FACT CHECK: Did The CDC Say PCR Tests Do Not Distinguish Between COVID-19 And The Flu?
A post shared on Facebook claims the Centers for Disease Control and Prevention (CDC) said polymerase chain reaction (PCR) tests do not distinguish between COVID-19 and the flu.
The CDC did not announce that PCR tests could not tell the difference between COVID-19 and the flu. The agency withdrew the emergency use authorization (EUA) request for its PCR test in favor of newer, multiplexed tests.
PCR tests are a form of diagnostic test for COVID-19, according to the Food and Drug Administration (FDA). The Cleveland Clinic describes the tests as the “most accurate and reliable test for diagnosing COVID-19.”
A July 26 Facebook post reads “PCR tests DON’T differentiate between covid and the flu,” and cites the information as coming from the CDC. (RELATED: Did Sweden Stop Using PCR Tests To Diagnose COVID-19?)
There is, however, no evidence the CDC has made such an announcement. Check Your Fact searched the CDC’s website and did not find any evidence that it said PCR tests could not tell the difference between SARS-CoV-2 and the flu. Had the CDC said PCR tests were ineffective, media outlets certainly would have reported on it, yet none have.
The CDC stated in a July 21 announcement it was withdrawing the EUA for its 2019-Novel Coronavirus (2019-nCoV) Real-Time RT-PCR Diagnostic Panel, which was first used in February 2020.
“Although the CDC 2019 Novel Coronavirus (2019 nCoV) Real-Time RT-PCR Diagnostic Panel met an important unmet need when it was developed and deployed and has not demonstrated any performance issues, the demand for this test has declined with the emergence of other higher-throughput and multiplexed assays,” CDC spokesperson Jade Fulce said in an email to Check Your Fact.
The claim appears to stem from a misunderstanding of part of the announcement where the agency stated laboratories and testing sites should use other FDA-authorized COVID-19 tests. It further said laboratories should “consider adoption of a multiplexed method that can facilitate detection and differentiation of SARS-CoV-2 and influenza viruses.” This means that the CDC recommends that laboratories use tests that can look for both viruses, as the CDC’s Real-Time RT-PCR Diagnostic Panel can only detect SARS-Cov-2.
“This is a very accurate test that will save both time and resources for the lab,” Fulce said. “The SARS-CoV-2 (Flu SC2) Multiplex Assay tests for SARS-CoV-2 and for influenza, independently. The test will specify whether a sample tested positive for SARS-CoV-2, influenza or both.”
Other Facebook posts have claimed the FDA withdrew the EUA for PCR tests because it could not distinguish between the flu and COVID-19. This is also false, and the FDA has not made such an announcement, either.
Jim McKinney, a spokesperson for the FDA, told Check Your Fact in an email that PCR tests remain the “gold standard” for COVID-19 diagnosis.
“The FDA has not issued any statement questioning the reliability of PCR test results in general and will continue to consider authorization for validated PCR tests,” McKinney said.