Testing for COVID-19

Abstract

Accurate diagnostic tests that provide results in a timely manner are essential for the clinical and public health management of COVID-19 disease. The choice as to which test to use will depend on the clinical presentation and the stage of the illness. Nucleic acid tests, using real-time reverse transcriptase-polymerase chain reaction, are the most appropriate for diagnosing acute infection. Combined deep nasal (or nasopharyngeal) and throat swabs are the preferred sample. Serology can be used to diagnose previous infection, more than 14 days after the onset of symptoms. Antigen tests are in development and their role is not yet defined. Interpretation of results must take into account the pre-test probability of the patient having the disease. This is based on their clinical presentation and epidemiological risk.