Artificially induced Trypanosoma brucei brucei infection in Lagune and Borgou cattle in Benin.

Lagune (n = 10) and Borgou (n = 10) cattle of Benin were inoculated subcutaneously with Trypanosoma brucei brucei AnTat, 1.1E. Clinical signs, packed cell volume (PCV), parasitaemia, specific trypanolytic antibodies and haemolytic complement were monitored to evaluate the between-and-within breed variations. All the animals showed only transitory symptoms with clinical recovery within 20 days post infection. Infected animals showed a moderate drop in PCV after 5-10 days of infection. The drop in PCV at day 20 was 2.9 +/- 2.7% for Borgou and 1.2 +/- 1.8% for Lagune. Except two animals of Borgou breed, all animals developed detectable parasitaemia. Two peaks of parasitaemia, the first on day 5-6 and the second on day 9-10 post infection, were observed. Parasitaemia persisted for 25 days in two Borgou and one Lagune cattle. There were large individual variations in PCV and parasitaemia. AnTat 1.1 specific trypanolytic antibodies were detected from day 6-7 in all animals, except one Borgou and they persisted until the end of observation on day 30. A drop in serum haemolytic complement occurred corresponding to the first parasitaemic waves. After day 15, complement level was restored rapidly largely exceeding the initial values of day 0. The results indicate that all the artificially infected individuals belonging to the Borgou breed as well as to the better known Lagune breed are tolerant to Trypanosoma brucei brucei infection.