Rapid, early and accurate SARS-CoV-2 detection using RT-qPCR in primary care: a prospective cohort study (REAP-1)

  • Objectives: We explore the importance of SARS-CoV-2 sentinel surveillance testing in primary care during a regional COVID-19 outbreak in Austria. Design: Prospective cohort study. Setting: A single sentinel practice serving 22 829 people in the ski-resort of Schladming-Dachstein. Participants: All 73 patients presenting with mild-to-moderate flu-like symptoms between 24 February and 03 April, 2020. Intervention: Nasopharyngeal sampling to detect SARS-CoV-2 using real-time reverse transcriptase-quantitative PCR (RT-qPCR). Outcome measures: We compared RT-qPCR at presentation with confirmed antibody status. We split the outbreak in two parts, by halving the period from the first to the last case, to characterise three cohorts of patients with confirmed infection: early acute (RT-qPCR reactive) in the first half; and late acute (reactive) and late convalescent (non-reactive) in the second half. For each cohort, we report the number of cases detected, the accuracy of RT-qPCR, the duration and variety of symptoms, and the number of viral clades present. Results: Twenty-two patients were diagnosed with COVID-19 (eight early acute, seven late acute and seven late convalescent), 44 patients tested SARS-CoV-2 negative and 7 were excluded. The sensitivity of RT-qPCR was 100% among all acute cases, dropping to 68.1% when including convalescent. Test specificity was 100%. Mean duration of symptoms for each group were 2 days (range 1–4) among early acute, 4.4 days (1–7) among late acute and 8 days (2–12) among late convalescent. Confirmed infection was associated with loss of taste. Acute infection was associated with loss of taste, nausea/vomiting, breathlessness, sore throat and myalgia; but not anosmia, fever or cough. Transmission clusters of three viral clades (G, GR and L) were identified. Conclusions: RT-qPCR testing in primary care can rapidly and accurately detect SARS-CoV-2 among people with flu-like illness in a heterogeneous viral outbreak. Targeted testing in primary care can support national sentinel surveillance of COVID-19.

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Author:Werner LeberORCiD, Oliver LammelORCiD, Monika Redlberger-FritzORCiDGND, Maria Elisabeth Mustafa-Korninger, Reingard Christina Glehr, Jeremy CampORCiD, Benedikt AgererORCiD, Alexander LercherORCiDGND, Alexandra Popa, Jakob-Wendelin GengerORCiD, Thomas Penz, Stephan Aberle, Christoph BockORCiDGND, Andreas BergthalerORCiDGND, Karin StiasnyORCiD, Eva-Maria Hochstrasser, Christian Hoellinger, Andrea Siebenhofer-KroitzschORCiDGND, Christopher E. M. GriffithsORCiDGND, Jasmina Panovska-GriffithsORCiD
Parent Title (English):BMJ open
Publisher:BMJ Publishing Group
Place of publication:London
Document Type:Article
Date of Publication (online):2021/08/02
Date of first Publication:2021/08/02
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2023/10/09
Issue:8, art. e045225
Article Number:e045225
Page Number:10
First Page:1
Last Page:10
Data availability statement
Data are available upon reasonable request. All data relevant to the study are included in the article. Raw data are stored on a secure computer at the Institute of General Practice and Evidence-based Health Services Research, University of Graz, Austria.
Prepublication history for this paper is available online. To view these files, please visit the journal online (http://dx doi.org/ 10. 1136/ bmjopen- 2020-045225).
We thank the Styrian Academy for General Practice (STAFAM) for carrying the publication costs.
This research was self-funded by each individual co-author. This project received funding from the Vienna Science and Technology Fund (WWTF) as part of the WWTF COVID-19 Rapid Response Funding 2020. Award/Grant number is not applicable.
Dewey Decimal Classification:6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit
Licence (German):License LogoCreative Commons - CC BY-NC - Namensnennung - Nicht kommerziell 4.0 International