New Delhi: India’s R value — a key parameter to measure the rate of the spread of infection — remains below 1 this week as well, however, the value has increased slightly to 0.97 from 0.93.
This is because several high-burden states and metros saw an upward tick in cases in the past week.
Last week, the R value had dropped below 1 for the first time since the coronavirus pandemic broke out.
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 active cases is going down.
According to Sitabhra Sinha, a researcher at the Institute of Mathematical Sciences in Chennai, R for India has been below 1 for the last 11 days but there were fluctuations in the value.
“It came pretty close to 1 during 22-25 September, but fortunately did not cross back to more than 1 and went down a bit subsequently,” Sinha told ThePrint.
This could be partly because Maharashtra — the state with the highest number of active cases — had R very close to 1 in the same period, Sinha explained.
However, now that Maharashtra’s R value is down to 0.94 again, India’s R value is also down to 0.97, he said.
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Three high burden states have rising R values
“Worryingly, the states having the second and third highest active case numbers — Karnataka and Kerala both have R more than 1,” Sinha said.
Kerala was considered a model state at the beginning of the pandemic for being able to keep infections under control, but now the outbreak in the state has become a cause for concern. Kerala has a total of 61,791 active cases, as of Tuesday.
The R value has been consistently increasing in the state over the last few weeks. Around 23 September, the R value of Kerala was about 1.20, registering a significant spike from 1.07, the week before.
This week the R value has increased to 1.33 — the highest among the worst-affected states.
“Left unchecked the active case load (of Kerala) could become comparable to Maharashtra and thus, the India-wide R can again become more than 1,” Sinha said.
Karnataka, which had an R value of less than 0.91 last week, also saw an upward trend with R increasing to 1.11.
Assam, too, has seen an increase in the value over the last several weeks. Its R value went up to 1.04 around September 23 from around 1 the week before. The R value has now further increased to 1.15.
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Major Metros
While Delhi once again has an R value below 1, all other major metro cities are seeing a rise in their values.
The R value for Bangalore increased to 1.12 this week from 0.95 last week. Kolkata and Chennai both had R values close to 1 last week, but this week the values have risen to 1.08 and 1.13, respectively.
Mumbai and Pune both remained below 1 but their R values have increased. For Mumbai, R jumped to 0.87 this week from 0.67 last week. For Pune, the R value went to 0.95 from 0.56.
Only Delhi, whose R value was slightly above 1 last week, is now at 0.85.
Other high burden states have R below 1
Sinha noted that other states, which have a high number of active cases, have R values either less than or very close to 1.
Andhra Pradesh, for example has R value at 0.87. However, it did register a slight increase from last week’s 0.80.
Uttar Pradesh and Odisha both reported a decrease in R values and are now below 1. The R value for UP reduced to 0.85 this week from 0.91 last week. For Odisha, the R value reduced to 0.95 from 1.04.
Telangana and Tamil Nadu have both maintained their R value below 1 — 0.95 and 0.99 — the same as last week.
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