Unmasking the use of Masks in public setting in COVID-19 era
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There has been little debate or rational evidence about utility of masks as control measure in stopping or slowing spread of SARS-CoV-2 virus, the etiologic agent that is implicated in COVID-19 infections and their sequelae. Governmental units from federal to state and local authorities based on guidance or recommendations by national health agencies of their respective countries have issued mask wearing or face covering as a major public health measure to “flatten the curve” or reduce SARS-CoV-2 transmission. Many countries or governmental bodies have issued “mask-wearing” mandates for any person in outdoor public settings such as use of grocery stores, shopping malls, public transit, places of large gatherings and in areas with lack of physical distancing. However, the issuance of mask-wearing guidance lacks rigorous, solid scientific and medical data to justify universal masking protocol for the general population in most public, indoor settings, and outside in midst of nature or urban areas.
The undisputed use of wearing masks or face coverings is not well established science by any objective measure since large-scale randomized controlled trials (RCT) that assess the efficacy, benefits, risks, and cost analysis of universal masking is lacking thus far. Most public agencies and United States’ Center for Disease Control and Prevention (C.D.C.) base their public health measures based on “pseudo-science” and not even rigorous scientific principles. Moreover, previous studies on the seasonal influenza virus in healthcare and community spread has shown that cloth masking offers no reduction in virus transmission, and is worse than surgical or medical masks. 1
The three primary means by which respiratory viruses spread from infected person to uninfected person is by large droplets, aerosols (very small droplets) and fomites (infectious particles present on surfaces whereby touching them and then touching our noses, mouths or eyes can introduce our bodies to such pathogens). Several studies using the influenza virus and SARS-CoV-1 virus (the coronavirus that caused regional, mini pandemic in China in 2003) has shown that both cloth masks (single and double-layered) and medical/surgical masks were ineffective in preventing virus spread via aerosol transmission since pore size of these masks is larger than size of aerosolized viral particles.1
A recent, detailed review comparing masks and respirators (like N95 respirators) as source control (preventing spread from infected or asymptomatic person–another, not proven assumption) and personal protective equipment (PPE) has made revealing findings.1 Cloth masks provide little or no benefit for source control and as PPE (to prevent or reduce risk of acquiring respiratory infection). In contrast, surgical masks provided some modest measure to prevent transmission from infected person(s) to uninfected person(s). The respirators offered best protection to healthcare workers and frontline workers if the right filtering and correctly fitted ones were used as PPE. However, respirators are not recommended as source control since there are primarily reserved for healthcare and frontline workers in medical settings. Also, they are not beneficial without right filtering parameters and correct fit for general population use. Check out the studies listed below that are based on systematic review, meta-analysis and data from randomized clinical trial (RCTs) presenting evidence on utility of face masks as public health measure to reduce or prevent spread of virus-based respiratory transmissions.2-9 The bottom line of these studies is that general public masking is not effective or recommended as source control or PPE.
As they say “pictures are thousands words.” So let’s see if wearing masks or public masking mandates translate into “flattening the curve” or reducing rate of SARS-CoV-2 (or COVID-19) infections. The following pictorials are relevant since one can compare onset of mask mandates issued on the general population in public settings, the high rate of compliance (>90-95% of population wearing masks in public) and rate of COVID-19 infections.
(Source: One World Data: Twitter@yinonw)
If past history is any lesson, it looks like we have not really learned any lessons. In the last global pandemic of 1918 (influenza virus), despite the use of cloth maskings (yes, single, double and even multi-layered masks) and in many places by mandates, its use made no significant difference in terms of rate of infection and deaths.10 Interestingly, there is more evidence that SARS-2 coronavirus is transmitted, at least in indoor settings, not only by droplets but also by smaller aerosols. Cloth masks and to significant degree even surgical masks are not effective barriers to SARS-CoV-2 transmission by aerosols due to large pore size of materials and poor fitting of such masks. 11
See presentation below that shows how ill fitted masks are that the general public wears as source control and PPE; what a false sense of security or public health guidance by national health agencies like Center for Disease Control and Prevetion (C.D.C.), right?!
References:
2) Xiao J, Shiu E, Gao H, et al. Nonpharmaceutical Measures for Pandemic Influenza in Nonhealthcare Settings—Personal Protective and Environmental Measures. Emerging Infectious Diseases. 2020;26(5):967-975. doi:10.3201/eid2605.190994.
3) Henning Bundgaard, DMSc, Johan Skov Bundgaard, BSc, Daniel Emil Tadeusz Raaschou-Pedersen, BSc, et al
Annals of Internal Medicine Original Research, 18 November 2020 Effectiveness of Adding a Mask Recommendation to Other Public Health Measures to Prevent SARS-CoV-2 Infection in Danish Mask Wearers A Randomized Controlled Trial. https://doi.org/10.7326/M20-68174) https://www.cebm.net/covid-19/masking-lack-of-evidence-with-politics
5) https://www.medrxiv.org/content/10.1101/2020.05.01.20088260v1.full.pdf
6) Michael Klompas, M.D., M.P.H., Charles A. Morris, M.D., M.P.H., Julia Sinclair, M.B.A., Madelyn Pearson, D.N.P., R.N., and Erica S. Shenoy, M.D., Ph.D. Universal Masking in Hospitals in the Covid-19 Era, May 21, 2020 N Engl J Med 2020; 382:e63, DOI: 10.1056/NEJMp2006372
7) T Jefferson, MA Jones, L Al-Ansary, GA Bawazeer, EM Beller, J Clark, JM Conly, C Del Mar, E Dooley, E Ferroni, P Glasziou, T Hoffmann, S Thorning, ML van Driel. Physical interventions to interrupt or reduce the spread of respiratory viruses. Part 1 – Face masks, eye protection and person distancing: systematic review and meta-analysis, medRxiv 2020.03.30.20047217; doi: https://doi.org/10.1101/2020.03.30.20047217
8) Julii Brainard, Natalia Jones, Iain Lake, Lee Hooper, Paul R Hunter Facemasks and similar barriers to prevent respiratory illness such asCOVID-19: A rapid systematic review medRxiv 2020.04.01.20049528; doi:https://doi.org/10.1101/2020.04.01.20049528
9) MacIntyre CR, Seale H, Dung TC, et al A cluster randomised trial of cloth masks compared with medical masks in healthcare workers. BMJ Open 2015;5:e006577. doi: 10.1136/bmjopen-2014-006577
11)Lidia Morawska, Donald K Milton, It Is Time to Address Airborne Transmission of Coronavirus Disease 2019 (COVID-19), Clinical Infectious Diseases, Volume 71, Issue 9, 1 November 2020, Pages 2311–2313, https://doi.org/10.1093/cid/ciaa939
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