In autumn 2025, there has been an unprecedented increase in the detection of highly pathogenic avian influenza A(H5N1) virus in wild birds in Europe. Between 6 September and 14 November, 1 443 cases were recorded in 26 European countries, a fourfold increase compared to the same period in 2024. Most of the cases were caused by a new variant of the A(H5N1) subtype, which is spreading rapidly. At the same time, the number of outbreaks in domestic poultry has increased significantly in the affected areas, with outbreaks reported daily in some countries. The virus is spread mainly by the migration of wild birds, but also indirectly via contaminated objects. The virus can survive for weeks or months in cold and damp environments. This evolution increases the risk of human exposure to avian influenza virus.