness of all other nodes. These risks can be estimated by using network metrics (as DebtRank) of the interbank liability network. With a simple agent based model we show that systemic risk in financial networks can be drastically reduced by increasing transparency, i.e. making the DebtRank of individual banks visible to others, and by imposing a rule, that reduces interbank borrowing from systemically risky nodes. This scheme does not reduce the efficiency of the financial network, but fosters a more homogeneous risk-distribution within the system in a self-organized critical way. The reduction of systemic risk is due to a massive reduction of cascading failures in the transparent system. A regulation-policy implementation of the proposed scheme is discussed. PMID:23712454

  4. Predicting Disease Risk Using Bootstrap Ranking and Classification Algorithms

    PubMed Central

    Manor, Ohad; Segal, Eran

    2013-01-01

    Genome-wide association studies (GWAS) are widely used to search for genetic loci that underlie human disease. Another goal is to predict disease risk for different individuals given their genetic sequence. Such predictions could either be used as a “black box” in order to promote changes in life-style and screening for early diagnosis, or as a model that can be studied to better understand the mechanism of the disease. Current methods for risk prediction typically rank single nucleotide polymorphisms (SNPs) by the p-value of their association with the disease, and use the top-associated SNPs as input to a classification algorithm. However, the predictive power of such methods is relatively poor. To improve the predictive power, we devised BootRank, which uses bootstrapping in order to obtain a robust prioritization of SNPs for use in predictive models. We show that BootRank improves the ability to predict disease risk of unseen individuals in the Wellcome Trust Case Control Consortium (WTCCC) data and results in a more robust set of SNPs and a larger number of enriched pathways being associated with the different diseases. Finally, we show that combining BootRank with seven different classification algorithms improves performance compared to previous studies that used the WTCCC data. Notably, diseases for which BootRank results in the largest improvements were recently shown to have more heritability than previously thought, likely due to contributions from variants with low minimum allele frequency (MAF), suggesting that BootRank can be beneficial in cases where SNPs affecting the disease are poorly tagged or have low MAF. Overall, our results show that improving disease risk prediction from genotypic information may be a tangible goal, with potential implications for personalized disease screening and treatment. PMID:23990773

  5. Predicting disease risk using bootstrap ranking and classification algorithms.

    PubMed

    Manor, Ohad; Segal, Eran

    2013-01-01

    Genome-wide association studies (GWAS) are widely used to search for genetic loci that underlie human disease. Another goal is to predict disease risk for different individuals given their genetic sequence. Such predictions could either be used as a "black box" in order to promote changes in life-style and screening for early diagnosis, or as a model that can be studied to better understand the mechanism of the disease. Current methods for risk prediction typically rank single nucleotide polymorphisms (SNPs) by the p-value of their association with the disease, and use the top-associated SNPs as input to a classification algorithm. However, the predictive power of such methods is relatively poor. To improve the predictive power, we devised BootRank, which uses bootstrapping in order to obtain a robust prioritization of SNPs for use in predictive models. We show that BootRank improves the ability to predict disease risk of unseen individuals in the Wellcome Trust Case Control Consortium (WTCCC) data and results in a more robust set of SNPs and a larger number of enriched pathways being associated with the different diseases. Finally, we show that combining BootRank with seven different classification algorithms improves performance compared to previous studies that used the WTCCC data. Notably, diseases for which BootRank results in the largest improvements were recently shown to have more heritability than previously thought, likely due to contributions from variants with low minimum allele frequency (MAF), suggesting that BootRank can be beneficial in cases where SNPs affecting the disease are poorly tagged or have low MAF. Overall, our results show that improving disease risk prediction from genotypic information may be a tangible goal, with potential implications for personalized disease screening and treatment.

  6. Modeling the risk of malaria for travelers to areas with stable malaria transmission

    PubMed Central

    2009-01-01

    Background Malaria is an important threat to travelers visiting endemic regions. The risk of acquiring malaria is complex and a number of factors including transmission intensity, duration of exposure, season of the year and use of chemoprophylaxis have to be taken into account estimating risk. Materials and methods A mathematical model was developed to estimate the risk of non-immune individual acquiring falciparum malaria when traveling to the Amazon region of Brazil. The risk of malaria infection to travelers was calculated as a function of duration of exposure and season of arrival. Results The results suggest significant variation of risk for non-immune travelers depending on arrival season, duration of the visit and transmission intensity. The calculated risk for visitors staying longer than 4 months during peak transmission was 0.5% per visit. Conclusions Risk estimates based on mathematical modeling based on accurate data can be a valuable tool in assessing risk/benefits and cost/benefits when deciding on the value of interventions for travelers to malaria endemic regions. PMID:20015392

  7. Assessing introduction risk using species’ rank-abundance distributions

    PubMed Central

    Chan, Farrah T.; Bradie, Johanna; Briski, Elizabeta; Bailey, Sarah A.; Simard, Nathalie; MacIsaac, Hugh J.

    2015-01-01

    Mixed-species assemblages are often unintentionally introduced into new ecosystems. Analysing how assemblage structure varies during transport may provide insights into how introduction risk changes before propagules are released. Characterization of introduction risk is typically based on assessments of colonization pressure (CP, the number of species transported) and total propagule pressure (total PP, the total abundance of propagules released) associated with an invasion vector. Generally, invasion potential following introduction increases with greater CP or total PP. Here, we extend these assessments using rank-abundance distributions to examine how CP : total PP relationships change temporally in ballast water of ocean-going ships. Rank-abundance distributions and CP : total PP patterns varied widely between trans-Atlantic and trans-Pacific voyages, with the latter appearing to pose a much lower risk than the former. Responses also differed by taxonomic group, with invertebrates experiencing losses mainly in total PP, while diatoms and dinoflagellates sustained losses mainly in CP. In certain cases, open-ocean ballast water exchange appeared to increase introduction risk by uptake of new species or supplementation of existing ones. Our study demonstrates that rank-abundance distributions provide new insights into the utility of CP and PP in characterizing introduction risk. PMID:25473007

  8. Assessing introduction risk using species' rank-abundance distributions.

    PubMed

    Chan, Farrah T; Bradie, Johanna; Briski, Elizabeta; Bailey, Sarah A; Simard, Nathalie; MacIsaac, Hugh J

    2015-01-22

    Mixed-species assemblages are often unintentionally introduced into new ecosystems. Analysing how assemblage structure varies during transport may provide insights into how introduction risk changes before propagules are released. Characterization of introduction risk is typically based on assessments of colonization pressure (CP, the number of species transported) and total propagule pressure (total PP, the total abundance of propagules released) associated with an invasion vector. Generally, invasion potential following introduction increases with greater CP or total PP. Here, we extend these assessments using rank-abundance distributions to examine how CP : total PP relationships change temporally in ballast water of ocean-going ships. Rank-abundance distributions and CP : total PP patterns varied widely between trans-Atlantic and trans-Pacific voyages, with the latter appearing to pose a much lower risk than the former. Responses also differed by taxonomic group, with invertebrates experiencing losses mainly in total PP, while diatoms and dinoflagellates sustained losses mainly in CP. In certain cases, open-ocean ballast water exchange appeared to increase introduction risk by uptake of new species or supplementation of existing ones. Our study demonstrates that rank-abundance distributions provide new insights into the utility of CP and PP in characterizing introduction risk.

  9. Ranking the risks from multiple hazards in a small community.

    PubMed

    Li, Hua; Apostolakis, George E; Gifun, Joseph; VanSchalkwyk, William; Leite, Susan; Barber, David

    2009-03-01

    Natural hazards, human-induced accidents, and malicious acts have caused great losses and disruptions to society. After September 11, 2001, critical infrastructure protection has become a national focus in the United States and is likely to remain one for the foreseeable future. Damage to the infrastructures and assets could be mitigated through predisaster planning and actions. A systematic methodology was developed to assess and rank the risks from these multiple hazards in a community of 20,000 people. It is an interdisciplinary study that includes probabilistic risk assessment (PRA), decision analysis, and expert judgment. Scenarios are constructed to show how the initiating events evolve into undesirable consequences. A value tree, based on multi-attribute utility theory (MAUT), is used to capture the decisionmaker's preferences about the impacts on the infrastructures and other assets. The risks from random failures are ranked according to their expected performance index (PI), which is the product of frequency, probabilities, and consequences of a scenario. Risks from malicious acts are ranked according to their PI as the frequency of attack is not available. A deliberative process is used to capture the factors that could not be addressed in the analysis and to scrutinize the results. This methodology provides a framework for the development of a risk-informed decision strategy. Although this study uses the Massachusetts Institute of Technology campus as a case study of a real project, it is a general methodology that could be used by other similar communities and municipalities.

  10. Epidemiological risk stratification of malaria in the Americas.

    PubMed

    Castillo-Salgado, C

    1992-01-01

    During the last years, malaria had a significant increase in Latin America, emerging again as one critical health problem in the Region of the Americas. More than 1.04 million new cases were reported in 1990. This resurgence of malaria needed a comprehensive strategy for its prevention and control. National malaria control programs recognized the epidemiological stratification of malaria as a valuable method to assist them in the recognition of local variations and factors that specifically contribute to the level and intensity of transmission in critical malarious areas. Also it serves as a useful instrument for the selection of needed malaria prevention and control activities. The principal feature of this approach is to provide a dynamic and ongoing process for assessing the epidemiological importance of different risk factors (socio-economic, ecological, organization of health services) in malaria transmission. Health interventions are based on this assessment and are aimed directly at the reduction or elimination of the identified risk factors operating at the local level. Intersectorial co-participation and the integration of malaria programs in local health services are also important aspects of this public health approach.

  11. Potential impact of global climate change on malaria risk

    SciTech Connect

    Martens, W.J.M.; Rotmans, J. |; Niessen, L.W.; Jetten, T.H.; McMichael, A.J.

    1995-05-01

    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 to 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.

  12. Iron Status Predicts Malaria Risk in Malawian Preschool Children

    PubMed Central

    Jonker, Femkje A. M.; Calis, Job C. J.; van Hensbroek, Michael Boele; Phiri, Kamija; Geskus, Ronald B.; Brabin, Bernard J.; Leenstra, Tjalling

    2012-01-01

    Introduction Iron deficiency is highly prevalent in pre-school children in developing countries and an important health problem in sub-Saharan Africa. A debate exists on the possible protective effect of iron deficiency against malaria and other infections; yet consensus is lacking due to limited data. Recent studies have focused on the risks of iron supplementation but the effect of an individual's iron status on malaria risk remains unclear. Studies of iron status in areas with a high burden of infections often are exposed to bias. The aim of this study was to assess the predictive value of baseline iron status for malaria risk explicitly taking potential biases into account. Methods and materials We prospectively assessed the relationship between baseline iron deficiency (serum ferritin <30 µg/L) and malaria risk in a cohort of 727 Malawian preschool children during a year of follow-up. Data were analyzed using marginal structural Cox regression models and confounders were selected using causal graph theory. Sensitivity of results to bias resulting from misclassification of iron status by concurrent inflammation and to bias from unmeasured confounding were assessed using modern causal inference methods. Results and Conclusions The overall incidence of malaria parasitemia and clinical malaria was 1.9 (95% CI 1.8–2.0) and 0.7 (95% CI 0.6–0.8) events per person-year, respectively. Children with iron deficiency at baseline had a lower incidence of malaria parasitemia and clinical malaria during a year of follow-up; adjusted hazard ratio's 0.55 (95%-CI:0.41–0.74) and 0.49 (95%-CI:0.33–0.73), respectively. Our results suggest that iron deficiency protects against malaria parasitemia and clinical malaria in young children. Therefore the clinical importance of treating iron deficiency in a pre-school child should be weighed carefully against potential harms. In malaria endemic areas treatment of iron deficiency in children requires sustained prevention of

  13. Model stimulations to estimate malaria risk under climate change.

    PubMed

    Jetten, T H; Martens, W J; Takken, W

    1996-05-01

    The current geographic range of malaria is much smaller than its potential range. In many regions there exists a phenomena characterized as "Anophelism without malaria." The vectors are present but malaria transmission does not occur. Vectorial capacity often has been used as a parameter to estimate the susceptibility of an area to malaria. Model computations with global climatological data show that a dynamic concept of vectorial capacity can be used as a comparative risk indicator to predict the current extent and distribution of malarious regions in the world. A sensitivity analysis done in 3 distinct geographic areas shows that the areas of largest change of epidemic potential caused by a temperature increase are those where mosquitoes already occur but where development of the parasite is limited by temperature. Computations with the model presented here predict, with different climate scenarios, an increased malaria risk in areas bordering malaria endemic regions and at higher altitudes within malarious regions under a temperature increase of 2-4 degrees C.

  14. Malaria Risk Mapping for Control in the Republic of Sudan

    PubMed Central

    Noor, Abdisalan M.; ElMardi, Khalid A.; Abdelgader, Tarig M.; Patil, Anand P.; Amine, Ahmed A. A.; Bakhiet, Sahar; Mukhtar, Maowia M.; Snow, Robert W.

    2012-01-01

    Evidence shows that malaria risk maps are rarely tailored to address national control program ambitions. Here, we generate a malaria risk map adapted for malaria control in Sudan. Community Plasmodium falciparum parasite rate (PfPR) data from 2000 to 2010 were assembled and were standardized to 2–10 years of age (PfPR2–10). Space-time Bayesian geostatistical methods were used to generate a map of malaria risk for 2010. Surfaces of aridity, urbanization, irrigation schemes, and refugee camps were combined with the PfPR2–10 map to tailor the epidemiological stratification for appropriate intervention design. In 2010, a majority of the geographical area of the Sudan had risk of < 1% PfPR2–10. Areas of meso- and hyperendemic risk were located in the south. About 80% of Sudan's population in 2011 was in the areas in the desert, urban centers, or where risk was < 1% PfPR2–10. Aggregated data suggest reducing risks in some high transmission areas since the 1960s. PMID:23033400

  15. Mapping malaria risk and vulnerability in the United Republic of Tanzania: a spatial explicit model.

    PubMed

    Hagenlocher, Michael; Castro, Marcia C

    2015-01-01

    Outbreaks of vector-borne diseases (VBDs) impose a heavy burden on vulnerable populations. Despite recent progress in eradication and control, malaria remains the most prevalent VBD. Integrative approaches that take into account environmental, socioeconomic, demographic, biological, cultural, and political factors contributing to malaria risk and vulnerability are needed to effectively reduce malaria burden. Although the focus on malaria risk has increasingly gained ground, little emphasis has been given to develop quantitative methods for assessing malaria risk including malaria vulnerability in a spatial explicit manner. Building on a conceptual risk and vulnerability framework, we propose a spatial explicit approach for modeling relative levels of malaria risk - as a function of hazard, exposure, and vulnerability - in the United Republic of Tanzania. A logistic regression model was employed to identify a final set of risk factors and their contribution to malaria endemicity based on multidisciplinary geospatial information. We utilized a Geographic Information System for the construction and visualization of a malaria vulnerability index and its integration into a spatially explicit malaria risk map. The spatial pattern of malaria risk was very heterogeneous across the country. Malaria risk was higher in Mainland areas than in Zanzibar, which is a result of differences in both malaria entomological inoculation rate and prevailing vulnerabilities. Areas of high malaria risk were identified in the southeastern part of the country, as well as in two distinct "hotspots" in the northwestern part of the country bordering Lake Victoria, while concentrations of high malaria vulnerability seem to occur in the northwestern, western, and southeastern parts of the mainland. Results were visualized using both 10×10 km(2) grids and subnational administrative units. The presented approach makes an important contribution toward a decision support tool. By decomposing malaria

  16. Using Structured Additive Regression Models to Estimate Risk Factors of Malaria: Analysis of 2010 Malawi Malaria Indicator Survey Data

    PubMed Central

    Chirombo, James; Lowe, Rachel; Kazembe, Lawrence

    2014-01-01

    Background After years of implementing Roll Back Malaria (RBM) interventions, the changing landscape of malaria in terms of risk factors and spatial pattern has not been fully investigated. This paper uses the 2010 malaria indicator survey data to investigate if known malaria risk factors remain relevant after many years of interventions. Methods We adopted a structured additive logistic regression model that allowed for spatial correlation, to more realistically estimate malaria risk factors. Our model included child and household level covariates, as well as climatic and environmental factors. Continuous variables were modelled by assuming second order random walk priors, while spatial correlation was specified as a Markov random field prior, with fixed effects assigned diffuse priors. Inference was fully Bayesian resulting in an under five malaria risk map for Malawi. Results Malaria risk increased with increasing age of the child. With respect to socio-economic factors, the greater the household wealth, the lower the malaria prevalence. A general decline in malaria risk was observed as altitude increased. Minimum temperatures and average total rainfall in the three months preceding the survey did not show a strong association with disease risk. Conclusions The structured additive regression model offered a flexible extension to standard regression models by enabling simultaneous modelling of possible nonlinear effects of continuous covariates, spatial correlation and heterogeneity, while estimating usual fixed effects of categorical and continuous observed variables. Our results confirmed that malaria epidemiology is a complex interaction of biotic and abiotic factors, both at the individual, household and community level and that risk factors are still relevant many years after extensive implementation of RBM activities. PMID:24991915

  17. Malaria

    MedlinePlus

    ... common?Malaria is a health problem in many tropical and subtropical countries, including portions of Central and ... these countries. If you are traveling to a tropical area or to a country where malaria is ...

  18. 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…

  19. Malaria

    DTIC Science & Technology

    2011-06-01

    appearance of dark urine after an acute attack of falciparum malaria. Other complications include gastroenteritis in children, pulmonary edema, severe...placental malaria on mothers and neonates from Zaire. Z Parasitenkd 1986;72:57-64. 12. Kean BH, Smith JA. Death due to estivo-autumnal malaria: a

  20. 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…

  1. Ranking ecological risks of multiple chemical stressors on amphibians.

    PubMed

    Fedorenkova, Anastasia; Vonk, J Arie; Lenders, H J Rob; Creemers, Raymond C M; Breure, Anton M; Hendriks, A Jan

    2012-06-01

    Populations of amphibians have been declining worldwide since the late 1960s. Despite global concern, no studies have quantitatively assessed the major causes of this decline. In the present study, species sensitivity distributions (SSDs) were developed to analyze the sensitivity of anurans for ammonium, nitrate, heavy metals (cadmium, copper), pesticides (18 compounds), and acidification (pH) based on laboratory toxicity data. Ecological risk (ER) was calculated as the probability that a measured environmental concentration of a particular stressor in habitats where anurans were observed would exceed the toxic effect concentrations derived from the species sensitivity distributions. The assessment of ER was used to rank the stressors according to their potential risk to anurans based on a case study of Dutch freshwater bodies. The derived ERs revealed that threats to populations of anurans decreased in the sequence of pH, copper, diazinon, ammonium, and endosulfan. Other stressors studied were of minor importance. The method of deriving ER by combining field observation data and laboratory data provides insight into potential threats to species in their habitats and can be used to prioritize stressors, which is necessary to achieve effective management in amphibian conservation.

  2. Risk-ranking IST components into two categories

    SciTech Connect

    Rowley, C.W.

    1996-12-01

    The ASME has utilized several schemes for identifying the appropriate scope of components for inservice testing (IST). The initial scope was ASME Code Class 1/2/3, with all components treated equally. Later the ASME Operations and Maintenance (O&M) Committee decided to use safe shutdown and accident mitigation as the scoping criteria, but continued to treat all components equal inside that scope. Recently the ASME O&M Committee decided to recognize service condition of the component, hence the comprehensive pump test. Although probabilistic risk assessments (PRAs) are incredibly complex plant models and computer hardware and software intensive, they are a tool that can be utilized by many plant engineering organizations to analyze plant system and component applications. In 1992 the ASME O&M Committee got interested in using the PRA as a tool to categorize its pumps and valves. In 1994 the ASME O&M Committee commissioned the ASME Center for Research and Technology Development (CRTD) to develop a process that adapted the PRA technology to IST. In late 1995 that process was presented to the ASME O&M Committee. The process had three distinct portions: (1) risk-rank the IST components; (2) develop a more effective testing strategy for More Safety Significant Components; and (3) develop a more economic testing strategy for Less Safety Significant Components.

  3. Risk factors for malaria infection among rubber tappers living in a malaria control program area in southern Thailand.

    PubMed

    Pattanasin, Sarika; Satitvipawee, Pratana; Wongklang, Warunnee; Viwatwongkasem, Chukiat; Bhumiratana, Adisak; Soontornpipit, Pichitpong; Jareinpituk, Sutthi

    2012-11-01

    Rubber tappers work begins at midnight during the feeding time of Anopheles maculatus and An. minimus, two common malaria vectors in southern Thailand. We studied the association between rubber tapper behavior and malaria infections as reported to the Notified Disease Surveillance System during 2010 in Prachuab Khiri Khan Province, Thailand. In that province insecticide treated bednets are distributed free to the population and insecticide residual spraying is performed annually. A random sample of 394 rubber tapper households was interviewed from October 2010 to May 2011. Twenty-six households (6.6%) had at least one family member who contracted malaria during 2010. Poisson regression was used to identify potential characteristics associated with malaria. Multilevel Poisson regression was used to test for simultaneous effects of tapper behavior and household risk for malaria infection. The estimated incidence rate ratio (IRR) for contracting malaria among those owning a farming hut was 2.9 (95% CI 1.1-7.3, p < 0.05) after controlling for other variables. Even in areas where control programs are in place, malaria infection among rubber tappers is common. Given the Thai Government's plan to expand the rubber plantation areas to other regions of the country without specific prevention for this at-risk population, the malaria burden in Thailand may increase.

  4. Quantified Risk Ranking Model for Condition-Based Risk and Reliability Centered Maintenance

    NASA Astrophysics Data System (ADS)

    Chattopadhyaya, Pradip Kumar; Basu, Sushil Kumar; Majumdar, Manik Chandra

    2017-06-01

    In the recent past, risk and reliability centered maintenance (RRCM) framework is introduced with a shift in the methodological focus from reliability and probabilities (expected values) to reliability, uncertainty and risk. In this paper authors explain a novel methodology for risk quantification and ranking the critical items for prioritizing the maintenance actions on the basis of condition-based risk and reliability centered maintenance (CBRRCM). The critical items are identified through criticality analysis of RPN values of items of a system and the maintenance significant precipitating factors (MSPF) of items are evaluated. The criticality of risk is assessed using three risk coefficients. The likelihood risk coefficient treats the probability as a fuzzy number. The abstract risk coefficient deduces risk influenced by uncertainty, sensitivity besides other factors. The third risk coefficient is called hazardous risk coefficient, which is due to anticipated hazards which may occur in the future and the risk is deduced from criteria of consequences on safety, environment, maintenance and economic risks with corresponding cost for consequences. The characteristic values of all the three risk coefficients are obtained with a particular test. With few more tests on the system, the values may change significantly within controlling range of each coefficient, hence `random number simulation' is resorted to obtain one distinctive value for each coefficient. The risk coefficients are statistically added to obtain final risk coefficient of each critical item and then the final rankings of critical items are estimated. The prioritization in ranking of critical items using the developed mathematical model for risk assessment shall be useful in optimization of financial losses and timing of maintenance actions.

  5. Quantified Risk Ranking Model for Condition-Based Risk and Reliability Centered Maintenance

    NASA Astrophysics Data System (ADS)

    Chattopadhyaya, Pradip Kumar; Basu, Sushil Kumar; Majumdar, Manik Chandra

    2016-03-01

    In the recent past, risk and reliability centered maintenance (RRCM) framework is introduced with a shift in the methodological focus from reliability and probabilities (expected values) to reliability, uncertainty and risk. In this paper authors explain a novel methodology for risk quantification and ranking the critical items for prioritizing the maintenance actions on the basis of condition-based risk and reliability centered maintenance (CBRRCM). The critical items are identified through criticality analysis of RPN values of items of a system and the maintenance significant precipitating factors (MSPF) of items are evaluated. The criticality of risk is assessed using three risk coefficients. The likelihood risk coefficient treats the probability as a fuzzy number. The abstract risk coefficient deduces risk influenced by uncertainty, sensitivity besides other factors. The third risk coefficient is called hazardous risk coefficient, which is due to anticipated hazards which may occur in the future and the risk is deduced from criteria of consequences on safety, environment, maintenance and economic risks with corresponding cost for consequences. The characteristic values of all the three risk coefficients are obtained with a particular test. With few more tests on the system, the values may change significantly within controlling range of each coefficient, hence `random number simulation' is resorted to obtain one distinctive value for each coefficient. The risk coefficients are statistically added to obtain final risk coefficient of each critical item and then the final rankings of critical items are estimated. The prioritization in ranking of critical items using the developed mathematical model for risk assessment shall be useful in optimization of financial losses and timing of maintenance actions.

  6. Risk of malaria in British residents returning from malarious areas.

    PubMed Central

    Phillips-Howard, P A; Radalowicz, A; Mitchell, J; Bradley, D J

    1990-01-01

    OBJECTIVES--To identify which British residents travelling abroad are at greatest risk of malaria infection, and to determine the efficacy of malaria chemoprophylaxis for preventing P falciparum infections in tropical Africa. DESIGN--Prospective cohort study (case-base linkage) with routine national surveillance systems. Denominators (base population) were obtained from monitoring a random sample of returning British travellers with the international passenger survey. Numerators (cases) were obtained from reports of malaria infections in British residents, through the Malaria Reference Laboratory network. SETTING--International passenger survey conducted at passport control of international airports in Britain. Malaria reports received nationally were collated centrally in London. SUBJECTS--2948 British residents (0.2%) returning to Britain in 1987 randomly selected and questioned and 1052 British residents with microscopically confirmed malaria infections in 1987, whose case reports were reviewed and on whom additional data were collected by postal survey. MAIN OUTCOME MEASURES--Annual incidence subdivided by categories of risk. Chemoprophylactic efficacy for east and west Africa by principal regimens and compliance. RESULTS--Annual rates of reported infection per 100,000 travellers to Oceania were 4100; to west and east Africa were 375 and 172 respectively; to Latin America, the Far East, and the Middle East were 12, 2, and 1 respectively. Immigrants visiting friends and relatives in Ghana and Nigeria were at greatest risk (1303 and 952 per 100,000 respectively) in west Africa. Business travellers to Kenya experienced the highest attack rates in east Africa (465 per 100,000). Age-sex specific attack rates varied by region. No prophylaxis was reported to have been used by 23% of British visitors to west Africa, 17% to east Africa, 46% to central or southern Africa, and 58% visiting south Asia. The efficacy of chloroquine plus proguanil against P falciparum

  7. Malaria risk in Corsica, former hot spot of malaria in France

    PubMed Central

    2010-01-01

    Background The prevalence of Plasmodium falciparum and Plasmodium vivax malaria was very high in Corsica just before the Second World War. The last outbreak was in 1972 and the most recent indigenous case was in 2006. Results Analysis of historical data shows that anopheline vectors were abundant. Recent surveys demonstrated that potential vectors are still present in Corsica, despite the likely disappearance of Anopheles sacharovi. Moreover, P. falciparum can develop experimentally into these mosquitoes, notably Anopheles labranchiae, which is locally abundant, and parasites are regularly introduced into the island. Discussion, Conclusions The presence of vectors, the introduction of parasites and the conducive climate raise questions about the possibility of malaria re-emerging and becoming re-established in Corsica. Analysis of historic and current parasitological and entomological data shows that the current theoretical risk of indigenous cases or malaria foci is negligible, particularly since there is very little contact between humans and Anopheles mosquitoes, Plasmodium carriers are reliably treated and there is a widespread vector control on the island. PMID:20704707

  8. Large-scale malaria survey in Cambodia: novel insights on species distribution and risk factors.

    PubMed

    Incardona, Sandra; Vong, Sirenda; Chiv, Lim; Lim, Pharath; Nhem, Sina; Sem, Rithy; Khim, Nimol; Doung, Socheat; Mercereau-Puijalon, Odile; Fandeur, Thierry

    2007-03-27

    In Cambodia, estimates of the malaria burden rely on a public health information system that does not record cases occurring among remote populations, neither malaria cases treated in the private sector nor asymptomatic carriers. A global estimate of the current malaria situation and associated risk factors is, therefore, still lacking. A large cross-sectional survey was carried out in three areas of multidrug resistant malaria in Cambodia, enrolling 11,652 individuals. Fever and splenomegaly were recorded. Malaria prevalence, parasite densities and spatial distribution of infection were determined to identify parasitological profiles and the associated risk factors useful for improving malaria control programmes in the country. Malaria prevalence was 3.0%, 7.0% and 12.3% in Sampovloun, Koh Kong and Preah Vihear areas. Prevalences and Plasmodium species were heterogeneously distributed, with higher Plasmodium vivax rates in areas of low transmission. Malaria-attributable fevers accounted only for 10-33% of malaria cases, and 23-33% of parasite carriers were febrile. Multivariate multilevel regression analysis identified adults and males, mostly involved in forest activities, as high risk groups in Sampovloun, with additional risks for children in forest-fringe villages in the other areas along with an increased risk with distance from health facilities. These observations point to a more complex malaria situation than suspected from official reports. A large asymptomatic reservoir was observed. The rates of P. vivax infections were higher than recorded in several areas. In remote areas, malaria prevalence was high. This indicates that additional health facilities should be implemented in areas at higher risk, such as remote rural and forested parts of the country, which are not adequately served by health services. Precise malaria risk mapping all over the country is needed to assess the extensive geographical heterogeneity of malaria endemicity and risk

  9. Large-scale malaria survey in Cambodia: Novel insights on species distribution and risk factors

    PubMed Central

    Incardona, Sandra; Vong, Sirenda; Chiv, Lim; Lim, Pharath; Nhem, Sina; Sem, Rithy; Khim, Nimol; Doung, Socheat; Mercereau-Puijalon, Odile; Fandeur, Thierry

    2007-01-01

    Background In Cambodia, estimates of the malaria burden rely on a public health information system that does not record cases occurring among remote populations, neither malaria cases treated in the private sector nor asymptomatic carriers. A global estimate of the current malaria situation and associated risk factors is, therefore, still lacking. Methods A large cross-sectional survey was carried out in three areas of multidrug resistant malaria in Cambodia, enrolling 11,652 individuals. Fever and splenomegaly were recorded. Malaria prevalence, parasite densities and spatial distribution of infection were determined to identify parasitological profiles and the associated risk factors useful for improving malaria control programmes in the country. Results Malaria prevalence was 3.0%, 7.0% and 12.3% in Sampovloun, Koh Kong and Preah Vihear areas. Prevalences and Plasmodium species were heterogeneously distributed, with higher Plasmodium vivax rates in areas of low transmission. Malaria-attributable fevers accounted only for 10–33% of malaria cases, and 23–33% of parasite carriers were febrile. Multivariate multilevel regression analysis identified adults and males, mostly involved in forest activities, as high risk groups in Sampovloun, with additional risks for children in forest-fringe villages in the other areas along with an increased risk with distance from health facilities. Conclusion These observations point to a more complex malaria situation than suspected from official reports. A large asymptomatic reservoir was observed. The rates of P. vivax infections were higher than recorded in several areas. In remote areas, malaria prevalence was high. This indicates that additional health facilities should be implemented in areas at higher risk, such as remote rural and forested parts of the country, which are not adequately served by health services. Precise malaria risk mapping all over the country is needed to assess the extensive geographical heterogeneity

  10. Relative risk estimation for malaria disease mapping based on stochastic SIR-SI model in Malaysia

    NASA Astrophysics Data System (ADS)

    Samat, Nor Azah; Ma'arof, Syafiqah Husna Mohd Imam

    2016-10-01

    Disease mapping is a study on the geographical distribution of a disease to represent the epidemiology data spatially. The production of maps is important to identify areas that deserve closer scrutiny or more attention. In this study, a mosquito-borne disease called Malaria is the focus of our application. Malaria disease is caused by parasites of the genus Plasmodium and is transmitted to people through the bites of infected female Anopheles mosquitoes. Precautionary steps need to be considered in order to avoid the malaria virus from spreading around the world, especially in the tropical and subtropical countries, which would subsequently increase the number of Malaria cases. Thus, the purpose of this paper is to discuss a stochastic model employed to estimate the relative risk of malaria disease in Malaysia. The outcomes of the analysis include a Malaria risk map for all 16 states in Malaysia, revealing the high and low risk areas of Malaria occurrences.

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

    PubMed Central

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

    2015-01-01

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

  12. Action plan to regain unnecessary deferred blood donors due to malaria risk in Turkey.

    PubMed

    Değirmenci, Aysu; Döşkaya, Mert; Caner, Ayşe; Nergis, Sebnem; Gül, Kadri; Aydınok, Yeşim; Ertop, Tufan; Aksoy, Nurten; Korkmaz, Metin; Alkan, Mehmet Ziya; Üner, Ahmet; Gürüz, Yüksel

    2012-06-01

    Malaria was expected to be a major problem during blood donation in Turkey due to existence of malaria cases in southeastern region of Turkey. The present study aimed for the first time, to investigate malaria in "donors deferred for malaria risk" and to determine the regional rates of malaria deferral in Turkey. Blood samples were collected from several Blood Banks of southeastern provinces where local malaria cases still exist and from Blood Bank of Ege University Medical School (EUMS) located in western Turkey where malaria is eradicated decades ago. Plasmodium spp. and specific antibodies were investigated by stained smears, antigen detection, PCR and ELISA. Among the donors deferred for malaria risk, Plasmodium spp. were not detected by microscopy, PCR or antigen detection. Seroprevalances were 2% and 3.92% in western and southeastern regions, respectively. Rate of donor deferral for malaria risk was 0.9% in EUMS and deferrals were exclusively because of travel to southeastern Turkey. In southeastern provinces, deferrals were mainly due to malaria like fever history. The present study first time assessed regional rates of donor deferral due to malaria risk in Turkey. Previously, malaria was expected to be a major problem during blood donation in Turkey due to existence of malaria cases in southeastern region of Turkey. The results of the study showed that 97% of the deferrals were unnecessary. In conclusion, to reduce unnecessary donor deferrals in Turkey, in addition to comprehensive questioning for malaria history, the usage of a malaria antibody screening method should be initiated prior to deferral decision.

  13. Malaria.

    PubMed

    Phillips, Margaret A; Burrows, Jeremy N; Manyando, Christine; van Huijsduijnen, Rob Hooft; Van Voorhis, Wesley C; Wells, Timothy N C

    2017-08-03

    Malaria is caused in humans by five species of single-celled eukaryotic Plasmodium parasites (mainly Plasmodium falciparum and Plasmodium vivax) that are transmitted by the bite of Anopheles spp. mosquitoes. Malaria remains one of the most serious infectious diseases; it threatens nearly half of the world's population and led to hundreds of thousands of deaths in 2015, predominantly among children in Africa. Malaria is managed through a combination of vector control approaches (such as insecticide spraying and the use of insecticide-treated bed nets) and drugs for both treatment and prevention. The widespread use of artemisinin-based combination therapies has contributed to substantial declines in the number of malaria-related deaths; however, the emergence of drug resistance threatens to reverse this progress. Advances in our understanding of the underlying molecular basis of pathogenesis have fuelled the development of new diagnostics, drugs and insecticides. Several new combination therapies are in clinical development that have efficacy against drug-resistant parasites and the potential to be used in single-dose regimens to improve compliance. This ambitious programme to eliminate malaria also includes new approaches that could yield malaria vaccines or novel vector control strategies. However, despite these achievements, a well-coordinated global effort on multiple fronts is needed if malaria elimination is to be achieved.

  14. Malaria Prevalence, Spatial Clustering and Risk Factors in a Low Endemic Area of Eastern Rwanda: A Cross Sectional Study

    PubMed Central

    Bizimana, Jean Pierre; Agaba, Steven; Dukuzumuremyi, Javier; Baas, Lisette; de Dieu Harelimana, Jean; Mens, Petra F.; Boer, Kimberly R.; de Vries, Peter J.

    2013-01-01

    Background Rwanda reported significant reductions in malaria burden following scale up of control intervention from 2005 to 2010. This study sought to; measure malaria prevalence, describe spatial malaria clustering and investigate for malaria risk factors among health-centre-presumed malaria cases and their household members in Eastern Rwanda. Methods A two-stage health centre and household-based survey was conducted in Ruhuha sector, Eastern Rwanda from April to October 2011. At the health centre, data, including malaria diagnosis and individual level malaria risk factors, was collected. At households of these Index cases, a follow-up survey, including malaria screening for all household members and collecting household level malaria risk factor data, was conducted. Results Malaria prevalence among health centre attendees was 22.8%. At the household level, 90 households (out of 520) had at least one malaria-infected member and the overall malaria prevalence for the 2634 household members screened was 5.1%. Among health centre attendees, the age group 5–15 years was significantly associated with an increased malaria risk and a reported ownership of ≥4 bednets was significantly associated with a reduced malaria risk. At the household level, age groups 5–15 and >15 years and being associated with a malaria positive index case were associated with an increased malaria risk, while an observed ownership of ≥4 bednets was associated with a malaria risk-protective effect. Significant spatial malaria clustering among household cases with clusters located close to water- based agro-ecosystems was observed. Conclusions Malaria prevalence was significantly higher among health centre attendees and their household members in an area with significant household spatial malaria clustering. Circle surveillance involving passive case finding at health centres and proactive case detection in households can be a powerful tool for identifying household level malaria burden

  15. The incidence of malaria in travellers to South-East Asia: is local malaria transmission a useful risk indicator?

    PubMed Central

    2010-01-01

    Background The presence of ongoing local malaria transmission, identified though local surveillance and reported to regional WHO offices, by S-E Asian countries, forms the basis of national and international chemoprophylaxis recommendations in western countries. The study was designed to examine whether the strategy of using malaria transmission in a local population was an accurate estimate of the malaria threat faced by travellers and a correlate of malaria in returning travellers. Methods Malaria endemicity was described from distribution and intensity in the local populations of ten S-E Asian destination countries over the period 2003-2008 from regionally reported cases to WHO offices. Travel acquired malaria was collated from malaria surveillance reports from the USA and 12 European countries over the same period. The numbers of travellers visiting the destination countries was based on immigration and tourism statistics collected on entry of tourists to the destination countries. Results In the destination countries, mean malaria rates in endemic countries ranged between 0.01 in Korea to 4:1000 population per year in Lao PDR, with higher regional rates in a number of countries. Malaria cases imported into the 13 countries declined by 47% from 140 cases in 2003 to 66 in 2008. A total of 608 cases (27.3% Plasmodium falciparum (Pf)) were reported over the six years, the largest number acquired in Indonesia, Thailand and Korea. Four countries had an incidence > 1 case per 100,000 traveller visits; Burma (Myanmar), Indonesia, Cambodia and Laos (range 1 to 11.8-case per 100,000 visits). The remaining six countries rates were < 1 case per 100,000 visits. The number of visitors arriving from source countries increased by 60% from 8.5 Million to 13.6 million over the 6 years. Conclusion The intensity of malaria transmission particularly sub-national activity did not correlate with the risk of travellers acquiring malaria in the large numbers of arriving visitors. It

  16. The incidence of malaria in travellers to South-East Asia: is local malaria transmission a useful risk indicator?

    PubMed

    Behrens, Ron H; Carroll, Bernadette; Hellgren, Urban; Visser, Leo G; Siikamäki, Heli; Vestergaard, Lasse S; Calleri, Guido; Jänisch, Thomas; Myrvang, Bjørn; Gascon, Joaquim; Hatz, Christoph

    2010-10-04

    The presence of ongoing local malaria transmission, identified though local surveillance and reported to regional WHO offices, by S-E Asian countries, forms the basis of national and international chemoprophylaxis recommendations in western countries. The study was designed to examine whether the strategy of using malaria transmission in a local population was an accurate estimate of the malaria threat faced by travellers and a correlate of malaria in returning travellers. Malaria endemicity was described from distribution and intensity in the local populations of ten S-E Asian destination countries over the period 2003-2008 from regionally reported cases to WHO offices. Travel acquired malaria was collated from malaria surveillance reports from the USA and 12 European countries over the same period. The numbers of travellers visiting the destination countries was based on immigration and tourism statistics collected on entry of tourists to the destination countries. In the destination countries, mean malaria rates in endemic countries ranged between 0.01 in Korea to 4:1000 population per year in Lao PDR, with higher regional rates in a number of countries. Malaria cases imported into the 13 countries declined by 47% from 140 cases in 2003 to 66 in 2008. A total of 608 cases (27.3% Plasmodium falciparum (Pf)) were reported over the six years, the largest number acquired in Indonesia, Thailand and Korea. Four countries had an incidence > 1 case per 100,000 traveller visits; Burma (Myanmar), Indonesia, Cambodia and Laos (range 1 to 11.8-case per 100,000 visits). The remaining six countries rates were < 1 case per 100,000 visits. The number of visitors arriving from source countries increased by 60% from 8.5 Million to 13.6 million over the 6 years. The intensity of malaria transmission particularly sub-national activity did not correlate with the risk of travellers acquiring malaria in the large numbers of arriving visitors. It is proposed to use a threshold

  17. Measuring Socioeconomic Inequalities in Relation to Malaria Risk: A Comparison of Metrics in Rural Uganda

    PubMed Central

    Tusting, Lucy S.; Rek, John C.; Arinaitwe, Emmanuel; Staedke, Sarah G.; Kamya, Moses R.; Bottomley, Christian; Johnston, Deborah; Lines, Jo; Dorsey, Grant; Lindsay, Steve W.

    2016-01-01

    Socioeconomic position (SEP) is an important risk factor for malaria, but there is no consensus on how to measure SEP in malaria studies. We evaluated the relative strength of four indicators of SEP in predicting malaria risk in Nagongera, Uganda. A total of 318 children resident in 100 households were followed for 36 months to measure parasite prevalence routinely every 3 months and malaria incidence by passive case detection. Household SEP was determined using: 1) two wealth indices, 2) income, 3) occupation, and 4) education. Wealth Index I (reference) included only asset ownership variables. Wealth Index II additionally included food security and house construction variables, which may directly affect malaria. In multivariate analysis, only Wealth Index II and income were associated with the human biting rate, only Wealth Indices I and II were associated with parasite prevalence, and only caregiver's education was associated with malaria incidence. This is the first evaluation of metrics beyond wealth and consumption indices for measuring the association between SEP and malaria. The wealth index still predicted malaria risk after excluding variables directly associated with malaria, but the strength of association was lower. In this setting, wealth indices, income, and education were stronger predictors of socioeconomic differences in malaria risk than occupation. PMID:26811432

  18. Investigation of host candidate malaria-associated risk/protective SNPs in a Brazilian Amazonian population.

    PubMed

    da Silva Santos, Simone; Clark, Taane G; Campino, Susana; Suarez-Mutis, Martha Cecília; Rockett, Kirk A; Kwiatkowski, Dominic P; Fernandes, Octavio

    2012-01-01

    The Brazilian Amazon is a hypo-endemic malaria region with nearly 300,000 cases each year. A variety of genetic polymorphisms, particularly in erythrocyte receptors and immune response related genes, have been described to be associated with susceptibility and resistance to malaria. In order to identify polymorphisms that might be associated with malaria clinical outcomes in a Brazilian Amazonian population, sixty-four human single nucleotide polymorphisms in 37 genes were analyzed using a Sequenom massARRAY iPLEX platform. A total of 648 individuals from two malaria endemic areas were studied, including 535 malaria cases (113 individuals with clinical mild malaria, 122 individuals with asymptomatic infection and 300 individuals with history of previous mild malaria) and 113 health controls with no history of malaria. The data revealed significant associations (p<0.003) between one SNP in the IL10 gene (rs1800896) and one SNP in the TLR4 gene (rs4986790) with reduced risk for clinical malaria, one SNP in the IRF1 gene (rs2706384) with increased risk for clinical malaria, one SNP in the LTA gene (rs909253) with protection from clinical malaria and one SNP in the TNF gene (RS1800750) associated with susceptibility to clinical malaria. Also, a new association was found between a SNP in the CTL4 gene (rs2242665), located at the major histocompatibility complex III region, and reduced risk for clinical malaria. This study represents the first association study from an Amazonian population involving a large number of host genetic polymorphisms with susceptibility or resistance to Plasmodium infection and malaria outcomes. Further studies should include a larger number of individuals, refined parameters and a fine-scale map obtained through DNA sequencing to increase the knowledge of the Amazonian population genetic diversity.

  19. Different actuarial risk measures produce different risk rankings for sexual offenders.

    PubMed

    Barbaree, Howard E; Langton, Calvin M; Peacock, Edward J

    2006-10-01

    Percentile ranks were computed for N=262 sex offenders using each of 5 actuarial risk instruments commonly used with adult sex offenders (RRASOR, Static-99, VRAG, SORAG, and MnSOST-R). Mean differences between percentile ranks obtained by different actuarial measures were found to vary inversely with the correlation between the actuarial scores. Following studies of factor analyses of actuarial items, we argue that the discrepancies among actuarial instruments can be substantially accounted for by the way in which the factor Antisocial Behavior and various factors reflecting sexual deviance are represented among the items contained in each instrument. In the discussion, we provide guidance to clinicians in resolving discrepancies between instruments and we discuss implications for future developments in sex offender risk assessment.

  20. Ranking the risk of wildlife species hazardous to military aircraft

    USGS Publications Warehouse

    Zakrajsek, E.J.; Bissonette, J.A.

    2005-01-01

    Collisions between birds and aircraft (birdstrikes) pose a major threat to aviation safety. Different species pose different levels of threat; thus, identification of the most hazardous species can help managers identify the level of hazard and prioritize mitigation efforts. Dolbeer et al. (2000) assessed the hazard posed by birds to civilian aircraft by analyzing data from the Federal Aviation Administration's (FAA) Wildlife Strike Database to rank the hazardous species and species groups. A similar analysis has not been done for the military but would be useful and necessary. Military flight characteristics differ from those of civilian flights. During the period 1985-1998, birdstrikes cost the United States Air Force (USAF) an average of $35 million/year in damage. Using the USAF Birdstrike Database, we selected and evaluated each species or species group by the number of strikes recorded in each of 3 damage categories. We weighted damage categories to reflect extent and cost of damage. The USAF Birdstrike Database contained 25,519 records of wildlife strikes in the United States. During the period 1985-1998, 22 (mean = 1.6/year) Class-A birdstrikes (>$1,000,000 damage, loss of aircraft, loss of life, or permanent total disability) were sustained, accounting for 80% of total monetary losses caused by birds. Vultures (Cathartes aura, Coragyps atratus, Caracara cheriway) were ranked the most hazardous species group (Hazard Index Rank [HIR] = 127) to USAF aircraft, followed by geese (Branta canadensis, Chen caerulescens, HIR = 76), pelicans (Pelecanus erythrorhynchos, P. occidentalis, HIR = 47), and buteos (Buteo sp., HIR = 30). Of the smaller flocking birds, blackbirds and starlings (mostly Agelaius phoeniceus, Euphagus cyanocephalus, Molothrus ater, Sturnus vulgaris, HIR = 46), horned larks (Eremophila alpestris, HIR = 24), and swallows (Families Hirundinidae, Apodidae, HIR = 23) were species groups ranked highest. Coupling these results with local bird census

  1. [Food and nutritional security in a risk area for malaria].

    PubMed

    Guzmán, Valentina; Correa, Adriana María; Carmona-Fonseca, Jaime; Blair, Silvia

    2003-09-01

    To explore some relationships between alimentary and nutritional security (SAN) and nutritional status in an endemic malaria community, applying qualitative and quantitative methods simultaneously. The study was descriptive and prospective. The population were all farming Afro-American families who live in the basin of the river Valle (Bahía Solano. Chocó, Colombia) that derived the base of their feeding of the agriculture. The SAN was measured from the monthly availability of foods and was classified in adequate and inadequate according to the available monthly caloric balance percentage. We determined the risk of acute malnutrition (indicative P/T), chronic (T/E), global (P/E) and risk of thinness (BMI). We sought for malarian cases. The official data of illness were revised. We applied surveys to know the morbidity and knowledge, attitudes and practices in malaria infections, 29% of homes had alimentary insecurity. There was protein deficit and iron of high availability, calcium and vitamin A in 100% of families. In children under 6 years old, we found 31% and 69%, in same order, with low P/T and T/E, while in the 6-10 year old children had 14% and 41%, respectively. In adolescents (11 to 17 years old) the risk of thinness was 15% and in adults 3%. There was not association between alimentary available and family nutritional status. These results suggest subclinics deficiencies of micronutrients.

  2. International Funding for Malaria Control in Relation to Populations at Risk of Stable Plasmodium falciparum Transmission

    PubMed Central

    Snow, Robert W; Guerra, Carlos A; Mutheu, Juliette J; Hay, Simon I

    2008-01-01

    Background The international financing of malaria control has increased significantly in the last ten years in parallel with calls to halve the malaria burden by the year 2015. The allocation of funds to countries should reflect the size of the populations at risk of infection, disease, and death. To examine this relationship, we compare an audit of international commitments with an objective assessment of national need: the population at risk of stable Plasmodium falciparum malaria transmission in 2007. Methods and Findings The national distributions of populations at risk of stable P. falciparum transmission were projected to the year 2007 for each of 87 P. falciparum–endemic countries. Systematic online- and literature-based searches were conducted to audit the international funding commitments made for malaria control by major donors between 2002 and 2007. These figures were used to generate annual malaria funding allocation (in US dollars) per capita population at risk of stable P. falciparum in 2007. Almost US$1 billion are distributed each year to the 1.4 billion people exposed to stable P. falciparum malaria risk. This is less than US$1 per person at risk per year. Forty percent of this total comes from the Global Fund to Fight AIDS, Tuberculosis and Malaria. Substantial regional and national variations in disbursements exist. While the distribution of funds is found to be broadly appropriate, specific high population density countries receive disproportionately less support to scale up malaria control. Additionally, an inadequacy of current financial commitments by the international community was found: under-funding could be from 50% to 450%, depending on which global assessment of the cost required to scale up malaria control is adopted. Conclusions Without further increases in funding and appropriate targeting of global malaria control investment it is unlikely that international goals to halve disease burdens by 2015 will be achieved. Moreover, the

  3. Targeting populations at higher risk for malaria: a survey of national malaria elimination programmes in the Asia Pacific.

    PubMed

    Wen, Shawn; Harvard, Kelly E; Gueye, Cara Smith; Canavati, Sara E; Chancellor, Arna; Ahmed, Be-Nazir; Leaburi, John; Lek, Dysoley; Namgay, Rinzin; Surya, Asik; Thakur, Garib D; Whittaker, Maxine Anne; Gosling, Roly D

    2016-05-10

    Significant progress has been made in reducing the malaria burden in the Asia Pacific region, which is aggressively pursuing a 2030 regional elimination goal. Moving from malaria control to elimination requires National Malaria Control Programmes (NMCPs) to target interventions at populations at higher risk, who are often not reached by health services, highly mobile and difficult to test, treat, and track with routine measures, and if undiagnosed, can maintain parasite reservoirs and contribute to ongoing transmission. A qualitative, free-text questionnaire was developed and disseminated among 17 of the 18 partner countries of the Asia Pacific Malaria Elimination Network (APMEN). All 14 countries that responded to the survey identified key populations at higher risk of malaria in their respective countries. Thirteen countries engage in the dissemination of malaria-related Information, Education, and Communication (IEC) materials. Eight countries engage in diagnostic screening, including of mobile and migrant workers, military staff, and/or overseas workers. Ten countries reported distributing or recommending the use of long-lasting insecticide-treated nets (LLINs) among populations at higher risk with fewer countries engaging in other prevention measures such as indoor residual spraying (IRS) (two countries), spatial repellents (four countries), chemoprophylaxis (five countries), and mass drug administration (MDA) (three countries). Though not specifically tailored to populations at higher risk, 11 countries reported using mass blood surveys as a surveillance tool and ten countries map case data. Most NMCPs lack a monitoring and evaluation structure. Countries in the Asia Pacific have identified populations at higher risk and targeted interventions to these groups but there is limited information on the effectiveness of these interventions. Platforms like APMEN offer the opportunity for the sharing of protocols and lessons learned related to finding, targeting and

  4. Early-childhood obesity: how do low-income parents of preschoolers rank known risk factors?

    PubMed

    Hernandez, Raquel G; Thompson, Darcy A; Cheng, Tina L; Serwint, Janet R

    2012-07-01

    To determine parental rankings of known factors related to early-childhood obesity and compare reports between parents of healthy weight and overweight children. Parents of 2- to 5-year-old children seeking well-child care ranked card-sort statements including risks, barriers, and motivating factors for achieving a healthy weight child. Frequencies and means of ranked factors are reported and compared. Of the 150 participants, few parents (7.4%) considered low levels of physical activity a top risk factor compared with other known risks. Inability to control the food choices of alternate caregivers was the greatest perceived barrier to achieving a healthy child weight (34%). There were no differences in rankings by child weight groups. Low-income parents of preschoolers are aware of high-risk feeding behaviors, but few recognize the risk of inactivity in their young child. Innovations that promote adequate physical activity and engage influential caregivers during counseling are necessary.

  5. A cross-sectional analysis of traditional medicine use for malaria alongside free antimalarial drugs treatment amongst adults in high-risk malaria endemic provinces of Indonesia.

    PubMed

    Suswardany, Dwi Linna; Sibbritt, David W; Supardi, Sudibyo; Pardosi, Jerico F; Chang, Sungwon; Adams, Jon

    2017-01-01

    The level of traditional medicine use, particularly Jamu use, in Indonesia is substantial. Indonesians do not always seek timely treatment for malaria and may seek self-medication via traditional medicine. This paper reports findings from the first focused analyses of traditional medicine use for malaria in Indonesia and the first such analyses worldwide to draw upon a large sample of respondents across high-risk malaria endemic areas. A sub-study of the Indonesia Basic Health Research/Riskesdas Study 2010 focused on 12,226 adults aged 15 years and above residing in high-risk malaria-endemic provinces. Logistic regression was undertaken to determine the significant associations for traditional medicine use for malaria symptoms. Approximately one in five respondents use traditional medicine for malaria symptoms and the vast majority experiencing multiple episodes of malaria use traditional medicine alongside free antimalarial drug treatments. Respondents consuming traditional medicine for general health/common illness purposes every day (odds ratio: 3.75, 95% Confidence Interval: 2.93 4.79), those without a hospital in local vicinity (odds ratio: 1.31, 95% Confidence Interval: 1.10 1.57), and those living in poorer quality housing, were more likely to use traditional medicine for malaria symptoms. A substantial percentage of those with malaria symptoms utilize traditional medicine for treating their malaria symptoms. In order to promote safe and effective malaria treatment, all providing malaria care in Indonesia need to enquire with their patients about possible traditional medicine use.

  6. Estimating Geographical Variation in the Risk of Zoonotic Plasmodium knowlesi Infection in Countries Eliminating Malaria.

    PubMed

    Shearer, Freya M; Huang, Zhi; Weiss, Daniel J; Wiebe, Antoinette; Gibson, Harry S; Battle, Katherine E; Pigott, David M; Brady, Oliver J; Putaporntip, Chaturong; Jongwutiwes, Somchai; Lau, Yee Ling; Manske, Magnus; Amato, Roberto; Elyazar, Iqbal R F; Vythilingam, Indra; Bhatt, Samir; Gething, Peter W; Singh, Balbir; Golding, Nick; Hay, Simon I; Moyes, Catherine L

    2016-08-01

    Infection by the simian malaria parasite, Plasmodium knowlesi, can lead to severe and fatal disease in humans, and is the most common cause of malaria in parts of Malaysia. Despite being a serious public health concern, the geographical distribution of P. knowlesi malaria risk is poorly understood because the parasite is often misidentified as one of the human malarias. Human cases have been confirmed in at least nine Southeast Asian countries, many of which are making progress towards eliminating the human malarias. Understanding the geographical distribution of P. knowlesi is important for identifying areas where malaria transmission will continue after the human malarias have been eliminated. A total of 439 records of P. knowlesi infections in humans, macaque reservoir and vector species were collated. To predict spatial variation in disease risk, a model was fitted using records from countries where the infection data coverage is high. Predictions were then made throughout Southeast Asia, including regions where infection data are sparse. The resulting map predicts areas of high risk for P. knowlesi infection in a number of countries that are forecast to be malaria-free by 2025 (Malaysia, Cambodia, Thailand and Vietnam) as well as countries projected to be eliminating malaria (Myanmar, Laos, Indonesia and the Philippines). We have produced the first map of P. knowlesi malaria risk, at a fine-scale resolution, to identify priority areas for surveillance based on regions with sparse data and high estimated risk. Our map provides an initial evidence base to better understand the spatial distribution of this disease and its potential wider contribution to malaria incidence. Considering malaria elimination goals, areas for prioritised surveillance are identified.

  7. Estimating Geographical Variation in the Risk of Zoonotic Plasmodium knowlesi Infection in Countries Eliminating Malaria

    PubMed Central

    Shearer, Freya M.; Huang, Zhi; Weiss, Daniel J.; Wiebe, Antoinette; Gibson, Harry S.; Battle, Katherine E.; Pigott, David M.; Brady, Oliver J.; Putaporntip, Chaturong; Jongwutiwes, Somchai; Lau, Yee Ling; Manske, Magnus; Amato, Roberto; Elyazar, Iqbal R. F.; Vythilingam, Indra; Bhatt, Samir; Gething, Peter W.; Singh, Balbir; Golding, Nick; Hay, Simon I.

    2016-01-01

    Background Infection by the simian malaria parasite, Plasmodium knowlesi, can lead to severe and fatal disease in humans, and is the most common cause of malaria in parts of Malaysia. Despite being a serious public health concern, the geographical distribution of P. knowlesi malaria risk is poorly understood because the parasite is often misidentified as one of the human malarias. Human cases have been confirmed in at least nine Southeast Asian countries, many of which are making progress towards eliminating the human malarias. Understanding the geographical distribution of P. knowlesi is important for identifying areas where malaria transmission will continue after the human malarias have been eliminated. Methodology/Principal Findings A total of 439 records of P. knowlesi infections in humans, macaque reservoir and vector species were collated. To predict spatial variation in disease risk, a model was fitted using records from countries where the infection data coverage is high. Predictions were then made throughout Southeast Asia, including regions where infection data are sparse. The resulting map predicts areas of high risk for P. knowlesi infection in a number of countries that are forecast to be malaria-free by 2025 (Malaysia, Cambodia, Thailand and Vietnam) as well as countries projected to be eliminating malaria (Myanmar, Laos, Indonesia and the Philippines). Conclusions/Significance We have produced the first map of P. knowlesi malaria risk, at a fine-scale resolution, to identify priority areas for surveillance based on regions with sparse data and high estimated risk. Our map provides an initial evidence base to better understand the spatial distribution of this disease and its potential wider contribution to malaria incidence. Considering malaria elimination goals, areas for prioritised surveillance are identified. PMID:27494405

  8. Preparation for malaria resurgence in China: approach in risk assessment and rapid response.

    PubMed

    Qian, Ying-Jun; Zhang, Li; Xia, Zhi-Gui; Vong, Sirenda; Yang, Wei-Zhong; Wang, Duo-Quan; Xiao, Ning

    2014-01-01

    With the shrinking of indigenous malaria cases and endemic areas in the People's Republic of China (P.R. China), imported malaria predominates over all reported cases accounting for more than 90% of the total. On the way to eliminate malaria, prompt detection and rapid response to the imported cases are crucial for the prevention of secondary transmission in previous endemic areas. Through a comprehensive literature review, this chapter aims to identify risk determinants of potential local transmission caused by the imported malaria cases and discusses gaps to be addressed to reach the elimination goal by 2020. Current main gaps with respect to dealing with potential malaria resurgence in P.R. China include lack of cross-sectoral cooperation, lack of rapid response and risk assessment, poor public awareness, and inadequate research and development in the national malaria elimination programme. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Cost risk benefit analysis to support chemoprophylaxis policy for travellers to malaria endemic countries

    PubMed Central

    2011-01-01

    Background In a number of malaria endemic regions, tourists and travellers face a declining risk of travel associated malaria, in part due to successful malaria control. Many millions of visitors to these regions are recommended, via national and international policy, to use chemoprophylaxis which has a well recognized morbidity profile. To evaluate whether current malaria chemo-prophylactic policy for travellers is cost effective when adjusted for endemic transmission risk and duration of exposure. a framework, based on partial cost-benefit analysis was used Methods Using a three component model combining a probability component, a cost component and a malaria risk component, the study estimated health costs avoided through use of chemoprophylaxis and costs of disease prevention (including adverse events and pre-travel advice for visits to five popular high and low malaria endemic regions) and malaria transmission risk using imported malaria cases and numbers of travellers to malarious countries. By calculating the minimal threshold malaria risk below which the economic costs of chemoprophylaxis are greater than the avoided health costs we were able to identify the point at which chemoprophylaxis would be economically rational. Results The threshold incidence at which malaria chemoprophylaxis policy becomes cost effective for UK travellers is an accumulated risk of 1.13% assuming a given set of cost parameters. The period a travellers need to remain exposed to achieve this accumulated risk varied from 30 to more than 365 days, depending on the regions intensity of malaria transmission. Conclusions The cost-benefit analysis identified that chemoprophylaxis use was not a cost-effective policy for travellers to Thailand or the Amazon region of Brazil, but was cost-effective for travel to West Africa and for those staying longer than 45 days in India and Indonesia. PMID:21586155

  10. Malaria.

    PubMed

    Heck, J E

    1991-03-01

    Human malaria is caused by four species of the genus plasmodium. The sexual stage of the parasite occurs in the mosquito and asexual reproduction occurs in man. Symptoms of fever, chills, headache, and myalgia result from the invasion and rupture of erythrocytes. Merozoites are released from erythrocytes and invade other cells, thus propagating the infection. The most vulnerable hosts are nonimmune travelers, young children living in the tropics, and pregnant women. P. falciparum causes the most severe infections because it infects RBCs of all ages and has the propensity to develop resistance to antimalarials. Rapid diagnosis can be made with a malarial smear, and treatment should be initiated promptly. In some regions (Mexico, Central America except Panama, and North Africa) chloroquine phosphate is effective therapy. In subsaharan Africa, South America, and Southeast Asia, chloroquine resistance has become widespread, and other antimalarials are necessary. The primary care physician should have a high index of suspicion for malaria in the traveler returning from the tropics. Malaria should also be suspected in the febrile transfusion recipient and newborns of mothers with malaria.

  11. Knowledge, attitudes, and practices among foreign backpackers toward malaria risk in southeast Asia.

    PubMed

    Piyaphanee, Watcharapong; Wattanagoon, Yupaporn; Silachamroon, Udomsak; Mansanguan, Chayasin; Wichianprasat, Pongdej; Walker, Eric

    2009-01-01

    Malaria is still prevalent in Southeast Asia where large numbers of backpackers visit each year. This study aimed to assess the knowledge, attitude, and practices among foreign backpackers toward malaria risk in Southeast Asia. Questionnaires were administered to foreign backpackers in Bangkok, Thailand. They were asked about their general background, their attitude to malaria risk, and their preventive measures against malaria. Their knowledge about malaria was assessed by 10 true-false questions in the questionnaires. In total, 434 questionnaires were evaluated. Fifty-five percent of travelers were male and the median age was 28 years. The main reason for travel was tourism (91%). Almost all travelers (94%) were aware of the risk of malaria. Twenty-two percent of them would take antimalarial prophylaxis and 33% would use measures against mosquito bite, but nearly 40% had "no prevention" at all. Mean knowledge score was only 5.52 of 10. Most backpackers (92%) knew that malaria is a serious disease and sometime fatal and 74% knew that some travelers could develop malaria after they return. However, up to 35% believed that eating contaminated food could lead to malaria infection. And 49% believed that malaria could be 100% prevented by chemoprophylaxis. In backpackers, who had traveled in the forest (n = 65), only 54% used insect repellent regularly. Among those who had taken antimalarial prophylaxis, nearly 30% had stopped the medication prematurely. Although most backpackers perceive the risk of malaria in Southeast Asia, they have some misunderstandings about malaria and tend to comply poorly with mosquito bite prevention and chemoprophylactic strategies.

