New Delhi: India’s effective reproduction number (R) for Covid — an indicator of how fast the infection is spreading — has dropped to below 1 for the first time since February.
According to Sitabhra Sinha, a researcher at the Institute of Mathematical Sciences in Chennai, the value of R fell to 0.98 around 11 May.
“The value is hovering close to one, so if some states with high R end up having much higher number of active cases, it can yet climb back to more than one,” Sinha told ThePrint.
India’s drop in R is primarily because Maharashtra’s lockdown drove its R to below 1.
Karnataka, which has now overtaken Maharashtra in terms of the the number of active cases saw its R decrease to 1.04 from 1.25 last week.
Several of the states with the highest number of active cases now have R below 1.
However, it is important to note that the calculation of R is dependent on the number of active cases being reported from the country.
Maharashtra
Since the beginning of the pandemic, India’s R values have closely mirrored those of Maharashtra — since the state has had the highest burden of cases at most times over the course of the pandemic.
Over the last several weeks, Maharashtra’s R fell to below 1 — which helped bring down the active cases across the country to some extent.
As of this week, the state’s R is at 0.92.
Other states
Meanwhile, Tamil Nadu currently has the highest R of 1.29, increasing from 1.11 last week. This shows that the Covid curve continues to rise in the state.
Similarly, Punjab too saw a rise in the Covid curve, from just over 1 last week to 1.27 this week — the second highest among the states with highest burden of active cases.
All other states with the highest number of active cases saw a drop in their R values.
Delhi, which has seen its active cases decrease, saw the R value fall to 0.68 from nearly 1 last week.
The states of Bihar, Uttar Pradesh, Telangana, Gujarat, Haryana, Madhya Pradesh and Chhattisgarh all reported R values below 1.
However, for Gujarat and Telangana, the number of daily tests conducted has drastically reduced too, indicating that these state may be missing out on cases.
Major cities
Chennai is currently the only city which has R significantly over 1 — at 1.27. All other cities have R below 1.
For Pune, R reduced from last week’s 1.07 to less than 1 this week. Mumbai, which already had R at 0.86 last week saw a further decrease in its R to 0.60 this week.
Both Kolkata and Bengaluru had R at 1.19 last week. For both cities, R is close to 1 this week.
(Edited by Manasa Mohan)