The FDA alerted labs Nov. 3 of the possibility of false positives with COVID-19 antigen tests.
The agency said it is aware of reports of false positive results associated with antigen tests used in nursing homes and other settings and is monitoring reports about device safety and performance.
To combat false positives, the FDA suggests routine follow-up testing with molecular tests. Improper storage of test components can affect test performance, the FDA stated.
The FDA also said that reading test results at the wrong time can result in false positives or negatives. Insufficient cleaning of the workspace or inappropriate use of personal protective equipment can also cause cross-contamination, which could lead to false positives, the agency said.
Read the FDA's full alert here.