H5N1 public health risk currently low: joint assessment

GENEVA - The global public health risk of influenza A (H5N1) viruses is currently low, with infection risks for occupationally exposed groups ranging from low to moderate, according to a joint assessment released here Friday.

The World Health Organization (WHO), in collaboration with the Food and Agriculture Organization (FAO) and the World Organization for Animal Health (WOAH), released the updated assessment.

The assessment, based on data through Dec. 18, highlights that human infections primarily result from contact with infected animals or contaminated environments. Despite an increase in cases, the total number remains low, with no significant impact on global public health. However, animal-to-animal transmission persists, particularly in regions lacking effective preventive measures, which places farm workers and others in contact with infected animals at variable risk, depending on local conditions and control efforts.

During a Dec. 17 press briefing in Geneva, WHO, FAO, and WOAH experts detailed the global H5N1 situation and warned about the virus's potential evolution. Maria Van Kerkhove, WHO's expert on emerging diseases, reported that as of 2024, 76 human cases of H5N1 infection had been documented, including 61 in the United States, predominantly among farm workers. While H5N1 remains primarily a poultry virus without evidence of human-to-human transmission, Dr. Van Kerkhove cautioned that the virus could adapt rapidly.

In addition to human infections, the United States has reported widespread H5N1 outbreaks in wildlife and poultry, as well as recent infections in dairy cattle across 15 states. Madhur Dhingra, Senior Animal Health Officer at FAO, emphasized the significant economic impact on global poultry industries, threatening food and nutrition security in affected regions. Beyond poultry, the virus has infected over 500 bird species and 70 mammalian species, including endangered animals such as California condors and polar bears, underscoring the broader ecological consequences.

Although human infections remain rare and the public health risk low, experts warn that ongoing animal-to-animal transmission continues to pose a threat. In response, WHO, FAO, and WOAH are calling for continued vigilance and collaboration to monitor and mitigate the virus's impact.