Traces of Bird Flu Found in 20% of U.S. Commercial Milk Samples

A national survey found traces of bird flu in about 20% of commercial milk in the United States. The greatest proportion of positive tests came from areas with herds infected with the virus, according to the U.S. Food and Drug Administration (FDA).

While the discovery might be a source of concern for many, regulators said there was no evidence at this time that contaminated milk posed any danger or that a live virus was present. Late Thursday, the FDA said they needed additional testing to determine whether the intact pathogen was present in the milk and whether it was still infectious.

Earlier this week, the FDA said that milk heated to a specific temperature was safe for human consumption since harmful bacteria and viruses are heat labile. 

"To date, the retail milk studies have shown no results that would change our assessment that the commercial milk supply is safe," said the FDA in its latest update.

Health authorities maintain that commercial milk supply remains safe

Joining the FDA to declare commercial milk supply safe for human consumption is the U.S. Department of Agriculture (USDA). The agency said the available information at the moment shows that commercial milk supply is safe because they undergo a pasteurization process and that milk from sick cows is diverted and destroyed.

According to the USDA, no fewer than eight states in the United States have confirmed cases of bird flu in 33 herds of dairy cattle. So far, only a Texas farm worker has tested positive for bird flu. The patient presented symptoms of conjunctivitis, an irritation of the eyes that causes redness and discomfort.

Citing epidemiological signals at the U.S. Centers for Disease Control and Prevention (CDC), health regulators confirmed that there were no spikes in human cases and no cases of H5N1 have been reported beyond the index case in Texas. 

FDA’s further assessment for viable cells in commercial milk involves egg inoculation tests which is the confirmatory test for viable viral cells.