In March 2024, a notable case of highly pathogenic avian flu, also known as H5N1 bird flu, spreading to dairy cows in Texas raised concerns about the safety of dairy products for consumers. Subsequent testing revealed the presence of H5N1 in a few animals and individuals across multiple states, prompting a detailed examination of the potential risks associated with dairy consumption.
Dr. Erica Spackman, a virologist at the U.S. Department of Agriculture in Athens, Georgia, led a study to determine the extent of virus transmission in milk products. Nearly 300 samples from 132 processors were analyzed, and the results, published in the Journal of Virology, confirmed the absence of any infectious virus. Dr. Spackman emphasized that the current sanitation practices effectively eliminate pathogens, including H5N1, during the milk processing stages.
The stringent safety measures in place during milk processing, such as microbiological surveillance and exclusion of milk from sick cows, coupled with the heat treatment during pasteurization, contribute to shielding consumers from potential threats. While avian flu typically spreads among birds and occasionally infects other animals, the detection of H5N1 in dairy cattle marked a novel occurrence.
Following the identification of live virus in raw milk samples, a detailed investigation was conducted by the U.S. Food and Drug Administration and USDA to assess the efficacy of pasteurization in eradicating risks to consumers. Extensive real-time PCR analysis of 297 pasteurized retail milk samples from various states confirmed the absence of live virus in any of the samples, despite the detection of viral genetic material in 20% of them.
Dr. Spackman expressed confidence in the findings, highlighting the crucial role of pasteurization in ensuring the safety of dairy products. The study results provide reassuring evidence of the effectiveness of current safety protocols in safeguarding consumers from unforeseen threats.