  12. Applications of fuzzy ranking methods to risk-management decisions

    NASA Astrophysics Data System (ADS)

    Mitchell, Harold A.; Carter, James C., III

    1993-12-01

    The Department of Energy is making significant improvements to its nuclear facilities as a result of more stringent regulation, internal audits, and recommendations from external review groups. A large backlog of upgrades has resulted. Currently, a prioritization method is being utilized which relies on a matrix of potential consequence and probability of occurrence. The attributes of the potential consequences considered include likelihood, exposure, public health and safety, environmental impact, site personnel safety, public relations, legal liability, and business loss. This paper describes an improved method which utilizes fuzzy multiple attribute decision methods to rank proposed improvement projects.

  13. Malaria and Travelers

    MedlinePlus

    ... a CDC Malaria Branch clinician. malaria@cdc.gov Malaria and Travelers Recommend on Facebook Tweet Share Compartir ... may be at risk for infection. Determine if malaria transmission occurs at the destinations Obtain a detailed ...

  14. Assessing Malaria Risks in Greater Mekong Subregion based on Environmental Parameters

    NASA Technical Reports Server (NTRS)

    Kiang, Richard; Soika, Valerii; Adimi, Farida; Nigro, Joseph

    2005-01-01

    At 4,200 km, the Mekong River is the tenth longest river in the world. It directly and indirectly influences the lives of hundreds of millions of inhabitants in its basin. The riparian countries - Thailand, Myanmar, Cambodia, Laos, Vietnam, and a small part of China - form the Greater Mekong Subregion (GMS). This geographical region has the misfortune of being the world's epicenter of falciparum malaria, which is the most severe form of malaria caused by Plasmodium falciparum. Depending on the country, approximately 50 to 90% of all malaria cases are due to this species. In the Malaria Modeling and Surveillance Project, we have been developing techniques to enhance public health s decision capability for malaria risk assessments and controls. The main objectives are: 1) identifying the potential breeding sites for major vector species; 2) implementing a malaria transmission model to identify the key factors that sustain or intensify malaria transmission; and 3) implementing a risk algorithm to predict the occurrence of malaria and its transmission intensity. The potential benefits are: 1) increased warning time for public health organizations to respond to malaria outbreaks; 2) optimized utilization of pesticide and chemoprophylaxis; 3) reduced likelihood of pesticide and drug resistance; and 4) reduced damage to environment. Environmental parameters important to malaria transmission include temperature, relative humidity, precipitation, and vegetation conditions. The NASA Earth science data sets that have been used for malaria surveillance and risk assessment include AVHRR Pathfinder, TRMM, MODIS, NSIPP, and SIESIP. Hindcastings based on these environmental parameters have shown good agreement to epidemiological records. Socioeconomic factors that may influence malaria transmissions will also be incorporated into the predictive models.

  15. The global distribution and population at risk of malaria: past, present, and future

    PubMed Central

    Hay, Simon I; Guerra, Carlos A; Tatem, Andrew J; Noor, Abdisalan M; Snow, Robert W

    2011-01-01

    The aim of this review was to use geographic information systems in combination with historical maps to quantify the anthropogenic impact on the distribution of malaria in the 20th century. The nature of the cartographic record enabled global and regional patterns in the spatial limits of malaria to be investigated at six intervals between 1900 and 2002. Contemporaneous population surfaces also allowed changes in the numbers of people living in areas of malaria risk to be quantified. These data showed that during the past century, despite human activities reducing by half the land area supporting malaria, demographic changes resulted in a 2 billion increase in the total population exposed to malaria risk. Furthermore, stratifying the present day malaria extent by endemicity class and examining regional differences highlighted that nearly 1 billion people are exposed to hypoendemic and mesoendemic malaria in southeast Asia. We further concluded that some distortion in estimates of the regional distribution of malaria burden could have resulted from different methods used to calculate burden in Africa. Crude estimates of the national prevalence of Plasmodium falciparum infection based on endemicity maps corroborate these assertions. Finally, population projections for 2010 were used to investigate the potential effect of future demographic changes. These indicated that although population growth will not substantially change the regional distribution of people at malaria risk, around 400 million births will occur within the boundary of current distribution of malaria by 2010: the date by which the Roll Back Malaria initiative is challenged to halve the world’s malaria burden. PMID:15172341

  16. Assessing Malaria Risks in Greater Mekong Subregion based on Environmental Parameters

    NASA Technical Reports Server (NTRS)

    Kiang, Richard; Soika, Valerii; Adimi, Farida; Nigro, Joseph

    2005-01-01

    At 4,200 km, the Mekong River is the tenth longest river in the world. It directly and indirectly influences the lives of hundreds of millions of inhabitants in its basin. The riparian countries - Thailand, Myanmar, Cambodia, Laos, Vietnam, and a small part of China - form the Greater Mekong Subregion (GMS). This geographical region has the misfortune of being the world's epicenter of falciparum malaria, which is the most severe form of malaria caused by Plasmodium falciparum. Depending on the country, approximately 50 to 90% of all malaria cases are due to this species. In the Malaria Modeling and Surveillance Project, we have been developing techniques to enhance public health s decision capability for malaria risk assessments and controls. The main objectives are: 1) identifying the potential breeding sites for major vector species; 2) implementing a malaria transmission model to identify the key factors that sustain or intensify malaria transmission; and 3) implementing a risk algorithm to predict the occurrence of malaria and its transmission intensity. The potential benefits are: 1) increased warning time for public health organizations to respond to malaria outbreaks; 2) optimized utilization of pesticide and chemoprophylaxis; 3) reduced likelihood of pesticide and drug resistance; and 4) reduced damage to environment. Environmental parameters important to malaria transmission include temperature, relative humidity, precipitation, and vegetation conditions. The NASA Earth science data sets that have been used for malaria surveillance and risk assessment include AVHRR Pathfinder, TRMM, MODIS, NSIPP, and SIESIP. Hindcastings based on these environmental parameters have shown good agreement to epidemiological records. Socioeconomic factors that may influence malaria transmissions will also be incorporated into the predictive models.

  17. Dietary risk ranking for residual antibiotics in cultured aquatic products around Tai Lake, China.

    PubMed

    Song, Chao; Li, Le; Zhang, Cong; Qiu, Liping; Fan, Limin; Wu, Wei; Meng, Shunlong; Hu, Gengdong; Chen, Jiazhang; Liu, Ying; Mao, Aimin

    2017-10-01

    Antibiotics are widely used in aquaculture and therefore may be present as a dietary risk in cultured aquatic products. Using the Tai Lake Basin as a study area, we assessed the presence of 15 antibiotics in 5 widely cultured aquatic species using a newly developed dietary risk ranking approach. By assigning scores to each factor involved in the ranking matrices, the scores of dietary risks per antibiotic and per aquatic species were calculated. The results indicated that fluoroquinolone antibiotics posed the highest dietary risk in all aquatic species. Then, the total scores per aquatic species were summed by all 15 antibiotic scores of antibiotics, it was found that Crab (Eriocheir sinensis) had the highest dietary risks. Finally, the most concerned antibiotic category and aquatic species were selected. This study highlighted the importance of dietary risk ranking in the production and consumption of cultured aquatic products around Tai Lake. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Risk-Based Ranking Experiences for Cold War Legacy Facilities in the United States

    SciTech Connect

    Droppo, James G.

    2003-05-01

    Over the past two decades, a number of government agencies in the United States have faced increasing public scrutiny for their efforts to address the wide range of potential environmental issues related to Cold War legacies. Risk-based ranking was selected as a means of defining the relative importance of issues. Ambitious facility-wide risk-based ranking applications were undertaken. However, although facility-wide risk-based ranking efforts can build invaluable understanding of the potential issues related to Cold War legacies, conducting such efforts is difficult because of the potentially enormous scope and the potentially strong institutional barriers. The U.S. experience is that such efforts are worth undertaking to start building a knowledge base and infrastructure that are based on a thorough understanding of risk. In both the East and the West, the legacy of the Cold War includes a wide range of potential environmental issues associated with large industrial complexes of weapon production facilities. The responsible agencies or ministries are required to make decisions that could benefit greatly from information on the relative importance of these potential issues. Facility-wide risk-based ranking of potential health and environmental issues is one means to help these decision makers. The initial U.S. risk-based ranking applications described in this chapter were “ground-breaking” in that they defined new methodologies and approaches to meet the challenges. Many of these approaches fit the designation of a population-centred risk assessment. These U.S. activities parallel efforts that are just beginning for similar facilities in the countries of the former Soviet Union. As described below, conducting a facility-wide risk-based ranking has special challenges and potential pitfalls. Little guidance exists to conduct major risk-based rankings. For those considering undertaking such efforts, the material contained in this chapter should be useful

  19. Visualizing the uncertainty in the relationship between seasonal average climate and malaria risk.

    PubMed

    MacLeod, D A; Morse, A P

    2014-12-02

    Around $1.6 billion per year is spent financing anti-malaria initiatives, and though malaria morbidity is falling, the impact of annual epidemics remains significant. Whilst malaria risk may increase with climate change, projections are highly uncertain and to sidestep this intractable uncertainty, adaptation efforts should improve societal ability to anticipate and mitigate individual events. Anticipation of climate-related events is made possible by seasonal climate forecasting, from which warnings of anomalous seasonal average temperature and rainfall, months in advance are possible. Seasonal climate hindcasts have been used to drive climate-based models for malaria, showing significant skill for observed malaria incidence. However, the relationship between seasonal average climate and malaria risk remains unquantified. Here we explore this relationship, using a dynamic weather-driven malaria model. We also quantify key uncertainty in the malaria model, by introducing variability in one of the first order uncertainties in model formulation. Results are visualized as location-specific impact surfaces: easily integrated with ensemble seasonal climate forecasts, and intuitively communicating quantified uncertainty. Methods are demonstrated for two epidemic regions, and are not limited to malaria modeling; the visualization method could be applied to any climate impact.

  20. Visualizing the uncertainty in the relationship between seasonal average climate and malaria risk

    NASA Astrophysics Data System (ADS)

    MacLeod, D. A.; Morse, A. P.

    2014-12-01

    Around $1.6 billion per year is spent financing anti-malaria initiatives, and though malaria morbidity is falling, the impact of annual epidemics remains significant. Whilst malaria risk may increase with climate change, projections are highly uncertain and to sidestep this intractable uncertainty, adaptation efforts should improve societal ability to anticipate and mitigate individual events. Anticipation of climate-related events is made possible by seasonal climate forecasting, from which warnings of anomalous seasonal average temperature and rainfall, months in advance are possible. Seasonal climate hindcasts have been used to drive climate-based models for malaria, showing significant skill for observed malaria incidence. However, the relationship between seasonal average climate and malaria risk remains unquantified. Here we explore this relationship, using a dynamic weather-driven malaria model. We also quantify key uncertainty in the malaria model, by introducing variability in one of the first order uncertainties in model formulation. Results are visualized as location-specific impact surfaces: easily integrated with ensemble seasonal climate forecasts, and intuitively communicating quantified uncertainty. Methods are demonstrated for two epidemic regions, and are not limited to malaria modeling; the visualization method could be applied to any climate impact.

  1. Novel ellipsoid spatial analysis for determining malaria risk at the village level.

    PubMed

    Lek-Uthai, Usa; Sangsayan, Jare; Kachenchart, Boonlue; Kulpradit, Kasem; Sujirarat, Dusit; Honda, Kiyoshi

    2010-10-01

    The distribution patterns of malaria incidence at a village level in Thailand were demonstrated with the use of a geographical information system (GIS), and provided the study of the malaria situation at a household level. Mosaic imageries from aerial photographs were used to create maps that contained X and Y coordinates. These digitized base maps were kept as computerized files. Standard Distance Ellipse (SDE) was used to measure the prevalence of dispersion around the mean center of malaria cases and points. Households in the SDE were at greater risk of malaria infection than those located outside the SDE. The spatial pattern of malaria incidence was investigated using spatial autocorrelation using Geary's ratio and Moran's index. Five of seven villages had a clustered spatial distribution of malaria incidence, the vector point of which had a 2-3km range from the patient's houses. Only one village had a significant clustered spatial distribution of malaria incidence (p<0.05). Control efforts should be focused on high-risk areas, especially those households with the heaviest caseloads. This approach would probably be more cost effective than the conventional malaria control methods. This SDE analytical technique would be a novel and useful epidemiological control method for use by public health administrators. The ellipsoidal areas required malaria control intervention. Copyright 2010 Elsevier B.V. All rights reserved.

  2. Visualizing the uncertainty in the relationship between seasonal average climate and malaria risk

    PubMed Central

    MacLeod, D. A.; Morse, A. P.

    2014-01-01

    Around $1.6 billion per year is spent financing anti-malaria initiatives, and though malaria morbidity is falling, the impact of annual epidemics remains significant. Whilst malaria risk may increase with climate change, projections are highly uncertain and to sidestep this intractable uncertainty, adaptation efforts should improve societal ability to anticipate and mitigate individual events. Anticipation of climate-related events is made possible by seasonal climate forecasting, from which warnings of anomalous seasonal average temperature and rainfall, months in advance are possible. Seasonal climate hindcasts have been used to drive climate-based models for malaria, showing significant skill for observed malaria incidence. However, the relationship between seasonal average climate and malaria risk remains unquantified. Here we explore this relationship, using a dynamic weather-driven malaria model. We also quantify key uncertainty in the malaria model, by introducing variability in one of the first order uncertainties in model formulation. Results are visualized as location-specific impact surfaces: easily integrated with ensemble seasonal climate forecasts, and intuitively communicating quantified uncertainty. Methods are demonstrated for two epidemic regions, and are not limited to malaria modeling; the visualization method could be applied to any climate impact. PMID:25449318

  3. Cost effective malaria risk control using remote sensing and environmental data

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

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

  4. Transmission Risk from Imported Plasmodium vivax Malaria in the China-Myanmar Border Region.

    PubMed

    Wang, Duoquan; Li, Shengguo; Cheng, Zhibin; Xiao, Ning; Cotter, Chris; Hwang, Jimee; Li, Xishang; Yin, Shouqin; Wang, Jiazhi; Bai, Liang; Zheng, Zhi; Wang, Sibao

    2015-10-01

    Malaria importation and local vector susceptibility to imported Plasmodium vivax infection are a continuing risk along the China-Myanmar border. Malaria transmission has been prevented in 3 border villages in Tengchong County, Yunnan Province, China, by use of active fever surveillance, integrated vector control measures, and intensified surveillance and response.

  5. [Malaria in Morocco: from pre-elimination to elimination, what risks for the future?].

    PubMed

    Trari, B; Carnevale, P

    2011-10-01

    By basing itself essentially on the data of literature, this work redraw the historic periods of malaria in Morocco since 1912 at this day. The analysis of entomological, historic and current epidemiological situations of malaria in the Maghreb countries allows to identify elements of reflection on the risk in Morocco.

  6. Malaria Hyperendemicity and Risk for Artemisinin Resistance among Illegal Gold Miners, French Guiana.

    PubMed

    Pommier de Santi, Vincent; Djossou, Félix; Barthes, Nicolas; Bogreau, Hervé; Hyvert, Georges; Nguyen, Christophe; Pelleau, Stéphane; Legrand, Eric; Musset, Lise; Nacher, Mathieu; Briolant, Sébastien

    2016-05-01

    To assess the prevalence of malaria among illegal gold miners in the French Guiana rainforest, we screened 205 miners during May-June 2014. Malaria prevalence was 48.3%; 48.5% of cases were asymptomatic. Patients reported self-medication with artemisinin-based combination therapy. Risk for emergence and spread of artemisinin resistance among gold miners in the rainforest is high.

  7. Predictive Malaria Risk and Uncertainty Mapping in Nchelenge District, Zambia: Evidence of Widespread, Persistent Risk and Implications for Targeted Interventions

    PubMed Central

    Pinchoff, Jessie; Chaponda, Mike; Shields, Timothy; Lupiya, James; Kobayashi, Tamaki; Mulenga, Modest; Moss, William J.; Curriero, Frank C.

    2015-01-01

    Malaria risk maps may be used to guide policy decisions on whether vector control interventions should be targeted and, if so, where. Active surveillance for malaria was conducted through household surveys in Nchelenge District, Zambia from April 2012 through December 2014. Households were enumerated based on satellite imagery and randomly selected for study enrollment. At each visit, participants were administered a questionnaire and a malaria rapid diagnostic test (RDT). Logistic regression models were used to construct spatial prediction risk maps and maps of risk uncertainty. A total of 461 households were visited, comprising 1,725 participants, of whom 48% were RDT positive. Several environmental features were associated with increased household malaria risk in a multivariable logistic regression model adjusting for seasonal variation. The model was validated using both internal and external evaluation measures to generate and assess root mean square error, as well as sensitivity and specificity for predicted risk. The final, validated model was used to predict and map malaria risk including a measure of risk uncertainty. Malaria risk in a high, perennial transmission setting is widespread but heterogeneous at a local scale, with seasonal variation. Targeting malaria control interventions may not be appropriate in this epidemiological setting. PMID:26416106

  8. Predictive Malaria Risk and Uncertainty Mapping in Nchelenge District, Zambia: Evidence of Widespread, Persistent Risk and Implications for Targeted Interventions.

    PubMed

    Pinchoff, Jessie; Chaponda, Mike; Shields, Timothy; Lupiya, James; Kobayashi, Tamaki; Mulenga, Modest; Moss, William J; Curriero, Frank C

    2015-12-01

    Malaria risk maps may be used to guide policy decisions on whether vector control interventions should be targeted and, if so, where. Active surveillance for malaria was conducted through household surveys in Nchelenge District, Zambia from April 2012 through December 2014. Households were enumerated based on satellite imagery and randomly selected for study enrollment. At each visit, participants were administered a questionnaire and a malaria rapid diagnostic test (RDT). Logistic regression models were used to construct spatial prediction risk maps and maps of risk uncertainty. A total of 461 households were visited, comprising 1,725 participants, of whom 48% were RDT positive. Several environmental features were associated with increased household malaria risk in a multivariable logistic regression model adjusting for seasonal variation. The model was validated using both internal and external evaluation measures to generate and assess root mean square error, as well as sensitivity and specificity for predicted risk. The final, validated model was used to predict and map malaria risk including a measure of risk uncertainty. Malaria risk in a high, perennial transmission setting is widespread but heterogeneous at a local scale, with seasonal variation. Targeting malaria control interventions may not be appropriate in this epidemiological setting. © The American Society of Tropical Medicine and Hygiene.

  9. The impact of endemic and epidemic malaria on the risk of stillbirth in two areas of Tanzania with different malaria transmission patterns.

    PubMed

    Wort, Ulrika Uddenfeldt; Hastings, Ian; Mutabingwa, T K; Brabin, Bernard J

    2006-10-17

    The impact of malaria on the risk of stillbirth is still under debate. The aim of the present analysis was to determine comparative changes in stillbirth prevalence between two areas of Tanzania with different malaria transmission patterns in order to estimate the malaria attributable component. A retrospective analysis was completed of stillbirth differences between primigravidae and multigravidae in relation to malaria cases and transmission patterns for two different areas of Tanzania with a focus on the effects of the El Niño southern climatic oscillation (ENSO). One area, Kagera, experiences outbreaks of malaria, and the other area, Morogoro, is holoendemic. Delivery and malaria data were collected over a six year period from records of the two district hospitals in these locations. There was a significantly higher prevalence of low birthweight in primigravidae compared to multigravidae for both data sets. Low birthweight and stillbirth prevalence (17.5% and 4.8%) were significantly higher in Kilosa compared to Ndolage (11.9% and 2.4%). There was a significant difference in stillbirth prevalence between Ndolage and Kilosa between malaria seasons (2.4% and 5.6% respectively, p < 0.001) and during malaria seasons (1.9% and 5.9% respectively, p < 0.001). During ENSO there was no difference (4.1% and 4.9%, respectively). There was a significant difference in low birthweight prevalence between Ndolage and Kilosa between malaria seasons (14.4% and 23.0% respectively, p < 0.001) and in relation to malaria seasons (13.9% and 25.2% respectively, p < 0.001). During ENSO there was no difference (22.2% and 19.8%, respectively). Increased low birthweight risk occurred approximately five months following peak malaria prevalence, but stillbirth risk increased at the time of malaria peaks. Malaria exposure during pregnancy has a delayed effect on birthweight outcomes, but a more acute effect on stillbirth risk.

  10. The impact of endemic and epidemic malaria on the risk of stillbirth in two areas of Tanzania with different malaria transmission patterns

    PubMed Central

    Wort, Ulrika Uddenfeldt; Hastings, Ian; Mutabingwa, TK; Brabin, Bernard J

    2006-01-01

    Background The impact of malaria on the risk of stillbirth is still under debate. The aim of the present analysis was to determine comparative changes in stillbirth prevalence between two areas of Tanzania with different malaria transmission patterns in order to estimate the malaria attributable component. Methods A retrospective analysis was completed of stillbirth differences between primigravidae and multigravidae in relation to malaria cases and transmission patterns for two different areas of Tanzania with a focus on the effects of the El Niño southern climatic oscillation (ENSO). One area, Kagera, experiences outbreaks of malaria, and the other area, Morogoro, is holoendemic. Delivery and malaria data were collected over a six year period from records of the two district hospitals in these locations. Results There was a significantly higher prevalence of low birthweight in primigravidae compared to multigravidae for both data sets. Low birthweight and stillbirth prevalence (17.5% and 4.8%) were significantly higher in Kilosa compared to Ndolage (11.9% and 2.4%). There was a significant difference in stillbirth prevalence between Ndolage and Kilosa between malaria seasons (2.4% and 5.6% respectively, p < 0.001) and during malaria seasons (1.9% and 5.9% respectively, p < 0.001). During ENSO there was no difference (4.1% and 4.9%, respectively). There was a significant difference in low birthweight prevalence between Ndolage and Kilosa between malaria seasons (14.4% and 23.0% respectively, p < 0.001) and in relation to malaria seasons (13.9% and 25.2% respectively, p < 0.001). During ENSO there was no difference (22.2% and 19.8%, respectively). Increased low birthweight risk occurred approximately five months following peak malaria prevalence, but stillbirth risk increased at the time of malaria peaks. Conclusion Malaria exposure during pregnancy has a delayed effect on birthweight outcomes, but a more acute effect on stillbirth risk. PMID:17044915

  11. Climate change and malaria risk in the European part of Russia in 21st century

    NASA Astrophysics Data System (ADS)

    Shartova, N.; Malkhazova, S.

    2009-04-01

    The purpose of this research is development of prognostic model of malaria risk for European part of Russia (EPR) in the 21st century according to climate scenario IPCC "A2". The following issues have been formulated to reach the goal of the research: define the basic epidemiological parameters describing malaria situation and methods of data processing; creating of maps of malaria risk; analysis of changes in malaria distribution for predictable future climate conditions in comparison with conditions of a modern climate. A lot of reasons (biological, social and economic) impact on malaria distribution. Nevertheless, incubation period of the parasite first of all depends on temperature. This is a primary factor that defines a potential area of infection, ability and specificity to transmit malaria. According to this, the model is based on the relationship between climate (average daily temperature) and the intensity of malaria transmission. The object of research is malaria parasite Plasmodium vivax, which has for Russia (particularly for EPR) the greatest importance because it has the lowest minimal temperature threshold for development. Climate data is presented by daily average temperatures of air for three analyzed periods. 1961 -1989 describes a modern climate and corresponds to the minimum 30-year period that is necessary for an assessment of climate and changes connected with biotic components. Prognostic malaria model is based on predicted daily average temperatures for 2046-2065 (the middle of century) and 2089-2100 (the end of century). All data sets for EPR are presented in the grid 2x2. The conclusion on possible changes in malaria distribution and transmission in the middle and the end of the 21st century: There is going to be the increase of duration of effective temperatures period (period when parasite development is possible), period of effective susceptibility to infection of mosquitoes (period when malaria transmission cycle is possible); shift

  12. Challenges for modelling spatio-temporal variations of malaria risk in Malawi

    NASA Astrophysics Data System (ADS)

    Lowe, R.; Chirombo, J.; Tompkins, A. M.

    2012-04-01

    Malaria is the leading cause of morbidity and mortality in Malawi with more than 6 million episodes reported each year. Malaria poses a huge economic burden to Malawi in terms of the direct cost of treating malaria patients and also indirect costs resulting from workdays lost in agriculture and industry and absenteeism from school. Malawi implements malaria control activities within the Roll Back Malaria framework, with the objective to provide those most at risk (i.e. children under five years, pregnant woman and individuals with suppressed immune systems) access to personal and community protective measures. However, at present there is no mechanism by which to target the most 'at risk' populations ahead of an impending epidemic. Malaria transmission is influenced by variations in meteorological conditions, which impact the biology of the mosquito and the availability of breeding sites, but also socio-economic conditions such as levels of urbanisation, poverty and education, which influence human vulnerability and vector habitat. The many potential drivers of malaria, both extrinsic, such as climate, and intrinsic, such as population immunity are often difficult to disentangle. This presents a challenge for modelling of malaria risk in space and time. Using an age-stratified spatio-temporal dataset of malaria cases at the district level from July 2004 - June 2011, we use a spatio-temporal modelling framework to model variations in malaria risk in Malawi. Climatic and topographic variations are accounted for using an interpolation method to relate gridded products to administrative districts. District level data is tested in the model to account for confounding factors, including the proportion of the population living in urban areas; residing in traditional housing; with no toilet facilities; who do not attend school, etc, the number of health facilities per population and yearly estimates of insecticide-treated mosquito net distribution. In order to account for

  13. Ranking initial environmental and human health risk resulting from environmentally relevant nanomaterials.

    PubMed

    O'Brien, Niall; Cummins, Enda

    2010-01-01

    As nanomaterials find increased application in commercial and industrial products and processes so too the potential for release of these novel materials into the environment increases. The characteristics of these materials also may result in novel toxicological actions related to their nanoscale, which will have implications on their ecotoxicological and toxicological limits of exposure and eventual regulation. A framework for nanomaterial risk assessment on regulatory, ecotoxicological and toxicological bases developed from recent exposure and toxicity studies is presented. The release of nanoscale TiO(2), Ag and CeO(2) to the atmosphere and surface waters is assessed against provisional toxicological bench mark doses (BMDs) and critical effect doses (CEDs) developed from best available data. Predicted levels of nanomaterial release to surface waters and the atmosphere resulted in regulatory risk rankings of moderate concern based on worst case provisional regulatory limits. Inhalation and ingestion risk rankings were of very low concern based on the provisional inhalation and ingestion toxicity BMDLs and CEDLs determined for the nanomaterials in question. More toxicological data is needed on nanoscale CeO(2) inhalation to develop a true dose response as in vitro cytotoxicity studies yielded an inhalation risk ranking of lower concern. The moderate to high ecotoxicological risk rankings posed by the release of nanoscale TiO(2) and Ag to surface waters highlights the need for guidance and restriction on the usage and disposal of commercial products containing nanomaterial. The risk rankings presented in this assessment give a first indication of the relative risks posed by the usage and release of these materials into the environment and indicate what materials require further investigation into their nano-specific toxicological actions. As more nano-relevant toxicity studies are published, end-points and risk levels related to nano-specific toxicity actions may

  14. Climate change and malaria risk in Russia in 21st century

    NASA Astrophysics Data System (ADS)

    Malkhazova, S.; Shartova, N.

    2010-09-01

    The purpose of this research is development of prognostic model of malaria risk for Russia in the 21st century according to climate scenario IPCC "А2". The following issues have been formulated to reach the goal of the research: - define the basic epidemiological parameters describing malaria situation and methods of data processing; - creating of maps of malaria risk; - analysis of changes in malaria distribution for predictable future climate conditions in comparison with conditions of a modern climate. A lot of reasons (biological, social and economic) impact on malaria distribution. Nevertheless, incubation period of the parasite first of all depends on temperature. This is a primary factor that defines a potential area of infection, ability and specificity to transmit malaria. According to this, the model is based on the relationship between climate (average daily temperature) and the intensity of malaria transmission. The object of research is malaria parasite Plasmodium vivax, which has for Russia the greatest importance because it has the lowest minimal temperature threshold for development. Climate data is presented by daily average temperatures of air for three analyzed periods. 1961 -1989 describes a modern climate and corresponds to the minimum 30-year period that is necessary for an assessment of climate and changes connected with biotic components. Prognostic malaria model is based on predicted daily average temperatures for 2046-2065 (the middle of century) and 2089-2100 (the end of century). All data sets are presented in the grid 2х20. The conclusion on possible changes in malaria distribution and transmission in the middle and the end of the 21st century: There is going to be the increase of duration of effective temperatures period (period when parasite development is possible), period of effective susceptibility to infection of mosquitoes (period when malaria transmission cycle is possible); shift of the beginning of malaria transmission

  15. Epidemiology and Risk Analysis of Malaria among Pregnant Women

    PubMed Central

    Dhiman, S; Yadav, K; Goswami, D; Das, NG; Baruah, I; Singh, L

    2012-01-01

    Malaria remains a complex problem during the pregnancy, which threatens > 35 millions pregnant women every year. Malaria pathogenesis in pregnancy results in accumulation of infected RBCs in the intervillous spaces causing severe alterations leading to the reduced materno-foetal exchanges. In this article we have revisited the current evidences of clinical implications and overall burden of malaria in pregnancy. Many adverse aftermaths including, low birth weight, intrauterine growth retardation, preterm delivery, stillbirth and anemia were found associated with malaria in pregnant women. Despite of worldwide comprehensive control programmes for malaria in pregnancy, the disease control has been a daunting task everywhere. Socio cultural, economical, lack of awareness and various logistic problems compound the disease in developing countries. Thorough evidence based information and estimates, education and awareness and strengthening of prevention programmes are needed urgently to achieve success in malaria control in pregnancy. PMID:23113116

  16. What is a resistance gene? Ranking risk in resistomes.

    PubMed

    Martínez, José L; Coque, Teresa M; Baquero, Fernando

    2015-02-01

    Metagenomic studies have shown that antibiotic resistance genes are ubiquitous in the environment, which has led to the suggestion that there is a high risk that these genes will spread to bacteria that cause human infections. If this is true, estimating the real risk of dissemination of resistance genes from environmental reservoirs to human pathogens is therefore very difficult. In this Opinion article, we analyse the current definitions of antibiotic resistance and antibiotic resistance genes, and we describe the bottlenecks that affect the transfer of antibiotic resistance genes to human pathogens. We propose rules for estimating the risks associated with genes that are present in environmental resistomes by evaluating the likelihood of their introduction into human pathogens, and the consequences of such events for the treatment of infections.

  17. Ikonos-derived malaria transmission risk in northwestern Thailand.

    PubMed

    Sithiprasasna, Ratana; Ugsang, Donald M; Honda, Kiyoshi; Jones, James W; Singhasivanon, Pratap

    2005-01-01

    We mapped overall malaria cases and located each field observed major malaria vector breeding habitat using Global Positioning System (GPS) instruments from September 2000 to October 2003 around the three malaria-endemic villages of Ban Khun Huay, Ban Pa Dae, and Ban Tham Seau, Mae Sod district, Tak Province, Thailand. The land-use/land-cover classifications of the three villages and surrounding areas were performed on IKONOS satellite images acquired on 12 November 2001 with a spatial resolution of 1 x 1 m. Stream network was delineated and displayed. Proximity analysis was performed on the locations of the houses with and without malaria cases within a 1.5 km buffer from An. minimus immature mosquito breeding habitats, mainly stream margins. The 1.5 km used in our proximity analysis was arbitrarily estimated based on the An. minimus flight range. A statistical t-test at 5% significance level was performed to evaluate whether houses with malaria cases have higher proximities to streams than houses without malaria cases. The result shows no significant difference between proximity to streams between houses with malaria cases and houses without malaria cases. We suspect that the actual flight range of An. minimus may be greater than 1.5 km. The An. minimus larval habitat deserves more detailed investigation. Further studies on human behavior contrary to that required for adequate malaria control among these three villages are also recommended.

  18. Knowledge, attitudes and practices of business travelers regarding malaria risk and prevention.

    PubMed

    Weber, Roger; Schlagenhauf, Patricia; Amsler, Lorenz; Steffen, Robert

    2003-01-01

    This study aimed to determine the knowledge, attitudes and practices of Swiss business travelers with regard to malaria. Questionnaires printed in three languages were distributed by employers, travel agencies and tropical medicine specialists to business travelers with destinations in malaria endemic countries. In total, 401 questionnaires were evaluated. Thirty-three percent visited high-risk areas, 27% visited low-risk areas, and 40% visited only malaria-free areas within endemic countries. Among the investigated business travelers, 6% had experienced malaria infection, and 29% had previously had blood smears tested for malaria at least once. Almost all business travelers, 95%, knew that mosquitoes are the main vectors of malaria. The infection risk between dusk and dawn was known to 71%, and the incubation time to 36%. Apart from fever (99%) and headache (63%), other malaria symptoms were known to only 13% to 36% of the travelers. If signs of illness such as fever and headache occurred, 63% would react adequately and seek medical advice within 24 h. Only 16% of the travelers to African high-risk areas followed the recommended behavior concerning anti-mosquito and antimalarial strategies; 31% of those on trips to low-risk areas used an adequate protective strategy. Of the business travelers using chemoprophylaxis during travel, just 50% continued intake post travel, as requested, after leaving the endemic area. Business travelers are well informed regarding the mode of transmission and the risk of malaria at specific destinations but tend to comply poorly with anti-mosquito and chemoprophylactic strategies. The knowledge, attitudes and practices of business travelers with regard to malaria prevention need to be improved.

  19. Factors associated with risk of malaria infection among pregnant women in Lagos, Nigeria

    PubMed Central

    2013-01-01

    Background Pregnant women living in an area of stable malaria transmission such as Lagos, Nigeria, have been identified as being at an increased risk of the effects of malaria infection. In this area, most of the infections are asymptomatic which means they are overlooked and untreated much to the detriment of the mother and her foetus. The reality of scaled-up malaria interventions with long-lasting insecticide treated nets, vector control, artemisinin combination therapy (ACT) and intermittent preventive treatment of malaria pregnancy (IPTp) using sulphadoxine pyrimethamine (SP) is that it is also essential to determine the risk factors at play in these kinds of circumstances. This study was aimed at identifying the factors associated with risk of malaria infection in pregnant women in Lagos, Southwest Nigeria. Methods Demographic information and malaria prevention practices of the pregnant women studied were captured using structured questionnaire. Microscopy was used to establish malaria infection, species identification and parasite density. Relative risk and multivariate logistic regression analysis were used to compare factors associated with malaria in pregnant women. Results Malaria microscopy details, demographic information and malaria prevention practices of the pregnant women were obtained using a structured questionnaire. The prevalence of malaria using peripheral blood from 1,084 pregnant women that participated in the study was 7.7%. Plasmodium falciparum (P. falciparum) was seen in 95.2% of the cases as either mixed infection with P. malariae (3.6%) or as a mono infection (91.6%). Malaria preventive practices associated with a significant reduction (P<0.05) in the malaria infection was the use of insecticide sprays (RR = 0.36, 95 C.I. 0.24-0.54), and the combined use of insecticide spray and insecticide-treated nets (ITN) (RR= 6.53, 95% C.I. 0.92-46.33). Sleeping under ITN alone (RR = 1.07, 95% C.I. 0.55-2.09) was not associated with significant

  20. Mapping Risk of Malaria Transmission in Mainland Portugal Using a Mathematical Modelling Approach

    PubMed Central

    Capinha, César; Rocha, Jorge; Sousa, Carla

    2016-01-01

    Malaria is currently one of the world´s major health problems. About a half-million deaths are recorded every year. In Portugal, malaria cases were significantly high until the end of the 1950s but the disease was considered eliminated in 1973. In the past few years, endemic malaria cases have been recorded in some European countries. With the increasing human mobility from countries with endemic malaria to Portugal, there is concern about the resurgence of this disease in the country. Here, we model and map the risk of malaria transmission for mainland Portugal, considering 3 different scenarios of existing imported infections. This risk assessment resulted from entomological studies on An. atroparvus, the only known mosquito capable of transmitting malaria in the study area. We used the malariogenic potential (determined by receptivity, infectivity and vulnerability) applied over geospatial data sets to estimate spatial variation in malaria risk. The results suggest that the risk exists, and the hotspots are concentrated in the northeast region of the country and in the upper and lower Alentejo regions. PMID:27814371

  1. Mapping Risk of Malaria Transmission in Mainland Portugal Using a Mathematical Modelling Approach.

    PubMed

    Gomes, Eduardo; Capinha, César; Rocha, Jorge; Sousa, Carla

    2016-01-01

    Malaria is currently one of the world´s major health problems. About a half-million deaths are recorded every year. In Portugal, malaria cases were significantly high until the end of the 1950s but the disease was considered eliminated in 1973. In the past few years, endemic malaria cases have been recorded in some European countries. With the increasing human mobility from countries with endemic malaria to Portugal, there is concern about the resurgence of this disease in the country. Here, we model and map the risk of malaria transmission for mainland Portugal, considering 3 different scenarios of existing imported infections. This risk assessment resulted from entomological studies on An. atroparvus, the only known mosquito capable of transmitting malaria in the study area. We used the malariogenic potential (determined by receptivity, infectivity and vulnerability) applied over geospatial data sets to estimate spatial variation in malaria risk. The results suggest that the risk exists, and the hotspots are concentrated in the northeast region of the country and in the upper and lower Alentejo regions.

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

    PubMed

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

    2010-10-23

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

  3. High Iron Stores in the Low Malaria Season Increase Malaria Risk in the High Transmission Season in a Prospective Cohort of Rural Zambian Children.

    PubMed

    Barffour, Maxwell A; Schulze, Kerry J; Coles, Christian L; Chileshe, Justin; Kalungwana, Ng'andwe; Arguello, Margia; Siamusantu, Ward; Moss, William J; West, Keith P; Palmer, Amanda C

    2017-08-01

    Background: Higher iron stores, defined by serum ferritin (SF) concentration, may increase malaria risk.Objective: We evaluated the association between SF assessed during low malaria season and the risk of malaria during high malaria season, controlling for inflammation.Methods: Data for this prospective study were collected from children aged 4-8 y (n = 745) participating in a biofortified maize efficacy trial in rural Zambia. All malaria cases were treated at baseline (September 2012). We used baseline SF and malaria status indicated by positive microscopy at endline (March 2013) to define exposure and outcome, respectively. Iron status was defined as deficient (corrected or uncorrected SF <12 or <15 μg/L, depending on age <5 or ≥5 y, respectively), moderate (<75 μg/L, excluding deficient), or high (≥75 μg/L). We used a modified Poisson regression to model the risk of malaria in the high transmission seasons (endline) as a function of iron status assessed in the low malaria seasons (baseline).Results: We observed an age-dependent, positive dose-response association between ferritin in the low malaria season and malaria incidence during the high malaria season in younger children. In children aged <6 y (but not older children), we observed a relative increase in malaria risk in the moderate iron status [incidence rate ratio (IRR) with SF: 1.56; 95% CI: 0.64, 3.86; IRR with inflammation-corrected SF: 1.92; 95% CI: 0.75, 4.93] and high iron status (IRR with SF: 2.66; 95% CI: 1.10, 6.43; or IRR with corrected SF: 2.93; 95% CI: 1.17, 7.33) categories compared with the deficient iron status category. The relative increase in malaria risk for children with high iron status was statistically significant only among those with a concurrently normal serum soluble transferrin receptor concentration (<8.3 mg/L; IRR: 1.97; 95% CI: 1.20, 7.37).Conclusions: Iron adequacy in 4- to 8-y-old children in rural Zambia was associated with increased malaria risk. Our findings

  4. 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

    Background Despite Vietnam's success in reducing malaria mortality and morbidity over the last decade, malaria persists in the forested and mountainous areas of the central and southern provinces, where more than 50% of the clinical cases and 90% of severe cases and malaria deaths occur. Methods Between July 2005 and September 2006, a multi-method study, triangulating a malariometric cross-sectional survey and qualitative data from focused ethnography, was carried out among the Ra-glai ethnic minority in the hilly forested areas of south-central Vietnam. Results Despite the relatively high malaria burden among the Ra-glai and their general awareness that mosquitoes can transmit an unspecific kind of fever (84.2%), the use of bed nets, distributed free of charge by the national malaria control programme, remains low at the farmers' forest fields where the malaria risk is the highest. However, to meet work requirements during the labour intensive malaria transmission and rainy season, Ra-glai farmers combine living in government supported villages along the road with a second home or shelter at their slash and burn fields located in the forest. Bed net use was 84.6% in the villages but only 52.9% at the forest fields; 20.6% of the respondents slept unprotected in both places. Such low use may be explained by the low perception of the risk for malaria, decreasing the perceived need to sleep protected. Several reasons may account for this: (1) only 15.6% acknowledged the higher risk of contracting malaria in the forest than in the village; (2) perceived mosquito biting times only partially coincided with Anopheles dirus ss and Anopheles minimus A true biting times; (3) the disease locally identified as 'malaria' was hardly perceived as having an impact on forest farmers' daily lives as they were unaware of the specific kind of fevers from which they had suffered even after being diagnosed with malaria at the health centre (20.9%). Conclusions The progressive

  5. Estimating the malaria risk of African mosquito movement by air travel

    PubMed Central

    Tatem, Andrew J; Rogers, David J; Hay, Simon I

    2006-01-01

    Background The expansion of global travel has resulted in the importation of African Anopheles mosquitoes, giving rise to cases of local malaria transmission. Here, cases of 'airport malaria' are used to quantify, using a combination of global climate and air traffic volume, where and when are the greatest risks of a Plasmodium falciparum-carrying mosquito being importated by air. This prioritises areas at risk of further airport malaria and possible importation or reemergence of the disease. Methods Monthly data on climate at the World's major airports were combined with air traffic information and African malaria seasonality maps to identify, month-by-month, those existing and future air routes at greatest risk of African malaria-carrying mosquito importation and temporary establishment. Results The location and timing of recorded airport malaria cases proved predictable using a combination of climate and air traffic data. Extending the analysis beyond the current air network architecture enabled identification of the airports and months with greatest climatic similarity to P. falciparum endemic regions of Africa within their principal transmission seasons, and therefore at risk should new aviation routes become operational. Conclusion With the growth of long haul air travel from Africa, the identification of the seasonality and routes of mosquito importation is important in guiding effective aircraft disinsection and vector control. The recent and continued addition of air routes from Africa to more climatically similar regions than Europe will increase movement risks. The approach outlined here is capable of identifying when and where these risks are greatest. PMID:16842613

  6. Environmental factors and population at risk of malaria in Nkomazi municipality, South Africa.

    PubMed

    Adeola, A M; Botai, O J; Olwoch, J M; Rautenbach, C J de W; Adisa, O M; Taiwo, O J; Kalumba, A M

    2016-05-01

    Nkomazi local municipality of South Africa is a high-risk malaria region with an incidence rate of about 500 cases per 100 000. We examined the influence of environmental factors on population (age group) at risk of malaria. r software was used to statistically analyse data. Using remote sensing technology, a Landsat 8 image of 4th October 2015 was classified using object-based classification and a 5-m resolution. Spot height data were used to generate a digital elevation model of the area. A total of 60 718 malaria cases were notified across 48 health facilities in Nkomazi municipality between January 1997 and August 2015. Malaria incidence was highly associated with irrigated land (P = 0.001), water body (P = 0.011) and altitude ≤400 m (P = 0.001). The multivariate model showed that with 10% increase in the extent of irrigated areas, malaria risk increased by almost 39% in the entire study area and by almost 44% in the 2-km buffer zone of selected villages. Malaria incidence is more pronounced in the economically active population aged 15-64 and in males. Both incidence and case fatality rate drastically declined over the study period. A predictive model based on environmental factors would be useful in the effort towards malaria elimination by fostering appropriate targeting of control measures and allocating of resources. © 2016 John Wiley & Sons Ltd.

  7. Spatial Variability in Toxicity Indicators Used to Rank Chemical Risks

    PubMed Central

    Cutter, Susan L.; Scott, Michael S.; Hill, Arleen A.

    2002-01-01

    Objectives. This study used 6 different measures of toxicity to explore spatial and statistical variations in relative risk indicators of Toxic Release Inventory emissions. Methods. Statistical and spatial correlations between the 6 indices were computed for individual South Carolina facilities. Results. Although the 6 toxicity indices are not highly correlated in theory, they have more commonality in practice. There was significant spatial variation in the indices by individual facility level. Conclusions. Environmental justice researchers must be cognizant of differences in toxicity indices because the choice of the toxicity measure can alter (statistically and spatially) the results of equity analyses and lead to erroneous conclusions. (Am J Public Health. 2002;92:420-422) PMID:11867323

  8. Critical review of methods for risk ranking of food related hazards, based on risks for human health.

    PubMed

    van der Fels-Klerx, H J; van Asselt, E D; Raley, M; Poulsen, M; Korsgaard, H; Bredsdorff, L; Nauta, M; D'Agostino, M; Coles, D; Marvin, H J P; Frewer, L J

    2016-02-08

    This study aimed to critically review methods for ranking risks related to food safety and dietary hazards on the basis of their anticipated human health impacts. A literature review was performed to identify and characterize methods for risk ranking from the fields of food, environmental science and socio-economic sciences. The review used a predefined search protocol, and covered the bibliographic databases Scopus, CAB Abstracts, Web of Sciences, and PubMed over the period 1993-2013. All references deemed relevant, on the basis of of predefined evaluation criteria, were included in the review, and the risk ranking method characterized. The methods were then clustered - based on their characteristics - into eleven method categories. These categories included: risk assessment, comparative risk assessment, risk ratio method, scoring method, cost of illness, health adjusted life years, multi-criteria decision analysis, risk matrix, flow charts/decision trees, stated preference techniques and expert synthesis. Method categories were described by their characteristics, weaknesses and strengths, data resources, and fields of applications. It was concluded there is no single best method for risk ranking. The method to be used should be selected on the basis of risk manager/assessor requirements, data availability, and the characteristics of the method. Recommendations for future use and application are provided.

  9. The risk of malaria in Ghanaian infants born to women managed in pregnancy with intermittent screening and treatment for malaria or intermittent preventive treatment with sulfadoxine/pyrimethamine.

    PubMed

    Awine, Timothy; Belko, Mark M; Oduro, Abraham R; Oyakhirome, Sunny; Tagbor, Harry; Chandramohan, Daniel; Milligan, Paul; Cairns, Matthew; Greenwood, Brian; Williams, John E

    2016-01-28

    Several studies have reported an association between malaria infection of the placenta and the risk of malaria in young children in the first year of life, but it is not known if this is causal, or influenced by malaria control measures during pregnancy. This paper compares the incidence of malaria in infants born to mothers who received either intermittent preventive treatment with sulfadoxine/pyrimethamine (IPTp-SP) or screening with a rapid diagnostic test and treatment with artemether-lumefantrine (ISTp-AL) during their pregnancy. From July 2011 to April 2013, 988 infants of women enrolled in a trial of IPTp-SP versus ISTp-AL in the Kassena-Nankana districts of northern Ghana were followed to determine the risk of clinical malaria during early life, and their risk of parasitaemia and anaemia at 6 and 12 months of age. In addition, the incidence of clinical malaria in infants whose mothers had malaria infection of the placenta was compared with that in infants born to women free of placental malaria. The incidence of clinical malaria was 0.237 and 0.211 episodes per child year in infants whose mothers had received ISTp-AL or IPTp-SP, respectively. The adjusted incidence rate ratio and the adjusted rate difference were 0.94 (95% CI 0.68, 1.33) and 0.029 (95% CI -0.053, 0.110) cases per child year at risk respectively. The incidence of clinical malaria was similar in infants born to women with placental malaria (0.195 episodes per child year) and in infants of women without placental malaria (0.224 episodes per child year) (rate ratio = 0.86 [95% CI 0.54, 1.37]). Infants born to women managed with ISTp-AL during pregnancy were not at greatly increased risk of malaria compared with infants born to women who had received IPTp-SP. The incidence of malaria in infants was similar whether or not their mother had had placental malaria.

  10. A cross-sectional analysis of traditional medicine use for malaria alongside free antimalarial drugs treatment amongst adults in high-risk malaria endemic provinces of Indonesia

    PubMed Central

    Suswardany, Dwi Linna; Sibbritt, David W.; Supardi, Sudibyo; Pardosi, Jerico F.; Chang, Sungwon; Adams, Jon

    2017-01-01

    Background The level of traditional medicine use, particularly Jamu use, in Indonesia is substantial. Indonesians do not always seek timely treatment for malaria and may seek self-medication via traditional medicine. This paper reports findings from the first focused analyses of traditional medicine use for malaria in Indonesia and the first such analyses worldwide to draw upon a large sample of respondents across high-risk malaria endemic areas. Methods A sub-study of the Indonesia Basic Health Research/Riskesdas Study 2010 focused on 12,226 adults aged 15 years and above residing in high-risk malaria-endemic provinces. Logistic regression was undertaken to determine the significant associations for traditional medicine use for malaria symptoms. Findings Approximately one in five respondents use traditional medicine for malaria symptoms and the vast majority experiencing multiple episodes of malaria use traditional medicine alongside free antimalarial drug treatments. Respondents consuming traditional medicine for general health/common illness purposes every day (odds ratio: 3.75, 95% Confidence Interval: 2.93 4.79), those without a hospital in local vicinity (odds ratio: 1.31, 95% Confidence Interval: 1.10 1.57), and those living in poorer quality housing, were more likely to use traditional medicine for malaria symptoms. Conclusion A substantial percentage of those with malaria symptoms utilize traditional medicine for treating their malaria symptoms. In order to promote safe and effective malaria treatment, all providing malaria care in Indonesia need to enquire with their patients about possible traditional medicine use. PMID:28329019

  11. 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.

  12. Participatory Risk Mapping of Malaria Vector Exposure in Northern South America using Environmental and Population Data.

    PubMed

    Fuller, D O; Troyo, A; Alimi, T O; Beier, J C

    2014-03-01

    Malaria elimination remains a major public health challenge in many tropical regions, including large areas of northern South America. In this study, we present a new high spatial resolution (90 × 90 m) risk map for Colombia and surrounding areas based on environmental and human population data. The map was created through a participatory multi-criteria decision analysis in which expert opinion was solicited to determine key environmental and population risk factors, different fuzzy functions to standardize risk factor inputs, and variable factor weights to combine risk factors in a geographic information system. The new risk map was compared to a map of malaria cases in which cases were aggregated to the municipio (municipality) level. The relationship between mean municipio risk scores and total cases by muncípio showed a weak correlation. However, the relationship between pixel-level risk scores and vector occurrence points for two dominant vector species, Anopheles albimanus and An. darlingi, was significantly different (p < 0.05) from a random point distribution, as was a pooled point distribution for these two vector species and An. nuneztovari. Thus, we conclude that the new risk map derived based on expert opinion provides an accurate spatial representation of risk of potential vector exposure rather than malaria transmission as shown by the pattern of malaria cases, and therefore it may be used to inform public health authorities as to where vector control measures should be prioritized to limit human-vector contact in future malaria outbreaks.

  13. Participatory Risk Mapping of Malaria Vector Exposure in Northern South America using Environmental and Population Data

    PubMed Central

    Fuller, D.O.; Troyo, A.; Alimi, T.O.; Beier, J.C.

    2014-01-01

    Malaria elimination remains a major public health challenge in many tropical regions, including large areas of northern South America. In this study, we present a new high spatial resolution (90 × 90 m) risk map for Colombia and surrounding areas based on environmental and human population data. The map was created through a participatory multi-criteria decision analysis in which expert opinion was solicited to determine key environmental and population risk factors, different fuzzy functions to standardize risk factor inputs, and variable factor weights to combine risk factors in a geographic information system. The new risk map was compared to a map of malaria cases in which cases were aggregated to the municipio (municipality) level. The relationship between mean municipio risk scores and total cases by muncípio showed a weak correlation. However, the relationship between pixel-level risk scores and vector occurrence points for two dominant vector species, Anopheles albimanus and An. darlingi, was significantly different (p < 0.05) from a random point distribution, as was a pooled point distribution for these two vector species and An. nuneztovari. Thus, we conclude that the new risk map derived based on expert opinion provides an accurate spatial representation of risk of potential vector exposure rather than malaria transmission as shown by the pattern of malaria cases, and therefore it may be used to inform public health authorities as to where vector control measures should be prioritized to limit human-vector contact in future malaria outbreaks. PMID:24976656

  14. High-Resolution Plasmodium falciparum Malaria Risk Mapping in Mutasa District, Zimbabwe: Implications for Regaining Control.

    PubMed

    Kanyangarara, Mufaro; Mamini, Edmore; Mharakurwa, Sungano; Munyati, Shungu; Gwanzura, Lovemore; Kobayashi, Tamaki; Shields, Timothy; Mullany, Luke C; Mutambu, Susan; Mason, Peter R; Curriero, Frank C; Moss, William J

    2016-07-06

    In Zimbabwe, more than half of malaria cases are concentrated in Manicaland Province, where seasonal malaria epidemics occur despite intensified control strategies. The objectives of this study were to develop a prediction model based on environmental risk factors and obtain seasonal malaria risk maps for Mutasa District, one of the worst affected districts in Manicaland Province. From October 2012 to September 2015, 483 households were surveyed, and 104 individuals residing within 69 households had positive rapid diagnostic test results. Logistic regression was used to model the probability of household positivity as a function of the environmental covariates extracted from high-resolution remote sensing data sources. Model predictions and prediction standard errors were generated for the rainy and dry seasons. The resulting maps predicted elevated risk during the rainy season, particularly in low-lying areas bordering Mozambique. In contrast, the risk of malaria was low across the study area during the dry season with foci of malaria risk scattered along the northern and western peripheries of the study area. These findings underscore the need for strong cross-border malaria control initiatives to complement country-specific interventions. © The American Society of Tropical Medicine and Hygiene.

  15. Plasmodium knowlesi malaria: assessing the risk to the British Armed Forces.

    PubMed

    Roughton, S A; Green, A D

    2012-12-01

    Plasmodium knowlesi is a zoonosis and is now recognised as the fifth commonly occurring form of human malaria. It is endemic in South East Asia, including some areas previously declared malaria free or at low risk for malaria. The epidemiology of the disease is very different to other forms of malaria which are determined by transmission by anthrophilic mosquitoes from human reservoirs. In contrast Plasmodium knowlesi malaria has a monkey reservoir and disease is transmitted to humans by mosquitoes that normally feed on animals. People become accidentally infected when they enter the ranges of the vector mosquitoes and animal hosts. Improved and novel diagnostic methods have indicated that human disease is much more common than previously thought. Although the greatest disease burden falls on local populations living in endemic areas, visitors entering such zones are also at risk. The changing nature of tourism with deep jungle expeditions being more heavily marketed, and short visits to endemic zones now common, mean that new populations are increasingly recognised as being at risk. One such group are military personnel undergoing jungle training or deployed on Operations. The potential for severe disease in areas previously considered at low risk for malaria means that risk assessment needs to be reviewed, coupled with communication strategies to address prevention of a zoonotic form of the disease. The role of chemoprophylaxis in some specific groups may need to be considered.

  16. Fine-Scale Mapping by Spatial Risk Distribution Modeling for Regional Malaria Endemicity and Its Implications under the Low-to-Moderate Transmission Setting in Western Cambodia

    PubMed Central

    Okami, Suguru; Kohtake, Naohiko

    2016-01-01

    The disease burden of malaria has decreased as malaria elimination efforts progress. The mapping approach that uses spatial risk distribution modeling needs some adjustment and reinvestigation in accordance with situational changes. Here we applied a mathematical modeling approach for standardized morbidity ratio (SMR) calculated by annual parasite incidence using routinely aggregated surveillance reports, environmental data such as remote sensing data, and non-environmental anthropogenic data to create fine-scale spatial risk distribution maps of western Cambodia. Furthermore, we incorporated a combination of containment status indicators into the model to demonstrate spatial heterogeneities of the relationship between containment status and risks. The explanatory model was fitted to estimate the SMR of each area (adjusted Pearson correlation coefficient R2 = 0.774; Akaike information criterion AIC = 149.423). A Bayesian modeling framework was applied to estimate the uncertainty of the model and cross-scale predictions. Fine-scale maps were created by the spatial interpolation of estimated SMRs at each village. Compared with geocoded case data, corresponding predicted values showed conformity [Spearman’s rank correlation r = 0.662 in the inverse distance weighed interpolation and 0.645 in ordinal kriging (95% confidence intervals of 0.414–0.827 and 0.368–0.813, respectively), Welch’s t-test; Not significant]. The proposed approach successfully explained regional malaria risks and fine-scale risk maps were created under low-to-moderate malaria transmission settings where reinvestigations of existing risk modeling approaches were needed. Moreover, different representations of simulated outcomes of containment status indicators for respective areas provided useful insights for tailored interventional planning, considering regional malaria endemicity. PMID:27415623

  17. Ranking hospitals on surgical quality: does risk-adjustment always matter?

    PubMed

    Dimick, Justin B; Birkmeyer, John D

    2008-09-01

    It is a widely held belief that detailed risk-adjustment is always necessary in comparative reports of surgical performance. We sought to evaluate the importance of risk-adjustment for two cardiac surgery report cards in New York and Pennsylvania. We abstracted data directly from publicly available cardiac surgery report cards from New York State (2001 and 2002) and Pennsylvania (2000 and 2002). We first estimated the correlation between unadjusted and risk-adjusted mortality rates. We then divided hospitals into three groups of historic performance (best, average, and worst) for both unadjusted and risk-adjusted mortality rankings. We then calculated the risk-adjusted mortality within each of these groups using data from the report card from the subsequent year. Risk-adjusted and unadjusted mortality rates were highly correlated for both New York (Pearson's r=0.95; Spearman's r=0.91) and Pennsylvania (Pearson's r=0.87; Spearman's r=0.89). For both states, risk-adjusted and unadjusted rankings were equally good at predicting subsequent mortality. In New York State, mortality for hospitals in the worst group was 50% higher than that in the best group regardless of whether unadjusted (relative risk [RR], 1.51) or adjusted (RR, 1.49) rankings were used. The same was found in Pennsylvania, where the results for unadjusted (RR, 1.53) and adjusted (RR, 1.45) rankings were nearly identical. Based on data from two prominent state registries, risk-adjusted and unadjusted mortality rates provide nearly identical estimates of hospital performance with coronary artery bypass. Risk-adjustment may not always be important for identifying high quality hospitals.

  18. The design of hazard risk assessment matrices for ranking occupational health risks and their application in mining and minerals processing.

    PubMed

    Donoghue, A M

    2001-03-01

    Two hazard risk assessment matrices for the ranking of occupational health risks are described. The qualitative matrix uses qualitative measures of probability and consequence to determine risk assessment codes for hazard-disease combinations. A walk-through survey of an underground metalliferous mine and concentrator is used to demonstrate how the qualitative matrix can be applied to determine priorities for the control of occupational health hazards. The semi-quantitative matrix uses attributable risk as a quantitative measure of probability and uses qualitative measures of consequence. A practical application of this matrix is the determination of occupational health priorities using existing epidemiological studies. Calculated attributable risks from epidemiological studies of hazard-disease combinations in mining and minerals processing are used as examples. These historic response data do not reflect the risks associated with current exposures. A method using current exposure data, known exposure-response relationships and the semi-quantitative matrix is proposed for more accurate and current risk rankings.

  19. Malaria Hyperendemicity and Risk for Artemisinin Resistance among Illegal Gold Miners, French Guiana

    PubMed Central

    Pommier de Santi, Vincent; Djossou, Félix; Barthes, Nicolas; Bogreau, Hervé; Hyvert, Georges; Nguyen, Christophe; Pelleau, Stéphane; Legrand, Eric; Musset, Lise; Nacher, Mathieu

    2016-01-01

    To assess the prevalence of malaria among illegal gold miners in the French Guiana rainforest, we screened 205 miners during May–June 2014. Malaria prevalence was 48.3%; 48.5% of cases were asymptomatic. Patients reported self-medication with artemisinin-based combination therapy. Risk for emergence and spread of artemisinin resistance among gold miners in the rainforest is high. PMID:27089004

  20. Asthma and atopic dermatitis are associated with increased risk of clinical Plasmodium falciparum malaria

    PubMed Central

    Herrant, Magali; Loucoubar, Cheikh; Bassène, Hubert; Gonçalves, Bronner; Boufkhed, Sabah; Diene Sarr, Fatoumata; Fontanet, Arnaud; Tall, Adama; Baril, Laurence; Mercereau-Puijalon, Odile; Mécheri, Salaheddine; Sakuntabhai, Anavaj; Paul, Richard

    2013-01-01

    Objectives To assess the impact of atopy and allergy on the risk of clinical malaria. Design A clinical and immunological allergy cross-sectional survey in a birth cohort of 175 children from 1 month to 14 years of age followed for up to 15 years in a longitudinal open cohort study of malaria in Senegal. Malaria incidence data were available for 143 of these children (aged 4 months to 14 years of age) for up to 15 years. Mixed-model regression analysis was used to determine the impact of allergy status on malaria incidence, adjusting for age, gender, sickle-cell trait and force of infection. Main outcome measures Asthma, allergic rhinoconjunctivitis and atopic dermatitis status, the number of clinical Plasmodium falciparum malaria episodes since birth and associated parasite density. Results 12% of the children were classified as asthmatic and 10% as having atopic dermatitis. These groups had respectively a twofold (OR 2.12 95%; CI 1.46 to 3.08; p=8×10−5) and threefold (OR 3.15; 1.56 to 6.33; p=1.3×10−3) increase in the risk of clinical P falciparum malaria once older than the age of peak incidence of clinical malaria (3–4 years of age). They also presented with higher P falciparum parasite densities (asthma: mean 105.3 parasites/μL±SE 41.0 vs 51.3±9.7; p=6.2×10−3. Atopic dermatitis: 135.4±70.7 vs 52.3±11.0; p=0.014). There was no effect of allergy on the number of non-malaria clinical presentations. Individuals with allergic rhinoconjunctivitis did not have an increased risk of clinical malaria nor any difference in parasite densities. Conclusions These results demonstrate that asthma and atopic dermatitis delay the development of clinical immunity to P falciparum. Despite the encouraging decrease in malaria incidence rates in Africa, a significant concern is the extent to which the increase in allergy will exacerbate the burden of malaria. Given the demonstrated antiparasitic effect of antihistamines, administration to atopic

  1. Conflict in Neighboring Countries, a Great Risk for Malaria Elimination in Southwestern Iran: Narrative Review Article

    PubMed Central

    MOLAEE ZADEH, Maryam; SHAHANDEH, Khandan; BIGDELI, Shahla; BASSERI, Hamid Reza

    2014-01-01

    The intensity of the conflict such as war is one of the determinants of the flow of migrants and refuges with consequence of introducing infectious disease to other countries. This paper investigates the relationship between malaria incidence and forced immigration due to war from neighboring countries in Dezful district, southwestern Iran. All available data and accessible archived documentary records on malaria cases in the period 1988–2011 in Dezful Health Centers were reviewed. Retrospective analysis of routine surveillance data from the Health authority of Dezful district was conducted to assess the trend of malaria incidence and prevalence in the last two decades. Malaria transmission dynamics was described using surveillance indicators viz, Annual Parasite Incidence (API), Slide Positivity Rate (SPR), Annual Blood Examination Rate (ABER) and based on personal information of patients. Two peaks of malaria incidence occurred during past two decades. The first one arisen by Iran-Iraq war due to residential instability in Dezful while the API reached to 8 per 1000. The second peak happened after to civil war of Afghanistan began which caused large immigrates moved into the study area. During the second peak, API reached 1.7 per 1000 at maximum and the majority of patients were immigrants. This study describes the linkage between incidence and prevalence of malaria and immigration due to civil conflict. Therefore, malaria screening of immigrants and early warning programme are effective to prevent outbreak of disease in a potential risk area such Dezful. PMID:26171354

  2. Mind the Gap: House Structure and the Risk of Malaria in Uganda

    PubMed Central

    Wanzirah, Humphrey; Tusting, Lucy S.; Arinaitwe, Emmanuel; Katureebe, Agaba; Maxwell, Kilama; Rek, John; Bottomley, Christian; Staedke, Sarah G.; Kamya, Moses; Dorsey, Grant; Lindsay, Steve W.

