Non-pharmaceutical interventions such as voluntary shelter-in-place, quarantines, and other steps taken to control the novel coronavirus can reduce the peak number of infections, daily infection rates, and overall deaths, say researchers, "High compliance with voluntary quarantine - where the entire household stays home if there is a person with symptoms or risk of exposure in the household - has a significant impact on reducing the spread," said study author Pinar Keskinocak from Georgia Institute of Technology in the US.
Utilizing data from the state of Georgia, the study, published in the journal PLOS ONE determined that a combination of non-pharmaceutical interventions could in some instances cut cumulative infections in half and reduce the peak number of infections.
The study compared actual statistics to revised models of what could have happened in the state during the past seven and a half months without the physical distancing.
The study modelled the number of Covid-19 infections and resulting in severe outcomes, and the need for hospital capacity under social distancing, particularly, school closures, shelter-in-place, and voluntary quarantine.
The team developed and used an agent-based simulation model to project the infection spread.
"This is a sophisticated mathematical model which mimics what might happen in practice - under different scenarios - by capturing the progression of the disease in an individual, as well as the interactions between people in the household, in peer groups such as schools or workplaces, or in community groups such as grocery stores," the authors said.
The model utilizes parameters specific to Covid-19 and data from Georgia on population interactions and demographics.
Outcomes were compared at the state and community level for the number and percentage of cumulative and daily new symptomatic and asymptomatic infections, hospitalizations, and deaths; Covid-19-related demand for hospital beds, ICU beds, and ventilators.
The results suggest that shelter-in-place followed by voluntary quarantine reduced peak infections to less than a third of what we would have seen if no intervention had taken place and to less than a half if only schools had been closed.
According to the study, increasing shelter-in-place duration from four to five weeks yielded between two per cent to nine per cent and three per cent to 11 per cent decrease in cumulative infection and deaths, respectively.
"The takeaway message is that each of us has the power to control our health by making the right," the authors wrote.