Author:
Kohler Philipp,Dörr Tamara,Friedl Andrée,Stocker Reto,Vuichard Danielle,Kuster Stefan P.,Kahlert Christian R.,Besold Ulrike,Betschon Elsbeth,Brucher Angela,Cusini Alexia,Friedl Andrée,Goppel Stephan,Grässli Fabian,Kahlert Christian R.,Keller Joelle,Kessler Simone,Kohler Philipp,Kuster Stefan P.,Leal Onicio,Lemmenmeier Eva,McGeer Allison,Kleeb Dorette Meier,Möller Elisabeth,Möller J. Carsten,Müller Maja F.,Musa Vaxhid,Ortner Manuela,Rieder Philip,Risch Lorenz,Ruetti Markus,Schlegel Matthias,Schmid Hans-Ruedi,Stocker Reto,Vernazza Pietro,von Kietzell Matthias,Vuichard-Gysin Danielle,Wiggli Benedikt,
Abstract
Abstract
Background
Few studies have assessed whether the increased SARS-CoV-2 risk of healthcare workers (HCW) is carried on to their household contacts. Within a prospective HCW cohort, we assessed the SARS-CoV-2 risk of household contacts of HCW depending on the HCWs cumulative exposure to COVID-19 patients and identified factors influencing this association.
Methods
HCW aged ≥ 16 years from nine Swiss healthcare networks participated. HCW without any household contacts were excluded. For HCW, cumulative patient exposure (number of COVID-19 patient contacts times average contact duration during a 12-month follow-up) was calculated. During follow-up, HCW reported SARS-CoV-2 nasopharyngeal swab results and positive swab results of their household contacts. We used multivariable logistic regression to identify variables associated with SARS-CoV-2 household positivity.
Results
Of 2406 HCW, 466 (19%) reported ≥ 1 SARS-CoV-2 positive household. In multivariable analysis, patient exposure of HCW (adjusted OR [aOR] 1.08 per category, 95% CI 1.04–1.12), household size (aOR 1.53 per household member, 95% CI 1.35–1.73) and having children (aOR 0.70, 95% CI 0.53–0.94) remained associated with household positivity. Vaccinated HCW had a lower risk (aOR 0.54, 95% CI 0.38–0.77) of reporting a positive contact, as were those using respirator masks in contact with COVID-19 patients (aOR 0.65, 95% CI 0.49–0.86). Among vaccinated HCW, delayed first vaccination was associated with increased household SARS-CoV-2 positivity (aOR 1.14 per month, 95% CI 1.08–1.21).
Conclusions
SARS-CoV-2 positivity in household contacts of HCW increases with higher cumulative COVID-19 patient exposure of HCWs. Measures reducing the SARS-CoV-2 risk in HCW might indirectly reduce the infection risk of their households.
Funder
Swiss National Sciences Foundation
Federal Office of Public Health
Health Department of the Canton of St. Gallen
Research fund of the Cantonal Hospital of St. Gallen
Publisher
Springer Science and Business Media LLC
Subject
Pharmacology (medical),Infectious Diseases,Microbiology (medical),Public Health, Environmental and Occupational Health