    2015-01-01

    Background Good house construction may reduce the risk of malaria by limiting the entry of mosquito vectors. We assessed how house design may affect mosquito house entry and malaria risk in Uganda. Methods 100 households were enrolled in each of three sub-counties: Walukuba, Jinja district; Kihihi, Kanungu district; and Nagongera, Tororo district. CDC light trap collections of mosquitoes were done monthly in all homes. All children aged six months to ten years (n = 878) were followed prospectively for a total of 24 months to measure parasite prevalence every three months and malaria incidence. Homes were classified as modern (cement, wood or metal walls; and tiled or metal roof; and closed eaves) or traditional (all other homes). Results A total of 113,618 female Anopheles were collected over 6,765 nights. 6,816 routine blood smears were taken of which 1,061 (15.6%) were malaria parasite positive. 2,582 episodes of uncomplicated malaria were diagnosed after 1,569 person years of follow-up, giving an overall incidence of 1.6 episodes per person year at risk. The human biting rate was lower in modern homes than in traditional homes (adjusted incidence rate ratio (IRR) 0.48, 95% confidence interval (CI) 0.37–0.64, p<0.001). The odds of malaria infection were lower in modern homes across all the sub-counties (adjusted odds ratio 0.44, 95%CI 0.30–0.65, p<0.001), while malaria incidence was lower in modern homes in Kihihi (adjusted IRR 0.61, 95%CI 0.40–0.91, p = 0.02) but not in Walukuba or Nagongera. Conclusions House design is likely to explain some of the heterogeneity of malaria transmission in Uganda and represents a promising target for future interventions, even in highly endemic areas. PMID:25635688

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

    PubMed

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

    2016-07-30

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

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

    PubMed

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

    2017-04-12

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

  5. An integrated risk and vulnerability assessment framework for climate change and malaria transmission in East Africa.

    PubMed

    Onyango, Esther Achieng; Sahin, Oz; Awiti, Alex; Chu, Cordia; Mackey, Brendan

    2016-11-11

    Malaria is one of the key research concerns in climate change-health relationships. Numerous risk assessments and modelling studies provide evidence that the transmission range of malaria will expand with rising temperatures, adversely impacting on vulnerable communities in the East African highlands. While there exist multiple lines of evidence for the influence of climate change on malaria transmission, there is insufficient understanding of the complex and interdependent factors that determine the risk and vulnerability of human populations at the community level. Moreover, existing studies have had limited focus on the nature of the impacts on vulnerable communities or how well they are prepared to cope. In order to address these gaps, a systems approach was used to present an integrated risk and vulnerability assessment framework for studies of community level risk and vulnerability to malaria due to climate change. Drawing upon published literature on existing frameworks, a systems approach was applied to characterize the factors influencing the interactions between climate change and malaria transmission. This involved structural analysis to determine influential, relay, dependent and autonomous variables in order to construct a detailed causal loop conceptual model that illustrates the relationships among key variables. An integrated assessment framework that considers indicators of both biophysical and social vulnerability was proposed based on the conceptual model. A major conclusion was that this integrated assessment framework can be implemented using Bayesian Belief Networks, and applied at a community level using both quantitative and qualitative methods with stakeholder engagement. The approach enables a robust assessment of community level risk and vulnerability to malaria, along with contextually relevant and targeted adaptation strategies for dealing with malaria transmission that incorporate both scientific and community perspectives.

  6. Imported malaria and high risk groups: observational study using UK surveillance data 1987-2006

    PubMed Central

    2008-01-01

    Objective To examine temporal, geographic, and sociodemographic trends in case reporting and case fatality of malaria in the United Kingdom. Setting National malaria reference laboratory surveillance data in the UK. Design Observational study using prospectively gathered surveillance data and data on destinations from the international passenger survey. Participants 39 300 cases of proved malaria in the UK between 1987 and 2006. Main outcome measures Plasmodium species; sociodemographic details (including age, sex, and country of birth and residence); mortality; destination, duration, and purpose of international travel; and use of chemoprophylaxis. Results Reported cases of imported malaria increased significantly over the 20 years of the study; an increasing proportion was attributable to Plasmodium falciparum (P falciparum/P vivax reporting ratio 1.3:1 in 1987-91 and 5.4:1 in 2002-6). P vivax reports declined from 3954 in 1987-91 to 1244 in 2002-6. Case fatality of reported P falciparum malaria did not change over this period (7.4 deaths per 1000 reported cases). Travellers visiting friends and relatives, usually in a country in Africa or Asia from which members of their family migrated, accounted for 13 215/20 488 (64.5%) of all malaria reported, and reports were geographically concentrated in areas where migrants from Africa and South Asia to the UK have settled. People travelling for this purpose were at significantly higher risk of malaria than other travellers and were less likely to report the use of any chemoprophylaxis (odds ratio of reported chemoprophylaxis use 0.23, 95% confidence interval 0.21 to 0.25). Conclusions Despite the availability of highly effective preventive measures, the preventable burden from falciparum malaria has steadily increased in the UK while vivax malaria has decreased. Provision of targeted and appropriately delivered preventive messages and services for travellers from migrant families visiting friends and relatives

  7. Patterns and determinants of malaria risk in urban and peri-urban areas of Blantyre, Malawi.

    PubMed

    Mathanga, Don P; Tembo, Atupele Kapito; Mzilahowa, Themba; Bauleni, Andy; Mtimaukenena, Kondwani; Taylor, Terrie E; Valim, Clarissa; Walker, Edward D; Wilson, Mark L

    2016-12-08

    Although malaria disease in urban and peri-urban areas of sub-Saharan Africa is a growing concern, the epidemiologic patterns and drivers of transmission in these settings remain poorly understood. Factors associated with variation in malaria risk in urban and peri-urban areas were evaluated in this study. A health facility-based, age and location-matched, case-control study of children 6-59 months of age was conducted in four urban and two peri-urban health facilities (HF) of Blantyre city, Malawi. Children with fever who sought care from the same HF were tested for malaria parasites by microscopy and PCR. Those testing positive or negative on both were defined as malaria cases or controls, respectively. A total of 187 cases and 286 controls were studied. In univariate analyses, higher level of education, possession of TV, and electricity in the house were negatively associated with malaria illness; these associations were similar in urban and peri-urban zones. Having travelled in the month before testing was strongly associated with clinical malaria, but only for participants living in the urban zones (OR = 5.1; 95% CI = 1.62, 15.8). Use of long-lasting insecticide nets (LLINs) the previous night was not associated with protection from malaria disease in any setting. In multivariate analyses, electricity in the house, travel within the previous month, and a higher level of education were all associated with decreased odds of malaria disease. Only a limited number of Anopheles mosquitoes were found by aspiration inside the households in the peri-urban areas, and none was collected from the urban households. Travel was the main factor influencing the incidence of malaria illness among residents of urban Blantyre compared with peri-urban areas. Identification and understanding of key mobile demographic groups, their behaviours, and the pattern of parasite dispersal is critical to the design of more targeted interventions for the urban setting.

  8. Mapping malaria transmission risk in northern morocco using entomological and environmental data.

    PubMed

    Adlaoui, E; Faraj, C; El Bouhmi, M; El Aboudi, A; Ouahabi, S; Tran, A; Fontenille, D; El Aouad, R

    2011-01-01

    Malaria resurgence risk in Morocco depends, among other factors, on environmental changes as well as the introduction of parasite carriers. The aim of this paper is to analyze the receptivity of the Loukkos area, large wetlands in Northern Morocco, to quantify and to map malaria transmission risk in this region using biological and environmental data. This risk was assessed on entomological risk basis and was mapped using environmental markers derived from satellite imagery. Maps showing spatial and temporal variations of entomological risk for Plasmodium vivax and P. falciparum were produced. Results showed this risk to be highly seasonal and much higher in rice fields than in swamps. This risk is lower for Afrotropical P. falciparum strains because of the low infectivity of Anopheles labranchiae, principal malaria vector in Morocco. However, it is very high for P. vivax mainly during summer corresponding to the rice cultivation period. Although the entomological risk is high in Loukkos region, malaria resurgence risk remains very low, because of the low vulnerability of the area.

  9. Malaria successes and challenges in Asia.

    PubMed

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

    2013-12-01

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

  10. AN OVERVIEW OF THE USE OF QSARS FOR RANKING AND PRIORITIZING LARGE CHEMICAL INVENTORIES FOR ENVIRONMENTAL RISK ASSESSMENT

    EPA Science Inventory

    Ecological risk assessments for chemical stressors are used to establish linkages between likely exposure concentrations and adverse effects to ecological receptors. At times, it is useful to conduct screening risk assessments to assist in prioritizing or ranking chemicals on the...

  11. AN OVERVIEW OF THE USE OF QSARS FOR RANKING AND PRIORITIZING LARGE CHEMICAL INVENTORIES FOR ENVIRONMENTAL RISK ASSESSMENT

    EPA Science Inventory

    Ecological risk assessments for chemical stressors are used to establish linkages between likely exposure concentrations and adverse effects to ecological receptors. At times, it is useful to conduct screening risk assessments to assist in prioritizing or ranking chemicals on the...

  12. Discrepancies between multicriteria decision analysis-based ranking and intuitive ranking for pharmaceutical benefit-risk profiles in a hypothetical setting.

    PubMed

    Hoshikawa, K; Ono, S

    2017-02-01

    Multicriteria decision analysis (MCDA) has been generally considered a promising decision-making methodology for the assessment of drug benefit-risk profiles. There have been many discussions in both public and private sectors on its feasibility and applicability, but it has not been employed in official decision-makings. For the purpose of examining to what extent MCDA would reflect the first-hand, intuitive preference of evaluators in practical pharmaceutical assessments, we conducted a questionnaire survey involving the participation of employees of pharmaceutical companies. Showing profiles of the efficacy and safety of four hypothetical drugs, each respondent was asked to rank them following the standard MCDA process and then to rank them intuitively (i.e. without applying any analytical framework). These two approaches resulted in substantially different ranking patterns from the same individuals, and the concordance rate was surprisingly low (17%). Although many respondents intuitively showed a preference for mild, balanced risk-benefit profiles over profiles with a conspicuous advantage in either risk or benefit, the ranking orders based on MCDA scores did not reflect the intuitive preference. Observed discrepancies between the rankings seemed to be primarily attributed to the structural characteristics of MCDA, which assumes that evaluation on each benefit and risk component should have monotonic impact on final scores. It would be difficult for MCDA to reflect commonly observed non-monotonic preferences for risk and benefit profiles. Possible drawbacks of MCDA should be further investigated prior to the real-world application of its benefit-risk assessment. © 2016 John Wiley & Sons Ltd.

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

    PubMed

    Kumar, Rajesh; Dash, Chinmaya; Rani, Khushbu

    2017-09-01

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

  14. Urban malaria risk in sub-Saharan Africa: where is the evidence?

    PubMed

    Byrne, Neville

    2007-03-01

    It is essential that the precautions that are advisable for travel in sub-Saharan Africa, including antimalarial prophylaxis, are supported by evidence. Sub-Saharan Africa accounts for 90% of global malaria cases and the more serious falciparum form predominates. The risk of malaria transmission is qualitatively much greater in rural than urban areas. However, there is little quantitative data on the risk in urban areas on which to base a risk assessment. Rapid urban population growth and trends of tourism to urban-only (rather than rural) areas both support the need to focus attention on the level of risk in malaria endemic African cities. There is evidence in urban settings that the reduced intensity of malaria transmission is due to a decline in the level of parasitism in the local population and reduced anophelism. The most useful evidence for an urban risk assessment is the entomological inoculation rate (EIR) which is generally below 30 infective bites per person per year. Transmission is acknowledged to be much lower in central urban areas compared with peri-urban areas or rural areas. Transmission is local and focal because the anopheles mosquito has a limited flight range of several kilometres. The risk assessment should examine nocturnal activities outside an air-conditioned environment (because the anopheline mosquito only bites between dusk and dawn) and the level of adherence to accompanying protective measures. Several studies have noted the protection air-conditioning provides against malaria. Evidence of low occupational risk for airline crew, unprotected by prophylaxis, from brief layovers of several nights in quality hotels in 8 endemic cities is explored. A literature search examines the evidence of environmental surveys and entomological inoculation rates. The limitations of the available data are discussed, including the highly focal nature of malaria transmission.

  15. Population Density, Climate Variables and Poverty Synergistically Structure Spatial Risk in Urban Malaria in India

    PubMed Central

    Santos-Vega, Mauricio; Bouma, Menno J; Kohli, Vijay; Pascual, Mercedes

    2016-01-01

    Background The world is rapidly becoming urban with the global population living in cities projected to double by 2050. This increase in urbanization poses new challenges for the spread and control of communicable diseases such as malaria. In particular, urban environments create highly heterogeneous socio-economic and environmental conditions that can affect the transmission of vector-borne diseases dependent on human water storage and waste water management. Interestingly India, as opposed to Africa, harbors a mosquito vector, Anopheles stephensi, which thrives in the man-made environments of cities and acts as the vector for both Plasmodium vivax and Plasmodium falciparum, making the malaria problem a truly urban phenomenon. Here we address the role and determinants of within-city spatial heterogeneity in the incidence patterns of vivax malaria, and then draw comparisons with results for falciparum malaria. Methodology/principal findings Statistical analyses and a phenomenological transmission model are applied to an extensive spatio-temporal dataset on cases of Plasmodium vivax in the city of Ahmedabad (Gujarat, India) that spans 12 years monthly at the level of wards. A spatial pattern in malaria incidence is described that is largely stationary in time for this parasite. Malaria risk is then shown to be associated with socioeconomic indicators and environmental parameters, temperature and humidity. In a more dynamical perspective, an Inhomogeneous Markov Chain Model is used to predict vivax malaria risk. Models that account for climate factors, socioeconomic level and population size show the highest predictive skill. A comparison to the transmission dynamics of falciparum malaria reinforces the conclusion that the spatio-temporal patterns of risk are strongly driven by extrinsic factors. Conclusion/significance Climate forcing and socio-economic heterogeneity act synergistically at local scales on the population dynamics of urban malaria in this city. The

  16. Population Density, Climate Variables and Poverty Synergistically Structure Spatial Risk in Urban Malaria in India.

    PubMed

    Santos-Vega, Mauricio; Bouma, Menno J; Kohli, Vijay; Pascual, Mercedes

    2016-12-01

    The world is rapidly becoming urban with the global population living in cities projected to double by 2050. This increase in urbanization poses new challenges for the spread and control of communicable diseases such as malaria. In particular, urban environments create highly heterogeneous socio-economic and environmental conditions that can affect the transmission of vector-borne diseases dependent on human water storage and waste water management. Interestingly India, as opposed to Africa, harbors a mosquito vector, Anopheles stephensi, which thrives in the man-made environments of cities and acts as the vector for both Plasmodium vivax and Plasmodium falciparum, making the malaria problem a truly urban phenomenon. Here we address the role and determinants of within-city spatial heterogeneity in the incidence patterns of vivax malaria, and then draw comparisons with results for falciparum malaria. Statistical analyses and a phenomenological transmission model are applied to an extensive spatio-temporal dataset on cases of Plasmodium vivax in the city of Ahmedabad (Gujarat, India) that spans 12 years monthly at the level of wards. A spatial pattern in malaria incidence is described that is largely stationary in time for this parasite. Malaria risk is then shown to be associated with socioeconomic indicators and environmental parameters, temperature and humidity. In a more dynamical perspective, an Inhomogeneous Markov Chain Model is used to predict vivax malaria risk. Models that account for climate factors, socioeconomic level and population size show the highest predictive skill. A comparison to the transmission dynamics of falciparum malaria reinforces the conclusion that the spatio-temporal patterns of risk are strongly driven by extrinsic factors. Climate forcing and socio-economic heterogeneity act synergistically at local scales on the population dynamics of urban malaria in this city. The stationarity of malaria risk patterns provides a basis for more

  17. Urban malaria and associated risk factors in Jimma town, south-west Ethiopia

    PubMed Central

    2011-01-01

    Background Malaria kills millions around the world. Until recently it was believed to be a disease of rural areas, since the Anopheles mosquito, which transmits Plasmodium species breeds in rural areas. Urban malaria is emerging as a potential, but "avertable" crisis, in Africa. In view of the rapidly growing number of small and medium-sized towns in Ethiopia there is a pressing need to improve the understanding of the epidemiology of malaria. Therefore, the aim of this study was to determine malaria prevalence and associated risk factors in Jimma town. Methods A cross-sectional study was carried out in Jimma town from April 1 to May 28, 2010. 804 study participants were included from 291 households for microscopic examination of malaria parasites. Socio-demography data and risk factors were collected using structured questionnaires. Logistic regression analysis was done using SPSS 15.0 statistical software. Results From a total of 804 study participants in current survey only 42 (5.2%) were positive for malaria parasites. Plasmodium vivax, Plasmodium falciparum and mixed infection accounted 71.4%, 26.2% and 2.4%, respectively. Higher malaria prevalence rate was observed among under-five children (11%). Those who do not use insecticide-treated bed nets (ITN) were more likely to be infected with malaria (OR = 13.6; 95% CI 4.9-37.2, p < 0.001) compared with those who use the ITN. Living in areas where stagnant water existed (OR = 2.1; 95% CI 1.00-4.2, p = 0.047) and its distance of existence <1 km from the house(OR = 2.1; 95% CI 2.0-15.8, p = 0.001) were more likely to be infected with malaria parasite compared with those who live away from stagnant at a distance greater than 1 km. Conclusion Malaria is a major health problem with P. vivax becoming a predominant species in the town. The prevalence was strongly associated with proximity of residence to potential mosquito breeding sites. Malaria is affecting significant proportions of the urban settlers and human

  18. Climate Change Is Increasing the Risk of the Reemergence of Malaria in Romania

    PubMed Central

    Bodale, Ilie; Florescu, Simin-Aysel; Roman, Constantin; Acatrinei, Dumitru

    2016-01-01

    The climatic modifications lead to global warming; favouring the risk of the appearance and development of diseases are considered until now tropical diseases. Another important factor is the workers' immigration, the economic crisis favouring the passive transmission of new species of culicidae from different areas. Malaria is the disease with the widest distribution in the globe. Millions of people are infected every year in Africa, India, South-East Asia, Middle East, and Central and South America, with more than 41% of the global population under the risk of infestation with malaria. The increase of the number of local cases reported in 2007–2011 indicates that the conditions can favour the high local transmission in the affected areas. In the situation presented, the establishment of the level of risk concerning the reemergence of malaria in Romania becomes a priority. PMID:27847824

  19. Development of nutritionally at-risk young children is predicted by malaria, anemia, and stunting in Pemba, Zanzibar

    USDA-ARS?s Scientific Manuscript database

    Nutritionally at-risk children suffer delays in physical growth and motor and language development. Infectious diseases such as malaria pose an additional risk. We examined the cross-sectional relationships among malaria infection, hemoglobin (Hb) concentration, length-for-age Z-scores (LAZ), motor ...

  20. The influence of mosquito resting behaviour and associated microclimate for malaria risk

    PubMed Central

    2011-01-01

    Background The majority of the mosquito and parasite life-history traits that combine to determine malaria transmission intensity are temperature sensitive. In most cases, the process-based models used to estimate malaria risk and inform control and prevention strategies utilize measures of mean outdoor temperature. Evidence suggests, however, that certain malaria vectors can spend large parts of their adult life resting indoors. Presentation of hypothesis If significant proportions of mosquitoes are resting indoors and indoor conditions differ markedly from ambient conditions, simple use of outdoor temperatures will not provide reliable estimates of malaria transmission intensity. To date, few studies have quantified the differential effects of indoor vs outdoor temperatures explicitly, reflecting a lack of proper understanding of mosquito resting behaviour and associated microclimate. Testing the hypothesis Published records from 8 village sites in East Africa revealed temperatures to be warmer indoors than outdoors and to generally show less daily variation. Exploring the effects of these temperatures on malaria parasite development rate suggested indoor-resting mosquitoes could transmit malaria between 0.3 and 22.5 days earlier than outdoor-resting mosquitoes. These differences translate to increases in transmission risk ranging from 5 to approaching 3,000%, relative to predictions based on outdoor temperatures. The pattern appears robust for low- and highland areas, with differences increasing with altitude. Implications of the hypothesis Differences in indoor vs outdoor environments lead to large differences in the limits and the intensity of malaria transmission. This finding highlights a need to better understand mosquito resting behaviour and the associated microclimate, and to broaden assessments of transmission ecology and risk to consider the potentially important role of endophily. PMID:21736735

  1. Desirability of Outcome Ranking (DOOR) and Response Adjusted for Duration of Antibiotic Risk (RADAR).

    PubMed

    Evans, Scott R; Rubin, Daniel; Follmann, Dean; Pennello, Gene; Huskins, W Charles; Powers, John H; Schoenfeld, David; Chuang-Stein, Christy; Cosgrove, Sara E; Fowler, Vance G; Lautenbach, Ebbing; Chambers, Henry F

    2015-09-01

    Clinical trials that compare strategies to optimize antibiotic use are of critical importance but are limited by competing risks that distort outcome interpretation, complexities of noninferiority trials, large sample sizes, and inadequate evaluation of benefits and harms at the patient level. The Antibacterial Resistance Leadership Group strives to overcome these challenges through innovative trial design. Response adjusted for duration of antibiotic risk (RADAR) is a novel methodology utilizing a superiority design and a 2-step process: (1) categorizing patients into an overall clinical outcome (based on benefits and harms), and (2) ranking patients with respect to a desirability of outcome ranking (DOOR). DOORs are constructed by assigning higher ranks to patients with (1) better overall clinical outcomes and (2) shorter durations of antibiotic use for similar overall clinical outcomes. DOOR distributions are compared between antibiotic use strategies. The probability that a randomly selected patient will have a better DOOR if assigned to the new strategy is estimated. DOOR/RADAR represents a new paradigm in assessing the risks and benefits of new strategies to optimize antibiotic use. © The Author 2015. 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.

  2. Desirability of Outcome Ranking (DOOR) and Response Adjusted for Duration of Antibiotic Risk (RADAR)

    PubMed Central

    Evans, Scott R.; Rubin, Daniel; Follmann, Dean; Pennello, Gene; Huskins, W. Charles; Powers, John H.; Schoenfeld, David; Chuang-Stein, Christy; Cosgrove, Sara E.; Fowler, Vance G.; Lautenbach, Ebbing; Chambers, Henry F.

    2015-01-01

    Clinical trials that compare strategies to optimize antibiotic use are of critical importance but are limited by competing risks that distort outcome interpretation, complexities of noninferiority trials, large sample sizes, and inadequate evaluation of benefits and harms at the patient level. The Antibacterial Resistance Leadership Group strives to overcome these challenges through innovative trial design. Response adjusted for duration of antibiotic risk (RADAR) is a novel methodology utilizing a superiority design and a 2-step process: (1) categorizing patients into an overall clinical outcome (based on benefits and harms), and (2) ranking patients with respect to a desirability of outcome ranking (DOOR). DOORs are constructed by assigning higher ranks to patients with (1) better overall clinical outcomes and (2) shorter durations of antibiotic use for similar overall clinical outcomes. DOOR distributions are compared between antibiotic use strategies. The probability that a randomly selected patient will have a better DOOR if assigned to the new strategy is estimated. DOOR/RADAR represents a new paradigm in assessing the risks and benefits of new strategies to optimize antibiotic use. PMID:26113652

  3. In vitro growth-inhibitory activity and malaria risk in a cohort study in mali.

    PubMed

    Crompton, Peter D; Miura, Kazutoyo; Traore, Boubacar; Kayentao, Kassoum; Ongoiba, Aissata; Weiss, Greta; Doumbo, Safiatou; Doumtabe, Didier; Kone, Younoussou; Huang, Chiung-Yu; Doumbo, Ogobara K; Miller, Louis H; Long, Carole A; Pierce, Susan K

    2010-02-01

    Immunity to the asexual blood stage of Plasmodium falciparum is complex and likely involves several effector mechanisms. Antibodies are thought to play a critical role in malaria immunity, and a corresponding in vitro correlate of antibody-mediated immunity has long been sought to facilitate malaria vaccine development. The growth inhibition assay (GIA) measures the capacity of antibodies to limit red blood cell (RBC) invasion and/or growth of P. falciparum in vitro. In humans, naturally acquired and vaccine-induced P. falciparum-specific antibodies have growth-inhibitory activity, but it is unclear if growth-inhibitory activity correlates with protection from clinical disease. In a longitudinal study in Mali, purified IgGs, obtained from plasmas collected before the malaria season from 220 individuals aged 2 to 10 and 18 to 25 years, were assayed for growth-inhibitory activity. Malaria episodes were recorded by passive surveillance over the subsequent 6-month malaria season. Logistic regression showed that greater age (odds ratio [OR], 0.78; 95% confidence interval [95% CI], 0.63 to 0.95; P = 0.02) and growth-inhibitory activity (OR, 0.50; 95% CI, 0.30 to 0.85; P = 0.01) were significantly associated with decreased malaria risk in children. A growth-inhibitory activity level of 40% was determined to be the optimal cutoff for discriminating malaria-immune and susceptible individuals in this cohort, with a sensitivity of 97.0%, but a low specificity of 24.3%, which limited the assay's ability to accurately predict protective immunity and to serve as an in vitro correlate of antibody-mediated immunity. These data suggest that antibodies which block merozoite invasion of RBC and/or inhibit the intra-RBC growth of the parasite contribute to but are not sufficient for the acquisition of malaria immunity.

  4. The Indian Ocean Dipole and malaria risk in the highlands of western Kenya.

    PubMed

    Hashizume, Masahiro; Terao, Toru; Minakawa, Noboru

    2009-02-10

    Epidemics of malaria in the East African highlands in the last 2 decades have often been associated with climate variability, particularly the El Niño-Southern Oscillation (ENSO). However, there are other factors associated with malaria risk and there is increased interest in the influences of the Indian Ocean Dipole (IOD), a climate mode of coupled ocean-atmosphere variability, on East African rainfall. This study explores the relationship between IOD and the number of malaria patients in 7 hospitals from 2 districts in the western Kenyan highlands, controlling for the effects of ENSO. We examined temporal patterns (1982-2001) in the number of malaria cases in relation to the dipole mode index (DMI), defined as the difference in sea surface temperature anomaly between the western (10 degrees S-10 degrees N, 50 degrees-70 degrees E) and eastern (10 degrees S-0 degrees, 90 degrees-110 degrees E) tropical Indian Ocean. We used Poisson regression models, adjusted for ENSO index Niño 3 region (NINO3), seasonal and interannual variations. The number of malaria patients per month increased by 3.4%-17.9% for each 0.1 increase above a DMI threshold (3-4 months lag). Malaria cases increased by 1.4%-10.7% per month, for each 10 mm increase in monthly rainfall (2-3 months lag). In 6 of 7 places, there was no evidence of an association between NINO3 and the number of malaria cases after adjusting for the effect of DMI. This study suggests that the number of malaria cases in the western Kenyan highlands increases with high DMI in the months preceding hospital visits.

  5. The low and declining risk of malaria in travellers to Latin America: is there still an indication for chemoprophylaxis?

    PubMed Central

    Behrens, Ron H; Carroll, Bernadette; Beran, Jiri; Bouchaud, Olivier; Hellgren, Urban; Hatz, Christoph; Jelinek, Tomas; Legros, Fabrice; Mühlberger, Nikolai; Myrvang, Bjørn; Siikamäki, Heli; Visser, Leo

    2007-01-01

    A comparison was made between local malaria transmission and malaria imported by travellers to identify the utility of national and regional annual parasite index (API) in predicting malaria risk and its value in generating recommendations on malaria prophylaxis for travellers. Regional malaria transmission data was correlated with malaria acquired in Latin America and imported into the USA and nine European countries. Between 2000 and 2004, most countries reported declining malaria transmission. Highest API's in 2003/4 were in Surinam (287.4) Guyana (209.2) and French Guiana (147.4). The major source of travel associated malaria was Honduras, French Guiana, Guatemala, Mexico and Ecuador. During 2004 there were 6.3 million visits from the ten study countries and in 2005, 209 cases of malaria of which 22 (11%) were Plasmodium falciparum. The risk of adverse events are high and the benefit of avoided benign vivax malaria is very low under current policy, which may be causing more harm than benefit. PMID:17716367

  6. The effect of social rank feedback on risk taking and associated reward processes in adolescent girls

    PubMed Central

    Bunge, Silvia A.; Bell, Orly N.; Kriegsfeld, Lance J.; Kayser, Andrew S.; Dahl, Ronald E.

    2017-01-01

    Abstract The onset of adolescence is associated with an increased tendency to engage in risky behaviors and a developmental shift toward peers that contributes to increased prioritization for learning about and achieving social status. There is relatively little understanding about the specific links between these adolescent-typical phenomena, particularly regarding their neural underpinnings. Based on existing models that suggest the role of puberty in promoting adolescent status-seeking and risk-taking tendencies, we investigated the relation of pubertal hormones with behavioral and neural responses to status-relevant social information in the context of risk taking. We used a probabilistic decision task in which 11- to 13-year-old girls chose to take a risk, or not, while receiving either social rank or monetary performance feedback. While feedback type did not differentially influence risk-taking behavior, whole-brain imaging results showed that activation in the anterior insula was increased for risk taking in the social rank feedback condition compared to the monetary feedback condition. This heightened activation was more pronounced in girls with higher estradiol levels. These findings suggest that brain processes involved in adolescent risky decisions may be influenced by the desire for social-status enhancement and provide preliminary evidence for the role of pubertal hormones in enhancing this adolescent-typical social sensitivity. PMID:27614768

  7. Malaria and schistosomiasis risks associated with surface and sprinkler irrigation systems in Zimbabwe.

    PubMed

    Chimbari, M J; Chirebvu, E; Ndlela, B

    2004-01-01

    A comparative assessment of the malaria and schistosomiasis risks associated with surface and sprinkler irrigation systems in Zimbabwe was carried out. The risk assessment of the two diseases was done in accordance with the three standard components of health impact assessment, namely (i) community vulnerability, (ii) environmental receptivity, and (iii) capability of health services to respond to malaria and schistosomiasis. Records of the two diseases were obtained from four health centres serving two surface irrigation schemes and two sprinkler irrigation schemes. For comparison records were also obtained from health centres serving nearby dryland areas. Incidence of schistosomiasis as estimated from recorded new cases of the disease was much higher in surface irrigation schemes than in sprinkler irrigation schemes. For malaria it was the other way around. These findings were confirmed by rapid risk assessments. Malaria risk factors were more prominent in sprinkler irrigation schemes, whereas more schistosomiasis risk factors were identified in surface irrigation schemes. These observations were attributed to poorly maintained infrastructure and inadequate landscape-levelling, which created mosquito breeding sites within the fields in the case of sprinkler schemes, and to poor drainage structures, which created snail-breeding sites in the case of surface-irrigation schemes. Importantly, poor maintenance of sprinkler scheme infrastructure accounted for more disease promoting features than the engineering designs per se. This study demonstrated the value of complementing routinely collected health data with rapid assessment procedures for appraisal of commonly reported diseases.

  8. The importance of temperature fluctuations in understanding mosquito population dynamics and malaria risk

    PubMed Central

    Nelson, William A.; Paaijmans, Krijn P.; Thomas, Matthew B.; Bjørnstad, Ottar N.

    2017-01-01

    Temperature is a key environmental driver of Anopheles mosquito population dynamics; understanding its central role is important for these malaria vectors. Mosquito population responses to temperature fluctuations, though important across the life history, are poorly understood at a population level. We used stage-structured, temperature-dependent delay-differential equations to conduct a detailed exploration of the impacts of diurnal and annual temperature fluctuations on mosquito population dynamics. The model allows exploration of temperature-driven temporal changes in adult age structure, giving insights into the population’s capacity to vector malaria parasites. Because of temperature-dependent shifts in age structure, the abundance of potentially infectious mosquitoes varies temporally, and does not necessarily mirror the dynamics of the total adult population. In addition to conducting the first comprehensive theoretical exploration of fluctuating temperatures on mosquito population dynamics, we analysed observed temperatures at four locations in Africa covering a range of environmental conditions. We found both temperature and precipitation are needed to explain the observed malaria season in these locations, enhancing our understanding of the drivers of malaria seasonality and how temporal disease risk may shift in response to temperature changes. This approach, tracking both mosquito abundance and age structure, may be a powerful tool for understanding current and future malaria risk. PMID:28405386

  9. Ranking Businesses and Municipal Locations by Spatiotemporal Cardiac Arrest Risk to Guide Public Defibrillator Placement.

    PubMed

    Sun, Christopher L F; Brooks, Steven C; Morrison, Laurie J; Chan, Timothy C Y

    2017-03-21

    Efforts to guide automated external defibrillator placement for out-of-hospital cardiac arrest (OHCA) treatment have focused on identifying broadly defined location categories without considering hours of operation. Broad location categories may be composed of many businesses with varying accessibility. Identifying specific locations for automated external defibrillator deployment incorporating operating hours and time of OHCA occurrence may improve automated external defibrillator accessibility. We aim to identify specific businesses and municipal locations that maximize OHCA coverage on the basis of spatiotemporal assessment of OHCA risk in the immediate vicinity of franchise locations. This study was a retrospective population-based cohort study using data from the Toronto Regional RescuNET Epistry cardiac arrest database. We identified all nontraumatic public OHCAs occurring in Toronto, ON, Canada, from January 2007 through December 2015. We identified 41 unique businesses and municipal location types with ≥20 locations in Toronto from the YellowPages, Canadian Franchise Association, and the City of Toronto Open Data Portal. We obtained their geographic coordinates and hours of operation from Web sites, by phone, or in person. We determined the number of OHCAs that occurred within 100 m of each location when it was open (spatiotemporal coverage) for Toronto overall and downtown. The businesses and municipal locations were then ranked by spatiotemporal OHCA coverage. To evaluate temporal stability of the rankings, we calculated intraclass correlation of the annual coverage values. There were 2654 nontraumatic public OHCAs. Tim Hortons ranked first in Toronto, covering 286 OHCAs. Starbucks ranked first in downtown, covering 110 OHCAs. Coffee shops and bank machines from the 5 largest Canadian banks occupied 8 of the top 10 spots in both Toronto and downtown. The rankings exhibited high temporal stability with intraclass correlation values of 0.88 (95

  10. Risk Factors for Helminth, Malaria, and HIV Infection in Pregnancy in Entebbe, Uganda

    PubMed Central

    Woodburn, Patrick William; Muhangi, Lawrence; Hillier, Stephen; Ndibazza, Juliet; Namujju, Proscovia Bazanya; Kizza, Moses; Ameke, Christine; Omoding, Nicolas Emojong; Booth, Mark; Elliott, Alison Mary

    2009-01-01

    Background Infections during pregnancy may have serious consequences for both mother and baby. Assessment of risk factors for infections informs planning of interventions and analysis of the impact of infections on health outcomes. Objectives To describe risk factors for helminths, malaria and HIV in pregnant Ugandan women before intervention in a trial of de-worming in pregnancy. Methods The trial recruited 2,507 pregnant women between April 2003 and November 2005. Participants were interviewed and blood and stool samples obtained; location of residence at enrolment was mapped. Demographic, socioeconomic, behavioral and other risk factors were modelled using logistic regression. Results There was a high prevalence of helminth, malaria and HIV infection, as previously reported. All helminths and malaria parasitemia were more common in younger women, and education was protective against every infection. Place of birth and/or tribe affected all helminths in a pattern consistent with the geographical distribution of helminth infections in Uganda. Four different geohelminths (hookworm, Trichuris, Ascaris and Trichostrongylus) showed a downwards trend in prevalence during the enrolment period. There was a negative association between hookworm and HIV, and between hookworm and low CD4 count among HIV-positive women. Locally, high prevalence of schistosomiasis and HIV occurred in lakeshore communities. Conclusions Interventions for helminths, malaria and HIV need to target young women both in and out of school. Antenatal interventions for malaria and HIV infection must continue to be promoted. Women originating from a high risk area for a helminth infection remain at high risk after migration to a lower-risk area, and vice versa, but overall, geohelminths seem to be becoming less common in this population. High risk populations, such as fishing communities, require directed effort against schistosomiasis and HIV infection. PMID:19564904

  11. Malaria risk factors in Amerindian children in French Guiana.

    PubMed

    Hustache, Sarah; Nacher, Mathieu; Djossou, Félix; Carme, Bernard

    2007-04-01

    Malaria is a major public health problem in French Guiana. This study was conducted in children <1-5 years of age in Camopi, an Amerindian village in eastern French Guiana. Medical, environmental, and behavioral predictive factors of malaria were studied using the Kaplan-Meier method and Cox modeling. Variables included were clearing vegetation around the home (hazard ratio [HR] = 0.62, 95% confidence interval [CI] = 0.43-0.88 for 50-75% cleared and HR = 0.5, 95% CI = 0.31-0.81 for > 75% cleared) relative to homes surrounded by vegetation; distance of a home from a river (HR = 0.56, 95% CI = 0.37-0.85 for distances between 20 and 40 meters, HR = 0.72, 95% CI = 0.47-1.09 for distances between 40 and 80 meters, HR = 0.52, 95% CI = 0.28-0.94 for distances between 80 and 120 meters, and HR = 0.5, 95% CI = 0.30-0.86 for distances > 120 meters) relative to distances < 20 meters; the number of occupants in the home (HR = 1.54, 95% CI = 0.98-2.44 for 7 occupants, HR = 1.9, 95% CI = 1.29-2.81 for 8-11 occupants, and HR = 2.03, 95% CI = 1.27-3.23 for > 11 occupants); clothing (HR = 0.64, 95% CI = 0.46-0.90 for children wearing western-style clothes relative to those wearing the traditional kalimbe), and ethnicity (Wayampi children had a lower hazard of malaria relative to Emerillon children: HR = 0.55, 95% CI = 0.40-0.80). The environment near the home was strongly associated with malaria. This suggests that simple pragmatic protection measures would be useful in Camopi.

  12. Ranking freshwater fish farms for the risk of pathogen introduction and spread.

    PubMed

    Oidtmann, B C; Crane, C N; Thrush, M A; Hill, B J; Peeler, E J

    2011-12-15

    A semi-quantitative model is presented to rank freshwater rainbow trout farms within a country or region with regards to the risk of becoming infected and spreading a specified pathogen. The model was developed to support a risk-based surveillance scheme for notifiable salmonid pathogens. Routes of pathogen introduction and spread were identified through a process of expert consultation in a series of workshops. The routes were combined into themes (e.g. exposure via water, mechanical transmission). Themes were weighted based on expert opinion. Risk factors for each route were scored and combined into a theme score which was adjusted by the weight. The number of sources and consignments were used to assess introduction via live fish movements onto the farm. Biosecurity measures were scored to assess introduction on fomites. Upstream farms, wild fish and processing plants were included in assessing the likelihood of introduction by water. The scores for each theme were combined to give separate risk scores for introduction and spread. A matrix was used to combine these to give an overall risk score. A case study for viral haemorrhagic septicaemia is presented. Nine farms that represent a range of farming practices of rainbow trout farms in England and Wales are used as worked examples of the model. The model is suited to risk rank freshwater salmonid farms which are declared free of the pathogen(s) under consideration. The score allocated to a farm does not equate to a quantitative probability estimate of the farm to become infected or spread infection. Nevertheless, the method provides a transparent approach to ranking farms with regards to pathogen transmission risks. The output of the model at a regional or national level allows the allocation of surveillance effort to be risk based. It also provides fish farms with information on how they can reduce their risk score by improving biosecurity. The framework of the model can be applied to different production

  13. Global risk factor rankings: the importance of age-based health loss inequities caused by alcohol and other risk factors.

    PubMed

    Shield, Kevin D; Rehm, Jürgen

    2015-06-09

    Achieving health equity is a priority of the World Health Organization; however, there is a scant amount of literature on this topic. As the underlying influences that determine health loss caused by risk factors are age-dependent, the aim of this paper is to examine how the risk factor rankings for health loss differ by age. Rankings were based on data obtained from the 2010 Global Burden of Disease study. Health loss (as measured by Disability Adjusted Life Years lost) by risk factor was estimated using Population-Attributable Fractions, years of life lost due to premature mortality, and years lived with disability, which were calculated for 187 countries, 20 age groups and both sexes. Uncertainties of the risk factor rankings were estimated using 1,000 simulations taken from posterior distributions The top risk factors by age were: household air pollution for neonates 0-6 days of age [95% uncertainty interval (UI): 1 to 1]; suboptimal breast feeding for children 7-27 days of age (95% UI: 1-1); childhood underweight for children 28 days to less than 1 year of age and 1-4 years of age (95% UI: 1-2 and 1-1, respectively); iron deficiency for children and youth 5-14 years of age (95% UI: 1-1); alcohol use for people 15-49 years of age (95% UI: 1-2); and dietary risks for people 50 years of age and older (95% UI: 1-1). Rankings of risk factors varied by sex among the older age groups. Alcohol and smoking were the most important risk factors among men 15 years of age and older, and high body mass and intimate partner violence were some of the most important risk factors among women 15 years of age and older. Our analyses confirm that the relative importance of risk factors is age-dependent. Therefore, preventing harms caused by various modifiable risk factors using interventions that target people of different ages should be a priority, especially since easily implemented and cost-effective public health interventions exist.

  14. The participatory vulnerability scoping diagram - deliberative risk ranking for community water systems

    USGS Publications Warehouse

    Howe, Peter D.; Yarnal, Brent; Coletti, Alex; Wood, Nathan J.

    2013-01-01

    Natural hazards and climate change present growing challenges to community water system (CWS) managers, who are increasingly turning to vulnerability assessments to identify, prioritize, and adapt to risks. Effectively assessing CWS vulnerability requires information and participation from various sources, one of which is stakeholders. In this article, we present a deliberative risk-ranking methodology, the participatory vulnerability scoping diagram (P-VSD), which allows rapid assessment and integration of multiple stakeholder perspectives of vulnerability. This technique is based on methods of deliberative risk evaluation and the vulnerability scoping diagram. The goal of the methodology is to engage CWS managers and stakeholders collectively to provide qualitative contextual risk rankings as a first step in a vulnerability assessment. We conduct an initial assessment using a case study of CWS in two U.S. counties, sites with broadly similar exposures but differences in population, land use, and other social sensitivity factors. Results demonstrate that CWS managers and stakeholders in the two case study communities all share the belief that their CWS are vulnerable to hazards but differ in how this vulnerability manifests itself in terms of the exposure, sensitivity, and adaptive capacity of the system.

  15. Evaluation of a Web-Based Malaria Risk Reduction Game for Study Abroad Students

    PubMed Central

    Hartjes, Laurie B.; Baumann, Linda C.

    2012-01-01

    Objective Compare feedback strategies in three versions of an educational game. Participants Study abroad students (N = 482) participated by playing the game and completing pre-game/post-game surveys January-March 2010. Methods This study employed an experimental design. Primary outcome measures were knowledge gain, player-satisfaction, and risk perception. Results One-third had previously traveled to a malaria-risk region and two-thirds planned to do so. Baseline malaria knowledge was low. Post-game knowledge and risk perception were significantly higher than pre-game, irrespective of past travel status. The group that automatically received explanatory feedback following game decisions scored higher for mean knowledge gain, without differences in player-satisfaction. Conclusions The challenges of designing a feedback strategy to support Web-based learning make these results highly relevant to health educators developing interactive multimedia interventions. The increasing number of students traveling to higher-risk destinations demands attention. Both malaria-naive and malaria-experienced students would benefit from this approach to travel health education. PMID:22686363

  16. Analytical Hierarchy Process modeling for malaria risk zones in Vadodara district, Gujarat

    NASA Astrophysics Data System (ADS)

    Bhatt, B.; Joshi, J. P.

    2014-11-01

    Malaria epidemic is one of the complex spatial problems around the world. According to WHO, an estimated 6, 27, 000 deaths occurred due to malaria in 2012. In many developing nations with diverse ecological regions, it is still a large cause of human mortality. Owing to the incompleteness of epidemiological data and their spatial origin, the quantification of disease incidence burdening basic public health planning is a major constrain especially in developing countries. The present study focuses on the integrated Geospatial and Multi-Criteria Evaluation (AHP) technique to determine malaria risk zones. The study is conducted in Vadodara district, including 12 Taluka among which 4 Taluka are predominantly tribal. The influence of climatic and physical environmental factors viz., rainfall, hydro geomorphology; drainage, elevation, and land cover are used to score their share in the evaluation of malariogenic condition. This was synthesized on the basis of preference over each factor and the total weights of each data and data layer were computed and visualized. The district was divided into three viz., high, moderate and low risk zones .It was observed that a geographical area of 1885.2sq.km comprising 30.3% fall in high risk zone. The risk zones identified on the basis of these parameters and assigned weights shows a close resemblance with ground condition. As the API distribution for 2011overlaid corresponds to the risk zones identified. The study demonstrates the significance and prospect of integrating Geospatial tools and Analytical Hierarchy Process for malaria risk zones and dynamics of malaria transmission.

  17. Knowledge, attitudes, and practices toward malaria risk and prevention among frequent business travelers of a major oil and gas company.

    PubMed

    Berg, Johannes; Breederveld, Daan; Roukens, Anna H; Hennink, Yvonne; Schouten, Marjolijn; Wendt, Judy K; Visser, Leo G

    2011-01-01

    Despite significant morbidity and mortality among business travelers due to malaria, very little has been published on knowledge, attitudes, and practices (KAP) toward malaria risk. The aim of this study was to assess KAP among frequent international business travelers (FBT) and to identify recommendations for improving malaria prevention that could be applied to the wider FBT community in occupational health. A retrospective web-based survey was conducted in 2005 among self-registered FBT of an oil and gas company based in the Netherlands. The survey was completed by 328 of the 608 self-registered FBT (54%). Fifty-four percent of respondents had visited a high-risk area for malaria. Most respondents (96%) were experienced travelers; the majority (71%) sought health advice before their trip and made use of a company health resource. Fever was recognized as a malaria symptom by all FBT; travel to high-risk malaria areas was correctly identified by 96%, and 99% of these travelers adhered to use of adequate personal protective measures. The proportion of travelers carrying appropriate anti-malaria drug regimen was positively associated with receiving company advice among FBT traveling to high-risk destinations (RR = 2.10, 95% CI: 1.21-3.67), but not for those traveling to low- or no-risk destinations. Only 8% (14) of those going to a high-risk area were not carrying malaria prophylaxis. One in five of FBT traveling to no-risk areas were unnecessarily carrying malaria prophylaxis. The majority of KAP results were excellent. We postulate that a company culture with a strong focus on health, safety, security, and environment can positively contribute to high KAP scores. Notwithstanding the excellent findings, this study also provides a cautionary tale for company health functions against overprescribing of malaria prophylaxis. It demonstrates the need for constant review and audit of adherence to quality criteria. © 2011 International Society of Travel Medicine.

  18. Malaria risk factors in North West Tanzania: the effect of spraying, nets and wealth.

    PubMed

    West, Philippa A; Protopopoff, Natacha; Rowland, Mark; Cumming, Emma; Rand, Alison; Drakeley, Chris; Wright, Alexandra; Kivaju, Zuhura; Kirby, Matthew J; Mosha, Franklin W; Kisinza, William; Kleinschmidt, Immo

    2013-01-01

    Malaria prevalence remains high in many African countries despite massive scaling-up of insecticide treated nets (ITN) and indoor residual spraying (IRS). This paper evaluates the protective effect of pyrethroid IRS and ITNs in relation to risk factors for malaria based on a study conducted in North-West Tanzania, where IRS has been conducted since 2007 and universal coverage of ITNs has been carried out recently. In 2011 community-based cross-sectional surveys were conducted in the two main malaria transmission periods that occur after the short and long rainy seasons. These included 5,152 and 4,325 children aged 0.5-14 years, respectively. Data on IRS and ITN coverage, household demographics and socio-economic status were collected using an adapted version of the Malaria Indicator Survey. Children were screened for malaria by rapid diagnostic test. In the second survey, haemoglobin density was measured and filter paper blood spots were collected to determine age-specific sero-prevalence in each community surveyed. Plasmodium falciparum infection prevalence in children 0.5-14 years old was 9.3% (95%CI:5.9-14.5) and 22.8% (95%CI:17.3-29.4) in the two surveys. Risk factors for infection after the short rains included households not being sprayed (OR = 0.39; 95%CI:0.20-0.75); low community net ownership (OR = 0.45; 95%CI:0.21-0.95); and low community SES (least poor vs. poorest tertile: OR = 0.13, 95%CI:0.05-0.34). Risk factors after the long rains included household poverty (per quintile increase: OR = 0.89; 95%CI:0.82-0.97) and community poverty (least poor vs. poorest tertile: OR = 0.26, 95%CI:0.15-0.44); household IRS or high community ITN ownership were not protective. Despite high IRS coverage and equitable LLIN distribution, poverty was an important risk factor for malaria suggesting it could be beneficial to target additional malaria control activities to poor households and communities. High malaria prevalence in some clusters and the

  19. Malaria Risk Factors in North West Tanzania: The Effect of Spraying, Nets and Wealth

    PubMed Central

    West, Philippa A.; Protopopoff, Natacha; Rowland, Mark; Cumming, Emma; Rand, Alison; Drakeley, Chris; Wright, Alexandra; Kivaju, Zuhura; Kirby, Matthew J.; Mosha, Franklin W.; Kisinza, William; Kleinschmidt, Immo

    2013-01-01

    Malaria prevalence remains high in many African countries despite massive scaling-up of insecticide treated nets (ITN) and indoor residual spraying (IRS). This paper evaluates the protective effect of pyrethroid IRS and ITNs in relation to risk factors for malaria based on a study conducted in North-West Tanzania, where IRS has been conducted since 2007 and universal coverage of ITNs has been carried out recently. In 2011 community-based cross-sectional surveys were conducted in the two main malaria transmission periods that occur after the short and long rainy seasons. These included 5,152 and 4,325 children aged 0.5–14 years, respectively. Data on IRS and ITN coverage, household demographics and socio-economic status were collected using an adapted version of the Malaria Indicator Survey. Children were screened for malaria by rapid diagnostic test. In the second survey, haemoglobin density was measured and filter paper blood spots were collected to determine age-specific sero-prevalence in each community surveyed. Plasmodium falciparum infection prevalence in children 0.5–14 years old was 9.3% (95%CI:5.9–14.5) and 22.8% (95%CI:17.3–29.4) in the two surveys. Risk factors for infection after the short rains included households not being sprayed (OR = 0.39; 95%CI:0.20–0.75); low community net ownership (OR = 0.45; 95%CI:0.21–0.95); and low community SES (least poor vs. poorest tertile: OR = 0.13, 95%CI:0.05–0.34). Risk factors after the long rains included household poverty (per quintile increase: OR = 0.89; 95%CI:0.82–0.97) and community poverty (least poor vs. poorest tertile: OR = 0.26, 95%CI:0.15–0.44); household IRS or high community ITN ownership were not protective. Despite high IRS coverage and equitable LLIN distribution, poverty was an important risk factor for malaria suggesting it could be beneficial to target additional malaria control activities to poor households and communities. High malaria prevalence in some

  20. Malaria in Hadhramout, a southeast province of Yemen: prevalence, risk factors, knowledge, attitude and practices (KAPs).

    PubMed

    Bamaga, Omar A A; Mahdy, Mohammed A K; Mahmud, Rohela; Lim, Yvonne A L

    2014-07-29

    Yemen is a Mediterranean country where 65% of its population is at risk of malaria, with 43% at high risk. Yemen is still in the control phase without sustainable reduction in the proportion of malaria cases. A cross-sectional household survey was carried out in different districts in the southeast of the country to determine malaria prevalence and identify factors that impede progress of the elimination phase. Blood specimens were collected from 735 individuals aged 1-66 years. Plasmodium species were detected and identified by microscopic examination of Giemsa-stained thick and thin blood smears. A household-based questionnaire was used to collect demographic, socioeconomic and environmental data. The overall prevalence of malaria was 18.8% with Plasmodium falciparum as the predominant species (99.3%), with a low rate of Plasmodium vivax detected (0.7%). The infection rate was higher in Al-Raydah and Qusyer districts (21.8%) compared to Hajer district (11.8%). Fifty-two percent of the persons positive for Plasmodium were asymptomatic with low parasite density. The adults had a higher infection rate as compared to children. Univariate analysis identified those whose household's head are fishermen (OR = 11.3, 95% CI: 3.13-40.5) and farmers (OR = 4.84, 95% CI: 1.73-13.6) as high-risk groups. A higher number of positive smears were observed in people living in houses with uncemented brick walls (OR = 2.1, 95% CI: 1.32-3.30), without access to toilets (OR = 1.6, 95% CI: 1.05-2.32), without a fridge (OR = 1. 6, 95% CI: 1.05-2.30), or without TV (OR = 1. 6, (95% CI: 1.05-2.30). People living in houses with water collection points located less than 200 meters away were also at higher risk of acquiring malaria (OR = 1.6, 95% CI: 1.05-2.30). Knowledge about the importance of using insecticide-treated mosquito nets (ITNs) and indoor residual spraying (IRS) for prevention of malaria was 7% and 2%, respectively. Several environmental, socioeconomic

  1. Ranking and prioritization of environmental risks of pharmaceuticals in surface waters.

    PubMed

    Sanderson, Hans; Johnson, David J; Reitsma, Tamara; Brain, Richard A; Wilson, Christian J; Solomon, Keith R

    2004-04-01

    Pharmaceuticals have been reported in surface waters, prompting legitimate public concern, as pharmaceuticals are biologically active compounds used daily by the public. Currently there are ecotoxicological data available for <1%, thus, the European Union Commission's Scientific committee on Toxicity, Ecotoxicity, and Environment (CSTEE) recommended use of (Q)SAR models and precaution to prioritize further risk assessment of approximately 4500 compounds and their adjuvants. We ranked 2986 different pharmaceutical compounds in 51 classes relative to hazard toward algae, daphnids, and fish using the EPIWIN program. This ranking cannot be used to acquit a compound based on predicted relative ranking. Modifying additives were the most toxic classes. Cardiovascular, gastrointestinal, antiviral, anxiolytic sedatives hypnotics and antipsychotics, corticosteroid, and thyroid pharmaceuticals were the predicted most hazardous therapeutic classes. The overall relative order of susceptibility was estimated to be daphnids > fish > algae. Expert judgment is needed to assess specific hazards for classes like microbial resistance and antibiotics, sex hormones, and endocrine disruptors. As human health and the function of ecological systems are interconnected and subject to the precautionary principle, harmonization of evidence for correlation and causality of adverse effects seems sensible in an ethical and cost-effective context to facilitate substitution of hazardous compounds. Data available: http://www.uoguelph.ca/~hsander/.

  2. Modeling spatial variation in risk of presence and insecticide resistance for malaria vectors in Laos.

    PubMed

    Souris, Marc; Marcombe, Sébastien; Laforet, Julie; Brey, Paul T; Corbel, Vincent; Overgaard, Hans J

    2017-01-01

    Climatic, sociological and environmental conditions are known to affect the spatial distribution of malaria vectors and disease transmission. Intensive use of insecticides in the agricultural and public health sectors exerts a strong selective pressure on resistance genes in malaria vectors. Spatio-temporal models of favorable conditions for Anopheles species' presence were developed to estimate the probability of presence of malaria vectors and insecticide resistance in Lao PDR. These models were based on environmental and meteorological conditions, and demographic factors. GIS software was used to build and manage a spatial database with data collected from various geographic information providers. GIS was also used to build and run the models. Results showed that potential insecticide use and therefore the probability of resistance to insecticide is greater in the southwestern part of the country, specifically in Champasack province and where malaria incidence is already known to be high. These findings can help national authorities to implement targeted and effective vector control strategies for malaria prevention and elimination among populations most at risk. Results can also be used to focus the insecticide resistance surveillance in Anopheles mosquito populations in more restricted area, reducing the area of surveys, and making the implementation of surveillance system for Anopheles mosquito insecticide resistance possible.

  3. Modeling spatial variation in risk of presence and insecticide resistance for malaria vectors in Laos

    PubMed Central

    Marcombe, Sébastien; Laforet, Julie; Brey, Paul T.; Corbel, Vincent; Overgaard, Hans J.

    2017-01-01

    Climatic, sociological and environmental conditions are known to affect the spatial distribution of malaria vectors and disease transmission. Intensive use of insecticides in the agricultural and public health sectors exerts a strong selective pressure on resistance genes in malaria vectors. Spatio-temporal models of favorable conditions for Anopheles species’ presence were developed to estimate the probability of presence of malaria vectors and insecticide resistance in Lao PDR. These models were based on environmental and meteorological conditions, and demographic factors. GIS software was used to build and manage a spatial database with data collected from various geographic information providers. GIS was also used to build and run the models. Results showed that potential insecticide use and therefore the probability of resistance to insecticide is greater in the southwestern part of the country, specifically in Champasack province and where malaria incidence is already known to be high. These findings can help national authorities to implement targeted and effective vector control strategies for malaria prevention and elimination among populations most at risk. Results can also be used to focus the insecticide resistance surveillance in Anopheles mosquito populations in more restricted area, reducing the area of surveys, and making the implementation of surveillance system for Anopheles mosquito insecticide resistance possible. PMID:28494013

  4. RAMPART (TM): Risk Assessment Method-Property Analysis and Ranking Tool v.4.0

    SciTech Connect

    Carson, Susan D.; Hunter, Regina L.; Link, Madison D.; Browitt, Robert D.

    2007-09-30

    RAMPART{trademark}, Risk Assessment Method-property Analysis and Ranking Tool, is a new type of computer software package for the assessment of risk to buildings. RAMPART{trademark} has been developed by Sandia National Laboratories (SNL) for the U.S. General Services Administration (GSA). RAMPART {trademark} has been designed and developed to be a risk-based decision support tool that requires no risk analysis expertise on the part of the user. The RAMPART{trademark} user interface elicits information from the user about the building. The RAMPART{trademark} expert system is a set of rules that embodies GSA corporate knowledge and SNL's risk assessment experience. The RAMPART{trademark} database contains both data entered by the user during a building analysis session and large sets of natural hazard and crime data. RAMPART{trademark} algorithms use these data to assess the risk associated with a given building in the face of certain hazards. Risks arising from five natural hazards (earthquake, hurricane, winter storm, tornado and flood); crime (inside and outside the building); fire and terrorism are calculated. These hazards may cause losses of various kinds. RAMPART{trademark} considers death, injury, loss of mission, loss of property, loss of contents, loss of building use, and first-responder loss. The results of each analysis are presented graphically on the screen and in a written report.

  5. Epistasis between the haptoglobin common variant and α+thalassemia influences risk of severe malaria in Kenyan children

    PubMed Central

    Uyoga, Sophie M.; Nyatichi, Emily; Macharia, Alex W.; Nyutu, Gideon; Ndila, Carolyne; Kwiatkowski, Dominic P.; Rockett, Kirk A.; Williams, Thomas N.

    2014-01-01

    Haptoglobin (Hp) scavenges free hemoglobin following malaria-induced hemolysis. Few studies have investigated the relationship between the common Hp variants and the risk of severe malaria, and their results are inconclusive. We conducted a case-control study of 996 children with severe Plasmodium falciparum malaria and 1220 community controls and genotyped for Hp, hemoglobin (Hb) S heterozygotes, and α+thalassemia. Hb S heterozygotes and α+thalassemia homozygotes were protected from severe malaria (odds ratio [OR], 0.12; 95% confidence interval [CI], 0.07-0.18 and OR, 0.69; 95% CI, 0.53-0.91, respectively). The risk of severe malaria also varied by Hp genotype: Hp2-1 was associated with the greatest protection against severe malaria and Hp2-2 with the greatest risk. Meta-analysis of the current and published studies suggests that Hp2-2 is associated with increased risk of severe malaria compared with Hp2-1. We found a significant interaction between Hp genotype and α+thalassemia in predicting risk of severe malaria: Hp2-1 in combination with heterozygous or homozygous α+thalassemia was associated with protection from severe malaria (OR, 0.73; 95% CI, 0.54-0.99 and OR, 0.48; 95% CI, 0.32-0.73, respectively), but α+thalassemia in combination with Hp2-2 was not protective. This epistatic interaction together with varying frequencies of α+thalassemia across Africa may explain the inconsistent relationship between Hp genotype and malaria reported in previous studies. PMID:24478401

  6. Spatial modelling and risk factors of malaria incidence in northern Malawi.

    PubMed

    Kazembe, Lawrence N

    2007-05-01

    Identifying areas of high risk is crucial for providing targeted antimalarial interventions. This study used ecological spatial regression models to profile spatial variation of malaria risk and analysed possible association of disease risk with environmental factors at sub-district level in northern Malawi. Using malaria incidence data collected between January 2002 and December 2003, we applied and compared Bayesian Poisson regression models assuming different spatial structures. For each model we adjusted for environmental covariates initially identified through bivariate non-spatial models. The model with both spatially structured and unstructured heterogeneity provided a better fit, guided by the model comparison criteria. Malaria incidence was associated with altitude, precipitation and soil water holding capacity. The risk increased with altitude (relative risk (RR): 1.092, 95% interval: 1.020, 1.169) and precipitation (RR: 1.031, 95% interval: 0.950, 1.120). At medium level of SWHC relative to low level, the risk was reduced (RR: 0.521, 95% interval: 0.298, 0.912), while at high level of SWHC relative to low level the risk was raised (RR: 1.649, 95% interval: 1.041, 2.612). Compared to the commonly used standardised incidence ratios, the model-based approach provided homogenous and easy to interpret risk estimates. Generally, the smoothed map showed less spatial variation in risk, with slightly higher estimates of malaria risk (RR>1) in low-lying areas mostly situated along the lakeshore regions, in particular in Karonga and Nkhatabay districts, and low risk (RR<1) in high-lying areas along Nyika plateau and Vwaza highlands. The results suggest that the spatial variation in malaria risk in the region is a combination of various environmental factors, both observed and unobserved, and the map only highlights the overall effect of these factors. The results also identified areas of increased risk, where further epidemiological investigations can be carried

  7. Incorporating linguistic, probabilistic, and possibilistic information in a risk-based approach for ranking contaminated sites.

    PubMed

    Zhang, Kejiang; Achari, Gopal; Pei, Yuansheng

    2010-10-01

    Different types of uncertain information-linguistic, probabilistic, and possibilistic-exist in site characterization. Their representation and propagation significantly influence the management of contaminated sites. In the absence of a framework with which to properly represent and integrate these quantitative and qualitative inputs together, decision makers cannot fully take advantage of the available and necessary information to identify all the plausible alternatives. A systematic methodology was developed in the present work to incorporate linguistic, probabilistic, and possibilistic information into the Preference Ranking Organization METHod for Enrichment Evaluation (PROMETHEE), a subgroup of Multi-Criteria Decision Analysis (MCDA) methods for ranking contaminated sites. The identification of criteria based on the paradigm of comparative risk assessment provides a rationale for risk-based prioritization. Uncertain linguistic, probabilistic, and possibilistic information identified in characterizing contaminated sites can be properly represented as numerical values, intervals, probability distributions, and fuzzy sets or possibility distributions, and linguistic variables according to their nature. These different kinds of representation are first transformed into a 2-tuple linguistic representation domain. The propagation of hybrid uncertainties is then carried out in the same domain. This methodology can use the original site information directly as much as possible. The case study shows that this systematic methodology provides more reasonable results. © 2010 SETAC.

