Prevalence of theileriosis in cross-bred cattle: its detection through blood smear examination and polymerase chain reaction in Dehradun district, Uttarakhand, India

Abstract

Aim: Theileriosis is a major threat to dairy and related industries. Theileria is a protozoan parasite that causes theileriosis, a fatal disease. The aim of the present study was to assess the prevalence of theileriosis in crossbred cattle belonging to Dehradun district, Uttarakhand, India. Materials and Methods: We screened 301 blood samples each month from apparently normal/healthy crossbred cattle from various locations of Dehradun district. Samples were tested using Giemsa's staining technique and specific PCR test. Result: Microscopic examination of blood smears revealed 27.2% (82) overall prevalence of theileriosis. The highest prevalence was found in rainy season with a prevalence rate 45.4%. By Theileria genus specific PCR test, 98 samples (32.5 %) were found to be positive for theileriosis. Conclusion: Our study suggests that theileriosis is spreading to even the temperate region in Uttarakhand and immediate screening norms/policies are needed to reduce the extent of spread. There is a need for further investigation using molecular technique.

Keywords

• blood smear
• PCR
• seasonal prevalence
• Theileria