Some countries have been devastated by the novel coronavirus, and others have escaped lightly.
Why the extreme differences? The main one is that countries that quickly resorted to widespread mask-wearing had far lower death rates and shorter outbreaks, a new study argues.
The authors looked at coronavirus death rates in 198 countries, trying to see why some had painfully high death rates and others very low.
“What we found was that of the big variables that you can control which influence mortality, one was wearing masks,” says Christopher Leffler of Virginia Commonwealth University, one of the study’s authors.
“If you wore masks early in your outbreak, you had much lower mortality.
“It wasn’t just by a few per cent, it was up to a hundred times less mortality. The countries that introduced masks from the very beginning of their outbreak have had hardly any deaths.”
Most of the countries that had low death rates were in East Asia, especially South Korea and Japan.
“You also have Taiwan, Hong Kong, Macau — there are lots of countries that used masks early on. Vietnam and Thailand are good examples — they’ve kept per capita mortality very low,” Leffler says.
A superspreader event at a church in South Korea supports the argument, he says, since the people at that gathering weren’t wearing masks.
Outside East Asia, Slovakia and the Czech Republic moved to require masks early on and had low death rates as a result, Leffler argues.
“If you look at Latin America, Venezuela is an example where the very first day that they confirmed a case, the president demonstrated how to wear a mask on television. You can find around the world examples from many regions.”
Venezuela has so far avoided the worst of the virus, suffering far less than neighbouring Brazil.
Masks worn by ordinary people, perhaps improvised from fabric that people happen to have around, are still helpful even if they’re worn much less strictly than masks in a hospital, he says. What’s important is that a critical mass of people wear some kind of mask, especially indoors.
“It’s important to understand that the masks don’t have to be perfect. If everybody wears them and they only block half of the transmission, this has an enormous effect at a population level.”
A Cambridge University study released earlier this month reached similar conclusions.
“Research shows that even homemade masks made from cotton T-shirts or dishcloths can prove 90 per cent effective at preventing transmission,” it argued.
“Crude homemade masks primarily reduce disease spread by catching the wearer’s own virus particles, breathed directly into fabric, whereas inhaled air is often sucked in around the exposed sides of the mask.”
Simple cloth masks have a long history in the West during times of respiratory disease going back to the 1918 flu epidemic, Leffler says.
“In North America, where the virus is circulating, mask-wearing is the most important thing that could be done to get this under control.”