Arnold, Forest W

Bordon, Jose

Glynn, Alex

English

University of Louisville

University of Louisville Journal of Respiratory InfectionsEDITORIALWhy Should People Use Face Masks in the Time of COVID? The JRIPositionJose Bordon1∗, MD PhD; Alex Glynn2, MA; Forest W. Arnold2, DO MSc1George Washington University School of Medicine and Health Sciences, Department of Medicine, Washington, D.C., USA; 2Center of Excellence for Research inInfectious Diseases, Division of Infectious Diseases, University of Louisville, Louisville, KY, USA∗ jbordon@dc-whi.orgRecommended Citation: Bordon J, Glynn A, Arnold FW. Why should people use face masks in the time of COVID? The JRI position. Univ Louisville J Respir Infect2021; 5(1):Article 27.The COVID-19 pandemic is likely an epic reshaping ofhuman behavior across the globe. Beyond our knowl-edge of previous pandemics and infections, COVID-19 demanded extraordinary changes in our lifestyle.The virus spread rapidly across the globe due to itshigh transmissibility, and the extraordinary death tollwas unprecedented. In the early stages of this pan-demic, there was a sense of powerlessness leading usto isolation from public gathering. Under the lead-ership of the World Health Organization (WHO), theCenters for Disease Control and Prevention (CDC), andother organizations, the predominant response was touse preventive measures, including social distancing,hand washing and face masks. These measures havebeen very effective in preventing infection and contain-ing the spread of infection in previous epidemics andpandemics. Ongoing protective measures are critical tomitigate the pandemic; however, controversies persistconcerning the use of face masks as a protection mea-sure against COVID.One of the greatest privileges of today’s world is theright to have our own opinion on any finding andto share it through digital media. Diversity of opin-ion makes our world rich with ideas; however, someopinions—well-intentioned or otherwise—can result insuffering and loss of lives.Constructive scientists recognize the limitations of ourknowledge and develop hypotheses in efforts to ex-pand it. Unfortunately, in the time of the infodemic,not all medical research—particularly articles postedas preprints—undergo rigorous scientific scrutiny. Ourjournal previously published our position on preprintsas potentially unreliable sources of knowledge.[1] Fur-thermore, traditional and social media are being usedto spread misinformation and disinformation despitethe efforts of infodemic surveillance organizations. Inthis note, we would like to address the controversy re-garding whether the use of face masks by people in thecommunity prevents infection and the spread of infec-tion to others.The CDC recommends the use of a face mask consistingof two or more layers of fabric for those not fully vac-cinated or who have a weak immune system; masksare universally recommended (regardless of vaccina-tion or immune status) in indoor public places and inpublic transportation to mitigate the spread of the Deltavariant of SARS-CoV-2. For these purposes, the U.S.Food & Drug Administration defines a face mask as“a mask, with or without a face shield, that covers theuser’s nose and mouth and may or may not meet fluidbarrier or filtration efficiency levels”.[2] In the case ofnon-medical face masks, filtration efficacy is variable.An important point for clarification is the mask filtra-tion efficiency for particles including the SARS-CoV-2virus. Typically, the virus is transmitted through the airby droplets—particles greater than 5 µm in diameter—however, it can also be transmitted in smaller particles(<1 µm). Filtration efficiency is the percentage of par-ticles blocked by the mask. As a reference, medicalmasks are certified by the American Society for Testingand Material (ASTM) International with an efficiency≥95% (Level 1) or ≥98% (Levels 2 and 3) for particles0.1 µm in diameter.[3]What does the current literature tell us?Filtration efficiencyVan der Sande et al. reported the inward filtration effi-ciency for a 1-layer tea towel at 55–77% and outward at17% for 0.02–1 µm particles.[4] The low outward effi-ciency could be explained by the 1-layer compositionand the fact that particles are expelled from the up-per respiratory tract and mouth, which are high pres-ULJRI | https://ir.library.louisville.edu/jri/vol5/iss1/27 1ULJRI Why Should People Use Face Masks in the Time of COVID?sure spaces. Dato et al. reported an efficiency >90%for multilayer homemade masks. Overall, if we followthe CDC recommendation to use a ≥2-layer fabric facemask, substantial protection is expected for the user, aswell as substantial mitigation of viral spread.