Update Alert 6: Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community Settings
Authors: Roger Chou, Tracy Dana, Rebecca Jungbauer
Journal: Annals of Internal Medicine (2021)

Letters13 July 2021Update Alert 6: Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community SettingsFREERoger Chou, MD, Tracy Dana, MLS, and Rebecca Jungbauer, DrPHRoger Chou, MDPacific Northwest Evidence-based Practice Center and Oregon Health & Science University, Portland, OregonSearch for more papers by this author, Tracy Dana, MLSPacific Northwest Evidence-based Practice Center and Oregon Health & Science University, Portland, OregonSearch for more papers by this author, and Rebecca Jungbauer, DrPHPacific Northwest Evidence-based Practice Center and Oregon Health & Science University, Portland, OregonSearch for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/L21-0393 SectionsSupplemental MaterialAboutVisual AbstractPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail This is the sixth update alert for a living, rapid review on the use of masks for prevention of respiratory virus infections, including SARS-CoV-2, in health care and community settings (1). The first 3 updates were monthly, and the interval was switched to bimonthly for subsequent updates. The prior update search (through April 2) (2) found no eligible studies. Update searches were done from 3 April 2021 to 2 June 2021, using the same search strategies as the original review. The update searches identified 492 citations. Two studies (3, 4) on the use of masks and the prevention of SARS-CoV-2 done in a health care setting were added for this update; no new studies done in a community setting were identified through literature searches (Supplement Tables 1 to 3).On the basis of 3 observational studies (5–7) comparing N95 respirators with surgical masks for prevention of SARS-CoV-2 in health care settings, the strength of evidence was previously assessed as insufficient because of inconsistent effects across studies (Supplement Table 4). One new cross-sectional study done in the United States found no statistically significant differences in risk for SARS-CoV-2 seropositivity between N95 respirator and surgical mask use (4). The study had methodological limitations, including potential recall bias and a 50% participation rate. In addition, adjusted risk estimates were not reported. Therefore, the strength of evidence for N95 use versus surgical mask use remains insufficient (Supplement Table 4). Regarding consistency of mask use, the evidence was previously assessed as insufficient on the basis of 1 study that found that consistent N95 (adjusted odds ratio, 0.83 [95% CI, 0.72 to 0.95]) or surgical mask (adjusted odds ratio, 0.86 [CI, 0.75 to 0.98]) use was associated with reduced risk for SARS-CoV-2 infection relative to inconsistent use (8). New evidence from a cross-sectional study done in France also found that consistent face mask use compared with inconsistent use was associated with a reduced risk for SARS-CoV-2 infection (adjusted odds ratio, 0.07 [CI, 0.003 to 0.56]) (3). Because of inconsistent estimates and few studies, the strength of evidence for consistent mask use and risk for SARS-CoV-2 infection remains insufficient. Other strength of evidence ratings related to mask use in health care settings and risk for SARS-CoV-2 infection also remain insufficient (Supplement Table 4).No new studies evaluated the effects of mask use in a community setting or risk for SARS-CoV-2 infection, Middle East respiratory syndrome–CoV infection, or influenza or influenza-like illness in health care workers. In community settings, the strength of evidence remains low for an association between any mask use versus no mask use or surgical mask use versus no mask use and decreased risk for SARS-CoV-1 infection. As with prior updates, there were no studies on the effectiveness and safety of mask reuse or extended use.Given few new eligible studies and little change in conclusions after 1 year of monthly or bimonthly updates, we will update and reevaluate the need for continued updates again in 6 months.References1. Chou R, Dana T, Jungbauer R, et al. Masks for prevention of respiratory virus infections, including SARS-CoV-2, in health care and community settings. A living rapid review. Ann Intern Med. 2020;173:542-555. [PMID: 32579379] doi:10.7326/M20-3213 LinkGoogle Scholar2. Chou R, Dana T, Jungbauer R, et al. Surveillance comment. Ann Intern Med. 13 April 2021. Accessed at www.acpjournals.org/doi/10.7326/m20-3213 on 1 July 2021. Google Scholar3. Davido B, Gautier S, Riom I, et al; Garches COVID-19 Collaborative Group. The first wave of COVID-19 in hospital staff members of a tertiary care hospital in the greater Paris area: a surveillance and risk factors study. Int J Infect Dis. 2021;105:172-179. [PMID: 33607301] doi:10.1016/j.ijid.2021.02.055 CrossrefMedlineGoogle Scholar4. Fletcher JJ, Feucht EC, Hahn PY, et al. Health care acquired COVID-19 is less symptomatic than community acquired disease among healthcare workers. Infect Control Hosp Epidemiol. 