|Agricultural Development and Vector-Borne Diseases (FAO - HABITAT - UNEP - WHO, 1996, 91 p.)|
|Topic A: Vector-borne diseases of relevance to agriculture|
Slide A.7 Number of malaria cases reported by WHO Region
With respect to the global distribution of malaria, several issues should be borne in mind:
· the distribution map indicates risk and does not indicate intensity of transmission. Malaria has a patchiness in time and location, except in the so-called holo-endemic and hyper-endemic areas (epidemiological terms relating transmission intensity to clinical patterns) of sub-Saharan Africa.
· the majority of malaria cases in the world (90%) occur in sub-Saharan Africa
· the map does not distinguish between the various parasite species, the most important of which are the virulent Plasmodium falciparum and the more benign P. vivax. The latter predominates in the Eastern Mediterranean and in South Asia, even though the proportion of P. falciparum cases in the latter area is increasing.
· the map does not indicate the problems of drug resistant Plasmodium falciparum, spreading in South East Asia and in Africa
· malaria was successfully eradicated from Europe, parts of the Eastern Mediterranean, parts of North, Central and South America, and parts of the Western Pacific, mainly through the spraying of residual insecticides. These were without exception areas of unstable vivax malaria.
· current important malaria foci are associated with areas of rapid economic development, with demographic and environmental change, and areas characterized by civil strife or refugee problems. Urban malaria is gaining importance.