The Food and Drug Administration (FDA) is alerting clinical laboratory staff and health care providers regarding the risk of false negative results with any severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test if a mutation occurs in the part of the virus’ genome assessed by that test.
The FDA has identified 3 molecular tests that have received Emergency Use Authorizations (EUAs) that may be impacted by SARS-CoV-2 genetic variants. These include the Accula SARS-Cov-2 Test (Mesa Biotech Inc), the TaqPath COVID-19 Combo Kit (Thermo Fisher Scientific, Inc) and the Linea COVID-19 Assay Kit (Applied DNA Sciences, Inc). According to the FDA, the Accula SARS-Cov-2 test performance may be impacted when a SARS-CoV-2 patient sample with a genetic variant at position 28881 (GGG to AAC) is tested; however, the impact does not appear to be significant. Additionally, while both the TaqPath and Linea tests may have significantly reduced sensitivity due to certain mutations, the tests are designed to detect multiple genetic targets and overall test sensitivity should not be impacted.
The FDA is advising clinical laboratory staff and health care providers who use SARS-CoV-2 tests to be aware of potential false negative results due to genetic variants of SARS-CoV-2. Retesting patients if COVID-19 is still suspected after receiving a negative test result is recommended.
Any adverse events or suspected adverse events including performance issues experienced with molecular tests for detection of SARS-CoV-2, should be reported to the FDA’s MedWatch program.
Genetic variants of SARS-CoV-2 may lead to false negative results with molecular tests for detection of SARS-CoV-2 – letter to clinical laboratory staff and health care providers. [press release]. Silver Springs, MD: U.S. Food and Drug Administration; January 8, 2021.