2021:1-28. [PMID: 33853694] doi:10.1017/ice.2021.167 CrossrefMedlineGoogle Scholar5. Piapan L, De Michieli, Ronchese F, et al. COVID-19 outbreak in healthcare workers in hospitals in Trieste, North-east Italy. J Hosp Infect. 2020;106:626-628. [PMID: 32805309] doi:10.1016/j.jhin.2020.08.012 CrossrefMedlineGoogle Scholar6. Sims MD, Maine GN, Childers KL, et al; BLAST COVID-19 Study Group. COVID-19 seropositivity and asymptomatic rates in healthcare workers are associated with job function and masking. Clin Infect Dis. 2020. [PMID: 33150375] doi:10.1093/cid/ciaa1684 CrossrefMedlineGoogle Scholar7. Venugopal U, Jilani N, Rabah S, et al. SARS-CoV-2 seroprevalence among health care workers in a New York City hospital: a cross-sectional analysis during the COVID-19 pandemic. Int J Infect Dis. 2021;102:63-69. [PMID: 33075539] doi:10.1016/j.ijid.2020.10.036 CrossrefMedlineGoogle Scholar8. Akinbami LJ, Vuong N, Petersen LR, et al. SARS-CoV-2 seroprevalence among healthcare, first response, and public safety personnel, Detroit metropolitan area, Michigan, USA, May-June 2020. Emerg Infect Dis. 2020;26:2863-2871. [PMID: 32956614] doi:10.3201/eid2612.203764 CrossrefMedlineGoogle Scholar Comments 0 Comments Sign In to Submit A Comment Author, Article, and Disclosure InformationAuthors: Roger Chou, MD; Tracy Dana, MLS; Rebecca Jungbauer, DrPHAffiliations: Pacific Northwest Evidence-based Practice Center and Oregon Health & Science University, Portland, OregonDisclaimer: The authors of this manuscript are responsible for its content. Statements in the manuscript do not necessarily represent the official views of or imply endorsement by the Agency for Healthcare Research and Quality or U.S. Department of Health and Human Services.Disclosures: Disclosures can be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=L21-0393.Corresponding Author: Roger Chou, MD, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Mail Code BICC, Portland, OR 97239; e-mail, chour@ohsu.edu.This article was published at Annals.org on 13 July 2021. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetailsSee AlsoUpdate Alert: Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community Settings Roger Chou , Tracy Dana , Rebecca Jungbauer , Chandler Weeks , and Marian S. McDonagh Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community Settings Roger Chou , Tracy Dana , Rebecca Jungbauer , Chandler Weeks , and Marian S. McDonagh Update Alert 2: Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community Settings Roger Chou , Tracy Dana , Rebecca Jungbauer , Chandler Weeks , and Marian S. McDonagh Update Alert 3: Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community Settings Roger Chou , Tracy Dana , Rebecca Jungbauer , and Chandler Weeks Update Alert 4: Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community Settings Roger Chou , Tracy Dana , Rebecca Jungbauer , and Chandler Weeks Update Alert 5: Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community Settings Roger Chou , Tracy Dana , Rebecca Jungbauer , and Chandler Weeks Update Alert 7: Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community Settings Roger Chou , Tracy Dana , Rebecca Jungbauer Update Alert 8: Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community Settings Roger Chou , Tracy Dana , Rebecca Jungbauer Major Update: Masks for Prevention of SARS-CoV-2 in Health Care and Community Settings—Final Update of a Living, Rapid Review Roger Chou , and Tracy Dana Metrics Cited byProtective behavior and SARS-CoV-2 infection risk in the population – Results from the Gutenberg COVID-19 studyUpdate Alert 7: Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community SettingsRoger Chou, MD, Tracy Dana, MLS, Rebecca Jungbauer, DrPHPros and cons of using face masks for non-specific prevention of new coronavirus infection September 2021Volume 174, Issue 9 Page: W68 ePublished: 13 July 2021 Issue Published: September 2021 Copyright & PermissionsCopyright © 2021 by American College of Physicians. 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