Risk and protective factors for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection among healthcare workers: A test-negative case–control study in Québec, Canada

Abstract

Objectives: In Quebec, Canada, we evaluated the risk of SARS-CoV-2 infection associated with: 1) the demographic and employment characteristics among healthcare workers (HCWs); and 2) the workplace and household exposures and the infection prevention and control (IPC) measures among patient-facing HCWs. Design: Test-negative case-control study Setting: Provincial health system Participants: HCWs with PCR-confirmed COVID-19 diagnosed between November 15, 2020 and May 29, 2021 (cases) were compared to HCWs with compatible symptoms but testing negative during the same period (controls). Methods: Adjusted odds ratios (aOR) of infection were estimated using regression logistic models evaluating demographic and employment characteristics (all 4919 cases and 4803 controls) or household and workplace exposures and IPC measures (2046 patient-facing cases and 1362 controls). Results: COVID-19 risk was associated with working as housekeeping staff (aOR=3.6), patient support assistants (aOR=1.9) and nursing staff (aOR=1.4) (compared to administrative staff), being unexperienced (aOR=1.5) and working in private seniors’ homes (aOR=2.1) and long-term care (aOR=1.5) facilities (compared to acute-care hospitals). Among patient-facing HCWs, exposure to a household contact was reported by 9% of cases and was associated with the highest risk of infection (aOR=7.8). Most infections were likely attributable to the more frequent exposure to infected patients (aOR=2.7) and coworkers (aOR=2.2). Wearing a N95 respirator during contacts with COVID-19 patients (aOR=0.7) and vaccination (aOR=0.2) were the measures associated with a risk reduction. Conclusion: In the context of the ever-changing SARS-CoV-2 virus with increasing transmissibility, measures to ensure HCWs’ protection, including vaccination and respiratory protection, and patients’ safety will need ongoing evaluation.

Risk of Testing Positive for COVID-19 among Healthcare and Healthcare-Related Workers

“…To the best of our knowledge, there are limited published data evaluating the specific impact of job roles in healthcare settings on the risk of testing positive for COVID-19, and the findings are heterogeneous. Two studies conducted in Germany reported an increased risk of testing positive for nurses and physicians compared to non-patient care occupations [ 4 , 21 ]. Additionally, a separate study indicated a higher risk among administrative personnel [ 22 ].…”

SARS-CoV-2 infection among healthcare workers: the role of occupational and household exposures during the first three pandemic waves in Quebec, Canada

“…Akinbami et al reported higher seroprevalence at the end of the first wave among staff in nursing homes (13%) than in hospitals (5%), 7 while our previous study in Quebec showed that working in LTCF or private seniors' homes increased the risk of SARS-CoV-2 infection compared to ACH. 10 Conversely, the relatively higher proportion of HCWs with householdacquired infections among ACH workers might be a reflection of this lower workplace risk.…”

“…The study population has been described elsewhere. 9,10 In summary, a survey was conducted among HCWs with a PCR-confirmed SARS-CoV-2 infection diagnosed between March 1, 2020, and May 31, 2021, excluding June 14 to July 11, 2020, due to the low incidence during that period. Vaccination of HCWs started on December 14, 2020.…”