  8. Mapping the receptivity of malaria risk to plan the future of control in Somalia

    PubMed Central

    Alegana, Victor Adagi; Patil, Anand Prabhakar; Moloney, Grainne; Borle, Mohammed; Yusuf, Fahmi; Amran, Jamal; Snow, Robert William

    2012-01-01

    Objectives To measure the receptive risks of malaria in Somalia and compare decisions on intervention scale-up based on this map and the more widely used contemporary risk maps. Design Cross-sectional community Plasmodium falciparum parasite rate (PfPR) data for the period 2007–2010 corrected to a standard age range of 2 to <10 years (PfPR2–10) and used within a Bayesian space–time geostatistical framework to predict the contemporary (2010) mean PfPR2–10 and the maximum annual mean PfPR2–10 (receptive) from the highest predicted PfPR2–10 value over the study period as an estimate of receptivity. Setting Randomly sampled communities in Somalia. Participants Randomly sampled individuals of all ages. Main outcome measure Cartographic descriptions of malaria receptivity and contemporary risks in Somalia at the district level. Results The contemporary annual PfPR2–10 map estimated that all districts (n=74) and population (n=8.4 million) in Somalia were under hypoendemic transmission (≤10% PfPR2–10). Of these, 23% of the districts, home to 13% of the population, were under transmission of <1% PfPR2–10. About 58% of the districts and 55% of the population were in the risk class of 1% to <5% PfPR2–10. In contrast, the receptivity map estimated 65% of the districts and 69% of the population were under mesoendemic transmission (>10%–50% PfPR2–10) and the rest as hypoendemic. Conclusion Compared with maps of receptive risks, contemporary maps of transmission mask disparities of malaria risk necessary to prioritise and sustain future control. As malaria risk declines across Africa, efforts must be invested in measuring receptivity for efficient control planning. PMID:22855625

  9. DebtRank: Too Central to Fail? Financial Networks, the FED and Systemic Risk

    NASA Astrophysics Data System (ADS)

    Battiston, Stefano; Puliga, Michelangelo; Kaushik, Rahul; Tasca, Paolo; Caldarelli, Guido

    2012-08-01

    Systemic risk, here meant as the risk of default of a large portion of the financial system, depends on the network of financial exposures among institutions. However, there is no widely accepted methodology to determine the systemically important nodes in a network. To fill this gap, we introduce, DebtRank, a novel measure of systemic impact inspired by feedback-centrality. As an application, we analyse a new and unique dataset on the USD 1.2 trillion FED emergency loans program to global financial institutions during 2008-2010. We find that a group of 22 institutions, which received most of the funds, form a strongly connected graph where each of the nodes becomes systemically important at the peak of the crisis. Moreover, a systemic default could have been triggered even by small dispersed shocks. The results suggest that the debate on too-big-to-fail institutions should include the even more serious issue of too-central-to-fail.

  10. Spatial analysis and mapping of malaria risk in Malawi using point-referenced prevalence of infection data.

    PubMed

    Kazembe, Lawrence N; Kleinschmidt, Immo; Holtz, Timothy H; Sharp, Brian L

    2006-09-20

    Current malaria control initiatives aim at reducing malaria burden by half by the year 2010. Effective control requires evidence-based utilisation of resources. Characterizing spatial patterns of risk, through maps, is an important tool to guide control programmes. To this end an analysis was carried out to predict and map malaria risk in Malawi using empirical data with the aim of identifying areas where greatest effort should be focussed. Point-referenced prevalence of infection data for children aged 1-10 years were collected from published and grey literature and geo-referenced. The model-based geostatistical methods were applied to analyze and predict malaria risk in areas where data were not observed. Topographical and climatic covariates were added in the model for risk assessment and improved prediction. A Bayesian approach was used for model fitting and prediction. Bivariate models showed a significant association of malaria risk with elevation, annual maximum temperature, rainfall and potential evapotranspiration (PET). However in the prediction model, the spatial distribution of malaria risk was associated with elevation, and marginally with maximum temperature and PET. The resulting map broadly agreed with expert opinion about the variation of risk in the country, and further showed marked variation even at local level. High risk areas were in the low-lying lake shore regions, while low risk was along the highlands in the country. The map provided an initial description of the geographic variation of malaria risk in Malawi, and might help in the choice and design of interventions, which is crucial for reducing the burden of malaria in Malawi.

  11. Plasmodium genome in blood donors at risk for malaria after several years of residence in Italy.

    PubMed

    Assennato, Sonny Michael; Berzuini, Alessandra; Foglieni, Barbara; Spreafico, Marta; Allain, Jean-Pierre; Prati, Daniele

    2014-10-01

    At present, the main risk of transfusion-transmitted malaria (TTM) in nonendemic countries is chronic, asymptomatic immigrants from malaria-endemic areas. Semi-immune donors may carry undetected parasitemia. This study examines Plasmodium infection in at-risk blood donors in Northern Italy. Plasma samples from 97 candidate donors and 80 controls were tested for malarial antibodies using a commercial enzyme immunoassay. The conserved 18S rRNA and the mitochondrial genes of Plasmodium were amplified to detect and quantify parasite genomes (copies/mL). Plasmodium species were identified with a species-specific nested polymerase chain reaction. Parasitemic samples were further tested by amplification of polymorphic repetitive regions in MSP-1 Block 2, MSP-2 Block 3, and glutamate-rich protein (GLURP) confirmed by sequencing. Three of 83 seropositive (3.6%) and one of 14 seronegative at-risk candidate donors carried Plasmodium genome (4 × 10(3) -8.5 × 10(4) copies/mL): two P. falciparum, one P. malariae (seronegative sample), and one coinfection with P. malariae and P. ovale. Alleles of MSP-1 (MAD20 and K1), MSP-2 (3D7 and FC27), and GLURP were amplified from Sample 261. In Sample 282 only one allele in MSP-2 (FC27) and GLURP was amplified. No alleles were detected in Samples 283 and 331. Immigrants from endemic countries might carry infectious Plasmodium after 2 to 5 years of continuous residence in Italy. Serologic screening may miss donors carrying P. malariae. Permanent exclusion or screening for both antibodies and genome are needed to prevent TTM. © 2014 AABB.

  12. Malaria risk in young male travellers but local transmission persists: a case-control study in low transmission Namibia.

    PubMed

    Smith, Jennifer L; Auala, Joyce; Haindongo, Erastus; Uusiku, Petrina; Gosling, Roly; Kleinschmidt, Immo; Mumbengegwi, Davis; Sturrock, Hugh J W

    2017-02-10

    A key component of malaria elimination campaigns is the identification and targeting of high risk populations. To characterize high risk populations in north central Namibia, a prospective health facility-based case-control study was conducted from December 2012-July 2014. Cases (n = 107) were all patients presenting to any of the 46 health clinics located in the study districts with a confirmed Plasmodium infection by multi-species rapid diagnostic test (RDT). Population controls (n = 679) for each district were RDT negative individuals residing within a household that was randomly selected from a census listing using a two-stage sampling procedure. Demographic, travel, socio-economic, behavioural, climate and vegetation data were also collected. Spatial patterns of malaria risk were analysed. Multivariate logistic regression was used to identify risk factors for malaria. Malaria risk was observed to cluster along the border with Angola, and travel patterns among cases were comparatively restricted to northern Namibia and Angola. Travel to Angola was associated with excessive risk of malaria in males (OR 43.58 95% CI 2.12-896), but there was no corresponding risk associated with travel by females. This is the first study to reveal that gender can modify the effect of travel on risk of malaria. Amongst non-travellers, male gender was also associated with a higher risk of malaria compared with females (OR 1.95 95% CI 1.25-3.04). Other strong risk factors were sleeping away from the household the previous night, lower socioeconomic status, living in an area with moderate vegetation around their house, experiencing moderate rainfall in the month prior to diagnosis and living <15 km from the Angolan border. These findings highlight the critical need to target malaria interventions to young male travellers, who have a disproportionate risk of malaria in northern Namibia, to coordinate cross-border regional malaria prevention initiatives and to scale up coverage of

  13. High dimensional endophenotype ranking in the search for major depression risk genes.

    PubMed

    Glahn, David C; Curran, Joanne E; Winkler, Anderson M; Carless, Melanie A; Kent, Jack W; Charlesworth, Jac C; Johnson, Matthew P; Göring, Harald H H; Cole, Shelley A; Dyer, Thomas D; Moses, Eric K; Olvera, Rene L; Kochunov, Peter; Duggirala, Ravi; Fox, Peter T; Almasy, Laura; Blangero, John

    2012-01-01

    Despite overwhelming evidence that major depression is highly heritable, recent studies have localized only a single depression-related locus reaching genome-wide significance and have yet to identify a causal gene. Focusing on family-based studies of quantitative intermediate phenotypes or endophenotypes, in tandem with studies of unrelated individuals using categorical diagnoses, should improve the likelihood of identifying major depression genes. However, there is currently no empirically derived statistically rigorous method for selecting optimal endophentypes for mental illnesses. Here, we describe the endophenotype ranking value, a new objective index of the genetic utility of endophenotypes for any heritable illness. Applying endophenotype ranking value analysis to a high-dimensional set of over 11,000 traits drawn from behavioral/neurocognitive, neuroanatomic, and transcriptomic phenotypic domains, we identified a set of objective endophenotypes for recurrent major depression in a sample of Mexican American individuals (n = 1122) from large randomly selected extended pedigrees. Top-ranked endophenotypes included the Beck Depression Inventory, bilateral ventral diencephalon volume, and expression levels of the RNF123 transcript. To illustrate the utility of endophentypes in this context, each of these traits were utlized along with disease status in bivariate linkage analysis. A genome-wide significant quantitative trait locus was localized on chromsome 4p15 (logarithm of odds = 3.5) exhibiting pleiotropic effects on both the endophenotype (lymphocyte-derived expression levels of the RNF123 gene) and disease risk. The wider use of quantitative endophenotypes, combined with unbiased methods for selecting among these measures, should spur new insights into the biological mechanisms that influence mental illnesses like major depression. Copyright © 2012 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  14. Oil spill risk assessment model and the ranking of ports for oil spill vulnerability. Final report

    SciTech Connect

    Raj, P.K.; Turner, C.K.

    1995-06-01

    The U.S. Coast Guard`s Marine Safety Office (MSO) of each port is required to develop contingency plans to respond to oil spills. The contingency plans at present do not use rigorous risk assessment procedures to identify the spectrum of spills that are possible in each port and estimate the frequency of occurrence of different size spills. In order to provide these procedures, there was a need to develop, for use in contingency planning, a uniform guidance methodology based on risk assessment principles. The development of port specific oil spill risk assessment methodology is described in this report. The port model takes into consideration the specifics of the water body in the port, vessel traffic, current or projected oil transport volume into the port per year, size distribution of vessels, as well as the size distribution of the oil carrying vessels (tankers and barges), weather and channel characteristics, etc. The model uses the accident risk factors for a number of U.S. ports developed in the Ports Need (Vessel Traffic Services Benefit) Study and takes into account the reduction in the vessel accident rate due to the provision of vessel traffic management systems. The output from the risk model is a histogram of the frequency of accidents vs the size of potential spill volume. A PC based computer program (`OlLRlSK`) has also been developed to calculate the risk for any port. Using the results, the spill risks in different ports can be compared and the ports ranked based on the susceptibity to small, medium and large spills. The oil spill risk for a number of major U.S. ports has been calculated and presented.

  15. Using risk-ranking of metals to identify which poses the greatest threat to freshwater organisms in the UK.

    PubMed

    Donnachie, Rachel L; Johnson, Andrew C; Moeckel, Claudia; Pereira, M Glória; Sumpter, John P

    2014-11-01

    Freshwater aquatic organisms face the challenge of being exposed to a multitude of chemicals discharged by the human population. The objective of this study was to rank metals according to the threat they pose to aquatic organisms. This will contribute to a wider Chemical Strategy for freshwater which will risk-rank all chemicals based on their potential risk to wildlife in a UK setting. The method involved comparing information on ecotoxicological thresholds with measured concentrations in rivers. The bioconcentration factor was also considered as a ranking method. The metals; Ag, Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn, were analysed using this approach. Triclosan and lindane were used as comparative organic pollutants. Using a range of ranking techniques, Cu, Al and Zn came top of the list of concern, with Cu coming first.

  16. Elimination of Malaria Risk through Integrated Combination Strategies in a Tropical Military Training Island

    PubMed Central

    Lee, Vernon J.; Ow, Samuel; Heah, Harold; Tan, Meng Yaw; Lam, Patrick; Ng, Lee-Ching; Lam-Phua, Sai Gek; Imran, Abdul Qadir; Seet, Benjamin

    2010-01-01

    On the military training facility of Tekong Island, Singapore, a comprehensive vector-borne disease control program was started in end-2006 to reduce mosquito populations and negate the need for anti-malaria chemoprophylaxis. The program was based on 1) preventing importation of malaria through screening of visitors, 2) preventing human-to-mosquito transmission through early case detection and mosquito control, 3) preventing mosquito-to-human transmission through personal protection, and 4) contingency plans. Systematic environmental works were performed to reduce breeding sites, and insecticide use targeted both adult mosquitoes and larvae. Mosquito populations declined from 103 mosquitoes per sampling site in January 2007 to 6 per site by March 2007 (P < 0.001). The proportion of positive ovitraps declined from 93% in January 2007–2% in March 2007 (P < 0.001). There were no malaria cases on the island despite chemoprophylaxis termination, showing that comprehensive combination vector-control strategies were effective in reducing the risk of malaria. PMID:20519595

  17. Risk of malaria reemergence in southern France: testing scenarios with a multiagent simulation model.

    PubMed

    Linard, Catherine; Ponçon, Nicolas; Fontenille, Didier; Lambin, Eric F

    2009-03-01

    The Camargue, a region in southern France, is considered a potential site for malaria reemergence. All the suitable factors of the disease transmission system are present -- competent mosquito vectors, habitats for their breeding, and susceptible people -- except for the parasite. The objective of this study was to test potential drivers of malaria reemergence in this system after possible changes in biological attributes of vectors, agricultural practices, land use, tourism activities, and climate. Scenarios of plausible futures were formulated and then simulated using a spatially explicit and dynamic multiagent simulation: the MALCAM model. Scenarios were developed by varying the value of model inputs. Model outputs were compared based on the contact rate between people and potential malaria vectors, and the number of new infections in case of reintroduction of the parasite in the region. Model simulations showed that the risk of malaria reemergence is low in the Camargue. If the disease would reemerge, it would be the result of a combination of unfavorable conditions: introduction of a large population of infectious people or mosquitoes, combined with high levels of people-vector contacts resulting from significant changes in land use, tourism activities, agricultural policies, biological evolution of mosquitoes, and climate changes. The representation in the MALCAM model of interactions and feedbacks between different agents, and between agents and their environment, led in some cases to counterintuitive results. Results from scenario analyses can help local public health authorities in policy formulation.

  18. Elimination of malaria risk through integrated combination strategies in a tropical military training island.

    PubMed

    Lee, Vernon J; Ow, Samuel; Heah, Harold; Tan, Meng Yaw; Lam, Patrick; Ng, Lee-Ching; Lam-Phua, Sai Gek; Imran, Abdul Qadir; Seet, Benjamin

    2010-06-01

    On the military training facility of Tekong Island, Singapore, a comprehensive vector-borne disease control program was started in end-2006 to reduce mosquito populations and negate the need for anti-malaria chemoprophylaxis. The program was based on 1) preventing importation of malaria through screening of visitors, 2) preventing human-to-mosquito transmission through early case detection and mosquito control, 3) preventing mosquito-to-human transmission through personal protection, and 4) contingency plans. Systematic environmental works were performed to reduce breeding sites, and insecticide use targeted both adult mosquitoes and larvae. Mosquito populations declined from 103 mosquitoes per sampling site in January 2007 to 6 per site by March 2007 (P < 0.001). The proportion of positive ovitraps declined from 93% in January 2007-2% in March 2007 (P < 0.001). There were no malaria cases on the island despite chemoprophylaxis termination, showing that comprehensive combination vector-control strategies were effective in reducing the risk of malaria.

  19. A Simple Model to Rank Shellfish Farming Areas Based on the Risk of Disease Introduction and Spread.

    PubMed

    Thrush, M A; Pearce, F M; Gubbins, M J; Oidtmann, B C; Peeler, E J

    2016-03-09

    The European Union Council Directive 2006/88/EC requires that risk-based surveillance (RBS) for listed aquatic animal diseases is applied to all aquaculture production businesses. The principle behind this is the efficient use of resources directed towards high-risk farm categories, animal types and geographic areas. To achieve this requirement, fish and shellfish farms must be ranked according to their risk of disease introduction and spread. We present a method to risk rank shellfish farming areas based on the risk of disease introduction and spread and demonstrate how the approach was applied in 45 shellfish farming areas in England and Wales. Ten parameters were used to inform the risk model, which were grouped into four risk themes based on related pathways for transmission of pathogens: (i) live animal movement, (ii) transmission via water, (iii) short distance mechanical spread (birds) and (iv) long distance mechanical spread (vessels). Weights (informed by expert knowledge) were applied both to individual parameters and to risk themes for introduction and spread to reflect their relative importance. A spreadsheet model was developed to determine quantitative scores for the risk of pathogen introduction and risk of pathogen spread for each shellfish farming area. These scores were used to independently rank areas for risk of introduction and for risk of spread. Thresholds were set to establish risk categories (low, medium and high) for introduction and spread based on risk scores. Risk categories for introduction and spread for each area were combined to provide overall risk categories to inform a risk-based surveillance programme directed at the area level. Applying the combined risk category designation framework for risk of introduction and spread suggested by European Commission guidance for risk-based surveillance, 4, 10 and 31 areas were classified as high, medium and low risk, respectively.

  20. Duration of residency in a non-endemic area and risk of severe malaria in African immigrants.

    PubMed

    Färnert, A; Wyss, K; Dashti, S; Naucler, P

    2015-05-01

    In malaria-endemic areas, adults very rarely succumb to severe malaria, suggesting that immunity to severe disease is life-long under conditions of repeated exposure. To what extent this protection persists in the absence of exposure remains to be established. The aim of this study was to assess whether duration of residency in a malaria-free country affects the risk for severe malaria in immigrants originating from sub-Saharan Africa. We conducted a retrospective chart review of 948 cases of malaria diagnosed in Stockholm, Sweden in 1995-2013. Among 501 adult patients with Plasmodium falciparum (315 of endemic origin and 186 of non-endemic origin, mainly Sweden), 41 (8.2%) had severe malaria according to WHO criteria (including 5% with parasitaemia), 22 (4.4%) had factors prognostic of poor outcome, and 35 (7.0%) were admitted to intensive care. Overall, patient origin did not affect the odds of severe malaria, according to any of these definitions. However, when the immigrants were stratified with regard to their duration of residency in Sweden, the risk of factors prognostic for poor outcome was associated with duration of prior residency in a malaria-free country among patients of endemic origin (p 0.02), and immigrants who had lived for ≥ 15 years in Sweden had a similar risk as non-immune travellers. The results of this explorative study suggest that, although immunity to severe malaria is maintained for several years in African adults, this protection might be lost with time without repeated re-exposure. A larger study, preferably including multiple centres, will be needed to confirm our findings.

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

    PubMed Central

    2012-01-01

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

  2. Using a new high resolution regional model for malaria that accounts for population density and surface hydrology to determine sensitivity of malaria risk to climate drivers

    NASA Astrophysics Data System (ADS)

    Tompkins, Adrian; Ermert, Volker; Di Giuseppe, Francesca

    2013-04-01

    In order to better address the role of population dynamics and surface hydrology in the assessment of malaria risk, a new dynamical disease model been developed at ICTP, known as VECTRI: VECtor borne disease community model of ICTP, TRIeste (VECTRI). The model accounts for the temperature impact on the larvae, parasite and adult vector populations. Local host population density affects the transmission intensity, and the model thus reproduces the differences between peri-urban and rural transmission noted in Africa. A new simple pond model framework represents surface hydrology. The model can be used on with spatial resolutions finer than 10km to resolve individual health districts and thus can be used as a planning tool. Results of the models representation of interannual variability and longer term projections of malaria transmission will be shown for Africa. These will show that the model represents the seasonality and spatial variations of malaria transmission well matching a wide range of survey data of parasite rate and entomological inoculation rate (EIR) from across West and East Africa taken in the period prior to large-scale interventions. The model is used to determine the sensitivity of malaria risk to climate variations, both in rainfall and temperature, and then its use in a prototype forecasting system coupled with ECMWF forecasts will be demonstrated.

  3. Integrating rapid risk mapping and mobile phone call record data for strategic malaria elimination planning.

    PubMed

    Tatem, Andrew J; Huang, Zhuojie; Narib, Clothilde; Kumar, Udayan; Kandula, Deepika; Pindolia, Deepa K; Smith, David L; Cohen, Justin M; Graupe, Bonita; Uusiku, Petrina; Lourenço, Christopher

    2014-02-10

    As successful malaria control programmes re-orientate towards elimination, the identification of transmission foci, targeting of attack measures to high-risk areas and management of importation risk become high priorities. When resources are limited and transmission is varying seasonally, approaches that can rapidly prioritize areas for surveillance and control can be valuable, and the most appropriate attack measure for a particular location is likely to differ depending on whether it exports or imports malaria infections. Here, using the example of Namibia, a method for targeting of interventions using surveillance data, satellite imagery, and mobile phone call records to support elimination planning is described. One year of aggregated movement patterns for over a million people across Namibia are analyzed, and linked with case-based risk maps built on satellite imagery. By combining case-data and movement, the way human population movements connect transmission risk areas is demonstrated. Communities that were strongly connected by relatively higher levels of movement were then identified, and net export and import of travellers and infection risks by region were quantified. These maps can aid the design of targeted interventions to maximally reduce the number of cases exported to other regions while employing appropriate interventions to manage risk in places that import them. The approaches presented can be rapidly updated and used to identify where active surveillance for both local and imported cases should be increased, which regions would benefit from coordinating efforts, and how spatially progressive elimination plans can be designed. With improvements in surveillance systems linked to improved diagnosis of malaria, detailed satellite imagery being readily available and mobile phone usage data continually being collected by network providers, the potential exists to make operational use of such valuable, complimentary and contemporary datasets on an

  4. Integrating rapid risk mapping and mobile phone call record data for strategic malaria elimination planning

    PubMed Central

    2014-01-01

    Background As successful malaria control programmes re-orientate towards elimination, the identification of transmission foci, targeting of attack measures to high-risk areas and management of importation risk become high priorities. When resources are limited and transmission is varying seasonally, approaches that can rapidly prioritize areas for surveillance and control can be valuable, and the most appropriate attack measure for a particular location is likely to differ depending on whether it exports or imports malaria infections. Methods/Results Here, using the example of Namibia, a method for targeting of interventions using surveillance data, satellite imagery, and mobile phone call records to support elimination planning is described. One year of aggregated movement patterns for over a million people across Namibia are analyzed, and linked with case-based risk maps built on satellite imagery. By combining case-data and movement, the way human population movements connect transmission risk areas is demonstrated. Communities that were strongly connected by relatively higher levels of movement were then identified, and net export and import of travellers and infection risks by region were quantified. These maps can aid the design of targeted interventions to maximally reduce the number of cases exported to other regions while employing appropriate interventions to manage risk in places that import them. Conclusions The approaches presented can be rapidly updated and used to identify where active surveillance for both local and imported cases should be increased, which regions would benefit from coordinating efforts, and how spatially progressive elimination plans can be designed. With improvements in surveillance systems linked to improved diagnosis of malaria, detailed satellite imagery being readily available and mobile phone usage data continually being collected by network providers, the potential exists to make operational use of such valuable

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

    PubMed Central

    2011-01-01

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

  6. DebtRank: Too Central to Fail? Financial Networks, the FED and Systemic Risk

    PubMed Central

    Battiston, Stefano; Puliga, Michelangelo; Kaushik, Rahul; Tasca, Paolo; Caldarelli, Guido

    2012-01-01

    Systemic risk, here meant as the risk of default of a large portion of the financial system, depends on the network of financial exposures among institutions. However, there is no widely accepted methodology to determine the systemically important nodes in a network. To fill this gap, we introduce, DebtRank, a novel measure of systemic impact inspired by feedback-centrality. As an application, we analyse a new and unique dataset on the USD 1.2 trillion FED emergency loans program to global financial institutions during 2008–2010. We find that a group of 22 institutions, which received most of the funds, form a strongly connected graph where each of the nodes becomes systemically important at the peak of the crisis. Moreover, a systemic default could have been triggered even by small dispersed shocks. The results suggest that the debate on too-big-to-fail institutions should include the even more serious issue of too-central-to-fail. PMID:22870377

  7. Risk factors and outcomes stratified by severity of acute kidney injury in malaria.

    PubMed

    Saravu, Kavitha; Rishikesh, Kumar; Parikh, Chirag R

    2014-01-01

    Severe acute kidney injury (AKI) is known to have prognostic value for in-hospital outcomes in malaria. However, little is known about the association of AKI of lesser severity with malarial risk factors and outcomes--and such a gap is becoming increasingly relevant with the upsurge in the incidence of AKI due to Plasmodium falciparum malaria and Plasmodium vivax malaria over the last decade. We aimed to identify risk factors of AKI in malaria and assessed in-hospital outcomes stratified by severity of AKI. We performed an observational study of 1,191 hospitalized malaria patients enrolled between 2007 and 2011 in a tertiary care academic center in India. Patients were categorized based on peak serum creatinine into one of three groups: no AKI (<1.6 mg/dL), mild AKI (1.6-3.0 mg/dL), and severe AKI (>3 mg/dL). Plasmodium vivax was the predominant species (61.41%), followed by Plasmodium falciparum (36.41%) and mixed infections with both the species (2.18%). Mild and severe AKI were detected in 12% and 5.6% of patients, respectively. Mild AKI due to Plasmodium vivax (49%) and Plasmodium falciparum (48.5%) was distributed relatively equally within the sample population; however, cases of severe AKI due to Plasmodium falciparum (80%) and Plasmodium vivax (13%) was significantly different (P<0.001). On history and physical examination, risk factors for AKI were age, absence of fever, higher heart rate, lower diastolic blood pressure, icterus, and hepatomegaly. The only laboratory parameter associated with risk of AKI on multivariate analysis was direct bilirubin. Patients with mild and severe AKI had greater organ complications, supportive requirements, longer duration of hospital stay and in-hospital mortality in a dose-dependent relationship, than patients with no AKI. Mild AKI is associated with significant (P<0.05) morbidity compared to no AKI, and future studies should assess strategies for early diagnosis of AKI and prevent AKI progression.

  8. Evidence for an increased risk of transmission of simian immunodeficiency virus and malaria in a rhesus macaque coinfection model.

    PubMed

    Trott, Kristin A; Chau, Jennifer Y; Hudgens, Michael G; Fine, Jason; Mfalila, Chelu K; Tarara, Ross P; Collins, William E; Sullivan, Joann; Luckhart, Shirley; Abel, Kristina

    2011-11-01

    In sub-Saharan Africa, HIV-1 infection frequently occurs in the context of other coinfecting pathogens, most importantly, Mycobacterium tuberculosis and malaria parasites. The consequences are often devastating, resulting in enhanced morbidity and mortality. Due to the large number of confounding factors influencing pathogenesis in coinfected people, we sought to develop a nonhuman primate model of simian immunodeficiency virus (SIV)-malaria coinfection. In sub-Saharan Africa, Plasmodium falciparum is the most common malaria parasite and is responsible for most malaria-induced deaths. The simian malaria parasite Plasmodium fragile can induce clinical symptoms, including cerebral malaria in rhesus macaques, that resemble those of P. falciparum infection in humans. Thus, based on the well-characterized rhesus macaque model of SIV infection, this study reports the development of a novel rhesus macaque SIV-P. fragile coinfection model to study human HIV-P. falciparum coinfection. Using this model, we show that coinfection is associated with an increased, although transient, risk of both HIV and malaria transmission. Specifically, SIV-P. fragile coinfected macaques experienced an increase in SIV viremia that was temporarily associated with an increase in potential SIV target cells and systemic immune activation during acute parasitemia. Conversely, primary parasitemia in SIV-P. fragile coinfected animals resulted in higher gametocytemia that subsequently translated into higher oocyst development in mosquitoes. To our knowledge, this is the first animal model able to recapitulate the increased transmission risk of both HIV and malaria in coinfected humans. Therefore, this model could serve as an essential tool to elucidate distinct immunological, virological, and/or parasitological parameters underlying disease exacerbation in HIV-malaria coinfected people.

  9. Identification of risk factors for malaria control by focused interventions in Ranchi district, Jharkhand, India.

    PubMed

    Saxena, Rekha; Das, M K; Nagpal, B N; Srivastava, Aruna; Gupta, Sanjeev Kumar; Kumar, Anil; Tomar, Arvind Singh; Sinha, A T S; Vidyotma, Rajkumari; Jeyaseelan, A T; Baraik, Vijay Kumar; Singh, V P

    2014-12-01

    Ranchi, the capital of Jharkhand state is endemic for malaria, particularly the Bundu Primary Health Centre (PHC) is the worst affected. Therefore, a study was initiated during 2009 using remote sensing (RS) and geographical information system (GIS) to identify risk factors responsible for high endemicity in this PHC. Bundu and Angara in Ranchi district were identified as high and low malaria endemic PHCs based on epidemiological data of three years (2007-09). The habitation, streams, other water body, landform, PHC and village boundary thematic maps were prepared using IRS-P6/LISS III-IV imageries and macro level breeding sites were identified. Digital elevation model (DEM) of the PHCs was generated using Cartosat Stereo Pair images and from DEM, slope map was derived to calculate flat area. From slope, aspect map was derived to indicate direction of water flow. Length of perennial streams, area under rocky terrain and buffer zones of 250, 500 and 750 m were constructed around streams. High resolution remote sensing imageries were used to identify micro level breeding sites. Based on macro-micro breeding sites, six villages from each PHC were selected randomly having combination of different parameters representing all ecotypes. Entomological data were collected during 2010-11 in pre- and post-monsoon seasons following standard techniques and analyzed statistically. Differential analysis was attempted to comprehend socioeconomic and other determinants associated with malaria transmission. The study identified eight risk factors responsible for higher malaria endemicity in Bundu in comparison to Angara PHC based on ecological, entomological, socioeconomic and other local parameters. Focused interventions in integrated vector management (IVM) mode are required to be carried out in the district for better management and control of disease.

  10. [Imported malaria in Tunisia: consequences on the risk of resurgence of the disease].

    PubMed

    Aoun, K; Siala, E; Tchibkere, D; Ben Abdallah, R; Zallagua, N; Chahed, M K; Bouratbine, A

    2010-02-01

    Although malaria has been eradicated in Tunisia since 1979, the disease is still a health issue due to the persistence of mosquitoes and coexistence with a potential parasite reservoir in the form of imported cases. From 1999 to 2006, 98 cases of imported malaria were diagnosed at the Pasteur Institute in Tunis where nearly 30% of national cases are recorded. Tunisians accounted for 24.5% of these cases versus 75.5% involving foreigners. The occurrence rate has steadily increased in volunteer workers, businessmen, diplomats and athletes who together accounted for 41.7% of cases in 1995 as compared to only 17.4% in 1980 (p<0.01). Most cases (96.5%) were imported from sub-Saharan Africa. The most frequent countries involved in importation were Cote d'Ivoire (23 cases) and Mali (8 cases) that are now linked to Tunisia by regular flights. About one third of patients were asymptomatic at the time of diagnosis. This finding underlines the importance of recommending systematic screening in high-risk groups. Fever (70.6%) and gastro-intestinal manifestations (27.9%) were the most frequent clinical findings in the 69 symptomatic cases. Plasmodium falciparum (71.4%) was the most common species followed by Plasmodium ovale (19.4%). Gametocytes were detected in 9.2% of subjects, thus creating a theoretical source of infection for mosquitoes especially since 60.2% of all cases were recorded between June and October when mosquitoes are active in Tunisia. Due to increasing exchange with endemic malaria areas in Africa that has resulted in a higher incidence of imported cases and a futher risk of introduction of tropical mosquito species as well as to global warming that promotes plasmodium transmission, greater vigilance is necessary to ensure eradication of malaria in Tunisia.

  11. Trends in the knowledge, attitudes and practices of travel risk groups towards prevention of malaria: results from the Dutch Schiphol Airport Survey 2002 to 2009

    PubMed Central

    2012-01-01

    Background Previous studies investigating the travellers’ knowledge, attitudes and practices (KAP) profile indicated an important educational need among those travelling to risk destinations. Initiatives to improve such education should target all groups of travellers, including business travellers, those visiting friends and relatives (VFRs), and elderly travellers. Methods In the years 2002 to 2009, a questionnaire-based survey was conducted at the Dutch Schiphol Airport with the aim to study trends in KAP of travel risk groups towards prevention of malaria. The risk groups last-minute travellers, solo-travellers, business travellers, VFRs and elderly travellers were specifically studied. Results A total of 3,045 respondents were included in the survey. Travellers to destinations with a high risk for malaria had significantly more accurate risk perceptions (knowledge) than travellers to low-risk destinations. The relative risk for malaria in travellers to high-risk destinations was probably mitigated by higher protection rates against malaria as compared with travellers to low risk destinations. There were no significant differences in intended risk-taking behaviour. Trend analyses showed a significant change over time in attitude towards more risk-avoiding behaviour and towards higher protection rates against malaria in travellers to high-risk destinations. The KAP profile of last-minute travellers substantially increased their relative risk for malaria, which contrasts to the slight increase in relative risk of solo travellers, business travellers and VFRs for malaria. Conclusions The results of this sequential cohort survey in Dutch travellers suggest an annual 1.8% increase in protection rates against malaria coinciding with an annual 2.5% decrease in intended risk-seeking behaviour. This improvement may reflect the continuous efforts of travel health advice providers to create awareness and to propagate safe and healthy travel. The KAP profile of last

  12. Malaria and blood transfusion: major issues of blood safety in malaria-endemic countries and strategies for mitigating the risk of Plasmodium parasites.

    PubMed

    Abdullah, Saleh; Karunamoorthi, Kaliyaperumal

    2016-01-01

    Malaria inflicts humankind over centuries, and it remains as a major threat to both clinical medicine and public health worldwide. Though hemotherapy is a life-sustaining modality, it continues to be a possible source of disease transmission. Hence, hemovigilance is a matter of grave concern in the malaria-prone third-world countries. In order to pursue an effective research on hemovigilance, a comprehensive search has been conducted by using the premier academic-scientific databases, WHO documents, and English-language search engines. One hundred two appropriate articles were chosen for data extraction, with a particular reference to emerging pathogens transmitted through blood transfusion, specifically malaria. Blood donation screening is done through microscopic examination and immunological assays to improve the safety of blood products by detection major blood-borne pathogens, viz., HIV, HBV, HCV, syphilis, and malarial parasites. Transfusion therapy significantly dwindles the preventable morbidity and mortality attributed to various illnesses and diseases, particularly AIDS, tuberculosis, and malaria. Examination of thick and thin blood smears are performed to detect positivity and to identify the Plasmodium species, respectively. However, all of these existing diagnostic tools have their own limitations in terms of sensitivity, specificity, cost-effectiveness, and lack of resources and skilled personnel. Globally, despite the mandate need of screening blood and its components according to the blood-establishment protocols, it is seldom practiced in the low-income/poverty-stricken settings. In addition, each and every single phase of transfusion chain carries sizable inherent risks from donors to recipients. Interestingly, opportunities also lie ahead to enhance the safety of blood-supply chain and patients. It can be achieved through sustainable blood-management strategies like (1) appropriate usage of precise diagnostic tools/techniques, (2) promoting

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

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  14. Malaria risk factor assessment using active and passive surveillance data from Aceh Besar, Indonesia, a low endemic, malaria elimination setting with Plasmodium knowlesi, Plasmodium vivax, and Plasmodium falciparum.

    PubMed

    Herdiana, Herdiana; Cotter, Chris; Coutrier, Farah N; Zarlinda, Iska; Zelman, Brittany W; Tirta, Yusrifar Kharisma; Greenhouse, Bryan; Gosling, Roly D; Baker, Peter; Whittaker, Maxine; Hsiang, Michelle S

    2016-09-13

    As malaria transmission declines, it becomes more geographically focused and more likely due to asymptomatic and non-falciparum infections. To inform malaria elimination planning in the context of this changing epidemiology, local assessments on the risk factors for malaria infection are necessary, yet challenging due to the low number of malaria cases. A population-based, cross-sectional study was performed using passive and active surveillance data collected in Aceh Besar District, Indonesia from 2014 to 2015. Malaria infection was defined as symptomatic polymerase chain reaction (PCR)-confirmed infection in index cases reported from health facilities, and asymptomatic or symptomatic PCR-confirmed infection identified in reactive case detection (RACD). Potential risk factors for any infection, species-specific infection, or secondary-case detection in RACD were assessed through questionnaires and evaluated for associations. Nineteen Plasmodium knowlesi, 12 Plasmodium vivax and six Plasmodium falciparum cases were identified passively, and 1495 community members screened in RACD, of which six secondary cases were detected (one P. knowlesi, three P. vivax, and two P. falciparum, with four being asymptomatic). Compared to non-infected subjects screened in RACD, cases identified through passive or active surveillance were more likely to be male (AOR 12.5, 95 % CI 3.0-52.1), adult (AOR 14.0, 95 % CI 2.2-89.6 for age 16-45 years compared to <15 years), have visited the forest in the previous month for any reason (AOR 5.6, 95 % CI 1.3-24.2), and have a workplace near or in the forest and requiring overnight stays (AOR 7.9, 95 % CI 1.6-39.7 compared to workplace not near or in the forest). Comparing subjects with infections of different species, differences were observed in sub-district of residence and other demographic and behavioural factors. Among subjects screened in RACD, cases compared to non-cases were more likely to be febrile and reside within 100 m of

  15. Status of insecticide resistance in high-risk malaria provinces in Afghanistan.

    PubMed

    Ahmad, Mushtaq; Buhler, Cyril; Pignatelli, Patricia; Ranson, Hilary; Nahzat, Sami Mohammad; Naseem, Mohammad; Sabawoon, Muhammad Farooq; Siddiqi, Abdul Majeed; Vink, Martijn

    2016-02-18

    Insecticide resistance seriously threatens the efficacy of vector control interventions in malaria endemic countries. In Afghanistan, the status of insecticide resistance is largely unknown while distribution of long-lasting insecticidal nets has intensified in recent years. The main objective of this study was thus to measure the level of resistance to four classes of insecticides in provinces with medium to high risk of malaria transmission. Adult female mosquitoes were reared from larvae successively collected in the provinces of Nangarhar, Kunar, Badakhshan, Ghazni and Laghman from August to October 2014. WHO insecticide susceptibility tests were performed with DDT (4 %), malathion (5 %), bendiocarb (0.1 %), permethrin (0.75 %) and deltamethrin (0.05 %). In addition, the presence of kdr mutations was investigated in deltamethrin resistant and susceptible Anopheles stephensi mosquitoes collected in the eastern provinces of Nangarhar and Kunar. Analyses of mortality rates revealed emerging resistance against all four classes of insecticides in the provinces located east and south of the Hindu Kush mountain range. Resistance is observed in both An. stephensi and Anopheles culicifacies, the two dominant malaria vectors in these provinces. Anopheles superpictus in the northern province of Badakhshan shows a different pattern of susceptibility with suspected resistance observed only for deltamethrin and bendiocarb. Genotype analysis of knock down resistance (kdr) mutations at the voltage-gated channel gene from An. stephensi mosquitoes shows the presence of the known resistant alleles L1014S and L1014F. However, a significant fraction of deltamethrin-resistant mosquitoes were homozygous for the 1014L wild type allele indicating that other mechanisms must be considered to account for the observed pyrethroid resistance. This study confirms the importance of monitoring insecticide resistance for the development of an integrated vector management in Afghanistan. The

  16. Altered environment and risk of malaria outbreak in South Andaman, Andaman & Nicobar Islands, India affected by tsunami disaster

    PubMed Central

    Krishnamoorthy, Kaliannagoun; Jambulingam, Purushothaman; Natarajan, R; Shriram, AN; Das, Pradeep K; Sehgal, SC

    2005-01-01

    Background Pools of salt water and puddles created by giant waves from the sea due to the tsunami that occurred on 26th December 2004 would facilitate increased breeding of brackish water malaria vector, Anopheles sundaicus. Land uplifts in North Andaman and subsidence in South Andaman have been reported and subsidence may lead to environmental disturbances and vector proliferation. This warrants a situation analysis and vector surveillance in the tsunami hit areas endemic for malaria transmitted by brackish water mosquito, An. sundaicus to predict the risk of outbreak. Methods An extensive survey was carried out in the tsunami-affected areas in Andaman district of the Andaman and Nicobar Islands, India to assess the extent of breeding of malaria vectors in the habitats created by seawater flooding. Types of habitats in relation to source of seawater inundation and frequency were identified. The salinity of the water samples and the mosquito species present in the larval samples collected from these habitats were recorded. The malaria situation in the area was also analysed. Results South Andaman, covering Port Blair and Ferrargunj sub districts, is still under the recurring phenomenon of seawater intrusion either directly from the sea or through a network of creeks. Both daily cycles of high tides and periodical spring tides continue to cause flooding. Low-lying paddy fields and fallow land, with a salinity ranging from 3,000 to 42,505 ppm, were found to support profuse breeding of An. sundaicus, the local malaria vector, and Anopheles subpictus, a vector implicated elsewhere. This area is endemic for both vivax and falciparum malaria. Malaria slide positivity rate has started increasing during post-tsunami period, which can be considered as an indication of risk of malaria outbreak. Conclusion Paddy fields and fallow land with freshwater, hitherto not considered as potential sites for An. sundaicus, are now major breeding sites due to saline water. Consequently

  17. A risk-based methodology for ranking environmental chemical stressors at the regional scale.

    PubMed

    Giubilato, Elisa; Zabeo, Alex; Critto, Andrea; Giove, Silvio; Bierkens, Johan; Den Hond, Elly; Marcomini, Antonio

    2014-04-01

    A "Risk-based Tool for the Regional Ranking of Environmental Chemical Stressors" has been developed, aimed at supporting decision-makers in the identification of priority environmental contaminants, as well as priority areas, to be further assessed. The tool implements a methodology based on a quantitative Weight-of-Evidence approach, integrating three types of information, identified as "Lines-of-Evidence" (LoE), namely: LoE "Environmental Contamination" (including data on chemical contamination in environmental matrices in the region, thus providing information on potential population exposure), LoE "Intake" (including results from human biomonitoring studies, i.e. concentration of chemicals in human biological matrices, thus providing an integrated estimation of exposure) and LoE "Observed Effects" (including information on the incidence of adverse health outcomes associated with environmental exposure to chemicals). A Multi-Criteria Decision Analysis (MCDA) methodology based on fuzzy logic has been developed to support the integration of information related to these three LoEs for each chemical stressor. The tool allows one to rank chemical stressors at different spatial scales, such as at the regional level as well as within each sub-area (e.g., counties). Moreover, it supports the identification of priority sub-areas within the region, where environmental and health data suggest possible adverse health effects and thus more investigation efforts are needed. To evaluate the performance of this newly developed tool, a case-study in the Flemish region (north of Belgium) has been selected. In the case-study, data on soil contamination by metals and organic contaminants were integrated with data on exposure and effect biomarkers measured in adolescents within the framework of the human biomonitoring study performed by the Flemish Centre of Expertise on Environment and Health in the period 2002-2006. The case-study demonstrated the performance of the tool in

  18. Is Nigeria winning the battle against malaria? Prevalence, risk factors and KAP assessment among Hausa communities in Kano State.

    PubMed

    Dawaki, Salwa; Al-Mekhlafi, Hesham M; Ithoi, Init; Ibrahim, Jamaiah; Atroosh, Wahib M; Abdulsalam, Awatif M; Sady, Hany; Elyana, Fatin Nur; Adamu, Ado U; Yelwa, Saadatu I; Ahmed, Abdulhamid; Al-Areeqi, Mona A; Subramaniam, Lahvanya R; Nasr, Nabil A; Lau, Yee-Ling

    2016-07-08

    Malaria is one of the most severe global public health problems worldwide, particularly in Africa, where Nigeria has the greatest number of malaria cases. This community-based study was designed to investigate the prevalence and risk factors of malaria and to evaluate the knowledge, attitudes, and practices (KAP) regarding malaria among rural Hausa communities in Kano State, Nigeria. A cross-sectional community-based study was conducted on 551 participants from five local government areas in Kano State. Blood samples were collected and examined for the presence of Plasmodium species by rapid diagnostic test (RDT), Giemsa-stained thin and thick blood films, and PCR. Moreover, demographic, socioeconomic, and environmental information as well as KAP data were collected using a pre-tested questionnaire. A total of 334 (60.6 %) participants were found positive for Plasmodium falciparum. The prevalence differed significantly by age group (p < 0.01), but not by gender or location. A multivariate analysis showed that malaria was associated significantly with being aged 12 years or older, having a low household family income, not using insecticide treated nets (ITNs), and having no toilets in the house. Overall, 95.6 % of the respondents had prior knowledge about malaria, and 79.7, 87.6 and 95.7 % of them knew about the transmission, symptoms, and prevention of malaria, respectively. The majority (93.4 %) of the respondents considered malaria a serious disease. Although 79.5 % of the respondents had at least one ITN in their household, utilization rate of ITNs was 49.5 %. Significant associations between the respondents' knowledge concerning malaria and their age, gender, education, and household monthly income were reported. Malaria is still highly prevalent among rural Hausa communities in Nigeria. Despite high levels of knowledge and attitudes in the study area, significant gaps persist in appropriate preventive practices, particularly the use of ITNs

  19. Model for ranking freshwater fish farms according to their risk of infection and illustration for viral haemorrhagic septicaemia.

    PubMed

    Oidtmann, Birgit C; Pearce, Fiona M; Thrush, Mark A; Peeler, Edmund J; Ceolin, Chiara; Stärk, Katharina D C; Dalla Pozza, Manuela; Afonso, Ana; Diserens, Nicolas; Reese, R Allan; Cameron, Angus

    2014-08-01

    We developed a model to calculate a quantitative risk score for individual aquaculture sites. The score indicates the risk of the site being infected with a specific fish pathogen (viral haemorrhagic septicaemia virus (VHSV); infectious haematopoietic necrosis virus, Koi herpes virus), and is intended to be used for risk ranking sites to support surveillance for demonstration of zone or member state freedom from these pathogens. The inputs to the model include a range of quantitative and qualitative estimates of risk factors organised into five risk themes (1) Live fish and egg movements; (2) Exposure via water; (3) On-site processing; (4) Short-distance mechanical transmission; (5) Distance-independent mechanical transmission. The calculated risk score for an individual aquaculture site is a value between zero and one and is intended to indicate the risk of a site relative to the risk of other sites (thereby allowing ranking). The model was applied to evaluate 76 rainbow trout farms in 3 countries (42 from England, 32 from Italy and 2 from Switzerland) with the aim to establish their risk of being infected with VHSV. Risk scores for farms in England and Italy showed great variation, clearly enabling ranking. Scores ranged from 0.002 to 0.254 (mean score 0.080) in England and 0.011 to 0.778 (mean of 0.130) for Italy, reflecting the diversity of infection status of farms in these countries. Requirements for broader application of the model are discussed. Cost efficient farm data collection is important to realise the benefits from a risk-based approach. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  20. Malaria Risk Assessment for the Republic of Korea Based on Models of Mosquito Distribution

    DTIC Science & Technology

    2008-06-01

    unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 treatment, among a myriad of olher factors . Because the Plasmodium parasite is...Yam;lda All. kleilli Rueda All. belellme Rueda VPH 0.8 • 0.6• ~ ~ 0.’ 0.2 0 H P V VPH Figure I, Illustration of the concept of the mal-area as it...the percentage of the sampled area that these parameters cover. The value for VPH could be used as a simplified index of malaria risk to compare

  1. Adult Javanese migrants to Indonesian Papua at high risk of severe disease caused by malaria.

    PubMed

    Baird, J K; Basri, H; Weina, P; MaGuire, J D; Barcus, M J; Picarema, H; Elyazar, I R F; Ayomi, E; Sekartuti

    2003-08-01

    Migrants from Java arrive in hyperendemic Papua, Indonesia lacking exposure to endemic malaria. We evaluated records of evacuation to hospital with a diagnosis of severe malaria from a transmigration village in northeastern Papua. During the first 30 months, 198 residents with severe disease were evacuated (7.5 evacuations/100 person-years). During this period the risk of evacuation for adults (> 15 years of age) was 2.8. (95% CI = 2.1-3.8; P < 0.0001) relative to children, despite apparently equal exposure to risk of infection. Relative risk (RR) for adults was greatest during the first 6 months (RR > 16; 95% CI > or = 2.0-129; P = 0.0009), and diminished during the second 6 months (RR = 9.4; 95% CI = 2.7-32.8; P < 0.0001) and the third 6 months (RR = 3.7; 95% CI = 1.7-7.9; P = 0.0004). During the next two 6-month intervals, the RR for adults was 1.6 and 1.5 (95 % CI range 0.8-2.6; P < 0.18). Adults lacking chronic exposure were far more likely to progress to severe disease compared to children during initial exposure, but not after chronic exposure to infection.

  2. Adult Javanese migrants to Indonesian Papua at high risk of severe disease caused by malaria.

    PubMed Central

    Baird, J. K.; Basri, H.; Weina, P.; MaGuire, J. D.; Barcus, M. J.; Picarema, H.; Elyazar, I. R. F.; Ayomi, E.; Sekartuti

    2003-01-01

    Migrants from Java arrive in hyperendemic Papua, Indonesia lacking exposure to endemic malaria. We evaluated records of evacuation to hospital with a diagnosis of severe malaria from a transmigration village in northeastern Papua. During the first 30 months, 198 residents with severe disease were evacuated (7.5 evacuations/100 person-years). During this period the risk of evacuation for adults (> 15 years of age) was 2.8. (95% CI = 2.1-3.8; P < 0.0001) relative to children, despite apparently equal exposure to risk of infection. Relative risk (RR) for adults was greatest during the first 6 months (RR > 16; 95% CI > or = 2.0-129; P = 0.0009), and diminished during the second 6 months (RR = 9.4; 95% CI = 2.7-32.8; P < 0.0001) and the third 6 months (RR = 3.7; 95% CI = 1.7-7.9; P = 0.0004). During the next two 6-month intervals, the RR for adults was 1.6 and 1.5 (95 % CI range 0.8-2.6; P < 0.18). Adults lacking chronic exposure were far more likely to progress to severe disease compared to children during initial exposure, but not after chronic exposure to infection. PMID:12948380

  3. Malaria transmission risk variations derived from different agricultural practices in an irrigated area of northern Tanzania.

    PubMed

    Ijumba, J N; Mosha, F W; Lindsay, S W

    2002-03-01

    Malaria vector Anopheles and other mosquitoes (Diptera: Culicidae) were monitored for 12 months during 1994-95 in villages of Lower Moshi irrigation area (37 degrees 20' E, 3 degrees 21' S; approximately 700 m a.s.l.) south of Mount Kilimanjaro in northern Tanzania. Adult mosquito populations were sampled fortnightly by five methods: human bait collection indoors (18.00-06.00 hours) and outdoors (18.00-24.00 hours); from daytime resting-sites indoors and outdoors; by CDC light-traps over sleepers. Anopheles densities and rates of survival, anthropophily and malaria infection were compared between three villages representing different agro-ecosystems: irrigated sugarcane plantation; smallholder rice irrigation scheme, and savannah with subsistence crops. Respective study villages were Mvuleni (population 2200), Chekereni (population 3200) and Kisangasangeni (population approximately/= 1000), at least 7 km apart. Anopheles arabiensis Patton was found to be the principal malaria vector throughout the study area, with An. funestus Giles sensu lato of secondary importance in the sugarcane and savannah villages. Irrigated sugarcane cultivation resulted in water pooling, but this did not produce more vectors. Anopheles arabiensis densities averaged four-fold higher in the ricefield village, although their human blood-index was significantly less (48%) than in the sugarcane (68%) or savannah (66%) villages, despite similar proportions of humans and cows (ratio 1:1.1-1.4) as the main hosts at all sites. Parous rates, duration of the gonotrophic cycle and survival rates of An. arabiensis were similar in villages of all three agro-ecosystems. The potential risk of malaria, based on measurements of vectorial capacity of An. arabiensis and An.funestus combined, was four-fold higher in the ricefield village than in the sugarcane or savannah villages nearby. However, the more realistic estimate of malaria risk, based on entomological inoculation rates, indicated that exposure to

  4. Malaria risk behaviours, socio-cultural practices and rural livelihoods in southern Tanzania: implications for bednet usage.

    PubMed

    Dunn, Christine E; Le Mare, Ann; Makungu, Christina

    2011-02-01

    Most malaria risk reduction strategies are firmly embedded in biomedical practices and public health perspectives. National and international programmes to 'control' malaria are particularly characterised by the promotion of public health interventions which converge on the disease vector, the malaria mosquito, notably through the use of indoor household spraying with insecticides, and the deployment of insecticide-treated bednets (ITNs). With convincing evidence for the effectiveness of ITNs in reducing the incidence of malaria, control programmes have emphasised the notion of 'scaling-up' bednet coverage. Much previous research on people's 'compliance' with bednet programmes has tended to focus on the quantification of bednet usage and on deriving explanations for 'non-compliance' based on household or individual indicators such as wealth, age, gender or educational level, or on climatic factors such as season and temperature. However, malaria risk behaviours are also rooted in wider aspects of local livelihoods, and socio-cultural beliefs and practices which interplay with the use and, crucially, non-use, of bednets. This paper draws on empirical data derived from in-depth, one-to-one semi-structured interviews, focus groups and participatory methods (mapping and diagramming) with participants in two villages in rural Tanzania to explore the nature of these practices and vulnerabilities, and their potential impact on malaria exposure risk. Participants included farmers and pastoralists, both men and women, as well as village 'officials'. By eliciting local understandings of malaria-related behaviours we explore how malaria risks are played out in people's everyday lives, and the circumstances and decision-making which underpin non-usage of bednets. Our findings reveal the importance of shifting sleeping patterns in response to livelihood needs and socio-cultural practices and events. These arrangements militate against the consistent and sustained use of the

  5. Prophylaxis of Malaria

    PubMed Central

    Schwartz, Eli

    2012-01-01

    Malaria prevention in travelers to endemic areas remains dependent principally on chemoprophylaxis. Although malaria chemoprophylaxis refers to all malaria species, a distinction should be drawn between falciparum malaria prophylaxis and the prophylaxis of the relapsing malaria species (vivax & ovale). While the emergence of drug resistant strains, as well as the costs and adverse reactions to medications, complicate falciparum prophylaxis use, there are virtually no drugs available for vivax prophylaxis, beside of primaquine. Based on traveler’s malaria data, a revised recommendation for using chemoprophylaxis in low risk areas should be considered. PMID:22811794

  6. Housing Improvements and Malaria Risk in Sub-Saharan Africa: A Multi-Country Analysis of Survey Data.

    PubMed

    Tusting, Lucy S; Bottomley, Christian; Gibson, Harry; Kleinschmidt, Immo; Tatem, Andrew J; Lindsay, Steve W; Gething, Peter W

    2017-02-01

    OR 0.91, 95% CI 0.85-0.97, p = 0.003; RDT: adjusted OR 0.86, 95% CI 0.80-0.92, p < 0.001). This association was consistent regardless of ITN usage. As a comparison, the odds of malaria infection were 15% to 16% lower among ITN users versus non-users (microscopy: adjusted OR 0.84, 95% CI 0.79-0.90, p < 0.001; RDT: adjusted OR 0.85, 95% CI 0.80-0.90, p < 0.001). The main limitation of this study is that residual confounding by household wealth of the observed association between housing quality and malaria prevalence is possible, since the wealth index may not have fully captured differences in socioeconomic position; however, the use of multiple national surveys offers the advantage of a large sample size and the elimination of many biases typically associated with pooling observational data. Housing quality is an important risk factor for malaria infection across the spectrum of malaria endemicity in SSA, with a strength of association between housing quality and malaria similar to that observed between ITN use and malaria. Improved housing should be considered a promising intervention for malaria control and elimination and long-term prevention of reintroduction.

  7. Housing Improvements and Malaria Risk in Sub-Saharan Africa: A Multi-Country Analysis of Survey Data

    PubMed Central

    Bottomley, Christian; Gibson, Harry; Kleinschmidt, Immo; Tatem, Andrew J.; Gething, Peter W.

    2017-01-01

    odds of malaria infection (microscopy: adjusted OR 0.91, 95% CI 0.85–0.97, p = 0.003; RDT: adjusted OR 0.86, 95% CI 0.80–0.92, p < 0.001). This association was consistent regardless of ITN usage. As a comparison, the odds of malaria infection were 15% to 16% lower among ITN users versus non-users (microscopy: adjusted OR 0.84, 95% CI 0.79–0.90, p < 0.001; RDT: adjusted OR 0.85, 95% CI 0.80–0.90, p < 0.001). The main limitation of this study is that residual confounding by household wealth of the observed association between housing quality and malaria prevalence is possible, since the wealth index may not have fully captured differences in socioeconomic position; however, the use of multiple national surveys offers the advantage of a large sample size and the elimination of many biases typically associated with pooling observational data. Conclusions Housing quality is an important risk factor for malaria infection across the spectrum of malaria endemicity in SSA, with a strength of association between housing quality and malaria similar to that observed between ITN use and malaria. Improved housing should be considered a promising intervention for malaria control and elimination and long-term prevention of reintroduction. PMID:28222094

  8. Remote Sensing as a Landscape Epidemiologic Tool to Identify Villages at High Risk for Malaria Transmission

    NASA Technical Reports Server (NTRS)

    Beck, Louisa R.; Rodriquez, Mario H.; Dister, Sheri W.; Rodriquez, Americo D.; Rejmankova, Eliska; Ulloa, Armando; Meza, Rosa A.; Roberts, Donald R.; Paris, Jack F.; Spanner, Michael A.; Washino, Robert K.; Hacker, Carl; Legters, Llewellyn F.

    1994-01-01

    A landscape approach using remote sensing and Geographic Information System (GIS) technologies was developed to discriminate between villages at high and low risk for malaria transmission, as defined by adult Anopheles albimanus abundance. Satellite data for an area in southern Chiapas, Mexico were digitally processed to generate a map of landscape elements. The GIS processes were used to determine the proportion of mapped landscape elements surrounding 40 villages where An. albimanus data had been collected. The relationships between vector abundance and landscape element proportions were investigated using stepwise discriminant analysis and stepwise linear regression. Both analyses indicated that the most important landscape elements in terms of explaining vector abundance were transitional swamp and unmanaged pasture. Discriminant functions generated for these two elements were able to correctly distinguish between villages with high ind low vector abundance, with an overall accuracy of 90%. Regression results found both transitional swamp and unmanaged pasture proportions to be predictive of vector abundance during the mid-to-late wet season. This approach, which integrates remotely sensed data and GIS capabilities to identify villages with high vector-human contact risk, provides a promising tool for malaria surveillance programs that depend on labor-intensive field techniques. This is particularly relevant in areas where the lack of accurate surveillance capabilities may result in no malaria control action when, in fact, directed action is necessary. In general, this landscape approach could be applied to other vector-borne diseases in areas where: 1. the landscape elements critical to vector survival are known and 2. these elements can be detected at remote sensing scales.

  9. Travel history and malaria infection risk in a low-transmission setting in Ethiopia: a case control study

    PubMed Central

    2013-01-01

    Background Malaria remains the leading communicable disease in Ethiopia, with around one million clinical cases of malaria reported annually. The country currently has plans for elimination for specific geographic areas of the country. Human movement may lead to the maintenance of reservoirs of infection, complicating attempts to eliminate malaria. Methods An unmatched case–control study was conducted with 560 adult patients at a Health Centre in central Ethiopia. Patients who received a malaria test were interviewed regarding their recent travel histories. Bivariate and multivariate analyses were conducted to determine if reported travel outside of the home village within the last month was related to malaria infection status. Results After adjusting for several known confounding factors, travel away from the home village in the last 30 days was a statistically significant risk factor for infection with Plasmodium falciparum (AOR 1.76; p=0.03) but not for infection with Plasmodium vivax (AOR 1.17; p=0.62). Male sex was strongly associated with any malaria infection (AOR 2.00; p=0.001). Conclusions Given the importance of identifying reservoir infections, consideration of human movement patterns should factor into decisions regarding elimination and disease prevention, especially when targeted areas are limited to regions within a country. PMID:23347703

  10. 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.

  11. Antibodies to Plasmodium falciparum antigens predict a higher risk of malaria but protection from symptoms once parasitemic.

    PubMed

    Greenhouse, Bryan; Ho, Benjamin; Hubbard, Alan; Njama-Meya, Denise; Narum, David L; Lanar, David E; Dutta, Sheetij; Rosenthal, Philip J; Dorsey, Grant; John, Chandy C

    2011-07-01

    Associations between antibody responses to Plasmodium falciparum antigens and protection against symptomatic malaria have been difficult to ascertain, in part because antibodies are potential markers of both exposure to P. falciparum and protection against disease. We measured IgG responses to P. falciparum circumsporozoite protein, liver-stage antigen 1, apical-membrane antigen 1 (AMA-1), and merozoite surface proteins (MSP) 1 and 3, in children in Kampala, Uganda, and measured incidence of malaria before and after antibody measurement. Stronger responses to all 5 antigens were associated with an increased risk of clinical malaria (P < .01) because of confounding with prior exposure to P. falciparum. However, with use of another assessment, risk of clinical malaria once parasitemic, stronger responses to AMA-1, MSP-1, and MSP-3 were associated with protection (odds ratios, 0.34, 0.36, and 0.31, respectively, per 10-fold increase; P < .01). Analyses assessing antibodies in combination suggested that any protective effect of antibodies was overestimated by associations between individual responses and protection. Using the risk of symptomatic malaria once parasitemic as an outcome may improve detection of associations between immune responses and protection from disease. Immunoepidemiology studies designed to detect mechanisms of immune protection should integrate prior exposure into the analysis and evaluate multiple immune responses.

  12. Antibodies to Plasmodium falciparum Antigens Predict a Higher Risk of Malaria But Protection From Symptoms Once Parasitemic

    PubMed Central

    Hubbard, Alan; Njama-Meya, Denise; Narum, David L.; Lanar, David E.; Dutta, Sheetij; Rosenthal, Philip J.; Dorsey, Grant; John, Chandy C.

