Covid 19: India's R-Value below 1, researchers say spread has slowed down

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The R-value, or reproductive number, for COVID-19 in India dropped from 1.17 in August end to 0.92 in mid September, indicating that the spread of the infection across the country has slowed down, according to researchers. However, the R-values of some major cities, Mumbai, Kolkata, Chennai, Bengaluru, are over 1. The R-value of Delhi and Pune are below 1.

The R-values of Maharashtra and Kerala are below 1, giving a much needed relief to these two states with the highest number of active cases. The R-value was 1.17 at the end of August. It declined to 1.11 between September 4-7 and since then it has remained under 1.

"The good news is that India's R has continued to be less than 1, as is that of Kerala and Maharashtra, the two states having the highest number of active cases," said Sitabhra Sinha of the Institute of Mathematical Sciences, Chennai.

Sinha is leading a team of researchers who calculate the R-value.

According to the data, the R-value of Mumbai stands at 1.09, Chennai 1.11, Kolkata 1.04, Bengaluru 1.06.

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.

After the devastating second wave that saw hospitals and health infrastructure being overwhelmed by the patients infected with 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.

When the second wave of the coronavirus was at its peak, overall, the R-value in the country was estimated to be 1.37 between March 9 to April 21. It declined to 1.18 between April 24 to May 1, and it further dropped to 1.10 between April 29 to May 7. Between May 9 to 11, the R-value was estimated to be around 0.98 and then 0.82 between May 14 to May 30. The R-value from May 15 to June 26 was 0.78. However, it increased to 0.88 from June 20 to July 7.

The R-value value between September 4-7 was 0.94, 0.86 between September 11-15 and 0.92 between September 14-19.

According to the Health Ministry, the recovery rate currently stands at 97.75 per cent. The weekly positivity rate (2.08 per cent) has been less than 3 per cent for last 88 days.