Dr N Devadasan is a public health professional with more than 30 years of experience both at the grassroots level as well as in research and teaching. He has worked with the World Health Organisation as its national programme officer for communicable diseases in India. He has contributed significantly to the design of the health ministry’s Integrated Disease Surveillance Programme. He has also investigated various outbreaks, including three Nipah outbreaks in Bangladesh and India. He is currently the technical advisor to Health Systems Transformation Platform, a non-profit organisation.
In this piece, Devadasan examines the available data for India’s coronavirus outbreak and argues that the country may have overreacted. He addresses four common questions in light of the available evidence.
1. Will the coronavirus infect millions in India?
In Wuhan in China and Italy, tens of thousands are affected and thousands have died. While the disease spread at both these centres at alarming rates, other countries and especially India are currently not showing a similar trend.
Until March 3, India had only three confirmed Covid-19 cases – students who had returned to Kerala from Wuhan. In the month since then, Covid-19 cases have cropped up across the country, but the number remains 1,251 as of 4 pm, March 31.
Compare this with other European countries or China, where the number of cases has rapidly crossed the 10,000 mark, as the chart below shows.
Among the 195 countries that have patients with Covid-19, India ranks 41st in terms of the number of confirmed cases. Considering that India is the second-most populous nation in the world and usually during epidemics, larger countries tend to have a higher number of cases, what explains the fact that there are fewer cases in the country?
Standardising the cases by population, the number of cases in India is 500 to 2,000 times lower than other countries, especially the European countries.
2. Are the numbers in India low because of inadequate testing and underreporting?
Many experts have complained that the government has not been testing enough people for Covid-19. However, most textbooks of applied epidemiology will tell you that once the agent of an outbreak or epidemic is established, there is no need to test new symptomatic patients. It is a waste of resources since there is no difference in the treatment provided to a “probable” Covid-19 case and a “confirmed” Covid-19 case.
At this point, we should consider anybody with a fever and cough as a probable Covid-19 patient and ask them to be self quarantined. The patient and their contacts should be monitored closely for any deterioration in clinical conditions (temperature, respiratory rate, fatigue) and if there is a deterioration, then and only then should they be shifted to a hospital where they may be tested for Covid-19 to confirm the diagnosis. This strategy will save beds, health staff time and will also keep 80% of patients out of hospitals.
Therefore, the government is right in limiting the testing to those who may be at risk. The effort should not be to diagnose more cases but to ensure that those who are sick are treated promptly.
A related question arises: if India is indeed underreporting the numbers for Covid-19 and there are thousands of untested patients out there, then why have they not shown up in hospitals already? It is nearly a month since the first case of local transmission was reported. Given the panic, it is unlikely that patients are sitting at home. For more than a week now, because of the lockdown, clinics and health centres have been closed, which makes it more likely that the patients will end up in the hospitals, which are few and easily monitored.
While it is true that most diseases are underreported in India, some states do better at disease surveillance: Maharashtra and Kerala, which are reporting high number of Covid-19 cases, are both relatively well-performing states. It is unlikely that the new cases and deaths will be missed in these two states. If there is a surge in patients with respiratory symptoms in hospitals, it is unlikely to miss the attention of the media. Such information is hard to suppress in a country like India. So where are these untested patients? Maybe they do not exist.
3. Will the epidemic explode uncontrollably in India?
The fear is part of the “spread to millions” discourse. However, comparing countries that confirmed their first Covid-19 cases around March 3, we see two different groups of countries, as visible in the chart below.
European countries (red lines) have an exponential trajectory. In contrast, countries located in North Africa and the Middle East (blue lines), as well as India (the thick green line) have a linear trajectory. This is further highlighted when we compare the most affected countries with India.
The X-axis is the number of days since the onset of the outbreak, and we see once again that India is performing very differently from other countries. The number of Covid-19 cases in India is rising by a factor of 1.45, compared to a factor of 198 in Italy.
We are currently not following an exponential trajectory compared to other countries. This begets the question: will the epidemic play out differently in India compared to European countries?
4. Will the coronavirus kill lakhs in India?
Many have been rattled by the mortality rate often cited in the media: 3%-5%. However, one needs to look closely at this figure. As of March 27, the average case fatality rate in India was 4.5 deaths among 100 patients.
However, the average is not the right measure to use in such a situation since it is affected by extreme values. For example, in Tanzania, out of three Covid-19 patients, one died, so the case fatality rate is 33%. You will see this similar pattern in countries with low incidence of the Covid-19. Their case fatality rate is high and this contributes to the higher average.
On the other hand, the median is not affected by extreme values and gives you the 50th percentile of the case fatality rate. Using the median, the case fatality rate for India drops to 0.4 deaths per 100 patients, nearly ten times. Data from 195 countries shows 95% of the countries will suffer a case fatality rate between 0 and 0.8 deaths per 100 patients.
This case fatality rate further falls if we include the untested asymptomatic patients into the calculation. As I do not have those figures, I hesitate to arrive at any conclusion.
However, it is worth looking at population-based death rates to get some perspective. Hubei province where Wuhan is situated has a population of 5.85 crores, comparable to any of our medium-sized states. This province saw a total number of 3,295 Covid-19 deaths, that is, a death rate of five persons per one lakh population. Without the Covid-19 outbreak, an Indian state with a population of six crore would have seen about 420,000 deaths every year, that is, 1,150 deaths every day because of heart attacks, strokes, road traffic accidents, diarrhoea, pneumonia and cancers. At the current rate of cases in India, Covid-19 related deaths are likely to be less than 1% of this usual number of deaths.
In Italy, the estimated deaths for a similar population size would be 27,000 – nine times more than Wuhan. The point to note is that most of the deaths happened among adults more than 70 years of age. Given that 23% of the Italian population is elderly, it is not surprising that the death rate in Italy is high. On the other hand, India, with only 6.3% of its population above 65 years of age, is unlikely to see this level of mortality.
Indians have been driven into a panic mode because of the deaths reported in Italy and Wuhan. But India is not Italy, it is not China: our genetics, environment and people are very different.
So far, we have not seen an exponential growth in Covid-19 cases as predicted by various experts and simulations, despite our large population, overcrowding, low level of hygiene and the laissez-faire attitude of the public. We can only speculate about the possible reasons:
- Contact tracing and quarantining ensured that the outbreak was largely limited to family contacts and did not spill over to the community.
- The weather in India is not conducive for the virus to spread as rapidly as it did in Wuhan and Europe. Indians have an innate immunity to the virus, thanks to unhygienic conditions.
- This hypothesis can be quickly confirmed by doing serological surveillance among the non-contact populations to see whether they have an antibody to the Sars-CoV2. The Indian Council for Medical Research has already announced plans for such surveillance.
The bottom line is that the data available so far suggests that the novel coronavirus may not infect millions of people in India as predicted by some mathematical simulations. Most patients would possibly only suffer from a cough and fever and recover without any residue. Some will succumb to this virus, but the numbers will most likely not be as high as predicted.
While simulations predict dire situations, we need to keep in mind that simulations are based on assumptions. In contrast, I have drawn conclusions based on the current path of the virus in India based on available data. Let us hope that I am right.
The author would like to thank Pranay Lal, Sunil Nandraj, Rajeev Sadanandan and Tarun Seem for their comments on an earlier version of this article.
These views expressed in the article are personal and do not in any way represent those of the HSTP.
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