A PCR-based survey of selected Babesia and Theileria parasites in cattle in Sri Lanka

Abstract

Hemoprotozoan parasites are responsible for significant economic losses in cattle. We screened Sri Lankan cattle populations for the presence of Babesia bovis, Babesia bigemina, Theileria annulata, and Theileria orientalis, using species-specific PCR assays. Out of 316 samples collected from animals in four different districts of Sri Lanka (Nuwara Eliya, Polonnaruwa, Ampara, and Jaffna), 231 (73.1%) were positive for at least one parasite species. All four parasite species were detected among the study groups from all of the districts surveyed. The first and second commonest hemoprotozoan parasites identified were T. orientalis (53.5%) and B. bigemina (30.1%), respectively. We found that the dry zones (Polonnaruwa, Ampara, and Jaffna) had more Babesia-positive animals than the hill country wet zone (Nuwara Eliya). In contrast, T. orientalis was the predominant species detected in Nuwara Eliya, while infection with T. annulata was more common in the dry zones. In addition, 81 (35.1%) of the 231 positive samples were infected with more than one parasite species. The presence of multiple parasite species among the different cattle populations is of clinical and economic significance. Therefore, island-wide control and prevention programs against bovine babesiosis and theileriosis are needed to minimize the financial burden caused by these parasites.