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. 2021 Nov 2;73(9):e2853-e2860.
doi: 10.1093/cid/ciaa1471.

Severe Acute Respiratory Syndrome Coronavirus 2 Seroprevalence Survey Among 17 971 Healthcare and Administrative Personnel at Hospitals, Prehospital Services, and Specialist Practitioners in the Central Denmark Region

Sanne Jespersen  1 , Susan Mikkelsen  2 , Thomas Greve  3 , Kathrine Agergård Kaspersen  2   4 , Martin Tolstrup  1 , Jens Kjærgaard Boldsen  2   4 , Jacob Dvinge Redder  5 , Kent Nielsen  6 , Anders Mønsted Abildgaard  7 , Henrik Albert Kolstad  8 , Lars Østergaard  1 , Marianne Kragh Thomsen  3 , Holger Jon Møller  7 , Christian Erikstrup  2   9
Affiliations

Severe Acute Respiratory Syndrome Coronavirus 2 Seroprevalence Survey Among 17 971 Healthcare and Administrative Personnel at Hospitals, Prehospital Services, and Specialist Practitioners in the Central Denmark Region

Sanne Jespersen et al. Clin Infect Dis. .

Abstract

Background: The objective of this study was to perform a seroprevalence survey on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among Danish healthcare workers to identify high-risk groups.

Methods: All healthcare workers and administrative personnel at the 7 hospitals, prehospital services, and specialist practitioner clinics in the Central Denmark Region were invited to be tested by a commercial SARS-CoV-2 total antibody enzyme-linked immunosorbent assay (Wantai Biological Pharmacy Enterprise Co, Ltd, Beijing, China).

Results: A total of 25 950 participants were invited. Of these, 17 971 had samples available for SARS-CoV-2 antibody testing. After adjustment for assay sensitivity and specificity, the overall seroprevalence was 3.4% (95% confidence interval [CI], 2.5%-3.8%). The seroprevalence was higher in the western part of the region than in the eastern part (11.9% vs 1.2%; difference: 10.7 percentage points [95% CI, 9.5-12.2]). In the high-prevalence area, the emergency departments had the highest seroprevalence (29.7%), whereas departments without patients or with limited patient contact had the lowest seroprevalence (2.2%). Among the total 668 seropositive participants, 433 (64.8%) had previously been tested for SARS-CoV-2 RNA, and 50.0% had a positive reverse-transcription polymerase chain reaction (PCR) result.

Conclusions: We found large differences in the prevalence of SARS-CoV-2 antibodies in staff working in the healthcare sector within a small geographical area of Denmark. Half of all seropositive staff had been tested positive by PCR prior to this survey. This study raises awareness of precautions that should be taken to avoid in-hospital transmission. Regular testing of healthcare workers for SARS-CoV-2 should be considered to identify areas with increased transmission.

Keywords: COVID-19; SARS-CoV-2; antibody; healthcare workers; serology.

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Figures

Figure 1.
Figure 1.
Epidemic timeline. Abbreviations: COVID-19, coronavirus disease 2019; PCR, polymerase chain reaction; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.
Figure 2.
Figure 2.
Distribution of adjusted seroprevalence according to geographical area in the Central Denmark Region. The Central Denmark Region covers an area of 13 000 km2. Herning and Holstebro Regional Hospitals serve the western part; Viborg and Silkeborg Regional Hospitals serve the central part; Randers and Horsens Regional Hospitals and Aarhus University Hospital serve the eastern part.
See this image and copyright information in PMC

References

    1. Sandri MT, Azzolini E, Torri V, et al. IgG serology in health care and administrative staff populations from 7 hospital representative of different exposures to SARS-CoV-2 in Lombardy, Italy. medRxiv [Preprint]. Posted online 26 May 2020. doi:10.1101/2020.05.24.20111245. - DOI
    1. Mansour M, Leven E, Muellers K, Stone K, Mendu DR, Wajnberg A. Prevalence of SARS-CoV-2 antibodies among healthcare workers at a tertiary academic hospital in New York City. J Gen Intern Med 2020; 35:2485–6. - PMC - PubMed
    1. Zhou F, Yu T, Du R, et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet 2020; 395:1054–62. - PMC - PubMed
    1. Comar M, Brumat M, Concas MP, et al. COVID-19 experience: first Italian survey on healthcare staff members from a mother-child research hospital using combined molecular and rapid immunoassays test. medRxiv [Preprint]. Posted online 22 April 2020. doi:10.1101/2020.04.19.20071563. - DOI
    1. Self WH, Tenforde MW, Stubblefield WB, et al. CDC COVID-19 Response Team; IVY Network Seroprevalence of SARS-CoV-2 among frontline health care personnel in a multistate hospital network—13 academic medical centers, April–June 2020. MMWR Morb Mortal Wkly Rep 2020; 69:1221–6. - PMC - PubMed

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