SARS-CoV-2 exposures of healthcare workers from primary care, long-term care facilities and hospitals: a nationwide matched case-control study

Objectives: This study assessed the roles of various exposures and personal protective equipment (PPE) use on healthcare workers' (HCWs) risk of COVID-19 working in primary care, long-term-care facilities or hospitals. Methods: We conducted a matched case-control (1:1) study (10 April through 9 July 2021). Cases (HCWs with confirmed COVID-19) and controls (HCWs without any COVID-19-positive test or symptoms) were invited by E-mail to complete an online questionnaire on their exposures and PPE use over the 10-day period preceding inclusion. Risk factors were analysed using multivariable conditional logistic regression. Results: A total of 2076 cases and 2076 matched controls were included. The analysis retained exposure to an infected person outside work (adjusted OR 19.9 (95% CI, 12.4-31.9)), an infected colleague (OR 2.26 (95% CI, 1.53-3.33)) or COVID-19 patients (OR 2.37 (95% CI, 1.66-3.40)), as independent predictors of COVID-19 in HCWs, while partial (OR 0.30 (95% CI, 0.22-0.40)) or complete (OR 0.19 (95% CI, 0.14-0.27)) immunisation was protective. Eye protection (OR 0.57 (95% CI, 0.37-0.87)) and wearing a gown (OR 0.58 (95% CI, 0.34-0.97)) for COVID-19 patient care were protective, while wearing an apron slightly increased the risk of infection (OR 1.47 (95% CI, 1.00-2.18)). Protection of N95 respirators and surgical face masks did not differ. Compared to medical professions, being a nurse (OR 3.79 (95% CI, 2.50-5.76)) or a nurse's aide (OR 9.08 (95% CI, 5.30-15.5)) was associated with COVID-19. Results were consistent across all healthcare settings. Discussion: HCWs were more likely to get COVID-19 in their personal sphere than during occupational activities. Our results suggest that eye protection for HCWs during patient care should be actively promoted. (C) 2022 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.