WASHINGTON DC, USA — The U.S. Food and Drug Administration, FDA, announced Tuesday, April 24, 2024, that traces of the bird flu virus were found in samples of pasteurized milk, although the agency reaffirms that the milk remains safe to consume.
The detection follows recent outbreaks of the H5N1 bird flu strain in dairy cow herds across eight states, marking the first such occurrence in cattle.
The virus fragments were identified through PCR testing, which identifies genetic material but does not confirm the presence of a live, infectious virus.
“Based on available information, pasteurization is likely to inactivate the virus, however, the process is not expected to remove the presence of viral particles,” the FDA stated in a forthcoming public release.
Currently, the FDA, in collaboration with the Centers for Disease Control and Prevention (CDC) and the U.S. Department of Agriculture (USDA), is conducting further studies to confirm the safety of the milk.
These include egg inoculation tests, a method deemed the gold standard for assessing infectivity, where a chicken egg is injected with the milk sample to monitor for virus replication.
Michael Osterholm, a renowned infectious disease expert, commented on the findings, emphasizing the effectiveness of pasteurization in neutralizing pathogens like E. coli and listeria found in milk.
“If you tested most milk, you’d find E. coli and listeria and other things in it, too, but they’d all be dead,” Osterholm noted, suggesting no immediate risk from the influenza standpoint.
Despite the reassurances, the USDA has faced criticism for a perceived lack of detailed information regarding the spread of the virus in dairy farms.
“We have a need for a lot of additional information that hasn’t been forthcoming,” Osterholm added, highlighting a gap in epidemiological data from affected farms.
The FDA has advised milk producers to take special precautions when discarding milk from infected cows to prevent further spread of the virus.
Meanwhile, the only human infection reported during this outbreak was a mild case of conjunctivitis in a Texas dairy worker, with no other unusual illnesses reported among people thus far.
Health officials remain vigilant due to the bird flu’s high mortality rate and potential to mutate into a form more transmissible between humans, although no such mutation has been observed to date.
