Could testing the bulk milk supply help track highly pathogenic avian influenza (HPAI)?
USDA and the Food and Drug Administration (FDA) believe it could, and that’s why the two federal agencies have partnered with the executive board for the National Conference on Interstate Milk Shipments (NCIMS) to develop a milk silo sampling study to determine the presence and nationwide prevalence of HPAI in bulk raw cow’s milk.
Since the onset of HPAI in the U.S. dairy cattle herd, there’s been some concern from dairy farmers and dairy processers alike about sharing some of this data . . . especially when it comes to positive test results. To encourage participation in this voluntary program, USDA, FDA, and NCIMS have developed a system in which all raw milk samples would be shipped to a third-party central location to ensure the research is done in a double-blind manner.
A short window for testing
For those who take part, the testing program would take place over a six-week period. Samples of bulk raw cow’s milk would be collected at dairy processing plants prior to pasteurization. To reduce the need for extra labor on this project, the sample collection could take place during the routine regulatory sampling process for Grade A and Grade B milk.
The multi-agency endeavor hopes to gather enough relevant data to make data-driven decisions on the HPAI front. This data could potentially aid in the development of strategies to reduce the transmission and circulation of the virus to better protect the nation’s cattle herds, poultry flocks, and the people who work with them.
To read the joint letter from USDA, FDA, and NCIMS outlining the program, click here.
Ongoing research
It’s important to note that pasteurization has been effective at deactivating the H5N1 virus involved in causing HPAI. FDA released a study on August 13 that found all 167 dairy product samples on stores shelves were negative for viable H5N1 virus.
The study also found that properly aged raw milk cheese sampled from retail shelves had no detectable levels of the H5N1 virus. The group of products sampled included: aged raw milk cheese, pasteurized fluid milk, and products made from pasteurized milk including cheese, cream cheese, butter, and ice cream.
The study did find that 17% of the 167 retail dairy products contained fragments of the H5N1 virus. These results mirror an earlier study in April that found 20% of the products tested had inactive virus particles. In the latest study, FDA emphasized that it tested a wider variety of dairy products in more states compared to the first survey.
