How bird flu virus fragments get into milk sold in stores, and what the spread of H5N1 in cows means for the dairy industry and milk drinkers

The viral fragments were detected using quantitative polymerase chain reaction testing, which is known for its exceptional sensitivity in detecting even trace amounts of viral genetic material. These fragments are only evidence that the virus was present in the milk. They aren't evidence that the virus is biologically active...

https://theconversation.com/how-bird-flu-virus-fragments-get-into-milk-sold-in-stores-and-what-the-spread-of-h5n1-in-cows-means-for-the-dairy-industry-and-milk-drinkers-228689