Wearing masks in public is effective at reducing the spread of COVID-19, especially when compliance is high, and it is recommended as a part of broader health strategies.
- Masks reduce COVID-19 transmission by limiting respiratory particles. - Public mask wearing is most effective with high compliance. - Cloth masks recommended due to medical mask shortages. - Focus on source control: infectious individuals wearing masks benefits the population. - Public officials should encourage widespread mask use and appropriate regulations.
This is from PubMed in 2023 at https://pubmed.ncbi.nlm.nih.gov/33431650/
COVID-19, masks, transmissibility, source control, public health
Abstract
The science around the use of masks by the public to impede COVID-19 transmission is advancing rapidly. In this narrative review, we develop an analytical framework to examine mask usage, synthesizing the relevant literature to inform multiple areas: population impact, transmission characteristics, source control, wearer protection, sociological considerations, and implementation considerations. A primary route of transmission of COVID-19 is via respiratory particles, and it is known to be transmissible from presymptomatic, paucisymptomatic, and asymptomatic individuals. Reducing disease spread requires two things: limiting contacts of infected individuals via physical distancing and other measures and reducing the transmission probability per contact. The preponderance of evidence indicates that mask wearing reduces transmissibility per contact by reducing transmission of infected respiratory particles in both laboratory and clinical contexts. Public mask wearing is most effective at reducing spread of the virus when compliance is high. Given the current shortages of medical masks, we recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies. Because many respiratory particles become smaller due to evaporation, we recommend increasing focus on a previously overlooked aspect of mask usage: mask wearing by infectious people ("source control") with benefits at the population level, rather than only mask wearing by susceptible people, such as health care workers, with focus on individual outcomes. We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation.
Keywords: COVID-19; SARS-CoV-2; masks; pandemic.
Conflict of interest statement
The authors declare no competing interest.