Testing for COVID-19? Here’s something you should know
Confused between RT PCR, Rapid Antigen, and CBNAAT? Can’t decide which one to go for? Let’s first understand how each one of these work
- RT PCR: RT PCR stands for Real-time reverse transcriptase-polymerase chain reaction, it detects the genetic material RNA in the sample. It is a highly sensitive test and detects even a very small amount of the coronavirus present in the sample. Hence, it is easier to detect asymptomatic and very mildly symptomatic patients through this test. The test is performed by taking nasal and throat swabs which are tested over a few hours. The test results may take up to 24 to 48 hrs. The accuracy rate of this test is very high and hence it is believed to the gold standard for COVID-19 testing. The test is now available at a relatively lesser price point as compared to its initial stages in the year 2020.
- Rapid antigen test: A rapid antigen test detects the presence of COVID-19 antigen in the nasal or throat swab. The test is more accurate when conducted on symptomatic patients. The test might give false-negative results if conducted in the early stages of infection with a lower viral load. Your doctor might even ask you to undergo an RT PCR test if you test negative in a Rapid antigen test. The test results are usually available within 30-45 minutes.
- CBNAAT: CBNAAT stands for Cartridge-based nucleic acid amplification test. The test, though costlier, takes very little time as compared to an RT PCR test with almost the same level of accuracy. The test can be conducted in less than 45 minutes. The sampling mechanism remains the same as the other two types; nasal and oral swab.
To sum it up, all the tests are conducted with the help of swabs taken from the nose or throat. CBNAAT is the fastest, reliable but slightly heavy on the pocket. A rapid antigen test is cost-effective but may give false-negative results and might require a subsequent RT PCR if opined by your doctor. An RT PCR is a sensitive test but might take up to 48 hours to yield a result.