TY - JOUR T1 - SARS-CoV-2 seroprevalence in health care workers from 10 hospitals in Quebec, Canada: a cross-sectional study JF - Canadian Medical Association Journal JO - CMAJ SP - E1868 LP - E1877 DO - 10.1503/cmaj.202783 VL - 193 IS - 49 AU - Nicholas Brousseau AU - Laurianne Morin AU - Manale Ouakki AU - Patrice Savard AU - Caroline Quach AU - Yves Longtin AU - Matthew P. Cheng AU - Alex Carignan AU - Simon F. Dufresne AU - Jean-Michel Leduc AU - Christian Lavallée AU - Nicolas Gauthier AU - Julie Bestman-Smith AU - Maria-Jesus Arrieta AU - Magued Ishak AU - Simon Lévesque AU - Philippe Martin AU - Gaston De Serres Y1 - 2021/12/13 UR - http://www.cmaj.ca/content/193/49/E1868.abstract N2 - Background: The COVID-19 pandemic has disproportionately affected health care workers. We sought to estimate SARS-CoV-2 seroprevalence among hospital health care workers in Quebec, Canada, after the first wave of the pandemic and to explore factors associated with SARS-CoV-2 seropositivity.Methods: Between July 6 and Sept. 24, 2020, we enrolled health care workers from 10 hospitals, including 8 from a region with a high incidence of COVID-19 (the Montréal area) and 2 from low-incidence regions of Quebec. Eligible health care workers were physicians, nurses, orderlies and cleaning staff working in 4 types of care units (emergency department, intensive care unit, COVID-19 inpatient unit and non-COVID-19 inpatient unit). Participants completed a questionnaire and underwent SARS-CoV-2 serology testing. We identified factors independently associated with higher seroprevalence.Results: Among 2056 enrolled health care workers, 241 (11.7%) had positive SARS-CoV-2 serology. Of these, 171 (71.0%) had been previously diagnosed with COVID-19. Seroprevalence varied among hospitals, from 2.4% to 3.7% in low-incidence regions to 17.9% to 32.0% in hospitals with outbreaks involving 5 or more health care workers. Higher seroprevalence was associated with working in a hospital where outbreaks occurred (adjusted prevalence ratio 4.16, 95% confidence interval [CI] 2.63–6.57), being a nurse or nursing assistant (adjusted prevalence ratio 1.34, 95% CI 1.03–1.74) or an orderly (adjusted prevalence ratio 1.49, 95% CI 1.12–1.97), and Black or Hispanic ethnicity (adjusted prevalence ratio 1.41, 95% CI 1.13–1.76). Lower seroprevalence was associated with working in the intensive care unit (adjusted prevalence ratio 0.47, 95% CI 0.30–0.71) or the emergency department (adjusted prevalence ratio 0.61, 95% CI 0.39–0.98).Interpretation: Health care workers in Quebec hospitals were at high risk of SARS-CoV-2 infection, particularly in outbreak settings. More work is needed to better understand SARS-CoV-2 transmission dynamics in health care settings. ER -