Advertisement

Uptake and effectiveness of facemask against respiratory infections at mass gatherings: a systematic review

  • Osamah Barasheed
    Correspondence
    Corresponding author. Tel.: +966 503 362 068.
    Affiliations
    Research Center, King Abdullah Medical City (KAMC), Makkah, P.O. Box: 57657, Saudi Arabia

    National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases (NCIRS), The Children's Hospital at Westmead, NSW, Australia
    Search for articles by this author
  • Mohammad Alfelali
    Affiliations
    National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases (NCIRS), The Children's Hospital at Westmead, NSW, Australia

    Department of Family and Community Medicine, Faculty of Medicine, King Abdulaziz University, Rabigh, Saudi Arabia
    Search for articles by this author
  • Sami Mushta
    Affiliations
    Ministry of Health, Abha, Saudi Arabia
    Search for articles by this author
  • Hamid Bokhary
    Affiliations
    Umm Al-Qura University Medical Center, Umm Al-Qura University, Makkah, Saudi Arabia
    Search for articles by this author
  • Jassir Alshehri
    Affiliations
    Research Center, King Abdullah Medical City (KAMC), Makkah, P.O. Box: 57657, Saudi Arabia
    Search for articles by this author
  • Ammar A. Attar
    Affiliations
    Department of Laboratory Medicine, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia

    Science and technology Unit, General Presidency for the Holy Mosque & Prophet Holy Mosque affairs, Makkah, Saudi Arabia

    Department of Innovation & Corporate Integration, King Abdullah Medical City (KAMC), Makkah, Saudi Arabia
    Search for articles by this author
  • Robert Booy
    Affiliations
    National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases (NCIRS), The Children's Hospital at Westmead, NSW, Australia

    Marie Bashir Institute for Infectious Diseases and Biosecurity, School of Biological Sciences and Sydney Medical School, The University of Sydney, Australia
    Search for articles by this author
  • Harunor Rashid
    Affiliations
    National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases (NCIRS), The Children's Hospital at Westmead, NSW, Australia

    Marie Bashir Institute for Infectious Diseases and Biosecurity, School of Biological Sciences and Sydney Medical School, The University of Sydney, Australia
    Search for articles by this author
Open AccessPublished:March 29, 2016DOI:https://doi.org/10.1016/j.ijid.2016.03.023

      Highlights

      • Approximately half of the attendees of mass gatherings use facemask
      • Facemask seems to be effective against respiratory infections at Hajj
      • Effectiveness of facemask against specific respiratory infections is not proven

      Abstract

      Objectives

      The risk of acquisition and transmission of respiratory infections is high among attendees of mass gatherings (MGs). Currently used interventions have limitations yet the role of facemask in preventing those infections at MG has not been systematically reviewed. We have conducted a systematic review to synthesise evidence about the uptake and effectiveness of facemask against respiratory infections in MGs.

      Methods

      A comprehensive literature search was conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines using major electronic databases such as, Medline, EMBASE, SCOPUS and CINAHL.

      Results

      Of 25 studies included, the pooled sample size was 12710 participants from 55 countries aged 11 to 89 years, 37% were female. The overall uptake of facemask ranged from 0.02% to 92.8% with an average of about 50%. Only 13 studies examined the effectiveness of facemask, and their pooled estimate revealed significant protectiveness against respiratory infections (relative risk [RR] = 0.89, 95% CI: 0.84-0.94, p < 0.01), but the study end points varied widely.

      Conclusion

      A modest proportion of attendees of MGs use facemask, the practice is more widespread among health care workers. Facemask use seems to be beneficial against certain respiratory infections at MGs but its effectiveness against specific infection remains unproven.

      Keywords

      1. Introduction

      The risk of acquisition and transmission of respiratory infections amplifies at mass gatherings (MGs) straining healthcare of the host country. For instance, in Hajj, one of the largest annual MG events in the world, more than 2 million people attend each year in Makkah, and over 90% suffer from at least one respiratory symptom, the risk of viral respiratory infections increases several folds and more severe respiratory infections such as pneumonia are the leading causes of hospital admission.
      • Benkouiten S.
      • Charrel R.
      • Belhouchat K.
      • Drali T.
      • Salez N.
      • Nougairede A.
      • et al.
      Circulation of respiratory viruses among pilgrims during the 2012 Hajj pilgrimage.
      • Benkouiten S.
      • Charrel R.
      • Belhouchat K.
      • Drali T.
      • Nougairede A.
      • Salez N.
      • et al.
      Respiratory viruses and bacteria among pilgrims during the 2013 Hajj.
      • Madani T.A.
      • Ghabrah T.M.
      • Al-Hedaithy M.A.
      • Alhazmi M.A.
      • Alazraqi T.A.
      • Albarrak A.M.
      • et al.
      Causes of hospitalization of pilgrims in the Hajj season of the Islamic year 1423 (2003).
      Likewise, a number of influenza outbreaks were reported during the World Youth Day 2008, a large catholic gathering in Sydney.
      • Blyth C.C.
      • Foo H.
      • van Hal S.J.
      • Hurt A.C.
      • Barr I.G.
      • McPhie K.
      • et al.
      Influenza outbreaks during World Youth Day 2008 mass gathering.
      MGs are also linked to globalisation of various infections. For instance, the Iztapalapa Play Passion, a religious festival in Mexico, was believed to spark the outbreak of swine flu leading to its accelerated dissemination across the world.
      • Zepeda-Lopez H.M.
      • Perea-Araujo L.
      • Miliar-Garcia A.
      • Dominguez-Lopez A.
      • Xoconostle-Cazarez B.
      • Lara-Padilla E.
      • et al.
      Inside the outbreak of the 2009 influenza A (H1N1)v virus in Mexico.
      Therefore, international public health agencies, including World Health Organization (WHO), have issued guidelines on mass gathering preparedness to minimise the possible risks.
      • Organization W.H.
      Communicable disease alert and response for mass gatherings: key considerations.
      From a public health perspective, one of the key concerns is to prevent global spread of respiratory infections during MGs. Interventions like vaccinations against viral and bacterial respiratory infections, anti-influenza prophylaxis and hand hygiene are considered as preventive measures but the measures have limitations. For instance, vaccinations against respiratory infections, such as influenza, are recommended for travellers to MGs such as Hajj,

      Health conditions for travellers to Saudi Arabia for the pilgrimage to Mecca (Hajj), 2014. Wkly Epidemiol Rec 2014; 89:357-60.

      and even though a recent systematic review generally supports its effectiveness against laboratory-confirmed influenza at Hajj,
      • Alqahtani A.S.
      • Rashid H.
      • Heywood A.E.
      Vaccinations against respiratory tract infections at Hajj.
      frequent mismatch between vaccine strains and circulating strains is an important concern.
      • Aleflali M.
      • Khandaker G.
      • Booy R.
      • Rashid H.
      Mismatching between circulating strains and vaccine strains of influenza: Effect on Hajj pilgrims from both hemispheres.
      Soaring antiviral resistance against both adamantanes and neuraminidase inhibitors is an issue that limits their widespread use in MGs.
      • Blyth C.C.
      • Foo H.
      • van Hal S.J.
      • Hurt A.C.
      • Barr I.G.
      • McPhie K.
      • et al.
      Influenza outbreaks during World Youth Day 2008 mass gathering.
      • Dixit R.
      • Khandaker G.
      • Ilgoutz S.
      • Rashid H.
      • Booy R.
      Emergence of oseltamivir resistance: control and management of influenza before, during and after the pandemic.
      Similarly, while hand hygiene has been recommended as a protective measure for attendees of MGs, its effectiveness is not fully evaluated in a mass gathering setting and the efficacy is debatable.
      • Benkouiten S.
      • Brouqui P.
      • Gautret P.
      Non-pharmaceutical interventions for the prevention of respiratory tract infections during Hajj pilgrimage.
      Therefore, the role of another protective measure, facemask, should be explored in the prevention of respiratory infections.
      • Haworth E.
      • Barasheed O.
      • Memish Z.A.
      • Rashid H.
      • Booy R.
      Prevention of influenza at Hajj: applications for mass gatherings.
      Facemask is believed to have a protective role in preventing nosocomial infections since the time of Spanish influenza.
      • Hobday R.A.
      • Cason J.W.
      The open-air treatment of pandemic influenza.
      Several studies have assessed the usefulness of facemask in household, community and healthcare settings, the findings of which have been summarised in a few reviews.
      • Bin-Reza F.
      • Lopez Chavarrias V.
      • Nicoll A.
      • Chamberland M.E.
      The use of masks and respirators to prevent transmission of influenza: a systematic review of the scientific evidence.
      • Rashid H.
      • Booy R.
      • Heron L.
      • Memish Z.A.
      • Nguyen-Van-Tam J.
      • Barasheed O.
      • et al.
      Unmasking masks in Makkah: preventing influenza at Hajj.
      • Sim S.W.
      • Moey K.S.
      • Tan N.C.
      The use of facemasks to prevent respiratory infection: a literature review in the context of the Health Belief Model.
      Noticeable disparities of facemask effectiveness between these studies were observed. Studies conducted in community or health care settings found facemasks to be generally effective against influenza-like illness (ILI) or even against severe acute respiratory syndrome (SARS) but its effectiveness against respiratory infections at MGs remains unknown.
      • Rashid H.
      • Booy R.
      • Heron L.
      • Memish Z.A.
      • Nguyen-Van-Tam J.
      • Barasheed O.
      • et al.
      Unmasking masks in Makkah: preventing influenza at Hajj.
      • Jefferson T.
      • Foxlee R.
      • Del Mar C.
      • Dooley L.
      • Ferroni E.
      • Hewak B.
      • et al.
      Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review.
      A review of non-pharmaceutical interventions against respiratory tract infections among Hajj pilgrims presented data on the uptake of facemask and acknowledged that compliance was generally poor, but did not evaluate its effectiveness during Hajj.
      • Benkouiten S.
      • Brouqui P.
      • Gautret P.
      Non-pharmaceutical interventions for the prevention of respiratory tract infections during Hajj pilgrimage.
      Subsequently, further data on the uptake and effectiveness have become available, especially from a pilot randomised controlled trial (RCT).
      • Barasheed O.
      • Almasri N.
      • Badahdah A.-M.
      • Heron L.
      • Taylor J.
      • McPhee K.
      • et al.
      Pilot randomised controlled trial to test effectiveness of facemasks in preventing influenza-like illness transmission among Australian hajj pilgrims in 2011.
      The aim of this systematic review is to explore the uptake and effectiveness of facemask against respiratory infections in MGs.

      2. Methods

      Studies were identified through searching electronic databases including; Medline (PubMed and Ovid), EMBASE, SCOPUS and CINAHL from database inception to February 8, 2016. We used a combination of MeSH terms and text words including: ‘crowding’ OR ‘mass gathering’ OR ‘large event’ OR ‘group assembly’ OR ‘holiday’ OR ‘travel’ OR ‘sport’ OR ‘Olympic’ OR ‘FIFA’ OR ‘festival’ OR ‘Hajj’ (also alternative spelling ‘Hadj’ or ‘Haj’) OR ‘pilgrimage’ AND ‘mask’ OR ‘facemask’ OR ‘surgical mask’ OR ‘medical mask’ OR ‘simple mask’ AND ‘infection’ OR ‘respiratory tract diseases’ OR ‘disease outbreaks’ OR ‘infectious disease’ OR ‘respiratory tract infections’ OR ‘influenza’ OR ‘pneumonia’. Additionally, an online search of pertinent epidemiology journals, including those not indexed in the mentioned databases (e.g. Saudi Epidemiology Bulletin) was carried out through free hand Google engine search. Finally, manual search was performed reviewing reference lists of included studies to identify additional potentially relevant studies. The search result was presented according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines (Figure 1).
      • Moher D.
      • Liberati A.
      • Tetzlaff J.
      • Altman D.G.
      Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement.
      In the first phase, three authors (OB, SM and HB) identified the potential titles, and sifted the titles and abstracts against the inclusion criteria. Titles of all studies published in English language and reported the use or effectiveness of facemask against respiratory infections in MGs were preliminarily included. Studies that dealt with attendees of MGs of any age, gender and country were considered for inclusion. At the end of the screening phase, full texts of potentially relevant studies were retrieved for detailed study. Finally studies that met the inclusion criteria were included for data synthesis. Duplicates were excluded.
      Five authors (OB, MA, HB, SM and JA) independently extracted the data from each study into a data extraction sheet which was divided in two sections, ‘facemask uptake’ and ‘facemask effectiveness’ and five authors subsequently cross-checked the entries (OB, AA, HB, SM and JA),while a sixth author (HR) arbitrated when a discrepancy occurred. The following data were abstracted in each extraction sheet: study design, year of conducting the study, sample size, country of origin, age, gender, diagnostic method used, definitions of study end point, and history of participants’ chronic diseases, if available.
      The quality of the included studies were categorised according to a modified ranking criteria based on Oxford Evidence Based Medicine (http://www.cebm.net/) into groups (e.g., A, B, C, D) where A was for RCTs of adequate sample size, B for observational studies of adequate sample size with good quality or pilot RCTs or non-randomised trial, C for observational studies of inadequate sample size or of poor quality, and D for cases series, such as focus groups or qualitative surveys.

