Testing and Variants
Many people are concerned about the new variants of COVID-19 emerging worldwide. Some patients are wondering what our current tests tell us about these new strains. Here are the two most common questions and their answers:
Will the test be positive if I have one of the SARS-CoV-2 variants?
- Yes. The PCR tests being used by SVMC and other labs detect all of the COVID-19 strains in circulation.
- The variants each have slight modifications, through genetic drift, to the ribonucleic acid (RNA) coding for outer protein(s).
- The PCR test detects multiple segments of the RNA, usually around three, not the outer protein itself.
- The RNA of the virus has not mutated to such a degree to evade detection by the PCR tests in use currently.
- New variants are being monitored by the CDC and testing companies in the event that the tests need modification when a new variant is recognized.
Will the test tell me if I have a variant and which one?
- No. The PCR test used by SVMC and other labs does not differentiate between variants of the virus.
- The state of Vermont is sending a sample of positive specimens out for genomic sequencing to differentiate variants. These include a sample of specimens from SVMC.
- Testing of waste water in Burlington shows the presence of two COVID-19 virus mutations that are associated with the B.1.1.7 variant, which was first detected in the United Kingdom.
Have other questions? Ask at firstname.lastname@example.org.
Trey Dobson, MD, is the chief medical officer and an Emergency Medicine physician at Southwestern Vermont Medical Center.