Avian Flu Watch: Global H5N1 Tracker

Welcome to Avian Flu Watch, your data-driven update on the global spread of H5N1 avian influenza. Today, we focus on worldwide case trends, geographic hotspots, comparative statistics, cross-border transmission, and what recent data suggests about containment, emerging variants, and traveler safety.

As of November 2025, H5N1 is actively circulating on every continent except Australia. Globally, the World Health Organization reports 990 confirmed human cases since 2003, resulting in 475 deaths—a fatality rate of 48 percent. Since 2022, the Americas alone have experienced over 5,000 outbreaks, with 76 human infections and two deaths, according to the Pan American Health Organization.

Hotspots are shifting but show clear clustering. In North America, the United States is a focal point, with around 70 officially reported human cases and significant livestock impact. California leads by case volume due to large dairy herds, as confirmed by CDC and mathematical modeling published in Nature’s November 2025 edition. In the last quarter of 2024, authorities culled 20 million chickens, resulting in nationwide egg shortages.

Recent modeling shows the highest disease burden in US West Coast states—California, Texas, and neighboring regions—reflecting large herd sizes and frequent livestock movement. Arizona and Wisconsin are flagged as high-risk for new outbreaks. Canada saw its first teenage patient in November 2024, while Mexico and India have each confirmed fatal pediatric cases in 2025. In Europe, Germany and Hungary combat outbreaks among cranes and poultry, with Germany reporting over 100 farm-level outbreaks and culling more than half a million birds.

South America faces a severe cascade among wildlife. Argentina, Chile, and Uruguay have lost nearly 600,000 wild birds and 50,000 mammals to H5N1 since 2022. Marine mammals are not spared: outbreaks have killed thousands of seals, sea lions, and devastatingly, up to 70 percent of Southern elephant seal pups at certain breeding sites.

Visualizing these trends, data curves for outbreaks show steady rises since mid-2022, peaking in poultry-dense regions and shifting toward mammals and humans in late 2024 and 2025. Time series data highlights seasonal surges—particularly in colder months—and a widening geographic spread into new territories. Compare these lines, and you see rapid escalation in North and South America with slower but persistent case counts in Europe and parts of Asia.

Cross-border transmission remains closely tied to wildlife migration and agricultural trade. Studies published in the Journal of Global Health highlight the role of migratory bird flyways connecting East Asia, Siberia, and Oceania. Evidence from live poultry market surveillance in China links virus introduction to these routes, while global livestock trade helps move the virus between commercial operations in North America and Europe.

International responses vary. Notable successes include rapid containment following outbreaks in the Philippines, which banned poultry exports and implemented local culls. However, in the US, delayed federal intervention has blunted but not stopped dairy outbreaks. Mexico and India are still scaling human surveillance after pediatric deaths. Europe’s coordinated culling and veterinary monitoring have curbed spread in parts of Germany and Hungary, but spotty enforcement persists elsewhere.

Variants of concern are emerging—most notably clade 2.3.4.4b, which dominates recent outbreaks. However, Southeast Asia has seen new reassortant viruses combining genetic material from multiple lineages. This could affect transmissibility and severity, underscoring the need for genomics-based monitoring.

For travelers, advisories center on avoiding direct contact with birds, especially in markets and farms, and adhering to biosecurity measures....