ABSTRACT
Human African trypanosomiasis (HAT) or sleeping sickness is an endemic vector borne parasitic disease in many sub-Saharan countries. It is caused by a unicellular hemoflagellate parasite Trypanosoma brucei (T.b.), which is cyclically transmitted through the saliva of blood sucking tsetse flies. The vector is found only in Africa, between the fifteenth parallels north and south. Its habitat is the vegetation along watercourses and lakes, forest edges and gallery forests, extending to vast areas of scrub Savannah. The more chronic “Gambian” fatal form of sleeping sickness, which evolves over a period of several months or years predominates in West and Central Africa. It is caused by trypanosomes of the subspecies T.b. gambiense. The more fulminant “Rhodesian” form, T.b. rhodesiense, is found in East Africa, where a large variety of game and domestic animals serve as reservoir hosts. At the beginning of the twentieth century, HAT surpassed all other health problems in sub-Saharan Africa. By the late 1950s, the incidence of HAT decreased in all endemic countries of West and Central Africa as a result of mass detection and treatment campaigns. Political unrest and civil war have disturbed the public health infrastructure resulting in a resurgence of trypanosomiasis in tropical and subtropical Africa. Recent medical surveys have revealed a shockingly high prevalence in endemic areas of Africa.
