Prevalence of carrier state theileriosis in lactating cows.

Aim: The objective of this study was to examine the carrier status of theileriosis among apparently healthy cross-bred jersey cattle population of Odisha using conventional blood smear examination and polymerase chain reaction (PCR). Materials and Methods: A total of 34 apparently healthy cross-bred Jersey lactating cows were considered in this study. Blood samples were subjected to microscopic examination after staining with Giemsa stain and PCR based molecular diagnosis using two sets of primer, i.e., N516/N517 and TorF1/TorF2 specific for Theileria annulata and Theileria orientalis, respectively. Results: Examination of blood samples revealed presence of theileria parasites to a magnitude of 20.59% for T. annulata, 8.82% for T. orientalis, and 2.94% for both. Conclusion: Molecular diagnosis was found to be much more sensitive than conventional method for diagnosis of theileriosis. T. annulata was found to be the predominant species affecting the exotic cattle. T. orientalis was detected in apparently healthy cows. [ABSTRACT FROM AUTHOR]