Prevalence of infectious bursal disease in chicken populations in China during 1983–2024: a meta-analysis

Importance: Infectious bursal disease (IBD) is an acute, highly contagious and immunosuppressive disease caused by the Infectious bursal disease virus (IBDV), which has brought significant economic losses to China's chicken industry. This meta-analysis aimed to evaluate the prevalence of IBD among in chicken populations across mainland China. Methods: A total of 32 studies on infectious bursal disease virus in China were identified through a comprehensive search of six major databases: PubMed, Google Scholar, Cochrane Library, VIP, China National Knowledge Infrastructure (CNKI), and Wanfang. These publications, spanning 1983-2024, were used to estimate the prevalence of infectious bursal disease in chicken populations. Based on predefined exclusion criteria studies were excluded if they were duplicates, involved non-chicken hosts, or lacked sufficient data to calculate prevalence rates in chickens in mainland China. Relevant data were then extracted from the remaining studies that provided estimates of IBDV infection prevalence in chicken populations across the region. Results: A total of 32 studies encompassing data from 210,983 chickens met the study criteria for analysis. The pooled prevalence of infectious bursal disease infection was estimated at 37% (95% CI: 29-46). The prevalence in Northwest China was significantly higher, reaching 88% (95% CI: 85-91), considerably exceeding rates observed in other regions. The prevalence of IBDV infection was associated with the region, type, growth stage, scale, published time, season, and detection method. Conclusion: The prevalence of IBD displays clear seasonal and regional patterns. Therefore, ongoing surveillance of IBDV and the development of targeted control measures tailored to specific conditions are essential. Further, effective and well-coordinated interventions are crucial to limiting the spread of IBDV among chicken populations, particularly during periods of low temperature and favorable humidity, when transmission risk is high. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD420261296958, identifier: CRD420261296958.