Avian influenza overview June–September 2025

Between 7 June and 5 September 2025, 183 highly pathogenic avian influenza (HPAI) A(H5) virus detections were reported in domestic (27) and wild (156) birds across 15 countries in Europe. Although HPAI A(H5N1) virus detections were predominant in western and southwestern Europe, they also occurred on the northernmost coast of Norway. More than 75% of the detections in wild birds related to colony-breeding seabirds, particularly European herring gulls, while the number of detections in waterfowl decreased compared to the previous months. Less poultry establishments were affected during the current reporting period, with no secondary spread occurring. Regarding mammals in Europe, HPAI A(H5N5) virus detections were reported in four Arctic foxes in Norway. In the United States of America (USA), the number of HPAI A(H5N1) virus detections in dairy cattle stagnated, while the muskrat and round-tailed ground squirrel were reportedly affected for the first time. Between 7 June and 8 September 2025, 19 cases of avian influenza virus infection in humans, including three deaths, were reported in four countries: Bangladesh (one A(H5N1) case), Cambodia (11 A(H5N1) cases), China (one A(H10N3), five A(H9N2) cases) and India (one A(H5N1) case). Most of the A(H5N1) human cases (<i>n</i> = 12/13) reported exposure to poultry prior to detection or onset of illness. Given the widespread circulation of avian influenza viruses in animal populations, human infections remain rare. No human-to-human transmission was documented during the reporting period. The risk of infection with the avian A(H5) clade 2.3.4.4b influenza viruses currently circulating in Europe remains low for the general public in the European Union/European Economic Area (EU/EEA) and low-to-moderate for those occupationally or otherwise exposed to infected animals or contaminated environments.