The Food and Drug Administration said Tuesday that it had tested milk samples throughout the dairy production process and confirmed the detection of virus particles “in some of the samples,” but it declined to provide details.
The presence of genetic fragments of the virus in milk is not unexpected. Pasteurization generally works to inactivate pathogens, said Jennifer Nuzzo, director of the Pandemic Center at the Brown University School of Public Health. Typically, this doesn’t remove genetic material, Nuzzo said, but usually renders pathogens incapable of harming people.
Most concerning, however, “is that it is showing up in many more samples, which means the infection is more widespread in dairy herds than we thought,” said a public health official, who ‘is expressed on condition of anonymity to share information not yet. released.
In a four-page statement, the FDA said some of the samples collected “indicated the presence” of the avian flu virus based on tests that detect virus particles but do not distinguish whether they are active or dead. The discovery of the virus “does not mean that the sample contains an intact infectious pathogen,” the agency’s statement said.
Additional laboratory tests are underway to cultivate the virus in cells and in fertilized eggs, the latter being the “gold standard” for sensitive detection of active, infectious virus, the FDA said. “It is important to note that additional testing is needed to determine whether the intact pathogen is still present and whether it remains infectious, which determines whether there is a risk of illness associated with consumption of the product,” it says. the FDA press release.
FDA officials said results were expected in the coming days or weeks.
“So far, we have not seen anything that would change our assessment that the commercial milk supply is safe,” the agency said in its statement.
Officials and experts did not have further details on the number of milk samples positive for avian flu particles or the origin of the samples.
Although this strain of avian flu has been circulating for more than 20 years, its spread among cows has caused great concern, surprising even longtime observers of the virus. More than two dozen livestock herds in at least eight states have been infected with bird flu since March 25, prompting investigations by federal and state authorities.
For weeks, key federal agencies have expressed confidence in the safety of the commercial milk supply, including pasteurized products sold in grocery stores. The FDA highlighted data showing that pasteurization inactivates other viruses and pointed to studies showing that the process of pasteurizing eggs – which occurs at a lower temperature than that used for milk – inactivates avian flu highly pathogenic.
The International Dairy Products Association, which represents the nation’s dairy manufacturing and marketing industry, said the viral fragments are “nothing more than proof that the virus is dead.”
“Milk and dairy products produced and processed in the United States are among the safest in the world,” spokesman Matt Herrick wrote in an email, adding that “the viral fragments simply indicate that pasteurization is doing its job effectively and protects our commercial milk supply.” »
In recent weeks, several experts have expressed confidence that the pasteurization process ensures there is no threat to the security of the country’s milk supply, but said the federal government would still need to conduct testing to confirm that this is indeed the case.
Influenza is a “pretty weak virus,” meaning it’s “pretty easily inactivated,” said Richard J. Webby, a virologist at St. Jude Children’s Research Hospital. “But it’s something that needs to be tested.”
A case of bird flu was reported in a Texas farmworker in recent weeks, marking only the second human case of bird flu in the United States.
So far, the virus has not acquired the ability to spread effectively in humans.
But because it is capable of jumping from animal to animal, the chances of it mutating will cause sustained person-to-person transmission – a development that could fuel a pandemic.
State health officials tested 23 people with flu symptoms, but only A Texas dairy worker tested positive during the current outbreak. Continued monitoring of emergency room visits and flu testing in areas where avian flu has been detected has not revealed unusual trends in flu-like illness or eye inflammation, the only symptom experienced by the dairy worker, according to officials at the Centers for Disease Control. and Prevention, which states that the risk of bird flu to the general public remains low.
The absence of new human cases is a good sign, health officials say.
The key to containing the epidemic lies in livestock herds. Testing on cows is voluntary. U.S. Department of Agriculture protocols limit testing to cows with specific symptoms and limit the number of tests per farm.
News Source : www.washingtonpost.com
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