SARS-CoV-2 Infection in Health Workers: Analysis from Verona SIEROEPID Study during the Pre-Vaccination Era.
Stefano Porru, Maria Grazia Lourdes Monaco, Angela Carta, Gianluca Spiteri, Marco Parpaiola, Andrea Battaggia, Giulia Galligioni, Beatrice Ferrazzi, Giuliana Lo Cascio, Davide Gibellini, Angelo Peretti, Martina Brutti, Stefano Tardivo, Giovanna Ghirlanda, Giuseppe Verlato, Stefania Gaino, Denise Peserico, Antonella Bassi, Giuseppe Lippi
Author Information
Stefano Porru: Section of Occupational Medicine, Department of Diagnostics and Public Health, University of Verona, 37134 Verona, Italy.
Maria Grazia Lourdes Monaco: Clinical Unit of Occupational Medicine, University Hospital of Verona, 37134 Verona, Italy. ORCID
Angela Carta: Section of Occupational Medicine, Department of Diagnostics and Public Health, University of Verona, 37134 Verona, Italy. ORCID
Gianluca Spiteri: Clinical Unit of Occupational Medicine, University Hospital of Verona, 37134 Verona, Italy. ORCID
Marco Parpaiola: Postgraduate School of Occupational Medicine, University of Verona, 37134 Verona, Italy.
Andrea Battaggia: Postgraduate School of Occupational Medicine, University of Verona, 37134 Verona, Italy.
Giulia Galligioni: Postgraduate School of Occupational Medicine, University of Verona, 37134 Verona, Italy.
Beatrice Ferrazzi: Postgraduate School of Occupational Medicine, University of Verona, 37134 Verona, Italy.
Giuliana Lo Cascio: Local Heath Authority of Piacenza, 29121 Piacenza, Italy.
Davide Gibellini: Section of Microbiology, Department of Diagnostics and Public Health, University of Verona, 37134 Verona, Italy.
Angelo Peretti: Unit of Microbiology and Virology, University Hospital of Verona, 37134 Verona, Italy.
Martina Brutti: Unit of Microbiology and Virology, University Hospital of Verona, 37134 Verona, Italy.
Stefano Tardivo: Section of Hygiene, Department of Diagnostics and Public Health, University of Verona, 37134 Verona, Italy. ORCID
Giovanna Ghirlanda: Medical Direction, University Hospital of Verona, 37134 Verona, Italy.
Giuseppe Verlato: Unit of Epidemiology and Medical Statistics, Department of Diagnostics and Public Health, University of Verona, 37134 Verona, Italy. ORCID
Stefania Gaino: Laboratory of Clinical Chemistry and Hematology, University Hospital of Verona, 37134 Verona, Italy.
Denise Peserico: Section of Clinical Biochemistry, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy.
Antonella Bassi: Laboratory of Clinical Chemistry and Hematology, University Hospital of Verona, 37134 Verona, Italy. ORCID
Giuseppe Lippi: Laboratory of Clinical Chemistry and Hematology, University Hospital of Verona, 37134 Verona, Italy. ORCID
BACKGROUND: To report the baseline phase of the SIEROEPID study on SARS-CoV-2 infection seroprevalence among health workers at the University Hospital of Verona, Italy, between spring and fall 2020; to compare performances of several laboratory tests for SARS-CoV-2 antibody detection. METHODS: 5299 voluntary health workers were enrolled from 28 April 2020 to 28 July 2020 to assess immunological response to SARS-CoV-2 infection throughout IgM, IgG and IgA serum levels titration by four laboratory tests. Association of antibody titre with several demographic variables, swab tests and performance tests (sensitivity, specificity, and agreement) were statistically analyzed. RESULTS: The overall seroprevalence was 6%, considering either IgG and IgM, and 4.8% considering IgG. Working in COVID-19 Units was not associated with a statistically significant increase in the number of infected workers. Cohen's kappa of agreement between MaglumiTM and VivaDiagTM was quite good when considering IgG only (Cohen's kappa = 78.1%, 95% CI 74.0-82.0%), but was lower considering IgM (Cohen's kappa = 13.3%, 95% CI 7.8-18.7%). CONCLUSION: The large sample size with high participation (84.7%), the biobank and the longitudinal design were significant achievements, offering a baseline dataset as the benchmark for risk assessment, health surveillance and management of SARS-CoV-2 infection for the hospital workforce, especially considering the ongoing vaccination campaign. Study results support the national regulator guidelines on using swabs for SARS-CoV-2 screening with health workers and using the serological tests to contribute to the epidemiological assessment of the spread of the virus.
