The Utility of Masks as Protection Against Viral Respiratory Illnesses in Healthcare Workers

The COVID-19 pandemic is sweeping the globe, increasing the mortality and morbidity rates in areas that are experiencing outbreaks and putting excess pressure on healthcare systems. Healthcare workers (HCWs) have risen to the challenge of caring for those infected during the COVID-19 pandemic, putting themselves in high-risk situations. Current Center for Disease Control and Prevention (CDC) guidelines require HCWs to follow isolation precautions based on transmission routes to protect themselves from becoming infected. For COVID19, the recommendation for HCWs is continuous wearing of a surgical mask during a shift and donning an N95 mask while in direct contact with patients who have an active COVID-19 infection. Unfortunately, despite proper PPE utilization and CDC guidelines, HCWs represent a small portion of the total number of people hospitalized due to COVID-19. The purpose of this literature review is to identify evidence supporting CDC guidelines directed at protecting HCWs from respiratory viral infection and any gaps that may exist which may leave HCWs vulnerable. This literature review took place from September of 2020 to March of 2021, assessed 54 total studies, and identified 16 studies meeting requirements for this review. High level evidence from quasi-experimental studies looking at filtration efficacy of different masks and randomized control trials comparing rates of viral symptoms and viral infections in HCWs wearing different masks were prioritized for this review. While the evidence is inconsistent it still supported current CDC guidelines. The N95 masks showed better filtration efficiency at all particle sizes when compared to all other masks while surgical masks demonstrated better filtration efficiency at all particle sizes when compared to a variety of cloth masks. The N95 masks also reduced rates of viral symptoms and viral infections when compared to surgical masks while surgical masks reduced rates of viral symptoms and viral infections when compared to a variety of cloth masks. Ultimately, N95 and surgical mask use in healthcare settings to provide respiratory protection to HCWs is supported by current evidence while use of cloth masks of a variety of materials in a healthcare setting is grossly ineffective at providing respiratory protection for HCWs. This review recommends enhancing current CDC transmission-based precaution guidelines by including requirements for patients to don surgical masks while under investigation for respiratory viral infections or with active respiratory viral infections. Including language within the guidelines to require HCWs to don N95 masks during identified aerosol generating procedures is also recommended to maximize protection against small respiratory aerosols. Ongoing HCW education regarding the effectiveness of masks and the current evidence supporting mask use in different situations is also recommended. Lastly, ongoing research into the effectiveness of masks, targeted mask us, and the impact of fit testing N95 masks is highly recommended