LAUSR

Introduction Synthesis of the available evidence on the effectiveness of medical and cloth facemask use by the general public in community settings is required to learn lessons for future respiratory epidemics/pandemics. Method We utilized search terms relating to facemasks, infection, and community settings on PubMed, the Cochrane Library Database, and Google Scholar. A meta-analysis was conducted utilizing a random-effects model. Results The review included 12 primary studies on the effectiveness of medical facemask use to prevent influenza, influenza-like illness, SARS-CoV and SARS-CoV-2 transmission. Our meta-analysis demonstrates that facemask use significantly reduces the risk of transmitting these respiratory infections (pooled OR = 0.66, 95% confidence interval: 0.54-0.81). Of the 12 studies, ten clinical trials suggest that respiratory infection incidence is lower with high medical facemask compliance, early use, and use in combination with intensive hand hygiene. One cohort study conducted during the SARS-CoV-2 pandemic, demonstrated facemasks are effective in reducing SARS-CoV-2 transmission when used before those infected develop symptoms. One case-control study reported that controls used medical facemasks more often than cases infected with SARS-CoV (p-value<0.05). No primary study on cloth facemask effectiveness to prevent respiratory infection transmission was found. Conclusion Based on the available evidence, we recommend medical facemask use by healthy and sick individuals for preventing respiratory infection transmission in community settings. Medical facemask effectiveness is dependent on compliance and utilization in combination with preventive measures such as intensive hand hygiene. Currently, no direct evidence is available in humans supporting the recommendation of cloth facemask use to prevent respiratory infection transmission.