title: Uptake and effectiveness of facemask against respiratory infections at mass gatherings: a systematic review.
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: 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. Electronic address: barasheed.o@kamc.med.sa.
authors.forename: Osamah
authors.initials: O
authors.lastname: Barasheed
authors.affiliation: 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.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Alfelali
authors.affiliation: Ministry of Health, Abha, Saudi Arabia.
authors.forename: Sami
authors.initials: S
authors.lastname: Mushta
authors.affiliation: Umm Al-Qura University Medical Center, Umm Al-Qura University, Makkah, Saudi Arabia.
authors.forename: Hamid
authors.initials: H
authors.lastname: Bokhary
authors.affiliation: Research Center, King Abdullah Medical City (KAMC), Makkah, P.O. Box: 57657, Saudi Arabia.
authors.forename: Jassir
authors.initials: J
authors.lastname: Alshehri
authors.affiliation: 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.
authors.forename: Ammar A
authors.initials: AA
authors.lastname: Attar
authors.affiliation: 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.
authors.forename: Robert
authors.initials: R
authors.lastname: Booy
authors.affiliation: 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.
authors.forename: Harunor
authors.initials: H
authors.lastname: Rashid
mesh_terms: D003441:Crowding; D006693:Holidays; D006801:Humans; D008397:Masks; D012134:Respiratory Protective Devices; D012141:Respiratory Tract Infections / Q000517:prevention & control*; D012307:Risk Factors
keywords: Facemask; Hajj; Influenza-like illness; Mass gathering; Pilgrim; Respiratory infections