Published: Friday, May 24, 2024
Our data indicates that HPAI A[H5N1] A team of virologists led by Yoshihiro Kawaka of the University of Wisconsin-Madison concluded that untreated milk could infect animals susceptible to infection. The findings were published in the New England Journal of Medicine by his team on Friday.
Researchers first detected H5N1 bird influenza in late March on nasal swabs from U.S. milk cows. The outbreak has spread to many dairy cows in multiple states.
Only two human cases of H5N1 have been linked to the U.S. outbreak of dairy cows. The two cases have both occurred in dairy workers with extended and close contact to the animals.
Pasteurization, which involves heating the milk to kill the virus, is also considered safe by experts.
Drinking unpasteurized, “raw” milk, a trend among a select group of consumers, may in fact increase the risk of spreading H5N1 virus to other mammals including humans.
Kawaoka’s team tested this by giving mice milk that was known to contain the H5N1 virus. The milk was given to the rodents by mouth.
Researchers reported that the mice displayed typical signs of infection such as “ruffled hair and lethargy”, as early as one day following the feeding of milk.
“All animals survived until the fourth day, when they were euthanized for virus titers [levels] “Kawaoka’s group claims that the disease affects multiple organs.”
We detected high virus titers within the respiratory organs [which suggests that infection may have occurred through the pharynx] The team found that the HPAI H5 virus causes systemic infections in mammals.
Researchers found high levels of virus in the mammary glands of female mice, even when they weren’t lactating.
According to their findings, researchers believe that consuming milk containing the pathogen can cause mammalian infections with the avian influenza virus if it has not been heated, like with pasteurization.
Some people who drink raw dairy products may think that refrigeration will kill the H5N1 strain. Researchers tested this theory by refrigerating infected milk to a temperature 39 degrees Fahrenheit.
Researchers found that levels of virus in unpasteurized dairy products declined slowly when kept at the same temperature for five consecutive weeks. This suggests that “virus could remain infectious for several more weeks” under such conditions.
Scientists used similar heating methods to pasteurize raw milk infected with viruses. The scientists report that the virus levels were reduced to barely detectable or undetectable levels but not eliminated in all cases.
Kawaoka’s team stressed that “the conditions used in laboratory studies are not identical to large-scale industrial processes [pasteurization] “Treatment of raw milk”
The research suggests that raw milk consumption is the most likely source of H5N1 transmission to consumers.
Kawaoka, a New York Times reporter, said: “Don’t consume raw milk.”
Raw milk is not only harmful for bird flu.
A study by the U.S. Centers for Disease Control and Prevention in 2022 found that raw milk consumption was linked to 228 hospitalizations and three deaths, as well as illness, among more than 2,600 individuals between 1998 and 2018.