Emergence of New Bird Flu Strain H5N9 Sparks Concern Among Experts

A novel strain of bird flu, specifically the highly pathogenic avian influenza (HPAI), has been identified at a duck farm in California. This detection has raised alarms within the scientific community and among health officials.

World Organization for Animal Health Reports New Outbreak

The World Organization for Animal Health (WOAH) officially announced the outbreak of H5N9 earlier this week through its public communications. Additionally, this farm, located in Merced County, was also found to be hosting the more commonly recognized H5N1 strain of the virus.

First Confirmation of HPAI H5N9 in U.S. Poultry

WOAH stated that this marks the first confirmed case of HPAI H5N9 in poultry across the United States. Consequently, health agencies are launching comprehensive epidemiological investigations and increasing surveillance efforts in response to this finding.

Expert Insights on the Adaptability of Influenza Viruses

David J. Cennimo, an associate professor of medicine and pediatrics specializing in infectious diseases at Rutgers New Jersey Medical School, highlighted the adaptability of influenza viruses in his commentary. He pointed out that birds are particularly susceptible to various strains of avian influenza, which can range from mild to lethal.

Cennimo mentioned that while H5N9 has been observed previously, it typically results in mild illness among birds. Unfortunately, the ducks on this California farm were reported to be dying, with genetic tests confirming that this specific strain of H5N9 is different from historical samples, representing a reassortment of virus segments.

Understanding Virus Reassortment

The process of reassortment occurs when influenza viruses exchange genetic material, as noted by the National Institutes of Health. Cennimo explained that influenza strains are categorized based on their hemagglutinin and neuraminidase surface proteins, denoted by Hs and Ns.