Prevalence and Risk Factors of Mycoplasma Hyopneumoniae in Swine Farms, Mainland China, 2003–2024: A Meta-Analysis

This is the first systematic review and meta-analysis on the prevalence and risk factors of M. hyopneumoniae infection in swine farms across mainland China from 2003 to 2024. A total of 54 eligible cross-sectional studies were analyzed by stratifying farms as subclinically or clinically infected. The overall pooled prevalence of M. hyopneumoniae was estimated as 33.4%, with clinical infection farms showing a significantly higher prevalence (52.9%) than subclinical farms (11.5%). Subgroup analyses revealed significant variations in infection rates based on age, sampling year, geographic region, farming scale, season, sampling type, and diagnostic method. Small-scale farms, farms with breeding swine, and farms in the Northwest region showed the highest infection rates. Diagnostic methods and sampling types also significantly influenced detection rates. Sensitivity analyses confirmed the robustness of the results, while publication bias was addressed using the Trim-and-Fill method. To effectively reduce the burden of M. hyopneumoniae in the swine industry in mainland China, future efforts should prioritize enhanced biosecurity, improved diagnostic accuracy, and region-specific vaccination and management strategies.