Widespread use of face masks in public may slow the spread of SARS CoV-2: an ecological study

Chris Kenyon

Even if we discount the evidence of airborne transmission, face masks could play a 98 major role in reducing droplet and possibly contact (via reduced digital-oral 99 interactions) transmission. The second type of evidence is that from epidemiological 100 studies showing that masks do provide this protective effect. One systematic review 101 on the efficacy of face masks to prevent influenza, found evidence that face masks 102 were effective in preventing the transmission to others and weaker evidence that 103 they prevented influenza acquisition [14] . Likewise, a systematic review and 104 metanalysis in health care workers found that mask wearing was associated with a 105 lower incidence of clinical respiratory infections [15] . A Cochrane review of different 106 physical measures to prevent the acquisition of respiratory viruses found face masks 107 to be the most effective of all measures investigated -including social distancing 108