CDC Reports Rare Mutations in First Severe U.S. Bird Flu Case

 

The U.S. Centers for Disease Control and Prevention (CDC) announced Thursday that its analysis of samples from the first severe human case of bird flu in the country has revealed rare genetic mutations. These mutations were not present in samples collected from an infected backyard poultry flock on the patient’s property.

The mutations, found in the hemagglutinin (HA) gene, affect the virus's ability to attach to host cells. Despite these findings, the CDC reassured the public that the overall risk of the bird flu outbreak remains low.

The severe case was reported last week in a Louisiana resident over the age of 65, who experienced significant respiratory distress. The patient was infected with the D1.1 genotype of the virus, a strain previously identified in wild birds and poultry in the United States.

This strain differs from the B3.13 genotype, which has been linked to infections in dairy cows, humans, and some poultry across multiple states.

The mutations detected in the Louisiana patient are considered unusual, though they have been observed in other severe bird flu cases internationally. Similar mutations were noted in a recent severe case in British Columbia, Canada.

Such genetic changes are often associated with severe infections, but the CDC emphasized that no evidence of person-to-person transmission has been found in the Louisiana case.

The CDC is closely monitoring the outbreak and analyzing genetic data to assess any potential changes in the virus's behavior or transmissibility. Health officials continue to urge caution but have stressed that the current risk to the general population remains minimal.

Bird flu has primarily affected poultry and wild bird populations in the U.S., with sporadic human cases typically linked to close contact with infected animals. Public health agencies are working to contain the virus and prevent further spread, particularly to vulnerable populations.