In early December, Sonoma County, California, declared an agricultural disaster when two poultry farms had to euthanize their entire flocks in an attempt to prevent the spread of “highly pathogenic avian influenza” – or bird flu. This particular strain of bird flu, H5N1, was first reported in the United States in early 2022, when horror stories about birds began to make headlines: two zoos reported bird flu among their flocks, prompting zoos in all parts of the country to remove their birds. -an offer; Three bald eagles in Georgia were injured and died; Hundreds of infected birds were found dead in a lake on the outskirts of Chicago.
Since then, tens of millions of turkeys and chickens have been killed on commercial farms in an attempt to stamp out the outbreak.
During a period of already persistent inflation, as cases of bird flu increased, so did the price of eggs. As reported by the University of Arkansas Department of Agriculture, avian flu has been blamed for rising egg prices in 2023, which peaked at $4.82 per dozen in January (the month last time, prices were around $2.99 per 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 prompted some experts to express concern about the fact that “the virus is more widespread among dairy products”. businesses. We thought about it before,” according to Reuters.
But how concerned are home cooks about the impact of bird flu on egg and dairy safety? 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 "avian plague", when 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 emphasizes that avian flu viruses do not generally infect humans. However, in its 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 bird flu. “The patient reported redness of the eyes – consistent with conjunctivitis – as the only symptom, and is recovering,” according to a CDC statement.
“The patient was asked to self-isolate and treated with an antiviral medication to treat the flu,” they wrote. “This infection does not change the health risk assessment of H5N1 avian influenza for the general American public, which the Centers for Disease Control and Prevention considers low.”
This is the second person infected in the United States, given the current wave of the disease. The first was a 2022 case in Colorado involving a person who had direct exposure to poultry and participated in the slaughter (evacuation) of poultry infected 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 livestock, with approximately 34 flocks affected as of Friday. Cows can become infected in several ways, including 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?
The Food and Drug Administration said Tuesday that samples of pasteurized milk tested positive for avian flu residue. They stressed at the time that the materials were inactive and "do not represent a real virus that could pose a danger to consumers."
According to Dr. Scott Roberts, infectious disease specialist at the hospital Yale New Haven and assistant professor of infectious diseases at Yale University School of Medicine, there is little risk of transmission through supermarket eggs and milk because a person must have direct contact with the infected animal.
“But even more so, the pasteurization process will kill any viable virus,” Roberts said.
The FDA issued a statement to deliver a similar message Friday after the agency received additional results from "a limited initial set of geographically targeted samples as part of the ongoing nationwide study of commercial milk samples coordinated by the USDA.
"The FDA continues to analyze this information; however, preliminary results from egg inoculation testing on qPCR-positive retail milk samples show that pasteurization is effective in inactivating avian influenza. These additional tests do 'have detected no live infectious virus.' These results support our assessment that the commercial milk supply is safe.
As a result, experts recommend avoiding raw or unpasteurized milk products as well as eggs.
What else?
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, director of the USDA 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 an FDA statement released Friday, the agency will continue to evaluate retail samples from its study of 297 retail dairy samples from 38 states.
“All samples with a positive PCR result are subjected to an egg inoculation test, which is the gold standard for determining whether an infectious virus is present,” they wrote. "These important efforts continue and we are committed to sharing additional test results as soon as possible. Subsequent results will help us further revise our assessment that pasteurization is effective against this virus and that the commercial milk supply is safe ."