No response returned

The U.S. Department of Agriculture requiring raw, unpasteurized milk samples nationwide to be tested, federal officials announced Friday. 

The move is part of the department's announcement of its "," which builds on previous actions taken for the outbreak of highly pathogenic avian influenza, or HPAI H5N1, in dairy cattle that was , according to a news release from the department.

The bird flu virus has been particularly in California, where nearly 500 of the more than 700 infected U.S. herds have been detected.

Health officials raised the alarm last month after more than 50 human cases of a bird flu variant were confirmed across seven states this year. The virus has infected 57 people in the U.S. this year, including 31 in California, according to the U.S. Centers for Disease Control and Prevention. 

Mild illnesses have been seen in dairy and poultry workers who had close contact with infected animals. In two cases, no known source of the illnesses have been identified, which has worried infectious disease experts about the , which could trigger a pandemic. 

While no cases of bird flu virus have been confirmed in people who drank raw milk, health officials have long because it can contain illness-causing bacteria. Pasteurized milk, which is heat-treated to kill the virus, remains safe to drink. 

Agriculture Secretary Tom Vilsack said in  the new milk testing strategy, which is set to begin the week of Dec. 16, will "give farmers and farmworkers better confidence in the safety of their animals and ability to protect themselves, and it will put us on a path to quickly controlling and stopping the virus' spread nationwide."

According to the release, the federal order includes three new requirements:

In , the USDA started requiring the dairy industry to test milk-producing cows for infections from HPAI H5N1 before they're moved between states.