Malaria

Malaria Forum

admin — 2007-01-04T21:17:48Z

Addressing the Challenges of Malaria Control

ylin — 2007-03-08T21:45:08Z

Vulnerability to climate induced highland malaria in East Africa

ylin — 2007-03-09T00:58:46Z

Malaria—a Shadow over Africa

ylin — 2007-03-09T01:06:36Z

Reduction in severe disease and death from falciparum malaria in Africa requires new, more effective and inexpensive public health measures. The completed genomes of Plasmodium falciparum and its vector Anopheles gambiae represent a big step toward the discovery of these needed tools.

Modelling Malaria Risk in East Africa at High-spatial Resolution

ylin — 2007-03-09T01:12:41Z

Keywords: East Africa, malaria parasite prevalence, remote sensing, mapping Objectives: Malaria risk maps have re-emerged as an important tool for appropriately targeting the limited resources available for malaria control. In Sub-Saharan Africa empirically derived maps using standardized criteria are few and this paper considers the development of a model of malaria risk for East Africa. Methods: Statistical techniques were applied to high spatial resolution remotely sensed, human settlement and land-use data to predict the intensity of malaria transmission as defined according the childhood parasite ratio (PR) in East Africa. Discriminant analysis was used to train environmental and human settlement predictor variables to distinguish between four classes of PR risk shown to relate to disease outcomes in the region. Results: Independent empirical estimates of the PR were identified from Kenya, Tanzania and Uganda (n=330). Surrogate markers of climate recorded on-board earth orbiting satellites, population settlement, elevation and water bodies all contributed significantly to the predictive models of malaria transmission intensity in the sub-region. The accuracy of the model was increased by stratifying Africa into two ecological zones. In addition, the inclusion of urbanization as a predictor of malaria prevalence, whilst reducing formal accuracy statistics, nevertheless improved the consistency of the predictive map with expert opinion malaria maps. The overall accuracy achieved with ecological and urban stratification was 62% with surrogates of precipitation and temperature being among most discriminating predictors of the PR. Conclusions: It is possible to achieve a high degree of predictive accuracy for Plasmodium falciparum parasite prevalence in East Africa using high-spatial resolution environmental data. However, discrepancies were evident from mapped outputs from the models which were largely due to poor coverage malaria training data and the comparable spatial resolution of predictor data. These deficiencies only be addressed by more random, intensive small areas studies of empirical estimates of PR

Malaria and HIV interactions and their implications for public health policy

ylin — 2007-03-09T01:15:12Z

The Economic Burden of Malaria

ylin — 2007-03-09T20:09:58Z

Malaria and poverty are intimately connected. Controlling for factors such as tropical location, colonial history, and geographical isolation, countries with intensive malaria had income levels in 1995 of only 33% that of countries without malaria, whether or not the countries were in Africa. The high levels of malaria in poor countries are not mainly a consequence of poverty. Malaria is geographically specific. The ecological conditions that support the more efficient malaria mosquito vectors primarily determine the distribution and intensity of the disease. Intensive efforts to eliminate malaria in the most severely affected tropical countries have been largely ineffective. Countries that have eliminated malaria in the past half century have all been either subtropical or islands. These countries’ economic growth in the 5 years after eliminating malaria has usually been substantially higher than growth in the neighboring countries. Cross-country regressions for the 1965–1990 period confirm the relationship between malaria and economic growth. Taking into account initial poverty, economic policy, tropical location, and life expectancy, among other factors, countries with intensive malaria grew 1.3% less per person per year, and a 10% reduction in malaria was associated with 0.3% higher growth. Controlling for many other tropical diseases does not change the correlation of malaria with economic growth, and these diseases are not themselves significantly negatively correlated with economic growth. A second independent measure of malaria has a slightly higher correlation with economic growth in the 1980–1996 period. We speculate about the mechanisms that could cause malaria to have such a large impact on the economy, such as foreign investment and economic networks within the country.

