Drinking raw milk at any time will expose you to dangerous bacteria. But with an unprecedented outbreak of H5N1 avian influenza in U.S. dairy cows, the risks have increased significantly. Health experts have increasingly warned against drinking raw milk during the outbreak, but the extent of this is still unclear.
But raw milk lovers are undaunted by the increased risk. The California-based Raw Milk Research Institute calls this warning “clearly inciting fear” Mark McAfee, the institute’s founder, told the Los Angeles Times this weekend that his customers are actually: Specifically requesting raw milk from H5N1 infected cows. McAfee said his customers believe, without evidence, that drinking high concentrations of the avian influenza virus directly will give them immunity to the deadly pathogen.
Expert Michael Payne told the LA Times that the idea is “like playing Russian roulette with your health.” “It’s ignoring all medical knowledge and common sense and deliberately trying to infect a fly with a known pathogen,” said Payne, a researcher and dairy support coordinator at the Western Institute for Food Safety and Security at the University of California, Davis. added.
Much remains unknown about the biology of avian influenza in cattle. Cows were generally thought to be effectively resistant to H5N1 until March 25, when the U.S. Department of Agriculture confirmed the virus in a dairy herd in Texas.But since then, the Department of Agriculture 42 herds in 9 states Those infected with the virus. Epidemiological data to date suggest that cow-to-cow transmission occurs after a single spillover event, with the 42 affected herds linked by movement of cattle between farms.
So far, limited data on cattle suggest that most cattle develop mild symptoms from infection and recover within a few weeks. Their mammary glands are the main target of the virus. A preprint was published earlier this month Researchers have discovered that cow udders are rich in the molecular receptors that allow avian influenza viruses to cause infection. Additionally, this gland contains multiple types of receptors, including those targeted by human influenza viruses and those targeted by avian influenza viruses. Dairy cows may therefore act as mixing vessels for different types of influenza viruses to reassemble and form new variants that cause epidemics.
The virus appears to be active in cow udders, and researchers have found that raw milk is enriched with high levels of H5N1 virus particles, which are easily spread to other mammals. It seems possible. In a case study last month, researchers reported that a group of about 20 domestic cats developed severe illness after drinking milk from a cow infected with H5N1. Some developed severe neurological symptoms. More than half of the cats died within a few days.
deadly virus
Data on influenza receptors in two animals may explain the differences between cows and cats. Although multiple types of influenza receptors were abundant in the cow’s mammary glands, they were less common in other parts of the cow, such as the airways and brain. This may explain why they are more prone to mild infections. Cats, on the other hand, appear to have a wider range of receptors, and infected cats are more susceptible to the virus. lungs, heart, eyes, brain.
Raw milk enthusiasts claim without evidence that drinking raw milk has health benefits over pasteurized milk, but deny the risk of H5N1 infection. They confidently claim, again without evidence, that the human digestive system destroys the virus. And they stress that there is no documented evidence that humans became infected with H5N1 by drinking contaminated milk.
The latter point, that there is no evidence of milk-borne H5N1 infection, is true. However, this outbreak is the first time that highly pathogenic avian influenza (HPAI) has spread to the mammary glands of dairy cows. This therefore presents the first known occasion for such milk-based transmission to occur.
Before pasteurization became routine in commercial milk production, raw milk was a common source of infection and a reservoir of bacteria. According to the FDA, it started in 1938 due to a milkborne infection. 25 percent of all foodborne illness outbreaks. More recently, milk has been linked to less than 1% of such outbreaks. The Centers for Disease Control and Prevention says that between 1998 and 2018, in areas where raw milk was legally sold, The number of occurrences is 3.2 times than in areas where selling raw milk was illegal.
in Q&A documentThe Food and Drug Administration states, “At this time, the HPAI A (H5N1) virus can be transmitted by ingesting unpasteurized (raw) milk or products (such as cheese) made from raw milk from infected cows.” I don’t know if there is.” However, the agency continues, citing a lack of data and the potential for transmission, the FDA is recommending that all sales of raw milk and raw milk products from cows infected or exposed to H5N1 be discontinued. In general, authorities recommend against consuming raw milk.
Globally, as of March 28, 888 H5N1 infections reported With people from 23 countries. Of these 888 cases, 463 died. This corresponds to a case fatality rate of 52%, but there may be asymptomatic or undiagnosed cases, which could change the case fatality rate. In the United States, only one person is known to have been infected with H5N1 in connection with the dairy cow outbreak, and the farm worker developed conjunctivitis. The man had no respiratory symptoms and recovered. He did not consent to further follow-up, and researchers did not consent to testing his male household contacts to see if they were also infected.
