# Why the increase in the number of coronavirus reproductions in some states is causing concern

Since June 20, the effective reproduction number of the SARS-CoV-2 or R virus, which is the number of people an average Covid-19 patient infects, has approached one, from 0.78 to 0.88, based on calculations by __Sitabhra Sinha__, professor of computational biology and theoretical physics at the Institute of Mathematical Sciences in Chennai, show.

This is dangerous because good management of the pandemic requires that fewer and fewer people become infected, because *IndiaSpend* __reported__ in May 2020.

An R less than 1 means that a patient does not even infect one more person, on average, and if the number continues to drop there will be fewer and fewer cases in the future. If each Covid-19 patient infects one more person, the spread remains slow, but many people contract the disease. If R is greater than 1, the infection can get out of hand.

For example, at the current R of 0.88, 10 patients would have infected about nine people. If R was 1, they would have infected 10 more people. The R in Kerala is currently 1.1, which means that 10 patients infect 11 more people.

Since India’s R is still below 1, active cases will decline, but the rate of that decline has slowed, which is “worrying,” Sinha said.

Between May 15 and June 26, new cases of Covid-19 decreased at an average rate of 4% per day while between June 20 and July 7, they decreased at an average rate of 0.5 %, __The data__ of Covid19India.org broadcasts.

When everyone in the population is equally susceptible – that is, when no one has developed immunity to the disease as a result of a previous infection or vaccination – and there is regular contact between people without any quarantine or containment measures, the disease would spread to the basic reproductive level. (R0 or zero), which is the infectivity of the virus itself.

Between March 14 and April 5, 2020, at the start of the pandemic, when almost everyone was susceptible to the virus, each Covid-19 patient would infect 2.5 more patients, Sinha said.

As time passes and some people recover from the infection or get vaccinated and become immune, and measures are taken for containment, such as isolation, masking, and physical distancing, the disease is said to be limited to its natural transmission and researchers are calculating its effective reproduction number, R.

**State level trends**

Even though India’s R is less than 1, several states have R currently greater than 1. “The Northeast is an area of great concern,” Sinha said. Arunachal Pradesh and Tripura have an R greater than 1, while Meghalaya has an R of 0.92, Sikkim of 0.88, and Mizoram of 0.86, shows data for the four states for which the numbers R are available until the first week of July. Manipur’s R between June 27 and June 30 was 1.07.

The R for Covid-19 in Uttarakhand is 0.94. In Odisha and Tamil Nadu, it is 0.90. “The other states have R

These small numbers can make a big difference in the rise of Covid-19 in the state. For example, 100 people in Arunachal Pradesh, with an R of 1.14, would infect 114 other people.

In West Bengal’s R of 0.89, 100 people would infect another 89, reducing the number of active cases over time. Likewise, at Karnataka’s Covid-19 R of 0.56, 100 people are believed to infect another 56, leading to a rapid decrease in cases over time.

*Pragathi Ravi**, intern at **IndiaSpend**, contributed to this article.*

*This article first appeared on IndiaSpend**, a nonprofit data-driven, public interest journalism organization.*