The claim: CDC withdraws use of PCR test, admits it can’t distinguish between flu and COVID-19
A widely shared claim on social media has brought the Centers for Disease Control and Prevention’s decision to retire its PCR test for COVID-19 back into the spotlight.
“CDC Withdraws Use of PCR Test for COVID and Finally Admits the Test Can Not Differentiate Between the Flu and COVID Virus,” reads the screenshot of a Gateway Pundit headline posted on Instagram on Dec. 29.
The Gateway Pundit article, posted the same day, refers to the CDC’s decision in July to withdraw the PCR test in 2022 that the agency created. The screenshot was liked more than 1,000 times in less than 24 hours. Other posts also received hundreds of likes in just a few hours.
But the claim badly mangles the facts.
The CDC’s PCR test will be removed from the list of tests under emergency use authorization because the demand for it has decreased with the authorization of other diagnostic tests – not because it confuses viruses. Experts say the test would not show false positives for COVID-19 if the person only had the flu.
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USA TODAY reached out to the user who posted the claim and to Gateway Pundit for comment.
CDC’s PCR test does not confuse COVID-19 and flu
The Gateway Pundit article claims the CDC admitted the soon-to-be-retired PCR test “can not differentiate between the flu and COVID virus.”
It claimed flu cases were so low in 2020, then, because the test was counting flu cases as COVID-19. But that’s nonsense. Gateway Pundit was misunderstanding the use of the term differentiate.
In an August news release, the CDC wrote the PCR test was specifically designed only to detect the viral genetic material of SARS-CoV-2, the virus that causes COVID-19 – not influenza, which causes the flu.
“It does not detect influenza or differentiate between influenza and SARS-CoV-2,” the website states.
In other words, it’s not that the test can’t tell the two apart, it’s that the test was designed only to detect COVID-19. The CDC spelled this one by noting someone with the flu would not create a false positive for COVID-19 with this test.
Experts told USA TODAY in July it’s “technically impossible” for the CDC’s PCR test to confuse SARS-CoV-2 and the influenza virus.
PCR tests identify and amplify converted viral RNA until the virus’s genetic makeup can be detected and analyzed.
In this case, since the CDC’s PCR test was made to only identify SARS-Cov-2, it cannot detect or confuse the genetic sequences of another virus such as influenza, according to Dr. Petros Giannikopoulos, medical director of the Innovative Genomics Institute’s COVID-19 testing consortium.
CDC withdrawing PCR test to focus on other goals
On July 21, the CDC announced it would withdraw the request for an emergency use authorization for the agency-developed PCR test after Dec. 31.
The test will be removed because the Food and Drug Administration, which is in charge of approving the use of medical devices and vaccines, has authorized “hundreds” of other COVID-specific tests similar to the CDC’s, the agency said in an Aug. 2 clarification after the announcement sparked confusion.
“CDC began distributing the CDC 2019 Novel Coronavirus Real-Time RT-PCR Diagnostic Panel to fill a gap,” the release said. “The wide availability of other SARS-CoV-2 diagnostic tests means that the CDC 2019 Novel Coronavirus (2019-nCoV) Real-Time RT-PCR Diagnostic Panel is no longer filling an unmet need.”
The discontinuation, which only applies to the CDC-manufactured test and not other diagnostic tests authorized for use by the FDA, would also let the CDC “focus its resources on public health surveillance testing and other response activities,” according to the release.
Jasmine Reed, a CDC spokeswoman, told USA TODAY in July the agency also wanted to encourage laboratories to start using tests that can detect the influenza virus and COVID-19 in the same swab to conserve time and resources.
The CDC has its own test that can detect and differentiate COVID-19 and the influenza A and B viruses. That test is not being withdrawn.
USA TODAY reached out to the CDC for comment.
Our rating: False
Based on our research, we rate FALSE the claim that the CDC withdrew the use of its PCR test and admitted it can’t distinguish between the flu and COVID-19. The CDC is withdrawing the test, but it has nothing to do with the flu. The agency-created PCR test simply isn’t needed because hundreds of tests from private companies have addressed this need and been approved by the FDA. The CDC test properly showed positive results only for COVID-19; a person with the flu could not test positive for COVID-19 using the CDC test, experts say.
Our fact-check sources:
- The Gateway Pundit, Dec. 29, Huge. CDC Withdraws Use of PCR Test for COVID and Finally Admits the Test Can Not Differentiate Between the Flue and COVID Virus
- CDC, July 21, Lab Alert: Changes to CDC RT-PCR for SARS-CoV-2 Testing
- CDC, Aug. 2, Lab Alert: Clarifications about the Retirement of the CDC 2019 Novel Coronavirus (2019-nCov) Real-Time RT-PCR Diagnostic Panel
- USA TODAY, July 29, Fact check: CDC test doesn’t conflate COVID-19 virus with influenza
- CDC, Oct. 6, Multiplex Assay for Flu & SARS-CoV-2
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