New Delhi, After the Tablighi Jamaat incident, the number of the coronavirus positive cases is doubling and it could spiral up in the coming week, but there is no need to panic, said Dr S.K. Sarin, an eminent Delhi-based gastroenterologist at Institute of Liver and Biliary Sciences (ILBS).

Dr Sarin also heads the five-member committee constituted by Delhi government to tackle the COVID-19 crisis, insisting on reduced mobility of people after the lockdown is recommended to contain the outbreak. Here's an interview:

Q.IS 21-day period of lockdown is enough to contain the outbreak of coronavirus, or it should be increased?
The way we are doubling up (on the coronavirus positive cases in the country). We may spiral up in the coming week. After the end of this lockdown period, I suggest we should go for modest lockdown. Mobility should be reduced for at least four weeks after the 21-day period ends. People should wear masks while going out.

* What is your take on the Tablighi Jamaat incident, 30 per cent cases of the coronavirus positive cases are from this congregation?
There is no doubt, it was Delhi's misfortune this congregation took place. It was a hotspot of coronavirus infection. People from this congregation travelled to all over the country. We need to do rigorous contact screening, including those people who have come in contact with people who participated in this congregation. Track their GPS, CCTV images or bank account, whatever is possible.

* What is your reaction on news going around that TB vaccination administered early in childhood could become a silver bullet in fighting COVID-19. Also, the increase in temperature would have an impact on the virus?
There is nothing scientific to establish the TB vaccination claim. As it was administered in childhood, and if somebody goes for it now would it help in fighting coronavirus, there is nothing to show. Moreover, the impact of high temperature on the virus is also not known. There are no good studies on the temperature effect on the virus.

* Have you observed any changes in virus incubation period, and if coronavirus can travel up to 8 meters from exhalation, what do you suggest?
Initially, the incubation period was 4 to 14 days, but now we could see the incubation period has changed from 4 to 24 days. Viral shedding could be low in the initial few days of illness, but it could rise significantly after a few days. Also, the virus can go up to 8 meters. Therefore it is extremely important to wear a mask when you step out of the house. India is among the late spreaders, but there is no need to worry or panic. At ILBS, we are conducting 150-200 tests everyday, which is a good number for a virology lab.

* We are already half-way through the lockdown period and Indian Council of Medical Research is less than 30% of its testing capacity. Should ICMR not increase its testing capacity or roll out widespread testing?
Blood testing has brought a sea change, as it has superseded testing done through nasal and throat swab, which has only 60% accuracy. Initially, it was a nasal and throat swab test, but now we are doing more blood tests. The blood test can be done through kits, which are easily available – and within three days results are available, one could know if he/she has an acute exposure, whereas in nasal and throat swab test positive cases could come out negative. An antibody test, a key part of the response to the COVID-19 pandemic, is a huge development in testing. Currently, we are 10,000 tests every day, but in the middle of next I am hopeful, 20,000 tests per day would be crossed.

* The age profile of the coronavirus positive cases suggest nearly 84 percent are below 60 years; and 75 percent between 21 to 60 years. Do you think it is worrying that more youth and middle age are susceptible to the viral infection?
Majority of our population is young. This does not mean we venture out and do not follow the guidelines on the lockdown and steps to contain the viral infection. Death does not look at age. People above 60 years are more vulnerable and the mortality rate is high, as they have low resistance and other diseases. The outcome of the viral infection is more bad for the elderly. Delhi is well prepared to handle COVID-19 situation.