Lockdown will help contain Covid-19 only if it is associated with increased testing, tracing and isolation: IIT Bombay study

The models also suggest that the number of cases of infections will soar once the lockdown restrictions are lifted.

Lockdown, as a measure to curb the Covid-19 spread, will help only when it is associated with increased rate of testing, tracing and isolation, finds a multi-model analysis of infectious diseases by researchers from the Indian Institute of Technology (IIT), Bombay. The models also suggest that the number of cases of infections will soar once the lockdown restrictions are lifted.

Indian Institute of Technology, Bombay. (HT file)

“Once the lockdown is lifted, the numbers are bound to increase, according to the models. However, the models also show that lockdown alone will not help curb the infection. We need to test aggressively and isolate those infected, especially since there are many asymptomatic cases,” said professor Subimal Ghosh, from the civil engineering department who was a part of the project.

The finding corroborates the need for increased testing as stated earlier by the World Health Organisation. Similar findings were released on Tuesday by the Indian Scientists’ Response to Covid-19, a voluntary group of more than 400 scientists, who made the first India-specific epidemiological model. They, too, said that extensive testing, quarantining and continued social distancing - not a lockdown alone - are the most effective strategy to contain the pandemic in India.

The analysis released on Wednesday is an IIT-Bombay-Ministry of Human Resource Development initiative in collaboration with IIT Gandhinagar, Indian Council of Medical Research and Visva-Bharati University in West Bengal.

As part of the analysis, the teams used three models for making epidemiological predictions for the number of incidences of the virus for different time periods under different circumstances. While the system dynamics model is a mathematical modelling of complex scenarios, the X-SEAIPR model is a technique to simplify the mathematical modelling of infectious disease and the statistical model makes assumptions to predict scenarios. While the first two models suggest a spike in the number of cases once the lockdown is lifted, the third model suggests a steady increase in the number of infections after lockdown.

Further, a risk analysis of the existing cases shows that some parts of the country are at more risk than others. This means that though the number of cases are low in a state, the population could be more vulnerable based on the social indicators of the place. For instance, Kerala had the highest number of cases at some point of time in the past, but due to better social conditions, the state could achieve the highest control over the number of infections.