New mutations identified in the avian flu virus

Genetic analysis sheds light on when the outbreak started, how the virus spread and where it could go.

The bird flu virus plaguing dairy farms in several states has acquired dozens of new mutations, some of which could make it better able to spread between species and less susceptible to antiviral drugs, according to a new study.

None of the mutations are alarming in themselves. But they highlight the possibility that as the outbreak continues, the virus could evolve in a way that allows it to spread easily between people, experts said.

"The flu mutates all the time -- that's kind of what the flu does," said Richard Webby, a flu expert at St. Jude Children's Research Hospital, who did not participated in the work.

“The real key would be that we start to see some of these mutations become more widespread,” Dr. Webby said. "This would increase the level of risk."

The virus, called H5N1, has infected cows in at least 36 herds in nine states, raising fears that milk could be infectious. concerns are now largely allayed – and highlight the risk that many viruses could be transmitted from one species to another in crowded farms.

The study was posted online Wednesday and has not been peer-reviewed. . He is one of the first to provide details of an Agriculture Department investigation that has remained mostly opaque until now, frustrating experts outside the government.

We are having trouble retrieving the article content. .

Please enable JavaScript in your browser settings.

Thank you for your patience while we verify access. If you are in Reader mode, please exit and sign in to your Times account, or subscribe to the entire Times.

Thank you for your patience while we let's check access.

Already subscribed?