In experiments, mice get ill from raw milk carrying bird flu virus

Confirming the hazards of ingesting uncooked cow’s milk when the H5N1 avian flu virus is circulating in U.S. dairy herds, researchers discovered that mice fed the milk shortly received unwell.

“Our information point out that HPAI A[H5N1] virus in untreated milk can infect inclined animals that devour it,” concluded a crew led by virologist Yoshihiro Kawaoka, of the College of Wisconsin–Madison. His crew revealed the findings Friday within the New England Journal of Medication.

In late March, researchers first detected traces of H5N1 fowl flu in nasal swabs and milk obtained from U.S. dairy cows. Since then, the outbreak has been detected in lots of dairy herds throughout a number of states.

Up to now, H5N1 doesn’t appear to transmit simply between animals and people: There have been solely two recognized human circumstances of H5N1 an infection linked to the U.S. dairy cow outbreak. Each have occurred in dairy staff who’ve had prolonged, shut contact with the animals.

Specialists additionally imagine the final milk provide to be secure, because the heating concerned in pasteurization kills the virus.

Nevertheless, ingesting unpasteurized “uncooked” milk—a craze amongst a small subset of shoppers—might, in actual fact, run the chance of passing H5N1 to different mammals, together with folks.

To seek out out if that’s true, Kawaoka and his crew gave mice uncooked cow’s milk recognized to be contaminated with the H5N1 virus. The rodents obtained the milk by mouth.

The mice confirmed typical indicators of an infection, resembling “ruffled fur and lethargy” as quickly as in the future after being fed the milk, the researchers reported.

“All of the animals survived till day 4, after they have been euthanized to find out virus titers [levels] in a number of organs,” Kawaoka’s group mentioned.

“We detected excessive virus titers within the respiratory organs [which suggests that infection may have occurred through the pharynx] and average virus titers in a number of different organs, findings in line with the systemic infections sometimes attributable to HPAI H5 viruses in mammals,” the crew reported.

Excessive ranges of virus have been additionally discovered within the feminine mice’s mammary glands, despite the fact that they weren’t lactating, the researchers mentioned.

Based mostly on their findings, the researchers imagine that mammalian an infection with the avian flu virus can occur after consuming cow’s milk containing the pathogen if the milk has not been heat-treated, as occurs with pasteurization.

Individuals who drink uncooked milk might imagine that refrigeration can kill off the H5N1 virus. The researchers investigated that notion, refrigerating the contaminated milk at a temperature of 39 levels Fahrenheit.

Nevertheless, ranges of virus within the unpasteurized milk declined solely slowly whereas stored at this temperature for 5 weeks, suggesting that the “virus might due to this fact stay infectious for a number of weeks” below these circumstances, in response to the researchers.

As for pasteurization, the scientists put uncooked, contaminated milk by heating processes just like these used within the pasteurization course of. They report that ranges of virus have been diminished to undetectable or barely detectable ranges, however in some circumstances not fully eradicated.

Kawaoka’s crew harassed that “the circumstances utilized in our laboratory examine aren’t similar to the large-scale industrial [pasteurization] remedy of uncooked milk.”

Nonetheless, the analysis appears to verify that the true hazard of passing H5N1 onto shoppers lies within the consumption of uncooked milk.

“Do not drink uncooked milk—that is the message,” Kawaoka instructed the New York Instances.

And there are extra causes than fowl flu to keep away from uncooked milk.

In response to one 2022 examine from the U.S. Facilities for Illness Management and Prevention, uncooked milk consumption has been linked to 228 hospitalizations, three deaths and sickness in additional than 2,600 folks between 1998 and 2018.

© 2024 HealthDay. All rights reserved.