Trypanosome Infection Rate in the Tsetse Species, Glossina Pallidipes Austen, in a Rural Situation in Kenya

Abstract

A study was carried out during the wet and dry seasons, between October 1978 and May 1980 (altogether comprising four wet and three dry seasons), on the trypanosome infection rate in the tsetse species, Glossina pallidipes Austen, in rural situations in the Kiboko and Nkruman areas in Kenya. There were some sex and age differences with respect to trypanosome infection. Female tsetse showed higher infection rates, and old flies, both male and female, also showed relatively higher trypanosome infection rates. Infections with Trypanosoma vivax and T. congolense were different, both as regards to seasons and locality: the infection rate with the latter was higher in Kiboko than in Nkruman, and varied seasonally; while the infection rate with T. vivax did not vary significantly with seasons. The kind of traps used for sampling tsetse influenced the trypanosome infection rate indirectly by having a direct influence on the age structure of tsetse. The vertebrate hosts of tsetse in the two areas played an important role: the infection rates of tsetse with T. vivax and T. congolense were high in areas with a high density of bovids.