Survey on bovine trypanosomosis and its vector in Metekel and Awi zones of Northwest Ethiopia.

A cross-sectional study was conducted between November 2009 and December 2009 in the riverbank of Abay river tributaries, located in three districts of Awi and Metekel zones, Northwest Ethiopia. The prevalence of bovine trypanosomosis, associated risk factors and distribution as well as vector identification in the study area were considered. Blood samples were collected from 540 randomly selected local (zebu) breed of cattle in nine peasant associations of three districts and the assumed risk factors were recorded. The collected samples were examined using hematological and parasitological techniques. In this study, sixty-seven animals (12.42%) were infected with different species of trypanosomes. Most of the infections were due to T. congolense (77.6%) followed by T. vivax (14.9%), T. brucei (6.0%) and mixed infection of T. congolense and T. vivax (1.5%). There was no statistical significance (p>0.05) between sex, age and coat color of skin, but significant differences were observed in body condition, altitude and districts (p<0.05). Mean PCV value of infected (19.42%) and non-infected (24.13%) group of animals had significant variation; and mean PCV value of poor body condition was significantly different (p<0.001) from good body condition. A total of 3072 tsetse flies of riverine species or palpalis group (Glossina tachinoides) and biting flies were caught, of these 2792 (90.9%) were tsetse flies and the remaining were Stomoxys and Tabanus. The overall apparent densities of tsetse and biting flies were 6.49 and 0.65flies/trap/day, respectively and the difference was significant (p<0.05). The study revealed that bovine trypanosomosis is more prevalent in low land and in poor body condition animals in the study area. Tsetse distribution also coincides with altitude, where there was high tsetse catch in low land, but none in mid land. Therefore, prompt control strategy has to be designed and implemented in the area to minimize the distribution of tsetse as well as trypanosomosis prevalence.