Molecular epidemiology, seroprevalence and genetic characterization of bovine rotavirus in Qinghai yaks: first identification of G6P[5] genotype.

Bovine Rotavirus (BRV) is the main pathogen responsible for viral diarrhea in calves, which has a serious impact on the cattle industry and leads to economic losses. Therefore, this study aimed to fill the gap in the epidemiological research of yak-sourced rotavirus in Qinghai Province by investigating the infection rate and antibody positive rate of BRVA from yaks in Qinghai Province. We collected a total of 1,195 yak anal swab samples, 95 diarrheal fecal samples, and 834 serum samples from various cities and prefectures in Qinghai Province. The TaqMan probe method and indirect ELISA assay were used to detect and comprehensively analyze the infection rate of BRVA and the positive rate of serum antibodies in different cities and prefectures of Qinghai Province. Additionally, the key factors influencing virus transmission were explored in combination with epidemiological characteristics. The results showed that BRVA infections occurred to varying degrees in Xining City, Haidong City, Haibei Tibetan Autonomous Prefecture, Huangnan Tibetan Autonomous Prefecture, and Haixi Mongolian and Tibetan Autonomous Prefecture. The dominant genotype G6P[5] of the BRVA strains was first identified from yak populations in Qinghai Province. A total of 766 positive sera were detected by indirect ELISA, with an overall antibody positive rate of 91.85%. This study not only provided the latest epidemiological data of bovine rotavirus from yak populations in Qinghai Province, but more importantly, offered crucial data support for formulating targeted prevention and control strategies against BRVA in this region.