[Rapid review of the use of community-wide surgical masks and acute respiratory infections].

Stern, Dalia; López-Olmedo, Nancy; Pérez-Ferrer, Carolina; González-Morales, Romina; Canto-Osorio, Francisco; Barrientos-Gutiérrez, Tonatiuh

OBJECTIVE To assess the effectiveness of using surgical masks in community settings to reduce the probability of infection by SARS-CoV-2 or other acute viral respiratory infection, compared to not using surgical masks. MATERIALS AND METHODS We followed the Cochrane rapid review methodology. The search strategy encompasses one academic database and pre-prints until April 1, 2020. Titles and abstracts were reviewed by one investigator. The full text review was divided among three researchers. The results were synthesized in a narrative way. RESULTS 713 manuscripts were identified, of which 21 met the inclusion criteria. Of six systematic reviews, four found no reduction in the probability of transmission. Experimental home studies found no differences in the probability of contagion associated with the use of mouth masks. Only one modeling study estimated a 20% reduction in the incidence of acute respiratory disease, assuming that 10 to 50% of the population use the surgical masks correctly. CONCLUSIONS The scientific evidence is inconclusive to recommend or discourage the use of surgical masks at the population level. Considering the potential negative effects, official recommendations should await for the results of natural experiments currently occurring in countries that have recommended the use of face masks at the population level.