      3. Results

      3.1 General description

      The search results are summarised in Figure 1. Briefly, of 567 abstracts and titles scanned ultimately 25 studies were included. All examined facemask uptake; of them, 13 studies also examined the effectiveness of facemask. The studies were conducted between 1999 and 2014 involving participants from 55 countries. Almost all the included studies involved Hajj pilgrims or other attendees of Hajj pilgrimage such as health care workers (HCWs) at Hajj. Four (out of 25) studies purely focused on the use of facemask against respiratory infections in MGs,
      • Barasheed O.
      • Almasri N.
      • Badahdah A.-M.
      • Heron L.
      • Taylor J.
      • McPhee K.
      • et al.
      Pilot randomised controlled trial to test effectiveness of facemasks in preventing influenza-like illness transmission among Australian hajj pilgrims in 2011.
      • Abdin E.Z.
      • Choudhry A.J.
      • Al-Naji A.
      Effect of use of face mask on Hajj-related respiratory infection among Hajjis from Riyadh - a health promotion intervention study.
      • Elachola H.
      • Assiri A.M.
      • Memish Z.A.
      Mass gathering-related mask use during 2009 pandemic influenza A (H1N1) and Middle East respiratory syndrome coronavirus.

      Zein U. The role of using masks to reduce acute upper respiratory tract infection in pilgrims. Abstract No. 7. 4th Asia Pacific travel health conference, Shanghai, PR China; October; 2002, p. e23.

      the other 21 studies included facemasks as a part of other intervention measures, or in the context of another research question.
      The study sample sizes varied widely ranging from 10 to 1717 participants. The included studies contained the pooled data of 12710 participants aged between 11 and 89 years (mean age ranged from 33.5 to 61.7 years in individual studies). About 37% of the pooled samples were females, in individual studies the proportion of females ranged from 10% to 63%. Excluding three studies, which involved HCWs deployed at Hajj,
      • Ahmed G.Y.
      • Balkhy H.H.
      • Bafaqeer S.
      • Al-Jasir B.
      • Althaqafi A.
      Acceptance and Adverse Effects of H1N1 Vaccinations Among a Cohort of National Guard Health Care Workers during the 2009 Hajj Season.
      • Al-Asmary S.
      • Al-Shehri A.S.
      • Abou-Zeid A.
      • Abdel-Fattah M.
      • Hifnawy T.
      • El-Said T.
      Acute respiratory tract infections among Hajj medical mission personnel, Saudi Arabia.
      • Memish Z.A.
      • Assiri A.M.
      • Alshehri M.
      • Hussain R.
      • Alomar I.
      The prevalance of respiratory viruses among healthcare workers serving pilgrims in Makkah during the 2009 influenza A (H1N1) pandemic.
      all other included studies involved Hajj pilgrims. The origin of the participants varied depending on the study, seven studies included multinational participants, while the other 18 were exclusive to participants from a single country of origin; seven out of 18 (38.9%) were from Saudi Arabia,
      • Abdin E.Z.
      • Choudhry A.J.
      • Al-Naji A.
      Effect of use of face mask on Hajj-related respiratory infection among Hajjis from Riyadh - a health promotion intervention study.
      • Ahmed G.Y.
      • Balkhy H.H.
      • Bafaqeer S.
      • Al-Jasir B.
      • Althaqafi A.
      Acceptance and Adverse Effects of H1N1 Vaccinations Among a Cohort of National Guard Health Care Workers during the 2009 Hajj Season.
      • Al-Asmary S.
      • Al-Shehri A.S.
      • Abou-Zeid A.
      • Abdel-Fattah M.
      • Hifnawy T.
      • El-Said T.
      Acute respiratory tract infections among Hajj medical mission personnel, Saudi Arabia.
      • Memish Z.A.
      • Assiri A.M.
      • Alshehri M.
      • Hussain R.
      • Alomar I.
      The prevalance of respiratory viruses among healthcare workers serving pilgrims in Makkah during the 2009 influenza A (H1N1) pandemic.
      • Al-Jasser F.S.
      • Kabbash I.A.
      • Almazroa M.A.
      • Memish Z.A.
      Patterns of diseases and preventive measures among domestic hajjis from Central, Saudi Arabia.
      • Aljoudi A.
      • Nooh R.
      • Jamil A.
      Effect of health education advice on Saudi Hajjis, Hajj 1423 H (2003 G).
      • Choudhry A.J.
      • Al-Mudaimegh K.S.
      • Turkistani A.M.
      • Al-Hamdan N.A.
      Hajj-associated acute respiratory infection among hajjis from Riyadh.
      According to study types 11 out of 25 were cohort studies,
      • Benkouiten S.
      • Charrel R.
      • Belhouchat K.
      • Drali T.
      • Salez N.
      • Nougairede A.
      • et al.
      Circulation of respiratory viruses among pilgrims during the 2012 Hajj pilgrimage.
      • Benkouiten S.
      • Charrel R.
      • Belhouchat K.
      • Drali T.
      • Nougairede A.
      • Salez N.
      • et al.
      Respiratory viruses and bacteria among pilgrims during the 2013 Hajj.

      Zein U. The role of using masks to reduce acute upper respiratory tract infection in pilgrims. Abstract No. 7. 4th Asia Pacific travel health conference, Shanghai, PR China; October; 2002, p. e23.

      • Ahmed G.Y.
      • Balkhy H.H.
      • Bafaqeer S.
      • Al-Jasir B.
      • Althaqafi A.
      Acceptance and Adverse Effects of H1N1 Vaccinations Among a Cohort of National Guard Health Care Workers during the 2009 Hajj Season.
      • Al-Asmary S.
      • Al-Shehri A.S.
      • Abou-Zeid A.
      • Abdel-Fattah M.
      • Hifnawy T.
      • El-Said T.
      Acute respiratory tract infections among Hajj medical mission personnel, Saudi Arabia.
      • Choudhry A.J.
      • Al-Mudaimegh K.S.
      • Turkistani A.M.
      • Al-Hamdan N.A.
      Hajj-associated acute respiratory infection among hajjis from Riyadh.
      • Alqahtani A.S.
      • BinDhim N.F.
      • Tashani M.
      • Willaby H.W.
      • Wiley K.E.
      • Heywood A.E.
      • et al.
      Pilot use of a novel smartphone application to track traveller health behaviour and collect infectious disease data during a mass gathering: Hajj pilgrimage 2014.
      • Balaban V.
      • Stauffer W.M.
      • Hammad A.
      • Afgarshe M.
      • Abd-Alla M.
      • Ahmed Q.
      • et al.
      Protective practices and respiratory illness among US travelers to the 2009 Hajj.
      • Emamian M.H.
      • Hassani A.M.
      • Fateh M.
      Respiratory Tract Infections and its Preventive Measures among Hajj Pilgrims, 2010: A Nested Case Control Study.
      • Gautret P.
      • Benkouiten S.
      • Griffiths K.
      • Sridhar S.
      The inevitable Hajj cough: Surveillance data in French pilgrims, 2012-2014.
      • Gautret P.
      • Vu Hai V.
      • Sani S.
      • Doutchi M.
      • Parola P.
      • Brouqui P.
      Protective measures against acute respiratory symptoms in French pilgrims participating in the Hajj of 2009.
      another 11 cross-sectional studies,
      • Elachola H.
      • Assiri A.M.
      • Memish Z.A.
      Mass gathering-related mask use during 2009 pandemic influenza A (H1N1) and Middle East respiratory syndrome coronavirus.
      • Memish Z.A.
      • Assiri A.M.
      • Alshehri M.
      • Hussain R.
      • Alomar I.
      The prevalance of respiratory viruses among healthcare workers serving pilgrims in Makkah during the 2009 influenza A (H1N1) pandemic.
      • Al-Jasser F.S.
      • Kabbash I.A.
      • Almazroa M.A.
      • Memish Z.A.
      Patterns of diseases and preventive measures among domestic hajjis from Central, Saudi Arabia.
      • Aljoudi A.
      • Nooh R.
      • Jamil A.
      Effect of health education advice on Saudi Hajjis, Hajj 1423 H (2003 G).
      • Al-Maghderi Y.
      • Al-Joudi A.
      • Choudhry A.J.
      • Al-Rabeah A.M.
      • Ibrahim M.
      • Turkistani A.M.
      Behavioral Risk Factors for Disease during Hajj 1422 H, (2002 G).
      • Al-Shihry A.M.
      • Al-Khan A.A.
      • Mohammed A.G.
      Pre-Hajj Health related advice.
      • Al-Zahrani I.
      • Chaudhry A.
      • Alhamdan N.
      Sources of health education for international Arab pilgrims and the effect of this education on their practices towards health hazards in hajj, 1427 H (2006).
      • Deris Z.Z.
      • Hasan H.
      • Sulaiman S.A.
      • Wahab M.S.
      • Naing N.N.
      • Othman N.H.
      The prevalence of acute respiratory symptoms and role of protective measures among Malaysian hajj pilgrims.
      • Khamis N.K.
      Epidemiological pattern of diseases and risk behaviors of pilgrims attending mina hospitals, hajj 1427 h (2007 g).
      • Maslamani Y.
      • Choudhry A.J.
      Health related experiences among international pilgrims departing through King Abdul Aziz international airport, Jeddah, Saudi Arabia, Hajj 1431 H (2010).
      • Hashim S.
      • Ayub Z.N.
      • Mohamed Z.
      • Hasan H.
      • Harun A.
      • Ismail N.
      • et al.
      The prevalence and preventive measures of the respiratory illness among Malaysian pilgrims in 2013 hajj season.
      two trials (not necessarily RCTs)
      • Barasheed O.
      • Almasri N.
      • Badahdah A.-M.
      • Heron L.
      • Taylor J.
      • McPhee K.
      • et al.
      Pilot randomised controlled trial to test effectiveness of facemasks in preventing influenza-like illness transmission among Australian hajj pilgrims in 2011.
      • Abdin E.Z.
      • Choudhry A.J.
      • Al-Naji A.
      Effect of use of face mask on Hajj-related respiratory infection among Hajjis from Riyadh - a health promotion intervention study.
      and one case-series conducted as a qualitative study
      • Alqahtani A.S.
      • Sheikh M.
      • Wiley K.
      • Heywood A.E.
      Australian Hajj pilgrims’ infection control beliefs and practices: Insight with implications for public health approaches.
      (Table 1).
      Table 1Characteristics of included studies that examined facemask uptake among Hajj attendees in the last decade
      AuthorStudy yearStudy typeStudy populationGender female %Mean age (range) yearsChronic disease %Facemask uptake %Reason for non-complianceRanking
      Al-Shihry et al
      • Al-Shihry A.M.
      • Al-Khan A.A.
      • Mohammed A.G.
      Pre-Hajj Health related advice.
      1999Cross-sectional1707 international pilgrimsNRNRNR24NRD
      Al-Maghderi et al
      • Al-Maghderi Y.
      • Al-Joudi A.
      • Choudhry A.J.
      • Al-Rabeah A.M.
      • Ibrahim M.
      • Turkistani A.M.
      Behavioral Risk Factors for Disease during Hajj 1422 H, (2002 G).
      2002Cross-sectional1374 international pilgrims13.64313.233.2NRC
      Zein, U

      Zein U. The role of using masks to reduce acute upper respiratory tract infection in pilgrims. Abstract No. 7. 4th Asia Pacific travel health conference, Shanghai, PR China; October; 2002, p. e23.

