After identifying remains of the bird flu virus in grocery store milk, federal officials announced Wednesday that they “believe” the nation’s milk supply is safe and that the virus is inactivated by pasteurization.
Don Prater, acting director of the U.S. Food and Drug Administration, said, “Pasteurization means heating milk to a specific temperature for a specific period of time to limit the activity of pathogens to levels that do not pose a threat to consumer health.” does not do.” Center for Food Security and Applied Nutrition,
However, Prater acknowledged that “there have been no studies on the effects of pasteurization on HPAI.”highly pathogenic avian influenza) Virus and Bovine Milk have already been completed.”
Wednesday’s safety assurance comes after a series of outbreaks of bird flu at dairy farms in eight states. FDA scientists said they have identified genetic material from existing bird flu strains in samples of pasteurized milk from grocery stores. DNA testing conducted so far was unable to conclusively determine whether the viral particles were active or inactive.
Prater described the situation as novel and evolving but stressed that pasteurization and sterilization “have served public health well for more than 100 years.”
Suresh Kuchipudi, professor and chair of the department of infectious diseases and microbiology at the University of Pittsburgh’s School of Public Health, said studies conducted on similar virus types indicate that pasteurization cannot eliminate the virus, but it can inactivate it. Will give.
Don O’Connell, assistant secretary of Health and Human Services for preparedness and response, stressed that the risk to human health remains low, but that the federal government is “vigilant and always ready” to keep the American people safe.
California’s state veterinarian, Annette Jones, said there has been no detection of the virus in California cattle, and a network of state and private veterinarians is in close contact with the dairy industry and individual farmers.
However, despite such assurances, some experts have questioned the timeliness of the government’s response to the outbreak.
Eric Topol, professor of molecular medicine at Scripps Research, said when he Glad the government is finally coming together “It definitely took a while” to get the information together on Wednesday.
He said the government has probably known about the positive samples for a few weeks, if not months. He 239 DNA sequences were released on Sunday night Which revealed the presence of the virus in commercial milk samples.
“They didn’t get these views overnight,” Topol said. “They’ve got them.”
Analysis of those sequences suggests a single origin of the virus in dairy cattle during some point in late 2023 or early 2024 – possibly from an infected bird, but possibly from infected food,
“I don’t know that we’re out of the woods by any means, because there’s so much spread among cattle in the country now that we just need a bad recombination event,” Topol said, referring to the possibility that it could be caused by humans. The genes of the flu virus have combined with the cattle virus to create a new or altered version that may be more problematic for people.
“It feels like it’s COVID all over again,” Topol said, recalling officials’ response in the weeks and months following the pandemic’s outbreak in early 2020.
At a Wednesday news conference, officials said researchers were actively testing viral particles found in milk samples in the laboratory to see if they could be grown in cell cultures or embryonated chicken eggs. . These tests will indicate whether the virus is active, said Gene Marrazzo, director of the National Institute of Allergy and Infectious Diseases.
Government officials and researchers said they were expanding their monitoring and surveillance and suggested that more information would be released in the coming days.
He also issued a federal order requiring laboratories to report any dairy cattle testing positive for avian flu or any type of influenza A, as well as testing all milking dairy cattle moving between states. Give report. In addition, any farms where bird flu-positive cows have been discovered must undergo epidemiological investigation and movement tracing, said Mike Watson, administrator of the Animal and Plant Health Inspection Service.
The number of milk samples tested, as well as details of where, how and why they were obtained, were not shared with journalists.
At least one outside expert said he doubted government researchers would find an active virus in the milk samples
Michael Payne, a researcher and outreach coordinator at the Western Institute for Food Safety and Security at UC Davis, said, “I would bet five mortgage payments” that they would not find live or active virus in the samples.
“As an Eagle Scout (Northeast Georgia Council, 1976) I say this to you with complete honesty and transparency: I would not hesitate to drink pasteurized milk from any dairy herd in the United States, nor to serve it to my family. I will hesitate.” State,” he said.
During the news conference, officials said they are also keeping a close eye on cases of human infection.
Nirav Shah, principal deputy director of the US Centers for Disease Control and Prevention, said the agency has tested 23 people for the virus and is actively monitoring 44 people “who are considered exposed and at risk for infection.” “
Only one human case has been identified so far in the current outbreak, and that person is reported to be exhibiting only mild symptoms.
However, in other places where humans have been infected, the virus has made people sick and even fatal. According to the World Health Organization, which is tracking the virus, between January 2003 and February 2024, there were 887 confirmed cases of human infection in 23 countries. Of these, 462 were fatal.
While the current virus has not evolved the ability to become more infectious to humans, researchers have seen some worrisome mutations.
These include observations of the virus spreading between cows in the same herd, spread from cows to chickens, and between dairies associated with cattle movement. It has also been found in cows that did not have clinical signs of the disease – indicating that it is going unnoticed.
Also, on April 16, a USDA microbiologist “identified a change” in a sample from McAllen, Kan., that shows a mutation that would make it more infectious among mammals, USDA official Watson said. He said further analysis from the CDC showed that “the overall risk remains low.”
