In brief: A clinical practice article in the New England Journal of Medicine distills available data and clinical experience into a compendium about rapid diagnostic tests for SARS-CoV-2, the virus that causes COVID-19. The appendix identified nearly all FDA-approved rapid diagnostic tests and their efficacy. The list is divided into home-based tests and those for use at designated clinician-run sites.
Author: Dr. Paul Drain, associate professor of medicine and global health at the University of Washington School of Medicine, leads a clinical research group in the International Clinical Research Center to develop and evaluate rapid diagnostic tests for various infectious diseases.
Background: More than 1,000 different COVID-19 diagnostic tests (molecular and antigen) have been commercially developed globally. As of December 2021, the U.S. Food and Drug Administration had granted emergency use authorization to just 28 rapid diagnostic tests, while in the European Union, more than 140 were in use.
For a rapid diagnostic test to receive temporary authorization by the FDA, the World Health Organization and European Union regulatory agencies, it must have at least 80% sensitivity and 98% specificity. Approval by the FDA is also based on a prospective cohort study involving at least 30 people with SARS-CoV-2 infection and 30 people without.
Key points:
- Rapid diagnostics authorized by the FDA are either nucleic acid amplification tests to detect genes or antigen-based immunoassays to detect proteins of SARS-CoV-2.
- Rapid diagnostic tests are approved for use in people with symptoms of COVID-19 and in asymptomatic people who are close contacts of a person with COVID-19 or who have been in a potential high-risk transmission setting.
- Symptomatic people should undergo testing as soon as possible, quarantine while awaiting testing results, and consider retesting if they had a negative rapid diagnostic test, particularly if they have a high probability of infection.
- Asymptomatic people with a known exposure to COVID-19 should undergo testing five to seven days after the exposure. If the rapid diagnostic test is negative, they should undergo testing again two days later.
