Molecular detection of Anaplasma species in questing ticks (ixodids) in Ethiopia

Objective To identify Anaplasma spp. in questing ticks with emphasis on Anaplasma phagocytophilum ( A. phagocytophilum ) and Anaplasma ovis ( A. ovis ) in Ethiopia. Methods DNA extracted from 237 questing ticks [ Rhipicephalus evertsi ( R. evertsi ) ( n = 61), Rhipicephalus pulchellus ( R. pulchellus ) ( n = 54), Rhipicephalus decoloratus ( n = 1), Amblyomma variegatum ( n = 22), Amblyomma lepidum ( n = 36), Amblyomma nymphs ( n = 6), Amblyomma gemma ( n = 7) and Hyalomma marginatum ( Hy. marginatum ) ( n = 53)] were tested by PCR-RFLP assay. Results Overall 32 (13.33%; 95% confidence interval: 9.8%–18.3%) of the ticks were positive for Anaplasma spp. DNA. Anaplasma marginale was detected in Hy. marginatum and R. pulchellus. Anaplasma centrale was identified in R. evertsi, R. pulchellus and Hy. marginatum. A. ovis was detected in R. evertsi, Amblyomma spp. and Hyalomma spp. A. phagocytophilum was detected only in R. pulchellus and Anaplasma sp. omatijenne was detected only in Amblyomma lepidum. Ehrlichia species were not detected in any of the tick species examined. Conclusions The results demonstrated the presence of several Anaplasma spp. including the zoonotic A. phagocytophilum and potentially zoonotic A. ovis . Our finding identified potential vectors of A. ovis to be further confirmed. However, an extended study is needed to identify the potential vectors of A. phagocytophilum . The variety of Anaplasma spp. indentified in this study suggests risks of anaplasmosis in animals and humans in the country.