Global H5N1 Bird Flu Surge Continues Worldwide With Sharp Increases in North America and Europe in 2025

This is Avian Flu Watch: Global H5N1 Tracker. Today we bring you the latest on the global spread of bird flu, focusing on data-driven insights as of September 22, 2025. Since late July, the Food and Agriculture Organization has reported 249 new high pathogenic avian influenza outbreaks in animals across five continents, with the H5N1 subtype at the center of concern. Notably, 139 of these outbreaks were attributed to H5N1, with significant activity in North America and Europe. The United States remains the single largest hotspot, logging 3579 H5N1-related events since October 2024. Canada has reported 134 incidents, while the UK has seen 716 outbreaks, and France reported 18. In Asia, Vietnam, Cambodia, and China have reported steady, though lower, numbers, with 18, 27, and 42 outbreaks respectively in the past several months. In South America, Argentina and Brazil together account for 23 animal outbreaks, mainly in poultry and wild birds. On the human side, only two new H5N1 human infection events have been officially confirmed since late July. Vietnam also reported a severe case involving encephalitis in April, underscoring the risk of neurological complications in rare zoonotic transmission. Recent global trend lines show a seasonal spike starting in mid-2025, with North America and Western Europe experiencing the sharpest increases. The map visualization would show deepening clusters in the US Midwest, the British Isles, France’s western coast, and sporadic new dots across Southeast Asia and Southern Africa. Compared with last year, H5N1 activity is up 18 percent globally. In the United States, case numbers have doubled compared to the previous 12-month period, while Spain and Norway report a four-fold increase in outbreaks among wild and domestic birds. However, thanks to aggressive surveillance and culling measures, Belgium and Hungary have managed to cut outbreak rates by over 40 percent since spring. Cross-border transmission continues to challenge control. Genetic analyses highlight how H5N1 strains in Egypt, Israel, Turkey, and Lebanon exhibit close ties, underscoring virus migration along major bird flyways and occasional human–animal passages. The US and Canada saw rapid spread between commercial and wild populations, especially in border states, suggesting migratory waterfowl and live animal trade as conduits. Clade 2.3.4.4b is now the preeminent variant globally, with new genetic reassortments occasionally surfacing. Health agencies are alert for reports of mammalian infections—recent H5N1 spillovers in cats and cattle in North America have not yet translated into sustained transmission, but remain under close watch. Internationally, several containment successes stand out. The United Kingdom’s localized “ring culling” around major poultry premises was effective in halting eastward spread. Argentina’s early detection campaign has largely kept H5N1 cases out of commercial poultry zones. Yet, failure to rapidly control wild bir This content was created in partnership and with the help of Artificial Intelligence AI.