      2002Cohort447 Indonesian pilgrims63.152.4 (40-64.8)40.948.4NRC
      Choudhry et al
      • Choudhry A.J.
      • Al-Mudaimegh K.S.
      • Turkistani A.M.
      • Al-Hamdan N.A.
      Hajj-associated acute respiratory infection among hajjis from Riyadh.
      2002Cohort1027 Saudi Arabia pilgrims2733.5 (21.8-45.2)8.153.6NRC
      Aljoudi et al
      • Aljoudi A.
      • Nooh R.
      • Jamil A.
      Effect of health education advice on Saudi Hajjis, Hajj 1423 H (2003 G).
      2003Cross-sectional451 Saudi Arabia pilgrims30.6NRNR35.3NRD
      Abdin et al
      • Abdin E.Z.
      • Choudhry A.J.
      • Al-Naji A.
      Effect of use of face mask on Hajj-related respiratory infection among Hajjis from Riyadh - a health promotion intervention study.
      2004Trial995 Saudi Arabia pilgrims4335.3 (21.6-49)2651.3NRC
      Al-Asmary et al
      • Al-Asmary S.
      • Al-Shehri A.S.
      • Abou-Zeid A.
      • Abdel-Fattah M.
      • Hifnawy T.
      • El-Said T.
      Acute respiratory tract infections among Hajj medical mission personnel, Saudi Arabia.
      2005Case control250 Saudi Arabia HCWs12.837 (28.3-45.7)NR92.8NRC
      Al-Zahrani et al
      • Al-Zahrani I.
      • Chaudhry A.
      • Alhamdan N.
      Sources of health education for international Arab pilgrims and the effect of this education on their practices towards health hazards in hajj, 1427 H (2006).
      2006Cross-sectional500 international pilgrims1043.5 (11-84)NR59.4NRC
      Khamis et al
      • Khamis N.K.
      Epidemiological pattern of diseases and risk behaviors of pilgrims attending mina hospitals, hajj 1427 h (2007 g).
      2007Cross-sectional248 international pilgrims54.440.1 (22.5-57.7)39.112.1NRC
      Deris et al
      • Deris Z.Z.
      • Hasan H.
      • Sulaiman S.A.
      • Wahab M.S.
      • Naing N.N.
      • Othman N.H.
      The prevalence of acute respiratory symptoms and role of protective measures among Malaysian hajj pilgrims.
      2007Cross-sectional387 Malaysian pilgrims43.950.4 (39.4-61.4)NR72.9NRC
      Elachola et al
      • Elachola H.
      • Assiri A.M.
      • Memish Z.A.
      Mass gathering-related mask use during 2009 pandemic influenza A (H1N1) and Middle East respiratory syndrome coronavirus.
      2009Cross-sectionalinternational photo frames23NRNR8.4NRD
      Balaban et al
      • Balaban V.
      • Stauffer W.M.
      • Hammad A.
      • Afgarshe M.
      • Abd-Alla M.
      • Ahmed Q.
      • et al.
      Protective practices and respiratory illness among US travelers to the 2009 Hajj.
      2009Cohort186 USA pilgrims50.548.9 (16-89)16.748.9NRC
      Al-Jasser et al
      • Al-Jasser F.S.
      • Kabbash I.A.
      • Almazroa M.A.
      • Memish Z.A.
      Patterns of diseases and preventive measures among domestic hajjis from Central, Saudi Arabia.
      2009Cross-sectional1507 Saudi Arabia pilgrims38.337.9 (21-83)18.456.5NRB
      Ahmed et al
      • Ahmed G.Y.
      • Balkhy H.H.
      • Bafaqeer S.
      • Al-Jasir B.
      • Althaqafi A.
      Acceptance and Adverse Effects of H1N1 Vaccinations Among a Cohort of National Guard Health Care Workers during the 2009 Hajj Season.
      2009Cohort126 Saudi Arabia HCWs20.638.7 (28.9-48.5)-50NRC
      Memish et al
      • Memish Z.A.
      • Assiri A.M.
      • Alshehri M.
      • Hussain R.
      • Alomar I.
      The prevalance of respiratory viruses among healthcare workers serving pilgrims in Makkah during the 2009 influenza A (H1N1) pandemic.
      2009Cross-sectional104 Saudi Arabia HCWs1540.9 (23-59)1573.1NRC
      Gautret et al
      • Gautret P.
      • Vu Hai V.
      • Sani S.
      • Doutchi M.
      • Parola P.
      • Brouqui P.
      Protective measures against acute respiratory symptoms in French pilgrims participating in the Hajj of 2009.
      2009Cohort274 French pilgrims47.758 (23-83)49.379.6NRC
      Maslamani et al
      • Maslamani Y.
      • Choudhry A.J.
      Health related experiences among international pilgrims departing through King Abdul Aziz international airport, Jeddah, Saudi Arabia, Hajj 1431 H (2010).
      2010Cross-sectional1717 international pilgrims36.346.2 (34.7-57.7)27.155.4NRC
      Emamian et al
      • Emamian M.H.
      • Hassani A.M.
      • Fateh M.
      Respiratory Tract Infections and its Preventive Measures among Hajj Pilgrims, 2010: A Nested Case Control Study.
      2010Cohort95 Iranian pilgrims42.1NR48.460NRD
      Barasheed et al
      • Barasheed O.
      • Almasri N.
      • Badahdah A.-M.
      • Heron L.
      • Taylor J.
      • McPhee K.
      • et al.
      Pilot randomised controlled trial to test effectiveness of facemasks in preventing influenza-like illness transmission among Australian hajj pilgrims in 2011.
      2011RCT164 Australian pilgrims56.744.1 (17-80)2240.9DiscomfortB
      Benkouiten et al
      • Benkouiten S.
      • Charrel R.
      • Belhouchat K.
      • Drali T.
      • Salez N.
      • Nougairede A.
      • et al.
      Circulation of respiratory viruses among pilgrims during the 2012 Hajj pilgrimage.
      2012Cohort137 French pilgrims61.759.3 (21-83)57.555.1NRC
      Elachola et al
      • Elachola H.
      • Assiri A.M.
      • Memish Z.A.
      Mass gathering-related mask use during 2009 pandemic influenza A (H1N1) and Middle East respiratory syndrome coronavirus.
      2013Cross-sectionalInternational pilgrims16NANA0.02NRD
      Benkouiten et al
      • Benkouiten S.
      • Charrel R.
      • Belhouchat K.
      • Drali T.
      • Nougairede A.
      • Salez N.
      • et al.
      Respiratory viruses and bacteria among pilgrims during the 2013 Hajj.
      2013Cohort129 French pilgrims59.761.7 (34-85)52.753.5NRC
      Hashim et al
      • Hashim S.
      • Ayub Z.N.
      • Mohamed Z.
      • Hasan H.
      • Harun A.
      • Ismail N.
      • et al.
      The prevalence and preventive measures of the respiratory illness among Malaysian pilgrims in 2013 hajj season.
      2013Cross-sectional468 Malaysian pilgrims43.852.5 (42.4- 62.7)5168.8NRC
      Alqahtani et al
      • Alqahtani A.S.
      • BinDhim N.F.
      • Tashani M.
      • Willaby H.W.
      • Wiley K.E.
      • Heywood A.E.
      • et al.
      Pilot use of a novel smartphone application to track traveller health behaviour and collect infectious disease data during a mass gathering: Hajj pilgrimage 2014.
      2014Cohort25 international pilgrims41.537.1 (21-61)3964Discomfort and breathing difficultiesD
      Alqahtani et al
      • Alqahtani A.S.
      • Sheikh M.
      • Wiley K.
      • Heywood A.E.
      Australian Hajj pilgrims’ infection control beliefs and practices: Insight with implications for public health approaches.
      2009-12Case series10 Australian pilgrims40NRNR40NRD
      Gautret et al
      • Gautret P.
      • Benkouiten S.
      • Griffiths K.
      • Sridhar S.
      The inevitable Hajj cough: Surveillance data in French pilgrims, 2012-2014.
      2012-14Cohort382 French pilgrims6260.6 (22-85)55.153.7NRC
      Pooled estimate1999-2014All studies12710 participants of 55 nations37.343.5 (11-89)-49.7--
      HCWs, health care workers; NA, not applicable; NR, not reported; RCT, randomised controlled trial; USA, United States of America.

      3.2 Uptake of facemask

      The median uptake of facemask in pooled sample was 53.5%. The lowest reported uptake was 0.02% by Elachola et al. among pilgrims in a unique study that involved quantification of facemasks through photo frames from surveillance camera during the Hajj in 2013, therefor it is considered as an outlier.
      • Elachola H.
      • Assiri A.M.
      • Memish Z.A.
      Mass gathering-related mask use during 2009 pandemic influenza A (H1N1) and Middle East respiratory syndrome coronavirus.
      The highest uptake was 92.8% observed by Al-Asmary et al. among health care workers during Hajj in 2005.
      • Al-Asmary S.
      • Al-Shehri A.S.
      • Abou-Zeid A.
      • Abdel-Fattah M.
      • Hifnawy T.
      • El-Said T.
      Acute respiratory tract infections among Hajj medical mission personnel, Saudi Arabia.
      Excluding these two studies (Elachola et al
      • Elachola H.
      • Assiri A.M.
      • Memish Z.A.
      Mass gathering-related mask use during 2009 pandemic influenza A (H1N1) and Middle East respiratory syndrome coronavirus.
      and Al-Asmary et al
      • Al-Asmary S.
      • Al-Shehri A.S.
      • Abou-Zeid A.
      • Abdel-Fattah M.
      • Hifnawy T.
      • El-Said T.
      Acute respiratory tract infections among Hajj medical mission personnel, Saudi Arabia.
      ), uptake rate among pilgrims has remained generally steady with gradual increase from 24% in 1999 to 64% in 2014 with minor fluctuations (Figure 2). Studies involving HCWs reported an uptake from 50% in 2009 to 92.8% in 2005. According to the pilgrims’ country of origin, Malaysian pilgrims were noticed to be most compliant to using facemasks (70.9%),
      • Deris Z.Z.
      • Hasan H.
      • Sulaiman S.A.
      • Wahab M.S.
      • Naing N.N.
      • Othman N.H.
      The prevalence of acute respiratory symptoms and role of protective measures among Malaysian hajj pilgrims.
      • Hashim S.
      • Ayub Z.N.
      • Mohamed Z.
      • Hasan H.
      • Harun A.
      • Ismail N.
      • et al.
      The prevalence and preventive measures of the respiratory illness among Malaysian pilgrims in 2013 hajj season.
      followed by French (60.5%)
      • Benkouiten S.
      • Charrel R.
      • Belhouchat K.
      • Drali T.
      • Salez N.
      • Nougairede A.
      • et al.
      Circulation of respiratory viruses among pilgrims during the 2012 Hajj pilgrimage.
      • Benkouiten S.
      • Charrel R.
      • Belhouchat K.
      • Drali T.
      • Nougairede A.
      • Salez N.
      • et al.
      Respiratory viruses and bacteria among pilgrims during the 2013 Hajj.
      • Gautret P.
      • Benkouiten S.
      • Griffiths K.
      • Sridhar S.
      The inevitable Hajj cough: Surveillance data in French pilgrims, 2012-2014.
      • Gautret P.
      • Vu Hai V.
      • Sani S.
      • Doutchi M.
      • Parola P.
      • Brouqui P.
      Protective measures against acute respiratory symptoms in French pilgrims participating in the Hajj of 2009.
      and Iranians (60%)
      • Emamian M.H.
      • Hassani A.M.
      • Fateh M.
      Respiratory Tract Infections and its Preventive Measures among Hajj Pilgrims, 2010: A Nested Case Control Study.
      (Table 1).
      Figure thumbnail gr2
      Figure 2Facemask uptake rate among Hajj pilgrims from 1999 to 2014.
      Only three studies, all involving Australian pilgrims, evaluated the reasons of compliance (or non-compliance) of using facemask during Hajj.
      • Barasheed O.
      • Almasri N.
      • Badahdah A.-M.
      • Heron L.
      • Taylor J.
      • McPhee K.
      • et al.
      Pilot randomised controlled trial to test effectiveness of facemasks in preventing influenza-like illness transmission among Australian hajj pilgrims in 2011.
      • Alqahtani A.S.
      • BinDhim N.F.
      • Tashani M.
      • Willaby H.W.
      • Wiley K.E.
      • Heywood A.E.
      • et al.
      Pilot use of a novel smartphone application to track traveller health behaviour and collect infectious disease data during a mass gathering: Hajj pilgrimage 2014.
      • Alqahtani A.S.
      • Sheikh M.
      • Wiley K.
      • Heywood A.E.
      Australian Hajj pilgrims’ infection control beliefs and practices: Insight with implications for public health approaches.
      The most reported reasons for wearing facemask were to avoid transmission of infectious organisms and protection from air pollution.
      • Alqahtani A.S.
      • BinDhim N.F.
      • Tashani M.
      • Willaby H.W.
      • Wiley K.E.
      • Heywood A.E.
      • et al.
      Pilot use of a novel smartphone application to track traveller health behaviour and collect infectious disease data during a mass gathering: Hajj pilgrimage 2014.
      However, discomfort and difficulty in breathing were the most reported reasons for not wearing facemask.
      • Barasheed O.
      • Almasri N.
      • Badahdah A.-M.
      • Heron L.
      • Taylor J.
      • McPhee K.
      • et al.
      Pilot randomised controlled trial to test effectiveness of facemasks in preventing influenza-like illness transmission among Australian hajj pilgrims in 2011.
      • Alqahtani A.S.
      • Sheikh M.
      • Wiley K.
      • Heywood A.E.
      Australian Hajj pilgrims’ infection control beliefs and practices: Insight with implications for public health approaches.

