Prevalence of Bovine Herpes Virus 1 in Yaks (Bos grunniens) from the Qinghai-Tibetan Plateau in China: A Meta-analysis

Bovine herpesvirus 1 (BHV-1) is a virus capable of causing serious respiratory distress in yaks, and it can further result in reproductive diseases and late-term abortions. In this article, we conducted a systematic meta-analysis aimed at exploring BHV-1 prevalence in yaks of the Chinese Qinghai-Tibetan Plateau (QTP). To complete this analysis, we identified all relevant articles on this topic in both English and Chinese literature databases published through March 20, 2020. Studies were not included in this analysis if they were reviews, repeats of previous studies, included inconsistent or incomplete data, nonyaks study, or provided solely prevalence data. Using the identified studies, we were able to determine the number of BHV-1-infected yaks in the QTP, and to calculate the pooled prevalence. We ultimately identified 16 relevant studies (5737 total yaks), with a pooled BHV-1 infection prevalence rate of 38%, with the highest prevalence in Sichuan province and the lowest in Gansu province (58% and 18%, respectively). We found BHV-1 prevalence to be associated with both test time and method. Together, our results suggest that BHV-1 infections in yaks are becoming an increasingly widespread and serious concern. As such, it is essential that this prevalence continue to be monitored, and that effective regulatory efforts be implemented in order to prevent the continued spread of this disease.