    2011-01-01

    (See the article by Bejon et al, on pages 9–18, and Bousema et al, on pages 1–3.) Background. Associations between antibody responses to Plasmodium falciparum antigens and protection against symptomatic malaria have been difficult to ascertain, in part because antibodies are potential markers of both exposure to P. falciparum and protection against disease. Methods. We measured IgG responses to P. falciparum circumsporozoite protein, liver-stage antigen 1, apical-membrane antigen 1 (AMA-1), and merozoite surface proteins (MSP) 1 and 3, in children in Kampala, Uganda, and measured incidence of malaria before and after antibody measurement. Results. Stronger responses to all 5 antigens were associated with an increased risk of clinical malaria (P < .01) because of confounding with prior exposure to P. falciparum. However, with use of another assessment, risk of clinical malaria once parasitemic, stronger responses to AMA-1, MSP-1, and MSP-3 were associated with protection (odds ratios, 0.34, 0.36, and 0.31, respectively, per 10-fold increase; P < .01). Analyses assessing antibodies in combination suggested that any protective effect of antibodies was overestimated by associations between individual responses and protection. Conclusions. Using the risk of symptomatic malaria once parasitemic as an outcome may improve detection of associations between immune responses and protection from disease. Immunoepidemiology studies designed to detect mechanisms of immune protection should integrate prior exposure into the analysis and evaluate multiple immune responses. PMID:21628654

  13. Mapping malaria risk among children in Côte d'Ivoire using Bayesian geo-statistical models.

    PubMed

    Raso, Giovanna; Schur, Nadine; Utzinger, Jürg; Koudou, Benjamin G; Tchicaya, Emile S; Rohner, Fabian; N'goran, Eliézer K; Silué, Kigbafori D; Matthys, Barbara; Assi, Serge; Tanner, Marcel; Vounatsou, Penelope

    2012-05-09

    In Côte d'Ivoire, an estimated 767,000 disability-adjusted life years are due to malaria, placing the country at position number 14 with regard to the global burden of malaria. Risk maps are important to guide control interventions, and hence, the aim of this study was to predict the geographical distribution of malaria infection risk in children aged <16 years in Côte d'Ivoire at high spatial resolution. Using different data sources, a systematic review was carried out to compile and geo-reference survey data on Plasmodium spp. infection prevalence in Côte d'Ivoire, focusing on children aged <16 years. The period from 1988 to 2007 was covered. A suite of Bayesian geo-statistical logistic regression models was fitted to analyse malaria risk. Non-spatial models with and without exchangeable random effect parameters were compared to stationary and non-stationary spatial models. Non-stationarity was modelled assuming that the underlying spatial process is a mixture of separate stationary processes in each ecological zone. The best fitting model based on the deviance information criterion was used to predict Plasmodium spp. infection risk for entire Côte d'Ivoire, including uncertainty. Overall, 235 data points at 170 unique survey locations with malaria prevalence data for individuals aged <16 years were extracted. Most data points (n = 182, 77.4%) were collected between 2000 and 2007. A Bayesian non-stationary regression model showed the best fit with annualized rainfall and maximum land surface temperature identified as significant environmental covariates. This model was used to predict malaria infection risk at non-sampled locations. High-risk areas were mainly found in the north-central and western area, while relatively low-risk areas were located in the north at the country border, in the north-east, in the south-east around Abidjan, and in the central-west between two high prevalence areas. The malaria risk map at high spatial resolution gives an

  14. Using Respondent Driven Sampling to Identify Malaria Risks and Occupational Networks among Migrant Workers in Ranong, Thailand

    PubMed Central

    Wangroongsarb, Piyaporn; Hwang, Jimee; Thwing, Julie; Karuchit, Samart; Kumpetch, Suthon; Rand, Alison; Drakeley, Chris; MacArthur, John R.; Kachur, S. Patrick; Satimai, Wichai; Meek, Sylvia; Sintasath, David M.

    2016-01-01

    Background Ranong Province in southern Thailand is one of the primary entry points for migrants entering Thailand from Myanmar, and borders Kawthaung Township in Myanmar where artemisinin resistance in malaria parasites has been detected. Areas of high population movement could increase the risk of spread of artemisinin resistance in this region and beyond. Methods A respondent-driven sampling (RDS) methodology was used to compare migrant populations coming from Myanmar in urban (Site 1) vs. rural (Site 2) settings in Ranong, Thailand. The RDS methodology collected information on knowledge, attitudes, and practices for malaria, travel and occupational histories, as well as social network size and structure. Individuals enrolled were screened for malaria by microscopy, Real Time-PCR, and serology. Results A total of 619 participants were recruited in Ranong City and 623 participants in Kraburi, a rural sub-district. By PCR, a total of 14 (1.1%) samples were positive (2 P. falciparum in Site 1; 10 P. vivax, 1 Pf, and 1 P. malariae in Site 2). PCR analysis demonstrated an overall weighted prevalence of 0.5% (95% CI, 0–1.3%) in the urban site and 1.0% (95% CI, 0.5–1.7%) in the rural site for all parasite species. PCR positivity did not correlate with serological positivity; however, as expected there was a strong association between antibody prevalence and both age and exposure. Access to long-lasting insecticidal treated nets remains low despite relatively high reported traditional net use among these populations. Conclusions The low malaria prevalence, relatively smaller networks among migrants in rural settings, and limited frequency of travel to and from other areas of malaria transmission in Myanmar, suggest that the risk for the spread of artemisinin resistance from this area may be limited in these networks currently but may have implications for regional malaria elimination efforts. PMID:28033322

  15. Population Movement as a Risk Factor for Malaria Infection in High-Altitude Villages of Tahtay-Maychew District, Tigray, Northern Ethiopia: A Case-Ccontrol Study.

    PubMed

    Haile, Mebrahtom; Lemma, Hailemariam; Weldu, Yemane

    2017-06-19

    Key goal and targets of the Ethiopian national malaria control strategy are to achieve malaria elimination within specific geographical areas with historically low malaria transmission and to reach near-zero malaria transmission in the remaining malarious areas by 2020. However, back and forth population movement between high-transmission and low-transmission area imposes challenge on the success of national malaria control programs. Therefore, examining the effect of human movement and identification of at-risk populations is crucial in an elimination setting. A matched case-control study was conducted among 520 study participants at a community level in low malaria transmission settings in northern Ethiopia. Study participants who received a malaria test were interviewed regarding their recent travel history. Bivariate and multivariate analyses were carried out to determine if the reported travel was related to malaria infection. Younger age (adjusted odds ratio [AOR] = 3.20, 95% confidence interval [CI]: 1.73, 5.89) and travel in the previous month (AOR = 11.40, 95% CI: 6.91, 18.82) were statistically significant risk factors for malaria infection. Other statistically significant factors, including lower educational level (AOR = 2.21, 95% CI: 1.26, 3.86) and nonagricultural in occupation (AOR = 2.0, 95% CI: 1.02, 3.94), were also found as risk factors for malaria infection. Generally, travel history was found to be a strong predictor for malaria acquisition in the high-altitude villages. Therefore, besides the existing efforts in endemic areas, targeting those who frequently travel to malarious areas is crucial to reduce malaria infection risks and possibility of local transmissions in high-altitude areas of northern Ethiopia.

  16. [Assessment of malaria resurgence risk in Morocco. Study of the vectorial capacity of Anopheles labranchiae in a rice cultivation area in the north of the country].

    PubMed

    Faraj, C; Ouahabi, S; Adlaoui, E; Boccolini, D; Romi, R; El Aouad, R

    2008-12-01

    To assess the malaria reintroduction risk in Morocco, we analyzed the malariogenic potential of a rice cultivation area in the north of the country. Our results showed that the receptivity of this area is very high during all the period of the rice cultivation, from May to October, the vectorial capacity of An. labranchiae, malaria vector in Morocco, is considerably high during the summer which corresponds to the rice cultivation period. The risk of autochthonous malaria resumption is important because of the possible presence of gametocytes carriers in the last malaria focus which is bordering the study area. The risk of a tropical malaria introduction is unimportant seen the low vulnerability of the area and the uncertain competence of its vectors considered. However, this risk must be considered with a more attention.

  17. Risk Assessment of Malaria Prevalence in Ludian, Yongshan, and Jinggu Counties, Yunnan Province, after 2014 Earthquake Disaster

    PubMed Central

    Feng, Jun; Xia, Zhigui; Zhang, Li; Cheng, Siyuan; Wang, Rubo

    2016-01-01

    The objective of this study was to investigate malaria prevalence after the 2014 earthquakes in Ludian, Yongshan, and Jinggu counties, Yunnan Province, China. We collected and analyzed epidemiological data and made a risk assessment of transmission probability. From January 2005 to July 2015, 87 malaria cases were reported in the three counties, most of which (81.6%) occurred between 2005 and 2009, with five cases reported in Jinggu County between January 2014 and July 2015, of which one case was reported after the earthquake. In addition, no local transmission occurred in the three counties from 2010, and 95.5% of imported malaria occurred in patients who had returned from Myanmar. The townships of Lehong, Qingsheng, and Weiyuan were the main endemic areas in the three counties. The probability of malaria transmission in the three counties was low, but Jinggu County had a higher risk due to the existence of infected patients and an appropriate vector. With sporadic cases reported annually, close monitoring should continue to enhance early detection of a possible malaria outbreak. PMID:26711514

  18. Risk Assessment of Malaria Prevalence in Ludian, Yongshan, and Jinggu Counties, Yunnan Province, After 2014 Earthquake Disaster.

    PubMed

    Feng, Jun; Xia, Zhigui; Zhang, Li; Cheng, Siyuan; Wang, Rubo

    2016-03-01

    The objective of this study was to investigate malaria prevalence after the 2014 earthquakes in Ludian, Yongshan, and Jinggu counties, Yunnan Province, China. We collected and analyzed epidemiological data and made a risk assessment of transmission probability. From January 2005 to July 2015, 87 malaria cases were reported in the three counties, most of which (81.6%) occurred between 2005 and 2009, with five cases reported in Jinggu County between January 2014 and July 2015, of which one case was reported after the earthquake. In addition, no local transmission occurred in the three counties from 2010, and 95.5% of imported malaria occurred in patients who had returned from Myanmar. The townships of Lehong, Qingsheng, and Weiyuan were the main endemic areas in the three counties. The probability of malaria transmission in the three counties was low, but Jinggu County had a higher risk due to the existence of infected patients and an appropriate vector. With sporadic cases reported annually, close monitoring should continue to enhance early detection of a possible malaria outbreak. © The American Society of Tropical Medicine and Hygiene.

  19. Estimating personalized risk ranking using laboratory test and medical knowledge (UMLS).

    PubMed

    Patil, Meru A; Bhaumik, Sandip; Paul, Soubhik; Bissoyi, Swarupananda; Roy, Raj; Ryu, Seungwoo

    2013-01-01

    In this paper, we introduce a Concept Graph Engine (CG-Engine) that generates patient specific personalized disease ranking based on the laboratory test data. CG-Engine uses the Unified Medical Language System database as medical knowledge base. The CG-Engine consists of two concepts namely, a concept graph and its attributes. The concept graph is a two level tree that starts at a laboratory test root node and ends at a disease node. The attributes of concept graph are: Relation types, Semantic types, Number of Sources and Symmetric Information between nodes. These attributes are used to compute the weight between laboratory tests and diseases. The personalized disease ranking is created by aggregating the weights of all the paths connecting between a particular disease and contributing abnormal laboratory tests. The clinical application of CG-Engine improves physician's throughput as it provides the snapshot view of abnormal laboratory tests as well as a personalized disease ranking.

  20. Nutritional and socio-demographic risk indicators of malaria in children under five: a cross-sectional study in a Sudanese rural community.

    PubMed

    el Samani, F Z; Willett, W C; Ware, J H

    1987-04-01

    This paper reports the results of a cross-sectional study of the association between nutritional, environmental and socio-demographic factors, and malaria occurrence among 445 children under 5 years of age in a Sudanese rural community. The overall frequency of malaria as defined by a history of clinical illness during the previous 2 months was 27%. Malaria occurrence was positively associated with the degree of malnutrition as assessed by weight-for-age. The age-adjusted odds ratio for mild malnutrition and history of malaria was 1.2 (95% confidence interval (CI): 0.7-2.0) and for moderate malnutrition and malaria was 2.1 (95% CI: 1.1-4.0). Malaria was less frequent among children 0-11 months of age relative to older children (OR = 0.4; 95% CI:0.2-0.7), and was inversely associated with ownership of a refrigerator (OR = 0.5; 95% CI:0.36-0.94), an indicator of socio-economic status. Indicators of crowding were the best predictors of the risk of malaria. Less malaria was observed in households with three or more rooms (OR = 0.6; 95% CI:0.37-0.98) and more malaria was observed in households with more than five people (OR = 2.5; 95% CI:1.4-4.5). Malaria was slightly, but not significantly, more frequent among boys and was associated with anaemia, which was probably an outcome of malaria in the past. These data suggest that undernutrition may increase the risk of malaria, and draw attention to the importance of socio-economic and environmental factors in relation to this disease. These relationships deserve further examination in prospective follow-up studies that are better able to evaluate the temporal relations of malnutrition and malaria.

  1. Development of a risk-ranking framework to evaluate potential high-threat microorganisms, toxins, and chemicals in food.

    PubMed

    Newsome, R; Tran, N; Paoli, G M; Jaykus, L A; Tompkin, B; Miliotis, M; Ruthman, T; Hartnett, E; Busta, F F; Petersen, B; Shank, F; McEntire, J; Hotchkiss, J; Wagner, M; Schaffner, D W

    2009-03-01

    Through a cooperative agreement with the U.S. Food and Drug Administration, the Institute of Food Technologists developed a risk-ranking framework prototype to enable comparison of microbiological and chemical hazards in foods and to assist policy makers, risk managers, risk analysts, and others in determining the relative public health impact of specific hazard-food combinations. The prototype is a bottom-up system based on assumptions that incorporate expert opinion/insight with a number of exposure and hazard-related risk criteria variables, which are propagated forward with food intake data to produce risk-ranking determinations. The prototype produces a semi-quantitative comparative assessment of food safety hazards and the impacts of hazard control measures. For a specific hazard-food combination the prototype can produce a single metric: a final risk value expressed as annual pseudo-disability adjusted life years (pDALY). The pDALY is a harmonization of the very different dose-response relationships observed for chemicals and microbes. The prototype was developed on 2 platforms, a web-based user interface and an Analytica(R) model (Lumina Decision Systems, Los Gatos, Calif., U.S.A.). Comprising visual basic language, the web-based platform facilitates data input and allows use concurrently from multiple locations. The Analytica model facilitates visualization of the logic flow, interrelationship of input and output variables, and calculations/algorithms comprising the prototype. A variety of sortable risk-ranking reports and summary information can be generated for hazard-food pairs, showing hazard and dose-response assumptions and data, per capita consumption by population group, and annual p-DALY.

  2. A quantitative risk assessment approach for mosquito-borne diseases: malaria re-emergence in southern France

    PubMed Central

    Ponçon, Nicolas; Tran, Annelise; Toty, Céline; Luty, Adrian JF; Fontenille, Didier

    2008-01-01

    Background The Camargue region is a former malaria endemic area, where potential Anopheles vectors are still abundant. Considering the importation of Plasmodium due to the high number of imported malaria cases in France, the aim of this article was to make some predictions regarding the risk of malaria re-emergence in the Camargue. Methods Receptivity (vectorial capacity) and infectivity (vector susceptibility) were inferred using an innovative probabilistic approach and considering both Plasmodium falciparum and Plasmodium vivax. Each parameter of receptivity (human biting rate, anthropophily, length of trophogonic cycle, survival rate, length of sporogonic cycle) and infectivity were estimated based on field survey, bibliographic data and expert knowledge and fitted with probability distributions taking into account the variability and the uncertainty of the estimation. Spatial and temporal variations of the parameters were determined using environmental factors derived from satellite imagery, meteorological data and entomological field data. The entomological risk (receptivity/infectivity) was calculated using 10,000 different randomly selected sets of values extracted from the probability distributions. The result was mapped in the Camargue area. Finally, vulnerability (number of malaria imported cases) was inferred using data collected in regional hospitals. Results The entomological risk presented large spatial, temporal and Plasmodium species-dependent variations. The sensitivity analysis showed that susceptibility, survival rate and human biting rate were the three most influential parameters for entomological risk. Assessment of vulnerability showed that among the imported cases in the region, only very few were imported in at-risk areas. Conclusion The current risk of malaria re-emergence seems negligible due to the very low number of imported Plasmodium. This model demonstrated its efficiency for mosquito-borne diseases risk assessment. PMID:18673551

  3. Urban and architectural risk factors for malaria in indigenous Amazonian settlements in Brazil: a typological analysis.

    PubMed

    Leandro-Reguillo, Patricia; Thomson-Luque, Richard; Monteiro, Wuelton M; de Lacerda, Marcus V G

    2015-07-22

    In the Amazon, m alaria is highly endemic in indigenous populations, which are often considered one of the last barriers to malaria elimination due to geographic isolation. Although the improvement of housing conditions is a good strategy towards the control and prevention of vector-borne diseases, such as malaria, this preventive practice has been barely undertaken in Latin America. An analysis of the architectural and urban features of indigenous Amazonian populations is essential to define and adapt these vector control measures. A total of 32 villages of 29 different ethnicities were studied and mapped by reviewing literature and visual information, and using a geographic information system. The most important architectural and urban characteristics influencing malaria were analysed according to the following categories: number of households and dimensions, supporting area, openings, materials, lifespan and location. Housing typologies found were classified within each of these variables. The results of this typological analysis included an easy-to-handle working template and revealing of features that benefit or hamper the presence of malaria vectors in Amerindians communities. Among risk factors, presence of open eaves, permeable walls, open-side constructions, large number of sleepers indoors, temporary-ephemeral houses, linear villages along stream banks, houseboats villages, poor urban drainage and villages surrounded by anthropogenic environments were highlighted. Indigenous settlements very permissive for anophelines were identified in ethnic groups, such as the Yanomami, Palikur, Paumari, Waimiri-Atroari and Wajãpi. Positive features were also recognized, including opaque and closed houses, large radial villages on bare soil, highly elevated stilted houses and the fire indoors, found among the Yawalapiti, Ashaninka, and Gavião-Parkatejê tribes. However, as Amazonian indigenous settlement typologies vary greatly even among villages of the same ethnic

  4. Malaria Prevention, Mefloquine Neurotoxicity, Neuropsychiatric Illness, and Risk-Benefit Analysis in the Australian Defence Force

    PubMed Central

    McCarthy, Stuart

    2015-01-01

    The Australian Defence Force (ADF) has used mefloquine for malaria chemoprophylaxis since 1990. Mefloquine has been found to be a plausible cause of a chronic central nervous system toxicity syndrome and a confounding factor in the diagnosis of existing neuropsychiatric illnesses prevalent in the ADF such as posttraumatic stress disorder and traumatic brain injury. Overall health risks appear to have been mitigated by restricting the drug's use; however serious risks were realised when significant numbers of ADF personnel were subjected to clinical trials involving the drug. The full extent of the exposure, health impacts for affected individuals, and consequences for ADF health management including mental health are not yet known, but mefloquine may have caused or aggravated neuropsychiatric illness in large numbers of patients who were subsequently misdiagnosed and mistreated or otherwise failed to receive proper care. Findings in relation to chronic mefloquine neurotoxicity were foreseeable, but this eventuality appears not to have been considered during risk-benefit analyses. Thorough analysis by the ADF would have identified this long-term risk as well as other qualitative risk factors. Historical exposure of ADF personnel to mefloquine neurotoxicity now also necessitates ongoing risk monitoring and management in the overall context of broader health policies. PMID:26793391

  5. Application of Risk Analysis Based On Remote Sensing and Geographic Information System Technologies To Control of Malaria In Nigeria

    NASA Astrophysics Data System (ADS)

    Njemanze, Philip; Njemanze, Philip; Peters, Constance; Uwaeziozi, Amarachukwu

    More than 1 million Africans die from malaria each year. Remote sensing (RS) and geographic information system (GIS) technologies could be applied to study the risk of malaria epidemic. The patient population included 45,140 of persons aged 0-85 years seen at primary health centers in 18 different local government areas (LGAs) of Imo State. Maps of old Imo State were converted to digital form using ARC/INFO GIS software, and the resulting coverages included hydrology, towns, and villages. Remote sensing images from Advanced Very High Resolution Radiometer (AVHRR) data set were used to obtain color-coded monthly normalized-difference vegetation index or NDVI. Three groups were distinguished as: group A LGAs using water from natural hydrology and bore-holes, group B - using rain water harvesting from roof tops into surface water reservoirs, and group C - using ground surface catchment of rain water with ground ponds. These stagnant ponds were Anopheles mosquito breeding sites. The NDVI values were used to determine water availability, and were least in January/February each year, and highest in April/May. Probabilistic layer analysis (PLA) was used to determine the Odds Ratio (OR), Relative Risk (RR) and Attributable Risk (AR) for malaria in groups A, B, C. Significant risk for malaria was associated with local water conservation methods in group C, compared to A, (OR = 4.55; RR = 4.46, AR = 77.6

  6. Dynamics of Socioeconomic Risk Factors for Neglected Tropical Diseases and Malaria in an Armed Conflict

    PubMed Central

    Fürst, Thomas; Raso, Giovanna; Acka, Cinthia A.; Tschannen, Andres B.; N'Goran, Eliézer K.; Utzinger, Jürg

    2009-01-01

    Background Armed conflict and war are among the leading causes of disability and premature death, and there is a growing share of civilians killed or injured during armed conflicts. A major part of the civilian suffering stems from indirect effects or collateral impact such as changing risk profiles for infectious diseases. We focused on rural communities in the western part of Côte d'Ivoire, where fighting took place during the Ivorian civil war in 2002/2003, and assessed the dynamics of socioeconomic risk factors for neglected tropical diseases (NTDs) and malaria. Methodology The same standardized and pre-tested questionnaires were administered to the heads of 182 randomly selected households in 25 villages in the region of Man, western Côte d'Ivoire, shortly before and after the 2002/2003 armed conflict. Principal Findings There was no difference in crowding as measured by the number of individuals per sleeping room, but the inadequate sanitation infrastructure prior to the conflict further worsened, and the availability and use of protective measures against mosquito bites and accessibility to health care infrastructure deteriorated. Although the direct causal chain between these findings and the conflict are incomplete, partially explained by the very nature of working in conflict areas, the timing and procedures of the survey, other sources and anecdotal evidence point toward a relationship between an increased risk of suffering from NTDs and malaria and armed conflict. Conclusion New research is needed to deepen our understanding of the often diffuse and neglected indirect effects of armed conflict and war, which may be worse than the more obvious, direct effects. PMID:19907632

  7. Dynamics of socioeconomic risk factors for neglected tropical diseases and malaria in an armed conflict.

    PubMed

    Fürst, Thomas; Raso, Giovanna; Acka, Cinthia A; Tschannen, Andres B; N'Goran, Eliézer K; Utzinger, Jürg

    2009-09-08

    Armed conflict and war are among the leading causes of disability and premature death, and there is a growing share of civilians killed or injured during armed conflicts. A major part of the civilian suffering stems from indirect effects or collateral impact such as changing risk profiles for infectious diseases. We focused on rural communities in the western part of Côte d'Ivoire, where fighting took place during the Ivorian civil war in 2002/2003, and assessed the dynamics of socioeconomic risk factors for neglected tropical diseases (NTDs) and malaria. The same standardized and pre-tested questionnaires were administered to the heads of 182 randomly selected households in 25 villages in the region of Man, western Côte d'Ivoire, shortly before and after the 2002/2003 armed conflict. There was no difference in crowding as measured by the number of individuals per sleeping room, but the inadequate sanitation infrastructure prior to the conflict further worsened, and the availability and use of protective measures against mosquito bites and accessibility to health care infrastructure deteriorated. Although the direct causal chain between these findings and the conflict are incomplete, partially explained by the very nature of working in conflict areas, the timing and procedures of the survey, other sources and anecdotal evidence point toward a relationship between an increased risk of suffering from NTDs and malaria and armed conflict. New research is needed to deepen our understanding of the often diffuse and neglected indirect effects of armed conflict and war, which may be worse than the more obvious, direct effects.

  8. [Risk factors for death from severe malaria in children at the Charles de Gaulle pediatric hospital of Ouagadougou (Burkina Faso)].

    PubMed

    Kouéta, Fla; Dao, Lassina; Yé, Diarra; Zoungrana, Alice; Kaboré, Aïssata; Sawadogo, Alphonse

    2007-01-01

    To determine the risk factors for death from severe malaria in children in Burkina Faso, we conducted a retrospective case-control study covering a period of 24 months from January 2004 through December 2005, at the Charles de Gaulle Pediatric Hospital in Ouagadougou. Cases (n=72) were defined as all children hospitalized for and dying of confirmed severe malaria. The control subjects (n=72), matched for age, sex and date of hospitalization; were children hospitalized for confirmed severe malaria who were discharged after recovery. Risk factors assessed included: place of residence, socioeconomic level, self-medication, promptness of hospitalization, nutritional status, temperature and parasitemia. Case and control children were compared with pairwise tests. Low socioeconomic level (OR=5.4), late care (OR=15.5), poor nutritional status (OR=7.9) and a parasitemia greater than or equal to 5% (OR=2.8) were associated with a significant increase in the risk of death. In contrast, the malaria deaths were not associated with place of residence (OR=0.5), self-medication (OR=1) or fever of 41 degrees C or higher (OR=1.1). These results show the need for more health education to encourage early care-seeking in the event of fever, community-based interventions, and strengthening of the technical support centers for health facilities, as part of a national poverty reduction program.

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

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  11. A simplified risk-ranking system for prioritizing toxic pollution sites in low- and middle-income countries.

    PubMed

    Caravanos, Jack; Gualtero, Sandra; Dowling, Russell; Ericson, Bret; Keith, John; Hanrahan, David; Fuller, Richard

    2014-01-01

    In low- and middle-income countries (LMICs), chemical exposures in the environment due to hazardous waste sites and toxic pollutants are typically poorly documented and their health impacts insufficiently quantified. Furthermore, there often is only limited understanding of the health and environmental consequences of point source pollution problems, and little consensus on how to assess and rank them. The contributions of toxic environmental exposures to the global burden of disease are not well characterized. The aim of this study was to describe the simple but effective approach taken by Blacksmith Institute's Toxic Sites Identification Program to quantify and rank toxic exposures in LMICs. This system is already in use at more than 3000 sites in 48 countries such as India, Indonesia, China, Ghana, Kenya, Tanzania, Peru, Bolivia, Argentina, Uruguay, Armenia, Azerbaijan, and Ukraine. A hazard ranking system formula, the Blacksmith Index (BI), takes into account important factors such as the scale of the pollution source, the size of the population possibly affected, and the exposure pathways, and is designed for use reliably in low-resource settings by local personnel provided with limited training. Four representative case studies are presented, with varying locations, populations, pollutants, and exposure pathways. The BI was successfully applied to assess the extent and severity of environmental pollution problems at these sites. The BI is a risk-ranking tool that provides direct and straightforward characterization, quantification, and prioritization of toxic pollution sites in settings where time, money, or resources are limited. It will be an important and useful tool for addressing toxic pollution problems in LMICs. Although the BI does not have the sophistication of the US Environmental Protection Agency's Hazard Ranking System, the case studies presented here document the effectiveness of the BI in the field, especially in low-resource settings

  12. Plasmodium falciparum multiple infections in Mozambique, its relation to other malariological indices and to prospective risk of malaria morbidity.

    PubMed

    Mayor, Alfredo; Saute, Francisco; Aponte, John J; Almeda, Jesús; Gómez-Olivé, F Xavier; Dgedge, Martinho; Alonso, Pedro L

    2003-01-01

    We describe the frequency of Plasmodium falciparum clones infecting individuals living in a rural area of southern Mozambique and analyse the relationship between multiplicity of infection, age and other malariometric indices, including prospective risk of clinical malaria. The genotyping was based on the use of restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) analysis of P. falciparum merozoite surface protein 2 (msp2). We analysed 826 samples collected during five cross-sectional surveys from residents of Manhiça ranging in age from 4 months to 83 years. We also determined the multiplicity of infection in samples obtained from 6-month-old infants (n = 79) and children <10 years (n = 158) who were then treated and followed prospectively for 1 year or 75 weeks, respectively. Multiplicity of infection did not vary significantly during the first year of life, but increased thereafter, and decreased during adulthood to the levels found in infants. With increasing multiplicity of infection, there was a statistically significant decrease in the risk of submicroscopic infections. There was also a significant correlation between multiplicity of infection and parasite density in infants, children <4 years of age and adults, suggesting that high densities increase the probability of discriminating more clones in complex infections. We found that the relationship between multiple infections and malaria morbidity is age-dependent. In infants, the risk of subsequent episodes of clinical malaria was related to the parasite density but not to baseline multiplicity of infection. In older children, however, the more clones a child carried, the more likely they were to have a clinical malaria episode, and this was true after adjusting for parasite densities. This change in the association between multiplicity and risk of clinical malaria may indicate a shift in the host response to P. falciparum.

  13. Sickle Cell Trait and the Risk of Plasmodium falciparum Malaria and Other Childhood Diseases

    PubMed Central

    Williams, Thomas N.; Mwangi, Tabitha W.; Wambua, Sammy; Alexander, Neal D.; Kortok, Moses; Snow, Robert W.; Marsh, Kevin

    2012-01-01

    Background The gene for sickle hemoglobin (HbS) is a prime example of natural selection. It is generally believed that its current prevalence in many tropical populations reflects selection for the carrier form (sickle cell trait [HbAS]) through a survival advantage against death from malaria. Nevertheless, >50 years after this hypothesis was first proposed, the epidemiological description of the relationships between HbAS, malaria, and other common causes of child mortality remains incomplete. Methods We studied the incidence of falciparum malaria and other childhood diseases in 2 cohorts of children living on the coast of Kenya. Results The protective effect of HbAS was remarkably specific for falciparum malaria, having no significant impact on any other disease. HbAS had no effect on the prevalence of symptomless parasitemia but was 50% protective against mild clinical malaria, 75% protective against admission to the hospital for malaria, and almost 90% protective against severe or complicated malaria. The effect of HbAS on episodes of clinical malaria was mirrored in its effect on parasite densities during such episodes. Conclusions The present data are useful in that they confirm the mechanisms by which HbAS confers protection against malaria and shed light on the relationships between HbAS, malaria, and other childhood diseases. PMID:15942909

  14. The impact of regional climate change on malaria risk due to greenhouse forcing and land-use changes in tropical Africa.

    PubMed

    Ermert, Volker; Fink, Andreas H; Morse, Andrew P; Paeth, Heiko

    2012-01-01

    Climate change will probably alter the spread and transmission intensity of malaria in Africa. In this study, we assessed potential changes in the malaria transmission via an integrated weather-disease model. We simulated mosquito biting rates using the Liverpool Malaria Model (LMM). The input data for the LMM were bias-corrected temperature and precipitation data from the regional model (REMO) on a 0.5° latitude-longitude grid. A Plasmodium falciparum infection model expands the LMM simulations to incorporate information on the infection rate among children. Malaria projections were carried out with this integrated weather-disease model for 2001 to 2050 according to two climate scenarios that include the effect of anthropogenic land-use and land-cover changes on climate. Model-based estimates for the present climate (1960 to 2000) are consistent with observed data for the spread of malaria in Africa. In the model domain, the regions where malaria is epidemic are located in the Sahel as well as in various highland territories. A decreased spread of malaria over most parts of tropical Africa is projected because of simulated increased surface temperatures and a significant reduction in annual rainfall. However, the likelihood of malaria epidemics is projected to increase in the southern part of the Sahel. In most of East Africa, the intensity of malaria transmission is expected to increase. Projections indicate that highland areas that were formerly unsuitable for malaria will become epidemic, whereas in the lower-altitude regions of the East African highlands, epidemic risk will decrease. We project that climate changes driven by greenhouse-gas and land-use changes will significantly affect the spread of malaria in tropical Africa well before 2050. The geographic distribution of areas where malaria is epidemic might have to be significantly altered in the coming decades.

  15. The Impact of Regional Climate Change on Malaria Risk due to Greenhouse Forcing and Land-Use Changes in Tropical Africa

    PubMed Central

    Fink, Andreas H.; Morse, Andrew P.; Paeth, Heiko

    2011-01-01

    Background: Climate change will probably alter the spread and transmission intensity of malaria in Africa. Objectives: In this study, we assessed potential changes in the malaria transmission via an integrated weather–disease model. Methods: We simulated mosquito biting rates using the Liverpool Malaria Model (LMM). The input data for the LMM were bias-corrected temperature and precipitation data from the regional model (REMO) on a 0.5° latitude–longitude grid. A Plasmodium falciparum infection model expands the LMM simulations to incorporate information on the infection rate among children. Malaria projections were carried out with this integrated weather–disease model for 2001 to 2050 according to two climate scenarios that include the effect of anthropogenic land-use and land-cover changes on climate. Results: Model-based estimates for the present climate (1960 to 2000) are consistent with observed data for the spread of malaria in Africa. In the model domain, the regions where malaria is epidemic are located in the Sahel as well as in various highland territories. A decreased spread of malaria over most parts of tropical Africa is projected because of simulated increased surface temperatures and a significant reduction in annual rainfall. However, the likelihood of malaria epidemics is projected to increase in the southern part of the Sahel. In most of East Africa, the intensity of malaria transmission is expected to increase. Projections indicate that highland areas that were formerly unsuitable for malaria will become epidemic, whereas in the lower-altitude regions of the East African highlands, epidemic risk will decrease. Conclusions: We project that climate changes driven by greenhouse-gas and land-use changes will significantly affect the spread of malaria in tropical Africa well before 2050. The geographic distribution of areas where malaria is epidemic might have to be significantly altered in the coming decades. PMID:21900078

  16. Surveillance and response for high-risk populations: what can malaria elimination programmes learn from the experience of HIV?

    PubMed

    Jacobson, Jerry O; Cueto, Carmen; Smith, Jennifer L; Hwang, Jimee; Gosling, Roly; Bennett, Adam

    2017-01-18

    To eliminate malaria, malaria programmes need to develop new strategies for surveillance and response appropriate for the changing epidemiology that accompanies transmission decline, in which transmission is increasingly driven by population subgroups whose behaviours place them at increased exposure. Conventional tools of malaria surveillance and response are likely not sufficient in many elimination settings for accessing high-risk population subgroups, such as mobile and migrant populations (MMPs), given their greater likelihood of asymptomatic infections, illegal risk behaviours, limited access to public health facilities, and high mobility including extended periods travelling away from home. More adaptive, targeted strategies are needed to monitor transmission and intervention coverage effectively in these groups. Much can be learned from HIV programmes' experience with "second generation surveillance", including how to rapidly adapt surveillance and response strategies to changing transmission patterns, biological and behavioural surveys that utilize targeted sampling methods for specific behavioural subgroups, and methods for population size estimation. This paper reviews the strategies employed effectively for HIV programmes and offers considerations and recommendations for adapting them to the malaria elimination context.

  17. Use of mechanistic simulations as a quantitative risk-ranking tool within the quality by design framework.

    PubMed

    Stocker, Elena; Toschkoff, Gregor; Sacher, Stephan; Khinast, Johannes G

    2014-11-20

    The purpose of this study is to evaluate the use of computer simulations for generating quantitative knowledge as a basis for risk ranking and mechanistic process understanding, as required by ICH Q9 on quality risk management systems. In this specific publication, the main focus is the demonstration of a risk assessment workflow, including a computer simulation for the generation of mechanistic understanding of active tablet coating in a pan coater. Process parameter screening studies are statistically planned under consideration of impacts on a potentially critical quality attribute, i.e., coating mass uniformity. Based on computer simulation data the process failure mode and effects analysis of the risk factors is performed. This results in a quantitative criticality assessment of process parameters and the risk priority evaluation of failure modes. The factor for a quantitative reassessment of the criticality and risk priority is the coefficient of variation, which represents the coating mass uniformity. The major conclusion drawn from this work is a successful demonstration of the integration of computer simulation in the risk management workflow leading to an objective and quantitative risk assessment.

  18. FDA-iRISK--a comparative risk assessment system for evaluating and ranking food-hazard pairs: case studies on microbial hazards.

    PubMed

    Chen, Yuhuan; Dennis, Sherri B; Hartnett, Emma; Paoli, Greg; Pouillot, Régis; Ruthman, Todd; Wilson, Margaret

    2013-03-01

    Stakeholders in the system of food safety, in particular federal agencies, need evidence-based, transparent, and rigorous approaches to estimate and compare the risk of foodborne illness from microbial and chemical hazards and the public health impact of interventions. FDA-iRISK (referred to here as iRISK), a Web-based quantitative risk assessment system, was developed to meet this need. The modeling tool enables users to assess, compare, and rank the risks posed by multiple food-hazard pairs at all stages of the food supply system, from primary production, through manufacturing and processing, to retail distribution and, ultimately, to the consumer. Using standard data entry templates, built-in mathematical functions, and Monte Carlo simulation techniques, iRISK integrates data and assumptions from seven components: the food, the hazard, the population of consumers, process models describing the introduction and fate of the hazard up to the point of consumption, consumption patterns, dose-response curves, and health effects. Beyond risk ranking, iRISK enables users to estimate and compare the impact of interventions and control measures on public health risk. iRISK provides estimates of the impact of proposed interventions in various ways, including changes in the mean risk of illness and burden of disease metrics, such as losses in disability-adjusted life years. Case studies for Listeria monocytogenes and Salmonella were developed to demonstrate the application of iRISK for the estimation of risks and the impact of interventions for microbial hazards. iRISK was made available to the public at http://irisk.foodrisk.org in October 2012.

  19. Use of Multicriteria Risk Ranking of Zoonotic Diseases in a Developing Country: Case Study of Mongolia.

    PubMed

    McFadden, A M J; Muellner, P; Baljinnyam, Z; Vink, D; Wilson, N

    2016-03-01

    Many developing countries face significant health burdens associated with a high incidence of endemic zoonoses and difficulties in integrated control measures for both the human and animal populations. The objective of this study was to develop and apply a multicriteria ranking model for zoonoses in Mongolia, a country highly affected by zoonotic disease, to inform optimal resource allocation at the national level. Diseases were evaluated based on their impact on human health, livestock sector health and the wider society through affects on the economic value of livestock, as well as the feasibility of control in both the human and livestock population. Data on disease in Mongolia were collected from various government departments including the Mongolian State Central Laboratory, the Mongolian Department of Veterinary and Animal Breeding, the Mongolian Ministry of Health, Mongolian National Center for Communicable Diseases, the National Center for Zoonotic Disease and expert opinion from a workshop with a number of Mongolian Government officials and researchers. A combined score for both impact of the disease and feasibility of its control was calculated. Five zoonotic diseases were determined to be of high priority from this assessment (i.e. ovine brucellosis, echinococcosis (hydatids), rabies, anthrax and bovine brucellosis). The results supported some of the findings for high-priority diseases (namely brucellosis, rabies and anthrax) from a previous priority setting exercise carried out in Mongolia in 2011, but also identified and ranked additional animal diseases of public health importance. While the process of model development was largely Mongolian specific, the experience of developing and parameterizing this multicriteria ranking model could be replicated by other countries where zoonoses have substantive impacts on both animal and human health.

  20. Is There a Risk of Suburban Transmission of Malaria in Selangor, Malaysia?

    PubMed Central

    Braima, Kamil A.; Sum, Jia-Siang; Ghazali, Amir-Ridhwan M.; Muslimin, Mustakiza; Jeffery, John; Lee, Wenn-Chyau; Shaker, Mohammed R.; Elamin, Alaa-Eldeen M.; Jamaiah, Ibrahim; Lau, Yee-Ling; Rohela, Mahmud; Kamarulzaman, Adeeba; Sitam, Frankie; Mohd-Noh, Rosnida; Abdul-Aziz, Noraishah M.

    2013-01-01

    Background The suburban transmission of malaria in Selangor, Malaysia’s most developed and populous state still remains a concern for public health in this region. Despite much successful control efforts directed at its reduction, sporadic cases, mostly brought in by foreigners have continued to occur. In addition, cases of simian malaria caused by Plasmodium knowlesi, some with fatal outcome have caused grave concern to health workers. The aim of this study was to investigate the possibility of local malaria transmission in suburban regions of Selangor, which are adjacent to secondary rainforests. Findings A malaria survey spanning 7 years (2006 - 2012) was conducted in Selangor. A total of 1623 laboratory confirmed malaria cases were reported from Selangor’s nine districts. While 72.6% of these cases (1178/1623) were attributed to imported malaria (cases originating from other countries), 25.5% (414/1623) were local cases and 1.9% (31/1623) were considered as relapse and unclassified cases combined. In this study, the most prevalent infection was P. vivax (1239 cases, prevalence 76.3%) followed by P. falciparum (211, 13.0%), P. knowlesi (75, 4.6%), P. malariae (71, 4.4%) and P. ovale (1, 0.06%). Mixed infections comprising of P. vivax and P. falciparum were confirmed (26, 1.6%). Entomological surveys targeting the residences of malaria patients’ showed that the most commonly trapped Anopheles species was An. maculatus. No oocysts or sporozoites were found in the An. maculatus collected. Nevertheless, the possibility of An. maculatus being the malaria vector in the investigated locations was high due to its persistent occurrence in these areas. Conclusions Malaria cases reported in this study were mostly imported cases. However the co-existence of local cases and potential Plasmodium spp. vectors should be cause for concern. The results of this survey reflect the need of maintaining closely monitored malaria control programs and continuous extensive malaria

  1. Malaria risk perception, knowledge and prophylaxis practices among travellers of African ethnicity living in Paris and visiting their country of origin in sub-Saharan Africa.

    PubMed

    Pistone, T; Guibert, P; Gay, F; Malvy, D; Ezzedine, K; Receveur, M C; Siriwardana, M; Larouzé, B; Bouchaud, O

    2007-10-01

    An observational prospective cohort study assessed malaria risk perception, knowledge and prophylaxis practices among individuals of African ethnicity living in Paris and travelling to their country of origin to visit friends or relatives (VFR). The study compared two groups of VFR who had visited a travel clinic (TC; n=122) or a travel agency (TA; n=69) before departure. Of the 47% of VFR citing malaria as a health concern, 75% knew that malaria is mosquito-borne and that bed nets are an effective preventive measure. Perception of high malaria risk was greater in the TA group (33%) than in the TC group (7%). The availability of a malaria vaccine was mentioned by 35% of VFR, with frequent confusion between yellow fever vaccine and malaria prevention. Twenty-nine percent took adequate chemoprophylaxis with complete adherence, which was higher among the TC group (41%) than the TA group (12%). Effective antivector protection measures used were bed nets (16%), wearing long clothes at night (14%) and air conditioning (8%), with no differences between the study groups except in the use of impregnated bed nets (11% of the TC group and none of the TA group). Media coverage, malaria chemoprophylaxis repayment and cultural adaptation of preventive messages should be improved to reduce the high rate of inadequate malaria prophylaxis in VFR.

  2. Fetal Responses during Placental Malaria Modify the Risk of Low Birth Weight▿

    PubMed Central

    Kabyemela, Edward R.; Fried, Michal; Kurtis, Jonathan D.; Mutabingwa, Theonest K.; Duffy, Patrick E.

    2008-01-01

    Inflammation during placental malaria (PM) is associated with low birth weight (LBW), especially during the first pregnancy, but the relative contribution of maternal or fetal factors that mediate this effect remains unclear and the role of gamma interferon (IFN-γ) has been controversial. We examined the relationship of maternal and cord plasma levels of IFN-γ, tumor necrosis factor alpha, interleukin-10, ferritin, and leptin to birth weight for Tanzanian women delivering in an area where there is a high rate of malaria transmission. The placental levels of inflammatory cytokines, including IFN-γ, increased significantly during PM in primigravid and multigravid women but not in secundigravid women. PM also increased maternal peripheral levels of all inflammatory markers except IFN-γ but had strikingly little effect on cord levels of these proteins. In a multivariate analysis, placental IFN-γ was negatively associated (P = 0.01) and cord ferritin was positively associated (P < 0.0001) with birth weight in infected (PM-positive [PM+]) first-time mothers. This relationship was not observed in other mothers, consistent with the epidemiology of PM and disease. Cord leptin had a strong positive relationship with birth weight in offspring of PM-negative women (P = 0.02 to P < 0.0001) but not in offspring of PM+ women (all differences were not significant) in the three gravidity groups. The results confirmed that placental IFN-γ is related to LBW due to PM during first pregnancies and suggest that fetal ferritin plays a protective role. Because fetal cells are a source of placental IFN-γ and cord ferritin, the fetal response to PM may modify the risk of LBW. PMID:18212078

  3. Prevalence and risk factors of malaria among children in southern highland Rwanda.

    PubMed

    Gahutu, Jean-Bosco; Steininger, Christian; Shyirambere, Cyprien; Zeile, Irene; Cwinya-Ay, Neniling; Danquah, Ina; Larsen, Christoph H; Eggelte, Teunis A; Uwimana, Aline; Karema, Corine; Musemakweri, Andre; Harms, Gundel; Mockenhaupt, Frank P

    2011-05-18

    Increased control has produced remarkable reductions of malaria in some parts of sub-Saharan Africa, including Rwanda. In the southern highlands, near the district capital of Butare (altitude, 1,768 m), a combined community-and facility-based survey on Plasmodium infection was conducted early in 2010. A total of 749 children below five years of age were examined including 545 randomly selected from 24 villages, 103 attending the health centre in charge, and 101 at the referral district hospital. Clinical, parasitological, haematological, and socio-economic data were collected. Plasmodium falciparum infection (mean multiplicity, 2.08) was identified by microscopy and PCR in 11.7% and 16.7%, respectively; 5.5% of the children had malaria. PCR-based P. falciparum prevalence ranged between 0 and 38.5% in the villages, and was 21.4% in the health centre, and 14.9% in the hospital. Independent predictors of infection included increasing age, low mid-upper arm circumference, absence of several household assets, reported recent intake of artemether-lumefantrine, and chloroquine in plasma, measured by ELISA. Self-reported bed net use (58%) reduced infection only in univariate analysis. In the communities, most infections were seemingly asymptomatic but anaemia was observed in 82% and 28% of children with and without parasitaemia, respectively, the effect increasing with parasite density, and significant also for submicroscopic infections. Plasmodium falciparum infection in the highlands surrounding Butare, Rwanda, is seen in one out of six children under five years of age. The abundance of seemingly asymptomatic infections in the community forms a reservoir for transmission in this epidemic-prone area. Risk factors suggestive of low socio-economic status and insufficient effectiveness of self-reported bed net use refer to areas of improvable intervention.

  4. Potential malaria outbreak in Germany due to climate warming: risk modelling based on temperature measurements and regional climate models.

    PubMed

    Holy, Marcel; Schmidt, Gunther; Schröder, Winfried

    2011-03-01

    Climate warming can change the geographic distribution and intensity of the transmission of vector-borne diseases such as malaria. The transmitted parasites usually benefit from increased temperatures as both their reproduction and development are accelerated. Lower Saxony (northwestern Germany) has been a malaria region until the 1950s, and the vector species are still present throughout Germany. This gave reason to investigate whether a new autochthonous transmission could take place if the malaria pathogen was introduced again in Germany. The spatial distribution of potential temperature-driven malaria transmissions was investigated using the basic reproduction rate (R (0)) to model and geostatistically map areas at risk of an outbreak of tertian malaria based on measured (1961-1990, 1991-2007) and predicted (1991-2020, 2021-2050, 2051-2080) monthly mean air temperature data. From the computations, maps were derived showing that during the period 1961-1990, the seasonal transmission gate ranges from 0 to 4 months and then expands up to 5 months in the period 1991-2007. For the projection of future trends, the regional climate models REMO and WettReg were used each with two different scenarios (A1B and B1). Both modelling approaches resulted in prolonged seasonal transmission gates in the future, enabling malaria transmissions up to 6 months in the climate reference period 2051-2080 (REMO, scenario A1B). The presented risk prognosis is based on the R (0) formula for the estimation of the reproduction of the malaria pathogen Plasmodium vivax. The presented model focuses on mean air temperatures; thus, other driving factors like the distribution of water bodies (breeding habitats) or population density are not integrated. Nevertheless, the modelling presented in this study can help identify areas at risk and initiate prevention. The described findings may also help in the investigation and assessment of related diseases caused by temperature-dependent vectors

  5. Oil Spill Risk Assessment Model and the Ranking of Ports for Oil Spill Vulnerability.

    DTIC Science & Technology

    1995-06-01

    uniform guidance methodology based on risk assessment principles. The development of port specific oil spill risk assessment methodology is described in...based on the susceptibity to small, medium and large spills. The oil spill risk for a number of major U.S. ports has been calculated and presented. (AN)

  6. Plasmodium vivax Malaria in Pregnant Women in the Brazilian Amazon and the Risk Factors Associated with Prematurity and Low Birth Weight: A Descriptive Study

    PubMed Central

    Bôtto-Menezes, Camila; Silva dos Santos, Mônica Caroline; Lopes Simplício, Janicéia; Menezes de Medeiros, Jandira; Barroso Gomes, Kelly Cristina; de Carvalho Costa, Isabel Cristina; Batista-Silva, Eva; Teixeira do Nascimento, Cristiana; da Silva Chagas, Eda Cristina; Jardim Sardinha, José Felipe; Simões de Santana Filho, Franklin; Brock, Marianna

    2015-01-01

    Introduction Plasmodium vivax is the most prevalent malaria species in the American region. Brazil accounts for the higher number of the malaria cases reported in pregnant women in the Americas. This study aims to describe the characteristics of pregnant women with malaria in an endemic area of the Brazilian Amazon and the risk factors associated with prematurity and low birth weight (LBW). Methods/Principal Findings Between December 2005 and March 2008, 503 pregnant women with malaria that attended a tertiary health centre were enrolled and followed up until delivery and reported a total of 1016 malaria episodes. More than half of study women (54%) were between 20–29 years old, and almost a third were adolescents. The prevalence of anaemia at enrolment was 59%. Most women (286/503) reported more than one malaria episode and most malaria episodes (84.5%, 846/1001) were due to P. vivax infection. Among women with only P. vivax malaria, the risk of preterm birth and low birth weight decreased in multigravidae (OR, 0.36 [95% CI, 0.16–0.82]; p = 0.015 and OR 0.24 [95% CI, 0.10–0.58]; p = 0.001, respectively). The risk of preterm birth decreased with higher maternal age (OR 0.43 [95% CI, 0.19–0.95]; p = 0.037) and among those women who reported higher antenatal care (ANC) attendance (OR, 0.32 [95% CI, 0.15–0.70]; p = 0.005). Conclusion This study shows that P. vivax is the prevailing species among pregnant women with malaria in the region and shows that vivax clinical malaria may represent harmful consequences for the health of the mother and their offsprings particularly on specific groups such as adolescents, primigravidae and those women with lower ANC attendance. PMID:26675007

  7. Plasmodium vivax Malaria in Pregnant Women in the Brazilian Amazon and the Risk Factors Associated with Prematurity and Low Birth Weight: A Descriptive Study.

    PubMed

    Bôtto-Menezes, Camila; Silva Dos Santos, Mônica Caroline; Lopes Simplício, Janicéia; Menezes de Medeiros, Jandira; Barroso Gomes, Kelly Cristina; de Carvalho Costa, Isabel Cristina; Batista-Silva, Eva; Teixeira do Nascimento, Cristiana; da Silva Chagas, Eda Cristina; Jardim Sardinha, José Felipe; Simões de Santana Filho, Franklin; Brock, Marianna; Bardají, Azucena; Martínez-Espinosa, Flor Ernestina

    2015-01-01

    Plasmodium vivax is the most prevalent malaria species in the American region. Brazil accounts for the higher number of the malaria cases reported in pregnant women in the Americas. This study aims to describe the characteristics of pregnant women with malaria in an endemic area of the Brazilian Amazon and the risk factors associated with prematurity and low birth weight (LBW). Between December 2005 and March 2008, 503 pregnant women with malaria that attended a tertiary health centre were enrolled and followed up until delivery and reported a total of 1016 malaria episodes. More than half of study women (54%) were between 20-29 years old, and almost a third were adolescents. The prevalence of anaemia at enrolment was 59%. Most women (286/503) reported more than one malaria episode and most malaria episodes (84.5%, 846/1001) were due to P. vivax infection. Among women with only P. vivax malaria, the risk of preterm birth and low birth weight decreased in multigravidae (OR, 0.36 [95% CI, 0.16-0.82]; p = 0.015 and OR 0.24 [95% CI, 0.10-0.58]; p = 0.001, respectively). The risk of preterm birth decreased with higher maternal age (OR 0.43 [95% CI, 0.19-0.95]; p = 0.037) and among those women who reported higher antenatal care (ANC) attendance (OR, 0.32 [95% CI, 0.15-0.70]; p = 0.005). This study shows that P. vivax is the prevailing species among pregnant women with malaria in the region and shows that vivax clinical malaria may represent harmful consequences for the health of the mother and their offsprings particularly on specific groups such as adolescents, primigravidae and those women with lower ANC attendance.

  8. Building uncertainty into cost-effectiveness rankings: portfolio risk-return tradeoffs and implications for decision rules.

    PubMed

    O'Brien, B J; Sculpher, M J

    2000-05-01

    Current principles of cost-effectiveness analysis emphasize the rank ordering of programs by expected economic return (eg, quality-adjusted life-years gained per dollar expended). This criterion ignores the variance associated with the cost-effectiveness of a program, yet variance is a common measure of risk when financial investment options are appraised. Variation in health care program return is likely to be a criterion of program selection for health care managers with fixed budgets and outcome performance targets. Characterizing health care resource allocation as a risky investment problem, we show how concepts of portfolio analysis from financial economics can be adopted as a conceptual framework for presenting cost-effectiveness data from multiple programs as mean-variance data. Two specific propositions emerge: (1) the current convention of ranking programs by expected return is a special case of the portfolio selection problem in which the decision maker is assumed to be indifferent to risk, and (2) for risk-averse decision makers, the degree of joint risk or covariation in cost-effectiveness between programs will create incentives to diversify an investment portfolio. The conventional normative assumption of risk neutrality for social-level public investment decisions does not apply to a large number of health care resource allocation decisions in which health care managers seek to maximize returns subject to budget constraints and performance targets. Portfolio theory offers a useful framework for studying mean-variance tradeoffs in cost-effectiveness and offers some positive predictions (and explanations) of actual decision making in the health care sector.

  9. Risk ranking of bioaccessible metals from fly ash dissolved in simulated lung and gut fluids.

    PubMed

    Twining, John; McGlinn, Peter; Loi, Elaine; Smith, Kath; Gieré, Reto

    2005-10-01

    Power plant fly ash from two fuels, coal and a mixture of coal and shredded tires, were evaluated for trace metal solubility in simulated human lung and gut fluids (SLF and SGF, respectively) to estimate bioaccessibility. The proportion of bioaccessible to total metal ranged from zero (V) to 80% (Zn) for coal-derived ash in SLF and from 2 (Th) to 100% (Cu) for tire-derived fly ash in SGF. The tire-derived ash contained much more Zn. However, Zn ranked only 5th of the various toxic metals in SGF compared with international regulations for ingestion. On the basis of total concentrations, the metals closestto exceeding limits based on international regulations for inhalation were Cr, Pb, and Al. On dissolution in SLF, the most limiting metals were Pb, Cu, and Zn. For metals exposed to SGF there was no relative change in the top metal, Al, before and after dissolution but the second-ranked metal shifted from Pb to Ni. In most cases only a proportion of the total metal concentrations in either fly ash was soluble, and hence bioaccessible, in either biofluid. When considering the regulatory limits for inhalation of particulates, none of the metal concentrations measured were as hazardous as the fly ash particulates themselves. However, on the basis of the international ingestion regulations for Al, the maximum mass of fly ash that could be ingested is only 1 mg per day (10 mg based on bioaccessibility). It is possible that such a small mass could be consumed by exposed individuals or groups.

  10. Quality of life and the risk of contracting malaria by multivariate analysis in the Brazilian Amazon region

    PubMed Central

    2014-01-01

    Background The incidence of malaria in the Amazon basin is closely related to social inequalities, given that precarious economic and socio-environmental conditions represent favourable factors for the transmission of the disease in tropical regions, such as the Brazilian state of Pará. In the present study, an association was found between the variation in a quality of life index (QLI), based on the socioeconomic differences between the municipalities of this state, and the risk of contracting malaria, based on the Annual Parasitic Index (API), with the primary objective of providing guidelines for the development of effective strategies for the control of the disease. Methods The API scores for the years between 2003 and 2011 were collected from the Brazilian Ministry of Health’s DATASUS database, and socioeconomic data for the 143 municipalities of Pará were obtained from the 2010 census. The data were analysed using multivariate factorial and correspondence techniques. Results The QLI was calculated for each municipality, of which, 69.23% were classified as having a poor or regular quality of life. The municipalities with poor QLI scores also presented moderate to high rates of malaria, with probabilities of 80.97% and 95.13%, respectively, while those with good QLI scores had low rates of malaria, with a probability of 79.24%. The results indicated a concentration of malaria in the south-west of the state of Pará, with an increase of 8.82% in the incidence of the disease over the study period, and the northeastern and Marajó mesoregions, where there was an increase of over 90%. In south-eastern Pará, by contrast, there was a marked reduction (78%) in the incidence of the disease, reflecting the heterogeneous distribution of malaria among the different municipalities and mesoregions of the state, especially those with moderate to high risk of transmission. Conclusions These findings confirm that malaria is endemic to Pará and is typical of the state

  11. Screening and ranking framework (SRF) for geologic CO2 storagesite selection on the basis of HSE risk

    SciTech Connect

    Oldenburg, Curtis M.

    2006-11-27

    A screening and ranking framework (SRF) has been developedto evaluate potential geologic carbon dioxide (CO2) storage sites on thebasis of health, safety, and environmental (HSE) risk arising from CO2leakage. The approach is based on the assumption that CO2 leakage risk isdependent on three basic characteristics of a geologic CO2 storage site:(1) the potential for primary containment by the target formation; (2)the potential for secondary containment if the primary formation leaks;and (3) the potential for attenuation and dispersion of leaking CO2 ifthe primary formation leaks and secondary containment fails. Theframework is implemented in a spreadsheet in which users enter numericalscores representing expert opinions or published information along withestimates of uncertainty. Applications to three sites in Californiademonstrate the approach. Refinements and extensions are possible throughthe use of more detailed data or model results in place of propertyproxies.

  12. Rank Dynamics

    NASA Astrophysics Data System (ADS)

    Gershenson, Carlos

    Studies of rank distributions have been popular for decades, especially since the work of Zipf. For example, if we rank words of a given language by use frequency (most used word in English is 'the', rank 1; second most common word is 'of', rank 2), the distribution can be approximated roughly with a power law. The same applies for cities (most populated city in a country ranks first), earthquakes, metabolism, the Internet, and dozens of other phenomena. We recently proposed ``rank diversity'' to measure how ranks change in time, using the Google Books Ngram dataset. Studying six languages between 1800 and 2009, we found that the rank diversity curves of languages are universal, adjusted with a sigmoid on log-normal scale. We are studying several other datasets (sports, economies, social systems, urban systems, earthquakes, artificial life). Rank diversity seems to be universal, independently of the shape of the rank distribution. I will present our work in progress towards a general description of the features of rank change in time, along with simple models which reproduce it

  13. Risk-based ranking of dominant contributors to maritime pollution events

    SciTech Connect

    Wheeler, T.A. )

    1993-04-01

    This report describes a conceptual approach for identifying dominant contributors to risk from maritime shipping of hazardous materials. Maritime transportation accidents are relatively common occurrences compared to more frequently analyzed contributors to public risk. Yet research on maritime safety and pollution incidents has not been guided by a systematic, risk-based approach. Maritime shipping accidents can be analyzed using event trees to group the accidents into bins,' or groups, of similar characteristics such as type of cargo, location of accident (e.g., harbor, inland waterway), type of accident (e.g., fire, collision, grounding), and size of release. The importance of specific types of events to each accident bin can be quantified. Then the overall importance of accident events to risk can be estimated by weighting the events' individual bin importance measures by the risk associated with each accident bin. 4 refs., 3 figs., 6 tabs.

  14. Modelling the risk of being bitten by malaria vectors in a vector control area in southern Benin, west Africa.

    PubMed

    Moiroux, Nicolas; Bio-Bangana, Abdul S; Djènontin, Armel; Chandre, Fabrice; Corbel, Vincent; Guis, Hélène

    2013-03-15

    The diversity of malaria vector populations, expressing various resistance and/or behavioural patterns could explain the reduced effectiveness of vector control interventions reported in some African countries. A better understanding of the ecology and distribution of malaria vectors is essential to design more effective and sustainable strategies for malaria control and elimination. Here, we analyzed the spatio-temporal risk of the contact between humans and the sympatric An. funestus and both M and S molecular forms of An. gambiae s.s. in an area of Benin with high coverage of vector control measures with an unprecedented level of resolution. Presence-absence data for the three vectors from 1-year human-landing collections in 19 villages were assessed using binomial mixed-effects models according to vector control measures and environmental covariates derived from field and remote sensing data. After 8-fold cross-validations of the models, predictive maps of the risk of the contact between humans and the sympatric An. funestus and both molecular M and S forms of An. gambiae s.s. were computed. Model validations showed that the An. funestus, An. gambiae M form, and S form models provided an excellent (Area Under Curve>0.9), a good (AUC>0.8), and an acceptable (AUC>0.7) level of prediction, respectively. The distribution area of the probability of contact between human and An. funestus largely overlaps that of An. gambiae M form but this latter showed important seasonal variation. An. gambiae S form also showed seasonal variation but with different ecological preferences. Landscape data were useful to discriminate between the species' distributions. These results showed that available remote sensing data could help in predicting the human-vector contact for several species of malaria vectors at a village level scale. The predictive maps showed seasonal and spatial variations in the risk of human-vector contact for all three vectors. Such maps could help Malaria

  15. Evaluating local vegetation cover as a risk factor for malaria transmission: a new analytical approach using ImageJ

    PubMed Central

    2014-01-01

    Background In places where malaria transmission is unstable or is transmitted under hypoendemic conditions, there are periods where limited foci of cases still occur and people become infected. These residual “hot spots” are likely reservoirs of the parasite population and so are fundamental to the seasonal spread and decline of malaria. It is, therefore, important to understand the ecological conditions that permit vector mosquitoes to survive and forage in these specific areas. Features such as local waterways and vegetation, as well as local ecology, particularly nocturnal temperature, humidity, and vegetative sustainability, are important for modeling local mosquito behavior. Vegetation around a homestead likely provides refuge for outdoor resting of these insects and may be a risk factor for malaria transmission. Analysis of this vegetation can be done using satellite information and mapping programs, such as Google Earth, but manual quantification is difficult and can be tedious and subjective. A more objective method is required. Methods Vegetation cover in the environment is reasonably static, particularly in and around homesteads. In order to evaluate and enumerate such information, ImageJ, an image processing software, was used to analyse Google Earth satellite imagery. The number of plants, total amount of vegetation around a homestead and its percentage of the total area were calculated and related to homesteads where cases of malaria were recorded. Results Preliminary results were obtained from a series of field trials carried out in South East Zambia in the Choma and Namwala districts from a base at the Macha District Hospital. Conclusions This technique is objective, clear and simple to manipulate and has potential application to determine the role that vegetation proximal to houses may play in affecting mosquito behaviour, foraging and subsequent malaria incidence. PMID:24620929

  16. Development of a comparative risk ranking system for agents posing a bioterrorism threat to human or animal populations.

    PubMed

    Tomuzia, Katharina; Menrath, Andrea; Frentzel, Hendrik; Filter, Matthias; Weiser, Armin A; Bräunig, Juliane; Buschulte, Anja; Appel, Bernd

    2013-09-01

    Various systems for prioritizing biological agents with respect to their applicability as biological weapons are available, ranging from qualitative to (semi)quantitative approaches. This research aimed at generating a generic risk ranking system applicable to human and animal pathogenic agents based on scientific information. Criteria were evaluated and clustered to create a criteria list. Considering availability of data, a number of 28 criteria separated by content were identified that can be classified in 11 thematic areas or categories. Relevant categories contributing to probability were historical aspects, accessibility, production efforts, and possible paths for dispersion. Categories associated with impact are dealing with containment measures, availability of diagnostics, preventive and treatment measures in human and animal populations, impact on society, human and veterinary public health, and economic and ecological consequences. To allow data-based scoring, each criterion was described by at least 1 measure that allows the assignment of values. These values constitute quantities, ranges, or facts that are as explicit and precise as possible. The consideration of minimum and maximum values that can occur due to natural variations and that are often described in the literature led to the development of minimum and maximum criteria and consequently category scores. Missing or incomplete data, and uncertainty resulting therefrom, were integrated into the scheme via a cautious (but not overcautious) approach. The visualization technique that was used allows the description and illustration of uncertainty on the level of probability and impact. The developed risk ranking system was evaluated by assessing the risk originating from the bioterrorism threat of the animal pathogen bluetongue virus, the human pathogen Enterohemorrhagic Escherichia coli O157:H7, the zoonotic Bacillus anthracis, and Botulinum neurotoxin.

