U.S. bird flu activity for the full year 2025 remained substantial, with USDA APHIS reporting 54.7 million birds affected across more than 600 commercial and backyard outbreaks, alongside 167 confirmed livestock detections. Viral spillover beyond poultry persisted, as USDA confirmed an H5N1 case in a Wisconsin dairy herd was a new wildlife spillover event, distinct from prior cattle transmission. Internationally, Europe ended the year with nearly 700 commercial poultry outbreaks across 23 countries, exceeding totals from recent years and underscoring sustained regional pressure. Asia-Pacific activity continued into winter, with Japan confirming a large commercial outbreak near Tokyo involving roughly 240,000 laying hens. Additional detections across the Americas and Europe, along with trade disruptions and ongoing winter risk, reinforce that HPAI remains firmly entrenched entering 2026.
U.S. Bird Flu In 2025
In 2025, highly pathogenic avian influenza affected approximately 54.7 million birds across 606 commercial and backyard flock outbreaks in the United States, according to USDA APHIS data (United States Department of Agriculture, n.d.-a). In addition, 167 outbreaks were confirmed among livestock during the year (United States Department of Agriculture, n.d.-b). The CDC continues to assess the overall public health risk to humans as low.
USDA APHIS Confirms Wisconsin Dairy H5N1 Case Was a New Wildlife Spillover
USDA APHIS confirmed that the highly pathogenic avian influenza detected in a Wisconsin dairy herd on December 14 represents a new spillover event from wildlife, rather than transmission between cattle or herds. Whole-genome sequencing identified the virus as H5N1 clade 2.3.4.4b genotype D1.1, the same strain linked to earlier dairy detections in Nevada and Arizona, though APHIS said the Wisconsin case is epidemiologically distinct. No additional infected dairy herds have been detected, and the agency stated the finding does not pose a risk to consumer health or the safety of the commercial milk supply (Dall, 2025).
Europe Closes 2025 With Nearly 700 HPAI Outbreaks in Commercial Poultry
Europe ended 2025 with 699 confirmed outbreaks of highly pathogenic avian influenza in commercial poultry across 23 countries, according to European Commission data through December 24, surpassing totals recorded in both 2023 and 2024. Germany reported the highest number of outbreaks, followed by Poland, Hungary, France, and Italy. New farm detections continued through late December across Germany, Italy, Poland, the Netherlands, the United Kingdom, and several other countries, while losses in Italy and Poland alone exceeded several million birds. Wild bird detections also exceeded 2024 levels, with more than 4,100 cases reported in 34 countries, underscoring that there has been no meaningful easing of HPAI activity across the region (Linden, 2025).
Japan Confirms New HPAI Outbreak in Greater Tokyo Area
A commercial poultry facility near Tokyo was hit by highly pathogenic avian influenza on December 30, affecting about 240,000 egg-laying hens, according to Japan’s agriculture ministry. The case marks the first detection in the greater Tokyo area during the current bird flu season, which runs from late fall into the following spring. Movement restrictions and disinfection measures have been imposed at nearby farms, and the ministry said it is dispatching an epidemiological investigation team while urging heightened vigilance nationwide as avian influenza activity continues through the winter (Xinhua, 2025).
Nebraska Loses 144,600 Commercial Birds on Year’s Final Day
USDA APHIS confirmed highly pathogenic avian influenza in a flock of 144,600 commercial laying hens in Butler County on December 31, marking Nebraska’s only commercial poultry detection of 2025 (United States Department of Agriculture, n.d.-a). The state’s previous commercial case occurred on December 30, 2024 (Graber, 2026).
Hong Kong Suspends Poultry Imports From Parts of U.S. and Japan After HPAI Detections
Hong Kong has suspended imports of poultry meat and poultry products from selected regions of the United States and Japan following avian influenza outbreaks, citing public health protection. The ban applies to Lewis County, Washington, and Jessamine County, Kentucky, as well as Ibaraki and Hokkaido prefectures in Japan. Hong Kong authorities said the city imported more than 40,000 tonnes of poultry meat and 2.62 million poultry eggs from the U.S., and smaller but significant volumes from Japan, during the first nine months of 2025. Officials said they are in contact with U.S. and Japanese authorities and will continue monitoring outbreak developments through international animal health reporting channels (Global Ag Media, 2025).
Arkansas Experiencing String of HPAI Outbreaks
Since the last edition of this report on December 19, Arkansas has recorded four new HPAI outbreaks affecting roughly 65,000 birds across both commercial and backyard flocks (United States Department of Agriculture, n.d.-a). Recent cases have been concentrated in southeastern Arkansas, including neighboring Cleveland and Drew counties, reflecting continued regional spread. Arkansas Agriculture Secretary Wes Ward said the pattern is concerning but expected, noting that the state remains vulnerable “for really the next few months” as migratory activity continues, placing the poultry industry on heightened alert (Gay, 2025). While officials emphasized there is no food safety risk to consumers, the outbreaks pose a serious threat to Arkansas’s poultry sector, which generates about $6.7 billion annually in agricultural receipts (Matheson, 2025).
