Kantonsspital St.Gallen

Non-occupational and occupational factors associated with specific SARS-CoV-2 antibodies among hospital workers - A multicentre cross-sectional study

Christian R. Kahlert, Raphael Persi, Sabine Guesewell, Thomas Egger, Onicio B Leal-Neto, Johannes Sumer, Domenica Flury, Angela Brucher, Eva Lemmenmeier, J Carsten Möller, Philip Rieder, Reto Stocker, Danielle Vuichard-Gysin, Benedikt Wiggli, Werner Albrich, Baharak Babouee Flury, Ulrike Besold, Jan Fehr, Stefan P Kuster, Allison McGeer, Lorenz Risch, Matthias Schlegel, Andrée Friedl, Pietro Vernazza & Fariba Abbassi


Protecting healthcare workers (HCWs) from coronavirus disease-19 (COVID-19) is critical to preserve the functioning of healthcare systems. We therefore assessed seroprevalence and identified risk factors for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) seropositivity in this population.

Between 22 June 22 and 15 August 2020, HCWs from institutions in northern/eastern Switzerland were screened for SARS-CoV-2 antibodies. We recorded baseline characteristics, non-occupational and occupational risk factors. We used pairwise tests of associations and multivariable logistic regression to identify factors associated with seropositivity.

Among 4664 HCWs from 23 healthcare facilities, 139 (3%) were seropositive. Non-occupational exposures independently associated with seropositivity were contact with a COVID-19-positive household (adjusted OR 59, 95% CI 33-106), stay in a COVID-19 hotspot (aOR 2.3, 95% CI 1.2-4.2) and male sex (aOR 1.9, 95% CI 1.1-3.1). Blood group 0 vs. non-0 (aOR 0.5, 95% CI 0.3-0.8), active smoking (aOR 0.4, 95% CI 0.2-0.7), living with children <12 years (aOR 0.3, 95% CI 0.2-0.6) and being a physician (aOR 0.2, 95% CI 0.1-0.5) were associated with decreased risk. Other occupational risk factors were close contact to COVID-19 patients (aOR 2.7, 95% CI 1.4-5.4), exposure to COVID-19-positive co-workers (aOR 1.9, 95% CI 1.1-2.9), poor knowledge of standard hygiene precautions (aOR 1.9, 95% CI 1.2-2.9) and frequent visits to the hospital canteen (aOR 2.3, 95% CI 1.4-3.8).

Living with COVID-19-positive households showed the strongest association with SARS-CoV-2 seropositivity. We identified several potentially modifiable work-related risk factors, which might allow mitigation of the COVID-19 risk among HCWs. The lower risk among those living with children, even after correction for multiple confounders, is remarkable and merits further study.
citation Kahlert C R, Persi R, guesewell s, Egger T, Leal-Neto O B, Sumer J, Flury D, Brucher A, Lemmenmeier E, Möller J C, Rieder P, Stocker R, Vuichard-Gysin D, Wiggli B, albrich w, Babouee Flury B, Besold U, Fehr J, Kuster S P, McGeer A, Risch L, Schlegel M, Friedl A, vernazza p, Abbassi F. Non-occupational and occupational factors associated with specific SARS-CoV-2 antibodies among hospital workers - A multicentre cross-sectional study. Clin Microbiol Infect 2021; 27:1336-1344.
type journal paper/review (English)
date of publishing 19-05-2021
journal title Clin Microbiol Infect (27/9)
ISSN electronic 1469-0691
pages 1336-1344
PubMed 34020033
DOI 10.1016/j.cmi.2021.05.014