A one health investigation of pathogenic trypanosomes of cattle in Malawi

Parasitic protozoan trypanosomes of the genus Trypanosoma cause infections in both man and livestock in Africa. Understanding the current spatial distribution of trypanosomes, herd-level factors associated with Trypanosoma brucei infection as well as local knowledge of African trypanosomosis is key to its prevention and control. A cross-sectional study was performed that sampled 53 livestock farmers and 444 cattle throughout Malawi. Cattle were screened for trypanosomes using serology and molecular techniques. Questionnaires were administered to livestock herders and incidence of hospital diagnosed human trypanosome infections was estimated from reports submitted to the Department of Health Unit. The apparent prevalence of trypanosome species based on molecular detection was low for Trypanosoma brucei (2%; 95 % CI: 1-4 %) and Trypanosoma congolense (3%; 95 % CI: 2-5 %) but higher for Trypanosoma theileri (26 %; 95 % CI: 22-30 %). The central region of the country was identified as being at a higher risk of T.brucei infection. One of the sampled cattle was confirmed as being infected with Trypanosoma brucei rhodesiense. Human trypanosome cases were more frequently reported in the northern region with an estimated incidence of 5.9 cases per 100,000 people in Rumphi District. The control of zoonotic diseases that impact poor livestock herders requires a One Health approach due to the close contact between humans and their animals and the reliance on animal production for a sustainable livelihood.