Trypanosome infections in domestic animals in Liberia

In 5 domestic animal species of the Liberian rain forest, investigations were done on the infection rates with trypanosomes of the subgenera Nannomonas, Duttonella and Trypanozoon and on possible reservoir hosts for Trypanosoma (T.) brucei gambiense. Serological screening (indirect fluorescent antibody test) revealed that infection rates with Trypanosoma spp. were in N'Dama cattle 80.4%, in pigs 76.0%, in dogs 48.5%, in goats 35.1% and in sheep 28.1%. In N'Damas, antibodies to T. (N.) congolense and to T. (D.) vivax predominated and were distributed homogeneously; in pigs, antibodies to T. (N.) congolense were found most frequently. In dogs, antibodies to T. (N.) congolense and to T. (T.) b. brucei, and in goats and sheep antibodies to all 3 species were distributed homogeneously. Strong serological reactions (titres greater than 1:320) to T. (T.) b. brucei antigen were found most frequently in pigs (20.0%), in cattle (9.8%) and in dogs (9.5%). As suspicious reservoir hosts for T. (T.) b. gambiense, pigs (117) and dogs (105) were examined parasitologically in order to isolate Trypanozoon stocks for further infraspecific characterization. 56.4% of the pigs (14.5% Trypanozoon, 23.1% mixed Trypanozoon/Nannomonas, 18.8% Nannomonas), and 38.2% of the dogs (2.9% Trypanozoon, 14.3% mixed Trypanozoon/Nannomonas, 21.0% Nannomonas) were found to be infected. The sensitivities of the thick smear, the haematocrit centrifugation technique and the animal inoculation using Mastomys natalensis were described. 32 trypanosome stocks containing Trypanozoon were stabilized.