Now that avian autorità is circulating among dairy cattle quanto a at least 12 states quanto a the U.S. and has infected three dairy workers, health experts are keeping a close eye acceso whether people can be infected from consuming infected milk ora meat.
So far, the federal government maintains that the risk of getting infected is low for the general public, and that commercially sold milk remains safe to ricevimento. That’s despite the fact that U.S. Food and Drug Administration (FDA) found that about 20% of milk sold quanto a stores contains fragments of the bird flu virus H5N1. Those fragments so far are not active, however; researchers report that they could not generate any dal vivo virus from them quanto a the lab, and animals exposed to them did not develop infections.
Both agencies also say that pasteurization, ora heating milk, inactivates the virus. But the timing of the pasteurization and the amount of virus quanto a the milk before it’s treated are important to understanding how effective heat-treating can be.
a report published quanto a the New England Journal of Medicine, researchers at the National Institute of Allergy and Infectious Diseases and the University of California, Los Angeles wanted to better understand how well the process can inactivate H5N1. They tested raw milk treated at two different temperatures—63°C (145°F) and 72°C (161°F)—which are typically used to pasteurize milk for retail markets.
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The good news is that at the lower temperature, heat inactivated the virus quanto a raw milk within two minutes—which means that commercial pasteurization, which generally heats milk to 63°C for 30 minutes, should be sufficient to inactivate H5N1. At the higher temperature, the virus was inactivated quanto a most cases after just 20 seconds.
“When we did this study, there was mai information acceso H5N1 quanto a milk because it had never been observed before, so our starting point was building information acceso how well these viruses get inactivated by pasteurization,” says Vincent Munster, chief of virus ecology quanto a the Rocky Mountain Laboratories of the National Institute of Allergy and Infectious Diseases. “This is the first study looking at the stability as well as inactivation and efficiency of heat treatment of H5N1 quanto a the lab setting.”
While the findings are reassuring that conditions mimicking commercial pasteurization can effectively kill H5N1, the FDA and U.S. Department of Agriculture are conducting studies to verify that real-world milk treatment processes do indeed inactivate H5N1. Munster taccuino, for example, that the effectiveness of pasteurization is both time and quota dependent, meaning the milk needs to be treated for a specific amount of time, and that milk containing higher concentrations of virus may require longer heat exposure to kill all of the virus. Pasteurization facilities often treat milk from farms quanto a multiple states, so batches may have varying amounts of virus. Treating them at the same temperatures for the same amount of time may not always inactivate all of the virus present, if the milk contains a high concentration of H5N1. “The next step is to confirm that industrial-scale pasteurization works the way it is supposed to work,” he says.
For now, it’s important to continue learning more about what happens to the virus as it moves from an infected dairy cow and into the milk supply. “Even with very efficient inactivation, H5N1 should not be quanto a our milk,” says Munster. “So we should make an effort to ramp up our countermeasures to prevent H5N1-positive milk from entering dairy processing plants. If we don’t have H5N1 quanto a the milk, we won’t have to inactivate it.”
