Environmental sampling outperforms bird swabs in live poultry markets

Scientists at Duke-NUS Medical School and collaborators report that environmental sampling in live poultry markets picked up a broader range of poultry viruses than swabbing individual birds alone. In a Nature Communications study based on sampling at two Cambodian live poultry markets from January 2022 through April 2023, researchers used air samples, cage swabs, and poultry wash water alongside chicken and duck swabs, then analyzed them with targeted viral metagenomics. Environmental sampling detected 40 poultry viruses overall, and air from slaughter and holding areas often captured more viral diversity than bird swabs. The team also found highly pathogenic avian influenza H5 clade 2.3.4.4b in environmental samples on multiple visits when concurrent bird swabs were negative. (nature.com)

Why it matters: For veterinary professionals, the study adds evidence that market surveillance programs may miss meaningful pathogen circulation if they rely only on individual-animal sampling. Live poultry markets are well-recognized mixing points for avian influenza viruses and other pathogens, and prior CDC-backed surveillance work in Vietnam, along with earlier reviews and field studies, has already suggested that environmental samples can be efficient, lower-friction tools for detecting avian influenza in these settings. A combined approach, rather than replacing bird testing outright, could improve early warning, biosecurity decision-making, and zoonotic risk assessment. (cdc.gov)

What to watch: Watch for whether animal and public health agencies begin folding routine air, water, and surface sampling into live market surveillance protocols, especially in high-risk avian influenza regions. (nature.com)