Coronavirus disease 2019 (COVID-19) infection can be diagnosed using a test called polymerase chain reaction (PCR).
What Is the PCR Test for COVID-19 Infection?
Samples are taken from places likely to have the virus that causes COVID-19, like the back of the nose or mouth or deep inside the lungs. After a sample is collected, RNA, which is part of the virus particle, is extracted and converted to complementary DNA for testing. The PCR test involves binding sequences on the DNA that only are found in the virus and repeatedly copying everything in between. This process is repeated many times, with the doubling of the target region with each cycle. A fluorescent signal is created when amplification occurs, and once the signal reaches a threshold, the test result is considered positive. If no viral sequence is present, amplification will not occur, resulting in a negative result.
Should You Be Tested?
Guidelines for testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for COVID-19, continue to evolve as knowledge of COVID-19 improves and availability of testing increases. Currently, testing in India is only performed for individuals when a positive result will change treatment. Testing is also prioritized for people who have a high risk for bad outcomes from COVID-19 infection, such as elderly or immunosuppressed patients, and those with a high risk of exposure and transmission of the disease to other people, such as health care workers. Recommendations for testing are regularly updated by the ICMR.
Dr. Sriharsha Tikka 