Active surveillance for emerging influenza A viruses – findings from a one health study in Vietnam’s live bird markets

The 2025 study by Bui and colleagues reports on active, periodic surveillance of influenza A viruses (AIVs) at live bird markets (LBMs) in northern Vietnam — a region and context recognized as high-risk for zoonotic influenza emergence. The authors examined avian, environmental and human-related samples collected between July 2021 and August 2023 across five LBMs, to assess the diversity and prevalence of AIV subtypes in this “One Health” framework. Objectives and Rationale The study seeks to address the persistent threat posed by avian influenza viruses at the human–animal interface. LBMs — where live poultry from different farms and species are brought together under crowded, sometimes unsanitary conditions — have repeatedly been identified as hotspots for AIV amplification, co-circulation, and potential spillover to humans. The authors argue that systematic active surveillance (rather than passive outbreak reporting) is vital for early detection of emerging influenza A subtypes, offering an opportunity to monitor subtype diversity...