Surveillance of Bovine Viral Diarrhea Virus Infection in Dead Cattle in Iwate Prefecture

Endemic infections of bovine viral diarrhea virus genotypes 1b and 2a isolated from cattle in Japan between 2014 and 2020

“…According to a Japanese survey of PI animals in dairy farms located in Kanto and westward regions, the proportion of farms with PI was 7.6%, and the proportion of cattle tested as PI was 0.12% [10]. Other groups reported that the proportion of PI in dairy and beef farms in the Tohoku region was 0.38% [6], and that in beef farms in the Kyushu region was 0.18% [2]. Although the annual number of BVD diagnoses that are mandated to be notified to the government was approximately 300−400 over the last five years [17], it is suggested that a large number of hidden PIs exist in Japan because their estimated number are calculated at more than 4,500 from the reported proportion (0.12%) [10] and total number of cattle in Japan (approximately 3.9 million head in 2020) [21].…”