Molecular Epidemiology of Trypanosomes in Tsetse Flies in the Livestock-wildlife-Human interface of Eastern Zambia

Abstract

ABSTRACTIntroductionTrypanosomiasis is caused by several species of trypanosomes. The disease is endemic in Eastern Zambia, particularly in the Luangwa River valley. There is a significant threat as many people are at risk of the infection. The disease is classified as a neglected tropical disease. Previously, Trypanosome epidemiological studies in this area focused on using low-sensitive parasitological diagnostic tools to determine the prevalence in animals and some few investigations on trypanosomiasis infection rates in tsetse flies. Livestock production, crop production and jobs in the tourism sector are the primary sources of livelihood in the south Luangwa national park. The South Luangwa National Park settlement town of Mfuwe is an economically and ecologically important area. The presence of trypanosomiasis repetitively threatens tourism and livelihoods, hence the forthcoming need to clarify the trypanosomiasis situation and to advocate the best tsetse and trypanosomiasis control measures in the area. These threats negatively affect the country’s Forex because fewer tourists are visiting.Material and methodsA cross-sectional study that was conducted in Mfuwe of the Eastern Province of Zambia to determine trypanosome infections in tsetse flies. Trapping of the tsetse flies involved the use of epsilon traps and black screen fly rounds in four different vegetation zones, namely open savannah, closed savannah, Montane and riverine. Diagnosis of trypanosome infections in trapped tsetse flies was achieved using a nested PCR which employed the use of two sets of primers targeting the ITS genes.ResultsTwo hundred twenty-three (223) tsetse flies were captured, and only 213 were processed for laboratory analysis. The highest catches from the areas selected were (153) of Tsetse flies in montane, followed by areas near the open forest (lagoons), (48) whereas the lowest catches was recorded in the riverine areas with 22 catches. The species found in these areas wereGlossina morsitans morsitansandGlossina palpalis,butGlossina brevipalpiswere not found,. The overall prevalence using a nested PCR of the identified trypanosome infection rates in tsetse flies was 18.3% (p < 0.001). The difference in prevalence between sampling areas were significant. Statistically significant differences (p < 0.001) were observed when the prevalence of trypanosome infections was compared by season. The Trypanosoma species found wereT.congolense, T.vivax, T.bruceiandT.theileri.ConclusionsThe results of this study showed that location has a significant contribution to the trypanosome infection rates in the tsetse vector at the Wildlife-Livestock-human interface of the Luangwa valley. The results are essential for designing community-wide tsetse and trypanosomiasis control interventions and planning sustainable regimes for mitigating the burden of trypanosomiasis.