Welcome to H5N1 Global Scan: Avian Flu Worldwide. I’m your host, and today we’re exploring the unprecedented spread and global impact of H5N1 avian influenza, tracing its path continent by continent, examining research and response, and asking what’s next.

Since 2020, highly pathogenic H5N1 has surged across the globe. According to the World Health Organization, as of late 2025, outbreaks have hit every continent except Australia, with hundreds of millions of birds culled and wildlife decimated. In North and South America, vast die-offs of seabirds and marine mammals have alarmed conservationists, while the US and Canada have reported both animal and human infections. Europe has seen repeated mass culls, such as Germany’s culling of over 500,000 birds following widespread outbreaks. Asia faces constant challenges, with countries like China and Cambodia recording both poultry and human deaths, and India and Vietnam reporting severe cases as well. Even Antarctica recorded its first outbreak in late 2023, threatening local wildlife with catastrophic breeding losses. In Africa, sustained outbreaks threaten food security and livelihoods, especially where poultry farming is vital.

The Food and Agriculture Organization reports nearly a thousand avian flu outbreaks in 38 countries since September, mostly driven by the H5N1 2.3.4.4b clade, which is increasingly infecting new species, including mammals. The Centers for Disease Control and Prevention notes that in the US alone, H5N1 human cases reached 70 by mid-2025, many linked to dairy and poultry workers. Notably, most cases were mild, yet one death was recorded, and monitoring focuses on lack of known sustained human-to-human spread.

Globally coordinated research has accelerated. The World Health Organization and FAO stress that the virus’s ongoing evolution and jump into mammals—including cattle and marine animals— increases the risk of reassortment, highlighting the need for vigilant surveillance. Ongoing international research projects track genetic shifts and pathogenicity. The CDC and European agencies recently identified high viral loads in raw milk and mammary tissue, prompting new regulations around food safety and animal testing.

WHO and FAO statements underscore that while the immediate public health risk remains low, the pandemic threat persists. Both organizations call for urgent international cooperation on surveillance, data sharing, and rapid response. The OIE coordinates cross-border communication to manage outbreaks affecting trade and animal movement, critical as the virus respects no borders.

Trade impacts have been widespread. The suspension of poultry and egg exports has affected countries in South America, Asia, and Europe, contributing to food price spikes and shortages—such as 20 million chickens culled in the US late last year, leading to an egg shortage. Countries frequently ban imports from affected regions to stem risk, complicating supply chains.

Global vaccine development has accelerated, with both animal and potential human vaccines in clinical testing. Vaccine strategies differ: China and several European countries have rolled out targeted poultry vaccination, while North America relies on mass culling and movement restrictions. Some Southeast Asian nations combine vaccination with robust community surveillance.

Comparing national responses, China enforces strict farm biosecurity and rapid animal vaccination. The US emphasizes surveillance and culling, while the EU uses a mix of culling, trade restrictions, and targeted vaccination in high-risk zones. Resource-limited states, especially in Africa and parts of Asia, face ongoing challenges around vaccine access and outbreak detection.

H5N1’s expansion across continents and species makes pandemic preparedness an urgent international priority. As the world watches the boundaries between animal and human health...