In the fight against COVID-19, the need for some degree of social distancing is now apparent worldwide. Findings published in the ‘Lancet Infectious Diseases’ journal conclude that a combination of three physical distancing interventions is most effective. This three-pronged approach involves quarantine for infected individuals and their families, school closures and workplace distancing. The study explored the efficiency of using these three methods, both together and individually, in dealing with the early stages of a COVID-19 outbreak.
Combined physical distancing works best
Based on a computer model of a simulated Singaporean population, the study is the first of its kind to examine the application of these three options for early intervention. In comparison with other intervention studies, the researchers found these to be the most effective at decreasing the number of COVID-19 cases. The next best combination was quarantine and workplace measures, followed by quarantine and school closure. The least effective strategy was quarantine only. The research team devised an influenza epidemic simulation model that considered demographics, individual movement and social contact rates in workplaces, schools and homes. The model estimated the likelihood of human-to-human spread of SARS-CoV-2 if containment efforts fail. Using this model, the scientists estimated the cumulative number of SARS-CoV-2 infections at 80 days, after detection of 100 cases of community transmission. The researchers discovered that a combination of physical distancing interventions reduced the number of infections by between 78 and 99 %.
Lead author Alex R Cook, vice dean for biostatistics and modelling at the National University of Singapore’s Saw Swee Hock School of Public Health, said: “Should local containment measures, such as preventing disease spread through contact tracing efforts and, more recently, not permitting short-term visitors, be unsuccessful, the results of this study provide policy makers in Singapore and other countries with evidence to begin the implementation of enhanced outbreak control measures that could mitigate or reduce local transmission rates if deployed effectively and in a timely manner.” “If the preventive effect of these interventions reduces considerably due to higher asymptomatic proportions, more pressure will be placed on the quarantining and treatment of infected individuals, which could become unfeasible when the number of infected individuals exceeds the capacity of health-care facilities,” Prof. Cook added. “At higher asymptomatic rates, public education and case management become increasingly important, with a need to develop vaccines and existing drug therapies.” The authors cautioned about the limitations of the study, including older census population data, effect of migrant movement, influence of transmission from beyond Singapore and contact patterns between people.
COVID-19, physical distancing, coronavirus, health