Developing a national atlas to support the progressive control of tsetse-transmitted animal trypanosomosis in Zambia.

Abstract

BACKGROUND: Tsetse flies (Diptera: Glossinidae) are the sole cyclical vectors of African trypanosomosis, a parasitic disease affecting both animals and humans. The national atlas of African animal trypanosomosis (AAT) and its tsetse vectors in Zambia is an initiative by the Tsetse and Trypanosomosis Control Unit (TTCU) within the Ministry of Fisheries and Livestock that aims to improve AAT surveillance and its progressive control by enhancing disease intelligence and data management. METHODS: All field data collected by the TTCU from April 2009 to July 2025 were systematically assembled, georeferenced and harmonised. The data included entomological information on tsetse flies collected using mobile and stationary trapping devices, as well as animal trypanosomosis data obtained through the buffy coat technique (BCT). RESULTS: Tsetse trapping was conducted in 3463 sites using mobile devices and in 478 locations using stationary traps. A total of 20,185 and 5189 flies were caught using the two data collection tools, respectively. Five species and subspecies of Glossina were detected: G. morsitans morsitans (65%), G. m. centralis (32%), G. pallidipes (2%), G. fuscipes martinii (0.8%) and G. brevipalpis (0.2%). As for AAT, 7652 animals (7348 cattle, 294 goats and 10 dogs) were tested in 148 locations. Of these, 329 animals (321 cattle, 7 goats and 1 dog) were found to be infected, with a prevalence of 4.37%. Trypanosoma congolense accounted for the highest number of infections (86%), with Trypanosoma vivax and Trypanosoma brucei representing 12% and 2% of the total infections, respectively. CONCLUSION: The national database of AAT and tsetse presented here established an effective information system to manage epidemiological data for the planning and monitoring of interventions against tsetse and trypanosomosis in Zambia. The atlas is planned to be regularly and promptly updated to ensure that current information is available to the TTCU, planners and other stakeholders involved in tsetse and AAT control.