FDA and USDA: 20.1% of 144 pasteurized dairy products were PCR + for bird flu with no live virus, while NONE of 23 raw milk cheeses were PCR + nor grew live virus
Bottom line: You can't catch bird flu from dairy products or milk, and RAW milk products were the cleanest
FDA and USDA purchased and tested 144 pasteurized dairy products and 23 raw milk cheeses from around the US with quantitative real time reverse transcription PCR tests seeking evidence of HPAI bird flu viruses. The PCR test only looks for a small, nonviable segment of virus, in this case part of the matrix gene.
Then the researchers tried to grow out virus using embryonated chicken eggs. As in previous tests, none of the RAW or pasteurized dairy products grew out any bird flu virus.
It has been suggested that enzymes in raw milk are antiviral and these enzymes are destroyed by pasteurization.
https://www.medrxiv.org/content/10.1101/2024.08.11.24311811v1
Above is the preprint study that Helen Branswell is reporting on for STAT. Below is the STAT article reporting on it, and below that the abstract from the preprint and the funding statement.
Funding Statement
This research was supported by US Department of Agriculture (USDA)-Agricultural Research Service Project No. 6040-32000-081-00D and the US Food and Drug Administration InterAgency Agreement 6040-32000-081-037I.
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Comment from Dr. Sin Hang Lee, an expert in PCR testing and retired professor of lab pathology at Yale Med School:
It is a very complex technology to detect H5 sequences in dairy products. It needs so many kinds of “software” to assemble sequence fragments. I am not sure if all these “sequences” were truly of viral origin.
There are many LPAI viruses with the H5 gene (H5N2, H5N3, H5N4 H5N5, H5N6…..). We need simple implementable routine sequencing-based tests for cellular H1N1/H5N1 (and other avian viruses) in animal and human specimens. (If you find viral genomic sequence in the cell fraction of the nose or trachea swab, you know the sequence is from the virus. Free viral sequences cannot survive in animal cells.)
Best,
S. H.