People shouldn't drink raw milk in an attempt to gain immunity from bird flu, health experts have warned.
These warnings follow news that a bird flu subtype called H5N1 was found in cattle herds across the U.S. and reports that the virus has been detected in unpasteurized, or raw, milk samples collected from sick cows.
Since March 25, shortly after news of the cow infections first came to light, weekly sales of raw milk have increased by as much as 21% compared with previous years, the market research firm NielsenIQ revealed to PBS. Anecdotally, farmers have reported that consumers are seeking raw milk to potentially gain immunity from H5N1.
However, experts have warned that this apparent uptick in raw milk consumption could harm individuals' health in multiple ways and also increases the possibility that the bird flu virus could spill over to humans.
"Deliberately consuming raw milk in the hope of becoming immune to avian influenza is playing Russian roulette with your health," Mike Payne, a researcher at the Western Institute for Food Safety and Security at the University of California, Davis, told the LA Times. "Deliberately trying to infect yourself with a known pathogen flies in the face of all medical knowledge and common sense."
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H5N1 is a subtype of highly pathogenic avian influenza (HPAI), a type of flu that causes severe disease and death in birds. The virus typically causes outbreaks in poultry and can be carried by wild birds that don't necessarily get sick. However, a recent outbreak has been spreading among mammals. In the past few years, the virus has infected at least 48 mammal species, including foxes, skunks, raccoons, seals and polar bears.
The virus has also made its way to dairy cows, infecting at least 46 herds across nine U.S. states so far, according to the U.S. Department of Agriculture. Bird flu viruses like H5N1 can very rarely jump to people, and in the current cow outbreak, there's been one probable case of cow-to-human transmission.
However, health officials say that the risk of the virus to the general public remains low. This is in part due to the pasteurization process, which limits exposure by destroying pathogens in milk before it's sold commercially. Researchers are still studying possible ways that the virus passes from birds to cows, but it's believed that the jump was made when infected wild birds came into contact with water and food that the cows consumed.
The U.S. Food and Drug Administration (FDA) has stated that there isn't enough evidence to know if H5N1 viruses can be transmitted to people through unpasteurized milk and dairy products. Due to having limited information on the potential for infection, the FDA recommends against consuming these products.
Raw milk can also carry disease-causing microbes such as Salmonella and Listeria monocytogenes, so experts consider it risky to consume even outside the context of bird flu. Notably, between 1998 and 2018, 202 outbreaks of illness — most of them bacterial in nature — were linked to drinking raw milk, leading to 2,645 illnesses and 228 hospitalizations in the U.S., according to the Centers for Disease Control and Prevention (CDC).
Yet despite these cautions, raw milk proponents remain uncowed.
In a blog post, the California-based Raw Milk Institute (which claims that pasteurized milk is allergenic to consumers) has described the warnings from health experts as "clearly fearmongering." Mark McAfee, the institute's founder and the owner of Fresno's Raw Farm, told the LA Times that his phone has been ringing off the hook with "customers asking for H5N1 milk because they want immunity from it."
As of now, there have been no reported cases of human-to-human transmission of the H5N1 virus, meaning it can't yet spread easily from person to person. But concerns remain that increased exposure to humans could pressure the virus to gain the necessary mutations for this leap to occur.
Between 2003 and 2014, H5N1 has infected nearly 890 people and caused 463 deaths in 23 countries around the globe, placing the estimated fatality rate at 52%, according to the World Health Organization. Such cases have primarily been reported in connection with people having direct contact with infected animals.
The CDC notes that while some cases of bird flu cause no or few symptoms, others have reported colds, coughs as well as fevers, and the disease can sometimes be life-threatening without medical treatment.
This article is for informational purposes only and is not meant to offer medical advice.
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