Current Tsetse and Trypanosomosis Situation on Jos Plateau, Nigeria. Epizootiological Factors that May Enhance Disease Transmission and Spread

Abstract

Tsetse and trypanosomosis surveys were carried out in Jos-East, Riyom, Bassa and Bokkos local government areas (LGAs) of Jos Plateau, Nigeria. They followed reports of cases of trypanosomosis that led to the death of several livestock animals in the areas. Biconical and Nitse traps were pitched in suspected tsetse habitats. Also, cattle and sheep from selected native and Fulani herds within the areas surveyed were screened. Altogether 240 tsetse flies were caught, comprising 114 Glossina tachinoides and 126 G. palpalis palpalis, and revealing an overall apparent density of 4.63 flies/trap/day. Fly dissection showed an overall infection rate of 1.67% due to Trypanosoma brucei and T. vivax. Also, 87 G. tachinoides pupae were collected from Bassa and Jos-East LGAs. Other biting flies totaling 1536 were caught (Stomoxys, Tabanus and Haematopota). A total of 1053 cattle and 65 sheep were screened for trypanosome infection. The hematocrit centrifugation, animal inoculation, and morphological differential techniques were used to determine trypanosome species and prevalence rates. Results revealed a 7.79% prevalence rate in cattle due to T. brucei, T. congolense, T. vivax, and T. theileri, and a 3.08 prevalence rate in sheep due to T. vivax. The main factors that may predispose Jos Plateau to tsetse presence and trypanosomosis infection include dry and rainy seasons’ cattle migrations across the plateau to and from tsetse infested areas, abundance of other biting flies, changes in climatic conditions and increased human activities. These findings have debunked the protracted notion upholding Jos Plateau to be tsetse and trypanosomosis free; hence the safety of resident and migrant livestock, which unfortunately have increased in recent times, may no longer be guaranteed because of the trypanosomosis risk.