Why is COVID19 testing not done for anyone and everyone?
- S. Kaushik
Covid testing_1 &nbs
The Indian Council of Medical Research (ICMR) has revised the guidelines for testing to track COVID-19 cases. According to the new guidelines the following people have to get tested:
- All hospitalised patients with severe acute respiratory illness (having symptoms of shortness of breath, fever and cough)
- Asymptomatic direct and high-risk contacts of an infected person should be tested between the fifth day and 14th day of coming into contact with the patient.
- Symptomatic health care workers
- Symptomatic contacts of those whose laboratory tests (even the preliminary ones at the state-level) have been tested positive for the virus
All asymptomatic individuals (those not having symptoms of COVID-19), who have undertaken international travel in the past 14 days are to stay in home quarantine for the next two weeks and should be tested when they show symptoms.
The focus still remains on finding imported cases and testing their contacts who show symptoms, as there has not been community spread. Earlier the approach was to focus on those who showed symptoms of COVID-19 and had a travel history to any of the COVID-19 active countries, their contacts who show symptoms and symptomatic health-care workers managing patients with severe acute respiratory distress.
The Testing Process
Nasal or throat swabs (site where the virus accumulates) of the patient are taken, frozen and sent to one of the government centres for testing. One sample is sent to the National Institute of Virology, Pune for rechecking. During the testing process, the sample is put in a machine that separates the ribonucleic acid (RNA). RNA is the genetic material that carries genetic information. It is the RNA that is put to test further. An enzyme is added to the RNA which gets converted into a DNA (deoxy ribonucleic acid which is nothing but protein material containing genetic information).
Researches so far conducted have identified the areas on the SARS-CoV-2 genome that contain proteins different from other corona viruses. Primers (small DNA particles) are added that acts like a key and opens the virus’s genome. A fluorescent dye is added that detects the DNA. The probe lights up when the DNA is detected which confirms the presence of COVID-19. This is by far the accurate tests that are conducted and takes a few hours for the testing process to complete.
There are currently 79 laboratories across the country. The testing is done free of cost and it costs the government around ₹4500 per test. The probes and primers are imported and so far the ICMR has ordered a million of them. Conducting tests for anyone and everyone with symptoms (it could just be a normal flu), will result in these resources getting wasted and not to mention the loss of time. This could have implications in identifying and treating genuine COVID-19 cases. God forbid, if community transmission were to happen, these resources would go scarce. A community transmission is a scenario when it is no more possible to trace the contact history of a virus positive case.
Being Positive (not for the virus)
So far, there has been no community transmission as random testing at more than 60 locations for community spread has turned out to be negative.
With Janata Curfew being implemented across the country along with the ban on international flights, stopping of trains across India, sealing of borders of different states and rigorous screening by state and commercial establishments, things are expected to get better. The new guidelines allow for the testing of those at high-risk and allows the government to track better, isolate and provide the necessary for people who test COVID-19 positive.
(The author is Deputy Director, Tamilagam Research Foundation)