  17. Ranking games.

    PubMed

    Osterloh, Margit; Frey, Bruno S

    2015-02-01

    Research rankings based on bibliometrics today dominate governance in academia and determine careers in universities. Analytical approach to capture the incentives by users of rankings and by suppliers of rankings, both on an individual and an aggregate level. Rankings may produce unintended negative side effects. In particular, rankings substitute the "taste for science" by a "taste for publication." We show that the usefulness of rankings rests on several important assumptions challenged by recent research. We suggest as alternatives careful socialization and selection of scholars, supplemented by periodic self-evaluations and awards. The aim is to encourage controversial discourses in order to contribute meaningful to the advancement of science. © The Author(s) 2014.

  18. Predictive study on the risk of malaria spreading due to global warming

    SciTech Connect

    Ono, Masaji

    1996-12-31

    Global warming will bring about a temperature elevation, and the habitat of vectors of infectious diseases, such as malaria and dengue fever, will spread into subtropical or temperate zone. The purpose of this study is to simulate the spreading of these diseases through reexamination of existing data and collection of some additional information by field survey. From these data, the author will establish the relationship between meteorological conditions, vector density and malaria occurrence. And then he will simulate and predict the malaria epidemics in case of temperature elevation in southeast Asia and Japan.

  19. Investigating malaria risk in the northern region of Nigeria using satellite imagery

    NASA Astrophysics Data System (ADS)

    Emetere, M. E.; Nikouravan, Bijan; Olawole, O. F.

    2015-08-01

    The dynamics of infectious diseases are dependent on salient environment and climate factors which are directly proportional to its transmission. Malaria is a common disease of typical tropics of the West African sub-region. The influences of malaria transmission via meteorological and environmental parameters were examined. Remotely sensed parameters i.e. skin temperature, sensible heat flux, latent heat flux and total precipitation were obtained from the NASA-MERRA. The results show that the meteorological and environmental parameters of northern Nigeria favour the long malaria dominance.

  20. Risk ranking of LANL nuclear material storage containers for repackaging prioritization.

    PubMed

    Smith, Paul H; Jordan, Hans; Hoffman, Jenifer A; Eller, P Gary; Balkey, Simon

    2007-05-01

    Safe handling and storage of nuclear material at U.S. Department of Energy facilities relies on the use of robust containers to prevent container breaches and subsequent worker contamination and uptake. The U.S. Department of Energy has no uniform requirements for packaging and storage of nuclear materials other than those declared excess and packaged to DOE-STD-3013-2000. This report describes a methodology for prioritizing a large inventory of nuclear material containers so that the highest risk containers are repackaged first. The methodology utilizes expert judgment to assign respirable fractions and reactivity factors to accountable levels of nuclear material at Los Alamos National Laboratory. A relative risk factor is assigned to each nuclear material container based on a calculated dose to a worker due to a failed container barrier and a calculated probability of container failure based on material reactivity and container age. This risk-based methodology is being applied at LANL to repackage the highest risk materials first and, thus, accelerate the reduction of risk to nuclear material handlers.

  1. Basic sanitation, socioeconomic conditions, and degree of risk for the presence and maintenance of malaria in a low-transmission area in the Brazilian Amazon.

    PubMed

    Monteiro, Thais Hetierre Abreu; Chaves, Tânia do Socorro Souza; Matos, Haroldo José de; Sofffiatti, Nelson Fernando de Lisboa; Guimarães, Ricardo José de Paula Souza e; Guimarães, Luis Henrique Rocha; Ventura, Ana Maria Revoredo; Machado, Ricardo Luiz Dantas

    2015-01-01

    This study aimed to evaluate basic sanitation and socioeconomic indicators, reported cases of malaria, and risk of contracting malaria in the Ananindeua municipality, State of Pará. Data on basic sanitation and socioeconomic dimensions were taken from the Brazilian Institute of Geography and Statistics [ Instituto Brasileiro de Geografia e Estatística (IBGE)] 2010 census. Epidemiological malaria information was taken from the Epidemiological Malaria Surveillance Information System [ Sistema de Informação de Vigilância Epidemiológica de Malária (SIVEP/Malaria)], between 2003 and 2013 of the Ministry of Health and from the SIVEP/Malaria forms of the municipality's Endemic Diseases Unit for 2,013 cases. Our data do not confirm the correlation among indicators of basic sanitation, socioeconomic conditions, and water supply with malaria cases. Of the 1,557 cases evaluated, most were caused by Plasmodium vivax , with rare cases of Plasmodium falciparum and mixed infections. There were 756 notifications in 2003. The number of reported cases was sharply reduced between 2006 and 2012, but a 142-case outbreak occurred in 2013. Ananindeua municipality's Annual Parasite Index indicated low risk in 2003 and no risk in other years, and the 2,013 cases were predominantly male individuals aged ≥40 years. Our data confirm the non-endemicity of malaria in the Ananindeua municipality, as the Annual Parasite Indices described for the years 2004-2013 classify it as a risk-free area. However, the 2013 outbreak indicates the need to strengthen prevention, surveillance, and control activities to reduce the risk of new outbreaks and consequent economic and social impacts on the population.

  2. Ranking the contributions of commercial fish and shellfish varieties to mercury exposure in the United States: implications for risk communication.

    PubMed

    Groth, Edward

    2010-04-01

    Fish and shellfish have important nutritional benefits, and US per capita seafood consumption has increased substantially since 2002. Recent research has reinforced concerns about adverse effects of methylmercury exposure, suggesting that methylmercury doses associated with typical US rates of fish consumption may pose measurable risks, with no threshold. These converging trends create a need to improve risk communication about fish consumption and mercury. The analysis performed here identifies the relative importance of different fish and shellfish as sources of mercury in the US seafood supply and proposes improved consumer advice, so that the public can benefit from fish consumption while minimizing mercury exposure. I have quantified contributions to total mercury in the US seafood supply by 51 different varieties of fish and shellfish, then ranked and sorted the 51 varieties in terms of relative impact. Except for swordfish, most fish with the highest mercury levels are relatively minor contributors to total inputs. Tuna (canned light, canned albacore and fresh/frozen varieties) accounts for 37.4 percent of total mercury inputs, while two-thirds of the seafood supply and nine of the 11 most heavily consumed fish and shellfish are low or very low in mercury. Substantial improvement in risk communication about mercury in fish and seafood is needed; in particular, several population subsets need better guidance to base their seafood choices more explicitly on mercury content. I have sorted the 51 seafood varieties into six categories based on mercury levels, as a framework for improving risk communication in this regard.

  3. Clearance of Asymptomatic P. falciparum Infections Interacts with the Number of Clones to Predict the Risk of Subsequent Malaria in Kenyan Children

    PubMed Central

    Liljander, Anne; Bejon, Philip; Mwacharo, Jedidah; Kai, Oscar; Ogada, Edna; Peshu, Norbert; Marsh, Kevin; Färnert, Anna

    2011-01-01

    Background Protective immunity to malaria is acquired after repeated infections in endemic areas. Asymptomatic multiclonal P. falciparum infections are common and may predict host protection. Here, we have investigated the effect of clearing asymptomatic infections on the risk of clinical malaria. Methods Malaria episodes were continuously monitored in 405 children (1–6 years) in an area of moderate transmission, coastal Kenya. Blood samples collected on four occasions were assessed by genotyping the polymorphic P. falciparum merozoite surface protein 2 using fluorescent PCR and capillary electrophoresis. Following the second survey, asymptomatic infections were cleared with a full course of dihydroartemisinin. Results Children who were parasite negative by PCR had a lower risk of subsequent malaria regardless of whether treatment had been given. Children with ≥2 clones had a reduced risk of febrile malaria compared with 1 clone after clearance of asymptomatic infections, but not if asymptomatic infections were not cleared. Multiclonal infection was associated with an increased risk of re-infection after drug treatment. However, among the children who were re-infected, multiclonal infections were associated with a shift from clinical malaria to asymptomatic parasitaemia. Conclusion The number of clones was associated with exposure as well as blood stage immunity. These effects were distinguished by clearing asymptomatic infection with anti-malarials. Exposure to multiple P. falciparum infections is associated with protective immunity, but there appears to be an additional effect in untreated multiclonal infections that offsets this protective effect. PMID:21383984

  4. Use of an Anopheles Salivary Biomarker to Assess Malaria Transmission Risk Along the Thailand-Myanmar Border.

    PubMed

    Ya-Umphan, Phubeth; Cerqueira, Dominique; Parker, Daniel M; Cottrell, Gilles; Poinsignon, Anne; Remoue, Franck; Brengues, Cecile; Chareonviriyaphap, Theeraphap; Nosten, Francois; Corbel, Vincent

    2017-02-01

    The modalities of malaria transmission along the Thailand-Myanmar border are poorly understood. Here we address the relevance of using a specific Anopheles salivary biomarker to measure the risk among humans of exposure to Anopheles bites. Serologic surveys were conducted from May 2013 to December 2014 in 4 sentinel villages. More than 9400 blood specimens were collected in filter papers from all inhabitants at baseline and then every 3 months thereafter, for up to 18 months, for analysis by enzyme-linked immunosorbent assay. The relationship between the intensity of the human antibody response and entomological indicators of transmission (human biting rates and entomological inoculation rates [EIRs]) was studied using a multivariate 3-level mixed model analysis. Heat maps for human immunoglobulin G (IgG) responses for each village and survey time point were created using QGIS 2.4. The levels of IgG response among participants varied significantly according to village, season, and age (P<.001) and were positively associated with the abundance of total Anopheles species and primary malaria vectors and the EIR (P<.001). Spatial clusters of high-IgG responders were identified across space and time within study villages. The gSG6-P1 biomarker has great potential to address the risk of transmission along the Thailand-Myanmar border and represents a promising tool to guide malaria interventions.

  5. Disentangling the effects of forage, social rank, and risk on movement autocorrelation of elephants using Fourier and wavelet analyses

    PubMed Central

    Wittemyer, George; Polansky, Leo; Douglas-Hamilton, Iain; Getz, Wayne M.

    2008-01-01

    The internal state of an individual—as it relates to thirst, hunger, fear, or reproductive drive—can be inferred by referencing points on its movement path to external environmental and sociological variables. Using time-series approaches to characterize autocorrelative properties of step-length movements collated every 3 h for seven free-ranging African elephants, we examined the influence of social rank, predation risk, and seasonal variation in resource abundance on periodic properties of movement. The frequency domain methods of Fourier and wavelet analyses provide compact summaries of temporal autocorrelation and show both strong diurnal and seasonal based periodicities in the step-length time series. This autocorrelation is weaker during the wet season, indicating random movements are more common when ecological conditions are good. Periodograms of socially dominant individuals are consistent across seasons, whereas subordinate individuals show distinct differences diverging from that of dominants during the dry season. We link temporally localized statistical properties of movement to landscape features and find that diurnal movement correlation is more common within protected wildlife areas, and multiday movement correlations found among lower ranked individuals are typically outside of protected areas where predation risks are greatest. A frequency-related spatial analysis of movement-step lengths reveal that rest cycles related to the spatial distribution of critical resources (i.e., forage and water) are responsible for creating the observed patterns. Our approach generates unique information regarding the spatial-temporal interplay between environmental and individual characteristics, providing an original approach for understanding the movement ecology of individual animals and the spatial organization of animal populations. PMID:19060207

  6. Spatial heterogeneity and temporal evolution of malaria transmission risk in Dakar, Senegal, according to remotely sensed environmental data

    PubMed Central

    2010-01-01

    Background The United Nations forecasts that by 2050, more than 60% of the African population will live in cities. Thus, urban malaria is considered an important emerging health problem in that continent. Remote sensing (RS) and geographic information systems (GIS) are useful tools for addressing the challenge of assessing, understanding and spatially focusing malaria control activities. The objectives of the present study were to use high spatial resolution SPOT (Satellite Pour l'Observation de la Terre) satellite images to identify some urban environmental factors in Dakar associated with Anopheles arabiensis densities, to assess the persistence of these associations and to describe spatial changes in at-risk environments using a decadal time scale. Methods Two SPOT images from the 1996 and 2007 rainy seasons in Dakar were processed to extract environmental factors, using supervised classification of land use and land cover, and a calculation of NDVI (Normalized Difference Vegetation Index) and distance to vegetation. Linear regressions were fitted to identify the ecological factors associated with An. arabiensis aggressiveness measured in 1994-97 in the South and centre districts of Dakar. Risk maps for populated areas were computed and compared for 1996 and 2007 using the results of the statistical models. Results Almost 60% of the variability in anopheline aggressiveness measured in 1994-97 was explained with only one variable: the built-up area in a 300-m radius buffer around the catching points. This association remained stable between 1996 and 2007. Risk maps were drawn by inverting the statistical association. The total increase of the built-up areas in Dakar was about 30% between 1996 and 2007. In proportion to the total population of the city, the population at high risk for malaria fell from 32% to 20%, whereas the low-risk population rose from 29 to 41%. Conclusions Environmental data retrieved from high spatial resolution SPOT satellite images were

  7. Psychosomatics of malaria.

    PubMed

    Houghton, D L

    1980-03-01

    Cerebral malaria with psychosomatic manifestations is one aspect of malaria which may be mistaken for mental illness. However, the psychosomatic aspects of the disease also relate to the biological, psychological and social influences which may determine changes in disease incidence and distribution. The history of the Global Malaria Eradication Campaign and the resurgence of malaria in many countries of the world have influenced attitudes and the professional milieu in which present day malaria control programmes seek to operate. The individual in a malarious area may obstruct malaria control operations by refusing to allow indoor spraying or to take prophylactic medication. Cultural beliefs often described the history of malaria in a community and the way in which the community had come to terms with this disease. Socio-economic development and population movement may disturb this equilibrium and result in a rise in malaria incidence. Behavioural habits may increase malaria risk and the degree to which the community is prepared to become involved in malaria control may influence its experience with the disease.

  8. Malaria prophylaxis and guidelines.

    PubMed

    Calleri, Guido

    2014-10-01

    Malaria prophylaxis recommendations issued by different health authorities in Europe are inhomogeneous, and so is the opinion of experts, but a general trend towards reducing its use is evident, and prescribers apparently adhere more easily to more restrictive recommendations. A new Italian guideline has been produced, looking both at scientific evidence (data on malaria risk and drugs' side effects) and at the opinion of experts (surveys and previously issued recommendations). Collecting data on imported malaria, stating a clear methodology and introduce a discussion at international level should be the next goals in order to homogenise recommendations for malaria prophylaxis in Europe.

  9. 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

  10. Social norm influences on evaluations of the risks associated with alcohol consumption: applying the rank-based decision by sampling model to health judgments.

    PubMed

    Wood, Alex M; Brown, Gordon D A; Maltby, John

    2012-01-01

    The research first tested whether perceptions of other people's alcohol consumption influenced drinkers' perceptions of the riskiness of their own consumption. Second, the research tested how such comparisons are made-whether, for example, people compare their drinking to the 'average' drinker's or 'rank' their consumption amongst other people's. The latter untested possibility, suggested by the recent Decision by Sampling Model of judgment, would imply different cognitive mechanisms and suggest that information should be presented differently to people in social norm interventions. Study 1 surveyed students who provided information on (a) their own drinking, (b) their perceptions of the distribution of drinking in the UK and (c) their perceived risk of various alcohol-related disorders. Study 2 experimentally manipulated the rank of 'target' units of alcohol within the context of units viewed simultaneously. In both studies, the rank of an individual's drinking in a context of other drinkers predicted perceptions of developing alcohol-related disorders. There was no evidence for the alternative hypothesis that people compared with the average of other drinkers' consumptions. The position that subjects believed they occupied in the ranking of other drinkers predicted their perceived risk, and did so as strongly as how much they actually drank. Drinking comparisons are rank-based, which is consistent with other judgments in social, emotional and psychophysical domains. Interventions should be designed to work with people's natural ways of information processing, through providing clients with information on their drinking rank rather than how their drinking differs from the average.

  11. Occupational malaria and health risk among select occupational health care employee groups in an urban hospital at Tirupati, A.P.

    PubMed

    Rajasekhar, M; Nandakumar, N V

    2000-01-01

    Epidemiological studies on occupational environments are very meagre in the developing countries like India. For this reason an attempt was made in the present investigation to see the occupational risk of malaria among health care workers of Sri Venkateswara Ramnarayan Ruia Government General Hospital (SVRRGGH), Tirupati, Andhra Pradesh. The cohort studies revealed association between exposure to occupational (hospital) environment and malaria among hospital staff. Retrospective cohort studies were made. 1,454 subjects namely hospital staff exposed to occupational environment included civil assistant surgeons and physicians, the students of medicine, the students of nursing, permanent nursing staff and the class IV employees (class IV included janitorial, male nursing orderlies, female nursing orderlies, attenders, laundry workers and the rest). Retrospective epidemiological studies were carried out for four years on the cohorts and the hospital staff. The data showed statistically significant relative risk and attributable risk for malaria. Physicians and civil assistant surgeons showed no incidence of malaria. The relative risk for malaria in the class IV employees was 1.27, 0, 5.8 and 2.9 for the years 1995-98. The students of nursing showed 4.2, 2.42, 3.3 and 0 relative risk for malaria, whereas the students of medicine showed 2, 2, 2 and 1.6 for the years 1995 to 1998. The attributable risk was ranged from 21.76-82.70, 58.75-76.17, 50-80 for the class IV employees, the students of nursing and the students of medicine retrospectively. These results provide an evidence for an association between occupational environment and malaria for the hospital staff and is more prevalent among certain groups of the hospital staff.

  12. Special infectious disease risks of expatriates and long-term travelers in tropical countries. Part I: malaria.

    PubMed

    Toovey, Stephen; Moerman, Filip; van Gompel, Alfons

    2007-01-01

    Malaria risk is dependent upon the entomological inoculation rate actually faced by the long-term traveler. Risk is cumulative, increases with duration of exposure, is greatest in rural and periurban areas, and least in urban centers. Risk may be zero in some urban centers, especially during dry seasons. Chemoprophylaxis compliance is hindered by the high adverse event rate often reported by users, is often suboptimal in expatriates, and decreases with duration of stay. Compliance with personal protection measures may also be suboptimal, and use of insecticide-treated nets and effective repellents should be encouraged. Alternative strategies to mitigate risk include seasonal chemoprophylaxis, nonuse of chemoprophylaxis with rapid treatment, self-testing, self-treatment where competent care and quality drugs are unavailable, and vector control. Choice of strategies will depend upon assessment of actual risk and likely compliance, with a combination of measures usually appropriate.

  13. The risk of imported malaria in security forces personnel returning from overseas missions in the context of prevention of re-introduction of malaria to Sri Lanka.

    PubMed

    Fernando, Sumadhya Deepika; Dharmawardana, Priyani; Semege, Saveen; Epasinghe, Geetha; Senanayake, Niroshana; Rodrigo, Chaturaka; Premaratne, Risintha

    2016-03-08

    Sri Lanka is a malaria-free country. However it remains surrounded by countries with endemic malaria transmission. Since the last indigenous case of malaria was reported in October 2012, only imported malaria cases have been diagnosed with 36 cases detected in 2015, which includes 17 cases each of Plasmodium vivax and Plasmodium falciparum and two cases of Plasmodium ovale. This study investigated the knowledge and practices regarding malaria chemoprophylaxis among all the Sri Lankan security forces personnel returning from peacekeeping missions in malaria endemic countries over a 7 month period. Adherence to other malaria prevention measures, occurrence of adverse events and incident cases of malaria were also recorded maintaining the anonymity of the respondents. Potential associations for non-compliance were studied. Interviews were carried out with 559 security forces personnel returning home from foreign deployments in malaria-endemic regions (males: 550, 98.4 %). The majority (553, 98.9 %) was well aware of the need for chemoprophylaxis during the overseas stay and its regular use as prescribed. The overall adherence to chemoprophylaxis was good with 78.7 % (440/559) reporting regular, as prescribed, use. Having better educational qualifications, being female, being prescribed mefloquine, having fever during deployment and belonging to a security force other than the army were significantly associated with poor compliance (p < 0.05). The study reveals that knowledge regarding malaria chemoprophylaxis among Sri Lankan security forces personnel serving abroad was good, a fact that may have contributed to absence/extremely low incidence of malaria during deployment.

  14. U.S. Natural Gas Storage Risk-Based Ranking Methodology and Results

    SciTech Connect

    Folga, Steve; Portante, Edgar; Shamsuddin, Shabbir; Tompkins, Angeli; Talaber, Leah; McLamore, Mike; Kavicky, Jim; Conzelmann, Guenter; Levin, Todd

    2016-10-01

    This report summarizes the methodology and models developed to assess the risk to energy delivery from the potential loss of underground gas storage (UGS) facilities located within the United States. The U.S. has a total of 418 existing storage fields, of which 390 are currently active. The models estimate the impacts of a disruption of each of the active UGS facilities on their owners/operators, including (1) local distribution companies (LDCs), (2) directly connected transporting pipelines and thus on the customers in downstream States, and (3) third-party entities and thus on contracted customers expecting the gas shipment. Impacts are measured across all natural gas customer classes. For the electric sector, impacts are quantified in terms of natural gas-fired electric generation capacity potentially affected from the loss of a UGS facility. For the purpose of calculating the overall supply risk, the overall consequence of the disruption of an UGS facility across all customer classes is expressed in terms of the number of expected equivalent residential customer outages per year, which combines the unit business interruption cost per customer class and the estimated number of affected natural gas customers with estimated probabilities of UGS disruptions. All models and analyses are based on publicly available data. The report presents a set of findings and recommendations in terms of data, further analyses, regulatory requirements and standards, and needs to improve gas/electric industry coordination for electric reliability.

  15. 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

  16. [Epidemiology of imported malaria and entomological study of breeding sites of potential risk areas in the province of Khemisset (Morocco)].

    PubMed

    Larhbali, Y; Belghyti, D; El Guamri, Y; Lahlou, O; El Kharrim, K; Kirami, A; Khamri, Z

    2014-01-01

    No case of autochthonous malaria has been detected in Morocco since 2004. This achievement is due to a national strategy to combat the disease by appropriate and well-organized disease detection and treatment, as well as control of the mosquito vector of the disease, the female Anopheles mosquito. Nonetheless, imported malaria cases have been increasing (75 in 2007), due to the rise in international travel and migration from countries where the disease is endemic. This work is divided into two parts: the first part is a retrospective study of the cases of imported malaria identified by optical microscopy in the Laboratory of Medical Entomology of the Khemisset Provincial Delegation of Health from 2000 to 2010. The second part is an entomological study conducted in 2010 of the Culicidae insect family, especially the Anopheles genus. The results show that of 176,457 requests for parasite testing, 14 were positive. All positive samples came from men older than 23 years. The cases identified are imported from two African countries: the Democratic Republic of Congo (86%) and Ivory Coast (14%). The years of high incidence were 2003 with four cases and 2000, 2004 and 2006 with two cases. The species found are Plasmodium falciparum in 13 cases (93%) and Plasmodium ovale in one case (7%). The vector of autochthonous malaria, which was eliminated in 2004, is Anopheles (Anopheles) labranchiae Fallerouni 1926, and it was the dominant species found in our entomological study (424 larvae). The other species were found in breeding sites in potential at-risk locations in the study area.

  17. 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.

  18. Congenital malaria in China.

    PubMed

    Tao, Zhi-Yong; Fang, Qiang; Liu, Xue; Culleton, Richard; Tao, Li; Xia, Hui; Gao, Qi

    2014-03-01

    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. 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 with antimalarial drugs such as chloroquine

  19. 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

  20. Low and Declining Risk for Malaria in Visitors to Indonesia: A Review of Local Indonesian and European Travelers' Data and a Suggestion for New Prophylactic Guidelines.

    PubMed

    Johansson Århem, Katarina M; Gysin, Nicole; Nielsen, Henrik V; Surya, Asik; Hellgren, Urban

    2015-01-01

    The world's malaria map is constantly changing and with it the risk for travelers to contract malaria. While some efforts to appreciate the malaria situation for indigenous populations in Indonesia have been made recently, there is only sparse data in the literature on the risk for travelers to Indonesia. Data were collected from the Indonesian Ministry of Health (MoH), the World Health Organization (WHO), the Indonesian official statistics website Badan Pusat Statistik (BPS), and from the different European national surveillance bodies. Finally, a comparison between recent official guidelines for prevention of malaria in travelers from Germany, the United States, the UK, and from WHO was done. Data from Denmark, Germany, Sweden and Switzerland show a steady decline of imported cases of malaria from Indonesia from 1997 to 2013, with a leveling off during the last few years. In our study material, the Plasmodium falciparum incidence 2009 to 2013 was 0.35 cases per 100,000 visits and the Plasmodium vivax incidence 1.3 cases per 100,000 visits, with a 95% confidence interval of 0.1-0.9 and 0.7-2.2, respectively. Indonesian data also show a decline of malaria cases-the Annual Parasite Index (API) for all species of malaria has decreased from 4.68 cases per 1,000 inhabitants in 1990 to 1.38 cases per 1,000 inhabitants in 2013. Based on these data updated recommendations for malaria prophylaxis in travelers to Indonesia are suggested. © 2015 International Society of Travel Medicine.

  1. Mapping the Risks of Malaria, Dengue and Influenza Using Satellite Data

    NASA Astrophysics Data System (ADS)

    Kiang, R. K.; Soebiyanto, R. P.

    2012-07-01

    It has long been recognized that environment and climate may affect the transmission of infectious diseases. The effects are most obvious for vector-borne infectious diseases, such as malaria and dengue, but less so for airborne and contact diseases, such as seasonal influenza. In this paper, we examined the meteorological and environmental parameters that influence the transmission of malaria, dengue and seasonal influenza. Remotely sensed parameters that provide such parameters were discussed. Both statistical and biologically inspired, processed based models can be used to model the transmission of these diseases utilizing the remotely sensed parameters as input. Examples were given for modelling malaria in Thailand, dengue in Indonesia, and seasonal influenza in Hong Kong.

  2. Environmental Risk Evaluation System – An Approach to Ranking Risk of Ocean Energy Development on Coastal and Estuarine Environments

    SciTech Connect

    Copping, Andrea E.; Hanna, Luke A.; Van Cleve, Frances B.; Blake, Kara M.; Anderson, Richard M.

    2015-01-01

    Deployment and operation of ocean energy devices does not represent the first foray into industrialization of the oceans; shipping, nearshore development, waste disposal, subsea mining, oil and gas extraction, and large-scale commercial fishing all coexist in various states of equilibrium with the marine environment. In most cases these industries were developed without a clear understanding of the likely outcomes of large-scale development. In virtually every country where the harvest of ocean energy is emerging, regulators and stakeholders require that the industry examine potential effects of devices, minimize the footprint of effects, and provide management measures that either avoid the impacts or mitigate to further reduce the residual impacts. The ERES analysis is based on scenarios that are consistent with sequences of events that lead to adverse impacts, distinguishing between episodic, intermittent, and chronic risks. In the context of ocean energy development, an episodic scenario might involve the exceedingly rare but potentially devastating event of an oil spill from vessels caused by the presence of the device, while vulnerable receptors are present; understanding the risk of such a scenario involves determining the probability of the occurrence by examining factors such as the petroleum content of ocean energy devices, the vessel traffic volume and the proximity of shipping lanes to the ocean energy devices, the reliability of the control measures to avoid an episodic event, and the likely presence of seabirds, marine mammals, or fish that may be affected by oil. In contrast, chronic risk scenarios involve events or circumstances that are continuous, so that risk characterization involves assessing only the severity of the consequences. An example of a chronic risk scenario might be the toxicity to marine organisms due to low-level chemical releases from anti-biofouling paints and coatings that may be used on devices, and the effect that the level of

  3. Prevalence of Malaria Infection and Risk Factors Associated with Anaemia among Pregnant Women in Semiurban Community of Hazaribag, Jharkhand, India.

    PubMed

    Sohail, Mohammad; Shakeel, Shayan; Kumari, Shweta; Bharti, Aakanksha; Zahid, Faisal; Anwar, Shadab; Singh, Krishn Pratap; Islam, Mazahirul; Sharma, Ajay Kumar; Lata, Sneh; Ali, Vahab; Adak, Tridibes; Das, Pradeep; Raziuddin, Mohammad

    2015-01-01

    The escalating burden, pathogenesis, and clinical sequel of malaria during pregnancy have combinatorial adverse impact on both mother and foetus that further perplexed the situation of diagnosis, treatment, and prevention. This prompted us to evaluate the status of population at risk of MIP in Hazaribag, Jharkhand, India. Cross-sectional study was conducted over a year at Sadar Hospital, Hazaribag. Malaria was screened using blood smear and/or RDT. Anaemia was defined as haemoglobin concentration. Pretested questionnaires were used to gather sociodemographic, clinical, and obstetrical data. The prevalence of MIP was 5.4% and 4.3% at ANC and DU, and 13.2% malaria was in women without pregnancy. Interestingly, majority were asymptomatically infected with P. vivax (over 85%) at ANC and DU. Peripheral parasitemia was significantly associated with fever within past week, rural origin of subjects, and first/second pregnancies in multivariate analysis, with the highest risk factor associated with fever followed by rural residence. Strikingly in cohort, anaemia was prevalent in 86% at ANC as compared to 72% at DU, whereas severe anaemia was 13.6% and 7.8% at ANC and DU. Even more anaemia prevalence was observed in MIP group (88% and 89% at ANC and DU), whereas severe anaemia was 23% and 21%, respectively. In view of observed impact of anaemia, parasitemia and asymptomatic infection of P. vivax during pregnancy and delivery suggest prompt diagnosis regardless of symptoms and comprehensive drug regime should be offered to pregnant women in association with existing measures in clinical spectrum of MIP, delivery, and its outcome.

  4. Prevalence of Malaria Infection and Risk Factors Associated with Anaemia among Pregnant Women in Semiurban Community of Hazaribag, Jharkhand, India

    PubMed Central

    Sohail, Mohammad; Shakeel, Shayan; Kumari, Shweta; Bharti, Aakanksha; Zahid, Faisal; Anwar, Shadab; Singh, Krishn Pratap; Islam, Mazahirul; Sharma, Ajay Kumar; Lata, Sneh; Ali, Vahab; Adak, Tridibes; Das, Pradeep; Raziuddin, Mohammad

    2015-01-01

    The escalating burden, pathogenesis, and clinical sequel of malaria during pregnancy have combinatorial adverse impact on both mother and foetus that further perplexed the situation of diagnosis, treatment, and prevention. This prompted us to evaluate the status of population at risk of MIP in Hazaribag, Jharkhand, India. Cross-sectional study was conducted over a year at Sadar Hospital, Hazaribag. Malaria was screened using blood smear and/or RDT. Anaemia was defined as haemoglobin concentration. Pretested questionnaires were used to gather sociodemographic, clinical, and obstetrical data. The prevalence of MIP was 5.4% and 4.3% at ANC and DU, and 13.2% malaria was in women without pregnancy. Interestingly, majority were asymptomatically infected with P. vivax (over 85%) at ANC and DU. Peripheral parasitemia was significantly associated with fever within past week, rural origin of subjects, and first/second pregnancies in multivariate analysis, with the highest risk factor associated with fever followed by rural residence. Strikingly in cohort, anaemia was prevalent in 86% at ANC as compared to 72% at DU, whereas severe anaemia was 13.6% and 7.8% at ANC and DU. Even more anaemia prevalence was observed in MIP group (88% and 89% at ANC and DU), whereas severe anaemia was 23% and 21%, respectively. In view of observed impact of anaemia, parasitemia and asymptomatic infection of P. vivax during pregnancy and delivery suggest prompt diagnosis regardless of symptoms and comprehensive drug regime should be offered to pregnant women in association with existing measures in clinical spectrum of MIP, delivery, and its outcome. PMID:26783526

  5. Prevalence soil transmitted helminthiasis and malaria co-infection among pregnant women and risk factors in Gilgel Gibe Dam area, southwest Ethiopia.

    PubMed

    Getachew, Million; Tafess, Ketema; Zeynudin, Ahmed; Yewhalaw, Delenesaw

    2013-07-09

    Malaria and Soil Transmitted Helminthiasis (STH) are co-endemic and major public health problems in Ethiopia. The aim of the study was to assess the prevalence of malaria and STHs co-infection and to determine the association risk factors. A cross-sectional community based study was conducted on 388 pregnant women living in three districts around Gilgel Gibe Dam area, southwestern Ethiopia. Socio-demographic and socio-economic data, single stool sample and blood sample were collected from each participant. The prevalence of STH and malaria was 159 (41%) and 45 (11.6%), respectively and the prevalence of STHs/malaria co-infection was 30 (7.7%). Hookworm was the most prevalent 114 (29.4%) soil transmitted helminthiasis infection followed by Ascaris lumbricoides (A. lumbricoides) 58 (15%) and Trichuris trichiura (T. trichiura) 13 (3.4%). Habit of eating soil (Adjusted Odds Ratio (AOR) = 4.64, 95% CI: 1.50-14.36, P=0.008), presence of stagnant water near study participants' house (AOR=2.99, 95% CI: 1.28-6.99, P=0.012) and habit of using human feces as a fertilizer (AOR= 5.34, 95% CI: 1.99-14.28, P<0.001) were found to be significantly associated with malaria and STH co-infection among the pregnant women. Hookworm parasitic load was positively correlated with malaria parasitic load (r = 0.299, P<0.001) while A. lumbricoides parasitic load was negatively correlated with malaria parasitic load (r = -0.095, P<0.001). Intestinal parasite and/or malaria co-infection is a health problem among pregnant women living around Gilgel Gibe dam area. Therefore, intervention including improving sanitation, removing stagnant water, and health education to the pregnant women should be given.

  6. Prevalence Soil Transmitted Helminthiasis and malaria co-infection among pregnant women and risk factors in Gilgel Gibe dam Area, Southwest Ethiopia

    PubMed Central

    2013-01-01

    Background Malaria and Soil Transmitted Helminthiasis (STH) are co-endemic and major public health problems in Ethiopia. The aim of the study was to assess the prevalence of malaria and STHs co-infection and to determine the association risk factors. Methods A cross-sectional community based study was conducted on 388 pregnant women living in three districts around Gilgel Gibe Dam area, southwestern Ethiopia. Socio-demographic and socio-economic data, single stool sample and blood sample were collected from each participant. Results The prevalence of STH and malaria was 159 (41%) and 45 (11.6%), respectively and the prevalence of STHs/malaria co-infection was 30 (7.7%). Hookworm was the most prevalent 114 (29.4%) soil transmitted helminthiasis infection followed by Ascaris lumbricoides (A. lumbricoides) 58 (15%) and Trichuris trichiura (T. trichiura) 13 (3.4%). Habit of eating soil (Adjusted Odds Ratio (AOR) = 4.64, 95% CI: 1.50-14.36, P=0.008), presence of stagnant water near study participants’ house (AOR=2.99, 95% CI: 1.28-6.99, P=0.012) and habit of using human feces as a fertilizer (AOR= 5.34, 95% CI: 1.99-14.28, P<0.001) were found to be significantly associated with malaria and STH co-infection among the pregnant women. Hookworm parasitic load was positively correlated with malaria parasitic load (r = 0.299, P<0.001) while A. lumbricoides parasitic load was negatively correlated with malaria parasitic load (r = −0.095, P<0.001). Conclusion Intestinal parasite and/or malaria co-infection is a health problem among pregnant women living around Gilgel Gibe dam area. Therefore, intervention including improving sanitation, removing stagnant water, and health education to the pregnant women should be given. PMID:23837685

  7. Ranking Profiles

    ERIC Educational Resources Information Center

    Van Der Werf, Martin

    2007-01-01

    This article presents the "U.S. News" ranking profiles of four colleges, namely: (1) Smith College; (2) Washington University in St. Louis; (3) Colorado State University at Fort Collins; and (4) Whitman College. Smith College was in the top 10 of the nation's liberal-arts colleges, or just outside it, almost since the "U.S.…

  8. Predicting changing malaria risk after expanded insecticide-treated net coverage in Africa.

    PubMed

    Smith, David L; Hay, Simon I; Noor, Abdisalan M; Snow, Robert W

    2009-11-01

    The Roll Back Malaria (RBM) partnership has established goals for protecting vulnerable populations with locally appropriate vector control. In many places, these goals will be achieved by the mass distribution of insecticide treated bednets (ITNs). Mathematical models can forecast an ITN-driven realignment of malaria endemicity, defined by the Plasmodium falciparum parasite rate (PfPR) in children, to predict PfPR endpoints and appropriate program timelines for this change in Africa. The relative ease of measuring PfPR and its widespread use make it particularly suitable for monitoring and evaluation. This theory provides a method for context-dependent evaluation of ITN programs and a basis for setting rational ITN coverage targets over the next decade.

  9. Predicting changing malaria risk after expanded insecticide-treated net coverage in Africa

    PubMed Central

    Smith, David L.; Hay, Simon I.; Noor, Abdisalan M.; Snow, Robert W.

    2009-01-01

    The Roll Back Malaria (RBM) partnership has established goals for protecting vulnerable populations with locally appropriate vector control. In many places, these goals will be achieved by the mass distribution of insecticide treated bednets (ITNs). Mathematical models can forecast an ITN-driven realignment of malaria endemicity, defined by the Plasmodium falciparum parasite rate (PfPR) in children, to predict PfPR endpoints and appropriate program timelines for this change in Africa. The relative ease of measuring PfPR and its widespread use make it particularly suitable for monitoring and evaluation. This theory provides a method for context-dependent evaluation of ITN programs and a basis for setting rational ITN coverage targets over the next decade. PMID:19744887

  10. Malaria: prevention in travellers

    PubMed Central

    Croft, Ashley

    2000-01-01

    Definition Malaria is caused by a protozoan infection of red blood cells with one of four species of the genus plasmodium: P falciparum, P vivax, P ovale, or P malariae.1 Clinically, malaria may present in different ways, but it is usually characterised by fever (which may be swinging), tachycardia, rigors, and sweating. Anaemia, hepatosplenomegaly, cerebral involvement, renal failure, and shock may occur. Incidence/prevalence Each year there are 300-500 million clinical cases of malaria. About 40% of the world's population is at risk of acquiring the disease.23 Each year 25-30 million people from non-tropical countries visit areas in which malaria is endemic,4 of whom between 10 000 and 30 000 contract malaria.5 Aetiology/risk factors Malaria is mainly a rural disease, requiring standing water nearby. It is transmitted by bites6 from infected female anopheline mosquitoes,7 mainly at dusk and during the night.18 In cities, mosquito bites are usually from female culicene mosquitoes, which are not vectors of malaria.9 Malaria is resurgent in most tropical countries and the risk to travellers is increasing.10 Prognosis Ninety per cent of travellers who contract malaria do not become ill until after they return home.5 “Imported malaria” is easily treated if diagnosed promptly, and it follows a serious course in only about 12% of people.1112 The most severe form of the disease is cerebral malaria, with a case fatality rate in adult travellers of 2-6%,3 mainly because of delays in diagnosis.5 Aims To reduce the risk of infection; to prevent illness and death. Outcomes Rates of malarial illness and death, and adverse effects of treatment. Proxy measures include number of mosquito bites and number of mosquitoes in indoor areas. We found limited evidence linking number of mosquito bites and risk of malaria.13 Methods Clinical Evidence search and appraisal in November 1999. We reviewed all identified systematic reviews and randomised controlled trials (RCTs

  11. Helminth Infection and Eosinophilia and the Risk of Plasmodium falciparum Malaria in 1- to 6-Year-Old Children in a Malaria Endemic Area

    PubMed Central

    Bejon, Philip; Mwangi, Tabitha W.; Lowe, Brett; Peshu, Norbert; Hill, Adrian V. S.; Marsh, Kevin

    2008-01-01

    Background Helminth infection is common in malaria endemic areas, and an interaction between the two would be of considerable public health importance. Animal models suggest that helminth infections may increase susceptibility to malaria, but epidemiological data has been limited and contradictory. Methodology/Principal Findings In a vaccine trial, we studied 387 one- to six-year-old children for the effect of helminth infections on febrile Plasmodium falciparum malaria episodes. Gastrointestinal helminth infection and eosinophilia were prevalent (25% and 50% respectively), but did not influence susceptibility to malaria. Hazard ratios were 1 for gastrointestinal helminth infection (95% CI 0.6–1.6) and 0.85 and 0.85 for mild and marked eosinophilia, respectively (95% CI 0.56–1.76 and 0.69–1.96). Incident rate ratios for multiple episodes were 0.83 for gastro-intestinal helminth infection (95% CI 0.5–1.33) and 0.86 and 0.98 for mild and marked eosinophilia (95% CI 0.5–1.4 and 0.6–1.5). Conclusions/Significance There was no evidence that infection with gastrointestinal helminths or urinary schistosomiasis increased susceptibility to Plasmodium falciparum malaria in this study. Larger studies including populations with a greater prevalence of helminth infection should be undertaken. PMID:18265875

  12. Polymorphisms in host genes encoding NOSII, C-reactive protein, and adhesion molecules thrombospondin and E-selectin are risk factors for Plasmodium falciparum malaria in India.

    PubMed

    Kanchan, K; Pati, S S; Mohanty, S; Mishra, S K; Sharma, S K; Awasthi, S; Venkatesh, V; Habib, S

    2015-10-01

    Cytoadherence of Plasmodium falciparum-infected red blood cells (RBCs) in host microvasculature and complex regulation of the immune response are important contributors to the clinical outcome of disease. We tested the association of 23 single nucleotide polymorphisms (SNPs) and a microsatellite repeat in adhesion molecule genes THBS1 and ESEL, and immune regulatory molecule genes NOSII, CRP, and MBL2 with falciparum malaria in populations residing in a malaria-endemic and a non-endemic region of India. The THBS1 haplotype CCCCA (rs1478604, rs7170682, rs2664141, rs12912082, rs3743125) was a risk factor in the endemic region (relative risk = 3.78) and an ESEL SNP (rs5368, His468Tyr) associated with cerebral malaria (CM) [CM vs. non-cerebral malaria (NCM), odds ratio (OR) = 2.23, p = 0.03]. In the non-endemic region, an ESEL 3'UTR SNP (rs5359) associated with enhanced risk of disease (OR = 3.62, p = 1 × 10(-4)) and the CT genotype of the CRP promoter SNP (C/T/A) strongly associated with protection (severe vs. control, OR = 0.29, p = 6 × 10(-5)). Long repeat alleles of the NOSII promoter microsatellite (CCTTT)n exhibited strong association with protection and the NOSII ATG haplotype (rs3729508, rs2297520, rs9282801) was strongly protective against severe malaria in both regions (endemic, severe vs. control, OR = 0.05, p = 0.0001; non-endemic, severe vs. control, OR = 0.3, p = 1 × 10(-5)). Our results suggest differential contribution of variants of the investigated genes in determining the outcome of malaria in Indian populations.

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

    PubMed Central

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

    2014-01-01

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

  14. Randomized, Double-Blind, Placebo-Controlled Trial of Monthly versus Bimonthly Dihydroartemisinin-Piperaquine Chemoprevention in Adults at High Risk of Malaria

    PubMed Central

    Lwin, Khin Maung; Phyo, Aung Pyae; Tarning, Joel; Hanpithakpong, Warunee; Ashley, Elizabeth A.; Lee, Sue J.; Cheah, Phaikyeong; Singhasivanon, Pratap; White, Nicholas J.; Lindegårdh, Niklas

    2012-01-01

    Intermittent preventive treatment (IPT) is increasingly used to reduce malaria morbidity and mortality in children and pregnant women. The efficacy of IPT depends on the pharmacokinetic and pharmacodynamic properties of the antimalarial drugs used. Healthy adult male volunteers whose occupation put them at high risk of malaria on the Northwest border of Thailand were randomized to receive a 3-day-treatment dose of dihydroartemisinin-piperaquine monthly (DPm) or every 2 months (DPalt) or an identical placebo with or without fat (6.4g/dose) over a 9-month period. All volunteers were monitored weekly. One thousand adults were recruited. Dihydroartemisinin-piperaquine was well tolerated. There were 114 episodes of malaria (49 Plasmodium falciparum, 63 P. vivax, and 2 P. ovale). The protective efficacy against all malaria at 36 weeks was 98% (95% confidence interval [CI], 96% to 99%) in the DPm group and 86% (95% CI, 81% to 90%) in the DPalt group (for both, P < 0.0001 compared to the placebo group). As a result, the placebo group also had lower hematocrits during the study (P < 0.0001). Trough plasma piperaquine concentrations were the main determinant of efficacy; no malaria occurred in participants with a trough concentration above 31 ng/ml. Neither plasma piperaquine concentration nor efficacy was influenced by the coadministration of fat. DPm is safe to use and is effective in the prevention of malaria in adult males living in an area where P. vivax and multidrug-resistant P. falciparum malaria are endemic. PMID:22252804

  15. Risk of Plasmodium vivax malaria reintroduction in Uzbekistan: genetic characterization of parasites and status of potential malaria vectors in the Surkhandarya region.

    PubMed

    Severini, Carlo; Menegon, Michela; Di Luca, Marco; Abdullaev, Iso; Majori, Giancarlo; Razakov, Shavkat A; Gradoni, Luigi

    2004-10-01

    Plasmodium vivax malaria was eradicated from Uzbekistan in 1961. Due to resurgence of the disease in neighbouring states and massive population migration, there has been an increase of P. vivax malaria, imported from Tajikistan, resulting in a number of indigenous cases being identified in areas bordering that country. A molecular study using the merozoite surface protein 1 (msp-1) gene as a marker was performed on 24 P. vivax genomic isolates from 12 indigenous and 10 imported malaria cases that occurred in the Surkhandarya region during the summer of 2002. Results have shown a significant difference in the frequency of msp-1 types between indigenous and imported isolates, the latter showing greater genetic heterogeneity. An entomological investigation in the area suggested that three Anopheles species, namely A. superpictus, A. pulcherrimus and A. hyrcanus may have a potential role in the endemic transmission of P. vivax.

  16. An analysis of timing and frequency of malaria infection during pregnancy in relation to the risk of low birth weight, anaemia and perinatal mortality in Burkina Faso

    PubMed Central

    2012-01-01

    Background A prospective study aiming at assessing the effect of adding a third dose sulphadoxine-pyrimethamine (SP) to the standard two-dose intermittent preventive treatment for pregnant women was carried out in Hounde, Burkina Faso, between March 2006 and July 2008. Pregnant women were identified as earlier as possible during pregnancy through a network of home visitors, referred to the health facilities for inclusion and followed up until delivery. Methods Study participants were enrolled at antenatal care (ANC) visits and randomized to receive either two or three doses of SP at the appropriate time. Women were visited daily and a blood slide was collected when there was fever (body temperature > 37.5°C) or history of fever. Women were encouraged to attend ANC and deliver in the health centre, where the new-born was examined and weighed. The timing and frequency of malaria infection was analysed in relation to the risk of low birth weight, maternal anaemia and perinatal mortality. Results Data on birth weight and haemoglobin were available for 1,034 women. The incidence of malaria infections was significantly lower in women having received three instead of two doses of SP. Occurrence of first malaria infection during the first or second trimester was associated with a higher risk of low birth weight: incidence rate ratios of 3.56 (p < 0.001) and 1.72 (p = 0.034), respectively. After adjusting for possible confounding factors, the risk remained significantly higher for the infection in the first trimester of pregnancy (adjusted incidence rate ratio = 2.07, p = 0.002). The risk of maternal anaemia and perinatal mortality was not associated with the timing of first malaria infection. Conclusion Malaria infection during first trimester of pregnancy is associated to a higher risk of low birth weight. Women should be encouraged to use long-lasting insecticidal nets before and throughout their pregnancy. PMID:22433778

  17. An analysis of timing and frequency of malaria infection during pregnancy in relation to the risk of low birth weight, anaemia and perinatal mortality in Burkina Faso.

    PubMed

    Valea, Innocent; Tinto, Halidou; Drabo, Maxime K; Huybregts, Lieven; Sorgho, Hermann; Ouedraogo, Jean-Bosco; Guiguemde, Robert T; van Geertruyden, Jean Pierre; Kolsteren, Patrick; D'Alessandro, Umberto

    2012-03-16

    A prospective study aiming at assessing the effect of adding a third dose sulphadoxine-pyrimethamine (SP) to the standard two-dose intermittent preventive treatment for pregnant women was carried out in Hounde, Burkina Faso, between March 2006 and July 2008. Pregnant women were identified as earlier as possible during pregnancy through a network of home visitors, referred to the health facilities for inclusion and followed up until delivery. Study participants were enrolled at antenatal care (ANC) visits and randomized to receive either two or three doses of SP at the appropriate time. Women were visited daily and a blood slide was collected when there was fever (body temperature > 37.5°C) or history of fever. Women were encouraged to attend ANC and deliver in the health centre, where the new-born was examined and weighed. The timing and frequency of malaria infection was analysed in relation to the risk of low birth weight, maternal anaemia and perinatal mortality. Data on birth weight and haemoglobin were available for 1,034 women. The incidence of malaria infections was significantly lower in women having received three instead of two doses of SP. Occurrence of first malaria infection during the first or second trimester was associated with a higher risk of low birth weight: incidence rate ratios of 3.56 (p < 0.001) and 1.72 (p = 0.034), respectively. After adjusting for possible confounding factors, the risk remained significantly higher for the infection in the first trimester of pregnancy (adjusted incidence rate ratio = 2.07, p = 0.002). The risk of maternal anaemia and perinatal mortality was not associated with the timing of first malaria infection. Malaria infection during first trimester of pregnancy is associated to a higher risk of low birth weight. Women should be encouraged to use long-lasting insecticidal nets before and throughout their pregnancy.

  18. The influence of the Gilgel-Gibe hydroelectric dam in Ethiopia on caregivers' knowledge, perceptions and health-seeking behaviour towards childhood malaria

    PubMed Central

    2010-01-01

    Background Malaria remains the most important public health problem in tropical and subtropical areas. Mothers' or caregivers' ability to recognize childhood malaria-related morbidity is crucial as knowledge, attitudes and health seeking behavior of caregivers towards childhood malaria could influence response to signs of the disease. Methods A total of 1,003 caregivers in 'at-risk' villages in close proximity to the Gilgel-Gibe hydroelectric dam in south-western Ethiopia, and 953 caregivers in 'control' villages further away from the dam were surveyed using structured questionnaires to assess their knowledge, perceptions and health seeking behaviour about childhood malaria. Results Malaria (busa) was ranked as the most serious health problem. Caregivers perceived childhood malaria as a preventable ('at-risk' 96%, 'control' 86%) and treatable ('at-risk' 98% and 'control' 96%) disease. Most caregivers correctly associated the typical clinical manifestations with malaria attacks. The use of insecticide-treated nets (ITNs) was mentioned as a personal protective measure, whereas the role of indoor residual spraying (IRS) in malaria prevention and control was under-recognized. Most of the caregivers would prefer to seek treatment in health-care services in the event of malaria and reported the use of recommended anti-malarials. Conclusion Health education to improve knowledge, perceptions and health-seeking behaviour related to malaria is equally important for caregivers in 'at risk' villages and caregivers in 'control' villages as minimal differences seen between both groups. Concluding, there may be a need of more than one generation after the introduction of the dam before differences can be noticed. Secondly, differences in prevalence between 'control' and 'at-risk' villages may not be sufficient to influence knowledge and behaviour. PMID:20146830

  19. The influence of the Gilgel-Gibe hydroelectric dam in Ethiopia on caregivers' knowledge, perceptions and health-seeking behaviour towards childhood malaria.

    PubMed

    Yewhalaw, Delenasaw; Kassahun, Wondwossen; Woldemichael, Kifle; Tushune, Kora; Sudaker, Morankar; Kaba, Daniel; Duchateau, Luc; Van Bortel, Wim; Speybroeck, Niko

    2010-02-11

    Malaria remains the most important public health problem in tropical and subtropical areas. Mothers' or caregivers' ability to recognize childhood malaria-related morbidity is crucial as knowledge, attitudes and health seeking behavior of caregivers towards childhood malaria could influence response to signs of the disease. A total of 1,003 caregivers in 'at-risk' villages in close proximity to the Gilgel-Gibe hydroelectric dam in south-western Ethiopia, and 953 caregivers in 'control' villages further away from the dam were surveyed using structured questionnaires to assess their knowledge, perceptions and health seeking behaviour about childhood malaria. Malaria (busa) was ranked as the most serious health problem. Caregivers perceived childhood malaria as a preventable ('at-risk' 96%, 'control' 86%) and treatable ('at-risk' 98% and 'control' 96%) disease. Most caregivers correctly associated the typical clinical manifestations with malaria attacks. The use of insecticide-treated nets (ITNs) was mentioned as a personal protective measure, whereas the role of indoor residual spraying (IRS) in malaria prevention and control was under-recognized. Most of the caregivers would prefer to seek treatment in health-care services in the event of malaria and reported the use of recommended anti-malarials. Health education to improve knowledge, perceptions and health-seeking behaviour related to malaria is equally important for caregivers in 'at risk' villages and caregivers in 'control' villages as minimal differences seen between both groups. Concluding, there may be a need of more than one generation after the introduction of the dam before differences can be noticed. Secondly, differences in prevalence between 'control' and 'at-risk' villages may not be sufficient to influence knowledge and behaviour.

  20. High Prevalence of Malaria in Zambezia, Mozambique: The Protective Effect of IRS versus Increased Risks Due to Pig-Keeping and House Construction

    PubMed Central

    Temu, Emmanuel A.; Coleman, Mike; Abilio, Ana Paula; Kleinschmidt, Immo

    2012-01-01

    Background African countries are scaling up malaria interventions, especially insecticide treated nets (ITN) and indoor residual spraying (IRS), for which ambitious coverage targets have been set. In spite of these efforts infection prevalence remains high in many parts of the continent. This study investigated risk factors for malaria infection in children using three malaria indicator surveys from Zambezia province, Mozambique. The impact of IRS and ITNs, the effects of keeping farm animals and of the construction material of roofs of houses and other potential risk factors associated with malaria infection in children were assessed. Methods Cross-sectional community-based surveys were conducted in October of 2006, 2007 and 2008. A total of 8338 children (ages 1–15 years) from 2748 households were included in the study. All children were screened for malaria by rapid diagnostic tests. Caregiver interviews were used to assess household demographic and wealth characteristics and ITN and IRS coverage. Associations between malaria infection, vector control interventions and potential risk factors were assessed. Results Overall, the prevalence of malaria infection was 47.8% (95%CI: 38.7%–57.1%) in children 1–15 years of age, less than a quarter of children (23.1%, 95%CI: 19.1%–27.6%) were sleeping under ITN and almost two thirds were living in IRS treated houses (coverage 65.4%, 95%CI: 51.5%–77.0%). Protective factors that were independently associated with malaria infection were: sleeping in an IRS house without sleeping under ITN (Odds Ratio (OR)  = 0.6; 95%CI: 0.4–0.9); additional protection due to sleeping under ITN in an IRS treated house (OR = 0.5; 95%CI: 0.3–0.7) versus sleeping in an unsprayed house without a ITN; and parental education (primary/secondary: OR = 0.6; 95%CI: 0.5–0.7) versus parents with no education. Increased risk of infection was associated with: current fever (OR = 1.2; 95%CI: 1.0–1.5) versus no fever; pig

  1. Investigating the Contribution of Peri-domestic Transmission to Risk of Zoonotic Malaria Infection in Humans

    PubMed Central

    Manin, Benny O.; Ferguson, Heather M.; Vythilingam, Indra; Fornace, Kim; William, Timothy; Torr, Steve J.; Drakeley, Chris; Chua, Tock H.

    2016-01-01

    Background In recent years, the primate malaria Plasmodium knowlesi has emerged in human populations throughout South East Asia, with the largest hotspot being in Sabah, Malaysian Borneo. Control efforts are hindered by limited knowledge of where and when people get exposed to mosquito vectors. It is assumed that exposure occurs primarily when people are working in forest areas, but the role of other potential exposure routes (including domestic or peri-domestic transmission) has not been thoroughly investigated. Methodology/Principal Findings We integrated entomological surveillance within a comprehensive case-control study occurring within a large hotspot of transmission in Sabah, Malaysia. Mosquitoes were collected at 28 pairs households composed of one where an occupant had a confirmed P. knowlesi infection within the preceding 3 weeks (“case”) and an associated “control” where no infection was reported. Human landing catches were conducted to measure the number and diversity of mosquitoes host seeking inside houses and in the surrounding peri-domestic (outdoors but around the household) areas. The predominant malaria vector species was Anopheles balabacensis, most of which were caught outdoors in the early evening (6pm - 9pm). It was significantly more abundant in the peri-domestic area than inside houses (5.5-fold), and also higher at case than control households (0.28±0.194 vs 0.17±0.127, p<0.001). Ten out of 641 An. balabacensis tested were positive for simian malaria parasites, but none for P. knowlesi. Conclusions/Significance This study shows there is a possibility that humans can be exposed to P. knowlesi infection around their homes. The vector is highly exophagic and few were caught indoors indicating interventions using bednets inside households may have relatively little impact. PMID:27741235

  2. Cerebral malaria

    PubMed Central

    Rénia, Laurent; Wu Howland, Shanshan; Claser, Carla; Charlotte Gruner, Anne; Suwanarusk, Rossarin; Hui Teo, Teck; Russell, Bruce; Ng, Lisa

    2012-01-01

    Cerebral malaria is the most severe pathology caused by the malaria parasite, Plasmodium falciparum. The pathogenic mechanisms leading to cerebral malaria are still poorly defined as studies have been hampered by limited accessibility to human tissues. Nevertheless, histopathology of post-mortem human tissues and mouse models of cerebral malaria have indicated involvement of the blood-brain barrier in cerebral malaria. In contrast to viruses and bacteria, malaria parasites do not infiltrate and infect the brain parenchyma. Instead, rupture of the blood-brain barrier occurs and may lead to hemorrhages resulting in neurological alterations. Here, we review the most recent findings from human studies and mouse models on the interactions of malaria parasites and the blood-brain barrier, shedding light on the pathogenesis of cerebral malaria, which may provide directions for possible interventions. PMID:22460644

  3. International Air Travel to Ohio, USA, and the Impact on Malaria, Influenza, and Hepatitis A

    PubMed Central

    Brannen, Donald E.; Alhammad, Ali; Branum, Melissa; Schmitt, Amy

    2016-01-01

    The State of Ohio led the United States in measles in 2014, ostensibly related to international air travel (IAT), and ranked lower than 43 other states in infectious disease outbreak preparedness. We conducted a retrospective cohort study using surveillance data of the total Ohio population of 11 million from 2010 through 2014 with a nested case control of air travelers to determine the risk of malaria, seasonal influenza hospitalizations (IH), and hepatitis A (HA) disease related to international travel and to estimate the association with domestic enplanement. IAT appeared protective for HA and IH with a risk of 0.031 (.02–.04) but for malaria was 2.7 (2.07–3.62). Enplanement increased the risk for nonendemic M 3.5 (2.5–4.9) and for HA and IH 1.39 (1.34–1.44). IAT's ratio of relative risk (RRR) of malaria to HA and IH was 87.1 (55.8–136) greater than 219 times versus domestic enplanement which was protective for malaria at 0.397 (0.282–0.559). Malaria is correlated with IAT with cases increasing by 6.9 for every 10,000 passports issued. PMID:27123365

  4. International Air Travel to Ohio, USA, and the Impact on Malaria, Influenza, and Hepatitis A.

    PubMed

    Brannen, Donald E; Alhammad, Ali; Branum, Melissa; Schmitt, Amy

    2016-01-01

    The State of Ohio led the United States in measles in 2014, ostensibly related to international air travel (IAT), and ranked lower than 43 other states in infectious disease outbreak preparedness. We conducted a retrospective cohort study using surveillance data of the total Ohio population of 11 million from 2010 through 2014 with a nested case control of air travelers to determine the risk of malaria, seasonal influenza hospitalizations (IH), and hepatitis A (HA) disease related to international travel and to estimate the association with domestic enplanement. IAT appeared protective for HA and IH with a risk of 0.031 (.02-.04) but for malaria was 2.7 (2.07-3.62). Enplanement increased the risk for nonendemic M 3.5 (2.5-4.9) and for HA and IH 1.39 (1.34-1.44). IAT's ratio of relative risk (RRR) of malaria to HA and IH was 87.1 (55.8-136) greater than 219 times versus domestic enplanement which was protective for malaria at 0.397 (0.282-0.559). Malaria is correlated with IAT with cases increasing by 6.9 for every 10,000 passports issued.

  5. Dosage of Sulfadoxine-Pyrimethamine and Risk of Low Birth Weight in a Cohort of Zambian Pregnant Women in a Low Malaria Prevalence Region.

    PubMed

    Stoner, Marie C D; Vwalika, Bellington; Smid, Marcela; Kumwenda, Andrew; Stringer, Elizabeth; Chi, Benjamin H; Stringer, Jeff S A

    2017-01-11

    In Lusaka, Zambia, where malaria prevalence is low, national guidelines continue to recommend that all pregnant women receive sulfadoxine-pyrimethamine (SP) for malaria prophylaxis monthly at every scheduled antenatal care visit after 16 weeks of gestation. Human immunodeficiency virus (HIV)-positive women should receive co-trimoxazole prophylaxis for HIV and not SP, but many still receive SP. We sought to determine whether increased dosage of SP is still associated with a reduced risk of low birth weight (LBW) in an area where malaria transmission is low. Our secondary objective was to determine whether any association between SP and LBW is modified by receipt of antiretroviral therapy (ART). We analyzed data routinely collected from a cohort of HIV-positive pregnant women with singleton births in Lusaka, Zambia, between February 2006 and December 2012. We used a log-Poisson model to estimate the risk of LBW by dosage of SP and to determine whether the association between SP and LBW varied by receipt of ART. Risk of LBW declined as the number of doses increased and appeared lowest among women who received three doses (adjusted risk ratio [ARR] = 0.78; 95% confidence interval [CI] = 0.64-0.95). In addition, women receiving combination ART had a higher risk of delivering an LBW infant compared with women receiving no treatment or prophylaxis (ARR = 1.18; 95% CI = 1.09-1.28), but this risk was attenuated among women who were receiving SP (risk ratio = 1.09; 95% CI = 0.99-1.21). SP was associated with a reduced risk of LBW in HIV-positive women, including those receiving ART, in a low malaria prevalence region. © The American Society of Tropical Medicine and Hygiene.

  6. Severity of imported malaria: protective effect of taking malaria chemoprophylaxis

    PubMed Central

    2013-01-01

    Background Although chemoprophylaxis remains an important strategy for preventing malaria in travellers, its effectiveness may be compromised by lack of adherence. Inappropriate use of chemoprophylaxis is likely to increase the risk of acquiring malaria, but may probably also worsen the severity of imported cases. The aim of this study was to assess the impact of use of malaria chemoprophylaxis on clinical features and outcome of imported malaria. Methods Demographic, clinical and laboratory data of patients included in the Rotterdam Malaria Cohort between 1998 and 2011 were systematically collected and analysed. Patients were classified as self-reported compliant or non-compliant users or as non-users of chemoprophylaxis. Severe malaria was defined using the 2010 WHO criteria. Results Details on chemoprophylaxis were available for 559 of the 604 patients, of which 64.6% were non-users, 17.9% were inadequate users and 17.5% reported to be adequate users. The group of non-users was predominated by patients with African ethnicity, partial immunity and people visiting friends and relatives. The majority contracted Plasmodium falciparum malaria. In contrast, compliant users acquired non-falciparum malaria more frequently, had significant lower P. falciparum loads on admission, shorter duration of hospitalization and significant lower odds for severe malaria as compared with non-users. Patients with P. falciparum malaria were more likely to have taken their chemoprophylaxis less compliantly than those infected with non-P. falciparum species. Multivariate analysis showed that self-reported adequate prophylaxis and being a partially immune traveller visiting friends and relatives was associated with significantly lower odds ratio of severe malaria. In contrast, age, acquisition of malaria in West-Africa and being a non-immune tourist increased their risk significantly. Conclusions Compliant use of malaria chemoprophylaxis was associated with significantly lower odds

  7. [Malaria in Algerian Sahara].

