The role of community-wide wearing of face mask for control of coronavirus disease 2019 (COVID-19) epidemic due to SARS-CoV-2

Published:April 23, 2020DOI:



      Face mask usage by the healthy population in the community to reduce risk of transmission of respiratory viruses remains controversial. We assessed the effect of community-wide mask usage to control coronavirus disease 2019 (COVID-19) in Hong Kong Special Administrative Region (HKSAR).


      Patients presenting with respiratory symptoms at outpatient clinics or hospital wards were screened for COVID-19 per protocol. Epidemiological analysis was performed for confirmed cases, especially persons acquiring COVID-19 during mask-off and mask-on settings. The incidence of COVID-19 per million population in HKSAR with community-wide masking was compared to that of non-mask-wearing countries which are comparable with HKSAR in terms of population density, healthcare system, BCG vaccination and social distancing measures but not community-wide masking. Compliance of face mask usage in the HKSAR community was monitored.


      Within first 100 days (31 December 2019 to 8 April 2020), 961 COVID-19 patients were diagnosed in HKSAR. The COVID-19 incidence in HKSAR (129.0 per million population) was significantly lower (p<0.001) than that of Spain (2983.2), Italy (2250.8), Germany (1241.5), France (1151.6), U.S. (1102.8), U.K. (831.5), Singapore (259.8), and South Korea (200.5). The compliance of face mask usage by HKSAR general public was 96.6% (range: 95.7% to 97.2%). We observed 11 COVID-19 clusters in recreational ‘mask-off’ settings compared to only 3 in workplace ‘mask-on’ settings (p = 0.036 by Chi square test of goodness-of-fit).


      Community-wide mask wearing may contribute to the control of COVID-19 by reducing the amount of emission of infected saliva and respiratory droplets from individuals with subclinical or mild COVID-19.


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        • Chan J.F.
        • Kok K.H.
        • Zhu Z.
        • Chu H.
        • To K.K.
        • Yuan S.
        • et al.
        Genomic characterization of the 2019 novel human-pathogenic coronavirus isolated from a patient with atypical pneumonia after visiting Wuhan.
        Emerg Microbes Infect. 2020; 9: 221-236
      1. WHO Director-General's opening remarks at the media briefing on COVID-19 - 11 March 2020. 2020. 10 April 2020.

      2. The Centre for health protection closely monitors cluster of pneumonia cases on Mainland. Press release of the department of health, Hong Kong Special Administrative Region. 2019. 10 April 2020.

      3. Coronavirus disease 2019 (COVID-19). Situation Report – 79. World Health Organization. 2020. 10 April 2020.

        • Cheng V.C.C.
        • Wong S.C.
        • To K.K.W.
        • Ho P.L.
        • Yuen K.Y.
        Preparedness and proactive infection control measures against the emerging novel coronavirus in China.
        J Hosp Infect. 2020; 104: 254-255
        • Cheng V.C.C.
        • Wong S.C.
        • Chen J.H.K.
        • Yip C.C.Y.
        • Chuang V.W.M.
        • Tsang O.T.Y.
        • et al.
        Escalating infection control response to the rapidly evolving epidemiology of the coronavirus disease 2019 (COVID-19) due to SARS-CoV-2 in Hong Kong.
        Infect Control Hosp Epidemiol. 2020; : 1-6
        • Cheng V.C.
        • Lau S.K.
        • Woo P.C.
        • Yuen K.Y.
        Severe acute respiratory syndrome coronavirus as an agent of emerging and reemerging infection.
        Clin Microbiol Rev. 2007; 20: 660-694
        • Cheng V.C.
        • To K.K.
        • Tse H.
        • Hung I.F.
        • Yuen K.Y.
        Two years after pandemic influenza A/2009/H1N1: what have we learned?.
        Clin Microbiol Rev. 2012; 25: 223-263
        • Chan J.F.
        • Yuan S.
        • Kok K.H.
        • To K.K.
        • Chu H.
        • Yang J.
        • et al.
        A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: a study of a family cluster.
        Lancet. 2020; 395: 514-523
        • Chu H.
        • Chan J.F.
        • Wang Y.
        • Yuen T.T.
        • Chai Y.
        • Hou Y.
        • et al.
        Comparative replication and immune activation profiles of SARS-CoV-2 and SARS-CoV in human lungs: an ex vivo study with implications for the pathogenesis of COVID-19.
        Clin Infect Dis. 2020;
        • Chan J.F.
        • Yip C.C.
        • To K.K.
        • Tang T.H.
        • Wong S.C.
        • Leung K.H.
        • et al.
        Improved molecular diagnosis of COVID-19 by the novel, highly sensitive and specific COVID-19-RdRp/Hel real-time reverse transcription-polymerase chain reaction assay validated in vitro and with clinical specimens.
        J Clin Microbiol. 2020;
        • MacIntyre C.R.
        • Cauchemez S.
        • Dwyer D.E.
        • Seale H.
        • Cheung P.
        • Browne G.
        • et al.
        Face mask use and control of respiratory virus transmission in households.
        Emerg Infect Dis. 2009; 15: 233-241
        • Cowling B.J.
        • Chan K.H.
        • Fang V.J.
        • Cheng C.K.
        • Fung R.O.
        • Wai W.
        • et al.
        Facemasks and hand hygiene to prevent influenza transmission in households: a cluster randomized trial.
        Ann Intern Med. 2009; 151: 437-446
        • Lo J.Y.
        • Tsang T.H.
        • Leung Y.H.
        • Yeung E.Y.
        • Wu T.
        • Lim W.W.
        Respiratory infections during SARS outbreak, Hong Kong, 2003.
        Emerg Infect Dis. 2005; 11: 1738-1741
        • Wu J.
        • Xu F.
        • Zhou W.
        • Feikin D.R.
        • Lin C.Y.
        • He X.
        • et al.
        Risk factors for SARS among persons without known contact with SARS patients, Beijing, China.
        Emerg Infect Dis. 2004; 10: 210-216
        • To K.K.
        • Tsang O.T.
        • Chik-Yan Yip C.
        • Chan K.H.
        • Wu T.C.
        • Chan J.M.C.
        • et al.
        Consistent detection of 2019 novel coronavirus in saliva.
        Clin Infect Dis. 2020;
        • To K.K.
        • Tsang O.T.
        • Leung W.S.
        • Tam A.R.
        • Wu T.C.
        • Lung D.C.
        • et al.
        Temporal profiles of viral load in posterior oropharyngeal saliva samples and serum antibody responses during infection by SARS-CoV-2: an observational cohort study.
        Lancet Infect Dis. 2020;
      4. Hong Kong in figures. Census and Statistics Department. Hong Kong Special Administrative Region. 2020. Accessed 24 April 2020.

