Agriculture Secretary Tom Vilsack is calling on farmers to help stop the spread of H5N1 Highly Pathogenic Avian Influenza. This week, the secretary penned an article detailing what USDA has learned so far.

Vilsack says the risk to human health remains low. However, continued transmission among dairy cattle could cause the virus to adapt. That could potentially make it more likely to spread from mammal-to-mammal, increasing the risk to humans. To stop this, Vilsack is calling on farmers to be diligent with their H5N1 mitigations efforts.

“The more we learn about H5N1, the more we understand that good biosecurity is a critically important path to containing the virus,” he says. “Containing, and eliminating, the virus in our dairy cattle is essential – to protect the health of our herds and flocks, our farmers, our farmworkers, our families, and the rural economy they make possible.”

Biosecurity is a set of practices that limits or prevents the spread of viruses among animals, people and plants. Examples of practices that can limit the spread of H5N1 in dairy cattle include:

What USDA knows so far

Sometime last winter, migrating wild birds infected with H5N1 transmitted the virus to dairy cattle in the Texas panhandle. Cattle from the region were subsequently shipped to various parts of the country, spreading the virus to new states.

As of June 20, H5N1 has been found in 115 dairy herds across 12 states.

While the virus almost always kills birds, it behaves very differently in cattle. Infected dairy cows often have a sudden drop in milk production, stop eating or don’t feel well. However, in most cases, they recover and resume normal milk production within a few weeks.

USDA has determined that the H5N1 virus concentrates in the udders of sick cows and in the cow’s milk, which can contain high loads of the virus. Because of this, even a small splash of infected milk can spread the disease.

“We also came to understand that the disease likely spread between dairies in a community through normal business operations such as the movement of people – unintentionally on items like clothing or shoes – vehicles, and equipment coming and going on a farm,” Vilsack says.

Despite this, he says multiple studies confirm that the U.S. food supply remains safe. USDA scientists are also working to develop an H5N1 vaccine. While that could potentially eliminate the threat to dairy cattle, it will take time to develop an effective vaccine.

How USDA is fighting H5N1

After USDA determined H5N1 spread from the Texas panhandle, the agency issued a federal order requiring all dairy farmers to test their cows before moving them across state lines.  According to Vilsack, more producers testing their cattle allowed farmers and veterinarians to take quick action. The information has also helped scientists better understand how the virus is spreading.

“As producers do more testing, we expect to continue to detect additional dairy herds infected with the virus,” Vilsack says. “This is what USDA expected and is an indication that the system is working as designed.”

To help producers improve their bird flu mitigation efforts, USDA is providing financial support for enhanced biosecurity plans, free H5N1 testing, free shipping to send samples to lab, free veterinary services and free personal protective equipment.

Plans are also in the works for USDA to introduce a program compensating eligible producers with positive herds who experience loss of milk production. It would pay a per cow amount for a set period of time. Producers who want to help with virus containment efforts may also participate in a voluntary H5N1 Dairy Herd Status program.

USDA continues to work with the CDC and FDA to protect farmers and ensure a safe food supply. Vilsack says farmers will need to lead the charge, but they won’t have to do it alone.

“USDA is here to support them every day and we will continue to do all we can to protect animal and human health,” he says. “I am confident that with the right tools and the hardworking spirit of America’s farmers and farmworkers, together we can get it done.”