The FDA on April 25 reported its national sampling program found inactive fragments of avian influenza in about 20% of pasteurized milk in retail stores. But the agency reaffirmed earlier statements that pasteurization appears to kill the highly pathogenic avian influenza (HPAI), and the country’s milk supply remains safe.
“In addition, several samples of retail powdered infant formula were tested, as well as powdered milk products marketed as toddler formula,” the FDA said on April 26. “All qPCR [quantitative polymerase chain reaction] results of formula testing were negative, indicating no detection of viral fragments or virus in powdered formula products.”
The tested milk came from a nationally representative sample, and most of the positive results came from milk in areas where dairy cows had been infected.
Earlier in the week, the FDA and USDA said “the presence” of the HPAI virus had been detected in milk but they didn’t specify how many positive samples were found.
“Additional testing is required to determine whether intact pathogen is still present and if it remains infectious, which would help inform a determination of whether there is any risk of illness associated with consuming the product,” the agency said. “The FDA is further assessing any positive findings through egg inoculation tests, a gold-standard for determining if infectious virus is present.
“To date, the retail milk studies have shown no results that would change our assessment that the commercial milk supply is safe. Epidemiological signals from our CDC partners continue to show no uptick of human cases of flu and no cases of H5N1, specifically, beyond the one known case related to direct contact with infected cattle. These important efforts are ongoing, and we are committed to sharing results from both the qPCR and egg inoculation tests as soon as possible.”
HPAI had been detected in poultry flocks beginning last October. Then in mid-March it first appeared in dairy cows. On April 2, the food safety agencies reported a human caught the infection, apparently from dairy cattle. And early last week was the first report that HPAI remnants had been detected in pasteurized milk.
