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 Güsewell, 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 & Philipp Kohler


Protecting healthcare workers (HCW) 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 June 22 and August 15 2020, HCW 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 4'664 HCW 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 HCW. 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, Güsewell 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, Flury B B, Besold U, Fehr J, Kuster S P, McGeer A, Risch L, Schlegel M, Friedl A, Vernazza P, Kohler P. Non-occupational and occupational factors associated with specific SARS-CoV-2 antibodies among hospital workers - A multicentre cross-sectional study. Clin Microbiol Infect 2021;.
type journal paper/review (English)
date of publishing 18-05-2021
journal title Clin Microbiol Infect
ISSN electronic 1469-0691
PubMed 34020033
DOI 10.1016/j.cmi.2021.05.014