Dörr et al.: COVID mask study Health care workers (HCWs) shows BLUE surgical masks in Hospital settings far more ineffective & POSITIVE home contact NOT workplace, drives INFECTION (OR 7.79, <0.001)

Risk of infection with POSITIVE home contact, univariate analysis OR 8.82, 95% CI 7.09 - 11.0), multivariate analyses OR 7.79, 95% CI 5.98 - 10.15), bot p< 0.001

SOURCE

In this study, SARS-CoV-2 positivity in HCWs was associated with cumulative COVID-19 patient exposure. The odds of being SARS-CoV-2–positive were reduced by more than 40% in individuals using respirators irrespective of cumulative exposure, even after adjusting for multiple work- and nonwork-related covariables.

For those exposed to patients, positivity was 21% for HCWs using respirator masks and 35% for those using surgical/mixed masks (OR, 0.49; 95% CI, 0.39-0.61), showing an increase for surgical/mixed mask users (OR, 1.21; 95% CI, 1.15-1.28) and respirator mask users (OR, 1.15; 95% CI, 1.05-1.27) across categories of patient exposure (Figure).’