The U.S. Centers for Disease Control and Prevention is urging health care workers to accelerate bird flu testing for patients hospitalized with flu symptoms.

The Centers for Disease Control and Prevention says hospitals treating people for the flu should test them for avian influenza within 24 hours.

The agency is advising enhanced safety measures in Minnesota and South Dakota, where turkey flocks with more than 500 birds should be isolated, monitored and tested for bird flu within 72 hours before going to slaughter,