The case for face-masks for all

It seems so logical really. Wear a facemask to avoid COVID-19.

So why aren’t we all following Victoria’s lead and wearing masks when going out in public?

Well, apparently, to date there has been insufficient evidence proving that facemasks actually make a difference in reducing transmission when worn by healthy people. It has been shown they are effective when worn by people who have a virus, and it’s been shown they reduce transmission of the flu in flu season but as for their usefulness in containing COVID-19, even the WHO have been reluctant to advocate for universal facemasks.

But the evidence is coming.

Just recently a somewhat quirky although quite legitimate trial in the well-respected JAMA Network Open showed that facemask wearing, regardless of whether it was fabric or surgical significantly reduced the number of occasions a person touched their face – in particular their eyes, nose, and mouth.

If people are no longer touching their face, they are unlikely to be able to transmit the virus that would otherwise be on their hands to handrails, door handles, bathroom taps and the myriad of other surfaces that have been proven to remain contaminated for some time. And vice versa.

This may seem like a roundabout way to prove something that appears intuitive – surely wearing a mask reduces your risk to breathing in the respiratory virus? But that’s been the sticking point. The evidence shows droplet transmission is the dominant route spread of COVID-19, so someone has to cough or sneeze on you, or the virus can be transferred by hands from contaminated surfaces. Airborne transmission can occur but it is less likely. Airborne transmission tends to happen when a person with a high viral load comes in close contact with uninfected people in a confined space.

So avoiding transmission through reducing the number of times people touch their face is a very realistic goal. And that’s what these Chinese researchers set out to determine.

In this unique cross-sectional study the researchers looked at videos recorded in public areas in China, Japan, South Korea, Western Europe and the US before and during the COVID pandemic. These videos weren’t CCTV or staged but were videos used in tourism marketing or used for introducing local lifestyle.

The study involved looking at individuals in these videos and observing how many occasions they touched their face within a minute. Using this method and examining videos taken in the two years before the pandemic they were able to compare 4,700 individuals with 2,900 similar individuals observed in videos taken in February and March this year.

And facemasks, it appeared made a significant difference.

“General populations wearing masks displayed significant reductions in face-touching behaviour, with the exception of eye-touching behaviour,” they wrote.

Apparently China and South Korea experienced the greatest reduction in face-touching but they were also the countries wearing the most masks, so there were more cases to compare.

The study authors were quite definitive about the implications of their findings.

“Contamination of the face via hands and items might be a critical transmission route of SARS-CoV-2 in the general population in public areas. Therefore decreasing facial contamination is considered to be effective in preventing COVID-19 in the general population,” they said.

And for all those who need to see it in black and white…

“The reduction of face-touching behaviours by mask-wearing could contribute to curbing the COVID-19 pandemic,” was their final conclusion.

Ref: JAMA Netw Open. 2020;3(7):e2016924. doi:10.1001/jamanetworkopen.2020.16924

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