A comparison of the presence of Theileria ovis by PCR amplification of their SSU rRNA gene in small ruminants from two provinces of Pakistan

Abstract

Objective To compare the presence of Theileria ovis in small ruminants from two provinces of Pakistan and to determine the risk factors associated with the spread of theileriosis. Methods In present study, a total of 210 blood samples were collected from sheep ( n=99) and goats ( n=111) from 5 sampling sites in Punjab (Dera Ghazi Khan, Layyah, Multan and Rahim Yar Khan districts) and Khyber Pukhtoon Khwa (district Kohat) provinces, in Pakistan, from randomly selected herds. Data on the characteristics of the animals (species, gender, age, tick presence or absence, prior treatment for babesiosis) and the herd (location, size, species of animals, dogs associated with the herds, tick burden of dogs associated with the herds) was collected through questionnaires. Results Twelve blood samples (6% of total), 11 from district Kohat, produced the 520 base pairs DNA fragment specific for small subunit ribosomal RNA (ssu rRNA) gene of Theileria ovis, by PCR amplification, of which 11 were sheep and 1 was goat indicating that sheep are more significantly ( P=0.001) prone to this parasite. On the other hand parasite was detected only in 2 out of 210 samples (1%) by blood smear screening confirming PCR as the reliable detection tool. Conclusions PCR is more sensitive and reliable diagnostic tool for detection of Theileria sp. as compared to blood smear screening. Incidence of Theileria ovis is very high in Khyber Pukhtoon Khwa as compared to Punjab province. It was also observed that presence of ticks on animals was the only significant risk factor associated with the theileriosis in small ruminants.