How far do distancing, masks reduce Covid-19 spread?
A new study in The Lancet provides evidence on the optimum use of simple interventions to help flatten the epidemic curve. Part funded by the World Health Organization and conducted by researchers worldwide, the paper pooled 44 comparative studies (7 on COVID-19, 26 on SARS and 11 on MERS) that involved 25,697 participants and performed a meta-analysis to understand how effective was social distancing, wearing eye protection and wearing a mask on preventing the spread of Covid-19.
Current policies of at least 1 m physical distancing are associated with a large reduction in infection, and distances of 2 m might be more effective, the study said. “These data also suggest that wearing face masks protects people (both health-care workers and the general public) against infection by these coronaviruses, and that eye protection could confer additional benefit. However, none of these interventions afforded complete protection from infection, and their optimum role might need risk assessment and several contextual consideration.”
Nine studies that compared the effects of social distancing found that 3 per cent of the people caught the coronavirus infection if they maintained a distance of more than1m, compared to 13 per cent if the distance maintained was less than 1m.
Thirteen studies that examined the effect of wearing an eye protective device found that the risk of catching the infection was 6 per cent among those who wore an eye protective equipment, compared to 16 per cent among those who did not.
Ten studies that examined the efficacy of wearing a face mask showed that if you wore a mask, the risk of catching the infection was 3 per cent, compared to 17 per cent if you did not.
Dr Sundeep Salvi, Director of the Pulmocare Research and Education Foundation in Pune, told The Indian Express that the end of the lockdown is not the end of the pandemic, but the beginning of a long drawn-up battle against the virus, where social distancing, hand hygiene, wearing eye protection and wearing a mask are the best options at hand to reduce the spread.
Among these, wearing a mask seems to be the most useful intervention. A cloth mask made of cotton quilt, or a hybrid mask made up of cotton and chiffon, or cotton and silk offer good quality protection, he added.