FSIS study finds H5N1 viral evidence in muscle of condemned dairy cow
1 of 95 railed cow samples tested at NVSL to date showed positive PCR values
Friday afternoons are always bonanzas for government news releases, and we hit the jackpot today on a long Memorial Day weekend! FSIS released news of a single H5N1 positive PCR finding in muscle tissue from a condemned dairy cow. This significantly expands the “wall of worry” from dairy products to ground beef, although just like milk, heat (cooking) kills the virus. Furthermore, meat exposure is much less likely since cows are only butchered once versus milked twice a day! The article did not disclose CT values on the sample; levels of viral shed will also determine risk to a large extent.
Here is the link:
Updates on H5N1 Beef Safety Studies | Animal and Plant Health Inspection Service (usda.gov)
We need further studies on the duration and level of live virus in beef muscle tissue. While FSIS only tested condemned animals, no one can guarantee that asymptomatic slaughtered animals may not be carrying virus in muscle or lymph tissue at some level. I applaud FSIS for the semi-transparency; however, 1 of 95 condemned dairy animals is actually a somewhat concerning infection rate. Knowing the viral levels (CT value) of the sample(s) would be helpful and may be forthcoming?
USDA’s earlier small study of retail hamburger in an infected state with negative results is not definitive by itself. No one can prove a negative. Today’s positive results will likely lead to more widespread retail PCR “hamburger hunts” for H5N1. Which is why if retail meat positives are found, the “robust inspection system” argument will work about as well for H5N1 as it works for E. coli O157. In today’s molecular diagnostics world, organoleptic assurances are a little too disingenuous for effective food safety communications strategies.
John