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.

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.

The global spread of highly pathogenic avian influenza A(H5N1) viruses poses a serious pandemic threat.

The emergence of highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b in U.S. dairy cattle highlights the urgent need to understand transmission dynamics within and among farms.

Birds operate at body temperatures several degrees higher than those of mammals, and, like mammals, birds are infected by influenza viruses.