COVID-19 Update: How Does the Test for Coronavirus Work In India? Is It Successful?
The test which is commonly used for the detection of Influenza A, Influenza B and H1N1 virus, is conducted using a swab from the back of the throat, by a saliva sample, or liquid sample from the lower respiratory tract, as per the report.
The Indian Council of Medical Research (ICMR) has said that all of its designated labs will conduct the real-time polymerase chain reaction (PCR) test. The test which is commonly used for the detection of Influenza A, Influenza B and H1N1 virus, is conducted using a swab from the back of the throat, by a saliva sample, or liquid sample from the lower respiratory tract, as per the report.
Coronavirus: PCR test
As per the report, in this test, a technique is used to duplicate a segment of the patient’s DNA. The word ‘polymerase’ denotes the enzyme which creates these copies. The chain reaction is referred to how the segment of the DNA gets copied exponentially. Here, one fragment copies into two, two fragments get copied into four and it goes on. However, if viruses which are made of RNA, like the SARS-COV-2, the RNA needs to be converted into DNA by using a process called as reverse transcription. Then, the process of duplicating the DNA is carried out.
Once copies are created, a fluorescent DNA binding dye, called as probe, shows whether the virus is present or not. The test distinguishes SARS-COV-2, which causes the COVID-19, from other viruses.
Is the PCR process lengthy?
According to the IE report, ICMR scientist Dr RR Gangakhedkar said, “The time taken to test samples has been brought down to 4.5 hours from the earlier 6 hours, by the real-time PCR testing. But, the overall time, from taking the sample to delivering the medial report, takes about 24 hours, which is more than it should be.
How is the PCR test conducted in India?
In India, coronavirus testing is conducted in two stages, as the report quoted NIMHANS Head of Neurovirology Dr V Ravi. In the 1st stage, the genetic elements common to the presence of coronavirus are tested. In the second stage, tests specific to the presence of SARS-COV-2 are conducted.
Though, till the beginning of March, the National Institute of Virology in Pune was conducting the second test. But, the facility has now been transferred to all the labs for quicker results, said Dr Ravi.
It is to be noted that India currently has the capacity to check 10,000 samples a day. It is testing around 600-700 samples daily. South Korea too has a similar turnaround time, & has been testing a maximum of 20,000 samples a day.