Epidemiology of and Risk Factors for Coronavirus Infection in Health Care Workers; A Living Rapid Review

Background: Health care workers (HCWs) are at risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Purpose: To examine the burden of SARS-CoV-2, SARS-CoV-1, and Middle East respiratory syndrome (MERS)-CoV on HCWs and risk factors for infection, using rapid and living review methods. Data Sources: Multiple electronic databases, including the WHO database of publications on coronavirus disease and the medRxiv preprint server (2003 through 27 March 2020, with ongoing surveillance through 24 April 2020), and reference lists. Study Selection: Studies published in any language reporting incidence of or outcomes associated with coronavirus infections in HCWs and studies on the association between risk factors (demographic characteristics, role, exposures, environmental and administrative factors, and personal protective equipment [PPE] use) and HCW infections. New evidence will be incorporated on an ongoing basis by using living review methods. Data Extraction: One reviewer abstracted data and assessed methodological limitations; verification was done by a second reviewer. Data Synthesis: 64 studies met inclusion criteria; 43 studies addressed burden of HCW infections (15 on SARS-CoV-2), and 34 studies addressed risk factors (3 on SARS-CoV-2). Health care workers accounted for a significant proportion of coronavirus infections and may experience particularly high infection incidence after unprotected exposures. Illness severity was lower than in non-HCWs. Depression, anxiety, and psychological distress were common in HCWs during the coronavirus disease 2019 outbreak. The strongest evidence on risk factors was on PPE use and decreased infection risk. The association was most consistent for masks but was also observed for gloves, gowns, eye protection, and handwashing; evidence suggested a dose- response relationship. No study evaluated PPE reuse. Certain exposures (such as involvement in intubations, direct patient contact, or contact with bodily secretions) were associated with increased infection risk. Infection control training was associated with decreased risk. Limitation: There were few studies on risk factors for SARSCoV- 2, the studies had methodological limitations, and streamlined rapid review methods were used. Conclusion: Health care workers experience significant burdens from coronavirus infections, including SARS-CoV-2. Use of PPE and infection control training are associated with decreased infection risk, and certain exposures are associated with increased risk.