Objectives. Healthcare 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.
Methods. We 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.
Results. A 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.
Conclusions. 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.