Bird flu is spreading. Are supermarket eggs and milk safe?

In early December, Sonoma County, California, declared an agricultural disaster when two poultry farms had to kill their entire flocks in an attempt to prevent the spread of “highly pathogenic avian influenza” – or bird flu. This particular strain of avian flu, H5N1, was first reported in the United States in early 2022, when more and more avian horror stories began making headlines: two zoos reported bird flu among their flocks, prompting zoos across the country to remove their birds. -display; three bald eagles were infected in Georgia and died; Hundreds of infected birds were found dead on the edge of a lake in the Chicago suburbs.

Tens of millions of turkeys and chickens on commercial farms have since been killed in an attempt to stamp out the outbreak.

At a time of already sustained inflation, as cases of bird flu increased, so did the cost of eggs. As reported by the University of Arkansas Division of Agriculture, avian flu has been blamed for rising egg prices in 2023, which peaked at $4.82 per dozen in January (the last month, they were hovering around $2.99 ​​a dozen, for reference).

Then, on Thursday evening, the Food and Drug Administration announced that one in five commercial milk samples tested in a national survey contained particles of the H5N1 virus, a finding that led some experts to express concern about the fact that “the virus is more widespread in dairies than in dairies”. we thought so before,” as Reuters reports.

But how concerned should home cooks be about the impact of bird flu on the safety of their eggs and dairy products? Let’s dive into what we know.

What is bird flu?

According to the Centers for Disease Control and Prevention (CDC), avian influenza, or bird flu, is a virus that spreads naturally among wild waterfowl around the world. The disease was first identified in Italy in the late 19th century and was initially called “bird plague” because it was confused with a form of avian cholera. The term “bird flu” gained popularity during the 20th and 21st centuries, following outbreaks of highly pathogenic strains such as H5N1 and H7N9 (and the first international avian flu symposium held in Paris, France, in 1981).

The CDC maintains that avian flu viruses do not normally infect humans. However, in a summary of the current situation, the organization states that “sporadic human infections with avian influenza viruses have occurred.” This is the case with the current strain, H5N1.

On April 1, a Texas dairy farm worker who had been exposed to livestock tested positive for H5N1 avian flu. According to a CDC statement, “the patient reported redness of the eyes – consistent with conjunctivitis – as the only symptom, and is recovering.”

“The patient has been asked to self-isolate and is being treated with an antiviral flu medication,” they write. “This infection does not change the human health risk assessment of H5N1 avian influenza for the general American public, which the CDC considers low.”

This is the second human in the United States to report being infected as part of the current wave of the disease; the first was a 2022 case in Colorado involving a “person with direct exposure to poultry and involvement in the slaughter (depopulation) of poultry with suspected H5N1 avian influenza.”

Although transmission of avian influenza to other mammals is rare, it is possible. Currently, nine states – North Carolina, Ohio, Michigan, Texas, New Mexico, Colorado, Kansas, South Dakota and Idaho – have reported avian flu outbreaks among cattle, with approximately 34 herds affected as of Friday. The cows could have become infected in several ways, including coming into direct contact with infected birds, living in a contaminated environment, or consuming feed containing contaminated poultry by-products or feces.

Are supermarket eggs and milk safe to eat?

On Tuesday, the Food and Drug Administration said samples of pasteurized milk tested positive for remnants of bird flu. At the time, they stressed that the materials were inactivated and “do not represent a real virus that could pose a risk to consumers.”

According to Dr. Scott Roberts, an infectious disease specialist at Yale New Haven Hospital and assistant professor of infectious diseases at the Yale School of Medicine, there is little risk of transmission in supermarket eggs and milk because it requires have direct contact with the infected animal.

“But even more so, the pasteurization process would kill any viable virus,” Roberts said.

On Friday, the FDA issued a statement communicating a similar message after receiving additional results from “an initial limited set of geographically targeted samples as part of its ongoing national commercial milk sampling study in coordination with the USDA.”

“The FDA continues to analyze this information; However, preliminary results from egg inoculation tests on quantitative polymerase chain reaction (qPCR)-positive retail milk samples show that pasteurization is effective in inactivating HPAI (bird flu),” they wrote. “These additional tests did not detect any live, infectious virus. These results reaffirm our assessment that the commercial milk supply is safe.

As a result, experts recommend avoiding unpasteurized or raw milk and egg products.

And after?

Until now, farmers only had to test their dairy cows for bird flu or if their herd showed symptoms of infection, but the USDA announced last week that every lactating cow must now be tested and show a result negative before moving to a new state. This will help authorities track the disease and understand how it spreads, according to Michael Watson, administrator of the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service.

“We think we can do tens of thousands of tests a day,” Watson told the Associated Press.

Next, according to Friday’s FDA release, the agency will continue to further evaluate retail samples from its study of 297 retail dairy samples from 38 states.

“All samples with a positive PCR result are subjected to egg inoculation testing, a gold standard for determining whether an infectious virus is present,” they wrote. “These important efforts continue and we are committed to sharing additional testing results as soon as possible. Further results will help us further revise our assessment that pasteurization is effective against this virus and that the commercial milk supply is safe.