Studies in leishmaniasis in the Anglo-Egyptian Sudan. Part I.—Epidemiology and general considerations

Abstract

1. 1. Leishmaniasis is endemic in certain areas of the Sudan, and sporadic cases have occurred in other areas. 2. 2. Visceral, oral, and cutaneous leishmaniasis have been found existing side by side in the same areas, but the visceral form is by far the most common. 3. 3. In the endemic areas, the principal incidence of kala-azar is found in rural situations, in the vicinity of water, and associated with the presence of vegetation. 4. 4. Four small outbreaks of kala-azar have occurred among Sudanese troops on duty in uninhabited or sparsely populated country. 5. 5. Canine leishmaniasis is unknown in the Sudan, the only natural animal infection being cutaneous leishmaniasis in a horse. 6. 6. As knowledge exists at present, the only sandfly of the major group, whose distribution in the Sudan bears any significant relation to that of kala-azar is Phlebotomus langeroni. 7. 7. Epidemiological evidence points to the possibility of the infection being carried on by some alternative or reservoir host, the nature of which is at present unknown. 8. 8. It is suggested that the almost consistent failure to produce infection by the bite of infected sandflies may in itself indicate the existence of some reservoir host, more specifically adapted to the parasite than man or the ordinary laboratory animals which have been used for the experiments.