Seroprevalence of antibodies to SARS-CoV-2 in healthcare workers: a cross-sectional study

Joseph E Ebinger; Gregory J Botwin; Christine M Albert; Mona Alotaibi; Moshe Arditi; Anders H Berg; Aleksandra Binek; Patrick Botting; Justyna Fert-Bober; Jane C Figueiredo; Jonathan D Grein; Wohaib Hasan; Mir Henglin; Shehnaz K Hussain; Mohit Jain; Sandy Joung; Michael Karin; Elizabeth H Kim; Dalin Li; Yunxian Liu; Eric Luong; Dermot P B McGovern; Akil Merchant; Noah Merin; Peggy B Miles; Margo Minissian; Trevor Trung Nguyen; Koen Raedschelders; Mohamad A Rashid; Celine E Riera; Richard V Riggs; Sonia Sharma; Sarah Sternbach; Nancy Sun; Warren G Tourtellotte; Jennifer E Van Eyk; Kimia Sobhani; Jonathan G Braun; Susan Cheng

doi:10.1136/bmjopen-2020-043584

Seroprevalence of antibodies to SARS-CoV-2 in healthcare workers: a cross-sectional study

BMJ Open. 2021 Feb 12;11(2):e043584. doi: 10.1136/bmjopen-2020-043584.

Authors

Joseph E Ebinger^{1

2}, Gregory J Botwin³, Christine M Albert^{1

2}, Mona Alotaibi⁴, Moshe Arditi^{2

5

6}, Anders H Berg⁷, Aleksandra Binek⁸, Patrick Botting^{1

2}, Justyna Fert-Bober², Jane C Figueiredo⁹, Jonathan D Grein^{10

11}, Wohaib Hasan^{7

12}, Mir Henglin^{1

2}, Shehnaz K Hussain¹³, Mohit Jain¹⁴, Sandy Joung^{1

2}, Michael Karin¹⁵, Elizabeth H Kim^{1

2}, Dalin Li³, Yunxian Liu^{1

2}, Eric Luong^{1

2}, Dermot P B McGovern³, Akil Merchant¹⁰, Noah Merin¹⁶, Peggy B Miles¹⁷, Margo Minissian^{1

2

18}, Trevor Trung Nguyen^{1

2}, Koen Raedschelders^{1

2

8}, Mohamad A Rashid^{1

2}, Celine E Riera^{19

20}, Richard V Riggs²¹, Sonia Sharma²², Sarah Sternbach², Nancy Sun^{1

2}, Warren G Tourtellotte^{7

12}, Jennifer E Van Eyk^{1

8

23}, Kimia Sobhani²⁴, Jonathan G Braun²⁴, Susan Cheng^{25

2

23}

Affiliations

¹ Department of Cardiology, Cedars-Sinai Medical Center, Los Angeles, California, USA.
² Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.
³ F. Widjaja Foundation Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.
⁴ Division of Pulmonary and Critical Care Medicine, University of California, San Diego, La Jolla, California, USA.
⁵ Departments of Pediatrics, Division of Infectious Diseases and Immunology, and Infectious and Immunologic Diseases Research Center (IIDRC), Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA.
⁶ Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
⁷ Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA.
⁸ Advanced Clinical Biosystems Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA.
⁹ Cedars-Sinai Cancer and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA.
¹⁰ Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA.
¹¹ Department of Epidemiology, Cedars-Sinai Medical Center, Los Angeles, California, USA.
¹² Biobank & Translational Research Core Laboratory, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.
¹³ Department of Public Health Sciences and Comprehensive Cancer Center, University of California, Davis, Davis, California, USA.
¹⁴ Department of Medicine and Pharmacology, University of California, San Diego, La Jolla, California, USA.
¹⁵ Department of Pharmacology, University of California San Diego School of Medicine, La Jolla, California, USA.
¹⁶ Department of Internal Medicine, Division of Hematology, Cedars-Sinai Medical Center, Los Angeles, California, USA.
¹⁷ Employee Health Services, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA.
¹⁸ Brawerman Nursing Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.
¹⁹ Center for Neural Science and Medicine, Department of Biomedical Sciences, Board of Governors Regenerative Medicine Institute, Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, California, USA.
²⁰ David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA.
²¹ Chief Medical Officer, Cedars-Sinai Medical Center, Los Angeles, California, USA.
²² La Jolla Institute for Allergy and Immunology, La Jolla, California, USA.
²³ Barbra Streisand Women's Heart Center, Cedars-Sinai Medical Center, Los Angeles, California, USA.
²⁴ Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA susan.cheng@cshs.org Jonathan.Braun2@cshs.org Kimia.Sobhani@cshs.org.
²⁵ Department of Cardiology, Cedars-Sinai Medical Center, Los Angeles, California, USA susan.cheng@cshs.org Jonathan.Braun2@cshs.org Kimia.Sobhani@cshs.org.

Abstract

Objective: We sought to determine the extent of SARS-CoV-2 seroprevalence and the factors associated with seroprevalence across a diverse cohort of healthcare workers.

Design: Observational cohort study of healthcare workers, including SARS-CoV-2 serology testing and participant questionnaires.

Settings: A multisite healthcare delivery system located in Los Angeles County.

Participants: A diverse and unselected population of adults (n=6062) employed in a multisite healthcare delivery system located in Los Angeles County, including individuals with direct patient contact and others with non-patient-oriented work functions.

Main outcomes: Using Bayesian and multivariate analyses, we estimated seroprevalence and factors associated with seropositivity and antibody levels, including pre-existing demographic and clinical characteristics; potential COVID-19 illness-related exposures; and symptoms consistent with COVID-19 infection.

Results: We observed a seroprevalence rate of 4.1%, with anosmia as the most prominently associated self-reported symptom (OR 11.04, p<0.001) in addition to fever (OR 2.02, p=0.002) and myalgias (OR 1.65, p=0.035). After adjusting for potential confounders, seroprevalence was also associated with Hispanic ethnicity (OR 1.98, p=0.001) and African-American race (OR 2.02, p=0.027) as well as contact with a COVID-19-diagnosed individual in the household (OR 5.73, p<0.001) or clinical work setting (OR 1.76, p=0.002). Importantly, African-American race and Hispanic ethnicity were associated with antibody positivity even after adjusting for personal COVID-19 diagnosis status, suggesting the contribution of unmeasured structural or societal factors.

Conclusion and relevance: The demographic factors associated with SARS-CoV-2 seroprevalence among our healthcare workers underscore the importance of exposure sources beyond the workplace. The size and diversity of our study population, combined with robust survey and modelling techniques, provide a vibrant picture of the demographic factors, exposures and symptoms that can identify individuals with susceptibility as well as potential to mount an immune response to COVID-19.

Keywords: COVID-19; infectious diseases; public health.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Adult
Antibodies, Viral / blood*
Bayes Theorem
COVID-19 / diagnosis*
COVID-19 / immunology
COVID-19 Serological Testing
Cohort Studies
Cross-Sectional Studies
Female
Health Personnel*
Humans
Los Angeles / epidemiology
Male
Middle Aged
SARS-CoV-2 / immunology
Seroepidemiologic Studies*

Substances

Antibodies, Viral

Abstract

Publication types

MeSH terms

Substances

Grants and funding