Avian influenza overview December 2025–February 2026

Albeit still at high levels after the peak was reached at the beginning of the current reporting period, the weekly number of detections has since been declining. Waterfowl species were affected to a greater extent than in previous years, and more than 90% of detections in poultry were due to primary introduction from wild birds. 

As in previous years, a large number of backyard farms and several zoos were affected. High viral circulation in wild birds resulted in a slight increase in detections in mammals in Europe, with the first potential spillover event from wild birds to dairy cattle suggested in the Netherlands. Between 29 November 2025 and 27 February 2026, 10 cases of avian influenza virus infection were reported in humans (none of which were fatal) in two countries: Cambodia (one A(H5N1) case) and China (eight A(H9N2) cases and one A(H10N3) case). 

Most human cases reported exposure to poultry or a poultry environment prior to detection or onset of illness. The current high level of avian influenza virus circulation in bird populations increases the risk of human exposure to infected animals, although human infections remain rare and no instance of human-to-human transmission has been documented so far. The risk posed by avian A(H5N1) clade 2.3.4.4b influenza viruses currently circulating in Europe remains low for the general public in the European Union/European Economic Area and low-to-moderate for those occupationally or otherwise exposed to infected animals or contaminated environments.