Effectiveness of market-level biosecurity at reducing exposure of poultry and humans to avian influenza: A systematic review and meta-analysis

Background. In this study, we aimed to identify the effect of market-level risk factors on avian influenza (AI) infection in poultry and humans and generate evidence that will inform AI prevention and control programs at live bird markets (LBMs). Methods. We performed a systematic literature review in both English and Chinese search engines. We estimated the pooled odds ratios of biosecurity indicators relating to AI infections at market level using a quality effects (QE) meta-analysis model. Results. Biosecurity measures effective at reducing AI market contamination and poultry infection at LBMs include smaller market size, selling single poultry species and separating different species, performing cleaning and disinfection and market closures, ban on overnight storage, and sourcing poultry from local areas. Our meta-analysis indicates that higher risk of exposure to AI infection occurs in workers at retail LBMs, female workers, and those who contact ducks, conduct cleaning, slaughtering, defeathering, or evisceration. Conclusions. The most effective strategies to reduce AI market contamination identified in this study should target larger LBMs that are located at noncentral city areas and sell and slaughter multispecies of live poultry. Live bird market workers directly involved in cleaning and poultry processing tasks should participate in occupational health and safety programs.