Dr Ramanan Laxminarayan, Director of the US-based Center for Disease Dynamics, Economics and Policy, says India should focus on more pool testing to identify clusters in order to contain the spread of the Coronavirus. In an interview with Outlook’s Preetha Nair, Dr Laxminarayan also says that by looking at the pattern of Maharashtra and Tamil Nadu, it appears India is likely to see a peak in Covid-19 cases in early July. Excerpts from the interview:
We have entered lockdown 4.0. How is the situation going to unfold?
An honest answer is we don’t know. In the absence of a lockdown, we are able to model how the virus multiplies. With the lockdown, we don’t know the trajectory of the virus because there is not one Indian epidemic. There is a Maharashtra epidemic, Gujarat epidemic; there is a Tamil Nadu and Delhi one... Epidemic has not even started in states like Jharkhand, UP, Bihar and Chhattisgarh, at least based on the data that is being reported. If you look at the data coming from Maharashtra and Tamil Nadu, it is consistent with a peaking in early July. It seems to suggest that there will probably be a peak in early July going by the shape of the curve. But we cannot be sure. The difficulty for us is that because the testing is very low, we are not taking up most of the cases. We are not sure if the picture we are getting from the data is accurate enough, both in terms of cases as well as deaths.
One of the inputs you need in these models to understand how it’s going to move over time is having good and consistent data. Our problem is that we are a very large country and, therefore, even though they scaled up the testing to over one lakh per day, it looks nothing for a country like India.
There is an argument that India doesn’t need to test everyone as the number of positive cases hasn’t risen in proportion to tests.
That’s not actually true. The reason is that the government only releases data on the number of tests conducted, not on the number of patients. Not even on the number of tests. They are only releasing the number of samples tested.
If there are five samples and if all five samples belong to only one patient, very often they are doing double samples for patients before they are discharged. You need to get two negative samples from the patient before they are discharged. You are throwing those samples also into your denominator. So when you have so many people recovering and for every person who has recovered, you have done two samples, which are negative, naturally you are going to have a large number of tests.
The way in which the other countries are doing this is they are conducting tests wide and across the population. Not in this narrow way. And their rates of positive cases are based on people tested.
Should we focus more on the red zone and hot spots? What should be our strategy then?
We should probably be doing pool testing to identify clusters. That's number one. Second, it’s too late to test a person, find a positive case and quarantine them. We can't keep that up because we can't expand from one lakh tests to 1 million tests, I don't think it's within the country's capacity to do that. What we have to do now is that we have to prevent deaths. So anyone above the age of 60, who has symptoms of Covid, should be tested, brought into our Covid facility and given early care so that they don't die. The testing is not going to be your main way of tracking the growth of the epidemic. So tracking the growth of the epidemic will happen mostly through deaths. It will happen through epidemiological modeling. We don't have enough capacity to do that. We have to use our tests to save lives at this point.
So are you saying that we should aggressively test?
Testing should be done more but I'm also saying that number of cases cannot be on the basis of red zone. Are you saying that some other rural area has no cases at all? It’s just that they're not tested enough. At this point I will be very surprised if any district in India does not have cases. Maybe the Northeast. But we have to look further on that. The virus is spreading really fast.
The government says that lockdown cut the chain of transmission because the doubling rate has come down. Do you think we will see resurgence?
The lockdown definitely slowed down the epidemic. But beyond a point, it is not helpful. So I think the first 21 days of lockdown were helpful and maybe another 10 days beyond that. But after that the last 20 days, it didn’t work. It is just postponing an epidemic. We will see resurgence because that is just the nature of the disease. You have to remember that the purpose of the lockdown was not that the epidemic goes away, or the disease dies out. A lockdown was always to buy some time to prepare.
Everybody is asking us to live with the virus. How do we live with a virus?
I think the government can only do so much, but after a point the virus is going to spread as much as it can and wants to. We have to remember that we have to respect the virus because it is going to dictate the timeline. We have only one weapon against the virus, which is social distancing. Because social distancing was not happening voluntarily, we went into lockdown. After lockdown, we have to maintain the distancing at least somehow to some extent.
There has been so much discussion about the second wave. What exactly causes a second wave?
The epidemic is almost like an ocean wave. It depends on how much the wave is. If it’s moving very fast, it becomes a big wave. Then it crashes down. There is a big wave and it crashes down. Now in the same way, if the reproductive number is very high, then the wave of epidemics also becomes very high. That’s why we tried to slow down the transmission, so that the wave will not be very high. If you are able to have a smaller wave, then there will still be a second wave because there are still people who aren’t infected.
It is better for us to have two or three waves rather than one very big wave. We haven’t seen any waves yet, we are in the middle of wave. It’s still gathering momentum. And we are not yet done with the first wave so it is simply too early to tell. Moreover, it would depend on the lockdown and containment strategy going forward.
Why is the virus behaving severely in some states like West Bengal, Maharashtra, or Delhi, which contribute mainly to the infected population?
Some of it depends on the function of time, function of which population is infecting, the density of that population, etc. Many factors work there. Maharashtra, mostly Mumbai, is a very crowded city. If you ask me why there are so many cases of epidemic now in Delhi, Mumbai, Gujarat, Tamil Nadu, Karnataka, I would say it’s because all these places have international airports. So, all the people who came in first from outside the country came into these states. Since there is no international airport in Patna, they are fine. So where the viruses come from is where the epidemic is now at this stage in time. So these states have epidemics which are running ahead of the other states. You can't compare one state with another. Every state has its own curve and epidemic. And I think they're all doing their best. And you will see the same wave happening in Madhya Pradesh or Rajasthan after some time. Or some other places after this. It's just a matter of time.
Does India have a milder epidemic? Is the virus behaving differently here?
There is no difference in immunity. I think the only difference is that we got the epidemic later. So Pakistan, India, Bangladesh all got it later. Remember, at one point in the global curve of number of cases, we were number 39. Today we have surpassed China in the number of cases. So there is no question of us being more immune. It is just how countries managed to come out of their lockdown. There is no escaping the virus. Nobody is safe from the virus.
Will hot weather bring some respite or more challenges with the onset of monsoon?
Hot weather won’t bring any respite from the spread of virus. Tamil Nadu has lot of cases. All across India, hot weather states have more cases now. There is really no evidence about temperature. And again with monsoon, we are going to see other diseases.
