At live bird markets, the risk for avian influenza is higher among workers at large retail markets, women workers, and workers who clean, slaughter, defeather and eviscerate poultry, according to results of a recent meta-analysis.

Xiaoyan Zhou, MD, of the University of Queensland’s School of Veterinary Science, Australia, and colleagues said their findings may help improve infection prevention and control programs at live bird markets (LBMs), where avian influenza (AI) viruses can be maintained and transmitted over long periods of time, according to the researchers.

“After the emergence of [highly pathogenic avian influenza] H5N1 influenza in 2003, several studies have documented that LBMs could be sources of human AI infections,” the researchers wrote in The Journal of Infectious Diseases. “The importance of LBMs in the transmission of AI to humans was also highlighted by the emergence of influenza A (H7N9) viruses of low pathogenicity to poultry in early 2013, causing human infections without preceding or concomitant outbreaks in poultry. Exposure to H7N9-infected poultry at LBMs has been implicated as the main risk factor for human infection.”