Epidemiological investigation of trypanosomosis in livestock and distribution of vector in Dabo Hana district, Southwest Oromia, Ethiopia

The trypanosomosis remains unresolved due to its impact on various hosts, leading to production losses in Ethiopia. In the Southwest of Oromia, multiple livestock species share grazing land in tsetse-infested areas. Thus, a cross-sectional study was conducted from December 2020 to December 2021 to determine the prevalence and associated risk factors of trypanosomosis in bovines, small ruminants, and equines, as well as the distribution of the vector in the Dabo Hana district of Southwest Oromia, Ethiopia. A vector survey was carried out using 60 monoconical traps placed at intervals ranging from about 100 to 200 m. Out of the 1441 flies captured, 86.2 % were Glossina, 7.84 % were Stomoxys, and 5.96 % were Tabanus. The overall apparent density of flies was 12 flies per trap per day. Among the 1242 caught Glossina species, 85 % were identified as G. tachinoides and 15 % as G. m. submorsitans. The average age of male tsetse flies was 28 days, and the overall infection rate of trypanosomes in tsetse flies was 4.8 %. A total of 701 blood samples (190 from bovines, 384 from small ruminants, and 127 from equines) were analyzed using buffy coat and Giemsa techniques. The prevalence of trypanosomosis was found to be 10 % in bovines, 4.2 % in small ruminants, and 3.1 % in equines. A significant difference (P < 0.05) in trypanosome infection was observed among the three host species, as well as with respect to the age and body condition of the animals. The predominant cause of infection was T. congolense, accounting for 74.4 % of cases. The mean packed cell volume (PCV) values of infected bovines, small ruminants, and equines were significantly lower (P < 0.05) compared to those of noninfected animals. Trypanosomosis is a major livestock disease in the study area. The findings provide valuable insights into the prevalence and infection rates of trypanosomosis, identify the affected species, and highlight significant risk factors, such as age, body condition, and vector distribution. Implementing sustainable and integrated practices for trypanosomosis control is crucial, and conducting molecular techniques in different seasons is also recommended.