COVID-19: Investigation of Transmission and Immunisation Among Hospital Staff

During the COVID-19 pandemic several countries have seen a high risk of transmission for health care personnel, with some countries having as many 20-25% of nurses and doctors either infected or showing symptoms of COVID-19.

In this prospective cohort study, we will systematically screen all hospital staff in the Capital Region of Denmark for IgM and IgG antibodies against SARS-CoV-2 using a point of care tests and an Elisa kit.

Testing will be offered 3 times: In April 2020, Maj 2020 and September 2020. All participants will submit a questionnaire regarding exposures, risk factors and symptoms of COVID-19 in relation to each testing. Follow-up will be through electronic patient records and national registries.

We will compare the group of health care personnel with data from a control group of healthy volunteer blood donors from the Danish Blood Donor Study.

The aim of the study is to investigate the proportion of hospital staff with SARS-CoV-2 antibodies during the study period compared to a control group representing the Danish population. We will compare the test characteristics of the two methods of testing, a point of care test and Elisa.

Further, we will investigate the extent to which prior immunization or infection is protective for future infection with COVID-19.

Study Overview

• Status: Completed
• Conditions: COVID
• Intervention / Treatment: Diagnostic test: IgM and IgG diagnostic kits to SARS-CoV-2; Diagnostic test: Elisa-test for IgM and IgG to SARS-CoV-2

• Study Type: Observational
• Enrollment (Actual): 44698

Contacts and Locations

Study Locations

• Denmark
  • Ballerup, Denmark, 2750
    • Psykiatrisk Center Ballerup
  • Copenhagen, Denmark, 2100
    • Rigshospitalet
  • Copenhagen, Denmark, 2100
    • Psykiatrisk Center København
  • Copenhagen, Denmark, 2300
    • Psykiatrisk Center Amager
  • Gentofte, Denmark, 2820
    • Psykiatrisk Center Stolpegaard
  • Glostrup, Denmark, 2600
    • Børne- og Ungdomspsykiatrisk Center
  • Glostrup, Denmark, 2700
    • Psykiatrisk Center Glostrup
  • Hillerød, Denmark, 3400
    • Nordsjaellands Hospital
  • Hillerød, Denmark, 3400
    • Psykiatrisk Center Nordsjælland
  • Roskilde, Denmark, 4000
    • Psykiatrisk Center Sankt Hans
  • Rønne, Denmark, 3700
    • Bornholms Hospital
  • Rønne, Denmark, 3700
    • Psykiatrisk Center Bornholm
  • Region Hovedstaden
    • Herlev, Region Hovedstaden, Denmark, 2730
      • Herlev Hospital
    • København NV, Region Hovedstaden, Denmark, 2400
      • Bispebjerg Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: N/A
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

All staff with any form of contact with patients, employed at any hospital in the Capital Region of Denmark will be offered to participate at their place of employment.

Description

Inclusion Criteria:

• >18 years old
• Consent to participation
• Employed at a Hospital in the Capitial Region of Denmark

Exclusion Criteria:

• None

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Hospital Staff in the Capital Region of Denmark	Diagnostic test: IgM and IgG diagnostic kits to SARS-CoV-2; Diagnostic kits for IgM/IgG antibodies to SARS-CoV-2; Diagnostic test: Elisa-test for IgM and IgG to SARS-CoV-2; Elisa-test for IgM and IgG to SARS-CoV-2
Healthy volunteer blood donors	Diagnostic test: IgM and IgG diagnostic kits to SARS-CoV-2; Diagnostic kits for IgM/IgG antibodies to SARS-CoV-2; Diagnostic test: Elisa-test for IgM and IgG to SARS-CoV-2; Elisa-test for IgM and IgG to SARS-CoV-2

