Mass masking in the COVID-19 epidemic: people need guidance
Authors: Chi Chiu Leung, Tai Hing Lam, Kar Keung Cheng
Journal: The Lancet (2020)

As the spread of coronavirus disease 2019 (COVID-19) outside China is accelerating, we urge policy makers to reconsider the role of masking. The non-specific symptoms at early stages of COVID-19 and absence of clear transmission links have defied conventional containment strategy by case isolation and contact quarantine.1Guan WJ Ni ZY Hu Y et al.Clinical characteristics of the 2019 novel coronavirus infection in China.NEJM. 2020; (published online Feb 28.)DOI:10.1056/NEJMoa2002032Crossref Scopus (20389) Google Scholar So far, only compulsory social distancing, coupled with mass masking, appears to be successful, at least temporarily, in China. However, whether such an approach is sustainable in the Chinese economy or enforceable in other social systems is doubtful. WHO recommends against wearing masks in community settings because of lack of evidence.2WHOAdvice on the use of masks in the community, during home care and in health care settings in the context of the novel coronavirus (2019-nCoV) outbreak: interim guidance.https://apps.who.int/iris/handle/10665/330987Date: 29 January 2020Date accessed: March 2, 2020Google Scholar However, absence of evidence of effectiveness should not be equated to evidence of ineffectiveness, especially when facing a novel situation with limited alternative options. It has long been recommended that for respiratory infections like influenza, affected patients should wear masks to limit droplet spread. If everyone puts on a mask in public places, it would help to remove stigmatisation that has hitherto discouraged masking of symptomatic patients in many places.3Teasdale E Santer M Geraghty AW Little P Yardley L Public perceptions of non-pharmaceutical interventions for reducing transmission of respiratory infection: systematic review and synthesis of qualitative studies.BMC Public Health. 2014; 14: 589Crossref PubMed Scopus (81) Google Scholar Furthermore, transmission from asymptomatic infected individuals has been documented for COVID-19, and viral load is particularly high at early disease stage.4Bai Y Yao L Wei T et al.Presumed asymptomatic carrier transmission of COVID-19.JAMA. 2020; (published online Feb 21.)DOI:10.1001/jama.2020.2565Crossref PubMed Scopus (3085) Google Scholar, 5Zou L Ruan F Huang M et al.SARS-CoV-2 viral load in upper respiratory specimens of infected patients.NEJM. 2020; (published online Feb 19.)DOI:10.1056/NEJMc2001737Crossref PubMed Scopus (3469) Google Scholar Masking, as a public health intervention, would probably intercept the transmission link and prevent these apparently healthy infectious sources. Global shortage of disposable surgical masks is a real and expanding problem. So-called mass mask panic has occured irrespective of advice from public health authorities. Panic buying of masks in Hong Kong has gone unresolved for more than 30 days, and a similar situation seems to be developing in Italy. People wear masks to protect themselves in close person-to-person contacts, but unintentionally, they are protecting each other through source control. Disposable surgical masks and their technical specifications were designed specifically for the protection of health-care workers during occupational exposures. Cloth masks were used by surgeons successfully during operations before disposable masks were available. In real life, most people in all seriously affected areas are reusing their disposable masks. All governments must prepare to handle the probable mass panic and explore other sustainable alternatives to the disposable masks for effective source control in community settings. With the imminent pandemic, health authorities need to decide rapidly whether they should adopt mass masking in their own localities and make advance preparations to avoid confusion and chaos in the anticipated challenges ahead. We declare no competing interests.