New Delhi: India’s Covid-19 R value — a measure of how fast the infection is spreading — has reduced slightly to 0.91, compared to 0.92 last week.
However, Karnataka’s R value has once again risen above 1. The R value for the state is 1.08 this week, as opposed to 0.93 last week.
The R value or effective reproduction number needs to be kept below 1 for a period of time for an epidemic to come to an end.
Sitabhra Sinha, a researcher at the Institute of Mathematical Sciences in Chennai, calculated this week’s R value for India, as well as the top 15 states in terms of their current active cases.
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States with rising R value
While most states have managed to keep their R values below 1, some of them are witnessing a rising trend.
Kerala’s R value, for example, increased to 0.94 this week from 0.91 last week. The week before that, the state’s R value was 0.94.
Uttar Pradesh’s R value had reduced to 0.91 last week, from 1.08 the week before. But the value increased this week to 0.94. Chhattisgarh’s R value increased to just over 1, from 0.85 last week.
Himachal Pradesh also saw a rise in its R value, from 0.92 last week to nearly 1 this week. The state’s R value has remained over 1 since 31 October, leading to an increase in its active case load.
States where R value has declined
After Maharashtra’s R value increased to 1.08 last week, the state saw a decline to 0.88 this week. Delhi’s R value has also declined slightly, from 0.78 last week to 0.77 this week.
Last week, Rajasthan’s R value had gone down to 0.95, from 1.22 the week before. It further reduced to 0.80 this week.
Madhya Pradesh and Haryana had R values at 0.94 and 0.84 respectively last week, which has reduced to 0.91 and 0.70 respectively.
Punjab and Gujarat both had high R values last week — 1.12 and 1.08 respectively. Both states saw a decline in their R values to about 1 (Punjab) and 0.99 (Gujarat).
Tamil Nadu’s R value declined from 0.98 last week to 0.97 this week, while Telangana’s R value reduced from 0.84 last week to 0.81 this week.
Major cities
Bengaluru is currently the only metro city with a R value over 1. The R value increased from 0.95 last week to 1.07 this week.
All other major cities have R values under 1. Both Mumbai and Pune managed to bring down their R values from over 1 last week to 0.87 and 0.60 respectively, this week.
The R values for Chennai and Kolkata are 0.88 and 0.91 respectively.
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