Prevalence of Bovine Viral Diarrhoea infection in cattle and buffaloes from Andhra Pradesh, India

The present study was directed at assessing the prevalence of Bovine Viral Diarrhoea (BVD) in various districts of Andhra Pradesh. Samples from organized cattle and buffalo farms and also from clinical cases were tested from January 2022 to December 2022. A total of 673 serum samples from five organised cattle and buffalo farms and 86 clinical samples from animals suffering from severe diarrhoea, respiratory problems and reproductive disorders were screened for the presence of antibodies against BVD. Serum samples were tested for antibodies against BVD virus p80-125 protein (NSP2-3) using a commercially available competitive ELISA kit (ID Screen). The results revealed that a total of 442 out of 759 animals (58.23 per cent) were positive for antibodies against Bovine viral diarrhoea virus. Statistically significant association was observed between BVD seropositivity and different risk factors such as district, farm, species and breed. Sample size and Geographical location may have contributed to this result. In two organized farms where seropositivity was high (more than 70%), all the seronegative animals (55) were screened for presence of BVD virus using a commercially available BVD p80 antigen ELISA kit (ID screen) to detect persistently infected animals. As no animal was found positive, all the remaining seropositive animals (414) in these two farms were also tested for BVD antigen on the suspicion of a current transient infection or presence of a seropositive PI due to exposure to a BVDV strain that is antigenically different to the persisting strain. All the animals tested were negative for BVD antigen. Out of all the clinical samples tested, one animal that was antibody positive was found positive for BVD virus also, indicating a transient infection. The high seropositivity in the organized cattle farms without a PI animal might either be due to an earlier transient infection in the herd or transfer of a PI animal away from the herd before testing. The high seropositivity in the state and presence of BVD antigen in the field animal indicates that a circulating BVD virus was present in most parts of the state.