Prevalence of Bovine Trypanosomosis and Tsetse Fly Density in Sayo Woreda, Oromia, Ethiopia

African animal trypanosomiasis is a vector-borne protozoan disease which is transmitted by tsetse fly and biting flies. Trypanosomiasis is endemic in many countries in Northern and Eastern Africa, Latin America, and Asia. A cross-sectional study conducted from September 2016 to June 2017 to assess the prevalence of bovine trypanosomiasis and apparent density of tsetse flies in four Kebeles of Sayo, Kelem Wollega, and Oromia of Ethiopia. Out of the 460 cattle parasitologically (Giemsa stained thin smear) examined for trypanosomes, 29 (6.3%) of them were found positive. Trypanosomiasis was significantly higher in older animals (16.4%) than the young (6%) and adults (3.2%) (p=0.002). The prevalence of trypanosomosis in cattle with medium body condition (8.6%) was significantly higher than the poor (6.3%) and good body conditioned animals (1.2%). Lower prevalence was detected in Ripha 5(4.2%) and Karobaha 5(5.1%) than in Minko lencha district 11 (9.2 %). The overall apparent densities of tsetse flies in each study area were determined by using 80 monopyramidal traps counted every 48 hours. The identified tsetse species in this study were Glossina tachnoides, Glossina morsitans sub morsitans, Glossina pallidipes, and Glossina fuscipes and their apparent density was 0.656 flies/trap/day while other biting flies were at a density of 0.9 flies/trap/day. Overall tsetse fly density of 1.225 flies/trap/day and 0.33 flies/trap/day were from savanna and riverine vegetation types respectively. Even though the density of all files was1.56 flies/trap/day, a relatively higher number of Glossina morsitans sub morsitans 50 (25.5%) was caught in savanna vegetation type. The present study showed that the prevalence of trypanosomosis and tsetse fly density was higher in savanna than riverine vegetation. Even though further assessment of integrated echo friendly control approaches are essential, grazing in riverine vegetation will help to minimize trypanosomosis distribution and tsetse fly exposure.