Foot-and-mouth disease in mithun, yak, cattle-yak hybrids and cattle in the north-eastern states of India during 2021-2022

During 2021, relatively higher numbers of foot and mouth disease (FMD) outbreaks were reported in the bovine population compared to preceding years along with reports in mithun and cattle in few states of north-eastern regions of India. FMD virus (FMDV) serotype was identified using sandwich ELISA and RT-multiplex PCR on clinical samples from cattle (n = 5) and mithun (n = 11) of Arunachal Pradesh and Nagaland. The tests revealed that 2 samples from mithun and 1 sample from cattle were found positive for FMDV serotype O. Two samples from suspected FMD in mithun from an organized farm in Nagaland were tested positive for serotype A. Serum samples collected at random and tested using 3AB3 nonstructural protein ELISA revealed a higher FMDV NSP antibody prevalence in cattle-yak hybrids (16.7%), followed by mithun (10.6%) and yak (3.8%). Mithun and yak being semi-domesticated species mingle with cattle and such close proximity in common habitats and grazing areas might have caused the spread of infection. Furthermore, because of their habitat in forests, yak and mithuns are generally not vaccinated against FMD. The disease in cattle, buffalo and semi-domesticated populations of mithun and yak as well as their hybrids in hilly north-eastern parts of India is of high concern. These species need to be vaccinated biannually and monitored for protective antibody status against FMD.