Prevalence and incidence of anti-SARS-CoV-2 antibodies among healthcare workers in Belgian hospitals before vaccination: a prospective cohort study

Objectives To describe prevalence and incidence of anti-SARS-CoV-2 antibodies among Belgian hospital healthcare workers (HCW) in April–December 2020.Design Prospective cohort study. Follow-up was originally planned until September and later extended.Setting Multicentre study, 17 hospitals.Participan...

Full description

Saved in:
Bibliographic Details
Main Authors: Bea Vuylsteke, Natalie Fischer, Kristien Verdonck, Isabelle Thomas, Els Duysburgh, Laure Mortgat, Veronik Hutse, Cyril Barbezange, Leo Heyndrickx, Ines Kabouche, Kevin K Ariën, Isabelle Desombere
Format: Article
Language:English
Published: BMJ Publishing Group 2021-06-01
Series:BMJ Open
Online Access:https://bmjopen.bmj.com/content/11/6/e050824.full
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1846162876533833728
author Bea Vuylsteke
Natalie Fischer
Kristien Verdonck
Isabelle Thomas
Els Duysburgh
Laure Mortgat
Veronik Hutse
Cyril Barbezange
Leo Heyndrickx
Ines Kabouche
Kevin K Ariën
Isabelle Desombere
author_facet Bea Vuylsteke
Natalie Fischer
Kristien Verdonck
Isabelle Thomas
Els Duysburgh
Laure Mortgat
Veronik Hutse
Cyril Barbezange
Leo Heyndrickx
Ines Kabouche
Kevin K Ariën
Isabelle Desombere
author_sort Bea Vuylsteke
collection DOAJ
description Objectives To describe prevalence and incidence of anti-SARS-CoV-2 antibodies among Belgian hospital healthcare workers (HCW) in April–December 2020.Design Prospective cohort study. Follow-up was originally planned until September and later extended.Setting Multicentre study, 17 hospitals.Participants 50 HCW were randomly selected per hospital. HCW employed beyond the end of the study and whose profession involved contact with patients were eligible. 850 HCW entered the study in April–May 2020, 673 HCW (79%) attended the September visit and 308 (36%) the December visit.Outcome measures A semiquantitative ELISA was used to detect IgG against SARS-CoV-2 in serum (Euroimmun) at 10 time points. In seropositive samples, neutralising antibodies were measured using a virus neutralisation test. Real-time reverse transcription PCR (RT-qPCR) was performed to detect SARS-CoV-2 on nasopharyngeal swabs. Participant characteristics and the presence of symptoms were collected via an online questionnaire.Results Among all participants, 80% were women, 60% nurses and 21% physicians. Median age was 40 years. The seroprevalence remained relatively stable from April (7.7% (95% CI: 4.8% to 12.1%) to September (8.2% (95% CI: 5.7% to 11.6%)) and increased thereafter, reaching 19.7% (95% CI: 12.0% to 30.6%) in December 2020. 76 of 778 initially seronegative participants seroconverted during the follow-up (incidence: 205/1000 person-years). Among all seropositive individuals, 118/148 (80%) had a positive neutralisation test, 83/147 (56%) presented or reported a positive RT-qPCR, and 130/147 (88%) reported COVID-19-compatible symptoms at least once. However, only 46/73 (63%) of the seroconverters presented COVID-19-compatible symptoms in the month prior to seroconversion.Conclusions The seroprevalence among hospital HCW was slightly higher than that of the general Belgian population but followed a similar evolution, suggesting that infection prevention and control measures were effective and should be strictly maintained. After two SARS-CoV-2 waves, 80% of HCW remained seronegative, justifying their prioritisation in the vaccination strategy.Trial registration number NCT04373889
format Article
id doaj-art-fd01f8fe1e1f4886beea7acde3da3fab
institution Kabale University
issn 2044-6055
language English
publishDate 2021-06-01
publisher BMJ Publishing Group
record_format Article
series BMJ Open
spelling doaj-art-fd01f8fe1e1f4886beea7acde3da3fab2024-11-20T04:05:07ZengBMJ Publishing GroupBMJ Open2044-60552021-06-0111610.1136/bmjopen-2021-050824Prevalence and incidence of anti-SARS-CoV-2 antibodies among healthcare workers in Belgian hospitals before vaccination: a prospective cohort studyBea Vuylsteke0Natalie Fischer1Kristien Verdonck2Isabelle Thomas3Els Duysburgh4Laure Mortgat5Veronik Hutse6Cyril Barbezange7Leo Heyndrickx8Ines Kabouche9Kevin K Ariën10Isabelle Desombere1116 Public Health, Institute of Tropical Medicine, Antwerpen, Belgium4 Department of Infectious Diseases in Humans, Sciensano, Brussels, BelgiumDepartment of Public Health, Institute of Tropical Medicine, Antwerpen, Belgium4 Department of Infectious Diseases in Humans, Sciensano, Brussels, BelgiumDepartment of Epidemiology and Public Health, Sciensano, Brussels, Belgium1 Department of Epidemiology and Public Health, Sciensano, Brussels, Belgium4 Department of Infectious Diseases in Humans, Sciensano, Brussels, Belgium4 Department of Infectious Diseases in Humans, Sciensano, Brussels, Belgium5 Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium1 Department of Epidemiology and Public Health, Sciensano, Brussels, Belgium5 Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, BelgiumDepartment of Infectious Diseases in Humans, Sciensano, Brussels, BelgiumObjectives To describe prevalence and incidence of anti-SARS-CoV-2 antibodies among Belgian hospital healthcare workers (HCW) in April–December 2020.Design Prospective cohort study. Follow-up was originally planned until September and later extended.Setting Multicentre study, 17 hospitals.Participants 50 HCW were randomly selected per hospital. HCW employed beyond the end of the study and whose profession involved contact with patients were eligible. 