    PubMed

    Hammadi, D; Boubidi, S C; Chaib, S E; Saber, A; Khechache, Y; Gasmi, M; Harrat, Z

    2009-08-01

    Thanks to the malaria eradication campaign launched in Algeria in 1968, the number of malaria cases fell down significantly from 95,424 cases in 1960 to 30 cases in 1978. At that time the northern part of the country was declared free of Plasmodium falciparum. Only few cases belonging to P. vivax persisted in residual foci in the middle part of the country. In the beginning of the eighties, the south of the country was marked by an increase of imported malaria cases. The resurgence of the disease in the oases coincided with the opening of the Trans-Saharan road and the booming trade with the neighbouring southern countries. Several authors insisted on the risk of introduction of malaria or its exotic potential vectors in Algeria via this new road. Now, the totality of malaria autochthonous cases in Algeria are located in the south of the country where 300 cases were declared during the period (1980-2007). The recent outbreak recorded in 2007 at the borders with Mall and the introduction of Anopheles gambiae into the Algerian territory show the vulnerability of this area to malaria which is probably emphasized by the local environmental changes. The authors assess the evolution of malaria in the Sahara region and draw up the distribution of the anopheles in this area.

  8. Dehydration and malaria augment the risk of developing chronic kidney disease in Sri Lanka

    PubMed Central

    Siriwardhana, E. A. R. I. E.; Perera, P. A. J.; Sivakanesan, R.; Abeysekara, T.; Nugegoda, D. B.; Jayaweera, J. A. A. S.

    2015-01-01

    Chronic kidney disease (CKD) of unknown etiology (CKDu) is a serious health issue in Sri Lanka. One-to-one age and sex-matched two sample comparative study was carried out in the Medawachchiya divisional secretariat area of the North Central Province (NCP) of Sri Lanka, by randomly selecting 100 CKDu patients and 100 age and sex-matched subjects from non-CKDu affected families from the same area. An interviewer-administered questionnaire was used for the collection of data pertaining to occupation, medical history and lifestyle. Data were analyzed using a conditional linear logistic model. Working for >6 h in the field per day, exposure to sun, drinking water only from well, consumption of <3 L of water per day, and having a history of malaria were found to be having significant (P < 0.05) likelihood toward the development of CKDu. Treatment of water prior to consumption had a significant protective effect against CKDu. Dehydration, history of malaria and drinking untreated well water from are likely contribute to the development of CKD of unknown etiology among the inhabitants of NCP, Sri Lanka. PMID:26060363

  9. Dehydration and malaria augment the risk of developing chronic kidney disease in Sri Lanka.

    PubMed

    Siriwardhana, E A R I E; Perera, P A J; Sivakanesan, R; Abeysekara, T; Nugegoda, D B; Jayaweera, J A A S

    2015-01-01

    Chronic kidney disease (CKD) of unknown etiology (CKDu) is a serious health issue in Sri Lanka. One-to-one age and sex-matched two sample comparative study was carried out in the Medawachchiya divisional secretariat area of the North Central Province (NCP) of Sri Lanka, by randomly selecting 100 CKDu patients and 100 age and sex-matched subjects from non-CKDu affected families from the same area. An interviewer-administered questionnaire was used for the collection of data pertaining to occupation, medical history and lifestyle. Data were analyzed using a conditional linear logistic model. Working for >6 h in the field per day, exposure to sun, drinking water only from well, consumption of <3 L of water per day, and having a history of malaria were found to be having significant (P < 0.05) likelihood toward the development of CKDu. Treatment of water prior to consumption had a significant protective effect against CKDu. Dehydration, history of malaria and drinking untreated well water from are likely contribute to the development of CKD of unknown etiology among the inhabitants of NCP, Sri Lanka.

  10. Is staying overnight in a farming hut a risk factor for malaria infection in a setting with insecticide-treated bed nets in rural Laos?

    PubMed Central

    2010-01-01

    Background Overnight stays in farming huts are known to pose a risk of malaria infection. However, studies reporting the risk were conducted in the settings of poor net coverage. This study sought to assess whether an overnight stay in a farming hut is associated with an increased risk of malaria infection if insecticide-treated bed nets (ITNs) are properly used. Methods A pair of cross-sectional surveys was carried out in the Lamarm district of Sekong province, Laos, in March (dry season) and August (rainy season) in 2008. Questionnaire-based interviews and blood examinations were conducted with farmers and their household members from three randomly selected villages in March (127 households, 891 people) and August (128 households, 919 people). Logistic regression analysis, adjusted for potential confounding factors, was used to assess the association between malaria infection status and frequency of overnight stays for the two weeks prior to the study in both the seasons. Results In March, 13.7% of participants reported staying overnight in a farming hut at least once in the previous two weeks. The percentage increased to 74.6% in August. Not only adults but also young children stayed overnight as often as adults. The use of an ITN the preceding night was common both in farming huts (66.3% in March, 95.2% in August), and in main residences (85.8% in March, 92.5% in August). Logistic regression analysis showed no statistical association between malaria infection status and frequency of overnight stays in farming huts in either study period. However, people sharing one family type net with five people or more were significantly more likely to have malaria than those sharing a net with up to two people in the dry season. Conclusions This study showed that staying overnight in farming huts was not associated with an increased risk of malaria infection in the setting where ITNs were widely used in farming huts. It suggests that malaria infection during overnight

  11. High Plasmodium falciparum longitudinal prevalence is associated with high multiclonality and reduced clinical malaria risk in a seasonal transmission area of Mali.

    PubMed

    Adomako-Ankomah, Yaw; Chenoweth, Matthew S; Durfee, Katelyn; Doumbia, Saibou; Konate, Drissa; Doumbouya, Mory; Keita, Abdoul S; Nikolaeva, Daria; Tullo, Gregory S; Anderson, Jennifer M; Fairhurst, Rick M; Daniels, Rachel; Volkman, Sarah K; Diakite, Mahamadou; Miura, Kazutoyo; Long, Carole A

    2017-01-01

    The effects of persistent Plasmodium falciparum (Pf) infection and multiclonality on subsequent risk of clinical malaria have been reported, but the relationship between these 2 parameters and their relative impacts on the clinical outcome of infection are not understood. A longitudinal cohort study was conducted in a seasonal and high-transmission area of Mali, in which 500 subjects aged 1-65 years were followed for 1 year. Blood samples were collected every 2 weeks, and incident malaria cases were diagnosed and treated. Pf infection in each individual at each time point was assessed by species-specific nested-PCR, and Pf longitudinal prevalence per person (PfLP, proportion of Pf-positive samples over 1 year) was calculated. Multiclonality of Pf infection was measured using a 24-SNP DNA barcoding assay at 4 time-points (two in wet season, and two in dry season) over one year. PfLP was positively correlated with multiclonality at each time point (all r≥0.36; all P≤0.011). When host factors (e.g., age, gender), PfLP, and multiclonality (at the beginning of the transmission season) were analyzed together, only increasing age and high PfLP were associated with reduced clinical malaria occurrence or reduced number of malaria episodes (for both outcomes, P<0.001 for age, and P = 0.005 for PfLP). When age, PfLP and baseline Pf positivity were analyzed together, the effect of high PfLP remained significant even after adjusting for the other two factors (P = 0.001 for malaria occurrence and P<0.001 for number of episodes). In addition to host age and baseline Pf positivity, both of which have been reported as important modifiers of clinical malaria risk, our results demonstrate that persistent parasite carriage, but not baseline multiclonality, is associated with reduced risk of clinical disease in this population. Our study emphasizes the importance of considering repeated parasite exposure in future studies that evaluate clinical malaria risk.

  12. High Plasmodium falciparum longitudinal prevalence is associated with high multiclonality and reduced clinical malaria risk in a seasonal transmission area of Mali

    PubMed Central

    Adomako-Ankomah, Yaw; Chenoweth, Matthew S.; Durfee, Katelyn; Doumbia, Saibou; Konate, Drissa; Doumbouya, Mory; Keita, Abdoul S.; Nikolaeva, Daria; Tullo, Gregory S.; Anderson, Jennifer M.; Fairhurst, Rick M.; Daniels, Rachel; Volkman, Sarah K.; Diakite, Mahamadou; Long, Carole A.

    2017-01-01

    The effects of persistent Plasmodium falciparum (Pf) infection and multiclonality on subsequent risk of clinical malaria have been reported, but the relationship between these 2 parameters and their relative impacts on the clinical outcome of infection are not understood. A longitudinal cohort study was conducted in a seasonal and high-transmission area of Mali, in which 500 subjects aged 1–65 years were followed for 1 year. Blood samples were collected every 2 weeks, and incident malaria cases were diagnosed and treated. Pf infection in each individual at each time point was assessed by species-specific nested-PCR, and Pf longitudinal prevalence per person (PfLP, proportion of Pf-positive samples over 1 year) was calculated. Multiclonality of Pf infection was measured using a 24-SNP DNA barcoding assay at 4 time-points (two in wet season, and two in dry season) over one year. PfLP was positively correlated with multiclonality at each time point (all r≥0.36; all P≤0.011). When host factors (e.g., age, gender), PfLP, and multiclonality (at the beginning of the transmission season) were analyzed together, only increasing age and high PfLP were associated with reduced clinical malaria occurrence or reduced number of malaria episodes (for both outcomes, P<0.001 for age, and P = 0.005 for PfLP). When age, PfLP and baseline Pf positivity were analyzed together, the effect of high PfLP remained significant even after adjusting for the other two factors (P = 0.001 for malaria occurrence and P<0.001 for number of episodes). In addition to host age and baseline Pf positivity, both of which have been reported as important modifiers of clinical malaria risk, our results demonstrate that persistent parasite carriage, but not baseline multiclonality, is associated with reduced risk of clinical disease in this population. Our study emphasizes the importance of considering repeated parasite exposure in future studies that evaluate clinical malaria risk. PMID:28158202

  13. Measuring malaria endemicity from intense to interrupted transmission

    PubMed Central

    Hay, Simon I; Smith, David L; Snow, Robert W

    2008-01-01

    Summary The quantification of malaria transmission for the classification of malaria risk has long been a concern for epidemiologists. During the era of the Global Malaria Eradication Programme, measurements of malaria endemicity were institutionalised by their incorporation into rules outlining defined action points for malaria control programmes. We review the historical development of these indices and their contemporary relevance. This is at a time when many malaria-endemic countries are scaling-up their malaria control activities and reconsidering their prospects for elimination. These considerations are also important to an international community that has recently been challenged to revaluate the prospects for malaria eradication. PMID:18387849

  14. 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.

  15. Cytokine Profiles at Birth Predict Malaria Severity during Infancy

    PubMed Central

    Prevots, D. Rebecca; Morrison, Robert; Harrington, Whitney; Gwamaka, Moses; Kurtis, Jonathan D.; Fried, Michal; Duffy, Patrick E.

    2013-01-01

    Background Severe malaria risk varies between individuals, and most of this variation remains unexplained. Here, we examined the hypothesis that cytokine profiles at birth reflect inter-individual differences that persist and influence malaria parasite density and disease severity throughout early childhood. Methods and Findings Cytokine levels (TNF-α, IFN-γ, IL-1β, IL-4, IL-5, IL-6 and IL-10) were measured at birth (cord blood; N=783) and during subsequent routine follow-up visits (peripheral blood) for children enrolled between 2002 and 2006 into a birth cohort in Muheza, Tanzania. Children underwent blood smear and clinical assessments every 2-4 weeks, and at the time of any illness. Cord blood levels of all cytokines were positively correlated with each other (Spearman’s rank correlation). Cord levels of IL-1β and TNF-α (but not other cytokines) correlated with levels of the same cytokine measured at routine visits during early life (P < 0.05). Higher cord levels of IL-1β but not TNF-α were associated with lower parasite densities during infancy (P=0.003; Generalized Estimating Equation (GEE) method), with an average ~40% reduction versus children with low cord IL-1β levels, and with decreased risk of severe malaria during follow-up (Cox regression): adjusted hazard ratio (95% CI) 0.60 (0.39-0.92), P = 0.02. Conclusion IL-1β levels at birth are related to future IL-1β levels as well as the risk of severe malaria in early life. The effect on severe malaria risk may be due in part to the effect of inflammatory cytokines to control parasite density. PMID:24130857

  16. Mapping residual transmission for malaria elimination.

    PubMed

    Reiner, Robert C; Le Menach, Arnaud; Kunene, Simon; Ntshalintshali, Nyasatu; Hsiang, Michelle S; Perkins, T Alex; Greenhouse, Bryan; Tatem, Andrew J; Cohen, Justin M; Smith, David L

    2015-12-29

    Eliminating malaria from a defined region involves draining the endemic parasite reservoir and minimizing local malaria transmission around imported malaria infections . In the last phases of malaria elimination, as universal interventions reap diminishing marginal returns, national resources must become increasingly devoted to identifying where residual transmission is occurring. The needs for accurate measures of progress and practical advice about how to allocate scarce resources require new analytical methods to quantify fine-grained heterogeneity in malaria risk. Using routine national surveillance data from Swaziland (a sub-Saharan country on the verge of elimination), we estimated individual reproductive numbers. Fine-grained maps of reproductive numbers and local malaria importation rates were combined to show 'malariogenic potential', a first for malaria elimination. As countries approach elimination, these individual-based measures of transmission risk provide meaningful metrics for planning programmatic responses and prioritizing areas where interventions will contribute most to malaria elimination.

  17. Clinical, geographical, and temporal risk factors associated with presentation and outcome of vivax malaria imported into the United Kingdom over 27 years: observational study

    PubMed Central

    Broderick, Claire; Nadjm, Behzad; Smith, Valerie; Blaze, Marie; Checkley, Anna; Chiodini, Peter L

    2015-01-01

    Objective To examine temporal and geographical trends, risk factors, and seasonality of imported vivax malaria in the United Kingdom to inform clinical advice and policy. Design Observational study. Setting National surveillance data from the UK Public Health England Malaria Reference Laboratory, data from the International Passenger Survey, and international climactic data. Participants All confirmed and notified cases of malaria in the UK (n=50 187) from 1987 to 2013, focusing on 12 769 cases of vivax malaria. Main outcome measures Mortality, sociodemographic details (age, UK region, country of birth and residence, and purpose of travel), destination, and latency (time between arrival in the UK and onset of symptoms). Results Of the malaria cases notified, 25.4% (n=12 769) were due to Plasmodium vivax, of which 78.6% were imported from India and Pakistan. Most affected patients (53.5%) had travelled to visit friends and relatives, and 11.1% occurred in tourists. Imported P vivax is concentrated in areas with large communities of south Asian heritage. Overall mortality was 7/12 725 (0.05%), but with no deaths in 9927 patients aged under 50 years. Restricting the analysis to those aged more than 50 years, mortality was 7/2798 (0.25%), increasing to 4/526 (0.76%) (adjusted odds ratio 32.0, 95% confidence interval 7.1 to 144.0, P<0.001) in those aged 70 years or older. Annual notifications decreased sharply over the period, while traveller numbers between the UK and South Asia increased. The risk of acquiring P vivax from South Asia was year round but was twice as high from June to September (40 per 100 000 trips) compared with the rest of the year. There was strong seasonality in the latency from arrival in the UK to presentation, significantly longer in those arriving in the UK from South Asia from October to March (median 143 days) versus those arriving from April to September (37 days, P<0.001). Conclusions Travellers visiting friends and family in

  18. New guidelines on malaria prevention: A summary.

    PubMed

    Swales, Claire A; Chiodini, Peter L; Bannister, Barbara A

    2007-02-01

    Travellers to many tropical areas remain at risk of contracting malaria. Resistance of malaria parasites to a number of drugs continues to increase in degree and distribution, so that some older, trusted prophylactic drugs, such as chloroquine, are no longer useful in some parts of the world. Despite the introduction of new drugs and the reduction of malaria risk in some areas, such as parts of India, the number of people travelling continues to increase and malaria reports in the UK are not decreasing. New updated prevention guidelines from the Health Protection Agency Advisory Committee on Malaria Prevention (ACMP) in UK travellers (Chiodini P, Hill D, Lalloo D, Lea G, Walker E, Whitty C, et al. Guidelines for malaria prevention in travellers from the United Kingdom. London: Health Protection Agency; January 2007. Available from: http://www.hpa.org.uk/infections/topics_az/malaria/default.htm) aim to raise awareness of the risks of malaria and help UK travel health advisors in giving malaria prevention advice to all those who need it. Together with the ACMP malaria treatment guidelines it is hoped that the risk of illness and death from malaria in UK travellers can be reduced. This article summarises the new ACMP malaria prevention guidelines.

  19. [Airport malaria].

    PubMed

    Queyriaux, Benjamin; Pradines, Bruno; Hasseine, Lilia; Coste, Sébastien; Rodriguez, Patrick; Coffinet, Thierry; Haus-Cheymol, Rachel; Rogier, Christophe

    2009-01-01

    Airport malaria is a particular form of autochthonous malaria: it happens when the Plasmodium infected Anopheles genus mosquito travels from an endemic area to a malaria free airport. Since 1969, 30 cases of airport malaria have been reported in France, 2 during summer 2008. The severity of airport malaria is explained by the frequency of Plasmodium falciparum infecting non immune individuals and an often important diagnosis delay. It is a compulsory notification disease in France. The International Health Regulations (IHR) require states to check that airplanes coming from malaria or arboviral endemic area are systematically disinsected. Vector control measures have to be implemented within a distance of at least 400 meters around the perimeter of airports in malaria or arboviral endemic areas. In France, this measure applies to all airports of French overseas territories, except for the island of Saint-Pierre and Miquelon.

  20. Anopheles gambiae exploits the treehole ecosystem in western Kenya: a new urban malaria risk?

    PubMed

    Omlin, Francois X; Carlson, John C; Ogbunugafor, C Brandon; Hassanali, Ahmed

    2007-12-01

    At six sites in western Kenya, we explored the presence of Anopheles immature stages in treeholes. An. gambiae larvae were found in 19 species, 13 of which are exotic. The most common exotic species were Delonix regia, Jacaranda mimosipholia, and Eucalyptus citrodora. In Kisumu city, longitudinal assessments of 10 Flamboyant trees showed repeated presence of An. gambiae s.s. in treeholes with water. Production of Anopheles larvae did not correlate with habitat volume but with habitat height, showing a strong but statistically insignificant negative correlation. During a dry season, eggs recovered by rinsing dry treeholes hatched into 2.5 +/- 3.06 An. gambiae and 7.9 +/- 8.2 Aedes larvae. In cage experiments, An. gambiae s.s. laid more eggs in water originating from treeholes than in distilled or lake water, implying preference for ovipositing in this habitat. Our findings indicate that treeholes represent a hitherto unrecognized habitat for malaria vectors, which needs further studies.

  1. Geographic information systems and logistic regression for high-resolution malaria risk mapping in a rural settlement of the southern Brazilian Amazon.

    PubMed

    de Oliveira, Elaine Cristina; dos Santos, Emerson Soares; Zeilhofer, Peter; Souza-Santos, Reinaldo; Atanaka-Santos, Marina

    2013-11-15

    In Brazil, 99% of the cases of malaria are concentrated in the Amazon region, with high level of transmission. The objectives of the study were to use geographic information systems (GIS) analysis and logistic regression as a tool to identify and analyse the relative likelihood and its socio-environmental determinants of malaria infection in the Vale do Amanhecer rural settlement, Brazil. A GIS database of georeferenced malaria cases, recorded in 2005, and multiple explanatory data layers was built, based on a multispectral Landsat 5 TM image, digital map of the settlement blocks and a SRTM digital elevation model. Satellite imagery was used to map the spatial patterns of land use and cover (LUC) and to derive spectral indices of vegetation density (NDVI) and soil/vegetation humidity (VSHI). An Euclidian distance operator was applied to measure proximity of domiciles to potential mosquito breeding habitats and gold mining areas. The malaria risk model was generated by multiple logistic regression, in which environmental factors were considered as independent variables and the number of cases, binarized by a threshold value was the dependent variable. Out of a total of 336 cases of malaria, 133 positive slides were from inhabitants at Road 08, which corresponds to 37.60% of the notifications. The southern region of the settlement presented 276 cases and a greater number of domiciles in which more than ten cases/home were notified. From these, 102 (30.36%) cases were caused by Plasmodium falciparum and 174 (51.79%) cases by Plasmodium vivax. Malaria risk is the highest in the south of the settlement, associated with proximity to gold mining sites, intense land use, high levels of soil/vegetation humidity and low vegetation density. Mid-resolution, remote sensing data and GIS-derived distance measures can be successfully combined with digital maps of the housing location of (non-) infected inhabitants to predict relative likelihood of disease infection through the

  2. Geographic information systems and logistic regression for high-resolution malaria risk mapping in a rural settlement of the southern Brazilian Amazon

    PubMed Central

    2013-01-01

    Background In Brazil, 99% of the cases of malaria are concentrated in the Amazon region, with high level of transmission. The objectives of the study were to use geographic information systems (GIS) analysis and logistic regression as a tool to identify and analyse the relative likelihood and its socio-environmental determinants of malaria infection in the Vale do Amanhecer rural settlement, Brazil. Methods A GIS database of georeferenced malaria cases, recorded in 2005, and multiple explanatory data layers was built, based on a multispectral Landsat 5 TM image, digital map of the settlement blocks and a SRTM digital elevation model. Satellite imagery was used to map the spatial patterns of land use and cover (LUC) and to derive spectral indices of vegetation density (NDVI) and soil/vegetation humidity (VSHI). An Euclidian distance operator was applied to measure proximity of domiciles to potential mosquito breeding habitats and gold mining areas. The malaria risk model was generated by multiple logistic regression, in which environmental factors were considered as independent variables and the number of cases, binarized by a threshold value was the dependent variable. Results Out of a total of 336 cases of malaria, 133 positive slides were from inhabitants at Road 08, which corresponds to 37.60% of the notifications. The southern region of the settlement presented 276 cases and a greater number of domiciles in which more than ten cases/home were notified. From these, 102 (30.36%) cases were caused by Plasmodium falciparum and 174 (51.79%) cases by Plasmodium vivax. Malaria risk is the highest in the south of the settlement, associated with proximity to gold mining sites, intense land use, high levels of soil/vegetation humidity and low vegetation density. Conclusions Mid-resolution, remote sensing data and GIS-derived distance measures can be successfully combined with digital maps of the housing location of (non-) infected inhabitants to predict relative

  3. Malaria (For Parents)

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Malaria KidsHealth > For Parents > Malaria Print A A A ... Prevention Diagnosis and Treatment en español Malaria About Malaria Malaria is a common infection in hot, tropical ...

  4. How do risk preferences relate to malaria care-seeking behavior and the acceptability of a new health technology in Nigeria?

    PubMed

    Liu, Jenny; Modrek, Sepideh; Anyanti, Jennifer; Nwokolo, Ernest; De La Cruz, Anna; Schatzkin, Eric; Isiguzo, Chinwoke; Ujuju, Chinazo; Montagu, Dominic

    2014-09-05

    To reduce the burden of disease from malaria, innovative approaches are needed to engender behavior change. One unobservable, but fundamental trait-preferences for risk-may influence individuals' willingness to adopt new health technologies. We explore the association of risk preferences with malaria care-seeking behavior and the acceptability of malaria rapid diagnostic tests (RDTs) to inform RDT scale-up plans. In Oyo State, Nigeria, adult customers purchasing anti-malarial medications at selected drug shops took surveys and received an RDT as they exited. After an initial risk preference assessment via a simple lottery game choice, individuals were given their RDT result and treatment advice, and called four days later to assess treatment adherence. We used bivariable and multivariable regression analysis to assess the association of risk game choices with malaria care-seeking behaviors and RDT acceptability. Of 448 respondents, 63.2% chose the lottery game with zero variance in expected payout, 27.9% chose the game with low variance, and 8.9% chose the game with high variance. Compared to participants who chose lower variance games, individuals choosing higher variance games were older, less educated, more likely to be male, and were more likely to patronize lower quality drug shops, seek care immediately, and report complete disability due to their illness. In contrast, individuals choosing lower variance games were more likely to follow the correct treatment directions and were more likely to report an increase in their willingness to pay for an RDT compared to other risk groups, our two measures of RDT acceptability. Differences in estimated associations between risk game choices and selected care-seeking behaviors remained after controlling sociodemographic confounders. The uptake of health diagnostic information in terms of translating the RDT experience into willingness to pay for an RDT and treatment adherence to test results may vary according to risk

  5. Use of integrated malaria management reduces malaria in Kenya.

    PubMed

    Okech, Bernard A; Mwobobia, Isaac K; Kamau, Anthony; Muiruri, Samuel; Mutiso, Noah; Nyambura, Joyce; Mwatele, Cassian; Amano, Teruaki; Mwandawiro, Charles S

    2008-01-01

    During an entomological survey in preparation for malaria control interventions in Mwea division, the number of malaria cases at the Kimbimbi sub-district hospital was in a steady decline. The underlying factors for this reduction were unknown and needed to be identified before any malaria intervention tools were deployed in the area. We therefore set out to investigate the potential factors that could have contributed to the decline of malaria cases in the hospital by analyzing the malaria control knowledge, attitudes and practices (KAP) that the residents in Mwea applied in an integrated fashion, also known as integrated malaria management (IMM). Integrated Malaria Management was assessed among community members of Mwea division, central Kenya using KAP survey. The KAP study evaluated community members' malaria disease management practices at the home and hospitals, personal protection measures used at the household level and malaria transmission prevention methods relating to vector control. Concurrently, we also passively examined the prevalence of malaria parasite infection via outpatient admission records at the major referral hospital in the area. In addition we studied the mosquito vector population dynamics, the malaria sporozoite infection status and entomological inoculation rates (EIR) over an 8 month period in 6 villages to determine the risk of malaria transmission in the entire division. A total of 389 households in Mwea division were interviewed in the KAP study while 90 houses were surveyed in the entomological study. Ninety eight percent of the households knew about malaria disease while approximately 70% of households knew its symptoms and methods to manage it. Ninety seven percent of the interviewed households went to a health center for malaria diagnosis and treatment. Similarly a higher proportion (81%) used anti-malarial medicines bought from local pharmacies. Almost 90% of households reported owning and using an insecticide treated bed net

  6. Assessment of a remote sensing-based model for predicting malaria transmission risk in villages of Chiapas, Mexico

    NASA Technical Reports Server (NTRS)

    Beck, L. R.; Rodriguez, M. H.; Dister, S. W.; Rodriguez, A. D.; Washino, R. K.; Roberts, D. R.; Spanner, M. A.

    1997-01-01

    A blind test of two remote sensing-based models for predicting adult populations of Anopheles albimanus in villages, an indicator of malaria transmission risk, was conducted in southern Chiapas, Mexico. One model was developed using a discriminant analysis approach, while the other was based on regression analysis. The models were developed in 1992 for an area around Tapachula, Chiapas, using Landsat Thematic Mapper (TM) satellite data and geographic information system functions. Using two remotely sensed landscape elements, the discriminant model was able to successfully distinguish between villages with high and low An. albimanus abundance with an overall accuracy of 90%. To test the predictive capability of the models, multitemporal TM data were used to generate a landscape map of the Huixtla area, northwest of Tapachula, where the models were used to predict risk for 40 villages. The resulting predictions were not disclosed until the end of the test. Independently, An. albimanus abundance data were collected in the 40 randomly selected villages for which the predictions had been made. These data were subsequently used to assess the models' accuracies. The discriminant model accurately predicted 79% of the high-abundance villages and 50% of the low-abundance villages, for an overall accuracy of 70%. The regression model correctly identified seven of the 10 villages with the highest mosquito abundance. This test demonstrated that remote sensing-based models generated for one area can be used successfully in another, comparable area.

  7. Assessment of a remote sensing-based model for predicting malaria transmission risk in villages of Chiapas, Mexico

    NASA Technical Reports Server (NTRS)

    Beck, L. R.; Rodriguez, M. H.; Dister, S. W.; Rodriguez, A. D.; Washino, R. K.; Roberts, D. R.; Spanner, M. A.

    1997-01-01

    A blind test of two remote sensing-based models for predicting adult populations of Anopheles albimanus in villages, an indicator of malaria transmission risk, was conducted in southern Chiapas, Mexico. One model was developed using a discriminant analysis approach, while the other was based on regression analysis. The models were developed in 1992 for an area around Tapachula, Chiapas, using Landsat Thematic Mapper (TM) satellite data and geographic information system functions. Using two remotely sensed landscape elements, the discriminant model was able to successfully distinguish between villages with high and low An. albimanus abundance with an overall accuracy of 90%. To test the predictive capability of the models, multitemporal TM data were used to generate a landscape map of the Huixtla area, northwest of Tapachula, where the models were used to predict risk for 40 villages. The resulting predictions were not disclosed until the end of the test. Independently, An. albimanus abundance data were collected in the 40 randomly selected villages for which the predictions had been made. These data were subsequently used to assess the models' accuracies. The discriminant model accurately predicted 79% of the high-abundance villages and 50% of the low-abundance villages, for an overall accuracy of 70%. The regression model correctly identified seven of the 10 villages with the highest mosquito abundance. This test demonstrated that remote sensing-based models generated for one area can be used successfully in another, comparable area.

  8. Malaria resurgence risk in southern Europe: climate assessment in an historically endemic area of rice fields at the Mediterranean shore of Spain.

    PubMed

    Sainz-Elipe, Sandra; Latorre, Jose Manuel; Escosa, Raul; Masià, Montserrat; Fuentes, Marius Vicent; Mas-Coma, Santiago; Bargues, Maria Dolores

    2010-07-31

    International travel and immigration have been related with an increase of imported malaria cases. This fact and climate change, prolonging the period favouring vector development, require an analysis of the malaria transmission resurgence risk in areas of southern Europe. Such a study is made for the first time in Spain. The Ebro Delta historically endemic area was selected due to its rice field landscape, the presence of only one vector, Anopheles atroparvus, with densities similar to those it presented when malaria was present, in a situation which pronouncedly differs from already assessed potential resurgence areas in other Mediterranean countries, such as France and Italy, where many different Anopheles species coexist and a different vector species dominates. The transmission risk was assessed analysing: 1) climate diagrams including the minimum temperature for Plasmodium falciparum and Plasmodium vivax development; 2) monthly evolution of the Gradient Model Risk (GMR) index, specifying transmission risk period and number of potential Plasmodium generations; 3) ecological characteristics using remote sensing images with the Eurasia Land Cover characteristics database and the monthly evolution of the Normalized Difference Vegetation Index (NDVI); 4) evaluation of A. atroparvus population dynamics. Climatological analyses and GMR index show that a transmission risk presently exists, lasting from May until September for P. falciparum, and from May until October for P. vivax. The GMR index shows that the temperature increase does not actually mean a transmission risk increase if accompanied by a precipitation decrease reducing the number of parasite generations and transmission period. Nevertheless, this limitation is offset by the artificial flooding of the rice fields. Maximum NDVI values and A. atroparvus maximum abundance correspond to months with maximum growth of the rice fields. The Ebro Delta presents the ecological characteristics that favour

  9. Malaria resurgence risk in southern Europe: climate assessment in an historically endemic area of rice fields at the Mediterranean shore of Spain

    PubMed Central

    2010-01-01

    Background International travel and immigration have been related with an increase of imported malaria cases. This fact and climate change, prolonging the period favouring vector development, require an analysis of the malaria transmission resurgence risk in areas of southern Europe. Such a study is made for the first time in Spain. The Ebro Delta historically endemic area was selected due to its rice field landscape, the presence of only one vector, Anopheles atroparvus, with densities similar to those it presented when malaria was present, in a situation which pronouncedly differs from already assessed potential resurgence areas in other Mediterranean countries, such as France and Italy, where many different Anopheles species coexist and a different vector species dominates. Methods The transmission risk was assessed analysing: 1) climate diagrams including the minimum temperature for Plasmodium falciparum and Plasmodium vivax development; 2) monthly evolution of the Gradient Model Risk (GMR) index, specifying transmission risk period and number of potential Plasmodium generations; 3) ecological characteristics using remote sensing images with the Eurasia Land Cover characteristics database and the monthly evolution of the Normalized Difference Vegetation Index (NDVI); 4) evaluation of A. atroparvus population dynamics. Results Climatological analyses and GMR index show that a transmission risk presently exists, lasting from May until September for P. falciparum, and from May until October for P. vivax. The GMR index shows that the temperature increase does not actually mean a transmission risk increase if accompanied by a precipitation decrease reducing the number of parasite generations and transmission period. Nevertheless, this limitation is offset by the artificial flooding of the rice fields. Maximum NDVI values and A. atroparvus maximum abundance correspond to months with maximum growth of the rice fields. Conclusions The Ebro Delta presents the ecological

  10. Imported malaria.

    PubMed

    Schultz, M G

    1974-01-01

    There have been 4 waves of imported malaria in the USA. They occurred during the colonization of the country and during the Second World War, the UN Police Action in Korea, and the Viet-Nam conflict. The first 3 episodes are briefly described and the data on imported malaria from Viet-Nam are discussed in detail.Endemic malaria is resurgent in many tropical countries and international travel is also on the rise. This increases the likelihood of malaria being imported from an endemic area and introduced into a receptive area. The best defence for countries threatened by imported malaria is a vigorous surveillance programme. The principles of surveillance are discussed and an example of their application is provided by a description of the methods used to conduct surveillance of malaria in the USA.

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

    PubMed

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

    2017-06-09

    The emergence of human malaria due to the monkey parasite Plasmodium knowlesi threatens elimination efforts in southeast Asia. Changes in land use are thought to be driving the rise in reported P knowlesi cases, but the role of individual-level factors is unclear. To address this knowledge gap we assessed human and environmental factors associated with zoonotic knowlesi malaria risk. We did this population-based case-control study over a 2 year period in the state of Sabah in Malaysia. We enrolled cases with microscopy-positive, PCR-confirmed malaria who presented to two primary referral hospitals serving the adjacent districts of Kudat and Kota Marudu. We randomly selected three malaria-negative community controls per case, who were matched by village within 2 weeks of case detection. We obtained questionnaire data on demographics, behaviour, and residential malaria risk factors, and we also assessed glucose-6-phosphate dehydrogenase (G6PD) enzyme activity. We used conditional logistic regression models to evaluate exposure risk between P knowlesi cases and controls, and between P knowlesi and human-only Plasmodium spp malaria cases. From Dec 5, 2012, to Jan 30, 2015, we screened 414 patients and subsequently enrolled 229 cases with P knowlesi malaria mono-infection and 91 cases with other Plasmodium spp infection. We enrolled 953 matched controls, including 683 matched to P knowlesi cases and 270 matched to non-P knowlesi cases. Age 15 years or older (adjusted odds ratio [aOR] 4·16, 95% CI 2·09-8·29, p<0·0001), male gender (4·20, 2·54-6·97, p<0·0001), plantation work (3·50, CI, 1·34-9·15, p=0·011), sleeping outside (3·61, 1·48-8·85, p=0·0049), travel (2·48, 1·45-4·23, p=0·0010), being aware of the presence of monkeys in the past 4 weeks (3·35, 1·91-5·88, p<0·0001), and having open eaves or gaps in walls (2·18, 1·33-3·59, p=0·0021) were independently associated with increased risk of symptomatic P knowlesi infection. Farming occupation

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

    PubMed Central

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

    2017-01-01

    Summary Background The emergence of human malaria due to the monkey parasite Plasmodium knowlesi threatens elimination efforts in southeast Asia. Changes in land use are thought to be driving the rise in reported P knowlesi cases, but the role of individual-level factors is unclear. To address this knowledge gap we assessed human and environmental factors associated with zoonotic knowlesi malaria risk. Methods We did this population-based case-control study over a 2 year period in the state of Sabah in Malaysia. We enrolled cases with microscopy-positive, PCR-confirmed malaria who presented to two primary referral hospitals serving the adjacent districts of Kudat and Kota Marudu. We randomly selected three malaria-negative community controls per case, who were matched by village within 2 weeks of case detection. We obtained questionnaire data on demographics, behaviour, and residential malaria risk factors, and we also assessed glucose-6-phosphate dehydrogenase (G6PD) enzyme activity. We used conditional logistic regression models to evaluate exposure risk between P knowlesi cases and controls, and between P knowlesi and human-only Plasmodium spp malaria cases. Findings From Dec 5, 2012, to Jan 30, 2015, we screened 414 patients and subsequently enrolled 229 cases with P knowlesi malaria mono-infection and 91 cases with other Plasmodium spp infection. We enrolled 953 matched controls, including 683 matched to P knowlesi cases and 270 matched to non-P knowlesi cases. Age 15 years or older (adjusted odds ratio [aOR] 4·16, 95% CI 2·09–8·29, p<0·0001), male gender (4·20, 2·54–6·97, p<0·0001), plantation work (3·50, CI, 1·34–9·15, p=0·011), sleeping outside (3·61, 1·48–8·85, p=0·0049), travel (2·48, 1·45–4·23, p=0·0010), being aware of the presence of monkeys in the past 4 weeks (3·35, 1·91–5·88, p<0·0001), and having open eaves or gaps in walls (2·18, 1·33–3·59, p=0·0021) were independently associated with increased risk of

  13. [Glucose 6-phosphate dehydrogenase deficiency: a protection against malaria and a risk for hemolytic accidents].

    PubMed

    Wajcman, Henri; Galactéros, Frédéric

    2004-08-01

    Glucose 6-phosphate dehydrogenase (G6PD) catalyses the first step of the pentose phosphate pathway, which in the RBC leads to the formation of NADPH, essential to prevent the cell from an oxidative stress. Worldwide, more than 400 million people (90% being males) are affected by G6PD deficiency, in regions that are, or have been, endemic for malaria and in populations originating from these regions. RBCs with low G6PD activity offer a hostile environment to parasite growth and thus an advantage to G6PD deficiency carriers. The counterpart of this protective effect is an increased susceptibility to oxidants such as some foods (fava beans), drugs (anti-malarial or sulphonamides), or various chemicals. In the case of G6PD deficiency, the hypothesis of a convergent evolution between parasite, protecting mutation, and cultural traditions (food, skin painting...) has been proposed. Near to 150 different G6PD variants have been described, which are classified into four types, according to their clinical effects. Several variants, such as the G6PD A- or the Mediterranean variant, reach the polymorphism level in endemic regions. The recent determination of the three-dimensional structure of this enzyme allows one to explain now the mechanisms of the disorders in terms of structure-function relationship.

  14. Malaria entomological risk factors in relation to land cover in the Lower Caura River Basin, Venezuela

    PubMed Central

    Rubio-Palis, Yasmin; Bevilacqua, Mariapia; Medina, Domingo Alberto; Moreno, Jorge Ernesto; Cárdenas, Lya; Sánchez, Víctor; Estrada, Yarys; Anaya, William; Martínez, Ángela

    2013-01-01

    To explore the effects of deforestation and resulting differences in vegetation and land cover on entomological parameters, such as anopheline species composition, abundance, biting rate, parity and entomological inoculation rate (EIR), three villages were selected in the Lower Caura River Basin, state of Bolívar, Venezuela. All-night mosquito collections were conducted between March 2008-January 2009 using CDC light traps and Mosquito Magnet(r) Liberty Plus. Human landing catches were performed between 06:00 pm-10:00 pm, when anophelines were most active. Four types of vegetation were identified. The Annual Parasite Index was not correlated with the type of vegetation. The least abundantly forested village had the highest anopheline abundance, biting rate and species diversity. Anopheles darlingi and Anopheles nuneztovari were the most abundant species and were collected in all three villages. Both species showed unique biting cycles. The more abundantly forested village of El Palmar reported the highest EIR. The results confirmed previous observations that the impacts of deforestation and resulting changes in vegetation cover on malaria transmission are complex and vary locally. PMID:23579803

  15. Malaria entomological risk factors in relation to land cover in the Lower Caura River Basin, Venezuela.

    PubMed

    Rubio-Palis, Yasmin; Bevilacqua, Mariapia; Medina, Domingo Alberto; Moreno, Jorge Ernesto; Cárdenas, Lya; Sánchez, Víctor; Estrada, Yarys; Anaya, William; Martínez, Ángela

    2013-04-01

    To explore the effects of deforestation and resulting differences in vegetation and land cover on entomological parameters, such as anopheline species composition, abundance, biting rate, parity and entomological inoculation rate (EIR), three villages were selected in the Lower Caura River Basin, state of Bolívar, Venezuela. All-night mosquito collections were conducted between March 2008-January 2009 using CDC light traps and Mosquito Magnet® Liberty Plus. Human landing catches were performed between 06:00 pm-10:00 pm, when anophelines were most active. Four types of vegetation were identified. The Annual Parasite Index was not correlated with the type of vegetation. The least abundantly forested village had the highest anopheline abundance, biting rate and species diversity. Anopheles darlingi and Anopheles nuneztovari were the most abundant species and were collected in all three villages. Both species showed unique biting cycles. The more abundantly forested village of El Palmar reported the highest EIR. The results confirmed previous observations that the impacts of deforestation and resulting changes in vegetation cover on malaria transmission are complex and vary locally.

  16. 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

  17. [Malaria in the Rostov Region: retrospective analysis of the malaria situation in 1952-2007].

    PubMed

    Kormilenko, I V; Aĭdinov, G T; Shvager, M M

    2009-01-01

    In the Rostov Region, no cases of local malaria transmission have been notified since 1958, but cases of import malaria are recorded every year. The region is one of malaria-susceptible areas in the Russian Federation, which is characterized by intensive migration, the malariogenic potential sufficient for local transmission (malariogenic index 1.2), and the optimum conditions for resurgence of malaria when it is imported. The prevention of undesirable consequences of malaria importation requires the strict monitoring of feverish patients, cohorts of high-risk patients who go for trips to malaria-endemic countries.

  18. 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.

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

    PubMed

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

    2014-08-22

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

  20. Low-Quality Housing Is Associated With Increased Risk of Malaria Infection: A National Population-Based Study From the Low Transmission Setting of Swaziland.

    PubMed

    Dlamini, Nomcebo; Hsiang, Michelle S; Ntshalintshali, Nyasatu; Pindolia, Deepa; Allen, Regan; Nhlabathi, Nomcebo; Novotny, Joseph; Kang Dufour, Mi-Suk; Midekisa, Alemayehu; Gosling, Roly; LeMenach, Arnaud; Cohen, Justin; Dorsey, Grant; Greenhouse, Bryan; Kunene, Simon

    2017-01-01

    Low-quality housing may confer risk of malaria infection, but evidence in low transmission settings is limited. To examine the relationship between individual level housing quality and locally acquired infection in children and adults, a population-based cross-sectional analysis was performed using existing surveillance data from the low transmission setting of Swaziland. From 2012 to 2015, cases were identified through standard diagnostics in health facilities and by loop-mediated isothermal amplification in active surveillance, with uninfected subjects being household members and neighbors. Housing was visually assessed in a home visit and then classified as low, high, or medium quality, based on housing components being traditional, modern, or both, respectively. Overall, 11426 individuals were included in the study: 10960 uninfected and 466 infected (301 symptomatic and 165 asymptomatic). Six percent resided in low-quality houses, 26% in medium-quality houses, and 68% in high-quality houses. In adjusted models, low- and medium-quality construction was associated with increased risk of malaria compared with high-quality construction (adjusted odds ratio [AOR], 2.11 and 95% confidence interval [CI], 1.26-3.53 for low vs high; AOR, 1.56 and 95% CI, 1.15-2.11 for medium vs high). The relationship was independent of vector control, which also conferred a protective effect (AOR, 0.67; 95% CI, .50-.90) for sleeping under an insecticide-treated bed net or a sprayed structure compared with neither. Our study adds to the limited literature on housing quality and malaria risk from low transmission settings. Housing improvements may offer an attractive and sustainable additional strategy to support countries in malaria elimination.

  1. Low-Quality Housing Is Associated With Increased Risk of Malaria Infection: A National Population-Based Study From the Low Transmission Setting of Swaziland

    PubMed Central

    Dlamini, Nomcebo; Ntshalintshali, Nyasatu; Pindolia, Deepa; Allen, Regan; Nhlabathi, Nomcebo; Novotny, Joseph; Kang Dufour, Mi-Suk; Midekisa, Alemayehu; Gosling, Roly; LeMenach, Arnaud; Cohen, Justin; Dorsey, Grant; Greenhouse, Bryan; Kunene, Simon

    2017-01-01

    Abstract Background. Low-quality housing may confer risk of malaria infection, but evidence in low transmission settings is limited. Methods. To examine the relationship between individual level housing quality and locally acquired infection in children and adults, a population-based cross-sectional analysis was performed using existing surveillance data from the low transmission setting of Swaziland. From 2012 to 2015, cases were identified through standard diagnostics in health facilities and by loop-mediated isothermal amplification in active surveillance, with uninfected subjects being household members and neighbors. Housing was visually assessed in a home visit and then classified as low, high, or medium quality, based on housing components being traditional, modern, or both, respectively. Results. Overall, 11426 individuals were included in the study: 10960 uninfected and 466 infected (301 symptomatic and 165 asymptomatic). Six percent resided in low-quality houses, 26% in medium-quality houses, and 68% in high-quality houses. In adjusted models, low- and medium-quality construction was associated with increased risk of malaria compared with high-quality construction (adjusted odds ratio [AOR], 2.11 and 95% confidence interval [CI], 1.26–3.53 for low vs high; AOR, 1.56 and 95% CI, 1.15–2.11 for medium vs high). The relationship was independent of vector control, which also conferred a protective effect (AOR, 0.67; 95% CI, .50–.90) for sleeping under an insecticide-treated bed net or a sprayed structure compared with neither. Conclusions. Our study adds to the limited literature on housing quality and malaria risk from low transmission settings. Housing improvements may offer an attractive and sustainable additional strategy to support countries in malaria elimination. PMID:28580365

  2. Risk of drug resistance in Plasmodium falciparum malaria therapy-a systematic review and meta-analysis.

    PubMed

    Zhou, Li-Juan; Xia, Jing; Wei, Hai-Xia; Liu, Xiao-Jun; Peng, Hong-Juan

    2017-02-01

    Plasmodium falciparum is responsible for the vast majority of the morbidity and mortality associated with malaria infection globally. Although a number of studies have reported the emergence of drug resistance in different therapies for P. falciparum infection, the degree of the drug resistance in different antimalarials is still unclear. This research investigated the risk of drug resistance in the therapies with different medications based on meta-analyses. Relevant original randomized control trials (RCTs) were searched in all available electronic databases. Pooled relative risks (RRs) with 95% confidence intervals (95% CIs) were used to evaluate the risk of drug resistance resulting from different treatments. Seventy-eight studies were included in the meta-analysis to compare drug resistance in the treatment of P. falciparum infections and yielded the following results: chloroquine (CQ) > sulfadoxine-pyrimethamine (SP) (RR = 3.67, p < 0.001 ), mefloquine (MQ) < SP (RR = 0.26, p < 0.001), artesunate + sulfadoxine-pyrimethamine (AS + SP) > artemether + lumefantrine (AL) (RR = 2.94, p < 0.001), dihydroartemisinin + piperaquine (DHA + PQ) < AL (RR = 0.7, p < 0.05), and non-artemisinin-based combination therapies (NACTs) > artemisinin-based combination therapies (ACTs) (RR = 1.93, p < 0.001); no significant difference was found in amodiaquine (AQ) vs. SP, AS + AQ vs. AS + SP, AS + AQ vs. AL, or AS + MQ vs. AL. These results presented a global view for the current status of antimalarial drug resistance and provided a guidance for choice of antimalarials for efficient treatment and prolonging the life span of the current effective antimalarial drugs.

  3. Retail supply of malaria-related drugs in rural Tanzania: risks and opportunities.

    PubMed

    Goodman, Catherine; Kachur, S Patrick; Abdulla, Salim; Mwageni, Eleuther; Nyoni, Joyce; Schellenberg, Joanna A; Mills, Anne; Bloland, Peter

    2004-06-01

    To characterize availability of fever and malaria medicines within the retail sector in rural Tanzania, assess the likely public health implications, and identify opportunities for policy interventions to increase the coverage of effective treatment. A census of retailers selling drugs was undertaken in the areas under demographic surveillance in four Tanzanian districts, using a structured questionnaire. Drugs were stocked by two types of retailer: a large number of general retailers (n = 675) and a relatively small number of drug shops (n = 43). Almost all outlets stocked antipyretics/painkillers. One-third of general retailers stocking drugs had antimalarials, usually chloroquine alone. Almost all drug shops stocked antimalarials (98%): nearly all had chloroquine, 42% stocked quinine, 37% sulphadoxine-pyrimethamine and 30% amodiaquine. A large number of antimalarial brands were available. Population ratios indicate the relative accessibility of retail drug providers compared with health facilities. Drug shop staff generally travelled long distances to buy from drugs wholesalers or pharmacies. General retailers bought mainly from local general wholesalers, with a few general wholesalers accounting for a high proportion of all sources cited. Drugs were widely available from a large number of retail outlets. Potential negative implications include provision of ineffective drugs, confusion over brand names, uncontrolled use of antimalarials, and the availability of components of potential combination therapy regimens as monotherapies. On the other hand, this active and highly accessible retail market provides opportunities for improving the coverage of effective antimalarial treatment. Interventions targeted at all drug retailers are likely to be costly to deliver and difficult to sustain, but two promising points for targeted intervention are drug shops and selected general wholesalers. Retail quality may also be improved through consumer education, and

  4. Results from a four-year study on the prevalence of nosocomial infections in Franche-Comté: attempt to rank the risk of nosocomial infection.

    PubMed

    Floret, N; Bailly, P; Bertrand, X; Claude, B; Louis-Martinet, C; Picard, A; Tueffert, N; Talon, D

    2006-08-01

    The aim of this study was to rank the risk of nosocomial infection (NI) according to patient type by analysing the results of annual prevalence studies carried out in Franche-Comté from 2001 to 2004. Patients (N=14,905) were divided into four categories according to the number of endogenous risk factors (age, immunodepression, MacCabe score). The overall prevalence of infection was 6.1% and varied according to the category of patient from 1.93% (no risk factors) to 15.2% (three risk factors). The frequencies of NI related to an invasive procedure and to cross-contamination with multi-drug-resistant (MDR) bacteria were 30.9% and 12.3%, respectively; these percentages did not depend on the type of patient. The prevalence of NI decreased over time for patients with two or three risk factors, but was stable for patients with no risk factors. More than 40% of NIs were potentially avoidable (related to invasive procedures or involving cross-transmission of an MDR bacterium) regardless of the category of patient. This study suggests that at least 30% of NIs could be avoided.

  5. Estimating the Global Clinical Burden of Plasmodium falciparum Malaria in 2007

    PubMed Central

    Hay, Simon I.; Okiro, Emelda A.; Gething, Peter W.; Patil, Anand P.; Tatem, Andrew J.; Guerra, Carlos A.; Snow, Robert W.

    2010-01-01

    Background The epidemiology of malaria makes surveillance-based methods of estimating its disease burden problematic. Cartographic approaches have provided alternative malaria burden estimates, but there remains widespread misunderstanding about their derivation and fidelity. The aims of this study are to present a new cartographic technique and its application for deriving global clinical burden estimates of Plasmodium falciparum malaria for 2007, and to compare these estimates and their likely precision with those derived under existing surveillance-based approaches. Methods and Findings In seven of the 87 countries endemic for P. falciparum malaria, the health reporting infrastructure was deemed sufficiently rigorous for case reports to be used verbatim. In the remaining countries, the mapped extent of unstable and stable P. falciparum malaria transmission was first determined. Estimates of the plausible incidence range of clinical cases were then calculated within the spatial limits of unstable transmission. A modelled relationship between clinical incidence and prevalence was used, together with new maps of P. falciparum malaria endemicity, to estimate incidence in areas of stable transmission, and geostatistical joint simulation was used to quantify uncertainty in these estimates at national, regional, and global scales. Combining these estimates for all areas of transmission risk resulted in 451 million (95% credible interval 349–552 million) clinical cases of P. falciparum malaria in 2007. Almost all of this burden of morbidity occurred in areas of stable transmission. More than half of all estimated P. falciparum clinical cases and associated uncertainty occurred in India, Nigeria, the Democratic Republic of the Congo (DRC), and Myanmar (Burma), where 1.405 billion people are at risk. Recent surveillance-based methods of burden estimation were then reviewed and discrepancies in national estimates explored. When these cartographically derived national

  6. Heterogeneity and Changes in Inequality of Malaria Risk after Introduction of Insecticide-Treated Bed Nets in Macha, Zambia

    PubMed Central

    Norris, Laura C.; Norris, Douglas E.

    2013-01-01

    In 2007, the first free mass distribution of insecticide-treated bed nets (ITNs) occurred in southern Zambia. To determine the effect of ITNs on heterogeneity in biting rates, human DNA from Anopheles arabiensis blood meals was genotyped to determine the number of hosts that had contributed to the blood meals. The multiple feeding rate decreased from 18.9% pre-ITN to 9.1% post-ITN, suggesting that mosquito biting had focused onto a smaller fraction of the population. Pre-ITN, 20% of persons in a household provided 40% of blood meals, which increased to 59% post-ITN. To measure heterogeneity over a larger scale, mosquitoes were collected in 90 households in two village areas. Of these households, 25% contributed 78.1% of An. arabiensis, and households with high frequencies of An. arabiensis were significantly spatially clustered. The results indicate that substantial heterogeneity in malaria risk exists at local and household levels, and household-level heterogeneity may be influenced by interventions, such as ITNs. PMID:23382169

  7. Response to diazepam in children with malaria-induced seizures.

    PubMed

    Ikumi, M L; Muchohi, S N; Ohuma, E O; Kokwaro, G O; Newton, C R J C

    2008-12-01

    Malaria infection reduces the binding capacity of benzodiazepine receptors in mice. We studied the efficacy of diazepam terminating seizures in children with falciparum malaria. Diazepam stopped seizures in fewer patients with malaria parasitaemia (chi(2)=3.93, P=0.047) and those with clinical diagnosis of malaria (chi(2)=9.84, P=0.002) compared to those without. However malaria was not identified as an independent risk factor for diazepam's failure to stop seizures in children.

  8. [The ABCD of malaria prevention in pediatric travelers].

    PubMed

    Berberian, Griselda; Rosanova, M Teresa; Torroija, Cecilia; Praino, M Laura

    2014-10-01

    The development and spread of drug resistant malaria parasites, population and travelers movements to malaria zones have led to the resurgence of malaria as a global health problem. Estimates suggest that 660,000 deaths occur annually, mainly in infants, children and pregnant woman. Disease knowledge and protection against mosquito bites are the first line of defense against malaria. Malaria chemoprophylaxis adds to these measures, it must be evaluated based on the individual risk.

  9. University Rankings in China

    ERIC Educational Resources Information Center

    Liu, Nian Cai; Liu, Li

    2005-01-01

    Since the mid 1990s of last Century, university rankings have become very popular in China. Six institutions have published such rankings; some of them have also detailed their ranking methodologies. This paper features a general introduction to university ranking in China, and to the methodologies of each ranking discussed. The paper also…

  10. Eradicating malaria.

    PubMed

    Breman, Joel G

    2009-01-01

    The renewed interest in malaria research and control is based on the intolerable toll this disease takes on young children and pregnant women in Africa and other vulnerable populations; 150 to 300 children die each hour from malaria amounting to 1 to 2 million deaths yearly. Malaria-induced neurologic impairment, anemia, hypoglycemia, and low birth weight imperil normal development and survival. Resistance of Plasmodium falciparum to drugs and Anopheles mosquitoes to insecticides has stimulated discovery and development of artemisinin-based combination treatments (ACTs) and other drugs, long-lasting insecticide-treated bednets (with synthetic pyrethroids) and a search for non-toxic, long-lasting, affordable insecticides for indoor residual spraying (IRS). Malaria vaccine development and testing are progressing rapidly and a recombinant protein (RTS,S/AS02A) directed against the circumsporozoite protein is soon to be in Phase 3 trials. Support for malaria control, research, and advocacy through the Global Fund for HIV/AIDS, Tuberculosis and Malaria, the U.S. President's Malaria Initiative, the Bill & Melinda Gates Foundation, WHO and other organizations is resulting in decreasing morbidity and mortality in many malarious countries. Sustainability of effective programs through training and institution strengthening will be the key to malaria elimination coupled with improved surveillance and targeted research.

  11. Sustained use of insecticide-treated curtains is not associated with greater circulation of drug-resistant malaria parasites, or with higher risk of treatment failure among children with uncomplicated malaria in Burkina Faso.

    PubMed

    Diallo, Diadier A; Sutherland, Colin; Nebié, Issa; Konaté, Amadou T; Ord, Rosalynn; Pota, Hirva; Roper, Cally; Ilboudo-Sanogo, Edith; Greenwood, Brian M; Cousens, Simon N

    2007-02-01

    The impact of vector control measures on the evolution of antimalarial drug resistance is an important issue for malaria control programs. We investigated whether the in vivo efficacy of chloroquine (CQ) in children aged 6-59 months with uncomplicated malaria differed in 9 villages that had benefited from long-term use of insecticide-treated curtains (ITCs) and in 9 nearby non-ITC villages. We also compared the prevalence of genetic markers of resistance to CQ and sulfadoxine-pyrimethamine (SP) between the two groups of villages. The study enrolled 1,035 children with uncomplicated malaria and 231 infected but asymptomatic children. After taking account of re-infections, the proportions of children who experienced clinical failure after treatment with CQ were 14% and 19% in ITC and non-ITC villages, respectively (OR = 0.68; 95% CI: 0.39, 1.18). Parasitologic failure was observed in 49% of children in ITC villages and 58% of children in non-ITC villages (OR = 0.71 95%CI: 0.44, 1.13). The proportion of symptomatic children who harbored parasites carrying the pfcrt-76T allele was 43% in ITC villages and 40% in non-ITC villages (OR = 1.09; 95%CI: 0.80, 1.50). The pfmdr1-86Y allele was detected in 31% and 29% of children in the two groups of villages (OR = 1.14; 95%CI: 0.75, 1.72). Triple mutations in the dhfr gene were observed in 12% of children in both groups. No double mutations in the dhps gene were observed. Similar results were observed in asymptomatic children. In this setting, ITC use was not associated with increased circulation of parasites resistant to standard antimalarial drugs, or with a greater risk of treatment failure among children less than 5 years of age.

  12. Impact of an Intervention to Minimize Overdiagnosis of Malaria Cases in a Low Risk Kenyan sub-County.

    PubMed

    Njuguna, John; Menge, Daniel; Nzou, Joseph; Chege, Charles

    2015-08-01

    Overdiagnosis of malaria cases hampers malaria control in developing countries. Due to lack of diagnostics, febrile cases are treated using signs and symptoms. We evaluated an intervention to minimize overdiagnosis in Ijara sub-County, Kenya. Health workers were trained on case management and rapid diagnostic tests provided in late 2011. Malaria outpatient morbidity was assessed a year before and after the intervention coupled with data on rapid diagnostic tests consumption. The number of diagnosed malaria cases decreased from 15,615 in 2011 to 1,892 in 2012. This represents an 87.8% decrease. There was a significant difference in number of diagnosed monthly malaria cases during the pre-intervention (Mean = 1,299, SD = 550.4) and post-intervention periods (Mean = 158, SD = 160.9, t (12.9) = 6.9, p =.000, two tailed). Mean monthly consumption of rapid diagnostic tests was 730, with 5.2% testing positive. This intervention reduced overdiagnosis and overtreatment of malaria cases.

  13. [Malaria in the Americas].

    PubMed

    Carme, B; Venturin, C

    1999-01-01

    In 1996, malaria involving Plasmodium vivax, Plasmodium falciparum, and, to a lesser extent, Plasmodium malariae was endemic in 21 countries in the Americas. The Amazon river basin and bordering areas including the Guyanas were the most affected zones. Until the mid 1970s, endemic malaria appeared to be under control. However in the ensuing 15 year period, the situation deteriorated drastically. Although trends varied depending on location, aggregate indexes indicated a twofold increase with recrudescence in previously settled areas and emergence in newly populated zones. Since 1990, the situation has worsened further in some areas where increased incidences have been associated with a high levels of drug-resistant Plasmodium falciparum. However this species remains in minority except in the Guyanas where the highest annual incidences (100 to 500 cases per 1000) and the most drug-resistant Plasmodium have been reported. The causes underlying this deterioration are numerous and complex. In regions naturally prone to transmission of the disease, outbreaks have been intensified by unrestrained settlement. The resulting deforestation has created new breeding areas for Anopheles darlingi, the main vector of malaria in the Americas. Migration of poor populations to newly opened farming and mining areas has created highly exposed areas for malaria infection. Implementation of adequate medical care and prevention measures has been hindered by a lack of money and sociopolitical unrest. Climatic phenomenon related the El Nino have also been favorable to the return of malaria to the region. Except with regard to financial resources and political unrest, the same risk factors for malaria are present in French Guiana.

  14. The treatment of malaria.

    PubMed

    White, N J

    1996-09-12

    Increasing drug resistance in Plasmodium falciparum and a resurgence of malaria in tropical areas have effected a change in treatment of malaria in the last two decades. Symptoms of malaria are fever, chills, headache, and malaise. The prognosis worsens as the parasite counts, counts of mature parasites, and counts of neutrophils containing pigment increase. Treatment depends on severity, age of patient, degree of background immunity, likely pattern of susceptibility to antimalarial drugs, and the cost and availability of drugs. Chloroquine should be used for P. vivax, P. malariae, and P. ovale. P. vivax has shown high resistance to chloroquine in Oceania, however. Primaquine may be needed to treat P. vivax and P. ovale to rid the body of hypnozoites that survive in the liver. Chloroquine can treat P. falciparum infections acquired in North Africa, Central America north of the Panama Canal, Haiti, or the Middle East but not in most of Africa and some parts of Asia and South America. In areas of low grade resistance to chloroquine, amodiaquine can be used to effectively treat falciparum malaria. A combination of sulfadoxine-pyrimethamine is responsive to falciparum infections with high grade resistance to chloroquine. Mefloquine, halofantrine, or quinine with tetracycline can be used to treat multidrug-resistant P. falciparum. Derivatives of artemisinin obtained from qinghao or sweet wormwood developed as pharmaceuticals in China are the most rapidly acting of all antimalarial drugs. Children tend to tolerate antimalarial drugs well. Children who weigh less than 15 kg should not be given mefloquine. Health workers should not prescribe primaquine to pregnant women or newborns due to the risk of hemolysis. Chloroquine, sulfadoxine-pyrimethamine, quinine, and quinidine can be safely given in therapeutic doses throughout pregnancy. Clinical manifestations of severe malaria are hypoglycemia, convulsions, severe anemia, acute renal failure, jaundice, pulmonary edema

  15. A Chemical Risk Ranking and Scoring Method for the Selection of Harmful Substances to be Specially Controlled in Occupational Environments

    PubMed Central

    Shin, Saemi; Moon, Hyung-Il; Lee, Kwon Seob; Hong, Mun Ki; Byeon, Sang-Hoon

    2014-01-01

    This study aimed to devise a method for prioritizing hazardous chemicals for further regulatory action. To accomplish this objective, we chose appropriate indicators and algorithms. Nine indicators from the Globally Harmonized System of Classification and Labeling of Chemicals were used to identify categories to which the authors assigned numerical scores. Exposure indicators included handling volume, distribution, and exposure level. To test the method devised by this study, sixty-two harmful substances controlled by the Occupational Safety and Health Act in Korea, including acrylamide, acrylonitrile, and styrene were ranked using this proposed method. The correlation coefficients between total score and each indicator ranged from 0.160 to 0.641, and those between total score and hazard indicators ranged from 0.603 to 0.641. The latter were higher than the correlation coefficients between total score and exposure indicators, which ranged from 0.160 to 0.421. Correlations between individual indicators were low (−0.240 to 0.376), except for those between handling volume and distribution (0.613), suggesting that each indicator was not strongly correlated. The low correlations between each indicator mean that the indicators and independent and were well chosen for prioritizing harmful chemicals. This method proposed by this study can improve the cost efficiency of chemical management as utilized in occupational regulatory systems. PMID:25419874

  16. A chemical risk ranking and scoring method for the selection of harmful substances to be specially controlled in occupational environments.

