The virus is poised to become a permanent presence in cattle, raising the odds of an eventual outbreak among people.
Without a sharp pivot in state and federal policies, the bird flu virus that has bedeviled American farms is likely to find a firm foothold among dairy cattle, scientists are warning.
And that means bird flu may soon pose a permanent threat to other animals and to people.
So far, this virus, H5N1, does not easily infect humans, and the risk to the public remains low. But the longer the virus circulates in cattle, the more chances it gains to acquire the mutations necessary to set off an influenza pandemic.
“I think the window is closing on our ability to contain the outbreak,” said Dr. Krutika Kuppalli, an infectious-disease physician who worked at the World Health Organization until April.
“We’re so quick to blame China for what happened with SARS-CoV-2, but we’re not doing any better right now,” she added. “That’s how pandemics happen.”
Half a year into the outbreak, H5N1 shows no signs of receding in U.S. dairy cattle or in the workers who tend them. In recent weeks, the virus has spread into poultry and workers.
As of Wednesday, infections had been reported in 192 herds of cattle in 13 states, and in 13 people. Nine were workers at poultry farms close to dairy farms in Colorado.