The U.S. Department of Agriculture (USDA) has initiated a nationwide testing program for raw milk following the ongoing spread of the H5N1 avian influenza virus, commonly known as bird flu, among the nation’s cattle population. This mandatory testing, implemented through a federal order, requires dairy farms to provide raw milk samples upon request. This proactive measure aims to enhance surveillance of the virus’s trajectory since its initial detection in U.S. cows in March and to safeguard agricultural workers who handle potentially infected animals. While previous FDA testing of pasteurized milk revealed only harmless, non-infectious traces of the virus, raw milk, which bypasses the pasteurization process, poses a greater risk of harboring the live virus. This heightened concern stems from the discovery and subsequent recall of two contaminated batches of raw milk products in California, the state most affected by the cattle outbreak. Although the 58 human cases identified thus far in the U.S. have primarily been linked to direct contact with poultry and cattle, and not raw milk, the potential for transmission through contaminated raw milk cannot be ignored.
Raw milk, unlike its pasteurized counterpart, has not undergone the heat treatment process that eliminates most harmful bacteria and viruses. While some consumers prefer raw milk for its perceived taste and nutritional superiority, scientific evidence supporting these claims is lacking. Experts, including John Lucey, Director of the University of Wisconsin’s Center for Dairy Research, consider these claims unfounded and misleading. Conversely, the risks associated with consuming raw milk are well-documented. Unpasteurized milk can harbor a variety of dangerous pathogens, including bacteria like Salmonella, E. coli, and Listeria monocytogenes, as well as viruses responsible for diseases like tuberculosis, diphtheria, and scarlet fever. The Centers for Disease Control and Prevention (CDC) reported 75 raw milk-related foodborne illness outbreaks between 2013 and 2019, impacting 675 individuals, with half of the cases involving children and teenagers.
Pasteurization, the process of heating milk to eliminate harmful microorganisms, is a standard practice applied to a range of food and beverage products, including juice, wine, and beer. The U.S. dairy industry commonly utilizes a high-temperature, short-time (HTST) method, heating milk to at least 161°F (71°C) for 15 seconds, which is highly effective against the bird flu virus. This process, named after Louis Pasteur, who developed a similar method for wine in 1864, has revolutionized food safety. Prior to World War II, milk was implicated in approximately 25% of foodborne illnesses in the U.S., a risk drastically reduced by the widespread adoption of pasteurization. This intervention is recognized as one of the most impactful food safety measures in history.
The potential health consequences of consuming raw milk contaminated with bird flu remain an area of ongoing investigation. However, experts caution against the consumption of raw milk due to its inherent risks. Historically, unpasteurized milk has been linked to numerous illnesses, including bovine tuberculosis and typhoid fever. The FDA explicitly advises against drinking raw milk due to the potential for bird flu contamination and its illegality for interstate sale, a stance supported by food safety experts like Kerry E. Kaylegian, Associate Research Professor of Food Science at Penn State. While research continues to unravel the transmission patterns of H5N1, the consensus among experts underscores the unnecessary risks associated with consuming raw milk, especially given the readily available and safer alternative of pasteurized milk.
The intensified focus on raw milk testing amid the bird flu outbreak reflects a proactive approach to safeguarding public health. The mandatory testing program will enhance surveillance efforts, allowing officials to closely monitor the spread of the virus and implement appropriate control measures. The testing initiative also aims to protect agricultural workers, who are on the front lines of animal care and potentially exposed to the virus. By expanding testing to include raw milk, authorities hope to gain a more comprehensive understanding of the virus’s presence in the food chain and mitigate the risk of human infection.
While human cases of bird flu linked to raw milk consumption have not been reported in the U.S., the recall of contaminated raw milk products in California highlights the potential for transmission through this route. Although the majority of human cases have been linked to direct contact with infected poultry and cattle, the possibility of raw milk contamination necessitates increased vigilance and precautionary measures. The ongoing monitoring and testing of raw milk will provide crucial data to inform risk assessments and public health recommendations. This comprehensive approach seeks to address potential transmission pathways and protect consumers from the potential health risks associated with raw milk consumption during the bird flu outbreak.
