Abstract
Piroplasmosis caused by different tick-borne hemoprotozoan parasites of the genera Theile-ria and Babesia is among the most economically important infections of domestic ruminantsin sub-Saharan Africa. A survey for piroplasm infection was conducted in three locationsin Northern Ethiopia.
Of 525 domestic ruminants surveyed, 80% of the cattle, 94% of thesheep and 2% of the goats were positive for different Theileria spp. based on PCR of bloodfollowed by DNA sequencing. Sheep had a significantly higher rate of infection comparedwith cattle (P < 0.0003) and both sheep and cattle had higher rates of infection comparedto goats (P < 0.0001).
Four species of Theileria were detected in cattle: T. velifera, T. mutans,T. orientalis complex and T. annulata with infection rates of 66, 8, 4, and 2%, respectively.This is the first report of T. annulata, the cause of Tropical Theileriosis in Ethiopia. Of thetwo Theileria spp. detected in small ruminants, T. ovis was highly prevalent (92%) in sheepand rare in goats (1.5%) whereas T. seperata was infrequent in sheep (2%) and rare in goats(0.4%).
None of the animals were positive for Babesia spp.; however, Sarcocystis capracanisand S. tenella were detected in one goat and a sheep, respectively. The widespread distri-bution of Theileria spp. among cattle in northern Ethiopia including the virulent T. annulataand more mildly pathogenic T. mutans and T. orientalis, and the high infection rate in sheepwith the usually sub-clinical T. ovis indicate extensive exposure to ticks and transmissionof piroplasms with an important economic impact.