      3.3 Effectiveness of facemask

      Thirteen studies investigated the effectiveness/efficacy of facemask against respiratory infections, but the endpoints varied very widely. Most of these studies (9 out of 13) used a combination of respiratory symptoms (syndromic) as endpoints with varying definitions. For instance, acute respiratory infections (ARI) was used as an endpoint in three studies,
      • Abdin E.Z.
      • Choudhry A.J.
      • Al-Naji A.
      Effect of use of face mask on Hajj-related respiratory infection among Hajjis from Riyadh - a health promotion intervention study.
      • Al-Asmary S.
      • Al-Shehri A.S.
      • Abou-Zeid A.
      • Abdel-Fattah M.
      • Hifnawy T.
      • El-Said T.
      Acute respiratory tract infections among Hajj medical mission personnel, Saudi Arabia.
      • Choudhry A.J.
      • Al-Mudaimegh K.S.
      • Turkistani A.M.
      • Al-Hamdan N.A.
      Hajj-associated acute respiratory infection among hajjis from Riyadh.
      ILI in two,
      • Barasheed O.
      • Almasri N.
      • Badahdah A.-M.
      • Heron L.
      • Taylor J.
      • McPhee K.
      • et al.
      Pilot randomised controlled trial to test effectiveness of facemasks in preventing influenza-like illness transmission among Australian hajj pilgrims in 2011.
      • Deris Z.Z.
      • Hasan H.
      • Sulaiman S.A.
      • Wahab M.S.
      • Naing N.N.
      • Othman N.H.
      The prevalence of acute respiratory symptoms and role of protective measures among Malaysian hajj pilgrims.
      upper respiratory tract infection (URTI) in two,

      Zein U. The role of using masks to reduce acute upper respiratory tract infection in pilgrims. Abstract No. 7. 4th Asia Pacific travel health conference, Shanghai, PR China; October; 2002, p. e23.

      • Al-Jasser F.S.
      • Kabbash I.A.
      • Almazroa M.A.
      • Memish Z.A.
      Patterns of diseases and preventive measures among domestic hajjis from Central, Saudi Arabia.
      respiratory illness in two
      • Balaban V.
      • Stauffer W.M.
      • Hammad A.
      • Afgarshe M.
      • Abd-Alla M.
      • Ahmed Q.
      • et al.
      Protective practices and respiratory illness among US travelers to the 2009 Hajj.
      • Hashim S.
      • Ayub Z.N.
      • Mohamed Z.
      • Hasan H.
      • Harun A.
      • Ismail N.
      • et al.
      The prevalence and preventive measures of the respiratory illness among Malaysian pilgrims in 2013 hajj season.
      and respiratory tract infections in one.
      • Emamian M.H.
      • Hassani A.M.
      • Fateh M.
      Respiratory Tract Infections and its Preventive Measures among Hajj Pilgrims, 2010: A Nested Case Control Study.
      However a couple of studies used only one respiratory symptom as an endpoint: fever
      • Maslamani Y.
      • Choudhry A.J.
      Health related experiences among international pilgrims departing through King Abdul Aziz international airport, Jeddah, Saudi Arabia, Hajj 1431 H (2010).
      and cough.
      • Gautret P.
      • Benkouiten S.
      • Griffiths K.
      • Sridhar S.
      The inevitable Hajj cough: Surveillance data in French pilgrims, 2012-2014.
      Only one study established laboratory-proven viral infections
      • Memish Z.A.
      • Assiri A.M.
      • Alshehri M.
      • Hussain R.
      • Alomar I.
      The prevalance of respiratory viruses among healthcare workers serving pilgrims in Makkah during the 2009 influenza A (H1N1) pandemic.
      as an endpoint. Definitions for the endpoints are detailed in Table 2.
      Table 2Characteristics of included studies that examined facemask effectiveness against respiratory infections in Hajj
      AuthorStudy yearStudy typeSample sizeEnd points; definitionsRelative riskp-Value
      Zein, U

      Zein U. The role of using masks to reduce acute upper respiratory tract infection in pilgrims. Abstract No. 7. 4th Asia Pacific travel health conference, Shanghai, PR China; October; 2002, p. e23.

      2002Cohort446URTI; diagnosed by clinical symptom such as cough, fever, sore throat, hoarseness, cold, and by physical examination0.30< 0.01
      Choudhry et al
      • Choudhry A.J.
      • Al-Mudaimegh K.S.
      • Turkistani A.M.
      • Al-Hamdan N.A.
      Hajj-associated acute respiratory infection among hajjis from Riyadh.
      2002Cohort1027ARI; defined as the presence of one of the constitutional symptoms (fever, headache, myalgia) along with one of the local symptoms (running nose, sneezing, throat pain, cough with/without sputum, difficulty breathing)0.35< 0.01
      Abdin et al
      • Abdin E.Z.
      • Choudhry A.J.
      • Al-Naji A.
      Effect of use of face mask on Hajj-related respiratory infection among Hajjis from Riyadh - a health promotion intervention study.
      2004Trial994ARI; defined as the presence of one of the constitutional symptoms (fever, headache, myalgia) along with one of the local symptoms (running nose, sneezing, throat pain, cough with/without sputum, difficulty breathing)0.13< 0.01
      Al-Asmary et al
      • Al-Asmary S.
      • Al-Shehri A.S.
      • Abou-Zeid A.
      • Abdel-Fattah M.
      • Hifnawy T.
      • El-Said T.
      Acute respiratory tract infections among Hajj medical mission personnel, Saudi Arabia.
      2005Cohort250ARI; defined as the presence of one of the constitutional symptoms (fever, headache, myalgia) along with one of the local symptoms (running nose, sneezing, throat pain, cough with/without sputum, difficulty breathing)1.160.74
      Deris et al
      • Deris Z.Z.
      • Hasan H.
      • Sulaiman S.A.
      • Wahab M.S.
      • Naing N.N.
      • Othman N.H.
      The prevalence of acute respiratory symptoms and role of protective measures among Malaysian hajj pilgrims.
      2007Cross-sectional387ILI; defined as the triad of cough, subjective fever and sore throat1.330.07
      Balaban et al
      • Balaban V.
      • Stauffer W.M.
      • Hammad A.
      • Afgarshe M.
      • Abd-Alla M.
      • Ahmed Q.
      • et al.
      Protective practices and respiratory illness among US travelers to the 2009 Hajj.
      2009Cohort143Respiratory illness; defined as the presence of one or more of the following localising signs or symptoms: cough, congestion, sore throat, sneezing, or breathing problems1.250.34
      Al-Jasser et al
      • Al-Jasser F.S.
      • Kabbash I.A.
      • Almazroa M.A.
      • Memish Z.A.
      Patterns of diseases and preventive measures among domestic hajjis from Central, Saudi Arabia.
      2009Cross-sectional1507URTI; defined as one of the constitutional symptoms (fever, headache, myalgia) along with one of the local symptoms (running nose, sneezing, throat pain, cough with/without sputum, difficulty breathing)0.940.18
      Memish et al
      • Memish Z.A.
      • Assiri A.M.
      • Alshehri M.
      • Hussain R.
      • Alomar I.
      The prevalance of respiratory viruses among healthcare workers serving pilgrims in Makkah during the 2009 influenza A (H1N1) pandemic.
      2009Cross-sectional104Laboratory-proven viral infections by using multiplex PCR0.740.54
      Maslamani et al
      • Maslamani Y.
      • Choudhry A.J.
      Health related experiences among international pilgrims departing through King Abdul Aziz international airport, Jeddah, Saudi Arabia, Hajj 1431 H (2010).
      2010Cross-sectional1685Only fever1.33< 0.01
      Emamian et al
      • Emamian M.H.
      • Hassani A.M.
      • Fateh M.
      Respiratory Tract Infections and its Preventive Measures among Hajj Pilgrims, 2010: A Nested Case Control Study.
      2010Cohort95RTI; defined as all types of respiratory tract infections other than the common cold1.270.43
      Barasheed et al
      • Barasheed O.
      • Almasri N.
      • Badahdah A.-M.
      • Heron L.
      • Taylor J.
      • McPhee K.
      • et al.
      Pilot randomised controlled trial to test effectiveness of facemasks in preventing influenza-like illness transmission among Australian hajj pilgrims in 2011.
      2011RCT164ILI; defined as subjective (or proven) fever plus one respiratory symptom0.470.02
      Hashim et al
      • Hashim S.
      • Ayub Z.N.
      • Mohamed Z.
      • Hasan H.
      • Harun A.
      • Ismail N.
      • et al.
      The prevalence and preventive measures of the respiratory illness among Malaysian pilgrims in 2013 hajj season.
      2013Cross-sectional468Respiratory illness; defined as having ILI or at least one of the non-ILI respiratory symptoms1.040.22
      Gautret et al
      • Gautret P.
      • Benkouiten S.
      • Griffiths K.
      • Sridhar S.
      The inevitable Hajj cough: Surveillance data in French pilgrims, 2012-2014.
      2012-14Cohort382Only cough1.040.60
      Pooled estimate2002-14All studies7652-0.82< 0.01
      ARI, acute respiratory infection; ILI, influenza-like illness; PCR, polymerase chain reaction; RCT, randomised controlled trial; RTI, respiratory tract infection; URTI, upper respiratory tract infection.
      In regards to the effectiveness of facemask, four out of thirteen studies demonstrated significant effect against respiratory infections,
      • Barasheed O.
      • Almasri N.
      • Badahdah A.-M.
      • Heron L.
      • Taylor J.
      • McPhee K.
      • et al.
      Pilot randomised controlled trial to test effectiveness of facemasks in preventing influenza-like illness transmission among Australian hajj pilgrims in 2011.
      • Abdin E.Z.
      • Choudhry A.J.
      • Al-Naji A.
      Effect of use of face mask on Hajj-related respiratory infection among Hajjis from Riyadh - a health promotion intervention study.

