By Amy Orciari Herman at Journalwatch
The FDA is alerting healthcare providers that rapid antigen tests for SARS-CoV-2 may yield false-positive results — especially when users do not follow the tests' instructions.
The agency emphasizes the importance of storing the test components properly — for example, the cartridge should not be stored in the open before use, as this may impair the test's performance. In addition, results should be read only at the time the instructions specify; reading them too early or too late could lead to inaccurate results.
The FDA also recommends the following:
Take into account the CDC's considerations for using antigen tests in nursing homes (see link below) and other locations. Performing RT-PCR within 48 hours to confirm any positive result may be advisable, especially in geographic areas with low COVID-19 prevalence (the positive predictive value of the test varies according to local COVID-19 prevalence).
Be careful to avoid cross-contamination between patient specimens. Clean the workspace properly and always change gloves between patients.