COVID Ebbing As R-Value Drops To Below 1: Study

After breaching the value of one in the first week of August, the R number, which reflects how rapidly the coronavirus pandemic is spreading, has been steadily ebbing, according to researchers at the Institute of Mathematical Sciences, Chennai.

India’s R has fallen to around 0.9, Sitbara Sinha, who is leading the research, told PTI, citing their data.

If R is lesser than one, it means the number of newly infected people is lower than the number of infected people in the preceding period and the disease incidence is going down.

The R-value of Kerala, which has the highest number of active cases in the country, is now below one, signalling a relief to authorities who have been struggling to bring down the infection levels in the state.

The northeastern states seem to have finally come out of the second wave, Sinha said.

The R-value between August 14-16, calculated by the researchers, now stands at 0.89.

The R-value for Maharashtra, another state which has a high number of cases, is 0.89, the data shows.

However, Himachal Pradesh continues to have an R-value of above one, although it reduced in the last few days, while Tamil Nadu and Uttarakhand still have R very close to 1, Sinha said.

Among the major cities, the R-value of Mumbai was lowest (0.70 from August 10-13), followed by Delhi (0.85 from July 31 to August 4), Bengaluru (0.94 from August 15-17), Chennai (0.97 from August 15-17). However, the R value remains high for Kolkata (1.08 from August 11-15) and Pune (1.05 from August 10-14).

The Reproduction number or R refers to how many people an infected person infects, on average. In other words, it tells how ‘efficiently’ a virus is spreading.

A smaller R indicates the disease is on a decline. Conversely, if R is greater than 1, the number of infected people is increasing in each round – technically, this is what is called the epidemic phase.

After the devastating second wave that saw hospitals and health infrastructure being overwhelmed by the patients infected by SARS-CoV2 coronavirus, the R-value started to decline.

During the March-May period, thousands of people died due to the infection while lakhs were infected.

In its bulletin on Wednesday, the Ministry of Health said India saw a single-day rise of 25,166 new COVID-19 cases, the lowest in 154 days, taking the tally to 3,22,50,679.

The national recovery rate was recorded at 97.51 percent, the highest since March 2020. Less than 50,000 daily cases have been reported for 52 consecutive days.

During the May 15-June 26 period, the R value stood at 0.78. However, it slowly started increasing – it was 0.88 from June 20-July 7, 0.95 from July 3-22, 0.96 from July 24-27.

It breached the value of 1.03 for the first time after the second wave during July 27-31. However, since then it has slowly started to decline.

The value was 0.92 from August 6-9, rose to 0.99 between August 12-14. But it slipped to 0.89 between August 14-17.

Earlier this month, the central government said 37 districts across nine states, including Kerala (11 districts) and Tamil Nadu (seven districts) are still showing a rising trend in the average daily new COVID-19 cases over the previous two weeks, even as the nationwide daily new infections continued to register a decline.

It said the R-value is more than one in five states—Himachal Pradesh, Punjab, Gujarat, Madhya Pradesh and Uttar Pradesh, which remains a cause of concern.