CDC updates guidance on SARS-CoV-2 antigen testing

Technical guidance to support effective use of antigen tests in various testing situations was updated this week by the Centers for Disease Control and Prevention (CDC). The guidance summarizes the differences between diagnostic, screening, and surveillance testing and provides links to regulatory requirements. The guidance also provides information to help clinicians recognize potentially false negative or false positive results, noting, “Rapid antigen tests perform best when the person is tested in the early stages of infection with SARS-CoV-2 when viral load is generally highest.” This interim guidance is intended for laboratories and for clinicians who order or perform antigen tests or use their results. (CDC website, 9/4/20)