H5N1 Global Scan: Avian Flu Worldwide

Welcome to “H5N1 Global Scan: Avian Flu Worldwide.” Over the past year, avian influenza H5N1 has continued its relentless spread across continents, impacting animal and human health, global trade, and international research efforts.

Let’s start with a continental breakdown. In North America, the United States and Canada have faced persistent outbreaks in poultry and, for the first time, dairy cattle. The Centers for Disease Control and Prevention has logged over 70 human H5 infections since 2024, mostly linked to agricultural exposure, with the first U.S. fatality in Louisiana in early 2025. Canada has reported cases in wild birds and a teenager with severe symptoms, raising concern for new clinical presentations. The Pan American Health Organization notes the Americas have seen more than 76 human cases and over 5,000 outbreaks since 2022.

Europe has reported numerous outbreaks in wild birds, particularly among colony-breeding seabirds in northern regions, with decreasing detection in waterfowl. Human cases here remain rare, often tied to direct contact with poultry. According to the European Centre for Disease Prevention and Control, the risk for the general population is low, but occupational exposure increases vulnerability.

Asia continues to grapple with H5N1, especially in Southeast Asia, where clusters of human infections have occurred in Cambodia, Vietnam, and China—often stemming from direct poultry contact. India and China have each reported fatalities, and genetic analysis highlights ongoing evolution and reassortment in the virus, with multiple clades now emerging, complicating containment.

Africa has intermittent outbreaks, mainly affecting wild birds and poultry, but so far, human cases remain limited.

South America faces virulent animal outbreaks, particularly in Argentina, Chile, and Uruguay, where H5N1 devastated wild bird populations and marine mammals. In Argentina, alarming mortality rates in seal pups were recorded, and Mexico’s first human death occurred this year.

On the international response front, the World Health Organization emphasizes the importance of coordinated surveillance and rapid response, calling global human risk “low to moderate” except for those with direct animal exposure. The Food and Agriculture Organization has stressed cross-agency collaboration, urging countries to strengthen early detection and animal health infrastructure. Meanwhile, the World Organization for Animal Health has catalogued a dramatic increase in mammalian infections, including in cows, foxes, and sea lions, underscoring the virus’s expanding host range.

Cross-border transmission remains a major concern, especially along migratory bird routes, which have contributed to rapid virus spread and challenged regional containment. International trade has felt the impact; countries like Argentina and the Philippines temporarily banned poultry exports during peak outbreaks.

Let’s turn to vaccine development. Several international research initiatives are underway, with phase I and II human vaccine trials advancing in Europe and the United States using mRNA and traditional platforms. Veterinary vaccines have seen broader use, especially in China and parts of Europe for poultry and cattle, but global distribution remains uneven.

Comparing national containment strategies, China, Vietnam, and Cambodia continue aggressive culling and animal movement controls. The United States has prioritized surveillance and targeted culling but is now considering broader livestock vaccination. The European Union has emphasized biosecurity and monitoring, while South American governments focus on rapid response and trade controls. Experts agree that where containment measures are stringent and surveillance robust, outbreaks have been shorter in duration.

In summary, H5N1 remains a...