Clade 2.3.4.4b of the highly pathogenic avian influenza (HPAI) virus causing outbreaks in wild and domestic birds around the world, continues to spread in dairy cows, poultry and other animals across the United States.

The emergence and broad circulation of highly pathogenic avian influenza (HPAI) H5N1 virus in wild birds and its spillover into dairy cows with sustained transmission in this species pose a major risk to felines.

In a world facing escalating risks from conflict, climate change, and emerging infectious diseases, health systems are the first line of defense for protecting people, economies, and stability.

The unprecedented 2.3.4.4b. A(H5N1) outbreak in dairy cattle, poultry, and spillover to humans in the United States (US) poses a major public health threat.

Situation at a glance On 15 November 2025, WHO was notified of the 71st confirmed human case with influenza A(H5) since early 2024 in the United States of America— the first human case reported in the United States of America since February 2025.

Increase in human H5N1 spillover infections resulting from dissemination of highly pathogenic avian influenza (HPAI) virus into bird and mammal populations raises concerns about HPAI gaining human transmissibility.

ESWI participated in a panel on the One Health approach, together with Spain’s Minister of Health, the EU Health Emergency Preparedness and Response Authority (HERA), Wellcome Trust and HIPRA.

In March 2024, public health agencies in the United States reported highly pathogenic avian influenza (HPAI) virus of subtype A(H5N1) in dairy cattle, with virus detected in milk samples from symptomatic animals.