New Delhi: For the first time since the coronavirus pandemic broke out, India’s R value — a key parameter to measure the rate of the spread of an infection — has dipped below 1, reducing to 0.93 from 1.08 last week.
According to Sitabhra Sinha, a researcher at the Institute of Mathematical Sciences in Chennai, some of the worst-affected states — including Maharashtra, Uttar Pradesh and Karnataka — have also registered an R value of less than 1.
R value represents the number of people one patient can infect. Epidemiologists have been waiting for the number to drop below 1 in India because this means that the number of recoveries now outnumber the new infections.
“We will still see new infections happening, but the important point is that recoveries are more. If the R value can be maintained below 1, the epidemic will eventually die out but we need to have R less than 1 for a considerable length of time for this to happen,” Sinha told ThePrint.
“Earlier we had seen that in Delhi, after keeping R less than 1 for more than a month, the R suddenly increased beyond 1, thereby losing the gains they had made,” he said.
As of Thursday, India has recorded a total of 57,32,518 cases of Covid-19. The death toll climbed to 91,149 with 1,129 people succumbing to the disease in the last 24 hours.
Also read: Just how much coronavirus we encounter & viral load could be key to recovery, studies show
High-burden states’ R value less than 1
The top five states with the highest number of active cases in India have all registered R values below 1. Sinha said this was the reason for the drop in India’s overall R.
Throughout the course of the pandemic, India’s R value trends have been similar to that of Maharashtra. This week, the state’s R value decreased to 0.86 from 1.17 last week. It currently has the highest number of active cases — 2,73,883 patients as of Thursday.
Karnataka, which has 94,671 active cases, has the second-highest disease burden in the country as of Thursday. The R value for the state reduced from 1.13 last week to 0.91 this week.
Andhra Pradesh has been maintaining its R value below 1 for the last three weeks. Last week, the R value was about 0.95, which has further reduced to 0.80 this week.
Similarly, Tamil Nadu has also kept its R value below 1 for at least three weeks. However, the value rose to 0.99 this week from 0.93.
Uttar Pradesh, which is also among the top five states with the highest number of active cases, has seen a decline in R value from 1.10 last week to 0.91 this week.
Odisha and Punjab also witnessed a decline in their R this week. For Odisha, the R value reduced from 1.11 last week to 1.04 this week. In Punjab, the value declined from 1.16 to 1.07 this week.
R value in metros
The R value trends for all major metros are also encouraging.
While Delhi’s R value was 1.26 last week, Sinha said the value is hovering just over 1 this week. Chennai and Kolkata also have R values very close to 1. The values were 0.9 and 1.03 respectively, last week.
Mumbai, Pune and Bengaluru all reported R values below 1 this week. Last week, Mumbai’s R value was about 1.09, which has declined to 0.67 this week.
Pune, meanwhile, went down from 1.14 last week to 0.56 this week. Bengaluru’s R value reduced from 1.09 to 0.93 this week.
However, some states are still showing an upward trend.
Kerala, which was seen as a model state in handling the disease spread earlier, now has an R value of 1.20. Last week the value was about 1.07.
Assam, where the R value was close to 1 last week, also witnessed an upward trend with it increasing slightly to 1.04.
Telangana has been maintaining its R value below 1 for two weeks now, but the value went up to 0.94 this week from 0.92.
Also read: Bharat Biotech partners with Washington University for Covid intranasal vaccine