Epidemiology and molecular characterization of Theileria annulata in ticks collected from cattle in the central part of Tamil Nadu, India

Tick-borne diseases are the most common in cattle in the tropical and subtropical regions of India and lead to substantial economic losses to small and marginal farmers. This study aimed to identify the diverse species of ticks infesting cattle in the central part of Tamil Nadu, India, and to assess the prevalence of Theileria annulata infection in various species of ticks through PCR. Out of 123 cross-bred and 105 native breed cattle examined for tick infestation, 40 (18%) and 29 (12.7%) cattle were infested with Ixodid ticks, respectively. The most prevalent tick species identified was Rhipicephalus microplus ( n =589), followed by Hyalomma anatolicum ( n =532), Hyalomma marginatum ( n =145), Haemaphysalis intermedia ( n =79), and Rhipicephalus haemophysaloides ( n =1) found in the study area. The prevalence and intensity of the tick infestation were found to be higher in cross-bred (71.04%) than native breed cattle (28.96%), and there was no significant difference between the studied breeds (chi-square value =24; df =20; p value =0.24) was observed. However, a significant difference in the H. anatolicum tick infestation was observed between the Cauvery Delta (14.30%) and the North-Western (20%) zones of Tamil Nadu ( p