I am not a medicine guy. I just understand a bit of math. Various studies have identified the R-0 of this virus to be around 3. R-0 means, if there is only one infected person in the otherwise healthy population, how many people will the person infect on an average. So, R-0 of 3 means, if on day 1 you have 1 infection, on day 2 you will have 3, on day 3 you will have 9, then 27, then 81… In a week you have 1000 infections, in 2 weeks 1 million and in 3 weeks 1 billion!
Of course, infection growth will not be that high because as the number of infected people grow, the already infected will find less number of healthy people to infect and there should be some tapering of the curve. At present, in most countries of the world, India being no exception unlike what we were patting ourselves for earlier, the number of cases is doubling every 3-4 days.
By yesterday night, 23 march, there were 500 cases in India. At this rate, India would have reached 2700 cases by 31 March, 1 lakh cases by 18 April, by 30 April the number of cases would be 15 lakhs, 1 crore would have been hit on 10 May. About 5% of cases worldwide belong “serious or critical” category as per worldometer which I am sure will definitely need serious medical care. 5% of 1 crore is 5 lakhs. Assuming an average stay in hospital for 9 days and 3 days rate for doubling the number of cases, 87.5% of 5 lakhs i.e. 4.37 lakh patients would have required intensive medical care on 10th of May. India has just 40,000 ventilators. Of course, as I mentioned, the number of infected grows, any infected person will have lesser number of healthy to infect, so growth rate might slow, but even if we make it 10 June instead of 10 May to 1 crore, the overall picture remains the same. And at this point, I leave the rest to your imagination.
With no medicine/vaccine in sight, the only way to respond to this is freeze people right where they are at least 2 meters away from each other! Or in real world, at least a total lockdown. This virus with an incubation period of upto 14 days means that it is possible with a non-trivial possibility that any person infected today may not show any symptoms for upto 2 weeks from now. Right now we don’t know who all may be infected… may be you, may be me… So what do we do? Impose a total lockdown of 14 days, see who all are showing symptoms during this window, test them and if they are positive admit them. It is sort of a pause button you hit on the world and after 14 days hit refresh. Because if say, even 1 infected person remains, then the vicious cycle will start again… 1 –> 3 –> 9 –> 27 –> 81 and so on…
Again in practicality, a lockdown has to be much more than 14 days. Because even the 14 day incubation period will be based on studies with some sample size and even if there are 0.01% outliers i.e. 0.01% people in the sample who show symptoms after 14 days, in a population of 130 crore or 1.3 billion, it still means 1.3 lakh infections. This, and for other reasons, the lockdown needs to be at least for a month. China is only relaxing after 2 months.
Also the lockdown needs to be near total barring absolute essentials… Like in china and some other east asian countries, they mandated that only one person from each household could come out of the house in every 2 days. After the lockdowns, their virus R-0 dropped to 1.05 from 3 and now they seem to have contained the spread. We can’t have the traditional curfew relaxations in this case where say between 5-7 pm everyone can venture out to purchase essentials, that would defeat the very purpose of a lockdown as it would again aggregate people during those hours! This is not a communal riot curfew we are talking about. We need to figure out a way to keep people separated even in the relaxations to lockdown.
More on lockdown implementation later, but we should realise, as of now lockdown is the only way!
(WRITTEN BY Gaurav Agarwal, IAS, IIT & IIM Graduate, currently posted as Commissioner, Ajmer Development Authority)