New Delhi: The spread of coronavirus is intensifying domestically and so are the government measures to tackle it. Like, initially, the government and ICMR (Indian Council of Medical Research), the nodal agency for the drive against COVID-19, resorted to testing coronavirus suspects only in designated government hospitals. But, addressing the call for more testing centers, the government has roped in private laboratories and as of March 27, 44 private laboratories have been authorised by ICMR to conduct COVID-19 tests.
While the government has increased the number of testing centers, there are doubts like even in private laboratories, who can be tested? Can anyone go and ask for the test? Is it like a regular blood test? What is the testing procedure? Are private laboratories offering COVID-19 tests for free? Here we will get answers to all and more such questions related to the COVID-19 test – one of the essentials to flatten the curve.
When And Who Can Get Tested For COVID-19?
Following the ICMR guidelines (revised on March 20), individuals who have undertaken international travel in the last 14 days and have symptoms – fever, cough, difficulty in breathing need to be tested. Asymptomatic individuals having a travel history need to home quarantine for 14 days and are tested only if they become symptomatic.
Apart from this, all symptomatic contacts of laboratory-confirmed cases; all symptomatic health care workers; all hospitalised patients with Severe Acute Respiratory Illness (fever and cough and/or shortness of breath) should be tested.
Asymptomatic direct and high-risk contacts of a confirmed case should be tested once between day 5 and day 14 of coming in his/her contact. Direct and high-risk contact include those who live in the same household with a confirmed case and healthcare workers who examined a confirmed case without adequate protection as per the World Health Organisation’s (WHO) recommendations, reads the revised strategy of COVID-19 testing in India.
Explaining who validates whether a person needs to undergo a COVID-19 test or not, Dr Navin Dang, founder and director of Dr Dang’s lab said,
The lab technician going to the patient’s home for sample collection asks for a doctor’s prescription wherever the doctor must have very judiciously selected the patient for the test. A doctor’s prescription is a must.
This clearly means that an individual can’t request for a COVID-19 test or go to any laboratory to get tested only because he/she feels he/she has contracted the virus and wants to be sure of it.
What Are The Different Kinds Of COVID-19 Test?
There are two kinds of the test – RTPCR (Reverse transcription-polymerase chain reaction) and a CT scan of the chest, to detect the presence of the coronavirus in an individual. Explaining how to select the right kind of the test, Dr Rajesh Parikh, Director Medical Research and Neuropsychiatrist at Jaslok Hospital and Research Centre said,
There are two important markers of the value of a test – sensitivity and specificity. Sensitivity is the ability of a test to correctly identify those affected with the disease and not give false negatives. The more sensitive a test is, fewer false negatives will turn up. On the other hand, specificity is to identify those without the disease and not declare false positives. For instance, out of 100 people, 75 have been infected and the test shows, 80 are infected. The test has given five false positives. While RTPCR is more specific than sensitive, CT scan has a high sensitivity rate.
If one has to make a choice between false positive and false negative, one should go for false positive as it’s better to be falsely tested positive and get isolated than wrongly declared negative.
If an individual is tested false negative for COVID-19, he/she will rejoice, move freely and continue to infect others, said Dr Parikh.
Currently, in India, RTPCR is being followed for the diagnosis of COVID-19. Explaining why CT scan is not done, Dr Parikh said,
Through CT scan you get ground glass appearance in the lungs of patients who have an illness such as in a windscreen hit by a stone becoming opaque. The entire process of CT scan including the preparation of the patient and machines takes 30-40 minutes and people will have to line up for the test. While waiting, people can infect each other. Besides it is expensive and can only be performed in few centers.
How Is The COVID-19 Test Done?
The entire process can be divided into various parts ranging from sample collection, screening, preparing the report and transporting the positive samples. Private players have been asked to follow the home collection of samples so that suspected COVID-19 patients do not travel to reach the laboratory and infect others.
Elaborating on the process, Dr Dang said,
The first and foremost step is sample collection. As and when we receive a call for the test, a technician goes from here (lab) in a car. He/she carries Personal Protective Equipments (PPEs) – protective gears designed to safeguard the health of workers by minimising the exposure to a biological agent. On reaching the patient’s house, the technician puts on PPEs, collects the patient’s government identity card, doctor’s prescription and a form stating his/her travel history, symptoms, and other details.
Following this, a sample is collected using different methods like a swab is taken from a patient’s throat and nostril. It is then kept in ‘virus transport medium’ in order to protect and safely transport it to the laboratory. In the laboratory, using the government recommended and approved chemicals – primers and probes, the sample is extracted.
Coronavirus contains RNA or Ribonucleic acid which gets activated during the extraction process. From the time the sample reaches laboratory, it takes about five hours to test it thoroughly and give the final verdict, said Dr Parikh.
In India, two tests – screening and confirmatory test are done back to back before giving the final report. Only doing the screening test gives a certain amount of false positive or false-negative that’s we give a final report after the confirmatory test, said Dr Dang.
The result is validated by the microbiologist and sent to the government in real-time. While the negative samples are kept in the laboratory for three days and then discarded, positive samples are sent to ICMR-NIV, Pune.
What Is The Cost Of A COVID-19 Test?
The national task force for COVID-19 recommends that the cost of sample testing should not exceed Rs. 4,500. This includes two tests – screening test costing Rs. 1,500 and a confirmatory test costing Rs. 3,000.
We are doing this test at a cost price of Rs. 4,500 and provide end to end facilities – from sample collection, sample testing, to delivery of the final report, said Dr Dang.