850 HCW entered the study in April–May 2020, 673 HCW (79%) attended the September visit and 308 (36%) the December visit.Outcome measures A semiquantitative ELISA was used to detect IgG against SARS-CoV-2 in serum (Euroimmun) at 10 time points. In seropositive samples, neutralising antibodies were measured using a virus neutralisation test. Real-time reverse transcription PCR (RT-qPCR) was performed to detect SARS-CoV-2 on nasopharyngeal swabs. Participant characteristics and the presence of symptoms were collected via an online questionnaire.Results Among all participants, 80% were women, 60% nurses and 21% physicians. Median age was 40 years. The seroprevalence remained relatively stable from April (7.7% (95% CI: 4.8% to 12.1%) to September (8.2% (95% CI: 5.7% to 11.6%)) and increased thereafter, reaching 19.7% (95% CI: 12.0% to 30.6%) in December 2020. 76 of 778 initially seronegative participants seroconverted during the follow-up (incidence: 205/1000 person-years). Among all seropositive individuals, 118/148 (80%) had a positive neutralisation test, 83/147 (56%) presented or reported a positive RT-qPCR, and 130/147 (88%) reported COVID-19-compatible symptoms at least once. However, only 46/73 (63%) of the seroconverters presented COVID-19-compatible symptoms in the month prior to seroconversion.Conclusions The seroprevalence among hospital HCW was slightly higher than that of the general Belgian population but followed a similar evolution, suggesting that infection prevention and control measures were effective and should be strictly maintained. After two SARS-CoV-2 waves, 80% of HCW remained seronegative, justifying their prioritisation in the vaccination strategy.Trial registration number NCT04373889https://bmjopen.bmj.com/content/11/6/e050824.full
spellingShingle Bea Vuylsteke
Natalie Fischer
Kristien Verdonck
Isabelle Thomas
Els Duysburgh
Laure Mortgat
Veronik Hutse
Cyril Barbezange
Leo Heyndrickx
Ines Kabouche
Kevin K Ariën
Isabelle Desombere
Prevalence and incidence of anti-SARS-CoV-2 antibodies among healthcare workers in Belgian hospitals before vaccination: a prospective cohort study
BMJ Open
title Prevalence and incidence of anti-SARS-CoV-2 antibodies among healthcare workers in Belgian hospitals before vaccination: a prospective cohort study
title_full Prevalence and incidence of anti-SARS-CoV-2 antibodies among healthcare workers in Belgian hospitals before vaccination: a prospective cohort study
title_fullStr Prevalence and incidence of anti-SARS-CoV-2 antibodies among healthcare workers in Belgian hospitals before vaccination: a prospective cohort study
title_full_unstemmed Prevalence and incidence of anti-SARS-CoV-2 antibodies among healthcare workers in Belgian hospitals before vaccination: a prospective cohort study
title_short Prevalence and incidence of anti-SARS-CoV-2 antibodies among healthcare workers in Belgian hospitals before vaccination: a prospective cohort study
title_sort prevalence and incidence of anti sars cov 2 antibodies among healthcare workers in belgian hospitals before vaccination a prospective cohort study
url https://bmjopen.bmj.com/content/11/6/e050824.full
work_keys_str_mv AT beavuylsteke prevalenceandincidenceofantisarscov2antibodiesamonghealthcareworkersinbelgianhospitalsbeforevaccinationaprospectivecohortstudy
AT nataliefischer prevalenceandincidenceofantisarscov2antibodiesamonghealthcareworkersinbelgianhospitalsbeforevaccinationaprospectivecohortstudy
AT kristienverdonck prevalenceandincidenceofantisarscov2antibodiesamonghealthcareworkersinbelgianhospitalsbeforevaccinationaprospectivecohortstudy
AT isabellethomas prevalenceandincidenceofantisarscov2antibodiesamonghealthcareworkersinbelgianhospitalsbeforevaccinationaprospectivecohortstudy
AT elsduysburgh prevalenceandincidenceofantisarscov2antibodiesamonghealthcareworkersinbelgianhospitalsbeforevaccinationaprospectivecohortstudy
AT lauremortgat prevalenceandincidenceofantisarscov2antibodiesamonghealthcareworkersinbelgianhospitalsbeforevaccinationaprospectivecohortstudy
AT veronikhutse prevalenceandincidenceofantisarscov2antibodiesamonghealthcareworkersinbelgianhospitalsbeforevaccinationaprospectivecohortstudy
AT cyrilbarbezange prevalenceandincidenceofantisarscov2antibodiesamonghealthcareworkersinbelgianhospitalsbeforevaccinationaprospectivecohortstudy
AT leoheyndrickx prevalenceandincidenceofantisarscov2antibodiesamonghealthcareworkersinbelgianhospitalsbeforevaccinationaprospectivecohortstudy
AT ineskabouche prevalenceandincidenceofantisarscov2antibodiesamonghealthcareworkersinbelgianhospitalsbeforevaccinationaprospectivecohortstudy
AT kevinkarien prevalenceandincidenceofantisarscov2antibodiesamonghealthcareworkersinbelgianhospitalsbeforevaccinationaprospectivecohortstudy
AT isabelledesombere prevalenceandincidenceofantisarscov2antibodiesamonghealthcareworkersinbelgianhospitalsbeforevaccinationaprospectivecohortstudy