Physical distancing steps are most effective against coronavirus, study suggests

Research in Lancet Infectious Diseases journal investigates early-intervention measures

A combination of physical distancing interventions – quarantine, school closures and workplace distancing – is most effective at reducing the number of Covid- 19 cases, a study published today suggests.

The research, published in the Lancet Infectious Diseases journal, is the first of its kind to investigate using these options for early intervention. The modelling study was carried out by doctors at the National University of Singapore.

Lead author, Dr Alex R Cook, 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.”

The findings are especially relevant as the Government here introduces tighter controls on activity. It has restricted gatherings to four people and closed non-essential shops. Cafes and restaurants have been told to limit activities to takeaway food only. And existing measures have been extended until April 19th.


Researchers established that, as a baseline, the median number of infections at day 80 of the outbreak was 279,000, corresponding to 7.4 per cent of the resident population of Singapore. They found that, compared with baseline and at different levels of infectivity, a combination of physical distancing interventions reduced the number of infections by between 78 and 99 per cent.

Writing in a linked comment, Joseph A Lewnard and Nathan C Lo of the University of California, said: “Although the scientific basis for these interventions might be robust...political leaders must enact quarantine and social-distancing policies that do not bias against any population group. The legacies of social and economic injustices perpetrated in the name of public health have lasting repercussions.

“Interventions might pose risks of reduced income and even job loss, disproportionately affecting the most disadvantaged populations... Special attention should be given to protections for vulnerable populations, such as homeless, incarcerated, older, or disabled individuals, and undocumented migrants,” they added.