African Trypanosomiases

Abstract

The human trypanosomiases of Africa are infections caused by two subspecies of the hemoflagellate Trypanosoma brucei: T. brucei rhodesiense and T. brucei gambiense; these subspecies are transmitted to man through the bite of tsetse flies of the genus Glossina. Although the two subspecies are morphologically indistinguishable, they differ epidemio-logically and in their disease spectrum. Infection with T. brucei rhodesiense often results in a subacute fatal disease, whereas infection with T. brucei gambiense usually runs a more chronic course, manifested clinically by the typical sleeping sickness syndrome.¹ The human trypanosomiases are transmitted in the region of Africa between 15°N and 15°S latitude, where the environmental conditions correspond to those favorable for Glossina flies. The rhodesian form of the infection occurs largely in the eastern third of Central Africa, whereas the gambian infection is found mainly in the western half of this region. Data on the prevalence of the infections during the last two decades are grossly incomplete at present because of a decrease in surveillance and control activities.