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. 2021 Jun 23:149:e150.
doi: 10.1017/S0950268821001345.

Detection and viral RNA shedding of SARS-CoV-2 in respiratory specimens relative to symptom onset among COVID-19 patients in Bavaria, Germany

Tom Woudenberg  1   2 , Ute Eberle  3 , Durdica Marosevic  1 , Bernhard Liebl  4   5 , Nikolaus Ackermann  3 , Katharina Katz  1 , Andreas Sing  6 ; Bavarian SARS-CoV-2-Group
Collaborators, Affiliations

Detection and viral RNA shedding of SARS-CoV-2 in respiratory specimens relative to symptom onset among COVID-19 patients in Bavaria, Germany

Tom Woudenberg et al. Epidemiol Infect. .

Erratum in

Abstract

We assessed severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) reverse transcriptase-polymerase chain reaction (RT-PCR) diagnostic sensitivity and cycle threshold (Ct) values relative to symptom onset in symptomatic coronavirus disease-2019 (COVID-19) patients from Bavaria, Germany, of whom a subset was repeatedly tested. Locally weighted scatterplot smoothing method was used to assess the relationship between symptom onset and Ct-values. Kaplan-Meier plots were used to visualise the empirical probability of detecting viral ribonucleic acid (RNA) over time and estimate the time until clearance of viral RNA among the repeatedly tested patients. Among 721 reported COVID-19 cases, the viral RNA was detected in specimens taken between three days before and up to 48 days after symptom onset. The mean Ct-value was 28.6 (95% confidence interval (CI) 28.2-29.0) with the lowest mean Ct-value (26.2) observed two days after symptom onset. Up to 7 days after symptom onset, the diagnostic sensitivity of the RT-PCR among repeatedly sampled patients (n = 208) remained above 90% and decreased to 50% at day 12 (95% CI 10.5-21.5). Our data provide valuable estimates to optimise the timing of sampling of individuals for SARS-CoV-2 detection. A considerable proportion of specimens sampled before symptom onset had Ct-values comparable with Ct-values after symptom onset, suggesting the probability of presymptomatic transmission.

Keywords: COVID-19; RT-PCR; SARS-CoV-2; sensitivity; viral load.

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Figures

Fig. 1.
Fig. 1.
Distribution of day of sampling relative to symptom onset for 725 COVID-19 cases in Bavaria, Germany.
Fig. 2.
Fig. 2.
Ct values (to the E-gene target) of positive specimens shown by days since illness onset (n = 711). The smoothed line was fitted using the LOWESS method. Grey area is the 95% confidence interval.
Fig. 3.
Fig. 3.
Time until the loss of SARS-CoV-2 RNA detection after symptom onset among 208 patients tested at least twice in Bavaria, Germany. The red line and red-shaded area depict the empirical distribution of persistence of positive tests and 95% confidence interval, respectively.
Fig. 4.
Fig. 4.
Time until the loss of SARS-CoV-2 RNA detection after symptom onset among 208 patients tested at least twice in Bavaria, Germany stratified by (a) sex, (b) age and (c) reported fever.
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References

    1. Zhu N et al. (2020) A novel coronavirus from patients with pneumonia in China, 2019. New England Journal of Medicine 382, 727–733. - PMC - PubMed
    1. World Health Organisation. COVID-19 Weekly Epidemiological Update: WHO; 9 March 2021 (Weekly epidemiological update – 9 March 2021).
    1. Richardson S et al. (2020) Presenting characteristics, comorbidities, and outcomes among 5700 patients hospitalized with COVID-19 in the New York City area. JAMA 323, 2052–2059. - PMC - PubMed
    1. Russell TW et al. (2020) Estimating the infection and case fatality ratio for coronavirus disease (COVID-19) using age-adjusted data from the outbreak on the Diamond Princess cruise ship, February 2020. Eurosurveillance 25, 2000256. - PMC - PubMed
    1. Streeck H et al. (2020) Infection fatality rate of SARS-CoV2 in a super-spreading event in Germany. Nature Communications 11, 5829. - PMC - PubMed

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