Observations on the epidemiology of ruminant trypanosomosis in Kano State, Nigeria

The epidemiology of ruminant trypanosomosis was investigated during a two-year period in Kano State, Nigeria. Prevalence was 5.3 +/- 1.3% (mean +/- confidence interval), 1.2 +/- 1.6% and 0.7 +/- 1.3% in cattle, sheep and goats, respectively. Prevalence of bovine trypanosomosis was higher during the second year (6.1%) than in the first (4.8%). Infections doubled during the rains (7.6%) in comparison with an average of 3.8% during the dry season. The northern guinea vegetational zone recorded a high infection rate (Tudun-Wada local government area (LGA), 16.7%). It was the only area in which tsetse flies (Glossina tachinoides) were encountered. Nevertheless, haematophagous flies were common in the sudan savanna; tabanids were ubiquitous. Trypanosoma vivax infected 3.0% of bovine herds and was responsible for 57.6% of all diagnosable cases. It is suggested that vector control in Tudun-Wada LGA and chemoprophylaxis may break the transmission cycle of ruminant trypanosomosis in the area.