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

Abstract

During the 25 months from March 2011 to March 2013, a total of 9,362 medulla oblongata samples collected from dead adult cattle (two years or older) and used for bovine spongiform encephalopathy (BSE) surveillance at 2,203 farms in Iwate Prefecture, Japan. The samples were utilized to investigate the prevalence of bovine viral diarrhea (BVD) in the area. BVD viruses (BVDVs) were detected from 36 cattle (0.38%) on 31 farms (1.41%). A significant difference was observed in each BVDV detection rate of 22 cattle (1.72%) that were two years old at death and 25 dairy farms (1.76%). In comparison to the results of this research, the percentage of genotype 2 in isolated viruses was high (22.2%). These results suggest that monitoring the infection in dairy cattle and the spread of genotype 2 viruses is important for eradication of BVDV in Iwate. It was also concluded that medulla oblongata samples obtained from dead cattle are useful for efficiently investigating BVDV prevalence and epidemiology.