학술논문
Effectiveness of Face Mask or Respirator Use in Indoor Public Settings for Prevention of SARS-CoV-2 Infection — California, February–December 2021
Document Type
article
Author
Andrejko, Kristin L; Pry, Jake M; Myers, Jennifer F; Fukui, Nozomi; DeGuzman, Jennifer L; Openshaw, John; Watt, James P; Lewnard, Joseph A; Jain, Seema; Abdulrahim, Yasmine; Barbaduomo, Camilla M; Bermejo, Miriam I; Cheunkarndee, Julia; Cornejo, Adrian F; Corredor, Savannah; Dabbagh, Najla; Dong, Zheng N; Dyke, Ashly; Fang, Anna T; Felipe, Diana; Frost, Paulina M; Ho, Timothy; Javadi, Mahsa H; Kaur, Amandeep; Lam, Amanda; Li, Sophia S; Miller, Monique; Ni, Jessica; Park, Hyemin; Poindexter, Diana J; Samani, Helia; Saretha, Shrey; Spencer, Maya; Spinosa, Michelle M; Tran, Vivian H; Walas, Nikolina; Wan, Christine; Xavier, Erin
Source
MMWR Morbidity and Mortality Weekly Report. 71(6)
Subject
Language
Abstract
The use of face masks or respirators (N95/KN95) is recommended to reduce transmission of SARS-CoV-2, the virus that causes COVID-19 (1). Well-fitting face masks and respirators effectively filter virus-sized particles in laboratory conditions (2,3), though few studies have assessed their real-world effectiveness in preventing acquisition of SARS-CoV-2 infection (4). A test-negative design case-control study enrolled randomly selected California residents who had received a test result for SARS-CoV-2 during February 18-December 1, 2021. Face mask or respirator use was assessed among 652 case-participants (residents who had received positive test results for SARS-CoV-2) and 1,176 matched control-participants (residents who had received negative test results for SARS-CoV-2) who self-reported being in indoor public settings during the 2 weeks preceding testing and who reported no known contact with anyone with confirmed or suspected SARS-CoV-2 infection during this time. Always using a face mask or respirator in indoor public settings was associated with lower adjusted odds of a positive test result compared with never wearing a face mask or respirator in these settings (adjusted odds ratio [aOR] = 0.44; 95% CI = 0.24-0.82). Among 534 participants who specified the type of face covering they typically used, wearing N95/KN95 respirators (aOR = 0.17; 95% CI = 0.05-0.64) or surgical masks (aOR = 0.34; 95% CI = 0.13-0.90) was associated with significantly lower adjusted odds of a positive test result compared with not wearing any face mask or respirator. These findings reinforce that in addition to being up to date with recommended COVID-19 vaccinations, consistently wearing a face mask or respirator in indoor public settings reduces the risk of acquiring SARS-CoV-2 infection. Using a respirator offers the highest level of personal protection against acquiring infection, although it is most important to wear a mask or respirator that is comfortable and can be used consistently.