        • Gursel M.
        • Gursel I.
        Is global BCG vaccination coverage relevant to the progression of SARS-CoV-2 pandemic?.
        Med Hypothesis. 2020;
      5. Updates on COVID-19 (Coronavirus disease 2019) local situation. Ministry of Health, Singapore. 2020. Accessed 12 April 2020.

        • Chan K.H.
        • Yuen K.Y.
        COVID-19 epidemic: disentangling the re-emerging controversy about medical facemasks from an epidemiological perspective.
        Int J Epidemiol. 2020;
        • Feng S.
        • Shen C.
        • Xia N.
        • Song W.
        • Fan M.
        • Cowling B.J.
        Rational use of face masks in the COVID-19 pandemic.
        Lancet Respir Med. 2020;
      6. World Health Organization. Advice on the use of masks in the context of COVID-19. Interim guidance (6 April 2020). 10 April 2020.

      7. Using face masks in the community - Reducing COVID-19 transmission from potentially asymptomatic or pre-symptomatic people through the use of face masks. 2020. Accessed 10 April 2020.

      8. Centers for Disease Control and Prevention. Coronavirus disease 2019 (COVID-19). Recommendation regarding the use of cloth face coverings, especially in areas of significant community-based transmission. 2020. 10 April 2020

        • Zou L.
        • Ruan F.
        • Huang M.
        • Liang L.
        • Huang H.
        • Hong Z.
        • et al.
        SARS-CoV-2 viral load in upper respiratory specimens of infected patients.
        N Engl J Med. 2020; 382: 1177-1179
        • Hui D.S.
        • Chow B.K.
        • Chu L.
        • Ng S.S.
        • Lee N.
        • Gin T.
        • et al.
        Exhaled air dispersion during coughing with and without wearing a surgical or N95 mask.
        PLoS ONE. 2012; 7: e50845
        • Chan A.L.Y.
        • Leung C.C.
        • Lam T.H.
        • Cheng K.K.
        To wear or not to wear: WHO’s confusing guidance on masks in the covid-19 pandemic.
        BMJ opinion. 2020;
        • Hendley J.O.
        • Wenzel R.P.
        • Gwaltney Jr., J.M.
        Transmission of rhinovirus colds by self-inoculation.
        N Engl J Med. 1973; 288: 1361-1364
        • Cheng V.C.
        • Tai J.W.
        • Li W.S.
        • Chau P.H.
        • So S.Y.
        • Wong L.M.
        • et al.
        Implementation of directly observed patient hand hygiene for hospitalized patients by hand hygiene ambassadors in Hong Kong.
        Am J Infect Control. 2016; 44: 621-624
        • Cheng V.C.C.
        • Wong S.C.
        • Wong S.C.Y.
        • Yuen K.Y.
        Directly observed hand hygiene - from healthcare workers to patients.
        J Hosp Infect. 2019; 101: 380-382
        • Cheng V.C.C.
        • Chen H.
        • Wong S.C.
        • Chen J.H.K.
        • Ng W.C.
        • So S.Y.C.
        • et al.
        Role of hand hygiene ambassador and implementation of directly observed hand hygiene among residents in residential care homes for the elderly in Hong Kong.
        Infect Control Hosp Epidemiol. 2018; 39: 571-577
        • Wong V.W.
        • Cowling B.J.
        • Aiello A.E.
        Hand hygiene and risk of influenza virus infections in the community: a systematic review and meta-analysis.
        Epidemiol Infect. 2014; 142: 922-932
        • Greenhalgh T.
        • Schmid M.B.
        • Czypionka T.
        • Bassler D.
        • Gruer L.
        Face masks for the public during the covid-19 crisis.
        BMJ. 2020; 369: m1435
        • Chan J.F.
        • Zhang A.J.
        • Yuan S.
        • Poon V.K.
        • Chan C.C.
        • Lee A.C.
        • et al.
        Simulation of the clinical and pathological manifestations of coronavirus disease 2019 (COVID-19) in golden Syrian hamster model: implications for disease pathogenesis and transmissibility.
        Clin Infect Dis. 2020;
      9. South Korea takes new measures to have enough face masks domestically amid coronavirus. abc News. 2020. 16 April 2020.

      10. Mandatory for all in Singapore to wear mask when out, except for kids under 2 and those doing strenuous exercise. Straits Times. 2020. 16 April 2020.