UPDATED: December 24, 2020 | 13:07 IST
The discovery of multiple new strains of highly-infectious Covid-19 virus has spooked citizens even as the government asked them not to panic. Since there is little information about the new strains of the novel coronavirus, it has caused fresh panic. And the recent news about ten passengers from UK testing positive has only added to the fears. Genome sequencing will now determine whether the mutant virus has entered India or not.
Doctors are of the view that people need to be careful and ignore rumours as it may lead to unnecessary anxiety. India Today TV got in touch with Doctor Lancelot Pinto, Consultant Pulmonologist, P.D Hinduja Hospital & MRC, to know more about the various aspects of the mutant strain.
What is genome sequencing?
A genome sequence is a unique way in which an organism’s genetic material is organised. In the case of viruses, this unique RNA sequence is used to create proteins using the host cell’s machinery (in the case of SARS-CoV-2, human cells serve as host cells). Changes in the sequence change viral proteins and these changes can then influence functions of the virus, such as infectivity and virulence (severity of infection caused). Genome sequencing uses techniques to decipher this unique genetic code and this helps differentiate one viral strain from another and consequently the differences in protein created by these differences in viral strains.
How will we know whether the mutant strain has entered India?
Whole-genome sequencing (WGS) is the definitive test that will tell us whether the strain has entered India. This is not routinely done but is part of research and surveillance. Interestingly, one of the PCR tests used (TaqPath) which looks for 3 genes in the viral RNA leads to one of the 3 signals being negative for the mutant strain and this could serve as a clue at the ground level. Labs should report this funding whenever they see it so that such samples can then be confirmed with WGS.
Are young people at bigger risk?
Based on very early signals from the UK, it might be possible that the new strain infects younger individuals more but this is confounded by the fact that this could just be a reflection of social behaviours changing more among the young. Symptoms do not appear to be different, but we might know more as we have more experience with the new strain.
So, what changes?
As of now, nothing changes as far as the management of infected patients (irrespective of the strain). WGS is not widely available, so it might not be easy at an individual level to know the strain that caused the infection. However, the clue on RT-PCR mentioned above (2 of the three genes being positive on a nasopharyngeal swab) might help suggest what the strain could be.
How much have we known about the virus in the last eight months?
We know a lot with respect to how the virus behaves, what the red flags are when treating a patient and how to best optimize treatment. In the treatment of patients with COVID, corticosteroids are given at the right time save lives. Remdesivir has had mixed results in trials, blood thinners may have a role. None of the other drugs that are being widely prescribed has any role, unfortunately. We are employing better ventilator strategies, admitting patients only when absolutely necessary, and not unnecessarily prolonging isolation. However, viruses are known to mutate, either accidentally or purposefully to avoid host defences, and this means that we can expect hurdles, and we have to be prepared to constantly learn and evolve our strategies to outwit the virus.
We need to emphasize in our messaging that nothing has really changed after the reporting of the new strain we still have no reason to believe that it is more virulent and the existing precautions (masking, sanitizing and distancing) should be sufficient, irrespective of the strain.