South Africa - Rapid reviews of the effects of cloth and medical masks for preventing transmission of SARS-CoV-2 in community and household settings
Reference ID | Rapidreviewsoftheeffectsofclothandmedicalmasks |
Year | 2020 |
Country | South Africa |
Producer(s) |
Terusha Chetty - Health Systems Research Unit, South African Medical Research Council, South Africa Vundli Ramokolo - Health Systems Research Unit, South African Medical Research Council, South Af |
Collection(s) | |
Metadata |
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Created on
Oct 21, 2020
Last modified
Oct 21, 2020
Page views
857
Overview
Identification
ID Number Rapidreviewsoftheeffectsofclothandmedicalmasks |
Overview
Abstract
Abstract BackgroundEvidence on mask use in the general population is needed to inform SARS-CoV-2 responses.
Objective
To assess effects of cloth and medical masks for preventing SARS-CoV-2 transmission in community settings.
Research Methods
Two rapid reviews were conducted searching three electronic databases (PubMed, Embase, Cochrane Library) on 30 and 31 March 2020 and two trials registries: www.clinicaltrials.gov
Results
Reviewers screened 821 records and assessed nine full-text articles for eligibility. One and seven RCTs were included for cloth and medical mask reviews, respectively.
Cloth masks
No SARS-CoV-2 specific RCTs were identified. There were no cloth mask RCTs in community settings; a single RCT in health care workers provided indirect evidence. Compared to medical masks, cloth masks probably increase clinical respiratory illnesses (relative risk (RR)=1.56, 95% CI: 0.98, 2.49)) and laboratory-confirmed respiratory virus infections (RR=1.54, 95% CI: 0.88, 2.70). GRADE certainty was moderate. Evidence for influenza-like illnesses (ILI) was uncertain (RR=13.00, 95% CI: 1.69, 100.03) due to very serious imprecision.
Medical masks: Community settings
Two RCTs evaluated medical masks versus no masks for protecting wearers from ILI among university students in residence. These trials provide low certainty evidence that medical masks may make little to no difference to infection risk versus no masks (RR=0.98, 95% CI: 0.81, 1.19). Evidence was downgraded for serious bias and indirectness.
Household settings
Five RCTs provide low certainty evidence that medical masks may slightly reduce infection risk by 19% versus no masks (RR=0.81, 95% CI: 0.55, 1.20). The effect ranged from 45% risk reduction to 20% increased risk. Evidence was downgraded for serious bias and imprecision.
Conclusion
A hospital-based RCT provided indirect evidence that cloth masks increased infection risk versus medical masks. There were no studies of cloth masks in community settings. There was low certainty evidence of infection risk reduction in medical masks versus no masks. Direct supportive evidence for cloth and medical mask efficacy and effectiveness are lacking. Decision- making for mask use may consider other factors such as feasibility, absence of harms and SARS- CoV-2 transmission factors; however, well-designed comparative effectiveness studies are required to inform policy and future pandemic preparedness.
Producers and Sponsors
Primary Investigator(s)
Name | Affiliation |
---|---|
Terusha Chetty | Health Systems Research Unit, South African Medical Research Council, South Africa |
Vundli Ramokolo | Health Systems Research Unit, South African Medical Research Council, South Africa |
Kate Rees | Department of Community Health, School of Public Health, University of Witwatersrand, Johannesburg, South Africa |
Tamara Kredo | Cochrane South Africa, South African Medical Research Council, South Africa |
Yusentha Balakrishna | Biostatistics Unit, South African Medical Research Council, South Africa |
Catherine Mathews | Health Systems Research Unit, South African Medical Research Council, South Africa |
Nandi Siegfried | Health Systems Research Unit, South African Medical Research Council, South Africa |