'1K +ve cases a mark of community transmission having started'
New Delhi: As India's total number of COVID-19 cases crossed the 1,000-mark on Sunday evening, a research paper written by senior ICMR scientists, a researcher from the Translational Global Health Policy Research Cell and a scientist from the Imperial College in the UK has shown that this threshold represents a level at which it is clear that community transmission has been established in India.
The paper, authored sometime in February this year, puts forward a stochastic model to predict how many days it will take for India to hit this threshold and recommends necessary public policy steps to delay the arrival of it. However, the Health Ministry has maintained that India is yet to enter the stage of community transmission.
The research paper examines what percentage of symptomatic and asymptomatic passengers would have to be screened at the port-of-entry to delay the stage of community transmission by as many days as possible. The authors said, "This threshold, although arbitrary, represents a level at which it is clear that transmission has been established in India."
Dr Balram Bhargava, Director-General of ICMR is yet to respond to Millennium Post's question about whether it can now be said that community transmission has been established in India.
According to the paper, which was published in the Indian Journal of Medical Research, these models consider the daily arrivals from China and predict how many days it will take for India to hit the 1,000-mark, by accounting for the connectivity between Delhi, Mumbai, Kolkata and Bengaluru. However, the paper also cautions that its models are based on numbers and data available to the scientists at the time.
It also uses the number of daily arrivals from China based on data between October 2018-March 2019, which is likely to have changed since travel restrictions were imposed by the Centre this year. The paper also looks at what level of airport-screening would delay the 1,000-mark and by how many days. These models also do not account for arrivals from other countries where COVID-19 has spread rapidly and at astonishing rates.
With these limitations, the paper predicted that with 100 per cent screening of symptomatic passengers (which it said was not possible) and 90 per cent screening of asymptomatic passengers, the 1,000-threshold could be delayed to 140 days starting from the first case. But this is only if both symptomatic and asymptomatic passengers are screened, diagnosed and isolated at the port-of-entry.
And while the ICMR has said that it is continuing to test random samples of people with sever respiratory symptoms for COVID-19 to check for community transmission, as of March 19, it had tested a total of 826 such samples, all of which came back negative for SARS-CoV-2 and had thus said "so far there is not enough evidence to point to community transmission".
In the 10 days between March 20 and March 29, India has seen an increase of 800 new COVID-19 cases. In comparison, India's first confirmed case was reported on January 30 and till March 20, the total positive cases stood at 206.