Colorado has been added to the states where dairy cattle have been found infected with highly-pathogenic avian influenza that has claimed millions of farmed chickens and turkeys in the United States and Canada.
And it may be far more widespread among cattle.
One in five commercial milk samples tested in a nationwide survey contained particles of the H5N1 virus, the U.S. Food and Drug Administration said late on Thursday. The agency said there is no reason to believe the virus found in milk poses a risk to human health.
“This says this virus has largely saturated dairy cattle throughout the country,” said Dr. Michael Osterholm, an infectious disease expert at the University of Minnesota.
Many infectious disease experts and government officials have said they believe the pasteurization process will inactivate the virus, also known as avian influenza. However, additional testing is needed to confirm that there is no infectious virus in the milk, the FDA said.
“I’m not worried about the milk itself,” said Samuel Alcaine, associate professor, of food science at Cornell University. “It does indicate that the virus is more widespread among dairies than we had previously thought.”
Osterholm said the developments suggest the U.S. should be doing much more sampling, in both dairy and beef cattle, as well as pigs, which are a frequent mixing vessel for flu viruses that can be transmitted to people.
So far there have been no reports of the virus in Canadian cattle, but Canadian officials have not said if milk samples are being tested.
