Bovine tuberculosis in the Lake Victoria zone of Tanzania and its possible consequences for human health in the HIV/AIDS era.

A total of 8190 cattle from 42 well-managed herds in the Lake Victoria zone of Tanzania were tested for bovine tuberculosis by a single comparative intradermal test (SCITT) using avian and bovine purified protein derivative (PPD) antigens. The prevalence of bovine tuberculosis in this area was found to be 0.2%. There was significant variation (p < 0.001) among the herds tested in the four regions in this zone (Kagera, Mara, Mwanza and Shinyanga). The highest prevalence (2.12%) was in a herd of 566 cattle which had recently arrived in Kagera region from Dar-es-Salaam. None of the 915 cattle tested in Shinyanga or of the 254 resident cattle in the Kagera region were positive by SCITT. This area, and particularly the Kagera region, has the highest human morbidity and mortality due to the acquired immunodeficiency syndrome in Tanzania. Therefore, the presence of bovine tuberculosis in cattle necessitates further investigations on the role of animal-derived tuberculosis in human health.