November 21, 2020

Background: Face masks can reduce transmission of respiratory viruses by both being a potential physical barrier and by reducing droplet transmission.  Additionally, the presence of a mask reduces the users frequency of touching their face which may also reduce transmission.  Despite strong, consistent public health messaging about the utility of wearing masks, their use continues to be debated. Both the CDC and WHO strongly recommend the use of masks as a means of source control, but the WHO acknowledges the lack of robust evidence in healthy persons.