The U.S. Food and Drug Administration (FDA) has detected genetic evidence of H5N1 avian influenza in the country’s milk supply. However, the agency says its tests cannot tell if the contamination was from a live virus or fragments that had already been destroyed by pasteurization. The FDA maintains that the U.S. milk supply is still safe to drink because of pasteurization efforts and because it has been intercepting and preventing known contaminated milk from entering the supply chain. The agency says nearly 99% of U.S. milk farms follow its pasteurization ordinances.
The FDA and other regulators are busy testing milk “along all stages of production” for H5N1 and other pathogens. The agency says it is testing milk samples in the same conditions that commercial dairy farms prepare and pasteurize milk in. It is also testing milk that’s already made it to store shelves as well as other dairy products such as cream and whole milk.
Based on available information, pasteurization is likely to inactivate the virus, however the process is not expected to remove the presence of viral particles. Therefore, some of the samples collected have indicated the presence of HPAI using quantitative polymerase chain reaction (qPCR) testing.
