Interium guidance, 25 June 2021Timely and accurate diagnostic testing is an essential tool in preventing and controlling the spread of COVID-19. This document describes recommendations for national testing strategies and the use of PCR and rapid antigen tests in different transmission scenarios of the COVID-19 outbreak, including how testing might be rationalized in low resource settings. All testing should be followed by a strong public health response including isolating those who test positive and providing them care, contact tracing and quarantine of contacts.