Isolation of four serotypes of epizootic hemorrhagic disease virus from Culicoides spp. and their associated infections in cattle in Yunnan, China

Abstract

EHDV is the causative agent of epizootic hemorrhagic disease (EHD), a viral illness with significant implications for animal welfare, society, and the economy. There are reports of EHDV-1, -6, -7, and -10 serotypes isolated from China, but no reports of EHDV-5 strains have been documented. Here, we report the isolation and identification of four serotypes of EHDV (EHDV-1, -5, -6, and -7) from three Culicoides species ( C. tainanus , C. oxystoma , and C. jacobsoni ) collected in Yunnan, China. Phylogenetic analysis revealed that the four strains of EHDV are most closely related to the Australian and Japanese strains. Sero-epidemiological survey results showed that in the border areas of China, Laos, Myanmar, and Vietnam, the rate of EHDV antibody positivity ranged from 29.22% to 58.86%, and seven serotypes of EHDVs circulating among cattle in these regions presented diverse prevalence rates and spatial distributions. This finding indicates that EHDV not only circulates among natural vectors but also infects local domestic cattle in these areas and that the EHDVs prevalent in the Asia-Pacific region may share a common gene pool.