The use of the antigen ELISA for the monitoring of trypanosomal infections in cattle in Zimbabwe

The antigen ELISA (Ag-ELISA) for the detection of trypanosomal was used in the diagnosis of bovine trypanosomiasis in Gokwe District, an area from which tsetse flies had been cleared recently; in Hwange Communal Land, which although free from tsetse flies for 20 years, was threatened by reinvasion; and as part of a national survey of vector-borne diseases to determine the extent and prevalence of trypanosomal infections throughout the country. In Gokwe and Hwange all the animals tested were negative for parasites by Buffy Coat Technique (BCT), while the Ag-ELISA results showed that 42.9% and 32.3% respectively of the animals were infected. In the national survey, trypanosomal antigens were detected in cattle at 46.1% of the locations from which samples were collected, most of them in tsetse free areas. These results could be due to reinvasion or persistence of tsetse flies in very small numbers, residual infections of low pathogenicity, or temporary introduction of flies by transport vehicles. (author). 4 refs, 5 figs, 2 tabs