High trypanosome infections in Glossina palpalis palpalis Robineau-Desvoidy 1830 in southern Kaduna state, Nigeria

Abstract

A survey was undertaken to determine the prevalence of trypanosome infection in Glossina species in Kaura Local Government Area (LGA) of Kaduna State, Southern Guinea Savanna, Nigeria, aimed at identifying areas to be prioritized for area-wide tsetse eradication. The flies were trapped from a relic forest and also from 22 locations spread within the LGA and dissected to determine infection rates and infection types. Glossina palpalis palpalis Robineau-Desvoidy 1830 was the only tsetse species encountered both within the relic forest and the 22 locations sampled; its distribution was strictly riverine. Out of the 409 non-teneral flies dissected in the relic forest, 18.1 ± 0.02%, were infected with trypanosomes, with infections of the vivax-group dominating (76.92%) over the congolensegroup (23.01%). Of the 690 flies caught from 22 locations, 9.9 ± 1.0% were infected, 69.12% with vivax-group and 30.88% with congolense-group. Infections of the brucei-group were not encountered throughout the investigation period. The high prevalent figure of 12.64% recorded in the flies from both the relic forest and other locations portray the area as highly risky, with Bondong, Manchok and Kadarko districts being highly endemic, followed by a region of medium prevalence at Kukum district and a region of low endemicity within the mountain ranges of Zankan district. A well articulated vector eradication programme that will target G. p. palpalis and the various species of other biting dipterans is recommended as the solution to the recurring nagana problem in the area.

Keywords: Glossina palpalis palpalis, Trypanosoma vivax, T. congolense, Kaduna State, Nigeria