India’s R value rises slightly to 0.91, infection rate below 1 in major states & cities

States with high active cases recorded slight increases in their R this week, but are still below 1.

Representational image of the Covid vaccine dry run | Manisha Mondal | ThePrint

New Delhi: The effective reproduction number (R) — an indicator of how fast an infection spreads in a population — for Covid-19 in India has increased slightly to 0.91 from 0.90 last week.

Before this, the R value had remained constant at 0.90 for two weeks. R must be sustained under 1 for an epidemic to come to an end.

Sitabhra Sinha, a researcher at the Institute of Mathematical Sciences in Chennai, calculated the R values for the country and the top states with the highest number of active cases.

“For the states, the situation has improved with Kerala now back to R less than one. In fact all the top 16 states and the major cities currently have R less than one,” Sinha told ThePrint.

For the last two weeks, Kerala’s R value had been over 1 while the state saw a surge of cases. However, this week, the value has dropped to 0.95.

West Bengal, Chhattisgarh, Gujarat and Rajasthan — all states with a high number of active cases — saw their R values go down compared to last week.

For West Bengal, the R went to 0.74 from 0.82 this week. Meanwhile, for Chhattisgarh, the R reduced to 0.79 from 0.80 last week.

Similarly, for Gujarat, the R was 0.93 last week, but reduced to 0.91 this week. Rajasthan’s value dipped to 0.81 from 0.83.

States see slight rise in R value

However, several states with a high number of active cases saw a rise in their R values, which explains the small overall increase in India’s R.

Maharashtra, which has the second-highest burden of active cases, saw R increase to 0.88 this week from 0.86 last week. Karnataka, which has recorded the second-highest number of Covid cases since the beginning of the pandemic, also saw an increase in R value, to 0.85 from 0.82.

Madhya Pradesh’s R rose to 0.91 from 0.90. Delhi, too, saw a rise in R to 0.79 this week from 0.67.

Meanwhile, all major metro cities now have R values below 1. Mumbai, which had recorded an R of 1.10 last week, saw a drop in the value to 0.65 this week. Pune’s R value was close to 1 last week but has now reduced to 0.85.

Kolkata’s R dropped to 0.69 from 0.76, while Bengaluru’s R reduced to 0.70 from 0.81 last week.

Chennai’s R value remained unchanged from last week’s 0.90.