The new rules call for testing unpasteurized milk from dairies across the country and for farm owners to provide details that would help officials identify and track cases more easily.
The U.S. Department of Agriculture announced new rules on Friday requiring the testing of the nation’s milk supply for the bird flu virus known as H5N1, nearly a year after the virus began circulating through dairy cattle.
Under the new testing strategy, the department will begin testing bulk samples of unpasteurized milk from dairy processing facilities across the country.
Farmers and dairy processors will be required to provide samples of raw milk on request from the government. The rules also require farm owners with infected herds to provide details that would help officials identify more cases and contacts.
The rules are a departure from the voluntary guidance that the department has issued during the outbreak. Many dairy farms have not complied with voluntary testing of milk or of dairy workers, leaving federal officials in the dark about how widely the virus might have spread.
Many experts in the United States and elsewhere, including with the World Health Organization, have sharply criticized the lack of testing of cattle and of people who may be infected with the virus. The virus does not yet spread easily among people, but every untreated infection is an opportunity for it to gain the ability to do so, experts have said.
The new rules are an attempt to gain control over the outbreak, Agriculture Secretary Tom Vilsack said in a statement.
The strategy “will give farmers and farmworkers better confidence in the safety of their animals and ability to protect themselves,” he said, “and it will put us on a path to quickly controlling and stopping the virus’s spread nationwide.”
The virus has now been detected in 720 herds in 15 states, although experts believe that figure is a significant underestimate, given the lack of mandatory testing. At least 58 people, most of them farm workers, have also been infected.
The agency’s last major mandate on testing came in April, when it issued a federal order requiring that lactating dairy cows be tested for flu before being moved across state lines.
Under the new strategy, the Agriculture Department will monitor bulk milk samples from farms nationwide, and work with state officials to identify infected herds.
The new rules mandate farms to share raw milk samples upon request. The rules also apply to private laboratories and state veterinarians, who will be required to report raw milk samples that contain virus to the Agriculture Department.
The first round of testing under the new rules is scheduled to begin the week of Dec. 16. The program will begin in six states: California, Colorado, Michigan, Mississippi, Oregon and Pennsylvania.