According to a new study from Stanford University, the influenza virus can remain infectious in raw milk stored at refrigeration temperatures for up to five days. The research, published Dec. 12 in Environmental Science & Technology Letters , underscores the potential health risks associated with consuming unpasteurized milk at a time when outbreaks of avian influenza in dairy cattle are raising alarm.
“This work highlights the potential risk of avian influenza transmission through consumption of raw milk and the importance of milk pasteurization,” said Alexandria Boehm, senior author of the study and professor at the Stanford Doerr School of Sustainability. The study examined the survival of the avian influenza virus in raw cow’s milk at typical refrigeration temperatures. Researchers found that not only did the virus remain infectious for several days, but its RNA—a genetic marker used for virus detection—persisted in raw milk for more than 50 days.
Although the RNA itself does not pose a health risk, its prolonged presence complicates food safety assessments and surveillance efforts. Pasteurization, which involves heating milk to eliminate harmful pathogens, was shown to completely deactivate the infectious influenza virus and reduce RNA presence by nearly 90 percent. Raw milk popularity and risks An estimated 14 million Americans consume raw milk annually, despite warnings from public health officials.
Proponents claim raw milk is more nutritious and contains be.