A chemical widely used to sterilize medical devices is also used for nasal swabs in COVID-19 testing. But a viral video misleadingly suggests that the swabs are dangerous — saying that the chemical causes cancer and can alter DNA. Experts say the chemical’s use in this context does not pose a threat to human health.
A viral headline shared on social media falsely asserts that the Centers for Disease Control and Prevention changed testing thresholds to “virtually eliminate” COVID-19 cases among vaccinated individuals. That’s wrong. The threshold in question simply applies to whether or not there is enough virus present in a sample for further analysis.
Tests that detect current infections with SARS-CoV-2, the virus that causes COVID-19, are known as viral tests. There are two types: a Nucleic Acid Amplification Test, or NAAT, and an antigen test.
Many of the NAATs use a molecular biology technique known as the polymerase chain reaction, or PCR, to detect even a very tiny amount of the virus in a specimen.
The PCR test takes advantage of some natural features of biology to essentially scan through all of the RNA present in a sample — such as a nasal swab — and search for the presence of coronavirus RNA.
A viral claim on Facebook erroneously tells users that “you will test positive” for COVID-19 if “you’ve gotten flu shots during the past ten years.” Vaccine and infectious disease experts told us that’s false, and the Food and Drug Administration says this hasn’t been observed in any authorized tests.