Video: Bird-flu virus in raw milk damages multiple organs in mice

A study published on Friday, May 24, revealed that unpasteurized milk contaminated with the bird flu virus H5N1 can make mice sick and damage their organs when consumed. This research follows the detection of the bird flu virus in dairy herds across nine states in the United States.

The findings add to the evidence suggesting that virus-infected raw milk may not be safe for mammals, particularly humans. Virologist Yoshihiro Kawaoka, who led the study at the University of Wisconsin, Madison, emphasized, “Don’t drink raw milk — that’s the message.” In the U.S., most commercial milk is pasteurized.

The Food and Drug Administration (FDA) has found traces of the virus in 20 percent of dairy products sampled from grocery stores nationwide. However, officials have noted that no infectious virus has been detected in these samples, and pasteurized milk remains safe for consumption.

Dr. Nahid Bhadelia, Director of the Boston University Center on Emerging Infectious Diseases, told The New York Times that these findings could have global implications. She pointed out that if the outbreak spreads among cows, many rural communities worldwide that consume unpasteurized milk could be at risk.

In conducting the study, Dr. Kawaoka and his team tested milk samples from an affected dairy herd in New Mexico. They found that the virus levels slowly declined in a sample stored at 4 degrees Celsius, indicating that H5N1 could persist in refrigerated raw milk for several weeks. The results of the study were published in the New England Journal of Medicine.

Mice that consumed the contaminated milk became ill, exhibiting symptoms such as ruffled fur and lethargy.

Additionally, the U.S. Department of Agriculture (USDA) reported on May 24 that bird flu was detected in beef for the first time. Officials stated that the meat from a single sick dairy cow did not enter the country’s food supply, ensuring that beef remains safe to eat. The virus was discovered during tests on 96 dairy cows that were diverted from the supply chain after federal inspectors identified signs of illness during routine carcass inspections at meat processing plants.