Bird Flu in Human Patient Shows Worrisome Mutations

Centers for Disease Control and Prevention scientists say they found "concerning" mutations in the bird flu virus in the first confirmed US case involving severe illness—but the mutations appear to be confined to the patient. In a news release, the CDC said the mutations in the H5N1 virus were not found in samples from poultry on the Louisiana patient's property, "suggesting the changes emerged in the patient after infection."

• The mutations. The CDC said the mutations made it easier for the virus to bind to cell receptors in people's upper airways, STAT News reports. A similar mutation was found in a teenager in British Columbia who became severely ill with bird flu last month.

• No transmission to other persons identified. "Although concerning, and a reminder that A(H5N1) viruses can develop changes during the clinical course of a human infection, these changes would be more concerning if found in animal hosts or in early stages of infection (e.g., within a few days of symptom onset) when these changes might be more likely to facilitate spread to close contacts," the CDC said. "Notably, in this case, no transmission from the patient in Louisiana to other persons has been identified."
• "Not great news." "It's not great. It's not great news," Scott Hensley, a professor of microbiology at the University of Pennsylvania's Perelman School of Medicine, tells STAT. Hensley says the CDC report is enough to raise his eyebrows, but he believes people shouldn't read too much into data from the two severe cases. At least 65 milder cases of bird flu in humans have been reported in the US since March.
• "Like a pull of a slot machine lever." Because the virus mutates in people and animals, "each infection is like a pull of a slot machine lever," KFF Health News reports. Experts say the failure to stop the spread of the virus among dairy herds has caused them to lose faith in the federal government's ability to control the outbreak. "We are in a terrible situation and going into a worse situation," says Angela Rasmussen, a virologist at the University of Saskatchewan. "I don't know if the bird flu will become a pandemic, but if it does, we are screwed."

(The virus killed 20 big cats at a sanctuary in Washington state.)