Indian Journal of Comparative Microbiology, Immunology and Infectious Diseases

Bovine viral disease (BVD) is a common viral disease of cattle, sheep, and other even-toed ungulates, which is caused by bovine viral diarrhea virus (BVDV), a member of Pestivirus under the family Flaviviridae. Bovine viral diarrhea virus (BVDV) has a worldwide distribution, and due to its economic importance, BVD is listed by OIE as a priority cattle disease for international trade. Most of the studies based on antibody detection have shown that the prevalence of infected herds is in the range of 70-100%. A few of the studies indicating the number of persistently infected (PI) animals have found 1-2% of cattle as PI animals. In India, the first serological evidence of this disease was reported from Odisha in 1982. Thereafter, a prevalence of 43.56% in cattle and buffaloes from Gujarat was reported in 1989; an overall prevalence of 17.31% (76/439) in cattle and buffaloes from 17 states was reported in 1999; an overall prevalence of 30% of BVDV antibody in Indian cattle and buffaloes from 14 states was reported in 2007; and the prevalence of 24.7% in the smallholder system in Trichur district, Kerala, was reported in 2015. Confirmatory evidence of BVD in India has been confirmed through molecular methods in cattle in 2004 as well as 2011, buffaloes in 2008, goats in 2007 as well as 2012, sheep in 2012, and Himalayan yaks in 2007. Acute clinical forms of BVD, including mucosal disease, have not yet been reported in India so far. However, seroprevalence of BVD was detected in samples randomly collected from different parts of the country. The widespread importation of Holstein cattle from North America may have contributed to the predominance of BVDV and BVDV 1b in India. Most probably, the importation of fetal calf serum from America and European countries for vaccine production and immunization of cattle, and the introduction of exotic germplasm either through livestock trade or semen importation for crossbreeding programs to reinforce livestock production during the last four decades, may have introduced BVD into India. BVDV type-1 has also been detected in goats, sheep, and Himalayan yaks as well. Since crossbreeding of domesticated yaks and hill cattle has been practiced for several years for increasing draught power and milk yield, hence the historical and present contact between yaks and cattle is presumable. It is also possible that the infection might have been transmitted from Tibet, China, Nepal, or Bhutan due to traditional links of yak breeders in India with these countries. This review describes the current status of BVDV, its epidemiology, genomic structure, and antigenic typing.