(See the Major Article by Landry et al on pages 199–207.)

The coronavirus disease 2019 (COVID-19) pandemic has focused an intense spotlight on respiratory precautions for healthcare workers managing patients with respiratory viral infections. Prevailing wisdom before the pandemic was that most respiratory viruses are transmitted by large respiratory droplets and fomites. These droplets were believed to have a carrying radius of 3–6 feet before rapidly falling to the ground by virtue of gravity. Surgical masks were presumed to provide adequate protection in most situations by providing a barrier between patients’ emissions and the mucous membranes of providers’ mouths and noses.

Notwithstanding this framework, the United States Centers for Disease Control and Prevention’s (CDC) infection control guidelines include a hodgepodge of different personal protective equipment recommendations for different respiratory viruses [1]. These span the gamut from respirators, eye protection, gowns, and gloves to care for patients with emerging pathogens such as Middle East Respiratory Syndrome (MERS), avian influenza, and now, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); surgical masks alone to care for patients with influenza; gloves and gowns alone without masks or eye protection to care for patients with respiratory syncytial virus (RSV); and nothing at all to care for immunocompetent adults with parainfluenza.

This curious mix of recommendations appears to be the product of a handful of studies conducted predominantly in the 1980s and 1990s that evaluated the additive benefit of one or more of these precautions against one of these viruses, mostly RSV. None of the cited studies compared infection rates between viruses or provided evidence why one virus should be treated differently from another. Many of the source studies only reported on nosocomial infection rates in patients but did not consider infections in healthcare workers. And almost all the studies focused on pediatric populations. The suitability of these studies to support current infection control recommendations is dubious.

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