Sexually transmissible agent and African Kaposi's sarcoma

Kaposi's sarcoma (KS) has a higher incidence in some parts of Africa than anywhere else in the world. Recent studies in western homosexual men with AIDS-KS suggest that KS may be caused by a putative sexually transmissible agent. Our analytical review of studies on KS in Africa before and during the AIDS era reveals a disparate epidemiological picture. Its occurrence in sexually inexperienced children; overwhelming male preponderance in an almost exclusively heterosexual population; rarity of concordant couples in areas of very high incidence; sequestration of high incidence to Eastern and Central Africa; and regional variations in incidence even in high-incidence countries are all difficult to reconcile with a conventional sexually transmissible aetiology. There is a need for prospective studies specifically designed to test the hypothesis in Africa. Also, we recommend that studies pursuing the aetiology of KS in western countries be linked with studies in high incidence areas in Africa.