      Zein U. The role of using masks to reduce acute upper respiratory tract infection in pilgrims. Abstract No. 7. 4th Asia Pacific travel health conference, Shanghai, PR China; October; 2002, p. e23.

      • Choudhry A.J.
      • Al-Mudaimegh K.S.
      • Turkistani A.M.
      • Al-Hamdan N.A.
      Hajj-associated acute respiratory infection among hajjis from Riyadh.
      two others showed some effect but did not reach statistical significance.
      • Memish Z.A.
      • Assiri A.M.
      • Alshehri M.
      • Hussain R.
      • Alomar I.
      The prevalance of respiratory viruses among healthcare workers serving pilgrims in Makkah during the 2009 influenza A (H1N1) pandemic.
      • Al-Jasser F.S.
      • Kabbash I.A.
      • Almazroa M.A.
      • Memish Z.A.
      Patterns of diseases and preventive measures among domestic hajjis from Central, Saudi Arabia.
      One study assessed its effectiveness against fever but ruled out its protectiveness,
      • Maslamani Y.
      • Choudhry A.J.
      Health related experiences among international pilgrims departing through King Abdul Aziz international airport, Jeddah, Saudi Arabia, Hajj 1431 H (2010).
      and the other six studies did not show effectiveness but results were not statistically significant.
      • Al-Asmary S.
      • Al-Shehri A.S.
      • Abou-Zeid A.
      • Abdel-Fattah M.
      • Hifnawy T.
      • El-Said T.
      Acute respiratory tract infections among Hajj medical mission personnel, Saudi Arabia.
      • Balaban V.
      • Stauffer W.M.
      • Hammad A.
      • Afgarshe M.
      • Abd-Alla M.
      • Ahmed Q.
      • et al.
      Protective practices and respiratory illness among US travelers to the 2009 Hajj.
      • Emamian M.H.
      • Hassani A.M.
      • Fateh M.
      Respiratory Tract Infections and its Preventive Measures among Hajj Pilgrims, 2010: A Nested Case Control Study.
      • Gautret P.
      • Benkouiten S.
      • Griffiths K.
      • Sridhar S.
      The inevitable Hajj cough: Surveillance data in French pilgrims, 2012-2014.
      • Deris Z.Z.
      • Hasan H.
      • Sulaiman S.A.
      • Wahab M.S.
      • Naing N.N.
      • Othman N.H.
      The prevalence of acute respiratory symptoms and role of protective measures among Malaysian hajj pilgrims.
      • Hashim S.
      • Ayub Z.N.
      • Mohamed Z.
      • Hasan H.
      • Harun A.
      • Ismail N.
      • et al.
      The prevalence and preventive measures of the respiratory illness among Malaysian pilgrims in 2013 hajj season.
      The pooled data from all studies revealed significant protectiveness of facemasks against respiratory infections in general at Hajj (relative risk [RR] = 0.89, 95% CI: 0.84-0.94, p < 0.01) (Table 2).
      According to the ranking system we used, most of the studies were of average quality (C) whereas two studies were ranked above average (B): a pilot RCT
      • Barasheed O.
      • Almasri N.
      • Badahdah A.-M.
      • Heron L.
      • Taylor J.
      • McPhee K.
      • et al.
      Pilot randomised controlled trial to test effectiveness of facemasks in preventing influenza-like illness transmission among Australian hajj pilgrims in 2011.
      and a large cross-sectional study,
      • Al-Jasser F.S.
      • Kabbash I.A.
      • Almazroa M.A.
      • Memish Z.A.
      Patterns of diseases and preventive measures among domestic hajjis from Central, Saudi Arabia.
      the other seven studies were of below average quality (D) either because of small sample size or poor study quality (Table 1).

