Tsetse and trypanosomiasis survey of Southern Darfur Province, Sudan. I. Bovine trypanosomiasis.

During a survey of Southern Darfur Province, Sudan blood samples from over 4,000 migratory cattle were analysed to determine levels of anaemia and trypanosome parasitaemia by buffy coat examination of microhaematocrit centrifuged samples. Levels of trypanosomal infections in the herds correlated well with their risk of exposure to tsetse being significantly lower at increasing distance from tsetse foci. Trypansoma vivax infections predominated in all herds, increasingly so with increasing distance from tsetse foci. Packed cell volume values could not be used to assist in trypanosome diagnosis at either individual or herd levels and the lack of correlation between anaemia and parasitaemia is suggested as evidence of a degree of trypanosomal tolerance in the Western Baggara cattle. Drug use and problems of drug resistance are discussed. Bovine trypanosomiasis is largely under control at present but requires continued surveillance (particularly of drug use) to prevent future problems as tsetse/cattle interactions increase.