Mask-wearing linked to reduced Covid-19 transmission, study suggests

Mask-wearing is associated with better control of Covid-19 transmission in communities, a new study published in The Lancet Digital Health journal has revealed.

More than 300,000 people in the US took part in the study, which is based on observational data and mathematical modelling.

Health minister Zweli Mkhize, speaking about the new coronavirus variant on Monday, said there was early evidence that the second wave of infections was being brought under control and he attributed this to measures like the wearing of masks.

“When we look at our records at this point, we see we are possibly beginning to see an inflection of the curve and the numbers [of infections] may be starting to decline. But it is too early to celebrate,” he said.

Mkhize said measures that worked during the first wave of infections — particularly wearing masks, social distancing and sanitising — were again proving effective.

Mask-wearing was made compulsory in public places after President Cyril Ramaphosa announced enhanced level 3 lockdown regulations.

“It has been encouraging to know that, despite the mutations, we are still able to protect ourselves with the armour we have established,” Mkhize said.

According to The Lancet, the study cannot prove mask-wearing is directly responsible for slowing virus transmission, and it is possible people who report wearing masks may also engage in other behaviours that reduce their risk of Covid-19 infection, such as increased hand washing, and this was not addressed in the study.

However, the findings lend further support for community adoption of face masks as an important intervention for reducing transmission.

Prof John Brownstein, senior author of the study, said: “Wearing face masks or face coverings in public spaces has been mandated by governments around the world to try to stem transmission of Covid-19.

“The aim is to provide a physical barrier that prevents the spread of virus-laden droplets. However, past evidence on the effectiveness of mask use against Covid-19 transmission is mixed and setting up randomised controlled trials to investigate this is challenging.

“Our findings, based on observational data, suggest a community benefit for wearing face masks for slowing the transmission of Covid-19. However, mandates alone may not be enough to increase mask use.

“We recommend policy makers consider additional strategies to evaluate and increase mask us to disrupt ongoing infections.”

Face masks may help to prevent Covid-19 transmission by protecting the wearer from becoming infected or preventing the wearer from passing on the virus if they are infected, or both.

Co-author Ben Rader said: “An important finding of this research is that mask-wearing is not a replacement for physical distancing and practising both at high levels had the best probability of controlling disease spread.”

Dr Christina Astley, a clinician and epidemiologist with Boston Children’s Hospital and Harvard Medical School, said: “Our findings suggest widespread use of face masks may help to control SARS-CoV-2 transmission.

“The world is facing a more transmissible coronavirus strain, hospitals are struggling with new cases and vaccination programmes are still being rolled out.

“Interventions are needed now to lower the burden on our health-care systems. This research provides additional evidence that interventions should include wearing face masks and physical distancing to protect ourselves.”

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