The Centers for Disease Control and Prevention (CDC) has discovered genetic mutations in a strain of the H5N1 avian influenza virus, commonly known as bird flu, in a patient from Louisiana. Notably, these mutations were absent in poultry samples from the patient’s property, suggesting they developed after infection.
The patient, who was exposed to sick and dead birds in backyard flocks, was hospitalized, according to a CDC press release issued on December 13. Previous U.S. cases of H5N1 have been mild, primarily affecting farmworkers in direct contact with infected poultry or dairy cows.
CDC analysis of the Louisiana case identified changes in the hemagglutinin (HA) gene, a crucial element for the virus’s ability to infect host cells. Similar mutations have been documented in rare severe cases worldwide, including one recently reported in British Columbia, Canada.
Despite these findings, the CDC emphasized that the overall risk to the public remains low. “The detection of a severe human case with genetic changes in a clinical specimen underscores the importance of ongoing genomic surveillance in people and animals, containment of avian influenza outbreaks, and prevention measures for those exposed to infected animals or environments,” the agency stated in its December 26 update.
No evidence of transmission from the Louisiana patient to others has been detected, the CDC confirmed, reiterating that the risk to the general population remains unchanged.
