Worrying experiments: Raw milk transmits the bird flu virus to mice

-
A recent study revealed a worrying relationship between raw (unprocessed) milk and the H5N1 avian influenza virus.

This discovery raises important questions about the safety of raw milk consumption, especially during periods of bird flu outbreaks.

In the study, scientists studied the effect of raw milk contaminated with the H5N1 virus on mice. The results were alarming, as the mice showed signs of illness shortly after eating it.

High levels of the virus were detected in their respiratory organs and other parts of their bodies, even in the mammary glands of non-lactating female mice.

A team led by virologist Yoshihiro Kawaoka of the University of Wisconsin-Madison concluded: “Data suggest that HPAI type A virus present in untreated milk can infect susceptible animals that consume it.”

These results suggest that consumption of raw milk contaminated with H5N1 can lead to infection of mammals, including humans. While the risk of transmission to humans remains low, the potential consequences are severe enough to warrant caution.

Fortunately, pasteurization, a process that involves heating milk to high temperatures, effectively kills the H5N1 virus. This makes pasteurized milk safe for consumption, even during a bird flu outbreak.

The study also revealed that cooling alone does not guarantee the elimination of the virus. In fact, virus levels in refrigerated and contaminated milk slowly decreased over five weeks, indicating a long period of potential infection.

The researchers explored the effects of pasteurization by heating contaminated milk, and found that virus levels were significantly reduced, although not always completely eliminated.

While the study conditions did not precisely replicate industrial pasteurization processes, the results underscore the critical role of pasteurization in ensuring milk safety.

However, the study appears to confirm that the real risk of H5N1 transmission to consumers lies in raw milk consumption.

"Don't drink raw milk, that's the message," Kawaoka told the New York Times.

There are reasons beyond bird flu to avoid raw milk, as according to a 2022 study from the US Centers for Disease Control and Prevention, raw milk consumption was linked to 228 hospitalizations, three deaths and illness in more than 2,600 people between 1998 and 2018.