The FDA has confirmed that some pasteurized milk sold in the U.S. is possibly contaminated with bird flu fragments.
On Tuesday, April 23, the US Food and Drug Administration reported the detection of H5N1 avian influenza viral particles in retail milk, yet maintains its stance on milk safety.
The FDA attributes this finding to sensitive lab tests, suggesting these particles are likely remnants from pasteurization and unlikely to pose infection risks, though further testing is underway for confirmation.
Bird Flu Fragments in US Milk
The Food and Drug Administration (FDA) recently revealed that there are present fragments of the bird flu virus in select samples of pasteurized milk within the United States.
Despite this finding, the FDA assures consumers that the milk remains safe for consumption, pending comprehensive study results. These viral fragments were uncovered during routine testing of pasteurized milk samples, employing the Polymerase Chain Reaction (PCR) testing method designed to detect genetic material. However, a positive PCR result does not indicate the presence of live, infectious virus.
The FDA's stance on the safety of commercial milk remains steadfast, with pasteurization likely deactivating the virus while not eliminating viral particles entirely. This assurance is part of the FDA's ongoing investigation into the effectiveness of pasteurization in neutralizing bird flu within cow milk, with conclusive findings expected within the coming weeks.
In its testing procedures, the FDA utilizes egg inoculation tests, recognized as the benchmark for assessing a sample's infectious potential. This involves injecting a small amount of infected milk into a chicken egg and monitoring any active virus replication.
The agency reaffirms the reliability of these egg inoculation tests in determining the viability and infectiousness of a virus, providing critical insights into public health safety measures.
Comprehensive study results are forthcoming, contributing to the ongoing assessment of the safety of the commercial milk supply.
Through these rigorous testing methods and ongoing research efforts, the FDA aims to uphold consumer confidence in the safety and integrity of pasteurized milk products, ensuring robust public health standards are maintained.
In response to the initial results, Michael Osterholm, an expert in infectious diseases and the director of the Center for Infectious Disease Research and Policy at the University of Minnesota, expressed his lack of astonishment.
He said, "If you tested most milk, you'd find E. coli and listeria and other things in it, too, but they'd all be dead. Pasteurization doesn't take them out, it just kills them."
This indicates that although detectable, non-viable particles are improbable to induce illness in individuals.
H5N1 Bird Flu in Cows
Less than a month ago, the emergence of the H5N1 bird flu strain among dairy cow herds across multiple states marked a significant development. Subsequently, the virus has been identified in herds spanning eight states.
Collaborating closely, the FDA, Centers for Disease Control and Prevention (CDC), and the U.S. Department of Agriculture (USDA) are diligently investigating this outbreak.
The USDA's proactive approach not only mandates reporting of H5N1 in poultry but also incentivizes prompt reporting of any signs of illness in flocks.
Additionally, it financially compensates producers for the disposal of affected birds and eggs, fostering transparency and cooperation among farmers, notes Dr. Michael Osterholm, who leads the Center for Infectious Disease Research and Policy at the University of Minnesota.
While the USDA encourages farmers to report sick cattle to state animal health authorities, widespread screening of both cattle and individuals in their proximity for the infection remains limited due to consent requirements. Discussions include the possibility of testing wastewater in outbreak areas.
In lieu of extensive screening, the CDC relies on monitoring emergency department and flu testing data in regions with H5N1 presence among dairy cattle. They are vigilant for any unusual patterns indicating flu-like illness or conjunctivitis. So far, surveillance data indicate no unexpected trends or heightened activity related to H5N1.
According to CDC spokesperson Jason McDonald, 23 individuals with exposures to H5N1 have undergone testing, including one positive case in Texas from earlier.
However, no other cases have been detected in the current outbreak, ang the FDA is maintaining a cautious yet vigilant stance amid ongoing monitoring efforts.
