An avian influenza outbreak among dairy cows in the United States has expanded to impact over twenty-five herds across eight states. This comes shortly after the detection of the virus in chickens belonging to the country's largest egg producer.
Health authorities emphasize that the likelihood of public exposure remains minimal, and assure that the safety and stability of the U.S. food supply are unaffected.
"The U.S. Food and Drug Administration stated that currently, there is no cause for concern regarding potential risks to consumer health or impacts on the safety of the interstate commercial milk supply," according to a statement.
Here's the essential information regarding bird flu and its impact on food:
Which states have reported cases of bird flu in dairy cows?
As of Friday, the avian flu strain responsible for the deaths of millions of wild birds in recent years has been detected in a minimum of 26 dairy herds across eight states in the U.S.: Idaho, Kansas, Michigan, New Mexico, North Carolina, Ohio, Texas, and South Dakota.
Federal health and animal agencies report that the virus, identified as Type A H5N1, has been identified in various mammals in recent years. However, this marks the first instance of its detection in cattle. The U.S. Centers for Disease Control and Prevention stated that genetic analysis of the virus does not indicate any modifications enabling easier transmission among humans.
How is bird flu impacting food production?
Agricultural authorities in a minimum of 17 states have imposed limitations on the importation of dairy cattle from states where the virus has been identified. However, according to government agencies, its influence on commercial milk production has been minimal thus far. Officials speculate that cows may have contracted the virus through contact with wild birds, though they acknowledge the possibility of transmission between cows.
Farmers are conducting tests on cows exhibiting symptoms of infection, such as significant decreases in milk production and lethargy. Those animals displaying signs of illness or testing positive are being isolated from other livestock on the farms. Fortunately, the affected animals seem to recover within a span of two weeks.
U.S. egg producers are closely monitoring the situation following the detection of bird flu in chickens in Texas and Michigan. While millions of birds have been euthanized, the FDA has stated that the likelihood of affected eggs entering the retail market or causing human infections is minimal due to rigorous federal inspections and additional safety measures in place.
Pasteurization, a heat treatment process used to kill harmful bacteria and pathogens in food and beverages, including milk and eggs, is effective in eliminating the bird flu virus. Scientists confirm that there is no evidence to suggest that individuals can contract the virus through consuming pasteurized or properly cooked food.
Lee-Ann Jaykus, an emeritus food microbiologist and virologist at North Carolina State University, emphasized, "It's not a food safety concern."
To date, two individuals in the U.S. have been infected with bird flu. One case involved a Texas dairy worker who developed a mild eye infection after close contact with an infected cow. The individual has since recovered. In 2022, another case occurred when a prison inmate participating in a work program contracted the virus while euthanizing infected birds at a poultry farm in Colorado. The only symptom reported was fatigue, and the individual also recovered.
Yes, according to food safety experts and government officials, grocery store milk is safe from bird flu.
U.S. producers are prohibited from selling milk from sick cows and are mandated to divert and dispose of it. Furthermore, milk distributed across state borders must undergo pasteurization, a heat treatment process designed to eliminate bacteria and viruses, including influenza.
"We firmly believe that pasteurization provides a safe milk supply," stated Tracey Forfa, director of the FDA's Center for Veterinary Medicine, during a webinar this week.
The FDA and the CDC are less certain about the safety of unpasteurized, or raw, milk in relation to bird flu. They note that there is limited information available regarding the potential transmission of the H5N1 virus through such products.
Thus far, no herds associated with raw milk providers have reported cases of bird flu-infected cows. However, the agencies recommend that the industry refrain from producing or selling raw milk or raw milk cheese products made with milk from cows exhibiting symptoms of illness or those exposed to infected cows.
U.S. health officials have consistently cautioned about the potential for foodborne illness associated with raw milk consumption. According to the CDC, raw milk was linked to over 200 outbreaks, resulting in the sickness of more than 2,600 individuals between 1998 and 2018.
Despite federal warnings, proponents of raw milk such as Mark McAfee, owner of Raw Farm USA in Fresno, Calif., have noted an increase in sales of raw milk products following the outbreak of H5N1 in commercial cows.
To date, only dairy cows, not beef cattle, have been infected or exhibited signs of illness due to bird flu, according to agriculture officials. As such, there is no evidence suggesting that individuals can contract bird flu from eggs or meat.
The largest egg producer in the U.S. temporarily ceased operations on April 2nd after detecting bird flu in its chickens. Cal-Maine Foods euthanized approximately 1.6 million laying hens and an additional 337,000 pullets (young hens) following the discovery.
The company stated that there was no risk to eggs already in the market, and no recall of eggs had been initiated.
"Eggs that are handled properly and cooked thoroughly are safe to eat," emphasized Barbara Kowalcyk, director of the Center for Food Safety and Nutrition Security at George Washington University.
"A lot of people enjoy runny eggs. Personally, if I eat an egg, it's very well cooked," she stated.
However, Kowalcyk and others cautioned that the situation could evolve.
"This is an emerging issue, and it's evident that this pathogen is evolving, leaving much that we don't yet understand," she said. "I believe that everyone is endeavoring to unravel this as swiftly as possible."