COVID-19 has affected many lives in the past year. Thankfully, after various tests and precautions, the number of cases has decreased. One such test that was and is being widely used to diagnose Corona is the RT-PCR Test. This particular test has been very useful in diagnosing not just SARS-CoV-2 but also microbial infection. It is quite a simple test, that is done even in the comfort of your own home.
The cause for COVID 19 is the SARS-CoV-2 Virus. This virus is an RNA virus, meaning it damages a healthy cell to multiple and thrive in the body. The RT-PCR test is used to identify the SARS-CoV-2 RNA virus in the body. A process called reverse transcription is used to detect the virus. Reverse transcription allows the RNA to be converted to DNA.
The RNA virus can be detected during the initial stages of the infection itself. It through respiratory samples such as
- Nasal swabs
- Lower respiratory tracts aspirates
- Bronchoalveolar lavage
- Nasal aspirate etc
The specimens are sent to labs where they are treated with many chemical solutions. These solutions are useful to remove substances like fats, proteins, and draw out only the RNA virus if it is present in the sample.
How do doctors understand the severity of the RNA virus?
The entire setup generally takes 35 cycles – wherein each cycle, new copies of the viral DNA are created from a strand of the RNA virus present in the sample. As more and more copies are created, the marker labels attach to the DNA strands and it releases a fluorescent dye. Computers are used to track the amount of fluorescent in the specimen after each cycle. When the amount of dye exceeds a certain level, the lab technicians proceed to confirm that the virus is present. This method is also useful to understand how intense the infection as the fewer cycles it takes, the more severe it is.
Are the results accurate?
No, there have been incidents of false positives and negatives. However, false-positive results may not have the RNA virus but it could mean that there are other bacterial or co-infections with other viruses. Negative results are combined with observations, patient history and other information etc.
When should you get an RT-PCR test?
You need to get tested for the RNA virus if you show symptoms such as dry cough, fever, fatigue, body ache, loss of taste and smell, chest pain and difficulty in breathing. Additionally, it is responsible for people who travelled, been in a crowded space, come in contact with an infected person to take the test. People who want to reassess themselves after isolating themselves for 14 days also should take a test. The tests are completely safe for all genders and ages. Babies that are weaning, toddlers, kids above the age of 4+ can also be tested without any harm to their health.