New Delhi: The Covid-19 figures may seem to be declining in most states, but the estimates of the R value, which is a measure of the transmission rate of the disease, have gone up in most major states, except Tamil Nadu, Andhra Pradesh and Uttar Pradesh.
Nationally, the R-value, which measures how many people one infected person is likely to transmit the disease to, has gone up from 0.90 last week to 1.04 this week.
An R value of over one means that one person is currently spreading the disease to more than one people and the pandemic is increasing in size.
For Delhi, which is now in the throes of a third Covid wave, the value has gone up from 0.86 to 0.89, but Maharashtra, which has been worst-hit by the disease and was showing a gradual decrease in numbers, has now shown a far bigger increase. The R value in the state has increased from 0.91 to 1.06 this week.
“There has been a setback this last week in the epidemiological situation all around. For the first time, after mid-September, the R for India has increased to greater than 1 from 23 November onwards, though it is still too early to say if this is a sustained trend. We will have to wait for a few more days to see if the trend continues,” said Sitabhra Sinha, a researcher at the Institute of Mathematical Sciences in Chennai, who has been tracking the R value in India since the beginning of the pandemic.
Sinha, however, said it’s too early to call this the beginning of the “second wave”.
“As has always been the case, I think this crossing back of R to values greater than 1 has been triggered by Maharashtra, the state having the largest number of active cases, also having its R value becoming greater than 1 (starting 20 November). Maharashtra has been driving the R overall for India, so this is not a surprise,” he added.
The R value is an important metric in measuring the rate of transmission of a disease even though as a pandemic progresses, other metrics such as testing frequency and positivity rate also become more important.
Also read: India’s Covid R value steady at 0.88, but many states see rise in infection rates
R values of cities
Among other states, the R value for Kerala has gone up from 0.87 to 0.94.
The top three states currently in terms of active cases are Maharashtra, Kerala and Delhi. The fourth state in this list, Rajasthan, has also shown an increase in the R value — from 1.09 to 1.22.
Mumbai, which in many ways has been the epicentre of the pandemic in India, has shown a spike in the R value — from 0.80 to 1.12.
Pune has gone up from 1.02 to 1.08, while Chennai is up from 0.85 to 0.92. Tamil Nadu, however, is showing an overall dip in the R value — from 0.98 to 0.81.
Among the big cities, the only exception is Bengaluru that has shown a slight dip in the R value — from 1.03 to 1.02. The R value has reduced in Uttar Pradesh — from 1.10 to 1.08 — and in Andhra Pradesh, from 0.96 to 0.80.
Also read: India’s Covid R value dips to 0.88, Delhi continues to see above 1