Feds: No plans to expand mandatory bird flu tests for all dairies

There are no imminent plans to broaden the mandatory testing of raw milk for avian flu at dairies beyond Colorado, where the testing recently identified 10 new infected herds, according to federal officials.

"It's probably unique to Colorado, and extrapolating that out to the rest of the country is not entirely appropriate," said Eric Deeble, a veterinarian who is deputy undersecretary for marketing and regulatory programs for the U.S. Department of Agriculture, in a call with reporters Tuesday.

He said the concentration of dairies in one county of that state — and the relatively frequent travel of workers among them — accelerated the spread of highly pathogenic avian influenza there.

Colorado's more than 60 infected dairy herds account for nearly a third of the known infected herds nationwide, though the virus has been found in cattle in 13 states. Iowa has not had a confirmed new infection since late June. The virus has been detected in 13 dairies in Northwest Iowa.

Wild birds are believed to be the initial source of cattle infection in December 2023 in Texas, but the virus wasn't identified until March. From Texas, it spread to other states with the transportation of infected cattle. There is now mandatory testing of lactating cattle before they can be moved over state lines.

The virus is believed to have circulated locally within those other states when people and their equipment moved between dairy farms.

The Iowa Department of Agriculture and Land Stewardship requires dairy cattle that are transported for exhibition — such as at the Iowa State Fair — to be tested for avian flu. Further, testing is also required at dairies that are near infected poultry sites.

Don McDowell, a spokesperson for the department, declined to say what other mandatory testing has been considered for Iowa, but that “we are continually evaluating our response to this evolving situation."

The virus is highly transmissible and often fatal for domestic chickens and turkeys, and entire flocks are culled to limit the virus' spread. Cows typically recover, but it can be a month or more before an infected herd's milk production resumes to normal rates.

The virus has also infected 13 people this year across the country — but none in Iowa — who had close contact with infected cattle and poultry, according to U.S. Centers for Disease Control and Prevention data. All had minor respiratory or pinkeye symptoms and recovered.

Five of those people were tasked with killing chickens at an infected flock in Colorado in July. About a week later, the state mandated the testing of raw milk at all of its licensed dairies.

The commercial milk supply remains safe for human consumption, the U.S. Food and Drug Administration said Tuesday. Its recent six-week sampling of pasteurized milk, cheese and other dairy products found no live bird flu viruses.

But about 17 percent of the samples contained non-infectious genetic material from the virus, which indicates tainted raw milk had entered the supply chain and was inactivated by pasteurization. None of that sampling happened in Iowa.

"(Testing) everything is a lot, and so we’re working with our state co-regulators to understand where in the processing chain does it make the most sense to begin the testing and to continue testing," said Dr. Steve Grube, a chief medical officer for the FDA. "This is not a sprint. This is a marathon. We need to understand, as a nation, how we can address this outbreak and bring it to a swift-as-possible end."