Raw Milk with Bird Flu Virus Infects Mice in Study, Reports Reuters

Study Links Consumption of Raw Milk to Bird Flu Infections in Mice

A recent study published in the New England Journal of Medicine has found that feeding raw milk contaminated with bird flu to mice resulted in their infection with the virus. This research adds to the growing concern about the safety of consuming unpasteurized milk.

Bird flu has been responsible for severe or fatal infections worldwide, particularly among those in close contact with infected wild birds or poultry. Experts have long been wary of the virus as a potential trigger for a global health crisis.

This week, U.S. officials confirmed a second human case of bird flu in a dairy worker from Michigan, following its detection in dairy cattle earlier this year. Symptoms in both infected workers were limited to conjunctivitis, commonly known as pink eye.

In the study, researchers from the University of Wisconsin-Madison and Texas A&M Veterinary Medical Diagnostic Laboratory conducted an experiment where they administered raw milk from infected dairy cattle to five mice. The mice exhibited signs of illness, including lethargy, within the first day of exposure. High levels of the virus were detected in the mice’s nasal passages, trachea, and lungs, with moderate to low levels found in other organs, mirroring bird flu infections observed in other mammals.

While the majority of milk consumed in the U.S. is pasteurized, there are 30 states that allow the sale of raw milk, which represents less than 1% of total milk sales nationwide. A survey of pasteurized milk indicated that approximately 20% of samples contained bird flu virus particles.

The study also noted that the levels of the bird flu virus decreased slowly in raw milk stored at refrigeration temperatures.

The research was funded by the National Institute of Allergy and Infectious Diseases, a part of the U.S. National Institutes of Health. The U.S. Food and Drug Administration continues to recommend against the consumption of raw milk, and officials have urged dairy farms to pasteurize milk that is discarded.