Bird flu found in raw milk but federal agencies say the U.S. supply is safe

Bird flu virus has been detected in raw milk, federal agencies reported this week, but added that the nation's commercial milk supply remains safe.

The U.S. Department of Agriculture, the U.S. Food and Drug Administration and U.S. Centers for Disease Control and Prevention in a joint statement assured consumers that milk from cows infected with highly pathogenic avian influenza is destroyed or diverted, and that the pasteurization process, used for the vast majority of milk, “kills harmful bacteria and viruses.”

The FDA also noted that while pasteurization "is likely to inactivate the virus ... the process is not expected to remove the presence of viral particles."

"Therefore, some of the samples collected have indicated the presence" of the virus, it said, but additional testing to determine if the virus was viable showed "nothing that would change our assessment that the commercial milk supply is safe."

"Pasteurization is generally expected to eliminate pathogens to a level that does not pose a risk to consumer health," the FDA said, reiterating longstanding recommendations that consumers avoid drinking raw milk.

On Wednesday, the USDA issued an order to prevent the spread of the virus by requiring that dairy cows test negative for bird flu before they can be moved to other states. The agency also required veterinarians, laboratories and producers to report any positive test results.

More: Two vets hundreds of miles apart, both ISU grads, solve dairy cow sickness whodunit

The USDA’s directive came after dairy cows in Texas and Kansas became sick with highly pathogenic avian influenza in March, marking the first time the virus had moved from poultry to cattle.

Since 2022, state and federal officials have worked with producers to destroy 90.7 million chickens, turkeys and other birds nationally to contain the disease. Though the disease is deadly to birds, infected dairy cows mostly experience reduced appetite and milk production before recovering.

The virus has been discovered in 33 dairy operations in six states in addition to Kansas and Texas, the USDA said: Idaho, Michigan, New Mexico, North Carolina, Ohio and South Dakota. Iowa has no known cases ow of avian influenza in dairy cows or birds, the Iowa Department of Agriculture said Wednesday.

Over the past two years, about 18.8 million birds have been destroyed in Iowa, the nation’s top egg producer and seventh-largest turkey producer, USDA data shows. The last bird flu detection in the state was Dec. 20, and so far no cases have been reported among cattle.

Here's what you should know about the highly pathogen avian influenza outbreak.

How is the disease spreading?

Wild birds can spread highly pathogenic avian influenza to domestic birds and other animals through their droppings and saliva. The virus has been detected in more than a dozen wild mammals, including brown, black and polar bears, bobcats, grey seals and bottlenose dolphins. In Iowa, the virus has been detected in red foxes and Virginia opossums.

More: The bird flu has jumped to foxes, bears and other mammals. Are humans next?

How is the avian influenza virus spreading in cows?

The USDA says the virus has spread between cows in the same herd; from cows to poultry; and between dairies associated with cattle movements. It also says cows without symptoms have tested positive.

What about Iowa's large livestock population?

Iowa Agriculture Secretary Mike Naig urged the state's dairy and poultry producers to bolster their biosecurity to prevent the virus from entering their operations. Poultry producers have been on high alert since an initial wave of bird flu in 2015, when they were forced to destroy 32.7 million birds.

Scott Hayes, the former National Pork Producer Council president, told reporters this month that avian influenza is on producers’ radar. But the Missouri farmer said the industry already has adopted strict biosecurity measures to guard against deadly diseases like African swine fever. That's an important issue in Iowa, the nation's largest pork producer.

Iowa allows raw milk sales. Is it dangerous?

Iowa for Fresh Milk couldn’t immediately be reached for comment Wednesday. National group A Campaign for Real Milk said the federal agencies provided "no supporting evidence of viral transmission from raw milk to humans in the peer-reviewed literature.”

The FDA said it continues to recommend the dairy industry not manufacture or sell raw milk or raw milk products, given limited information about the possible transmission via raw milk.

Is bird flu from dairy cows a threat to people?

One person in contact with an infected herd in Texas became mildly ill, the CDC said. The USDA reported being on alert, though. Last week, a microbiologist detected “a shift” in a virus sample from a Kansas cow that could have indicated it had “an adaptation to mammals.” Further CDC analysis, however, showed it had been “seen previously in other mammalian infections and does not impact viral transmission."

Donnelle Eller covers agriculture and the environment for the Des Moines Register. Reach her at deller@registermedia.com.

This article originally appeared on Des Moines Register: Federal agencies find bird flu virus in raw milk but say supply is safe