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Positive IgM/IgG tests	Proportion of hospital staff who have a positive IgM/IgG tests for antibodies to SARS-CoV-2 on point of care test and/or Elisa compared to the background population	At inclusion
Positive IgM/IgG tests	Proportion of hospital staff who have a positive IgM/IgG tests for antibodies to SARS-CoV-2 on point of care test and/or Elisa compared to the background population	1 month
Positive IgM/IgG tests	Proportion of hospital staff who have a positive IgM/IgG tests for antibodies to SARS-CoV-2 on point of care test and/or Elisa compared to the background population	5 month
Comparison of the point of care test and Elisa	Comparison of the resultat from the point of care test and with results from Elisa	At inclusion
Comparison of the point of care test and Elisa	Comparison of the resultat from the point of care test and with results from Elisa	1 months
Comparison of the point of care test and Elisa	Comparison of the resultat from the point of care test and with results from Elisa	5 months
Re-infection rate	Number of patients, who were tested positive for antibodies on an earlier test and later are infected with COVID-19	180 days
Re-infection rate	Number of patients, who were tested positive for antibodies on an earlier test and later are infected with COVID-19	360 days
IgM/IgG positive participants on follow-up test	Proportion of IgM/IgG positive participants with a lasting immune response. This will be the participants who are still positive on follow-up	1 month
IgM/IgG positive participants on follow-up test	Proportion of IgM/IgG positive participants with a lasting immune response. This will be the participants who are still positive on follow-up	5 months

Collaborators and Investigators

• Sponsor: Herlev Hospital
• Collaborators: Rigshospitalet, Denmark; Hvidovre University Hospital; University Hospital Bispebjerg and Frederiksberg; Mental Health Services in the Capital Region, Denmark; Nordsjaellands Hospital
• Investigators: Principal Investigator: Kasper Iversen, Prof., Herlev-Gentofte Hospital; Principal Investigator: Henning Bundgaard, Prof., Rigshospitalet, Denmark; Principal Investigator: Henrik Ullum, Prof., Rigshospitalet, Denmark; Principal Investigator: Thomas Benfield, Prof., Hvidovre University Hospital; Principal Investigator: Susanne Dam Poulsen, Prof., Rigshospitalet, Denmark; Principal Investigator: Jørgen Rungby, Prof., Bispebjerg Hospital; Principal Investigator: Fredrik Folke, Associate prof., Akutberedskabet; Principal Investigator: Thea Kølsen Fischer, Nordsjællands Hospital; Principal Investigator: Ove Andersen, Prof., Hvidovre University Hospital; Principal Investigator: Ida Hageman, Mental Health Services in the Capital Region, Denmark

Publications and helpful links

General Publications

• Iversen K, Kristensen JH, Hasselbalch RB, Pries-Heje M, Nielsen PB, Knudsen AD, Fogh K, Norsk JB, Andersen O, Fischer TK, Juul Jensen CA, Torp-Pedersen C, Rungby J, Ditlev SB, Hageman I, Mogelvang R, Gybel-Brask M, Dessau RB, Sorensen E, Harritshoj L, Folke F, Sten C, Engel Moller ME, Benfield T, Ullum H, Jorgensen CS, Erikstrup C, Ostrowski SR, Nielsen SD, Bundgaard H. Seroprevalence of SARS-CoV-2 antibodies and reduced risk of reinfection through 6 months: a Danish observational cohort study of 44 000 healthcare workers. Clin Microbiol Infect. 2022 May;28(5):710-717. doi: 10.1016/j.cmi.2021.09.005. Epub 2021 Sep 17.
• Iversen K, Bundgaard H, Hasselbalch RB, Kristensen JH, Nielsen PB, Pries-Heje M, Knudsen AD, Christensen CE, Fogh K, Norsk JB, Andersen O, Fischer TK, Jensen CAJ, Larsen M, Torp-Pedersen C, Rungby J, Ditlev SB, Hageman I, Mogelvang R, Hother CE, Gybel-Brask M, Sorensen E, Harritshoj L, Folke F, Sten C, Benfield T, Nielsen SD, Ullum H. Risk of COVID-19 in health-care workers in Denmark: an observational cohort study. Lancet Infect Dis. 2020 Dec;20(12):1401-1408. doi: 10.1016/S1473-3099(20)30589-2. Epub 2020 Aug 3. Erratum In: Lancet Infect Dis. 2020 Oct;20(10):e250.

Study record dates

Study Major Dates

• Study Start (Actual): April 15, 2020
• Primary Completion (Actual): October 7, 2020
• Study Completion (Actual): October 7, 2020

Study Registration Dates

• First Submitted: April 11, 2020
• First Submitted That Met QC Criteria: April 13, 2020
• First Posted (Actual): April 15, 2020

Study Record Updates

• Last Update Posted (Actual): August 25, 2022
• Last Update Submitted That Met QC Criteria: August 24, 2022
• Last Verified: August 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Immunologic Factors; Immunoglobulin G; Immunoglobulin M
• Other Study ID Numbers: RegHCOVIDScreening

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No