[5]Effectiveness of mask useThe effectiveness of face mask use against past andpresent pandemics is well-attested in the literature. Thefollowing is a summary of the findings of five system-atic reviews and meta-analyses on the subject.In 2020, few studies of mask use against COVID-19 hadbeen published; evidence primarily consisted of stud-ies concerning other coronaviruses and other respira-tory pathogens. In June 2020, Chu et al. found thatacross six studies, persons wearing face masks wereat one-third the risk of infection from SARS-CoV andMERS-CoV, Betacoronaviruses similar to SARS-CoV-2, compared to those with uncovered faces (adjustedodds ratio [OR] 0.33, 95% confidence interval [CI] 0.17–0.61, I2=76%).[6] Liang et al. (July 2020) similarly foundthat across 21 studies, including one on SARS-CoV-2,face mask users were at 35% the risk of infection fromrespiratory viruses compared to those with uncoveredfaces (pooled OR 0.35, 95% CI 0.24–0.51, I2=60%).[7]In subgroup analyses, the OR [95% CI] for healthcareworkers across 12 studies was 0.20 [0.11–0.37] and fornon-healthcare workers across eight studies was 0.53[0.36–0.79].By 2021, richer literature on mask use against SARS-CoV-2 specifically was available for meta-analysis. InJanuary 2021, Tabatabaeizadeh et al. demonstrated asignificant reduction in SARS-CoV-2 infection risk withface mask use across four studies (pooled relative risk[RR] 0.12, 95% CI: 0.06–0.27, P<0.001).[8] In a meta-analysis by Hemmer et al. (February 2021) of 29 stud-ies on SARS-CoV, MERS-CoV, and SARS-CoV-2, maskuse was associated with one-third odds of infection(adjusted OR 0.04, 95% CI: 0.004–0.3 [N95 respirators]and 0.33, 95% CI 0.17–0.61 [other masks]).[9] Li et al.(July 2021) similarly found that across six studies, wear-ing a mask was associated with significantly reducedodds of COVID-19 infection (OR 0.38, 95% CI: 0.21–0.69, I2=54.1%).[10]Effectiveness of government-mandated mask useA 2021 cross-sectional study found that a 10% increasein self-reported mask use was associated with a morethan three-fold increase in odds of transmission control(multivariate logistic regression model with 10-pointextrapolation, adjusting for confounders, physical dis-tancing, and a time trend).[11] However, the studyalso found no statistically significant change in aver-age mask usage as a result of government mandate. Bycontrast, MacIntyre et al. observed a statistically signifi-cant association between mask mandates and mask usein univariate regression analysis (P<0.001).[12]In a 2020 ecological study, Fang et al. found that coun-ties in states with face mask mandates were at signif-icantly less risk of COVID-19 incidence, with an ad-justed risk ratio of 0.8462 (95% CI: 0.7592–0.9433).[13]This association was observed during the second surge(May 28–September 12, 2020), but not during the firstsurge (up to May 28, 2020).A study of SARS-CoV-2 spread prior to the start ofvaccination found that the rapid implementation ofmask mandates was associated with lower rates of in-fection.[14] States that implemented mask mandates3–6 months after the start of their respective SARS-CoV-2 epidemic (defined as ≥50 cases present in thestate) had an infection rate 1.61 times higher thanstates that implemented a mask mandate within onemonth (adjusted rate ratio 1.61 (95% CI: 1.23–2.10),P<0.001). States that implemented mask mandates af-ter six months or did not implement mask mandateshad an infection rate 2.16 times higher than states thatimplemented a mask mandate within one month (ad-justed rate ratio 2.16 (95% CI: 1.64–2.88, P<0.0001).ConclusionDespite the many medical resources at our disposal,the landscape of the COVID-19 epidemic looks like adisastrous battlefield in the US. As of August 25, 2021,there have been 38,077,814 confirmed cases of COVID-19 and 630,840 deaths, while only 51.6% of the US pop-ulation is fully vaccinated.[15, 16] The most recent com-plete epidemiological week (August 15–21, 2021) sawnearly a million new cases of COVID-19 reported to theCDC, the greatest surge since 1.7 million were reportedat the beginning of 2021 (Figure 1). The surge is largelyamong the unvaccinated and demands extraordinarymeasures to contain it. Regardless of the relatively lim-ited data and lack of optimal randomized controlled tri-als to confirm the benefit of face masks against COVID-19, the available data indicate a moderate protectionthat is crucial to protect our communities. We stronglyrecommend the use of face masks to the public in linewith the recommendations of the CDC and the Infec-tious Diseases Society of America.ULJRI | https://ir.library.louisville.edu/jri/vol5/iss1/27 2ULJRI Why Should People Use Face Masks in the Time of COVID?Figure 1. Cases of COVID-19 reported to the Centers for Disease Control and Prevention (CDC) per week.ULJRI | https://ir.library.louisville.edu/jri/vol5/iss1/27 