      4. Discussion

      This systematic review shows that the use of facemask among the attendees of MGs remains essentially unchanged for decades although exceptionally in one study a very high uptake (about 93%)
      • Al-Asmary S.
      • Al-Shehri A.S.
      • Abou-Zeid A.
      • Abdel-Fattah M.
      • Hifnawy T.
      • El-Said T.
      Acute respiratory tract infections among Hajj medical mission personnel, Saudi Arabia.
      or a very low uptake rate (0.02%)
      • Elachola H.
      • Assiri A.M.
      • Memish Z.A.
      Mass gathering-related mask use during 2009 pandemic influenza A (H1N1) and Middle East respiratory syndrome coronavirus.
      has been reported but such variability can be explained by their unique study designs or population characteristics. The pooled data of this systematic review suggest that facemask is generally effective against respiratory infections at Hajj, however the endpoints varied widely.
      The uptake of facemask among HCWs deployed at Hajj was generally higher than that among ordinary Hajj pilgrims with average compliance among HCWs being 72% compared to 46% among pilgrims. This finding is similar to what have been found in other studies that examined the uptake of facemask in other settings such as health care and community settings. For instance, the uptake of facemask among HCWs in several studies ranged from 56.6% to 84.3% (average 70.7%).
      • Jacobs J.L.
      • Ohde S.
      • Takahashi O.
      • Tokuda Y.
      • Omata F.
      • Fukui T.
      Use of surgical face masks to reduce the incidence of the common cold among health care workers in Japan: a randomized controlled trial.
      • MacIntyre C.R.
      • Seale H.
      • Dung T.C.
      • Hien N.T.
      • Nga P.T.
      • Chughtai A.A.
      • et al.
      A cluster randomised trial of cloth masks compared with medical masks in healthcare workers.
      • MacIntyre C.R.
      • Wang Q.
      • Cauchemez S.
      • Seale H.
      • Dwyer D.E.
      • Yang P.
      • et al.
      A cluster randomized clinical trial comparing fit-tested and non-fit-tested N95 respirators to medical masks to prevent respiratory virus infection in health care workers.
      • MacIntyre C.R.
      • Wang Q.
      • Seale H.
      • Yang P.
      • Shi W.
      • Gao Z.
      • et al.
      A randomized clinical trial of three options for N95 respirators and medical masks in health workers.
      On the other hand, the uptake of facemask among ordinary population in diverse household and community settings ranged from 38% to 80.7% (average 55%).
      • Canini L.
      • Andreoletti L.
      • Ferrari P.
      • D’Angelo R.
      • Blanchon T.
      • Lemaitre M.
      • et al.
      Surgical mask to prevent influenza transmission in households: a cluster randomized trial.
      • 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.
      • Cowling B.J.
      • Fung R.O.
      • Cheng C.K.
      • Fang V.J.
      • Chan K.H.
      • Seto W.H.
      • et al.
      Preliminary findings of a randomized trial of non-pharmaceutical interventions to prevent influenza transmission in households.
      • Larson E.L.
      • Ferng Y.H.
      • Wong-McLoughlin J.
      • Wang S.
      • Haber M.
      • Morse S.S.
      Impact of non-pharmaceutical interventions on URIs and influenza in crowded, urban households.
      • 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.
      • Suess T.
      • Remschmidt C.
      • Schink S.B.
      • Schweiger B.
      • Nitsche A.
      • Schroeder K.
      • et al.
      The role of facemasks and hand hygiene in the prevention of influenza transmission in households: results from a cluster randomised trial; Berlin, Germany, 2009-2011.
      • Simmerman J.M.
      • Suntarattiwong P.
      • Levy J.
      • Jarman R.G.
      • Kaewchana S.
      • Gibbons R.V.
      • et al.
      Findings from a household randomized controlled trial of hand washing and face masks to reduce influenza transmission in Bangkok, Thailand.
      This could be explained by several individual or organisational factors. For example, HCWs have firsthand knowledge about the risk of respiratory infections and the role of preventive measurements in Hajj.
      • Memish Z.A.
      • Assiri A.M.
      • Alshehri M.
      • Hussain R.
      • Alomar I.
      The prevalance of respiratory viruses among healthcare workers serving pilgrims in Makkah during the 2009 influenza A (H1N1) pandemic.
      Similarly, studies in non-MGs settings showed a positive relationship between HCWs’ knowledge about the risk of infectious diseases and their compliance to preventive measures including the use of facemask.
      • Albano L.
      • Matuozzo A.
      • Marinelli P.
      • Di Giuseppe G.
      Knowledge, attitudes and behaviour of hospital health-care workers regarding influenza A/H1N1: a cross sectional survey.
      • MacIntyre C.R.
      • Chughtai A.A.
      Facemasks for the prevention of infection in healthcare and community settings.
      • Nichol K.
      • McGeer A.
      • Bigelow P.
      • O’Brien-Pallas L.
      • Scott J.
      • Holness D.L.
      Behind the mask: Determinants of nurse's adherence to facial protective equipment.
      Organisational factors such as ready availability of facemask in health care settings, proper training programs and supportive policy of health care system could have played an important role in improving the compliance of HCWs to facemask use.
      • MacIntyre C.R.
      • Chughtai A.A.
      Facemasks for the prevention of infection in healthcare and community settings.
      • Nichol K.
      • McGeer A.
      • Bigelow P.
      • O’Brien-Pallas L.
      • Scott J.
      • Holness D.L.
      Behind the mask: Determinants of nurse's adherence to facial protective equipment.
      • Gershon R.R.
      • Vlahov D.
      • Felknor S.A.
      • Vesley D.
      • Johnson P.C.
      • Delclos G.L.
      • et al.
      Compliance with universal precautions among health care workers at three regional hospitals.
      • Lau J.T.
      • Fung K.S.
      • Wong T.W.
      • Kim J.H.
      • Wong E.
      • Chung S.
      • et al.
      SARS transmission among hospital workers in Hong Kong.
      On the other hand, limited studies explored these individual and organisational factors among Hajj pilgrims. A few studies showed that providing educational session on protective measures against respiratory infections (including facemask) before Hajj was associated with significantly higher uptake of facemasks among pilgrims.
      • Barasheed O.
      • Almasri N.
      • Badahdah A.-M.
      • Heron L.
      • Taylor J.
      • McPhee K.
      • et al.
      Pilot randomised controlled trial to test effectiveness of facemasks in preventing influenza-like illness transmission among Australian hajj pilgrims in 2011.
      • Abdin E.Z.
      • Choudhry A.J.
      • Al-Naji A.
      Effect of use of face mask on Hajj-related respiratory infection among Hajjis from Riyadh - a health promotion intervention study.
      • Aljoudi A.
      • Nooh R.
      • Jamil A.
      Effect of health education advice on Saudi Hajjis, Hajj 1423 H (2003 G).
      • Al-Zahrani I.
      • Chaudhry A.
      • Alhamdan N.
      Sources of health education for international Arab pilgrims and the effect of this education on their practices towards health hazards in hajj, 1427 H (2006).
      • Khamis N.K.
      Epidemiological pattern of diseases and risk behaviors of pilgrims attending mina hospitals, hajj 1427 h (2007 g).
      Moreover, adequate accessibility and availability of facemask during Hajj may enhance the compliance of pilgrims. Abdin et al and Barasheed et al revealed a higher uptake of facemask among groups who were provided with sufficient quantity of free facemask (81.3% versus 33.6%, p < 0.01, and 76% versus 12%, p < 0.01, respectively).
      • Barasheed O.
      • Almasri N.
      • Badahdah A.-M.
      • Heron L.
      • Taylor J.
      • McPhee K.
      • et al.
      Pilot randomised controlled trial to test effectiveness of facemasks in preventing influenza-like illness transmission among Australian hajj pilgrims in 2011.
      • Abdin E.Z.
      • Choudhry A.J.
      • Al-Naji A.
      Effect of use of face mask on Hajj-related respiratory infection among Hajjis from Riyadh - a health promotion intervention study.
      However, reasons for not using facemask during Hajj have not been explored adequately. While use of facemask at Hajj has been officially recommended by Saudi Ministry of Health since 2014, it is too early to have a significant impact on pilgrims’ practice of facemask use.
      • Memish Z.A.
      • Al Rabeeah A.A.
      Health conditions for travellers to Saudi Arabia for the Umra and pilgrimage to Mecca (Hajj) - 2014.
      Although Hajj took place in different seasons (spring, winter and autumn), the uptake of facemask among Hajj pilgrims during the last decade remained generally stable (Figure 2). Findings also showed that there was no significant change in facemask uptake among Hajj pilgrims during the course of influenza A (H1N1) pandemic outburst in 2009, and the Middle East respiratory syndrome corona virus (MERS-CoV) outbreak since 2012. This does not concur with what has been reported in published studies involving the members of general public over the several outbreaks of respiratory infections in non-MG settings.
      • Condon B.J.
      • Sinha T.
      Who is that masked person: the use of face masks on Mexico City public transportation during the Influenza A (H1N1) outbreak.
      • Kuo P.C.
      • Huang J.H.
      • Liu M.D.
      Avian influenza risk perception and preventive behavior among traditional market workers and shoppers in Taiwan: practical implications for prevention.
      • Lau J.T.
      • Griffiths S.
      • Choi K.C.
      • Lin C.
      Prevalence of preventive behaviors and associated factors during early phase of the H1N1 influenza epidemic.
      • Lau J.T.
      • Griffiths S.
      • Choi K.C.
      • Tsui H.Y.
      Widespread public misconception in the early phase of the H1N1 influenza epidemic.
      • Lau J.T.
      • Kim J.H.
      • Tsui H.Y.
      • Griffiths S.
      Anticipated and current preventive behaviors in response to an anticipated human-to-human H5N1 epidemic in the Hong Kong Chinese general population.
      • Tang C.S.
      • Wong C.Y.
      Factors influencing the wearing of facemasks to prevent the severe acute respiratory syndrome among adult Chinese in Hong Kong.
      Those studies showed an increase in facemask use during the outbreaks due to participants’ perceived threat of infection. Poor awareness among many pilgrims of contemporary outbreaks might explain why their uptake of facemask did not increase even during an ongoing outbreak.
      • Gautret P.
      • Benkouiten S.
      • Salaheddine I.
      • Belhouchat K.
      • Drali T.
      • Parola P.
      • et al.
      Hajj pilgrims knowledge about Middle East respiratory syndrome coronavirus, August to September 2013.
      • Sahin M.K.
      • Aker S.
      • Kaynar Tuncel E.
      Knowledge, attitudes and practices concerning Middle East respiratory syndrome among Umrah and Hajj pilgrims in Samsun, Turkey, 2015.
      • Tashani M.
      • Alfelali M.
      • Barasheed O.
      • Fatema F.N.
      • Alqahtani A.
      • Rashid H.
      • et al.
      Australian Hajj pilgrims’ knowledge about MERS-CoV and other respiratory infections.
      Interestingly, pilgrims of Asian origin (e.g. Malaysians) had higher facemask uptake compared to pilgrims from other regions.
      • Deris Z.Z.
      • Hasan H.
      • Sulaiman S.A.
      • Wahab M.S.
      • Naing N.N.
      • Othman N.H.
      The prevalence of acute respiratory symptoms and role of protective measures among Malaysian hajj pilgrims.
      • Hashim S.
      • Ayub Z.N.
      • Mohamed Z.
      • Hasan H.
      • Harun A.
      • Ismail N.
      • et al.
      The prevalence and preventive measures of the respiratory illness among Malaysian pilgrims in 2013 hajj season.
      A polling study that evaluated the uptake of non-pharmaceutical measures during the pandemic influenza A (H1N1) of 2009 found that participants of Asian origin (e.g. Japan) had the higher facemask uptake (71%) compared to the uptake of participants of Western or Latin American origin.
      • SteelFisher G.K.
      • Blendon R.J.
      • Ward J.R.
      • Rapoport R.
      • Kahn E.B.
      • Kohl K.S.
      Public response to the 2009 influenza A H1N1 pandemic: a polling study in five countries.
      Presence of several peaks of influenza seasons in some Asian countries, overcrowding, dense smog and air pollution in many cities may explain the higher uptake of facemask among people from Asian countries;
      • Saha S.
      • Chadha M.
      • Al Mamun A.
      • Rahman M.
      • Sturm-Ramirez K.
      • Chittaganpitch M.
      • et al.
      Influenza seasonality and vaccination timing in tropical and subtropical areas of southern and south-eastern Asia.
      • Kunzli N.
      • Kutlar M.
      [Air pollution and health - counselling options for physicians].
      additionally, cultural acceptance practice of the population around facemask while in public may make a difference.
      • SteelFisher G.K.
      • Blendon R.J.
      • Ward J.R.
      • Rapoport R.
      • Kahn E.B.
      • Kohl K.S.
      Public response to the 2009 influenza A H1N1 pandemic: a polling study in five countries.
      Focused studies are required to investigate factors influencing facemask compliance among attendees of Hajj and other MGs.
      In this systematic review, pooled data of facemask effectiveness showed that participants who used facemask during Hajj are about 20% less likely to suffer from respiratory infections compared to those who do not use it. This effectiveness of facemask is inconclusive due to great heterogeneity in study questions, assessment methods, study designs and qualities, and endpoints. In regards to the research questions, three out of 13 studies investigated facemask effectiveness as the primary research objective: all three studies yielded significant results; whereas only one out of the other 10 studies that assessed facemask as a secondary or indirect outcome, yielded significant results.
      Further, there was great heterogeneity in how the frequency and duration of facemask use were assessed. Although, most of the studies used a self-reported questionnaire to quantify facemask uptake among participants, the qualitative descriptive terms that the studies used (e.g. “always”, “mostly”, “sometimes” or “never”) may have introduced subjective bias, since qualitative description varies depending on participants’ perception about the frequency and duration of use. However, only one study used measurable criteria in their questionnaires to quantify the number of facemasks used including the duration (in hours) and frequency of use, finding that using facemask more than eight hours per day was associated with significant decrease in ILI symptoms among Hajj pilgrims.
      • Barasheed O.
      • Almasri N.
      • Badahdah A.-M.
      • Heron L.
      • Taylor J.
      • McPhee K.
      • et al.
      Pilot randomised controlled trial to test effectiveness of facemasks in preventing influenza-like illness transmission among Australian hajj pilgrims in 2011.
      Using surveys with more objective options may decrease bias,
      • Kimberlin C.L.
      • Winterstein A.G.
      Validity and reliability of measurement instruments used in research.
      and provide more accurate estimate of compliance to facemask use in MGs.
      Study designs also may have contributed to variability in results. For instance, two trials, a pilot RCT and a non-randomised trial, reported facemask to be significantly effective against respiratory infections at Hajj, whereas only two out of six cohort studies reported significant results. In contrast, none of the cross-sectional studies yielded significant results. This may indicate that a higher quality study is more likely to produce convincing results.
      Finally, facemask effectiveness also differed depending on the study endpoints. For example, studies that examined effectiveness of facemask against a single respiratory symptom (such as cough, sore throat or fever) either ruled out or did not fully support its effectiveness.
      • Gautret P.
      • Benkouiten S.
      • Griffiths K.
      • Sridhar S.
      The inevitable Hajj cough: Surveillance data in French pilgrims, 2012-2014.
      • Deris Z.Z.
      • Hasan H.
      • Sulaiman S.A.
      • Wahab M.S.
      • Naing N.N.
      • Othman N.H.
      The prevalence of acute respiratory symptoms and role of protective measures among Malaysian hajj pilgrims.
      • Maslamani Y.
      • Choudhry A.J.
      Health related experiences among international pilgrims departing through King Abdul Aziz international airport, Jeddah, Saudi Arabia, Hajj 1431 H (2010).
      This is most likely because singular endpoints are often prone to subjective biases due to their non-specificity. In addition, solitary respiratory symptoms may result from causes other than infections; for instance, cough may result from exposure to dust or smoke during Hajj or may be a manifestation of a chronic respiratory condition of non-infectious aetiology, e.g., bronchial asthma.
      • Alqahtani A.S.
      • BinDhim N.F.
      • Tashani M.
      • Willaby H.W.
      • Wiley K.E.
      • Heywood A.E.
      • et al.
      Pilot use of a novel smartphone application to track traveller health behaviour and collect infectious disease data during a mass gathering: Hajj pilgrimage 2014.
      On the other hand, most of the studies that used syndromic criteria (constellation of symptoms) as an endpoint reported facemasks to be effective against respiratory infections during Hajj.
      • Barasheed O.
      • Almasri N.
      • Badahdah A.-M.
      • Heron L.
      • Taylor J.
      • McPhee K.
      • et al.
      Pilot randomised controlled trial to test effectiveness of facemasks in preventing influenza-like illness transmission among Australian hajj pilgrims in 2011.
      • Abdin E.Z.
      • Choudhry A.J.
      • Al-Naji A.
      Effect of use of face mask on Hajj-related respiratory infection among Hajjis from Riyadh - a health promotion intervention study.

      Zein U. The role of using masks to reduce acute upper respiratory tract infection in pilgrims. Abstract No. 7. 4th Asia Pacific travel health conference, Shanghai, PR China; October; 2002, p. e23.

