Abstract:
Piroplasmosis caused by differenttick-borne hemoprotozoan parasites ofthe genera Theileria and Babesia is among the most economically importantinfections of domestic ruminants
in sub-Saharan Africa. A survey for piroplasm infection was conducted in three locations
in Northern Ethiopia. Of 525 domestic ruminants surveyed, 80% of the cattle, 94% of the
sheep and 2% of the goats were positive for different Theileria spp. based on PCR of blood
followed by DNA sequencing. Sheep had a significantly higher rate of infection compared
with cattle (P < 0.0003) and both sheep and cattle had higher rates of infection compared
to 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 the
two Theileria spp. detected in small ruminants, T. ovis was highly prevalent (92%) in sheep
and 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 capracanis
and S. tenella were detected in one goat and a sheep, respectively. The widespread distribution of Theileria spp. among cattle in northern Ethiopia including the virulent T. annulata
and more mildly pathogenic T. mutans and T. orientalis, and the high infection rate in sheep
with the usually sub-clinical T. ovis indicate extensive exposure to ticks and transmission
of piroplasms with an important economic impact.
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