An empirical malaria distribution map for West Africa

The objective of this study was to produce a malaria distribution map that would constitute a useful tool for development and health planners in West Africa. The recently created continental database of malaria survey results (MARA/ARMA 1998) provides the opportunity for producing empirical models a nd maps of malaria distribution at a regional and eventually at a continent al level. This paper reports on the mapping of malaria distribution for sub -Saharan West Africa based on these data. The strategy was to undertake a s patial statistical analysis of malaria parasite prevalence in relation to t hose potential bio-physical environmental factors involved in the distribut ion of malaria transmission intensity which are readily available at any ma p location. The resulting model was then used to predict parasite prevalenc e for the whole of West Africa. We also produced estimates of the proportio n of population of each country in the region exposed to various categories of risk to show the impact that malaria is having on individual countries. The data represent a very large sample of children in West Africa. It cons titutes a first attempt to produce a malaria risk map of the West African r egion, based entirely on malariometric data. We anticipate that it will pro vide useful additional guidance to control programme managers, and that it can be refined once sufficient additional data become available.