Dairy Science Weekly


Welcome to ADSA's refreshed newsletter—Dairy Science Weekly—with a new name and look but the same great content as Dair-e-news. Be the first to know about the latest global dairy news, educational industry events, and the newest publications and resources from ADSA leadership and members. Subscribe to get Dairy Science Weekly directly to your inbox every Wednesday.

Opinion and editorial content included in Dairy Science Weekly represent the views of the authors. Publication does not represent endorsement of any position by the ADSA.

Jess Townsend
P: 217.356.3182 x 131

USDA, FDA, and CDC updates on HPAI detections

USDA Updates

The US Department of Agriculture’s (USDA) is adding an additional $824 million in emergency funding from the Commodity Credit Corporation to bolster its efforts and is launching a new Voluntary H5N1 Dairy Herd Status Pilot Program to give dairy producers more options to monitor the health of their herds and move cows more quickly while providing ongoing testing and expanding USDA’s understanding of the disease.

The USDA Animal and Plant Health Inspection Service (APHIS) announced a Federal Order, effective Monday, April 29, 2024, requiring mandatory testing for interstate movement of dairy cattle and mandatory reporting for laboratories and state veterinarians. See below for the current resources:

On the heels of the announcement, APHIS also enhanced its 2013 rule for the official identification of livestock and documentation for certain interstate movements of livestock. The new rule—which applies to all dairy cattle and will take effect 180 days after publication in the Federal Register—requires official eartags to be visually and electronically readable for official use for interstate movement to bolster animal disease traceability in the US.

In an effort to maximize understanding and research on H5N1 in dairy cattle, APHIS made publicly available 239 genetic sequences from the U.S. H5N1 clade influenza virus recently found in samples associated with the ongoing HPAI outbreak in poultry and wild birds, and the recent H5N1 event in dairy cattle. APHIS has also offered virus samples to interested researchers to facilitate epidemiological study and will continue making additional raw genetic sequences available on a rolling basis, which can be found using the search term “WGS of H5N1.”

Stay updated with the latest on their dedicated landing page, which contains recent announcements on HPAI detections in livestock and biosecurity information and other resources updated daily.

CDC Updates

The US Centers for Disease Control and Prevention (CDC) reported a third human case of avian influenza A(H5) virus infection in a dairy worker in Michigan who had work exposure to infected cows. The agency has confirmed the neuraminidase of the virus as N1, and has released the genetic sequence of the Michigan case. Based on the information available so far, this infection does not change the CDC’s current human health risk assessment for the US general public, which the agency considers to be low. The CDC has now developed and posted new consumer and responder resources, including a summary fact sheet of CDC recommendations and resources and an information sheet for dairy farm workers, outlining how infections with A(H5N1) might happen and how to prevent them.

Also of note,

FDA Updates


The US Food and Drug Administration has announced an additional set of results from their national commercial milk sampling study. The study includes 297 total retail dairy samples. New preliminary results of egg inoculation tests on a second set of 201 quantitative polymerase chain reaction–positive retail dairy samples, including cottage cheese and sour cream, in addition to fluid milk, show that pasteurization is effective in inactivating HPAI. This additional preliminary testing did not detect any live, infectious virus.

The USDA’s Food Safety and Inspection Service (FSIS) has also announced results from its testing of retail ground beef. FSIS collected 30 samples of ground beef from retail outlets in the states with dairy cattle herds that had tested positive for the H5N1 influenza virus at the time of sample collection. The samples were sent to the Animal and Plant Health Inspection Service’s National Veterinary Services Laboratories (NVSL) for PCR testing. On May 1, NVSL reported that all samples tested negative for H5N1. These results reaffirm that the meat supply is safe.

Based on the information currently available, our commercial milk supply remains safe to consume due to the pasteurization process and the diversion or destruction of milk from sick cows. Pasteurized milk and properly cooked meat remain safe to consume.

Avian Influenza A In Peer-Reviewed Literature

Avian influenza A viruses in ruminants are not entirely without precedent; a 2008 study experimentally infected bovine calves with HPAI, and a 2019 literature review explored the history of influenza A infections in bovine species. 

In an early-release article in Emerging Infectious Diseases, researchers described a group of about two dozen cats that were fed raw milk from cows with avian influenza on a Texas dairy farm. More than half of the cats became ill and died; two of the deceased cats were tested and found to have been infected with the virus. It’s possible they were sickened by eating wild birds, but raw milk was “a likely route of exposure,” the researchers wrote.

A letter published in the New England Journal of Medicine found that mice that consumed untreated milk infected with H5N1 subsequently became ill with influenza and that small amounts of virus persist in untreated milk for weeks when kept at standard refrigeration temperatures.