    PubMed

    Shin, Saemi; Moon, Hyung-Il; Lee, Kwon Seob; Hong, Mun Ki; Byeon, Sang-Hoon

    2014-11-20

    This study aimed to devise a method for prioritizing hazardous chemicals for further regulatory action. To accomplish this objective, we chose appropriate indicators and algorithms. Nine indicators from the Globally Harmonized System of Classification and Labeling of Chemicals were used to identify categories to which the authors assigned numerical scores. Exposure indicators included handling volume, distribution, and exposure level. To test the method devised by this study, sixty-two harmful substances controlled by the Occupational Safety and Health Act in Korea, including acrylamide, acrylonitrile, and styrene were ranked using this proposed method. The correlation coefficients between total score and each indicator ranged from 0.160 to 0.641, and those between total score and hazard indicators ranged from 0.603 to 0.641. The latter were higher than the correlation coefficients between total score and exposure indicators, which ranged from 0.160 to 0.421. Correlations between individual indicators were low (-0.240 to 0.376), except for those between handling volume and distribution (0.613), suggesting that each indicator was not strongly correlated. The low correlations between each indicator mean that the indicators and independent and were well chosen for prioritizing harmful chemicals. This method proposed by this study can improve the cost efficiency of chemical management as utilized in occupational regulatory systems.

  17. Network-based gene prediction for Plasmodium falciparum malaria towards genetics-based drug discovery.

    PubMed

    Chen, Yang; Xu, Rong

    2015-01-01

    Malaria is the most deadly parasitic infectious disease. Existing drug treatments have limited efficacy in malaria elimination, and the complex pathogenesis of the disease is not fully understood. Detecting novel malaria-associated genes not only contributes in revealing the disease pathogenesis, but also facilitates discovering new targets for anti-malaria drugs. In this study, we developed a network-based approach to predict malaria-associated genes. We constructed a cross-species network to integrate human-human, parasite-parasite and human-parasite protein interactions. Then we extended the random walk algorithm on this network, and used known malaria genes as the seeds to find novel candidate genes for malaria. We validated our algorithms using 77 known malaria genes: 14 human genes and 63 parasite genes were ranked averagely within top 2% and top 4%, respectively among human and parasite genomes. We also evaluated our method for predicting novel malaria genes using a set of 27 genes with literature supporting evidence. Our approach ranked 12 genes within top 1% and 24 genes within top 5%. In addition, we demonstrated that top-ranked candied genes were enriched for drug targets, and identified commonalities underlying top-ranked malaria genes through pathway analysis. In summary, the candidate malaria-associated genes predicted by our data-driven approach have the potential to guide genetics-based anti-malaria drug discovery.

  18. Network-based gene prediction for Plasmodium falciparum malaria towards genetics-based drug discovery

    PubMed Central

    2015-01-01

    Background Malaria is the most deadly parasitic infectious disease. Existing drug treatments have limited efficacy in malaria elimination, and the complex pathogenesis of the disease is not fully understood. Detecting novel malaria-associated genes not only contributes in revealing the disease pathogenesis, but also facilitates discovering new targets for anti-malaria drugs. Methods In this study, we developed a network-based approach to predict malaria-associated genes. We constructed a cross-species network to integrate human-human, parasite-parasite and human-parasite protein interactions. Then we extended the random walk algorithm on this network, and used known malaria genes as the seeds to find novel candidate genes for malaria. Results We validated our algorithms using 77 known malaria genes: 14 human genes and 63 parasite genes were ranked averagely within top 2% and top 4%, respectively among human and parasite genomes. We also evaluated our method for predicting novel malaria genes using a set of 27 genes with literature supporting evidence. Our approach ranked 12 genes within top 1% and 24 genes within top 5%. In addition, we demonstrated that top-ranked candied genes were enriched for drug targets, and identified commonalities underlying top-ranked malaria genes through pathway analysis. In summary, the candidate malaria-associated genes predicted by our data-driven approach have the potential to guide genetics-based anti-malaria drug discovery. PMID:26099491

  19. Risks to California forests due to regional ozone pollution: A data base and ranking of forest sensitivity. Final report

    SciTech Connect

    Peterson, D.C.; Rowe, R.D.; Sueker, J.K.; Daly, C.; Moore, G.

    1989-02-01

    This project collected, calculated, and synthesized biological, economic, geographic, and ozone monitoring data into a gridded data base describing forested areas in California. Current and potential ozone risks to forest areas of California were then estimated. Over 50% of the forested areas in 12 California counties, five out of 19 national forests and 13 California watershed designation areas were found to be at high risk to ozone using a .045 ppm, 12-hour seasonal ozone standard.

  20. UK malaria treatment guidelines.

    PubMed

    Lalloo, David G; Shingadia, Delane; Pasvol, Geoffrey; Chiodini, Peter L; Whitty, Christopher J; Beeching, Nicholas J; Hill, David R; Warrell, David A; Bannister, Barbara A

    2007-02-01

    Malaria is the tropical disease most commonly imported into the UK, with 1500-2000 cases reported each year, and 10-20 deaths. Approximately three-quarters of reported malaria cases in the UK are caused by Plasmodium falciparum, which is capable of invading a high proportion of red blood cells and rapidly leading to severe or life-threatening multi-organ disease. Most non-falciparum malaria cases are caused by Plasmodium vivax; a few cases are caused by the other two species of Plasmodium: Plasmodium ovale or Plasmodium malariae. Mixed infections with more than 1 species of parasite can occur; they commonly involve P. falciparum with the attendant risks of severe malaria. Management of malaria depends on awareness of the diagnosis and on performing the correct diagnostic tests: the diagnosis cannot be excluded until 3 blood specimens have been examined by an experienced microscopist. There are no typical clinical features of malaria, even fever is not invariably present. The optimum diagnostic procedure is examination of thick and thin blood films by an expert to detect and speciate the malarial parasites; P. falciparum malaria can be diagnosed almost as accurately using rapid diagnostic tests (RDTs) which detect plasmodial antigens or enzymes, although RDTs for other Plasmodium species are not as reliable. The treatment of choice for non-falciparum malaria is a 3-day course of oral chloroquine, to which only a limited proportion of P. vivax strains have gained resistance. Dormant parasites (hypnozoites) persist in the liver after treatment of P. vivax or P. ovale infection: the only currently effective drug for eradication of hypnozoites is primaquine. This must be avoided or given with caution under expert supervision in patients with glucose-6-phosphate dehydrogenase deficiency (G6PD), in whom it may cause severe haemolysis. Uncomplicated P. falciparum malaria can be treated orally with quinine, atovaquone plus proguanil (Malarone) or co-artemether (Riamet

  1. Individual and Household Level Risk Factors Associated with Malaria in Nchelenge District, a Region with Perennial Transmission: A Serial Cross-Sectional Study from 2012 to 2015.

    PubMed

    Pinchoff, Jessie; Chaponda, Mike; Shields, Timothy M; Sichivula, James; Muleba, Mbanga; Mulenga, Modest; Kobayashi, Tamaki; Curriero, Frank C; Moss, William J

    2016-01-01

    The scale-up of malaria control interventions has resulted in substantial declines in transmission in some but not all regions of sub-Saharan Africa. Understanding factors associated with persistent malaria transmission despite control efforts may guide targeted interventions to high-risk areas and populations. Household malaria surveys were conducted in Nchelenge District, Luapula Province, in northern Zambia. Structures that appeared to be households were enumerated from a high-resolution satellite image and randomly sampled for enrollment. Households were enrolled into cross-sectional (single visit) or longitudinal (visits every other month) cohorts but analyses were restricted to cross-sectional visits and the first visit to longitudinal households. During study visits, a questionnaire was administered to adults and caretakers of children and a blood sample was collected for a malaria rapid diagnostic test (RDT) from all household residents. Characteristics associated with RDT positivity were analyzed using multi-level models. A total of 2,486 individuals residing within 742 households were enrolled between April 2012 and July 2015. Over this period, 51% of participants were RDT positive. Forty-three percent of all RDT positive individuals were between the ages of 5 and 17 years although this age group comprised only 30% of study participants. In a multivariable model, the odds being RDT positive were highest in 5-17 year olds and did not vary by season. Children 5-17 years of age had 8.83 higher odds of being RDT positive compared with those >18 years of age (95% CI: 6.13, 12.71); there was an interaction between age and report of symptoms, with an almost 50% increased odds of report of symptoms with decreasing age category (OR = 1.49; 95% CI 1.11, 2.00). Children and adolescents between the ages of 5 and 17 were at the highest risk of malaria infection throughout the year. School-based programs may be effective at targeting this high-risk group.

  2. Individual and Household Level Risk Factors Associated with Malaria in Nchelenge District, a Region with Perennial Transmission: A Serial Cross-Sectional Study from 2012 to 2015

    PubMed Central

    Pinchoff, Jessie; Chaponda, Mike; Shields, Timothy M.; Sichivula, James; Muleba, Mbanga; Mulenga, Modest; Kobayashi, Tamaki; Curriero, Frank C.; Moss, William J.

    2016-01-01

    Background The scale-up of malaria control interventions has resulted in substantial declines in transmission in some but not all regions of sub-Saharan Africa. Understanding factors associated with persistent malaria transmission despite control efforts may guide targeted interventions to high-risk areas and populations. Methods Household malaria surveys were conducted in Nchelenge District, Luapula Province, in northern Zambia. Structures that appeared to be households were enumerated from a high-resolution satellite image and randomly sampled for enrollment. Households were enrolled into cross-sectional (single visit) or longitudinal (visits every other month) cohorts but analyses were restricted to cross-sectional visits and the first visit to longitudinal households. During study visits, a questionnaire was administered to adults and caretakers of children and a blood sample was collected for a malaria rapid diagnostic test (RDT) from all household residents. Characteristics associated with RDT positivity were analyzed using multi-level models. Results A total of 2,486 individuals residing within 742 households were enrolled between April 2012 and July 2015. Over this period, 51% of participants were RDT positive. Forty-three percent of all RDT positive individuals were between the ages of 5 and 17 years although this age group comprised only 30% of study participants. In a multivariable model, the odds being RDT positive were highest in 5–17 year olds and did not vary by season. Children 5–17 years of age had 8.83 higher odds of being RDT positive compared with those >18 years of age (95% CI: 6.13, 12.71); there was an interaction between age and report of symptoms, with an almost 50% increased odds of report of symptoms with decreasing age category (OR = 1.49; 95% CI 1.11, 2.00). Conclusions Children and adolescents between the ages of 5 and 17 were at the highest risk of malaria infection throughout the year. School-based programs may be effective at

  3. A rank-based transcriptional signature for predicting relapse risk of stage II colorectal cancer identified with proper data sources

    PubMed Central

    Zhao, Wenyuan; Chen, Beibei; Guo, Xin; Wang, Ruiping; Chang, Zhiqiang; Dong, Yu; Song, Kai; Wang, Wen; Qi, Lishuang; Gu, Yunyan; Wang, Chenguang; Yang, Da; Guo, Zheng

    2016-01-01

    The irreproducibility problem seriously hinders the studies on transcriptional signatures for predicting relapse risk of early stage colorectal cancer (CRC) patients. Through reviewing recently published 34 literatures for the development of CRC prognostic signatures based on gene expression profiles, we revealed a surprising phenomenon that 33 of these studies analyzed CRC samples with and without adjuvant chemotherapy together in the training and/or validation datasets. This data misuse problem could be partially attributed to the unclear and incomplete data annotation in public data sources. Furthermore, all the signatures proposed by these studies were based on risk scores summarized from gene expression levels, which are sensitive to experimental batch effects and risk compositions of the samples analyzed together. To avoid the above-mentioned problems, we carefully selected three qualified large datasets to develop and validate a signature consisting of three pairs of genes. The within-sample relative expression orderings of these gene pairs could robustly predict relapse risk of stage II CRC samples assessed in different laboratories. The transcriptional and functional analyses provided clear evidence that the high risk patients predicted by the proposed signature represent patients with micro-metastases. PMID:26967049

  4. Is maternal education a social vaccine for childhood malaria infection? A cross-sectional study from war-torn Democratic Republic of Congo.

    PubMed

    Ma, Cary; Claude, Kasereka Masumbuko; Kibendelwa, Zacharie Tsongo; Brooks, Hannah; Zheng, Xiaonan; Hawkes, Michael

    2017-03-01

    In zones of violent conflict in the tropics, social disruption leads to elevated child mortality, of which malaria is the leading cause. Understanding the social determinants of malaria transmission may be helpful to optimize malaria control efforts. We conducted a cross-sectional study of healthy children aged 2 months to 5 years attending well-child and/or immunization visits in the Democratic Republic of Congo (DRC). Six hundred and forty-seven children were tested for malaria antigenemia by rapid diagnostic test and the accompanying parent or legal guardian simultaneously completed a survey questionnaire related to demographics, socioeconomic status, maternal education, as well as bednet use and recent febrile illness. We examined the associations between variables using multivariable logistic regression analysis, chi-squared statistic, Fisher's exact test, and Spearman's rank correlation, as appropriate. One hundred and twenty-three out of the 647 (19%) children in the study tested positive for malaria. Higher levels of maternal education were associated with a lower risk of malaria in their children. The prevalence of malaria in children of mothers with no education, primary school, and beyond primary was 41/138 (30%), 41/241 (17%), and 39/262 (15%), respectively (p = 0.001). In a multivariable logistic regression model adjusting for the effect of a child's age and study site, the following remained significant predictors of malaria antigenemia: maternal education, number of children under five per household, and HIV serostatus. Higher maternal education, through several putative causal pathways, was associated with lower malaria prevalence among children in the DRC. Our findings suggest that maternal education might be an effective 'social vaccine' against malaria in the DRC and globally.

  5. The Association between Nutritional Status and Malaria in Children from a Rural Community in the Amazonian Region: A Longitudinal Study

    PubMed Central

    Alexandre, Márcia Almeida Araújo; Benzecry, Silvana Gomes; Siqueira, Andre Machado; Vitor-Silva, Sheila; Melo, Gisely Cardoso; Monteiro, Wuelton Marcelo; Leite, Heitor Pons; Lacerda, Marcus Vinícius Guimarães; Alecrim, Maria das Graças Costa

    2015-01-01

    Background The relationship between malaria and undernutrition is controversial and complex. Synergistic associations between malnutrition and malaria morbidity and mortality have been suggested, as well as undernutrition being protective against infection, while other studies found no association. We sought to evaluate the relationship between the number of malaria episodes and nutritional statuses in a cohort of children below 15 years of age living in a rural community in the Brazilian Amazon. Methodology/Principal Findings Following a baseline survey of clinical, malaria and nutritional assessment including anthropometry measurements and hemoglobin concentration, 202 children ranging from 1 month to 14 years of age were followed for one year through passive case detection for malaria episodes. After follow-up, all children were assessed again in order to detect changes in nutritional indicators associated with malaria infection. We also examined the risk of presenting malaria episodes during follow-up according to presence of stunting at baseline. Children who suffered malaria episodes during follow-up presented worse anthropometric parameters values during this period. The main change was a reduction of the linear growth velocity, associated with both the number of episodes and how close the last or only malaria episode and the second anthropometric assessment were. Changes were also observed for indices associated with chronic changes, such as weight-for-age and BMI-for-age, which conversely, were more frequently observed in children with the last or only episode occurring between 6 and 12 months preceding the second nutritional assessment survey. Children with inadequate height-for-age at baseline (Z-score < -2) presented lower risk of suffering malaria episodes during follow-up as assessed by both the log-rank test (p =0.057) and the multivariable Cox-proportional hazards regression (Hazard Ratio = 0.31, 95%CI [0.10; 0.99] p=0.049). Conclusions Malaria was

  6. Cord blood IgG and the risk of severe Plasmodium falciparum malaria in the first year of life.

    PubMed

    Murungi, Linda M; Sondén, Klara; Odera, Dennis; Oduor, Loureen B; Guleid, Fatuma; Nkumama, Irene N; Otiende, Mark; Kangoye, David T; Fegan, Greg; Färnert, Anna; Marsh, Kevin; Osier, Faith H A

    2017-02-01

    Young infants are less susceptible to severe episodes of malaria but the targets and mechanisms of protection are not clear. Cord blood antibodies may play an important role in mediating protection but many studies have examined their association with the outcome of infection or non-severe malaria. Here, we investigated whether cord blood IgG to Plasmodium falciparum merozoite antigens and antibody-mediated effector functions were associated with reduced odds of developing severe malaria at different time points during the first year of life. We conducted a case-control study of well-defined severe falciparum malaria nested within a longitudinal birth cohort of Kenyan children. We measured cord blood total IgG levels against five recombinant merozoite antigens and antibody function in the growth inhibition activity and neutrophil antibody-dependent respiratory burst assays. We also assessed the decay of maternal antibodies during the first 6months of life. The mean antibody half-life range was 2.51months (95% confidence interval (CI): 2.19-2.92) to 4.91months (95% CI: 4.47-6.07). The rate of decline of maternal antibodies was inversely proportional to the starting concentration. The functional assay of antibody-dependent respiratory burst activity predicted significantly reduced odds of developing severe malaria during the first 6months of life (Odds ratio (OR) 0.07, 95% CI: 0.007-0.74, P=0.007). Identification of the targets of antibodies mediating antibody-dependent respiratory burst activity could contribute to the development of malaria vaccines that protect against severe episodes of malaria in early infancy. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Malaria in patients with sickle cell anemia: burden, risk factors, and outcome at the outpatient clinic and during hospitalization

    PubMed Central

    Makani, Julie; Komba, Albert N.; Cox, Sharon E.; Oruo, Julie; Mwamtemi, Khadija; Kitundu, Jesse; Magesa, Pius; Rwezaula, Stella; Meda, Elineema; Mgaya, Josephine; Pallangyo, Kisali; Okiro, Emelda; Muturi, David; Newton, Charles R.; Fegan, Gregory; Marsh, Kevin; Williams, Thomas N.

    2010-01-01

    Approximately 280 000 children are born with sickle cell anemia (SCA) in Africa annually, yet few survive beyond childhood. Falciparum malaria is considered a significant cause of this mortality. We conducted a 5-year prospective surveillance study for malaria parasitemia, clinical malaria, and severe malarial anemia (SMA) in Dar-es-Salaam, Tanzania, between 2004 and 2009. We recorded 10 491 visits to the outpatient clinic among 1808 patients with SCA and 773 visits among 679 patients without SCA. Similarly, we recorded 691 hospital admissions among 497 patients with SCA and 2017 in patients without SCA. Overall, the prevalence of parasitemia was lower in patients with SCA than in patients without SCA both at clinic (0.7% vs 1.6%; OR, 0.53; 95% CI, 0.32-0.86; P = .008) and during hospitalization (3.0% vs 5.6%; OR, 0.46; 95% CI, 0.25-0.94; P = .01). Furthermore, patients with SCA had higher rates of malaria during hospitalization than at clinic, the ORs being 4.29 (95% CI, 2.63-7.01; P < .001) for parasitemia, 17.66 (95% CI, 5.92-52.71; P < .001) for clinical malaria, and 21.11 (95% CI, 8.46-52.67; P < .001) for SMA. Although malaria was rare among patients with SCA, parasitemia during hospitalization was associated with both severe anemia and death. Effective treatment for malaria during severe illness episodes and further studies to determine the role chemoprophylaxis are required. PMID:19901265

  8. Malaria Treatment (United States)

    MedlinePlus

    ... a CDC Malaria Branch clinician. malaria@cdc.gov Malaria Treatment (United States) Recommend on Facebook Tweet Share Compartir Treatment of Malaria: Guidelines For Clinicians (United States) Download PDF version ...

  9. A description of malaria-related knowledge, perceptions, and practices in the Artibonite Valley of Haiti: implications for malaria control.

    PubMed

    Keating, Joseph; Eisele, Thomas P; Bennett, Adam; Johnson, Dawn; Macintyre, Kate

    2008-02-01

    A two-stage cluster survey (n = 200 households) was conducted in the Artibonite Valley of Haiti during the high malaria transmission season in November-December 2006. Knowledge, perceptions, and practices related to malaria were obtained from household representatives using a standardized questionnaire. Blood drops were obtained on filter paper from all household members more than one month of age (n = 714). Determinants of malaria infections and correct malaria-related knowledge were assessed using logistic regression. Respondents in households with more assets were significantly more likely than those in households with fewer assets to have correct malaria-related knowledge. Respondents from households with at least one malaria infection were less likely to have correct malaria-related knowledge. Older children (5-9 years of age) were shown to be at increased risk of malaria infection. Results suggest malaria control in Haiti should focus on enhanced surveillance and case management, with expanded information campaigns about malaria prevention and treatment options.

  10. 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.

  11. Principal component analysis of socioeconomic factors and their association with malaria and arbovirus risk in Tanzania: a sensitivity analysis.

    PubMed

    Homenauth, Esha; Kajeguka, Debora; Kulkarni, Manisha A

    2017-08-19

    Principal component analysis (PCA) is frequently adopted for creating socioeconomic proxies in order to investigate the independent effects of wealth on disease status. The guidelines and methods for the creation of these proxies are well described and validated. The Demographic and Health Survey, World Health Survey and the Living Standards Measurement Survey are examples of large data sets that use PCA to create wealth indices particularly in low and middle-income countries (LMIC), where quantifying wealth-disease associations is problematic due to the unavailability of reliable income and expenditure data. However, the application of this method to smaller survey data sets, especially in rural LMIC settings, is less rigorously studied.In this paper, we aimed to highlight some of these issues by investigating the association of derived wealth indices using PCA on risk of vector-borne disease infection in Tanzania focusing on malaria and key arboviruses (ie, dengue and chikungunya). We demonstrated that indices consisting of subsets of socioeconomic indicators provided the least methodologically flawed representations of household wealth compared with an index that combined all socioeconomic variables. These results suggest that the choice of the socioeconomic indicators included in a wealth proxy can influence the relative position of households in the overall wealth hierarchy, and subsequently the strength of disease associations. This can, therefore, influence future resource planning activities and should be considered among investigators who use a PCA-derived wealth index based on community-level survey data to influence programme or policy decisions in rural LMIC settings. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  12. The Pattern of Variation between Diarrhea and Malaria Coexistence with Corresponding Risk Factors in, Chikhwawa, Malawi: A Bivariate Multilevel Analysis.

    PubMed

    Masangwi, Salule; Ferguson, Neil; Grimason, Anthony; Morse, Tracy; Kazembe, Lawrence

    2015-07-21

    Developing countries face a huge burden of infectious diseases, a number of which co-exist. This paper estimates the pattern and variation of malaria and diarrhea coexistence in Chikhwawa, a district in Southern Malawi using bivariate multilevel modelling with Bayesian estimation. A probit link was employed to examine hierarchically built data from a survey of individuals (n = 6,727) nested within households (n = 1,380) nested within communities (n = 33). Results show significant malaria [σ²μ₁=0.901 (95% CI:0.746,1.056)] and diarrhea [σ²μ₂=1.009 (95% CI:0.860,1.158)] variations with a strong correlation between them [r(¹,²)μ=0.565] at household level. There are significant malaria [σ²ν₁=0.053 (95% CI: 0.018,0.088)] and diarrhea [σ²ν₂=0.099(95% CI : 0.030,0.168) ] variations at community level but with a small correlation [r(¹,²) ν=0.124] between them. There is also significant correlation between malaria and diarrhea at individual level [ r(¹,²) e=0.241]. These results suggest a close association between reported malaria-like illness and diarrheal illness especially at household and individual levels in Southern Malawi.

  13. 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

  14. WHO Expert Committee on Malaria. Seventeenth report.

    PubMed

    1979-01-01

    This publication consists of guidelines to assist health administrators and planners in planning, implementing, and evaluating malaria control programs that reflect the reorientation of the World Health Organization malaria control strategy endorsed by the World Health Assembly. The report stresses approaches to malaria control, describing the recent resurgence of malaria and present constraints on malaria control; prerequisites for implementation of the revised antimalaria strategy; objectives of a malaria control program; factors affecting planning of control programs including epidemiological factors related to the environment, man, the vector, and the parasite; socioeconomic factors; and the use of antimalaria measures in 4 different situations for reduction and prevention of mortality due to malaria, reduction and prevention of mortality and morbidity particularly in high risk groups, reduction of prevalence and endemicity of malaria, or countrywide malaria control aimed ultimately at eradication; program implementation, including definition of targets, interrelationship of the malaria services, general health services, and community, and program implementation in relation to each of the 4 tactical variants; and general principles, operational and epidemiological criteria, and socioeconomic indicators for program evaluation. Factors determining malaria epidemics, outbreaks of malaria during eradication or control campaigns, forecasting and detection of malaria epidemics, and control of epidemics are then discussed. Training in malaria control and advances in antimalaria measures including drugs, immunological methods, antimosquito measures, and biological and genetic approaches to vector control and their potential value are assessed. Program coordination between countries and at regional and global levels and data collection and dissemination for international surveillance are discussed. A series of recommendations is offered for various aspects of malaria

  15. Malaria vaccine.

    PubMed

    1994-05-01

    Some have argued that the vaccine against malaria developed by Manuel Pattaroyo, a Colombian scientist, is being tested prematurely in humans and that it is unlikely to be successful. While the Pattaroyo vaccine has been shown to confer protection against the relatively mild malaria found in Colombia, doubts exist over whether it will be effective in Africa. Encouraging first results, however, are emerging from field tests in Tanzania. The vaccine triggered a strong new immune response, even in individuals previously exposed to malaria. Additional steps must be taken to establish its impact upon mortality and morbidity. Five major trials are underway around the world. The creator estimates that the first ever effective malaria vaccine could be available for widespread use within five years and he has no intention of securing a patent for the discovery. In another development, malaria specialists from 35 African countries convened at an international workshop in Zimbabwe to compare notes. Participants disparaged financial outlays for the fight against malaria equivalent to 2% of total AIDS funding as insufficient; noted intercountry differences in prevention, diagnosis, and treatment; and found information exchange between anglophone and francophone doctors to be generally poor.

  16. Integrating Household Water Treatment, Hand Washing, and Insecticide-Treated Bed Nets into Pediatric HIV Care in Mombasa, Kenya: Impact on Diarrhea and Malaria Risk.

    PubMed

    Sugar, Naomi R; Schilling, Katharine A; Kim, Sunkyung; Ahmed, Aabid; Muyanga, Dennis Ngui; Sivapalasingam, Sumathi; Quick, Robert

    2017-08-04

    In developing countries, HIV-infected children are at higher risk for morbidity and mortality from opportunistic infections than HIV-uninfected children. To address this problem, the Healthy Living Initiative (HLI) in Mombasa, Kenya distributed basic care packages (BCPs) containing improved water storage vessels, water treatment solution, soap, and insecticide-treated bednets (ITNs) to prevent diarrhea and malaria in children, and had community health workers (CHWs) make bimonthly home visits to encourage adherence with HLI interventions and antiretroviral medicine use. To evaluate HLI, we enrolled 500 HIV-infected children from Bomu Hospital. In the implementation phase, from February-August 2011, we conducted surveys of caregivers, then provided free BCPs. In the evaluation phase, from September 2011-August 2012, CHWs recorded observations of BCP use during home visits. We abstracted hospital data to compare diarrhea and malaria episodes, and pharmacy data on antiretrovirals (ARVs) dispensed, between the 12-month pre-implementation baseline phase (February 2010-January 2011) and the evaluation phase. The retention rate of children in HLI was 78.4%. In a multivariable logistic regression model adjusting for demographic characteristics, number of CHW home visits, distance to clinic, orphan status, and number of ARVs dispensed, children in HLI had 71 % lower risk of diarrhea (relative risk [RR] 0.29, p<0.001) and 87% lower risk of malaria (RR 0.13, p=0.001) during the evaluation phase than the baseline phase; there was no independent association between ARV use and illness. HIV-infected children in HLI were less likely to experience diarrhea and malaria during the evaluation phase than the baseline phase.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in

  17. Imported malaria in Kuwait.

    PubMed

    Hira, P R; Behbehani, K; Al-Kandari, S

    1985-01-01

    The number of imported malaria cases in Kuwait rose from 87 in 1980 to 504 in 1983, an increase of 579%. The continued resurgence of malaria in endemic zones, improved diagnostic techniques and a heightened awareness of imported malaria have contributed to the increase in the number of microscopically proved cases. Thick blood films fixed in acetone and stained in Giemsa proved a rapid method of diagnosis; species identification on the basis of a thin film on the same slide was performed with ease. Malaria was acquired in 38 countries. Most patients were young male adults. Most of the cases were due to Plasmodium vivax originating from India, although an increasing number of P. falciparum cases are also now being diagnosed from there. P. falciparum infections were evenly distributed throughout the year and most cases presented within 14 days of their arrival in the country. The highest number of P. vivax cases were diagnosed between May and October, when heat stress might have been a factor in precipitating a clinical attack of an infection previously acquired in the endemic zone. Attention is drawn to the importance of delayed attacks of P. vivax and, in semi-immunes, of P. falciparum. The time interval involved in establishing a history of "recent" travel in clinically suspected cases of malaria needs to be more clearly defined in each geographical area. Cases of induced malaria due to transfusion, accidental and congenital infections were identified. The fatality rate due to P. falciparum infections was low. In terms of the risk of renewed transmission, Kuwait may be considered a vulnerable area.

  18. Elevated dry-season malaria prevalence associated with fine-scale spatial patterns of environmental risk: a case-control study of children in rural Malawi.

    PubMed

    Townes, Lindsay R; Mwandama, Dyson; Mathanga, Don P; Wilson, Mark L

    2013-11-11

    Understanding the role of local environmental risk factors for malaria in holo-endemic, poverty-stricken settings will be critical to more effectively implement- interventions aimed at eventual elimination. Household-level environmental drivers of malaria risk during the dry season were investigated in rural southern Malawi among children < five years old in two neighbouring rural Traditional Authority (TA) regions dominated by small-scale agriculture. Ten villages were randomly selected from TA Sitola (n = 6) and Nsamala (n = 4). Within each village, during June to August 2011, a census was conducted of all households with children under-five and recorded their locations with a geographic position system (GPS) device. At each participating house, a nurse administered a malaria rapid diagnostic test (RDT) to children under five years of age, and a questionnaire to parents. Environmental data were collected for each house, including land cover within 50-m radius. Variables found to be significantly associated with P. falciparum infection status in bivariate analysis were included in generalized linear models, including multivariate logistic regression (MLR) and multi-level multivariate logistic regression (MLLR). Spatial clustering of RDT status, environmental factors, and Pearson residuals from MLR and MLLR were analysed using the Getis-Ord Gi* statistic. Of 390 children enrolled from six villages in Sitola (n = 162) and four villages in Nsamala (n = 228), 45.6% tested positive (n = 178) for Plasmodium infection by RDT. The MLLR modelled the statistical relationship of Plasmodium positives and household proximity to agriculture (<25-m radius), controlling for the child sex and age (in months), bed net ownership, elevation, and random effects intercepts for village and TA-level unmeasured factors. After controlling for area affects in MLLR, proximity to active agriculture remained a significant predictor of positive RDT result (OR 2.80, 95% CI 1.41-5.55). Mapping of

  19. Chronic dietary risk characterization for pesticide residues: a ranking and scoring method integrating agricultural uses and food contamination data.

    PubMed

    Nougadère, Alexandre; Reninger, Jean-Cédric; Volatier, Jean-Luc; Leblanc, Jean-Charles

    2011-07-01

    A method has been developed to identify pesticide residues and foodstuffs for inclusion in national monitoring programs with different priority levels. It combines two chronic dietary intake indicators: ATMDI based on maximum residue levels and agricultural uses, and EDI on food contamination data. The mean and 95th percentile of exposure were calculated for 490 substances using individual and national consumption data. The results show that mean ATMDI exceeds the acceptable daily intake (ADI) for 10% of the pesticides, and the mean upper-bound EDI is above the ADI for 1.8% of substances. A seven-level risk scale is presented for substances already analyzed in food in France and substances not currently sought. Of 336 substances analyzed, 70 pesticides of concern (levels 2-5) should be particularly monitored, 22 of which are priority pesticides (levels 4 and 5). Of 154 substances not sought, 36 pesticides of concern (levels 2-4) should be included in monitoring programs, including 8 priority pesticides (level 4). In order to refine exposure assessment, analytical improvements and developments are needed to lower the analytical limits for priority pesticide/commodity combinations. Developed nationally, this method could be applied at different geographic scales.

  20. Use of Medicare claims to rank hospitals by surgical site infection risk following coronary artery bypass graft surgery.

    PubMed

    Huang, Susan S; Placzek, Hilary; Livingston, James; Ma, Allen; Onufrak, Fallon; Lankiewicz, Julie; Kleinman, Ken; Bratzler, Dale; Olsen, Margaret A; Lyles, Rosie; Khan, Yosef; Wright, Paula; Yokoe, Deborah S; Fraser, Victoria J; Weinstein, Robert A; Stevenson, Kurt; Hooper, David; Vostok, Johanna; Datta, Rupak; Nsa, Wato; Platt, Richard

    2011-08-01

    To evaluate whether longitudinal insurer claims data allow reliable identification of elevated hospital surgical site infection (SSI) rates. We conducted a retrospective cohort study of Medicare beneficiaries who underwent coronary artery bypass grafting (CABG) in US hospitals performing at least 80 procedures in 2005. Hospitals were assigned to deciles by using case mix-adjusted probabilities of having an SSI-related inpatient or outpatient claim code within 60 days of surgery. We then reviewed medical records of randomly selected patients to assess whether chart-confirmed SSI risk was higher in hospitals in the worst deciles compared with the best deciles. Fee-for-service Medicare beneficiaries who underwent CABG in these hospitals in 2005. We evaluated 114,673 patients who underwent CABG in 671 hospitals. In the best decile, 7.8% (958/12,307) of patients had an SSI-related code, compared with 24.8% (2,747/11,068) in the worst decile ([Formula: see text]). Medical record review confirmed SSI in 40% (388/980) of those with SSI-related codes. In the best decile, the chart-confirmed annual SSI rate was 3.2%, compared with 9.4% in the worst decile, with an adjusted odds ratio of SSI of 2.7 (confidence interval, 2.2-3.3; [Formula: see text]) for CABG performed in a worst-decile hospital compared with a best-decile hospital. Claims data can identify groups of hospitals with unusually high or low post-CABG SSI rates. Assessment of claims is more reproducible and efficient than current surveillance methods. This example of secondary use of routinely recorded electronic health information to assess quality of care can identify hospitals that may benefit from prevention programs.

  1. World Health Organization ranking of antimicrobials according to their importance in human medicine: A critical step for developing risk management strategies for the use of antimicrobials in food production animals.

    PubMed

    Collignon, Peter; Powers, John H; Chiller, Tom M; Aidara-Kane, Awa; Aarestrup, Frank M

    2009-07-01

    The use of antimicrobials in food animals creates an important source of antimicrobial-resistant bacteria that can spread to humans through the food supply. Improved management of the use of antimicrobials in food animals, particularly reducing the usage of those that are "critically important" for human medicine, is an important step toward preserving the benefits of antimicrobials for people. The World Health Organization has developed and applied criteria to rank antimicrobials according to their relative importance in human medicine. Clinicians, regulatory agencies, policy makers, and other stakeholders can use this ranking when developing risk management strategies for the use of antimicrobials in food production animals. The ranking allows stakeholders to focus risk management efforts on drugs used in food animals that are the most important to human medicine and, thus, need to be addressed most urgently, such as fluoroquinolones, macrolides, and third- and fourth-generation cephalosporins.

  2. Risk factors for Plasmodium falciparum and Plasmodium vivax gametocyte carriage in Papua New Guinean children with uncomplicated malaria.

    PubMed

    Karl, Stephan; Laman, Moses; Moore, Brioni R; Benjamin, John M; Salib, Mary; Lorry, Lina; Maripal, Samuel; Siba, Peter; Robinson, Leanne J; Mueller, Ivo; Davis, Timothy M E

    2016-08-01

    There are limited data on gametocytaemia risk factors before/after treatment with artemisinin combination therapy in children from areas with transmission of multiple Plasmodium species. We utilised data from a randomised trial comparing artemether-lumefantrine (AL) and artemisinin-naphthoquine (AN) in 230 Papua New Guinean children aged 0.5-5 years with uncomplicated malaria in whom determinants of gametocytaemia by light microscopy were assessed at baseline using logistic regression and during follow-up using multilevel mixed effects modelling. Seventy-four (32%) and 18 (8%) children presented with P. falciparum and P. vivax gametocytaemia, respectively. Baseline P. falciparum gametocytaemia was associated with Hackett spleen grade 1 (odds ratio (95% CI) 4.01 (1.60-10.05) vs grade 0; P<0.001) and haemoglobin (0.95 (0.92-0.97) per 1g/L increase; P<0.001), and P. falciparum asexual parasitaemia in slide-positive cases (0.36 (0.19-0.68) for a 10-fold increase; P=0.002). Baseline P. vivax gametocytaemia was associated with Hackett grade 2 (12.66 (1.31-122.56); P=0.028), mixed P. falciparum/vivax infection (0.16 (0.03-1.00); P=0.050), P. vivax asexual parasitaemia (5.68 (0.98-33.04); P=0.053) and haemoglobin (0.94 (0.88-1.00); P=0.056). For post-treatment P. falciparum gametocytaemia, independent predictors were AN vs AL treatment (4.09 (1.43-11.65)), haemoglobin (0.95 (0.93-0.97)), presence/absence of P. falciparum asexual forms (3.40 (1.66-0.68)) and day post-treatment (0.086 (0.82-0.90)) (P<0.001). Post-treatment P. vivax gametocytaemia was predicted by presence of P. vivax asexual forms (596 (12-28,433); P<0.001). Consistent with slow P. falciparum gametocyte maturation, low haemoglobin, low asexual parasite density and higher spleen grading, markers of increased prior infection exposure/immunity, were strong associates of pre-treatment gametocyte positivity. The persistent inverse association between P. falciparum gametocytaemia and haemoglobin during follow

  3. Mapping the risk of anaemia in preschool-age children: the contribution of malnutrition, malaria, and helminth infections in West Africa.

    PubMed

    Magalhães, Ricardo J Soares; Clements, Archie C A

    2011-06-01

    Childhood anaemia is considered a severe public health problem in most countries of sub-Saharan Africa. We investigated the geographical distribution of prevalence of anaemia and mean haemoglobin concentration (Hb) in children aged 1-4 y (preschool children) in West Africa. The aim was to estimate the geographical risk profile of anaemia accounting for malnutrition, malaria, and helminth infections, the risk of anaemia attributable to these factors, and the number of anaemia cases in preschool children for 2011. National cross-sectional household-based demographic health surveys were conducted in 7,147 children aged 1-4 y in Burkina Faso, Ghana, and Mali in 2003-2006. Bayesian geostatistical models were developed to predict the geographical distribution of mean Hb and anaemia risk, adjusting for the nutritional status of preschool children, the location of their residence, predicted Plasmodium falciparum parasite rate in the 2- to 10-y age group (Pf PR(2-10)), and predicted prevalence of Schistosoma haematobium and hookworm infections. In the four countries, prevalence of mild, moderate, and severe anaemia was 21%, 66%, and 13% in Burkina Faso; 28%, 65%, and 7% in Ghana, and 26%, 62%, and 12% in Mali. The mean Hb was lowest in Burkina Faso (89 g/l), in males (93 g/l), and for children 1-2 y (88 g/l). In West Africa, severe malnutrition, Pf PR(2-10), and biological synergisms between S. haematobium and hookworm infections were significantly associated with anaemia risk; an estimated 36.8%, 14.9%, 3.7%, 4.2%, and 0.9% of anaemia cases could be averted by treating malnutrition, malaria, S. haematobium infections, hookworm infections, and S. haematobium/hookworm coinfections, respectively. A large spatial cluster of low mean Hb (<80 g/l) and maximal risk of anaemia (>95%) was predicted for an area shared by Burkina Faso and Mali. We estimate that in 2011, approximately 6.7 million children aged 1-4 y are anaemic in the three study countries. By mapping the distribution

  4. Mapping the Risk of Anaemia in Preschool-Age Children: The Contribution of Malnutrition, Malaria, and Helminth Infections in West Africa

    PubMed Central

    Soares Magalhães, Ricardo J.; Clements, Archie C. A.

    2011-01-01

    Background Childhood anaemia is considered a severe public health problem in most countries of sub-Saharan Africa. We investigated the geographical distribution of prevalence of anaemia and mean haemoglobin concentration (Hb) in children aged 1–4 y (preschool children) in West Africa. The aim was to estimate the geographical risk profile of anaemia accounting for malnutrition, malaria, and helminth infections, the risk of anaemia attributable to these factors, and the number of anaemia cases in preschool children for 2011. Methods and Findings National cross-sectional household-based demographic health surveys were conducted in 7,147 children aged 1–4 y in Burkina Faso, Ghana, and Mali in 2003–2006. Bayesian geostatistical models were developed to predict the geographical distribution of mean Hb and anaemia risk, adjusting for the nutritional status of preschool children, the location of their residence, predicted Plasmodium falciparum parasite rate in the 2- to 10-y age group (Pf PR2–10), and predicted prevalence of Schistosoma haematobium and hookworm infections. In the four countries, prevalence of mild, moderate, and severe anaemia was 21%, 66%, and 13% in Burkina Faso; 28%, 65%, and 7% in Ghana, and 26%, 62%, and 12% in Mali. The mean Hb was lowest in Burkina Faso (89 g/l), in males (93 g/l), and for children 1–2 y (88 g/l). In West Africa, severe malnutrition, Pf PR2–10, and biological synergisms between S. haematobium and hookworm infections were significantly associated with anaemia risk; an estimated 36.8%, 14.9%, 3.7%, 4.2%, and 0.9% of anaemia cases could be averted by treating malnutrition, malaria, S. haematobium infections, hookworm infections, and S. haematobium/hookworm coinfections, respectively. A large spatial cluster of low mean Hb (<80 g/l) and maximal risk of anaemia (>95%) was predicted for an area shared by Burkina Faso and Mali. We estimate that in 2011, approximately 6.7 million children aged 1–4 y are anaemic in the three

  5. Using publicly available information to create exposure and risk-based ranking of chemicals used in the workplace and consumer products.

    PubMed

    Jayjock, Michael A; Chaisson, Christine F; Franklin, Claire A; Arnold, Susan; Price, Paul S

    2009-07-01

    Mandates that require the estimation of exposure and human health risk posed by large numbers of chemicals present regulatory managers with a significant challenge. Although these issues have been around for some time, the estimation of human exposure to chemicals from use of products in the workplace and by the consumer has been generally hindered by the lack of good tools. Logically and in the interest of cost-effective resource allocation and regulation one would typically and naturally first attempt to rank-order or prioritize the chemicals according to the human exposure potential that each might pose. We have developed an approach and systematic modeling construct that accomplishes this critical task by providing a quantitative estimate of human exposure for as many as several hundred chemicals initially; however, it could ultimately do this for any number of regulated chemicals starting only with the identity (Chemical Abstract Service number) for each chemical under consideration. These exposure estimates can then be readily linked to toxicological benchmarks for each item to estimate and rank the human health risk for the chemicals under consideration in a "worst things first" listing. This modeling construct, entitled Complex Exposure Tool (ComET) was developed by The LifeLine Group as a proof of concept under the sponsorship of Health Canada. ComET considers multiple routes of exposure, multiple subpopulations and different possible durations of exposure. A beta-version of ComET was issued and demonstrated in which users can change the assumptions in the model and see the impacts of these changes and the quality of information as they relate to the predicted exposure potential. We have advanced the operational elements of ComET into a tool entitled the Chemical Exposure Priority Setting Tool (CEPST) designed to provide quantitative estimation of the exposure potential of large groups of chemicals with little data and possibly multiple exposure scenarios

  6. Malaria Prophylaxis: A Comprehensive Review

    PubMed Central

    Castelli, Francesco; Odolini, Silvia; Autino, Beatrice; Foca, Emanuele; Russo, Rosario

    2010-01-01

    The flow of international travellers to and from malaria-endemic areas, especially Africa, has increased in recent years. Apart from the very high morbidity and mortality burden imposed on malaria-endemic areas, imported malaria is the main cause of fever possibly causing severe disease and death in travellers coming from tropical and subtropical areas, particularly Sub-Saharan Africa. The importance of behavioural preventive measures (bed nets, repellents, etc.), adequate chemoprophylaxis and, in selected circumstances, stand-by emergency treatment may not be overemphasized. However, no prophylactic regimen may offer complete protection. Expert advice is needed to tailor prophylactic advice according to traveller (age, baseline clinical conditions, etc.) and travel (destination, season, etc.) characteristics in order to reduce malaria risk.

  7. Malaria and global change: Insights, uncertainties and possible surprises

    SciTech Connect

    Martin, P.H.; Steel, A.

    1996-12-31

    Malaria may change with global change. Indeed, global change may affect malaria risk and malaria epidemiology. Malaria risk may change in response to a greenhouse warming; malaria epidemiology, in response to the social, economic, and political developments which a greenhouse warming may trigger. To date, malaria receptivity and epidemiology futures have been explored within the context of equilibrium studies. Equilibrium studies of climate change postulate an equilibrium present climate (the starting point) and a doubled-carbon dioxide climate (the end point), simulate conditions in both instances, and compare the two. What happens while climate changes, i.e., between the starting point and the end point, is ignored. The present paper focuses on malaria receptivity and addresses what equilibrium studies miss, namely transient malaria dynamics.

  8. Ethical aspects of malaria control and research.

    PubMed

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

    2015-12-22

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

  9. Reduced Risk of Plasmodium vivax Malaria in Papua New Guinean Children with Southeast Asian Ovalocytosis in Two Cohorts and a Case-Control Study

    PubMed Central

    Manning, Laurens; Rarau, Patricia; Laman, Moses; Senn, Nicolas; Grimberg, Brian T.; Tavul, Livingstone; Stanisic, Danielle I.; Robinson, Leanne J.; Aponte, John J.; Dabod, Elijah; Reeder, John C.; Siba, Peter; Zimmerman, Peter A.; Davis, Timothy M. E.; King, Christopher L.; Michon, Pascal; Mueller, Ivo

    2012-01-01

    Background The erythrocyte polymorphism, Southeast Asian ovalocytosis (SAO) (which results from a 27-base pair deletion in the erythrocyte band 3 gene, SLC4A1Δ27) protects against cerebral malaria caused by Plasmodium falciparum; however, it is unknown whether this polymorphism also protects against P. vivax infection and disease. Methods and Findings The association between SAO and P. vivax infection was examined through genotyping of 1,975 children enrolled in three independent epidemiological studies conducted in the Madang area of Papua New Guinea. SAO was associated with a statistically significant 46% reduction in the incidence of clinical P. vivax episodes (adjusted incidence rate ratio [IRR] = 0.54, 95% CI 0.40–0.72, p<0.0001) in a cohort of infants aged 3–21 months and a significant 52% reduction in P. vivax (blood-stage) reinfection diagnosed by PCR (95% CI 22–71, p = 0.003) and 55% by light microscopy (95% CI 13–77, p = 0.014), respectively, in a cohort of children aged 5–14 years. SAO was also associated with a reduction in risk of P. vivax parasitaemia in children 3–21 months (1,111/µl versus 636/µl, p = 0.011) and prevalence of P. vivax infections in children 15–21 months (odds ratio [OR] = 0.39, 95% CI 0.23–0.67, p = 0.001). In a case-control study of children aged 0.5–10 years, no child with SAO was found among 27 cases with severe P. vivax or mixed P. falciparum/P. vivax malaria (OR = 0, 95% CI 0–1.56, p = 0.11). SAO was associated with protection against severe P. falciparum malaria (OR = 0.38, 95% CI 0.15–0.87, p = 0.014) but no effect was seen on either the risk of acquiring blood-stage infections or uncomplicated episodes with P. falciparum. Although Duffy antigen receptor expression and function were not affected on SAO erythrocytes compared to non-SAO children, high level (>90% binding inhibition) P. vivax Duffy binding protein–specific binding inhibitory antibodies were

  10. Rank 4 Premodular Categories

    SciTech Connect

    Bruillard, Paul J.; Galindo, Cesar; Ng, Siu Hung; Plavnik, Julia; Rowell, Eric; Wang, Zhenghan

    2016-09-01

    We consider the classification problem for rank 4 premodular categories. We uncover a formula for the 2nd Frobenius-Schur indicator of a premodular category is determined and the classification of rank 4 premodular categories (up to Grothendieck equivalence) is completed. In the appendix we show rank finiteness for premodular categories.

  11. A Reduced Risk of Infection with Plasmodium vivax and Clinical Protection against Malaria Are Associated with Antibodies against the N Terminus but Not the C Terminus of Merozoite Surface Protein 1†

    PubMed Central

    Nogueira, Paulo Afonso; Piovesan Alves, Fabiana; Fernandez-Becerra, Carmen; Pein, Oliver; Rodrigues Santos, Neida; Pereira da Silva, Luiz Hildebrando; Plessman Camargo, Erney; del Portillo, Hernando A.

    2006-01-01

    Progress towards the development of a malaria vaccine against Plasmodium vivax, the most widely distributed human malaria parasite, will require a better understanding of the immune responses that confer clinical protection to patients in regions where malaria is endemic. The occurrence of clinical protection in P. vivax malaria in Brazil was first reported among residents of the riverine community of Portuchuelo, in Rondônia, western Amazon. We thus analyzed immune sera from this same human population to determine if naturally acquired humoral immune responses against the merozoite surface protein 1 of P. vivax, PvMSP1, could be associated with reduced risk of infection and/or clinical protection. Our results demonstrated that this association could be established with anti-PvMSP1 antibodies predominantly of the immunoglobulin G3 subclass directed against the N terminus but not against the C terminus, in spite of the latter being more immunogenic and capable of natural boosting. This is the first report of a prospective study of P. vivax malaria demonstrating an association of reduced risk of infection and clinical protection with antibodies against an antigen of this parasite. PMID:16622209

  12. Defining the Global Spatial Limits of Malaria Transmission in 2005

    PubMed Central

    Guerra, C.A.; Snow, R.W.; Hay, S.I.

    2011-01-01

    There is no accurate contemporary global map of the distribution of malaria. We show how guidelines formulated to advise travellers on appropriate chemoprophylaxis for areas of reported Plasmodium falciparum and Plasmodium vivax malaria risk can be used to generate crude spatial limits. We first review and amalgamate information on these guidelines to define malaria risk at national and sub-national administrative boundary levels globally. We then adopt an iterative approach to reduce these extents by applying a series of biological limits imposed by altitude, climate and population density to malaria transmission, specific to the local dominant vector species. Global areas of, and population at risk from, P. falciparum and often-neglected P. vivax malaria are presented for 2005 for all malaria endemic countries. These results reveal that more than 3 billion people were at risk of malaria in 2005. PMID:16647970

  13. Shrinking the malaria map: progress and prospects

    PubMed Central

    Feachem, Richard GA; Phillips, Allison A; Hwang, Jimee; Cotter, Chris; Wielgosz, Benjamin; Greenwood, Brian M; Sabot, Oliver; Rodriguez, Mario Henry; Abeyasinghe, Rabindra R; Ghebreyesus, Tedros Adhanom; Snow, Robert W

    2010-01-01

    Summary In the past 150 years, roughly half of the countries in the world eliminated malaria. Nowadays, there are 99 endemic countries—67 are controlling malaria and 32 are pursuing an elimination strategy. This four-part Series presents evidence about the technical, operational, and financial dimensions of malaria elimination. The first paper in this Series reviews definitions of elimination and the state that precedes it: controlled low-endemic malaria. Feasibility assessments are described as a crucial step for a country transitioning from controlled low-endemic malaria to elimination. Characteristics of the 32 malaria-eliminating countries are presented, and contrasted with countries that pursued elimination in the past. Challenges and risks of elimination are presented, including Plasmodium vivax, resistance in the parasite and mosquito populations, and potential resurgence if investment and vigilance decrease. The benefits of elimination are outlined, specifically elimination as a regional and global public good. Priorities for the next decade are described. PMID:21035842

  14. Ranking species in mutualistic networks.

    PubMed

    Domínguez-García, Virginia; Muñoz, Miguel A

    2015-02-02

    Understanding the architectural subtleties of ecological networks, believed to confer them enhanced stability and robustness, is a subject of outmost relevance. Mutualistic interactions have been profusely studied and their corresponding bipartite networks, such as plant-pollinator networks, have been reported to exhibit a characteristic "nested" structure. Assessing the importance of any given species in mutualistic networks is a key task when evaluating extinction risks and possible cascade effects. Inspired in a recently introduced algorithm--similar in spirit to Google's PageRank but with a built-in non-linearity--here we propose a method which--by exploiting their nested architecture--allows us to derive a sound ranking of species importance in mutualistic networks. This method clearly outperforms other existing ranking schemes and can become very useful for ecosystem management and biodiversity preservation, where decisions on what aspects of ecosystems to explicitly protect need to be made.

  15. Ranking species in mutualistic networks

    PubMed Central

    Domínguez-García, Virginia; Muñoz, Miguel A.

    2015-01-01

    Understanding the architectural subtleties of ecological networks, believed to confer them enhanced stability and robustness, is a subject of outmost relevance. Mutualistic interactions have been profusely studied and their corresponding bipartite networks, such as plant-pollinator networks, have been reported to exhibit a characteristic “nested” structure. Assessing the importance of any given species in mutualistic networks is a key task when evaluating extinction risks and possible cascade effects. Inspired in a recently introduced algorithm –similar in spirit to Google's PageRank but with a built-in non-linearity– here we propose a method which –by exploiting their nested architecture– allows us to derive a sound ranking of species importance in mutualistic networks. This method clearly outperforms other existing ranking schemes and can become very useful for ecosystem management and biodiversity preservation, where decisions on what aspects of ecosystems to explicitly protect need to be made. PMID:25640575

  16. Malaria in Pregnancy

    PubMed Central

    Takem, Ebako Ndip; D’Alessandro, Umberto

    2013-01-01

    Pregnant women have a higher risk of malaria compared to non-pregnant women. This review provides an update on knowledge acquired since 2000 on P. falciparum and P.vivax infections in pregnancy. Maternal risk factors for malaria in pregnancy (MiP) include low maternal age, low parity, and low gestational age. The main effects of MIP include maternal anaemia, low birth weight (LBW), preterm delivery and increased infant and maternal mortality. P. falciparum infected erythrocytes sequester in the placenta by expressing surface antigens, mainly variant surface antigen (VAR2CSA), that bind to specific receptors, mainly chondroitin sulphate A. In stable transmission settings, the higher malaria risk in primigravidae can be explained by the non-recognition of these surface antigens by the immune system. Recently, placental sequestration has been described also for P.vivax infections. The mechanism of preterm delivery and intrauterine growth retardation is not completely understood, but fever (preterm delivery), anaemia, and high cytokines levels have been implicated. Clinical suspicion of MiP should be confirmed by parasitological diagnosis. The sensitivity of microscopy, with placenta histology as the gold standard, is 60% and 45% for peripheral and placental falciparum infections in African women, respectively. Compared to microscopy, RDTs have a lower sensitivity though when the quality of microscopy is low RDTs may be more reliable. Insecticide treated nets (ITN) and intermittent preventive treatment in pregnancy (IPTp) are recommended for the prevention of MiP in stable transmission settings. ITNs have been shown to reduce malaria infection and adverse pregnancy outcomes by 28–47%. Although resistance is a concern, SP has been shown to be equivalent to MQ and AQ for IPTp. For the treatment of uncomplicated malaria during the first trimester, quinine plus clindamycin for 7 days is the first line treatment and artesunate plus clindamycin for 7 days is indicated if

  17. Malaria Surveillance - United States, 2013.

    PubMed

    Cullen, Karen A; Mace, Kimberly E; Arguin, Paul M

    2016-03-04

    and implemented to have a substantial impact on the numbers of imported malaria cases in the United States. Fewer patients reported taking chemoprophylaxis in 2013 (32%) compared with 2012 (34%), and adherence was poor among those who did take chemoprophylaxis. Proper use of malaria chemoprophylaxis will prevent the majority of malaria illness and reduce the risk for severe disease (http://www.cdc.gov/malaria/travelers/drugs.html). Malaria infections can be fatal if not diagnosed and treated promptly with antimalarial medications appropriate for the patient's age and medical history, the likely country of malaria acquisition, and previous use of antimalarial chemoprophylaxis. Recent molecular laboratory advances have enabled CDC to identify and conduct molecular surveillance of antimalarial drug resistance markers (http://www.cdc.gov/malaria/features/ars.html). These advances will allow CDC to track, guide treatment, and manage drug resistance in malaria parasites both domestically and globally. For this to be successful, specimens should be submitted for all cases diagnosed in the United States. Clinicians should consult the CDC Guidelines for Treatment of Malaria and contact the CDC's Malaria Hotline for case management advice, when needed. Malaria treatment recommendations can be obtained online (http://www.cdc.gov/malaria/diagnosis_treatment) or by calling the Malaria Hotline (770-488-7788 or toll-free at 855-856-4713).

  18. Malaria Surveillance - United States, 2014.

    PubMed

    Mace, Kimberly E; Arguin, Paul M

    2017-05-26

    and prevent infections. VFR travelers continue to be a difficult population to reach with effective malaria prevention strategies. Evidence-based prevention strategies that effectively target VFR travelers need to be developed and implemented to have a substantial impact on the number of imported malaria cases in the United States. Fewer U.S. resident patients reported taking chemoprophylaxis in 2014 (27.2%) compared with 2013 (28.6%), and adherence was poor among those who did take chemoprophylaxis. Proper use of malaria chemoprophylaxis will prevent the majority of malaria illnesses and reduce risk for severe disease (https://www.cdc.gov/malaria/travelers/drugs.html). Malaria infections can be fatal if not diagnosed and treated promptly with antimalarial medications appropriate for the patient's age and medical history, likely country of malaria acquisition, and previous use of antimalarial chemoprophylaxis. Recent molecular laboratory advances have enabled CDC to identify and conduct molecular surveillance of antimalarial drug resistance markers (https://www.cdc.gov/malaria/features/ars.html) and improve the ability of CDC to track, guide treatment, and manage drug resistance in malaria parasites both domestically and globally. For this effort to be successful, specimens should be submitted for all cases diagnosed in the United States. Clinicians should consult CDC Guidelines for Treatment of Malaria in the United States and contact the CDC Malaria Hotline for case management advice, when needed. Malaria treatment recommendations can be obtained online at https://www.cdc.gov/malaria/diagnosis_treatment/ or by calling the Malaria Hotline at 770-488-7788 or toll-free at 855-856-4713.

  19. Cerebral Malaria.

    PubMed

    Marsden, P D; Bruce-Chwatt, L J

    1975-01-01

    Cerebral malaria is an acute diffuse encephalopathy associated only with Plasmodium falciparum. It is probably a consequence of the rapid proliferation of the parasites in the body of man in relation to red cell invasion, and results in stagnation of blood flow in cerebralcapillaries with thromobotic occlusion of large numbers of cerebral capillaries. The subsequent cerebral pathology is cerebral infarction with haemorrhage and cerebral oedema. The wide prevalence of P. falciparum in highly endemic areas results in daily challenges to patients from several infected mosquitoes. It is thus important to understand the characteristics of P. falciparum, since this is one of the most important protozoan parasites of man and severe infection from it constitutes one of the few real clinical emergencies in tropical medicine. One of the more important aspects of the practice of medicine in the tropics is to establish a good understanding of the pattern of medical practice in that area. This applies to malaria as well as to other diseases. The neophyte might be somewhat surprised to learn, for example that an experienced colleague who lives in a holoendemic malarious area such as West Africa, sees no cerebral malaria. But the explanation is simple when the doctor concerned has a practice which involves treating adults only. Cerebral malaria is rare in adults, because in highly endemic areas, by the age of 1 year most of the infants in a group under study have already experienced their first falciparum infection. By the time they reach adult life, they have a solid immunity against severe falciparum infections. In fact, "clinical malaria" could occur in such a group under only two circumstances: 1) in pregnancy, a patent infection with P. falciparum might develop, probably due to an IgG drain across the placenta to the foetus;2) in an individual who has constantly taken antimalarials and who may have an immunity at such a low level that when antimalarial therapy is interrupted

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

    PubMed Central

    Ototo, EN; Guiyun, Yan

    2011-01-01

    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. PMID:22015426

  1. Malaria in rural Mozambique. Part II: children admitted to hospital.

    PubMed

    Bassat, Quique; Guinovart, Caterina; Sigaúque, Betuel; Aide, Pedro; Sacarlal, Jahit; Nhampossa, Tacilta; Bardají, Azucena; Nhacolo, Ariel; Macete, Eusébio; Mandomando, Inácio; Aponte, John J; Menéndez, Clara; Alonso, Pedro L

    2008-02-26

    Characterization of severe malaria cases on arrival to hospital may lead to early recognition and improved management. Minimum community based-incidence rates (MCBIRs) complement hospital data, describing the malaria burden in the community. A retrospective analysis of all admitted malaria cases to a Mozambican rural hospital between June 2003 and May 2005 was conducted. Prevalence and case fatality rates (CFR) for each sign and symptom were calculated. Logistic regression was used to identify variables which were independent risk factors for death. MCBIRs for malaria and severe malaria were calculated using data from the Demographic Surveillance System. Almost half of the 8,311 patients admitted during the study period had malaria and 13,2% had severe malaria. Children under two years accounted for almost 60% of all malaria cases. CFR for malaria was 1.6% and for severe malaria 4.4%. Almost 19% of all paediatric hospital deaths were due to malaria. Prostration (55.0%), respiratory distress (41.1%) and severe anaemia (17.3%) were the most prevalent signs among severe malaria cases. Severe anaemia and inability to look for mother's breast were independent risk factors for death in infants younger than eight months. For children aged eight months to four years, the risk factors were malnutrition, hypoglycaemia, chest indrawing, inability to sit and a history of vomiting.MCBIRs for severe malaria cases were highest in children aged six months to two years of age. MCBIRs for severe malaria per 1,000 child years at risk for the whole study period were 27 in infants, 23 in children aged 1 to <5 years and two in children aged > or =5 years. Malaria remains the number one cause of admission in this area of rural Mozambique, predominantly affecting young children, which are also at higher risk of dying. Measures envisaged to protect children during their first two years of life are likely to have a greater impact than at any other age.

  2. Malaria surveillance--United States, 2010.

    PubMed

    Mali, Sonja; Kachur, S Patrick; Arguin, Paul M

    2012-03-02

    for the areas to which they had traveled. Forty-one cases were reported in pregnant women, among whom only two (5%) adhered to chemoprophylaxis. Among all reported cases, 176 (10%) were classified as severe infections, of which nine were fatal. The number of cases reported in 2010 marked the largest number of cases reported since 1980. Despite the apparent progress in reducing the global burden of malaria, many areas remain malaria endemic and the use of appropriate prevention measures by travelers is still inadequate. Travelers visiting friends and relatives (VFR) continue to be a difficult population to reach with effective malaria prevention strategies. Evidence-based prevention strategies that effectively target VFR travelers need to be developed and implemented to have a substantial impact on the numbers of imported malaria cases in the United States. A large number of pregnant travelers diagnosed with malaria did not take any chemoprophylaxis. Pregnant women traveling to areas in which malaria is endemic are at higher risk for severe malaria and must use appropriate malaria prevention strategies including chemoprophylaxis. Malaria prevention recommendations are available online (http://www.cdc.gov/malaria/travelers/drugs.html). Malaria infections can be fatal if not diagnosed and treated promptly with antimalarial medications appropriate for the patient's age and medical history, the likely country of malaria acquisition, and previous use of antimalarial chemoprophylaxis. Clinicians should consult the CDC Guidelines for Treatment of Malaria and contact the CDC's Malaria Hotline for case management advice, when needed. Malaria treatment recommendations can be obtained online (http://www.cdc.gov/malaria/diagnosis_treatment) or by calling the Malaria Hotline (770-488-7788 or toll-free at 855-856-4713).