Assembling a global database of malaria parasite prevalence for the Malaria Atlas Project

ylin — 2007-03-09T20:17:57Z

Background: Open access to databases of information generated by the research community can synergize individual efforts and are epitomized by the genome mapping projects. Open source models for outputs of scientific research funded by tax-payers and charities are becoming the norm. This has yet to be extended to malaria epidemiology and control. Methods: The exhaustive searches and assembly process for a global database of malaria parasite prevalence as part of the Malaria Atlas Project (MAP) are described. The different data sources visited and how productive these were in terms of availability of parasite rate (PR) data are presented, followed by a description of the methods used to assemble a relational database and an associated geographic information system. The challenges facing spatial data assembly from varied sources are described in an effort to help inform similar future applications. Results: At the time of writing, the MAP database held 3,351 spatially independent PR estimates from community surveys conducted since 1985. These include 3,036 Plasmodium falciparum and 1,347 Plasmodium vivax estimates in 74 countries derived from 671 primary sources. More than half of these data represent malaria prevalence after the year 2000. Conclusion: This database will help refine maps of the global spatial limits of malaria and be the foundation for the development of global malaria endemicity models as part of MAP. A widespread application of these maps is envisaged. The data compiled and the products generated by MAP are planned to be released in June 2009 to facilitate a more informed approach to global malaria control.

Children’s anemia levels in West Africa: a good proxy for malaria morbidity?

ylin — 2007-03-09T20:26:45Z

Malaria is a major cause of morbidity and mortality in young children in sub-Saharan Africa. Major public health initiatives, such as the Roll Back Malaria program, have made it a global health priority to improve the malaria situation in the next decade. In Africa, however, routine health information is not available to monitor progress on reducing malaria morbidity. The objective of this paper is to examine the utility of using child hemoglobin measures collected in population-based studies as an indicator to monitor changes in the malaria situation. A logistic regression analysis models the effects of malaria prevalence on the probability of serious anemia (Hb<8 g/dl) while controlling for child nutrition and other factors hypothesized to relate to anemia. Individual-level information on children age 6-59 months in five sub-Sahara African countries includes geospatially linked data from three sources: child health and sociodemographic information from the Demographic and Health Surveys (DHS); malaria prevalence estimates from the Mapping Malaria Risk in Africa (MARA) project; and urban extent measures from the Global Rural-Urban Mapping Project (GRUMP). Findings indicate that children in areas of moderate malaria prevalence run the highest risk of serious anemia. These findings are not unlike findings from previous studies, and plausible explanations are presented. Hemoglobin measures are reliable measures of anemia (and if untreated, anemia is an almost inevitable outcome of malaria especially in children 6-23 months); the validity of hemoglobin measures depends on whether or not the anemia test takes place in malaria transmission season.

Mapping Malaria Risk in the Highlands of Africa

ylin — 2007-03-09T20:29:09Z

MARA/HIMAL Technical Report

Changing national malaria treatment policy

admin — 2007-11-08T02:42:47Z

The Clinic Supervisor's Manual

ylin — 2007-03-09T21:00:44Z

The purpose of this manual is to provide a set of flexible, adaptable tools, and guidelines to support supervisors in their role of improving the quality of care in the clinics. It is especially helpful for focusing managers on the key elements of integrated primary health care as they simultaneously integrate new interventions for HIV/AIDS, tuberculosis, and malaria.

Geographic Information Systems for the Study and Control of Malaria

ylin — 2007-03-09T19:17:47Z

Large amounts of information are necessary for almost all aspects of malaria control programs. GIS offer the ability to process quantities of data beyond the capacities of manual systems. Data are stored in a structured digital format, which permits rapid retrieval and use. In addition, data may be quickly compiled into documents, using techniques such as automatic mapping and direct report printouts

Malaria Indicator Survey Incorporating Geographic Information into MEASURE Surveys

ylin — 2007-03-09T19:25:43Z

This document is designed to be a start-to-finish guide to Global Positioning System data collection in MEASURE projects. This guide provides background information on GPS, how the technology works, how GPS data is collected, and how it is used in the context of MEASURE surveys. Checklists are provided to identify hardware, software and training needs during the course of a survey.