      • Al-Jasser F.S.
      • Kabbash I.A.
      • Almazroa M.A.
      • Memish Z.A.
      Patterns of diseases and preventive measures among domestic hajjis from Central, Saudi Arabia.
      • Choudhry A.J.
      • Al-Mudaimegh K.S.
      • Turkistani A.M.
      • Al-Hamdan N.A.
      Hajj-associated acute respiratory infection among hajjis from Riyadh.
      This is most likely due to the fact that syndromic endpoints are more specific for an illness than a singular symptom. Only one study used laboratory-confirmed infection as an endpoint, but its sample size was relatively small (n = 104) and it failed to demonstrate statistically significant protectiveness of facemasks against respiratory viral infections among Hajj HCWs.
      • Memish Z.A.
      • Assiri A.M.
      • Alshehri M.
      • Hussain R.
      • Alomar I.
      The prevalance of respiratory viruses among healthcare workers serving pilgrims in Makkah during the 2009 influenza A (H1N1) pandemic.
      Similarly, in non-MG settings, effectiveness of facemask varied depending on the study endpoint.
      • Jacobs J.L.
      • Ohde S.
      • Takahashi O.
      • Tokuda Y.
      • Omata F.
      • Fukui T.
      Use of surgical face masks to reduce the incidence of the common cold among health care workers in Japan: a randomized controlled trial.
      • MacIntyre C.R.
      • Seale H.
      • Dung T.C.
      • Hien N.T.
      • Nga P.T.
      • Chughtai A.A.
      • et al.
      A cluster randomised trial of cloth masks compared with medical masks in healthcare workers.
      • MacIntyre C.R.
      • Wang Q.
      • Cauchemez S.
      • Seale H.
      • Dwyer D.E.
      • Yang P.
      • et al.
      A cluster randomized clinical trial comparing fit-tested and non-fit-tested N95 respirators to medical masks to prevent respiratory virus infection in health care workers.
      • MacIntyre C.R.
      • Wang Q.
      • Seale H.
      • Yang P.
      • Shi W.
      • Gao Z.
      • et al.
      A randomized clinical trial of three options for N95 respirators and medical masks in health workers.
      • Canini L.
      • Andreoletti L.
      • Ferrari P.
      • D’Angelo R.
      • Blanchon T.
      • Lemaitre M.
      • et al.
      Surgical mask to prevent influenza transmission in households: a cluster randomized trial.
      • 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.
      • Cowling B.J.
      • Fung R.O.
      • Cheng C.K.
      • Fang V.J.
      • Chan K.H.
      • Seto W.H.
      • et al.
      Preliminary findings of a randomized trial of non-pharmaceutical interventions to prevent influenza transmission in households.
      • Larson E.L.
      • Ferng Y.H.
      • Wong-McLoughlin J.
      • Wang S.
      • Haber M.
      • Morse S.S.
      Impact of non-pharmaceutical interventions on URIs and influenza in crowded, urban households.
      • 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.
      • Suess T.
      • Remschmidt C.
      • Schink S.B.
      • Schweiger B.
      • Nitsche A.
      • Schroeder K.
      • et al.
      The role of facemasks and hand hygiene in the prevention of influenza transmission in households: results from a cluster randomised trial; Berlin, Germany, 2009-2011.
      • Simmerman J.M.
      • Suntarattiwong P.
      • Levy J.
      • Jarman R.G.
      • Kaewchana S.
      • Gibbons R.V.
      • et al.
      Findings from a household randomized controlled trial of hand washing and face masks to reduce influenza transmission in Bangkok, Thailand.
      • Aiello A.E.
      • Murray G.F.
      • Perez V.
      • Coulborn R.M.
      • Davis B.M.
      • Uddin M.
      • et al.
      Mask use, hand hygiene, and seasonal influenza-like illness among young adults: a randomized intervention trial.
      • Loeb M.
      • Dafoe N.
      • Mahony J.
      • John M.
      • Sarabia A.
      • Glavin V.
      • et al.
      Surgical mask vs N95 respirator for preventing influenza among health care workers: a randomized trial.
      • MacIntyre C.R.
      • Wang Q.
      • Rahman B.
      • Seale H.
      • Ridda I.
      • Gao Z.
      • et al.
      Efficacy of face masks and respirators in preventing upper respiratory tract bacterial colonization and co-infection in hospital healthcare workers.
      Meta-analysis of RCTs involving facemask in non-MGs showed efficacy against ILI but not against laboratory-confirmed influenza.
      • Bin-Reza F.
      • Lopez Chavarrias V.
      • Nicoll A.
      • Chamberland M.E.
      The use of masks and respirators to prevent transmission of influenza: a systematic review of the scientific evidence.
      • Rashid H.
      • Booy R.
      • Heron L.
      • Memish Z.A.
      • Nguyen-Van-Tam J.
      • Barasheed O.
      • et al.
      Unmasking masks in Makkah: preventing influenza at Hajj.
      • Wang M.
      • Barasheed O.
      • Rashid H.
      • Booy R.
      • El Bashir H.
      • Haworth E.
      • et al.
      A cluster-randomised controlled trial to test the efficacy of facemasks in preventing respiratory viral infection among Hajj pilgrims.
      This study is the first focussed systematic review that describes both the uptake and effectiveness of facemasks against respiratory infections in MGs, and it compiles a data pool of 12710 participants originating from more than 50 countries. However, the main limitation is that most of the studies were of ‘average’ or ‘below average’ quality. There was only one RCT but that was a pilot trial of small sample size, and there was another ‘trial’ published in a non-indexed journal that did not report methodological details including whether and how randomisation was done. As all included studies were conducted only in the context of Hajj, it is not possible to generalise the results to other MGs. A large scale clustered RCT is currently in its final phase that will measure the efficacy of facemasks against both ‘syndromic’ and laboratory-confirmed viral infections.
      • Wang M.
      • Barasheed O.
      • Rashid H.
      • Booy R.
      • El Bashir H.
      • Haworth E.
      • et al.
      A cluster-randomised controlled trial to test the efficacy of facemasks in preventing respiratory viral infection among Hajj pilgrims.
      The full results of the trial, once available, are likely to provide firmer evidence on the usefulness of facemask against respiratory infections among attendees of MGs.
      In summary, the use of facemask among attendees of a particular MG (Hajj) remains almost steady with negligible increase throughout the last decade with an average uptake of 50%. Facemasks seem to be beneficial against certain respiratory infections during Hajj but not definitively proven.

      Conflicts of interest

      Professor Robert Booy has received funding from Baxter, CSL, GSK, Merck, Novartis, Pfizer, Roche, Romark and Sanofi Pasteur for the conduct of sponsored research, travel to present at conferences or consultancy work; all funding received is directed to research accounts at The Children's Hospital at Westmead. Dr Harunor Rashid received fees from Pfizer and Novartis for consulting or serving on an advisory board. The other authors have declared no conflict of interest in relation to this work.

      Acknowledgments

      The authors would acknowledge the support of Ms. Trish Bennett, Manager, Medical Library, The Children's Hospital at Westmead, NSW, Australia, for help with literature search.

      References

        • Benkouiten S.
        • Charrel R.
        • Belhouchat K.
        • Drali T.
        • Salez N.
        • Nougairede A.
        • et al.
        Circulation of respiratory viruses among pilgrims during the 2012 Hajj pilgrimage.
        Clin Infect Dis. 2013; 57: 992-1000
        • Benkouiten S.
        • Charrel R.
        • Belhouchat K.
        • Drali T.
        • Nougairede A.
        • Salez N.
        • et al.
        Respiratory viruses and bacteria among pilgrims during the 2013 Hajj.
        Emerg Infect Dis. 2014; 20: 1821-1827
        • Madani T.A.
        • Ghabrah T.M.
        • Al-Hedaithy M.A.
        • Alhazmi M.A.
        • Alazraqi T.A.
        • Albarrak A.M.
        • et al.
        Causes of hospitalization of pilgrims in the Hajj season of the Islamic year 1423 (2003).
        Ann Saudi Med. 2006; 26: 346-351
        • Blyth C.C.
        • Foo H.
        • van Hal S.J.
        • Hurt A.C.
        • Barr I.G.
        • McPhie K.
        • et al.
        Influenza outbreaks during World Youth Day 2008 mass gathering.
        Emerg Infect Dis. 2010; 16: 809-815
        • Zepeda-Lopez H.M.
        • Perea-Araujo L.
        • Miliar-Garcia A.
        • Dominguez-Lopez A.
        • Xoconostle-Cazarez B.
        • Lara-Padilla E.
        • et al.
        Inside the outbreak of the 2009 influenza A (H1N1)v virus in Mexico.
        PLoS ONE. 2010; 5: e13256
        • Organization W.H.
        Communicable disease alert and response for mass gatherings: key considerations.
        WHO, Geneva2008: 32-33
      1. Health conditions for travellers to Saudi Arabia for the pilgrimage to Mecca (Hajj), 2014. Wkly Epidemiol Rec 2014; 89:357-60.

        • Alqahtani A.S.
        • Rashid H.
        • Heywood A.E.
        Vaccinations against respiratory tract infections at Hajj.
        Clin Microbiol Infect. 2015; 21: 115-127
        • Aleflali M.
        • Khandaker G.
        • Booy R.
        • Rashid H.
        Mismatching between circulating strains and vaccine strains of influenza: Effect on Hajj pilgrims from both hemispheres.
        Hum Vaccin Immunother. 2015; (in press)
        • Dixit R.
        • Khandaker G.
        • Ilgoutz S.
        • Rashid H.
        • Booy R.
        Emergence of oseltamivir resistance: control and management of influenza before, during and after the pandemic.
        Infect Disord Drug Targets. 2013; 13: 34-45
        • Benkouiten S.
        • Brouqui P.
        • Gautret P.
        Non-pharmaceutical interventions for the prevention of respiratory tract infections during Hajj pilgrimage.
        Travel Med Infect Dis. 2014; 12: 429-442
        • Haworth E.
        • Barasheed O.
        • Memish Z.A.
        • Rashid H.
        • Booy R.
        Prevention of influenza at Hajj: applications for mass gatherings.
        J R Soc Med. 2013; 106: 215-223
        • Hobday R.A.
        • Cason J.W.
        The open-air treatment of pandemic influenza.
        Am J Public Health. 2009; 99: S236-S242
        • Bin-Reza F.
        • Lopez Chavarrias V.
        • Nicoll A.
        • Chamberland M.E.
        The use of masks and respirators to prevent transmission of influenza: a systematic review of the scientific evidence.
        Influenza Other Respir Viruses. 2012; 6: 257-267
        • Rashid H.
        • Booy R.
        • Heron L.
        • Memish Z.A.
        • Nguyen-Van-Tam J.
        • Barasheed O.
        • et al.
        Unmasking masks in Makkah: preventing influenza at Hajj.
        Clin Infect Dis. 2012; 54: 151-153
        • Sim S.W.
        • Moey K.S.
        • Tan N.C.
        The use of facemasks to prevent respiratory infection: a literature review in the context of the Health Belief Model.
        Singapore Med J. 2014; 55: 160-167
        • Jefferson T.
        • Foxlee R.
        • Del Mar C.
        • Dooley L.
        • Ferroni E.
        • Hewak B.
        • et al.
        Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review.
        BMJ. 2008; 336: 77-80
        • Barasheed O.
        • Almasri N.
        • Badahdah A.-M.
        • Heron L.
        • Taylor J.
        • McPhee K.
        • et al.
        Pilot randomised controlled trial to test effectiveness of facemasks in preventing influenza-like illness transmission among Australian hajj pilgrims in 2011.
        Infect Disord Drug Targets. 2014; 14: 110-116
        • Moher D.
        • Liberati A.
        • Tetzlaff J.
        • Altman D.G.
        Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement.
        J Clin Epidemiol. 2009; 62: 1006-1012
        • Abdin E.Z.
        • Choudhry A.J.
        • Al-Naji A.
        Effect of use of face mask on Hajj-related respiratory infection among Hajjis from Riyadh - a health promotion intervention study.
        Saudi Epidemiol Bull. 2005; 12: 27-28
        • Elachola H.
        • Assiri A.M.
        • Memish Z.A.
        Mass gathering-related mask use during 2009 pandemic influenza A (H1N1) and Middle East respiratory syndrome coronavirus.
        Int J Infect Dis. 2014; 20: 77-78
      2. Zein U. The role of using masks to reduce acute upper respiratory tract infection in pilgrims. Abstract No. 7. 4th Asia Pacific travel health conference, Shanghai, PR China; October; 2002, p. e23.

