Universal Use of N95s in Healthcare Settings when Community Covid-19 Rates are High.

CDC now recommends N95 respirators for all providers seeing patients with possible or confirmed Covid-19. We suggest, however, that N95s may be just as important for the care of patients without suspected Covid-19 when community incidence rates are high. This is because SARS-CoV-2 is most contagious before symptom onset. Ironically, by the time patients are sick enough to be admitted to hospital with Covid-19 they tend to be less contagious. The greatest threat of transmission in healthcare facilities may therefore be patients and healthcare workers with early occult infection. N95s' superior fit and filtration provide superior exposure protection for healthcare providers seeing patients with early undiagnosed infection and superior source control to protect patients from healthcare workers with early undiagnosed infection. The probability of occult infection in patients and healthcare workers is greatest when community incidence rates are high. Universal use of N95s may help decrease nosocomial transmission at such times.