Cornell Study Finds That H5N1 Virus Can Survive and Remain Infectious in Cheese and Milk for as Long as 4 Months!
Nikhil Prasad Fact checked by:Thailand Medical News Team Oct 16, 2025 3 hours, 36 minutes ago
Medical News: H5N1 virus survives for months in dairy products
Scientists from Cornell University have uncovered alarming findings about the highly pathogenic avian influenza H5N1 virus—revealing that it can survive and remain infectious in raw milk and certain types of cheese for up to four months. The research, led by Dr. Diego Diel and Dr. Nicole Martin, sheds light on the persistence of this dangerous virus in dairy environments and its potential public health implications. According to the Cornell team, even after 120 days of cheese aging at 39°F, infectious virus particles were still detectable. This
Medical News report highlights the concerning implications of this discovery for both consumers and the dairy industry.
Cornell Study Finds That H5N1 Virus Can Survive and Remain Infectious in Cheese and Milk for as Long as 4 Months!
Key research institutions behind the study
The study was conducted by experts from Cornell University’s College of Veterinary Medicine (CVM) and the College of Agriculture and Life Sciences. Dr. Diel, a professor of virology and director of the Virology Laboratory at the Animal Health Diagnostic Center, and Dr. Martin, director of the Milk Quality Improvement Program, led the project. Their research follows previous findings that infected dairy cattle shed high levels of H5N1 virus in milk, suggesting that contaminated dairy products could be a silent route of exposure for humans.
Virus stability in cheese linked to acidity levels
Researchers found that the virus’s survival strongly depended on the acidity of the cheese. While no infectious virus was detected in cheeses with a pH of 5 or lower—such as feta—those with higher pH levels (between 5.8 and 6.6), including cheddar and camembert, retained active virus even after months of storage. The team demonstrated that traditional raw milk cheese-making processes, even under FDA-required 60-day aging rules, may not always inactivate the virus if the cheese is less acidic. These results emphasize that the safety of raw milk products can vary widely depending on production conditions.
Animal experiments confirm infection risks
To evaluate real-world risks, researchers fed contaminated raw milk and cheese to ferrets, an established model for influenza transmission. Interestingly, ferrets that consumed infected raw milk became ill, while those given contaminated cheese did not show signs of infection. The team suspects that the liquid nature of milk allows the virus greater contact with mucosal tissues, while the solid form of cheese limits exposure time. However, they cautioned that this does not eliminate all risks, particularly for individuals who consume raw dairy frequently.
Implications for the dairy industry
The study suggests that additional safety measures are needed to protect consumers and prevent virus persistence in dairy products. Dr. Martin proposed that testing milk before cheese production and adopting low-heat treatment methods coul
d help reduce risk while maintaining the flavor characteristics valued by raw milk cheesemakers. The researchers also emphasized that acidity adjustment—through lactic acid fermentation or direct acidification—plays a critical role in neutralizing the virus.
A warning for consumers and regulators
With H5N1 now detected in dairy cattle across the United States, these findings raise urgent questions about food safety and viral transmission through dairy supply chains. Although no human infections have been definitively linked to contaminated milk or cheese, the study underscores the importance of vigilance. Consumers are urged to choose pasteurized dairy products, while regulators may need to revisit current raw milk cheese aging standards to ensure viral safety, not just bacterial.
The study findings were published in the peer reviewed journal: Nature Medicine.
https://www.nature.com/articles/s41591-025-04010-0
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Medical News.
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https://www.thailandmedical.news/articles/h5n1-avian-flu
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