Susceptibility of African buffalo and Boran cattle to intravenous inoculation with Trypanosoma congolense bloodstream forms.

Abstract

This study compares the susceptibility of African buffalo (Syncerus caffer) and Boran cattle (Bos indicus) to intravenous infection with T. congolense blood stream forms. The trypanosomes multiplied in the buffaloes and the Boran and reached levels of detectable parasitaemia 4 days after infection in the Boran and 10 days after infection in the buffalo. The cattle developed severe anaemia and had to be treated 60 days after infection to save them from dying whereas the buffaloes did not develop any signs of anaemia and did not require treatment. The Boran cattle showed high levels of parasitaemia persisting throughout the experimental period with some fluctuations. The parasitaemia in the buffaloes reached a peak of 5 x 10(3)/ml, 100 fold below the maximum level in cattle, it was intermittent and by the end of the experimental period (60 days), 3 out of 4 buffaloes had eliminated the parasites from circulation. Neutralizing antibodies were detected at the time of peak parasitaemia or soon after the 1st peak parasitaemia in buffaloes whereas in the Boran cattle neutralizing antibody could not be detected until after several peaks of parasitaemia. Neutralizing antibody persisted both in the Boran and buffaloes until the end of the experimental period.