Jan. 08, 2025 – the U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) announced that 15 additional states have enrolled in the National Milk Testing Strategy, bringing the total number of states to 28 in roughly one month since the program launched. These 28 states represent nearly 65% of the nation’s milk production. In addition, USDA is sharing updates on its expedited work to support vaccine development for use in poultry and bovine species, as part of a multi-faceted effort to fight the spread of H5N1.

“Across the country, a strong network of public and private veterinarians, as well as state and local agriculture and health officials, have been working hand-in-hand with USDA to make the National Milk Testing Strategy as robust a weapon as possible in our fight against H5N1, and to ensure farmers have the information and tools they need to protect their businesses, their families, their workers, and ultimately their communities,” said Agriculture Secretary Tom Vilsack. “USDA remains fully committed to working with farmers and our public health partners to evolve our strategy based on our latest findings so we can keep people and animals safe from this virus.”

Update on the National Milk Testing Strategy and on Detections of H5N1 in Dairy Cows

Jan. 08, 2025, USDA is announcing the third tranche of states that are enrolled in the National Milk Testing Strategy, under which USDA and state and federal partners will gain a clearer picture of the presence of H5N1 among dairy herds in the United States to help inform the strategy and overall response efforts to prevent further spread of the virus. The 15 states enrolling in the strategy today include: Alabama, Arizona, Delaware, Iowa, Georgia, Kansas, Minnesota, New Jersey, New Mexico, Nevada, Oklahoma, Rhode Island, Tennessee, Utah, and Virginia. The addition of 15 states brings USDA closer to conducting mandatory, nationwide bulk milk surveillance in all 48 contiguous states.

Also in the past 30 days, USDA has identified H5N1 detections in dairy herds in two states, California and Texas, with Texas’ most recent detection reported on Dec. 13, 2024. As of Jan. 8. 2025, California and Texas are the only states with known active detections, though the National Milk Testing Strategy may reveal additional herds over time. However, testing to date, including early NMTS testing, has so far reaffirmed the absence of H5N1 in other states and has not yet led to new detections.

In December 2024, USDA announced two earlier tranches of enrolled states, including California, Colorado, Michigan, Mississippi, Oregon, and Pennsylvania, which enrolled on December 6, 2024; and Indiana, Maryland, Montana, New York, Ohio, Vermont, and Washington, which enrolled on Dec, 17, 2024. USDA continues to work directly with states to bring them on board as quickly as possible while also accommodating state-specific needs based on their infrastructure, state personnel availability, and other considerations.

The National Milk Testing Strategy involves five stages that describe the state’s testing activity and the presence of H5N1 in that state. Of the 28 states enrolled as of today, 11 states are considered to be in Stage 2, meaning they have state-level bulk tank sampling programs already underway. California is considered to be in Stage 3, meaning that it is an affected state that has rapid response measures in place to address detections. Two states are in Stage 1, meaning that silo testing is underway or is set to begin imminently. As new states join and initiate testing, USDA will update their status on its National Milk Testing Strategy website and map linked here.

Testing results from the National Milk Testing Strategy will be included in the routine testing reports shared by APHIS. Since the beginning of the outbreak in March 2024, over 110,000 samples have been tested through USDA’s National Veterinary Services Laboratory (NVSL) and the National Animal Health Laboratory Network (NAHLN), ranging from milk tests that represent multiple herds to individual test from wild or domestic animals. This testing is provided at no cost to producers and, prior to the launch of the National Milk Testing Strategy, had included at least one test from each of the 48 contiguous states. Positive detections are shared in real time with the U.S. Centers for Disease Control and Prevention through shared information systems, and whole genome sequences are uploaded to the public databases GISAID (the Global Initiative on Sharing Avian Influenza Data) and the National Center for Biotechnology Information (NCBI) Sequence Read Archive (use search term “WGS of H5N1”).

All newly affected herds, including any that are detected through the National Milk Testing Strategy, are reported on the website on the HPAI confirmed cases in livestock map. This interactive map shows known active detections in livestock as well as past detections; hovering over each state will show more information about the date of the state’s most recent detection and the total number of herds that were affected. The map can be adjusted to show detections over the past 30 days or over the course of the outbreak.

In addition to the Dec. 6 Federal Order issued in April 2024, requiring the testing of all lactating dairy cows prior to interstate transfer, samples are also routinely collected through the Dairy Herd Status Program, which currently includes herds in 18 states; under testing programs that some states have designed pursuant to their unique authorities; prior to intrastate movement to fairs, exhibitions, or sales as part of state testing programs; or for producers interested in learning the status of their livestock herds.

NAHLN is a partnership of Federal, state and university-associated animal disease diagnostic laboratories that provides ongoing animal disease surveillance. Because of its network structure, NAHLN labs are able to carry out testing from neighboring states and therefore meet the diagnostic needs of this specific disease outbreak and the National Milk Testing Strategy.

More information about the NMTS and states conducting testing under the strategy can be found in the National Milk Testing Strategy.