Netherlands Culls 162,000 Chickens After HPAI Outbreak in Deurne
Dutch authorities confirmed highly pathogenic avian influenza at a broiler farm in Deurne on December 28, triggering the culling of 162,000 chickens to contain the outbreak. The site sits amid a dense poultry area, with three farms within one kilometer and seven more within three kilometers, all placed under enhanced monitoring. A 10-kilometer transport ban was imposed around the farm, affecting 46 poultry operations, some already under restrictions due to recent nearby outbreaks. The case adds to continued HPAI activity in the region, where a nationwide poultry housing order has been in effect since October (NL Times, 2025).
H5N1 Detected in Backyard Flocks in Colombia and Brazil
WOAH reported new H5N1 highly pathogenic avian influenza detections in backyard birds in Colombia and Brazil in late December. Colombia confirmed two backyard outbreaks on December 26, affecting flocks of 70 birds in El Reten and 41 birds in Majagual, with deaths reported in both and full depopulation and movement controls implemented; the country has now recorded six backyard outbreaks in the past two months. Brazil reported a December 23 detection in a multi-species backyard flock in Coxipó da Ponte, where 16 of 170 birds died, with laboratory confirmation of H5N1 clade 2.3.4.4b and quarantine and culling measures underway. While the case was limited to a backyard flock, it is notable given Brazil’s role as the world’s largest poultry exporter and its recent declaration of freedom from H5N1 earlier this year (Graber, 2025).
UK Supermarkets Imported Turkeys as Bird Flu Cut Domestic Supply
Several major UK supermarkets sourced limited volumes of European turkeys ahead of Christmas after avian flu reduced domestic production, with Asda, Lidl, and Morrisons stocking small quantities of branded birds from the EU while keeping own-label turkeys British. Industry sources said imported birds accounted for less than 10% of sales and described the move as unusual. The decision followed intensified avian flu activity after the current outbreak season began in October, which led to the culling of roughly 300,000 Christmas poultry birds, or more than 5% of the seasonal flock. According to Will Raw, chair of the National Farmers’ Union’s national poultry board, widespread shortages did not materialize despite the outbreak (Partridge & Butler, 2025).
References
Dall, C. (2025, December 22). Center for Infectious Disease Research and Policy. Umn.edu. https://www.cidrap.umn.edu/avian-influenza-bird-flu/usda-says-h5-avian-flu-detection-wisconsin-dairy-herd-new-spillover-event
Gay, C. (2025, December 24). Avian flu cases in Arkansas rise to six, affecting commercial and backyard flocks alike. KATV. https://katv.com/news/local/avian-flu-cases-in-arkansas-rise-to-six-affecting-commercial-and-backyard-flocks-alike-katv-news-share-inform-public-community
Global Ag Media. (2025). Hong Kong halts poultry imports from US, Japan. Thepoultrysite.com. https://www.thepoultrysite.com/news/2025/12/hong-kong-halts-poultry-imports-from-us-japan
Graber, R. (2025, December 29). Avian flu reported in Brazil, Colombia backyard birds. WATTPoultry.com. https://www.wattagnet.com/poultry-meat/diseases-health/avian-influenza/news/15774875/avian-flu-reported-in-brazil-colombia-backyard-birds
Graber, R. (2026, January 2). Nebraska layer flock hit by HPAI on last day of 2025. WATTPoultry.com. https://www.wattagnet.com/poultry-meat/diseases-health/avian-influenza/news/15775035/nebraska-layer-flock-hit-by-hpai-on-last-day-of-2025
Linden, J. (2025, December 30). Europe ends 2025 with more than 700 avian flu outbreaks. WATTPoultry.com. https://www.wattagnet.com/poultry-meat/diseases-health/avian-influenza/news/15774950/europe-ends-2025-with-more-than-700-avian-flu-outbreaks
Matheson, L. (2025, December 20). Third Bird Flu Case Confirmed at Cleveland County Poultry Farm as Arkansas Officials Urge Vigilance - Deltaplex News. Deltaplex News. https://www.deltaplexnews.com/local-news/third-bird-flu-case-confirmed-at-cleveland-county-poultry-farm-as-arkansas-officials-urge-vigilance/
NL Times. (2025, December 28). 162,000 chickens culled after bird flu outbreak at Deurne broiler farm. NL Times. https://nltimes.nl/2025/12/28/162000-chickens-culled-bird-flu-outbreak-deurne-broiler-farm
Partridge, J., & Butler, S. (2025, December 21). UK supermarkets turn to European turkeys as avian flu hits supply. The Guardian; The Guardian. https://www.theguardian.com/business/2025/dec/21/uk-supermarkets-european-turkeys-avian-flu-hits-supply-christmas
United States Department of Agriculture. (n.d.-a). HPAI Confirmations in Commercial and Backyard Flocks. Www.aphis.usda.gov. https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/commercial-backyard-flocks
United States Department of Agriculture. (n.d.-b). HPAI Confirmed Cases in Livestock | Animal and Plant Health Inspection Service. Www.aphis.usda.gov. https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/hpai-confirmed-cases-livestock
Xinhua. (2025). Japan confirms season’s 1st bird flu outbreak in greater Tokyo area. News.cn. https://english.news.cn/20251230/11981e3a0d964657ae701ffdda13caee/c.html