JP While the viruses’ risk to humans remains low, the researchers noted only a few amino acid changes are needed for that to change.
The ongoing outbreak of avian influenza, which began in late 2021 in Europe and the Americas, has been marked by rapid genetic changes and highly increased virulence in both birds and mammals, according to a new study published last week.
In the peer-reviewed study published in Nature Communications, researchers from the St. Jude Children’s Research Hospital in Memphis, Tennessee, found that the new strains of the H5N1 avian influenza virus changed rapidly and became more severe as they spread through Europe and the Americas in the past two years.
In recent months, increasing numbers of mammals have been found to be infected with the virus, with mass die-offs of seals and sea lions reported in Russia and the Americas and dozens of foxes, skunks, dolphins, raccoons, cats and other mammals found to be infected as well.
“We haven’t seen a virus quite like this one,” said corresponding author Richard Webby of St. Jude’s Department of Infectious Diseases in a press release. “In 24 years of tracing this particular H5N1 flu lineage, we haven’t seen this ability to cause disease but also be maintained in these wild bird populations.”
The scientists found that the virus gained a different version of a viral protein called neuraminidase, which increased its ability to transmit between birds, before arriving in Canada and then spreading to the rest of the Americas.