FDA finds traces of H5N1 avian influenza virus in milk at grocery store, but says pasteurized dairy products are still safe

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The U.S. Food and Drug Administration announced Tuesday that H5N1 avian influenza virus particles have been detected in milk purchased at grocery stores, but the agency said it still believes the milk is safe to drink.

in update Regarding the continuing outbreak of avian influenza in cattle, the FDA notes that the virus particles, detected by sensitive laboratory tests, are likely to be remnants of virus killed during the pasteurization process. did. The agency said it believes the particles are unlikely to infect humans, but is conducting additional testing to be sure.

The FDA said these egg inoculation tests are the “gold standard” for determining whether the virus is still viable and can be transmitted to humans.

“To date, we have not seen anything that would change our assessment that the commercial milk supply is safe. Results from multiple studies will be published in the coming days and weeks.” said the authorities.

Dr. Eric Topol, founder of the Scripps Research Translational Institute, said the finding of virus particles in milk on grocery store shelves means the outbreak is probably more widespread than we know. He said that it means that

“Infection in cattle is much larger than we believe,” Topol said in an email Tuesday.

“The FDA’s assurance that the dairy supply is safe is great, but it is not yet based on extensive evaluation, which FDA acknowledges, and it is subject to USDA mishandling, so it cannot be trusted.” “It does not create confidence or confidence,” he added.

In late March, the U.S. Department of Agriculture confirmed the detection of highly pathogenic avian influenza in dairy cows in Texas and Kansas, indicating that the virus that is decimating bird populations around the world has emerged from cattle. It was the first time I had ever done that. Since then, infected cattle have been confirmed on more than 30 farms in eight states. Scientists and the Department of Agriculture say: Too little information to share About the virus, and it's too late.

Infected cows didn't eat as much as they normally would, and their milk became thicker and discolored. Veterinarians who tested the animals found that although samples taken from the lungs did not show much evidence of infection, the milk was rich in the virus, and doctors said it was likely due to shared milking. They suspected that the animal's mammary glands may have been infected directly through the equipment. .

Researchers are still working to understand how cows were first infected and how the virus spread between animals.

A cat that lived on the same farm as the infected cow died, probably due to exposure to the milk.

The FDA said Tuesday that milk from sick cows is “diverted or discarded,” while milk sold in interstate commerce is pasteurized, which involves heating it briefly to kill microorganisms. Announced.

“Even if viruses are detected in raw milk, pasteurization is generally expected to remove the pathogen to a level that does not pose a risk to consumer health,” the FDA said.

The agency said 99% of commercially supplied milk comes from farms that comply with the Pasteurized Milk Ordinance, which “includes controls to ensure the safety of dairy products.” However, we also note that pasteurization does not make milk completely sterile.

To that end, the company is testing milk samples collected at grocery stores across the country. We also work with the Centers for Disease Control and Prevention's Food Safety Group.

The FDA has long advised consumers not to drink unpasteurized or raw milk. bacteria May pose serious health risks.

So far, current efforts to track the spread of owlbreak rely on voluntary reporting.

USDA Animal and Plant Health Inspection Service holds a list List of mandatory reportable diseases in animals. Reporting of avian influenza is mandatory for poultry and wild birds, but not for cattle.

“No one thought it could also infect cows,” said Dr. Richard Webby, director of the Influenza Ecology Research and Coordination Center at the World Health Organization's St. Jude Children's Research Hospital.

“You would never think that H5N1 in cattle is something you need to worry about. I think this is where H5N1 is starting to trickle out.”

USDA not only requires reporting of H5N1 infections in poultry, but also rewards producers who report the first sign of disease in their flocks. compensate them financially For birds and eggs destroyed to stop outbreaks. Dr. Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, said this approach has encouraged farmers to come forward with information.

There are no policies in place to encourage reporting in other livestock.

Mr Osterholm said a big concern was that the outbreak could spread to pigs, as farms that raise cattle often also raise other types of animals.

Influenza viruses invade cells through the following routes: sialic acid, serves as an entry point. To date, the H5N1 virus has not learned how to efficiently access the human version of the sialic acid receptor.

For pigs, Same sialic acid receptor Birds and humans are similar in their respiratory tracts. Osterholm said if H5N1 were to cause an outbreak in pigs, there would be a perfect opportunity to learn that the virus attaches to human sialic acid.

“Pigs are a more efficient mixing bowl,” says Dr. Peter Hotez, professor of pediatrics, molecular virology, and microbiology at Baylor College of Medicine in Houston. “One thing about our state of Texas is that in addition to cattle, Texas is also home to feral hogs.”

“In the United States, we have 2 million to 3 million feral pigs, 30% of the country's feral pigs, and that's a potential risk to me, too,” he said.

The USDA said it encourages farmers and ranchers to report cases of sick cattle to state animal health officials.

However, neither cows nor the people who work or live around them are widely tested for infection, which requires informed consent. Wastewater testing in the affected areas is also being discussed.

Instead, the CDC is monitoring emergency department data and influenza testing data in areas where the H5N1 virus has been detected in dairy cows, looking for unusual trends in influenza-like illness, influenza, and conjunctivitis. “So far, these data are within expectations and our surveillance systems have not shown any unusual trends or activity to date,” according to a statement compiled by CDC officials.

CDC spokesman Jason McDonald said 23 people infected with H5N1 have been tested, including one person in Texas who previously tested positive. No other people have tested positive during the current outbreak.