A study conducted by researchers at the University of Wisconsin-Madison, published in the New England Journal of Medicine on Friday, highlights the potential risks associated with drinking raw milk containing H5N1 avian flu viruses. The research involved feeding mice milk from H5N1-infected cows, which resulted in severe illness.

While the study cannot definitively prove that consuming raw milk with H5N1 virus would have the same effects on humans, experts emphasize the probable risks involved. Conducting similar studies on humans is not ethically possible.

Michael Osterholm, Director of the Center for Infectious Disease Research and Policy at the University of Minnesota, stated that raw milk is strongly suspected of transmitting H5N1 to animals, and the risk for humans remains unclear. Osterholm, along with other experts in the field, advises against taking chances with raw milk consumption.

Further observations in this study indicate that farm cats have died after consuming contaminated milk from infected cows. Thijs Kuiken, a pathologist at the Erasmus Medical Center in the Netherlands, supports the study's findings and believes that individuals drinking raw milk from infected cows would likely contract systemic diseases.

The Food and Drug Administration (FDA) has long advised against consuming raw milk due to the presence of dangerous pathogens such as E. coli, Salmonella, and Listeria. This advice is reiterated in light of the current outbreak of H5N1 in dairy cattle. Since late March, 58 herds in nine states have tested positive for the virus, with two human infections detected in farm workers.

The senior author of the study, Yoshihiro Kawaoka, a renowned influenza virologist who has extensively studied H5N1, explained that mice were euthanized on day 4 of the study to avoid prolonged suffering. Animal studies involving lethal pathogens aim to prevent unnecessary pain.

The study encompassed various components, including feeding raw milk to mice and simulating different approaches to pasteurization. One method successfully eliminated the virus, while another reduced its levels to a minimum. The researchers acknowledged that their pasteurization methods differed from those used commercially.

Additionally, the researchers stored raw milk containing the virus at refrigerator temperature for several weeks to assess the decline of the virus over time. They found only a slight reduction, suggesting that the virus can remain infectious for several weeks in raw milk stored at 4°C.

Keith Poulsen, one of the authors and director of the Wisconsin Veterinary Diagnostic Laboratory, commented on the study's findings, noting that the flu virus is known to thrive in cold and wet environments.

The study's significant discovery of H5N1 virus in the mammary glands of mice highlights the susceptibility of mammary tissues in dairy cattle. It is observed that infected lactating cows shed high levels of the virus in their milk.

This study contributes to the growing body of evidence that raises concerns about the dangers associated with consuming raw milk potentially contaminated with H5N1 virus. Given the risks posed by this deadly virus and other harmful pathogens, health experts strongly advise against consuming unpasteurized milk.