Brenda Goodman, MA
A large, real-world test of face masks in Bangladesh shows that masks work to reduce community spread of COVID-19. It also shows that surgical masks are more effective than cloth face coverings.
The study, which was published ahead of peer review, demonstrates the power of careful investigation and offers a host of lessons about mask wearing that will be important worldwide. One key finding of the study, for example, is that wearing a mask doesn’t lead people to abandon social distancing, something public health officials had feared might happen if masks gave people a false sense of security.
“What we really were able to achieve is to demonstrate that masks are effective against COVID-19, even under a rigorous and systematic evaluation that was done in the throes of the pandemic,” said Ashley Styczynski, MD, who was an infectious disease fellow at Stanford University when she collaborated on the study with other colleagues at Stanford, Yale, and Innovations for Poverty Action (IPA), a large research and policy nonprofit organization that currently works in 22 countries.
“And so, I think people who have been holding out on wearing masks because [they] felt like there wasn’t enough evidence for it, we’re hoping this will really help bridge that gap for them,” she said.
It included more than 600 unions — or local governmental districts in Bangladesh — and roughly 340,000 people.
Half of the districts were given cloth or surgical face masks along with continual reminders to wear them properly; the other half were tracked with no intervention. Blood tests of people who developed symptoms during the study verified their infections.
Compared to villages that didn’t mask, those in which masks of any type were worn had about 9% fewer symptomatic cases of COVID-19. The finding was statistically significant and was unlikely to have occurred by chance alone.