Vector identification, prevalence and anemia of bovine trypanosomosis in Yayo District, Illubabor Zone of Oromia Regional State, Ethiopia

Abstract

Trypanosomosis is one of the major impediments to livestock development and
agricultural production in Ethiopia. It is cyclically transmitted by tsetse flies but
also mechanically tsetse flies and by other biting flies. A cross-sectional study was
conducted to identify the density and diversity of vectors and also the prevalence of
bovine trypanosomosis from October, 2014 to May, 2015. The study was conducted
in four selected settlement areas of the Yayo district in the Illubabor zone of Oromia
Regional State, Ethiopia. Standard methods of sampling and identification were employed for both entomological and parasitological examination. Four species of the genus Glossina (Glossina morsitans submorsitans, Glossina pallidipes, Glossina tachinoides and Glossina fuscipes) and two genera of biting flies (Stomoxys and Tabanus) were caught and identified. The overall apparent density of flies caught was 1095 (9.78 flies per trap per day), of which 410 (3.7 flies per trap per day) was Glossina species. Out of a total 488 cattle examined, 19 (3.9%; 95% CI: 2.36%-6.1%) were found infected with trypanosomes. Three species were detected
in the study area namely T. congolense 16(84.21%), T. vivax 2(10.53%) and T. brucei 1(5.26%). The prevalence of trypanosomosis was not significantly affected by all risk factors considered (p>0.05). Trypanosomosis significantly affected the status of anemia or packed cell volume (p<0.05). The mean PCV of parasitemic animals were significantly lower than that of aparasitemic ones (P<0.05). The prevalence of anemia was 19.67% (95%CI: 16.24-23.48) and not significantly affected by the different risk factors considered (P>0.05) with the exception of Geri (Peasant association) which have shown the lowest anemia prevalence  (P<0.05).The relative abundance of Glossina species caught and trypanosome detected confirmed the continuous challenge of the disease in the settlement areas. Therefore, the ongoing community based tsetse and trypanosomosis  prevention/control strategy should be strengthened in the area.

Keywords: Traps, Glossina, Packed cell volume, Trypanosoma, Buffy coat, Yayo district