UK Raises H5N1 Bird Flu Pandemic Risk to Level 4 Amid US Dairy Cattle Outbreak

Jul 26, 2024, 06:42 PM

The UK has raised its pandemic risk assessment of the H5N1 bird flu from level 3 to 4, citing ongoing transmission in US dairy cattle and the potential for the virus to mutate unfavorably. The World Health Organization (WHO) continues to assess the risk to the general public as low but calls on all countries to strengthen influenza surveillance and reporting in animals and humans. Concerns have been raised about the virus maintaining a transmission cycle in cattle, which could create a reservoir for further evolution. Early in vitro data suggest that human seasonal influenza viruses can replicate in bovine cells, raising the possibility of reassortment in cattle. The UK Health Security Agency (UKHSA) has provided an update on the US cattle outbreak in a PDF document.