Avian influenza activity declines across Europe as spring ends

Highly pathogenic avian influenza (HPAI) activity continued to ease across Europe during spring 2026, with detections expected to remain at low levels over the summer, according to the latest quarterly report from the European Food Safety Authority (EFSA), the European Centre for Disease Prevention and Control (ECDC) and the European Union Reference Laboratory for Avian Influenza (EURL).

Between 28 February and 4 June 2026, European countries reported 186 HPAI outbreaks in poultry and captive birds, together with 763 detections in wild birds. While the number of outbreaks in domestic birds remained comparable to the same period in 2025, detections in wild birds were more than three times higher, reflecting the intense circulation of HPAI viruses among waterfowl during the past epidemiological season.

Distribution of the number of HPAI virus detections in wild birds (cumulative number n = 19,694) (pink) and establishments keeping domestic birds (cumulative n = 8097) (blue) reported in Europe during seven epidemiological years by month of suspicion, from 1 October 2019 to 4 June 2026 (total n = 27,791). Note: United Kingdom data are from the Animal Disease Notification System (ADNS, former ADIS) up until 31 December 2020. From 1 January 2021 onwards, the data source was WOAH-WAHIS for the United Kingdom (excluding Northern Ireland) and ADNS/ADIS for the United Kingdom (Northern Ireland)5. a If the date of suspicion was not available, the date of confirmation was used to assign the week of suspicion. Source: ADNS/ADIS and WOAH-WAHIS (data extraction carried out on 4 June 2026).

Despite that high level of viral circulation during the winter, the number of detections in mammals remained low. Red foxes were the species most frequently affected within the European Union, while, outside the EU, H5N5 virus was detected in a polar bear and a walrus in Norway. Overall, mammalian detections remained low compared with the number of avian outbreaks recorded during the winter season.

Most poultry outbreaks reported during the period occurred in Poland, where repeated virus introductions combined with secondary spread contributed to disease persistence. In most other European countries, outbreaks were linked primarily to direct or indirect contact with infected wild birds. France continued to report sporadic HPAI outbreaks in vaccinated duck flocks, although at lower levels than in previous reporting periods. Chickens, particularly laying hens and breeders, were the poultry categories most frequently affected.

Number of poultry heads in the HPAI-affected establishments per country (total n = 6,534,773; countries are ranked according to the number of poultry heads affected) . Source: ADIS, EFSA and WOAH-WAHIS (data extraction carried out on 4 June 2026).

Another notable finding was the first European detection of low pathogenic avian influenza (LPAI) H9N2 virus belonging to clade G5.5. The virus was identified in April in seven establishments keeping broiler chickens within a single settlement in Hungary. Increased mortality in one establishment initially raised suspicions of HPAI, but laboratory investigations instead confirmed H9N2 together with infectious bronchitis virus, indicating a co-infection. The source of introduction could not be determined, and all affected establishments were depopulated before cleaning and disinfection, with follow-up testing planned after repopulation.

Geographic distribution, based on available geocoordinates, of HPAI virus detections in poultry and captive birds (186), reported by virus subtype in Europe from 28 February to 4 June 2026. * This designation is without prejudice to positions on status and is in line with United Nations Security Council Resolution 1244 and the International Court of Justice Opinion on the Kosovo Declaration of Independence. Source: ADIS and WOAH-WAHIS (data extraction carried out on 4 June 2026).

Although H9N2 viruses have previously been detected in Europe, this is the first report involving clade G5.5, a lineage that has also been associated with sporadic human infections in the Middle East and West Africa. EFSA and ECDC recommend continued surveillance to monitor any further spread of the virus.

The public health assessment remains unchanged. Human infections continue to be rare, with no evidence of sustained person-to-person transmission. The risk for the general public in the EU and EEA is considered low, while people with occupational exposure to infected birds or contaminated environments continue to face a low-to-moderate level of risk.


Also read: EFSA annual report on avian influenza
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