Face-Mask Use May Mitigate Spread of COVID-19
Daily COVID-19 growth rate significantly decreased after face-mask use mandated in public
THURSDAY, June 18, 2020 (HealthDay News) -- Requiring face-mask use in public may help to mitigate the spread of COVID-19, according to a report published online June 16 in Health Affairs.
Wei Lyu, and George L. Wehby, Ph.D., from the University of Iowa in Iowa City, examined changes in the daily county-level COVID-19 growth rates between March 31 and May 22, 2020. The effect of state government mandates in the United States for face-mask use in public, issued by 15 states and Washington, D.C., between April 8 and May 15, was examined.
The researchers observed a decrease in the daily COVID-19 growth rate by 0.9, 1.1, 1.4, 1.7, and 2.0 percentage points in one to five, six to 10, 11 to 15, 16 to 20, and 21+ days, respectively, after mandating face-mask use in public; all these declines were statistically significant. In comparing the actual cumulative daily cases with daily cases predicted by the model in the absence of a state public face-mask use mandate, estimates suggest that as many as 230,000 to 450,000 COVID-19 cases may have been averted by May 22, 2020, due to these mandates.
"As countries worldwide and states begin to relax social distancing restrictions and considering the high likelihood of a second COVID-19 wave in the fall/winter, requiring use of face masks in public might help in reducing COVID-19 spread," the authors write.