
The first severe case of bird flu in the U.S. is showing signs of mutation, stoking fears that the virus could become more transmissible among humans, the U.S. Centers for Disease Control and Prevention has announced.
The sample taken from the patient in Louisiana showed mutations in the gene responsible with attaching to a host’s cells, the CDC said Thursday.
The CDC has confirmed a total of 66 human cases of bird flu across the United States as of Friday, although the number is believed to be higher. While the human cases have been mostly mild, the H5N1 bird flu outbreak has wreaked havoc in the American egg industry and heightened concerns about a new pandemic.
Although the CDC said the Louisiana case is “concerning,” the agency reiterated that no person-to-person spread of bird flu has been detected so far.
Here is what we know.
“It has been determined that the patient had exposure to sick and dead birds in backyard flocks,” the CDC said.
A mutation has also been reported in British Columbia, Canada.
This week, Northwest Naturals recalled a line of its raw and frozen chow after health authorities linked the death of a cat to a batch of feed contaminated with bird flu.
The recalled products include the company’s 2-pound bags of its Feline Turkey Recipe that have a best-by date between May 21, 2026, and June 23, 2026.