On June 30, the federal Centers for Disease Control and Prevention issued updated guidelines on reopening schools, including information on when to test students who display no symptoms of the coronavirus.

Testing to diagnose COVID-19 is one component of a comprehensive strategy and should be used in conjunction with promoting behaviors that reduce spreadmaintaining healthy environmentsmaintaining healthy operations, and preparing for when someone gets sick, the CDC said.

The CDC said its guidance is meant to supplement — not replace — any state or local regulations. Implementation should be determined by what is feasible, practical, and acceptable and be tailored to the needs of each community.

The federal guidance, Interim Considerations for K-12 School Administrators for SARS-CoV-2 Testing, updates and refines some of the CDC’s earlier statements about how to open schools safely.