Entomological and epidemiological assessment of Glossina species in relation to the prevalence of trypanosomiasis in selected area councils of Abuja

Abstract

African trypanosomiasis remains a major constraint to livestock productivity and public health in sub-Saharan Africa. This study assessed the distribution, species composition, seasonal abundance, and trypanosome infection prevalence of Glossina species across six area councils of the Federal Capital Territory (FCT), Abuja, Nigeria. A cross-sectional entomological survey was conducted from January to December 2022 using 48 acetone-baited biconical traps deployed in riverine and gallery forest habitats, for a total of 132 trap-days. A total of 4,991 captured flies were morphologically identified. Of these, 2,736 were classified as teneral flies, while the remaining 2,255 non-teneral flies were dissected and examined microscopically for trypanosome infection. Glossina palpalis was the dominant species, accounting for 91% of the individuals, while Glossina tachinoides made up the remaining 9%. The abundance of tsetse flies showed marked spatial and seasonal variation, peaking during the wet season, with the highest total catch recorded in Abaji. Female flies (n = 2,723) were significantly more abundant than male flies (n = 2,268) (t = 2.431, p = 0.029). Of the non-teneral flies examined for the presence of Trypanosoma spp., 744 were found to be infected, for an overall prevalence of 33%. Trypanosoma vivax was the predominant species (27%), followed by Trypanosoma congolense (5%) and Trypanosoma brucei (1%). The data indicated that the prevalence of infection was higher in female flies than in males. Notably, the highest infection prevalence was in Kwali, suggesting that high vector abundance does not always correspond directly to the intensity of infection. These findings demonstrate heterogeneous vector distribution and infection patterns across the FCT and highlight the need for targeted, seasonally informed vector control, routine surveillance, and community-based interventions to reduce tsetse fly populations and trypanosome transmission.