Trypanasoma Infection Rates In Glossina Species In Mtito Andei Division, Makueni County, Kenya

Abstract

This study was carried out to determine the infection rates of trypanosomes in Glossina species in Mtito Andei, Makueni County, Kenya. Tsetse species, G. longipennis and G. pallidipes were trapped and DNA isolated from their dissected internal organs (proboscis, salivary glands and mid-guts). The DNA was then subjected to a nested PCR assay using internal transcribed spacer primers and individual trypanosome species (T. vivax and T. c. Forest) identified following agarose gel electrophoresis. A total of 78 non teneral flies analyzed for trypanosomes infection revealed an average infection rate of 11.53% (9/78). The overall infection rates for the different trapping sites Kamunyu, Ngiluni, Kyusyani, Iviani and Nthunguni were 6.41%, 1.28%, 2.56%, 1.28% respectively. No infected tsetse were detected in Nthunguni and infection rates for the different sites were statistically different (P<0.05). G. longipennis was the most prevalent in Kamunyu while G. pallidipes was most prevalent in Iviani and Nthunguni. Kyusyani and Ngiluni areas had both tsetse species. Out of 78 flies analyzed, the prevalence of trypanosome infection in G. pallidipes and G. longipennis was 5.77% and 23.08% respectively and this difference was significant. Most of G. pallidipes were infected with T. vivax (3.85%) while the rest were infected with T. congolense (1.92%). This was in contrast to G. longipennis which were only infected with T. vivax (23.08%). The study showed overall prevalence of 10.26% for T. vivax and 1.28% T. congolense with T. vivax infections being higher in both tsetse species. The infection rates with these two trypanosome species was also statistically different (P<0.05) and were higher in males (13.95%) than in female flies (8.57%), however, this difference was not significant. There was a strong positive relationship between the mean apparent densities and infection rates confirming the importance of this parameter as an indicator of African animal trypanosomiasis. These findings suggest the importance of designing control strategies targeting the biological vector

(tsetse), mechanical vectors (Tabanus and Stomoxys spp), and the trypanosome parasites.