Bird Flu Virus in Canadian Teen Shows Mutations That Could Help It Spread Among Humans

FRIDAY, Nov. 22, 2024 (HealthDay News) — In a development that health experts have warned might come, Canadian officials report that the bird flu virus isolated from a sick teen in Vancouver shows mutations that could help it spread more easily among humans.

At this point, there is no evidence that this particular mutated H5N1 virus has traveled beyond the one Canadian patient: After monitoring of dozens of potential contacts among the teen’s friends, family and health care providers, “no further cases have been identified,” Dr. Bonnie Henry, provincial health officer for the province of British Columbia, told CNN.

Still, scientists say the genetic changes seen in the Canadian case are ominous.

“Certainly, this is one of the first times that we’ve really seen evidence of these sort of adaptation mutations in H5,” Dr. Jesse Bloom, a computational virologist at the Fred Hutchinson Cancer Center in Seattle, told CNN.

Bloom noted that the teen started experiencing symptoms a week before being admitted to the hospital, and that may have given the virus time to become better at entering the cells it was trying to infect.

Importantly, the virus that infected the teen, who remains in critical but stable condition, is not the same strain as the one striking dairy cattle in the United States. Instead, it more closely resembles an H5N1 strain that is circulating in wild bird flocks in the Pacific Northwest, CNN reported.

Canadian officials say they still don’t know how the teen was infected, since there was no known contact with wild birds.

The three mutations seen in the Canadian case sit at spots on the genome that scientists have deduced would allow it to attach more easily to human cells, CNN reported.

“It’s caught the attention of a lot of flu virologists, including myself, because some of the sequence has evidence of some of the types of mutations we worry about,” Bloom said.

Meanwhile, a child in California tested positive for bird flu earlier this week, despite having no known contact with infected animals.

“California has identified a possible bird flu case in a child in Alameda County who was tested for mild upper respiratory symptoms. The child, who has been treated, is recovering at home,” the California Department of Public Health (CDPH) said in a news release.

While the patient had no known contact with an infected animal, health officials are investigating a possible exposure to wild birds, the CDPH added.