Trypanosomosis in small ruminants maintained by low riverine tsetse population in central Nigeria

The prevalence of trypanosomosis was investigated over a 12-month period, among small ruminants grazing in known sleeping sickness endemic area of central Nigeria and under light riverine tsetse challenge. Analysis of the data from 304 Yankassa sheep and 239 West African DwarfxRed Sokoto goats indicated high mean prevalence (27.62%, confidence limits Cl: 0.232, 0.312). Interspecies difference between sheep (38.16%; 0.382, Cl: 0.332, 0.432) and goats (14.23%; 0.142, Cl: 0.102, 0.182) was highly significant (P<0.001). Infections were also significantly higher (P<0.05) with agro-pastoral (extensive) management, during the dry season and in adults compared to intensively managed animals, the wet season and young animals, respectively. Trypanosoma vivax was the predominant parasite encountered and accounted for over 49% of the infections. T. congolense and mixed populations were diagnosed at approximately 15% each while T. brucei were absent in caprines. The implications of these findings in the epidemiology of the diseases in both man and domestic animals is discussed.