July 14, 2020
Studies Show Importance of Face Coverings in Limiting Spread of COVID-19
By Kelly Young
Edited by David G. Fairchild, MD, MPH
A trio of studies takes a closer look at face mask use in the U.S.
Use of cloth face masks around the country increased significantly from April — when the CDC first recommended their use to prevent the spread of SARS-CoV-2 — to May, according to an MMWR study.
Researchers surveyed 400 U.S. adults in April and another 400 in May about whether they used cloth face coverings when they left the house in the past week. The prevalence of face mask–wearing increased from 62% to 76% overall, with increases reported in all socioeconomic groups. Lower rates of mask-wearing in May were seen in the following groups: people in their 40s (68%), people with lower incomes, and people living with others at no cost (57%).https://www.cdc.gov/mmwr/volumes/69/wr/mm6928e3.htm?s_cid=mm6928e3_w
A separate study in MMWR describes the lack of SARS-CoV-2 transmission at a Missouri hair salon where face masks were required by city ordinance. Two stylists tested positive for SARS-CoV-2. Before their results came back, they saw 139 customers while symptomatic. Of the 100 clients who were interviewed, 98% were also wearing face coverings. No clients developed symptoms. Four household contacts of one stylist tested positive.
https://www.cdc.gov/mmwr/volumes/69/wr/mm6928e2.htm?s_cid=mm6928e2_w
And finally, in JAMA, researchers report a reduction in SARS-CoV-2 positivity rates among healthcare workers at Mass General Brigham after universal masking was put into place, from 14.7% to 11.5%.
https://jamanetwork.com/journals/jama/fullarticle/2768533
CDC Director Robert Redfield and other agency officials conclude in a JAMA editorial: “At this critical juncture when COVID-19 is resurging, broad adoption of cloth face coverings is a civic duty, a small sacrifice reliant on a highly effective low-tech solution that can help turn the tide favorably in national and global efforts against COVID-19.”
