New Delhi: Amid rising Coronavirus cases in Delhi, many scientists have stated that community transmission of the disease may have started a while ago in the national capital. They have also affirmed that it is possible for Delhi to have 5.5 lakh cases by July end, citing mathematical models of the progression of COVID-19. Also Read - Coronavirus in Maharashtra: Total COVID Cases Cross 2.25 Lakh-mark, 219 Fresh Deaths

“The model that I used for India found that there could be around 8-10 lakh cases in India by mid or end of July. So it won’t be surprising to get to those figures (5.5 lakh) in Delhi,” said Samit Bhattacharya, mathematics professor and researcher at the School of Natural Sciences at Shiv Nadar University. Delhi Deputy Chief Minister Manish Sisodia had on Tuesday said the number of Covid-19 cases could surge to 5.5 lakh by July 31. Also Read - Did You Know? Self-Isolation May Increase Susceptibility to COVID-19

“Delhi getting around 5.5 lakh cases by end July might be possible as the number of cases is growing,” Bhattacharya said. Also Read - Mohammed Shami Reveals Why he Will Have An Advantage Once BCCI Starts Camp

According to virologist Upasana Ray, only epidemiologists and statisticians can comment on exact numbers and predictions. “I believe that if the government is telling something, there must be some basis to it,” Ray, senior scientist at CSIR-IICB, Kolkata, added.

Reaching the alarmingly high figure of 5.5 lakh is possible using mathematical modelling, agreed Lovi Raj Gupta, executive dean of Science and Technology, Lovely Professional University (LPU) in Punjab.

“The validity and the accuracy would depend on the selection of the model based on the variation of data. As this is time-series data, trends and seasonality play vital role,” Gupta said.

Sisodia had, asserted, that there is no community transmission of COVID-19 Delhi. However, Delhi Health Minister Satyendar Jain added in a separate conversation with the media that the source of infection is “not known” in nearly half the fresh cases being reported.

Bhattacharya said community transmission “definitely” started a long time back in Delhi.

“It doesn’t mean the whole of Delhi will have infections uniformly for community transmission to happen. Nearly 30,000 infections in Delhi have already happened and according to the Delhi population it is definitely community transmission,” he said.

“As far as my understanding of disease transmission, in local transmission there is a small spike in the number of infections. After that it gradually increases, and definitely at that point starts the community transmission,” Bhattacharya added.

Ray explained that community transmission is said to happen or is a stage of disease transmission which by definition lacks exact source of transmission for many reported cases, that is the source of infection might not be traced back.

“We have seen a very long and stringent lockdown in our country. Yet, the number of cases have been seen to be rising. In many cases we can’t trace back the source.”

“If the rise in Covid-19 cases can’t be linked to community transmission, then the next question should be…..what is the reason for such an increase? Is the virus more virulent? We don’t know that either. Are we bringing in infection from elsewhere? How can that be? It was a lockdown.”

While all these assumptions are true, it will not be wrong to say that just an increase in infection numbers won’t point to community transmission, Ray added.

(With agency inputs)