3ULJRI Why Should People Use Face Masks in the Time of COVID?Acknowledgements: The authors would like to thank Jes-sica Petrey, MSLS, for conducting the literature search.Published: August 25, 2021Copyright: © 2021 The author(s). This original article isbrought to you for free and open access by ThinkIR: The Uni-versity of Louisville’s Institutional Repository. For more infor-mation, please contact thinkir@louisville.edu. This article isdistributed under the terms of the Creative Commons Attribu-tion 4.0 International License (CC BY 4.0), which permits un-restricted use, distribution, and reproduction in any medium,provided the original author and source are credited.Funding Source: The author(s) received no specific fundingfor this workConflict of Interest: All authors declared no conflict of inter-est in relation to the main objective of this work.References1. Arnold F, Buckner K, Glynn A, Petrey J, Bordon J. ToPreprint or Not to Preprint. Univ Louisville J Respir Infect2021; 5(1):Article 12. doi: 10.18297/jri/vol5/iss1/12.2. U.S. Food & Drug Administration. Face Masks, IncludingSurgical Masks, and Respirators for COVID-19. Available at:https://www.fda.gov/medical-devices/coronavirus-covid-19-and-medical-devices/face-masks-including-surgical-masks-and-respirators-covid-19. Accessed 25 August 2021.3. American Society for Testing and Materials. Under-standing ASTM Levels for face masks. Available at:https://www.coronavirus.kdheks.gov/DocumentCenter/View/1416/Understanding-ASTM-Levels-for-facemasks-PDF---7-30-20. Accessed 25 August 2021.4. van der Sande M, Teunis P, Sabel R. Professional andhome-made face masks reduce exposure to respiratory in-fections among the general population. PLoS One 2008;3(7):e2618. doi: 10.1371/journal.pone.0002618. PMID:18612429.5. Dato VM, Hostler D, Hahn ME. Simple respiratorymask. Emerg Infect Dis 2006; 12(6):1033-4. doi:10.3201/eid1206.051468. PMID: 16752475.6. Chu DK, Akl EA, Duda S, Solo K, Yaacoub S, SchünemannHJ. Physical distancing, face masks, and eye protectionto prevent person-to-person transmission of SARS-CoV-2and COVID-19: a systematic review and meta-analysis.Lancet 2020; 395(10242):1973-87. doi: 10.1016/s0140-6736(20)31142-9. PMID: 32497510.7. Liang M, Gao L, Cheng C, et al. Efficacy of facemask in preventing respiratory virus transmission: A sys-tematic review and meta-analysis. Travel Med Infect Dis2020; 36:101751. doi: 10.1016/j.tmaid.2020.101751. PMID:32473312.8. Tabatabaeizadeh SA. Airborne transmission of COVID-19and the role of face mask to prevent it: a systematic re-view and meta-analysis. Eur J Med Res 2021; 26(1):1. doi:10.1186/s40001-020-00475-6. PMID: 33388089.9. Hemmer CJ, Hufert F, Siewert S, Reisinger E. ProtectionFrom COVID-19. Dtsch Arztebl Int 2021; 118(5):59-65. doi:10.3238/arztebl.m2021.0119. PMID: 33785117.10. Li Y, Liang M, Gao L, et al. Face masks to preventtransmission of COVID-19: A systematic review and meta-analysis. Am J Infect Control 2021; 49(7):900-6. doi:10.1016/j.ajic.2020.12.007. PMID: 33347937.11. Rader B, White LF, Burns MR, et al. Mask-wearing andcontrol of SARS-CoV-2 transmission in the USA: a cross-sectional study. Lancet Digit Health 2021; 3(3):e148-e57. doi:10.1016/s2589-7500(20)30293-4. PMID: 33483277.12. MacIntyre CR, Nguyen P-Y, Chughtai AA, et al. Maskuse, risk-mitigation behaviours and pandemic fatigue dur-ing the COVID-19 pandemic in five cities in Australia,the UK and USA: A cross-sectional survey. InternationalJournal of Infectious Diseases 2021; 106:199-207. doi:10.1016/j.ijid.2021.03.056.13. Fang F, Mu L, Zhu Y, Rao J, Heymann J, ZhangZF. Long-Term Exposure to PM(2.5), face mask Mandates,Stay Home Orders and COVID-19 Incidence in the UnitedStates. Int J Environ Res Public Health 2021; 18(12). doi:10.3390/ijerph18126274. PMID: 34200600.14. Krishnamachari B, Morris A, Zastrow D, Dsida A, HarperB, Santella AJ. The role of mask mandates, stay at home or-ders and school closure in curbing the COVID-19 pandemicprior to vaccination. AJIC: American Journal of Infection Con-trol 2021; 49(8):1036-42. doi: 10.1016/j.ajic.2021.02.002.15. Centers for Disease Control and Prevention. COVID-19 Vaccinations in the United States. Available at: https://covid.cdc.gov/covid-data-tracker/#vaccinations vacc-total-admin-rate-total. Accessed 25 August 2021.16. Center for Systems Science and Engineering at JohnsHopkins University. COVID-19 Dashboard. Available at:https://coronavirus.jhu.edu/map.html. Accessed 25 August2021.ULJRI | https://ir.library.louisville.edu/jri/vol5/iss1/27 4

Why Should People Use Face Masks in the Time of COVID? The JRI Position

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Why Should People Use Face Masks in the Time of COVID? The JRI Position

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