Fact Check-RT-PCR tests are highly accurate, Delta variant is determined through genomic sequencing

Social media users are falsely claiming that there is no accurate test to detect the COVID-19 virus and therefore no accurate test to detect the Delta variant.

Examples can be seen here and here .

The text in the posts read: “Just a daily reminder: There is still no accurate test to detect C19; therefore, there is no accurate test to detect the “delta” or any variant. The only thing they are testing is your willingness to comply.”


The Centers for Disease Control and Prevention (CDC) says on its website (here) that nucleic acid amplification tests (NAAT) are still considered the “gold standard” in diagnosing SARS-CoV-2, the virus that causes the novel coronavirus (here). This includes the reverse transcription polymerase chain reaction (RT-PCR). It advises that it may be necessary to confirm an antigen test with a NAAT, especially if the test result is inconsistent with clinical context.


Viruses constantly change through mutation, creating new variants, which may have different characteristics. Scientists monitor these changes so that they can learn how they might affect the way the virus spreads, the severity of its effects, how easy it is to detect and whether vaccines will be effective against it.

At the time of publication there were multiple variants of the virus that causes COVID-19 (SARS-CoV-2) in the United States, including the currently dominant Delta variant (B.1.617.2) (here).

Jade Fulce, a spokesperson for the CDC, told Reuters via email in a previous fact check (here) that it is correct that COVID-19 tests for current infection “will not be able to tell you which specific variant you (or a patient) might have”.

However, the CDC uses a process called genomic sequencing to analyze these samples to identify and characterize variants (here).

Genomic sequencing decodes the genes in the SARS-CoV-2 genome to tell scientists which variant might be present in the specimen, allowing them to monitor mutations and learn more about the virus (here).

Reuters Fact Check has previously debunked the claim that the PCR test failed to differentiate between COVID-19 and the influenza virus (here) and the claim that the Delta variant does not exist (here).


False. RT-PCR tests are considered the gold standard in detecting the COVID-19 virus and the Delta variant is determined through genome sequencing.

This article was produced by the Reuters Fact Check team. Read more about our fact-checking work  here  .