Epilepsy and tropical parasitic infections in Sub-Saharan Africa: a review
Several reports have suggested that the high prevalence of epilepsy in sub-Saharan Africa is associated with the high prevalence of parasitic infections affecting the central nervous system. Though epidemiological evidence suggests an association between parasitic infections and epilepsy, the biological causal relationship has not been fully demonstrated for many of these infections. The objective of this paper is to review the available epidemiological evidence on the links between parasitic infections and epilepsy, the pathogenesis and the current gap of knowledge indicating the areas requiring further research. Data for this review were identified and collected using manual and electronic search strategies of published and unpublished sources. In Sub-Saharan Africa, the epidemiology of epilepsy remains unclear and given the differing study designs, the results of available epidemiological studies are difficult to interpret and compare. Evidence from surveys reported a median prevalence of 1.5%. Co-infection of parasitic infections and epilepsy in sub-Saharan Africa are common, particularly in areas characterized by poor hygiene standards. There is an epidemiological link on the association between epilepsy and various parasitic infections. However, the biological causal relationship requires further investigation in adequately designed studies. In conclusion, although several epidemiological and case control studies indicate a relationship between parasitic agents and epilepsy in sub-Saharan Africa, there is a considerable gap of knowledge on the cause and magnitude of the association. Thus, there is an urgent need for systematic epidemiological studies to understand the burden of epilepsy in areas endemic due to preventable parasitic infections, to prove a causal relationship, and to understand the impact of controlling these parasitic diseases on reduction of the burden of epilepsy.