Bluetongue infection rate in mithun (Bos frontalis) in the north-eastern upland region of India.

Studies conducted on 106 mithun at the National Research Centre on Mithun and 66 free-ranging mithun in Nagaland, India, revealed an infection rate with bluetongue virus of 86%, using a commercially available competitive enzyme-linked immunosorbent assay. Animals were grouped according to their age: 36 of 1 to 2 years of age, 50 of 2 to 4 years of age and 86 aged 4 years and over. The highest infection rate (98%) was found in mithun > 4 years old and the lowest (58%) in those 1 to 2 years old. No statistically significant difference was observed between infection rates of males (89%) and females (85%). The infection rate was higher (95%) in free-ranging mithun than in mithun kept under a semi-intensive system (80%). This is the first report of serological evidence of antibodies to bluetongue virus in mithun. The possible role of vectors in the epidemiology of bluetongue virus infection in mithun is discussed briefly.