COVID-19: India hopeful as daily recoveries exceed new infections for 6 consecutive days, R-value falls below 1

Coronavirus in India: India has been witnessing continuous growth in the coronavirus cases. However, over the last few days, there have been promising signs which make the country hopeful of an improvement, even if the hope is temporary. For the sixth consecutive day, on Wednesday, India saw more recoveries than new infections, according to a report by IE citing government data. This is something that did not happen for more than a day before, and they seemed like anomalies in the data, rather than a trend. Now, as a result of the rapid recovery, the number of active cases has started declining, a trend visible in the country for the first time since the pandemic wave struck India in March.

On September 17, the number of active cases in India were on a high of 10.17 lakh, the report said, and this number has now declined to 9.66 lakh.

In case of the spread of an epidemic, it is the active cases that matter, since these are the cases which pose a threat of further transmission of the virus to others. Moreover, it is only the active cases that need to undergo medical care, so a decline in active cases also indicates the reduction of burden on the healthcare sector in India.

The report added that in such cases of epidemic, experts eagerly await a clear trend of recoveries exceeding new infections, since it could be read as a sign for the slowing of the spread. While it is still too early to pin all hopes on it, as such a trend needs to stay constant over a period of several weeks for it to be more meaningful, it still is a positive sign.

Apart from that, the R value or the reproduction number, which indicates the speed of spread of a disease in a population, has now fallen below 1, something that had not yet happened for COVID-19 in India. R-value indicates the average number of people being infected by an already infected person. At an R-value of 1, every infected person transmits the disease to one other person. Thus, a value below 1 means that fewer people are contracting the infection as compared to the number of people currently carrying the disease.

The present R-value of India has been calculated by Sitabhra Sinha-led team of researchers at the Chennai-based Institute of Mathematical Sciences (IMSc) and the value stands at 0.93. This means that every 100 people infected with the disease today are on an average transmitting the disease to only 93 more people.

The falling of R-value below 1 is also an indicator which experts eagerly wait for, since that also indicates that the pandemic is beginning to end.

But, there are some important limitations.

The report stated that R-value is not an absolute metric, with different researchers being able to ascertain varying R-values. This depends on the computer models the researchers are using, and the assumptions that underlie their calculations. However, in a broad sense, the increasing or decreasing trends are usually captured uniformly across all models, the report said, adding that IE had been reporting the R-values calculated by Dr Sinha-led team since March, and this is the first time that their R-value has gone below 1.

The report further added that there were inherent uncertainties while calculating or estimating the R-values during the pandemic.

It added that even the worst affected states are reflecting the national declining trend in R-value. In the top five states as per caseloads, the R-values have fallen below 1, and this is a first for all of these states.

Moreover, these worst-hit states of Maharashtra, Andhra Pradesh, Tamil Nadu, Karnataka and Uttar Pradesh, have also reported more recoveries than new cases on several days over the course of the past two weeks, and the active cases have also fallen in all of these states over the past few days. This decline has been most visibly seen in Andhra Pradesh, with a fall of 10% over the past two weeks.

This indicates that the national trends are closely linked to the ground situation, and are not being swayed by an abnormal trend in one or a few states, as had been seen a few months ago, when Maharashtra accounted for about 40% of India’s caseload. This new trend, however, seems to be evenly spread out over several states, even those outside of the big five.

What is powering such trends is, however, unclear.

The report stated that the most optimistic guess for these trends would be that more than half of the country’s population has already been infected by the virus. However, from serological surveys carried out in several cities, it is clear that that is not the case yet, and only a few places, like Pune, have shown a seroprevalence of over 50%. The infection rate is way less in most cities.

Policy interventions like restrictions and lockdowns could also have resulted in such a trend, since decline in person-to-person interactions can cause the R-value to fall. However, after the government lifted the hard restrictions it had placed back in March and April, no governmental interventions that could have such results have been implemented.

While strict social distancing and usage of masks could be a reason for such a decline in theory, anecdotal evidence from several parts of India show that people are hardly following the physical distancing norms.

Thus, the one probable reason that the report zoned in on, backed by some evidence, was that detection of cases depended on testing. Therefore, if the testing in the country is further enhanced, more positive results would be produced, as there is a high possibility that many more people have been infected by the disease than those being detected by testing.

The report added that over the past one week, the country has seen a slight decline in the testing, with the seven-day moving average of daily tests falling to 9.81 lakh as on Wednesday. This is the lowest for September. This figure was at its highest in the month on September 13, standing at 10.98 lakh tests.

The report quoted IMSc’s Dr Sinha as saying that in the absence of other evidence, it was possible that this slight decline in testing is what has contributed to the fall in R-value, adding that they cannot be sure. It was important, Dr Sinha added, that the trends could change any time and so, it must be ensured that neither the people nor the government lowers their guard anytime soon.

This has already happened in Delhi in August, when the city’s R-value fell below 1 and its reported recoveries were exceeding the reported new infections for over a period of a month. The number of daily infections had declined below 1,000 and active cases once went down to nearly 10,000. However, the city saw a new surge of cases in the past few weeks, causing the number of cases to spike steeply.