SARS-CoV-2 Exposures of Healthcare Workers from Primary Care, Long-Term Care Facilities and Hospitals: A Nationwide Matched Case-Control Study

ObjectivesHealthcare workers (HCWs) are at higher risk of contracting coronavirus disease-19 (COVID-19) than the general population. This study assessed the roles of various exposures and personal protective equipment (PPE) use on that risk for HCWs working in primary care, long-term-care facilities (LTCFs) or hospitals.MethodsWe conducted a matched case-control (1:1) study (10 April–9 July 2021). Cases (HCWs with confirmed COVID-19) and controls (HCWs without any COVID-19-positive test or symptoms) recruited by email were invited to complete an online questionnaire on their exposures and PPE use. Questions covered the 10 days preceding symptom onset for cases (or testing if asymptomatic) or inclusion for controls.ResultsA total of 4152 matched cases and controls were included. The multivariable conditional logistic regression analysis retained exposure to an infected person outside work (adjusted odds ratio, 19.9 [95% confidence intervaI, 12.4–31.9]), an infected colleague (2.26 [1.53–3.33]) or COVID-19 patients (2.37 [1.66–3.40]), as independent predictors of COVID-19 in HCWs, while partial or complete immunization was protective. Eye protection (0.57 [0.37–0.87]) and wearing a gown (0.58 [0.34–0.97]) during COVID-19 patient care were protective, while wearing an apron slightly increased the risk of infection (1.47 [1.00–2.18]). N95-respirator protection was comparable to that of surgical masks. Results were consistent across healthcare-facility categories.ConclusionsHCWs 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.