        • Ahmed G.Y.
        • Balkhy H.H.
        • Bafaqeer S.
        • Al-Jasir B.
        • Althaqafi A.
        Acceptance and Adverse Effects of H1N1 Vaccinations Among a Cohort of National Guard Health Care Workers during the 2009 Hajj Season.
        BMC Res Notes. 2011; 4: 61
        • Al-Asmary S.
        • Al-Shehri A.S.
        • Abou-Zeid A.
        • Abdel-Fattah M.
        • Hifnawy T.
        • El-Said T.
        Acute respiratory tract infections among Hajj medical mission personnel, Saudi Arabia.
        Int J Infect Dis. 2007; 11: 268-272
        • Memish Z.A.
        • Assiri A.M.
        • Alshehri M.
        • Hussain R.
        • Alomar I.
        The prevalance of respiratory viruses among healthcare workers serving pilgrims in Makkah during the 2009 influenza A (H1N1) pandemic.
        Travel Med Infect Dis. 2012; 10: 18-24
        • Al-Jasser F.S.
        • Kabbash I.A.
        • Almazroa M.A.
        • Memish Z.A.
        Patterns of diseases and preventive measures among domestic hajjis from Central, Saudi Arabia.
        Saudi Med J. 2012; 33: 879-886
        • Aljoudi A.
        • Nooh R.
        • Jamil A.
        Effect of health education advice on Saudi Hajjis, Hajj 1423 H (2003 G).
        Saudi Epidemiol Bull. 2004; 11
        • Choudhry A.J.
        • Al-Mudaimegh K.S.
        • Turkistani A.M.
        • Al-Hamdan N.A.
        Hajj-associated acute respiratory infection among hajjis from Riyadh.
        East Mediterr Health J. 2006; 12: 300-309
        • Alqahtani A.S.
        • BinDhim N.F.
        • Tashani M.
        • Willaby H.W.
        • Wiley K.E.
        • Heywood A.E.
        • et al.
        Pilot use of a novel smartphone application to track traveller health behaviour and collect infectious disease data during a mass gathering: Hajj pilgrimage 2014.
        J Epidemiol Glob Health. 2015; (in press)
        • Balaban V.
        • Stauffer W.M.
        • Hammad A.
        • Afgarshe M.
        • Abd-Alla M.
        • Ahmed Q.
        • et al.
        Protective practices and respiratory illness among US travelers to the 2009 Hajj.
        J Travel Med. 2012; 19: 163-168
        • Emamian M.H.
        • Hassani A.M.
        • Fateh M.
        Respiratory Tract Infections and its Preventive Measures among Hajj Pilgrims, 2010: A Nested Case Control Study.
        Int J Prev Med. 2013; 4: 1030-1035
        • Gautret P.
        • Benkouiten S.
        • Griffiths K.
        • Sridhar S.
        The inevitable Hajj cough: Surveillance data in French pilgrims, 2012-2014.
        Travel Med Infect Dis. 2015;
        • Gautret P.
        • Vu Hai V.
        • Sani S.
        • Doutchi M.
        • Parola P.
        • Brouqui P.
        Protective measures against acute respiratory symptoms in French pilgrims participating in the Hajj of 2009.
        J Travel Med. 2011; 18: 53-55
        • Al-Maghderi Y.
        • Al-Joudi A.
        • Choudhry A.J.
        • Al-Rabeah A.M.
        • Ibrahim M.
        • Turkistani A.M.
        Behavioral Risk Factors for Disease during Hajj 1422 H, (2002 G).
        Saudi Epidemiol Bull. 2002; 9: 19-20
        • Al-Shihry A.M.
        • Al-Khan A.A.
        • Mohammed A.G.
        Pre-Hajj Health related advice.
        Saudi Epidemiol Bull. 1999; 6: 29
        • Al-Zahrani I.
        • Chaudhry A.
        • Alhamdan N.
        Sources of health education for international Arab pilgrims and the effect of this education on their practices towards health hazards in hajj, 1427 H (2006).
        Saudi Epidemiol Bull. 2007; 14: 25-29
        • Deris Z.Z.
        • Hasan H.
        • Sulaiman S.A.
        • Wahab M.S.
        • Naing N.N.
        • Othman N.H.
        The prevalence of acute respiratory symptoms and role of protective measures among Malaysian hajj pilgrims.
        J Travel Med. 2010; 17: 82-88
        • Khamis N.K.
        Epidemiological pattern of diseases and risk behaviors of pilgrims attending mina hospitals, hajj 1427 h (2007 g).
        J Egypt Public Health Assoc. 2008; 83: 15-33
        • Maslamani Y.
        • Choudhry A.J.
        Health related experiences among international pilgrims departing through King Abdul Aziz international airport, Jeddah, Saudi Arabia, Hajj 1431 H (2010).
        Saudi Epidemiol Bull. 2011; 18
        • Hashim S.
        • Ayub Z.N.
        • Mohamed Z.
        • Hasan H.
        • Harun A.
        • Ismail N.
        • et al.
        The prevalence and preventive measures of the respiratory illness among Malaysian pilgrims in 2013 hajj season.
        J Travel Med. 2016; 23 (in press)
        • Alqahtani A.S.
        • Sheikh M.
        • Wiley K.
        • Heywood A.E.
        Australian Hajj pilgrims’ infection control beliefs and practices: Insight with implications for public health approaches.
        Travel Med Infect Dis. 2015; 13: 329-334
        • Jacobs J.L.
        • Ohde S.
        • Takahashi O.
        • Tokuda Y.
        • Omata F.
        • Fukui T.
        Use of surgical face masks to reduce the incidence of the common cold among health care workers in Japan: a randomized controlled trial.
        Am J Infect Control. 2009; 37: 417-419
        • MacIntyre C.R.
        • Seale H.
        • Dung T.C.
        • Hien N.T.
        • Nga P.T.
        • Chughtai A.A.
        • et al.
        A cluster randomised trial of cloth masks compared with medical masks in healthcare workers.
        BMJ Open. 2015; 5: e006577
        • MacIntyre C.R.
        • Wang Q.
        • Cauchemez S.
        • Seale H.
        • Dwyer D.E.
        • Yang P.
        • et al.
        A cluster randomized clinical trial comparing fit-tested and non-fit-tested N95 respirators to medical masks to prevent respiratory virus infection in health care workers.
        Influenza Other Respir Viruses. 2011; 5: 170-179
        • MacIntyre C.R.
        • Wang Q.
        • Seale H.
        • Yang P.
        • Shi W.
        • Gao Z.
        • et al.
        A randomized clinical trial of three options for N95 respirators and medical masks in health workers.
        Am J Respir Crit Care Med. 2013; 187: 960-966
        • Canini L.
        • Andreoletti L.
        • Ferrari P.
        • D’Angelo R.
        • Blanchon T.
        • Lemaitre M.
        • et al.
        Surgical mask to prevent influenza transmission in households: a cluster randomized trial.
        PLoS ONE. 2010; 5: e13998
        • 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
        • Cowling B.J.
        • Fung R.O.
        • Cheng C.K.
        • Fang V.J.
        • Chan K.H.
        • Seto W.H.
        • et al.
        Preliminary findings of a randomized trial of non-pharmaceutical interventions to prevent influenza transmission in households.
        PLoS ONE. 2008; 3: e2101
        • Larson E.L.
        • Ferng Y.H.
        • Wong-McLoughlin J.
        • Wang S.
        • Haber M.
        • Morse S.S.
        Impact of non-pharmaceutical interventions on URIs and influenza in crowded, urban households.
        Public Health Rep. 2010; 125: 178-191
        • 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
        • Suess T.
        • Remschmidt C.
        • Schink S.B.
        • Schweiger B.
        • Nitsche A.
        • Schroeder K.
        • et al.
        The role of facemasks and hand hygiene in the prevention of influenza transmission in households: results from a cluster randomised trial; Berlin, Germany, 2009-2011.
        BMC Infect Dis. 2012; 12: 26
        • Simmerman J.M.
        • Suntarattiwong P.
        • Levy J.
        • Jarman R.G.
        • Kaewchana S.
        • Gibbons R.V.
        • et al.
        Findings from a household randomized controlled trial of hand washing and face masks to reduce influenza transmission in Bangkok, Thailand.
        Influenza Other Respir Viruses. 2011; 5: 256-267
        • Albano L.
        • Matuozzo A.
        • Marinelli P.
        • Di Giuseppe G.
        Knowledge, attitudes and behaviour of hospital health-care workers regarding influenza A/H1N1: a cross sectional survey.
        BMC Infect Dis. 2014; 14: 208
        • MacIntyre C.R.
        • Chughtai A.A.
        Facemasks for the prevention of infection in healthcare and community settings.
        BMJ. 2015; 350: h694
        • Nichol K.
        • McGeer A.
        • Bigelow P.
        • O’Brien-Pallas L.
        • Scott J.
        • Holness D.L.
        Behind the mask: Determinants of nurse's adherence to facial protective equipment.
        Am J Infect Control. 2013; 41: 8-13
        • Gershon R.R.
        • Vlahov D.
        • Felknor S.A.
        • Vesley D.
        • Johnson P.C.
        • Delclos G.L.
        • et al.
        Compliance with universal precautions among health care workers at three regional hospitals.
        Am J Infect Control. 1995; 23: 225-236
        • Lau J.T.
        • Fung K.S.
        • Wong T.W.
        • Kim J.H.
        • Wong E.
        • Chung S.
        • et al.
        SARS transmission among hospital workers in Hong Kong.
        Emerg Infect Dis. 2004; 10: 280-286
        • Memish Z.A.
        • Al Rabeeah A.A.
        Health conditions for travellers to Saudi Arabia for the Umra and pilgrimage to Mecca (Hajj) - 2014.
        J Epidemiol Glob Health. 2014; 4: 73-75
        • Condon B.J.
        • Sinha T.
        Who is that masked person: the use of face masks on Mexico City public transportation during the Influenza A (H1N1) outbreak.
        Health Policy. 2010; 95: 50-56
        • Kuo P.C.
        • Huang J.H.
        • Liu M.D.
        Avian influenza risk perception and preventive behavior among traditional market workers and shoppers in Taiwan: practical implications for prevention.
        PLoS ONE. 2011; 6: e24157
        • Lau J.T.
        • Griffiths S.
        • Choi K.C.
        • Lin C.
        Prevalence of preventive behaviors and associated factors during early phase of the H1N1 influenza epidemic.
        Am J Infect Control. 2010; 38: 374-380
        • Lau J.T.
        • Griffiths S.
        • Choi K.C.
        • Tsui H.Y.
        Widespread public misconception in the early phase of the H1N1 influenza epidemic.
        J Infect. 2009; 59: 122-127
        • Lau J.T.
        • Kim J.H.
        • Tsui H.Y.
        • Griffiths S.
        Anticipated and current preventive behaviors in response to an anticipated human-to-human H5N1 epidemic in the Hong Kong Chinese general population.
        BMC Infect Dis. 2007; 7: 18
        • Tang C.S.
        • Wong C.Y.
        Factors influencing the wearing of facemasks to prevent the severe acute respiratory syndrome among adult Chinese in Hong Kong.
        Prev Med. 2004; 39: 1187-1193
        • Gautret P.
        • Benkouiten S.
        • Salaheddine I.
        • Belhouchat K.
        • Drali T.
        • Parola P.
        • et al.
        Hajj pilgrims knowledge about Middle East respiratory syndrome coronavirus, August to September 2013.
        Euro Surveill. 2013; 18: 20604
        • Sahin M.K.
        • Aker S.
        • Kaynar Tuncel E.
        Knowledge, attitudes and practices concerning Middle East respiratory syndrome among Umrah and Hajj pilgrims in Samsun, Turkey, 2015.
        Euro Surveill. 2015; 20
        • Tashani M.
        • Alfelali M.
        • Barasheed O.
        • Fatema F.N.
        • Alqahtani A.
        • Rashid H.
        • et al.
        Australian Hajj pilgrims’ knowledge about MERS-CoV and other respiratory infections.
        Virol Sin. 2014; 29: 318-320
        • SteelFisher G.K.
        • Blendon R.J.
        • Ward J.R.
        • Rapoport R.
        • Kahn E.B.
        • Kohl K.S.
        Public response to the 2009 influenza A H1N1 pandemic: a polling study in five countries.
        Lancet Infect Dis. 2012; 12: 845-850
        • Saha S.
        • Chadha M.
        • Al Mamun A.
        • Rahman M.
        • Sturm-Ramirez K.
        • Chittaganpitch M.
        • et al.
        Influenza seasonality and vaccination timing in tropical and subtropical areas of southern and south-eastern Asia.
        Bull World Health Organ. 2014; 92: 318-330
        • Kunzli N.
        • Kutlar M.
        [Air pollution and health - counselling options for physicians].
        Ther Umsch. 2013; 70: 725-732
        • Kimberlin C.L.
        • Winterstein A.G.
        Validity and reliability of measurement instruments used in research.
        Am J Health Syst Pharm. 2008; 65: 2276-2284
        • Aiello A.E.
        • Murray G.F.
        • Perez V.
        • Coulborn R.M.
        • Davis B.M.
        • Uddin M.
        • et al.
        Mask use, hand hygiene, and seasonal influenza-like illness among young adults: a randomized intervention trial.
        J Infect Dis. 2010; 201: 491-498
        • Loeb M.
        • Dafoe N.
        • Mahony J.
        • John M.
        • Sarabia A.
        • Glavin V.
        • et al.
        Surgical mask vs N95 respirator for preventing influenza among health care workers: a randomized trial.
        JAMA. 2009; 302: 1865-1871
        • MacIntyre C.R.
        • Wang Q.
        • Rahman B.
        • Seale H.
        • Ridda I.
        • Gao Z.
        • et al.
        Efficacy of face masks and respirators in preventing upper respiratory tract bacterial colonization and co-infection in hospital healthcare workers.
        Prev Med. 2014; 62: 1-7
        • Wang M.
        • Barasheed O.
        • Rashid H.
        • Booy R.
        • El Bashir H.
        • Haworth E.
        • et al.
        A cluster-randomised controlled trial to test the efficacy of facemasks in preventing respiratory viral infection among Hajj pilgrims.
        J Epidemiol Glob Health. 2015; 5: 181-189