Coronavirus infections are showing an upward trend in the country again after a steady decline, raising concerns as more states roll back restrictions.
India’s coronavirus R-factor, which indicates the speed at which the infection is spreading, is climbing steadily with Kerala and the northeastern states occupying top spots, according to an analysis by researchers at the Institute of Mathematical Sciences in Chennai.
The reproduction number, or the R-factor as it is known, is the ability of a disease to spread. R is the number of people that an infected person can spread the infection to.
Among major cities, the R-values of Pune and Delhi are moving towards 1, PTI reported, citing the analysis.
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The national capital on July 29 recorded 51 fresh COVID-19 cases with a positivity rate of 0.08 percent. Active cases in Delhi stand at 554. Both the daily rise in cases and active infections have remained more or less the same.
When the number of active cases remains in the range of a few hundreds and the R-value is near 1, then an outbreak can be controlled easily, Sitabhra Sinha of the Institute of Mathematical Sciences, who is leading the team, said.
When the second wave of the COVID-19 infection was at its peak, the country’s overall R-value was estimated to be 1.37 between March 9 and April 21. It declined to 1.18 between April 24 and May 1 and then to 1.1 between April 29 and May 7.
Between May 9 and 11, the R-value was estimated to be around 0.98. It dropped to 0.82 between May 14 and May 30 and further to 0.78 from May 15 to June 26. The R-value, however, rose to 0.88 from June 20 to July 7 and then to 0.95 from July 3-22.
"India's overall active cases are fluctuating too much to get a reliable estimate, but data is pointing at a value close to one. It may tip over either way in the coming few days," Sinha told PTI.
An R-value of 0.95 means that every 100 infected people on an average pass on the infection to 95 other individuals.
If the R-value is lower than one, it means the number of newly infected people is lower than the number of infected people in the preceding period, which means the infections are going down.
The smaller the value of R, the faster the disease is on the decline. Conversely, if R is greater than one, then the number of infected people is increasing in each round -- technically this is called the epidemic phase.
Kerala has the highest number of active cases and continues to have an R-value around 1.11.
"Looks like it will remain in the top spot for the next couple of weeks. The Northeast continues to have a very bad situation with most states having R-value more than one," Sinha said.
The Union Health Ministry on July 29 said it will depute a six-member team to Kerala for effective COVID-19 management as the southern state continues to report the highest daily cases in the country.
Kerala on July 28 recorded 22,056 fresh COVID-19 cases, pushing the infection caseload to 33,27,301, with the number of people who succumbed to the virus rising to 16,457 with 131 more deaths.
In the northeast, only Tripura has an R-value substantially lower than one, while Manipur has gone only marginally below one. Among other states in India, Uttarakhand has an R-value very close to one at the moment.
Among the major cities, the R-value of Delhi was inching towards one. The R-value between June 21- 26 was 0.8. It declined to 0.66 between June 28 and July 6, but rose to 0.84 between July 4 and 20.
Explaining the situation in the national capital, Sinha told PTI if the number of active cases is constant, then the R-value is one.
"Even if R momentarily goes over one, there is a possibility that you can contain it. For example, if the active cases are in hundred, you still have the possibility that you contain it before it goes completely out of hand.
"Once it goes to a few thousand and R is greater than one then the situation is dangerous," Sinha explained.
The R-value of Pune was 0.85 between July 11-13 and 0.89 between July 15-20. For the national capital, the R-value between June 21- 26 was 0.80. It dropped to 0.66 from June 28-July 6, but it rose to 0.84 between July 4-20.
For Bengaluru, the R-value from July 7-13 was 0.92. It increased marginally to 0.95 from July 13-17. It dropped to 0.72 from July 17-23.
In the case of Mumbai, the R-value was 0.96 between July 2 and 4. It dropped to 0.89 for the July 6-9 period. It further declined to 0.74 between July 22 and 24.
For Chennai, the R-value between June 29 to July 7 was 0.63. It shot up to 1.05 during July 16-19 and slipped to 0.94 between July 21 and 24.
In the case of Kolkata, the R-value was 0.80 between July 1 and13, 0.91 between July 12 and 17 and then dropped to 0.86 between July 17 and 24.(With inputs from PTI)