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. 2020 Aug;25(32):2001483.
doi: 10.2807/1560-7917.ES.2020.25.32.2001483.

Duration of infectiousness and correlation with RT-PCR cycle threshold values in cases of COVID-19, England, January to May 2020

Anika Singanayagam  1   2 , Monika Patel  1   2 , Andre Charlett  3 , Jamie Lopez Bernal  4 , Vanessa Saliba  4 , Joanna Ellis  1 , Shamez Ladhani  4 , Maria Zambon  1 , Robin Gopal  1
Affiliations

Duration of infectiousness and correlation with RT-PCR cycle threshold values in cases of COVID-19, England, January to May 2020

Anika Singanayagam et al. Euro Surveill. 2020 Aug.

Erratum in

  • Correction for Euro Surveill. 2020;25(32).
    Eurosurveillance editorial team. Eurosurveillance editorial team. Euro Surveill. 2021 Feb;26(7):210218c. doi: 10.2807/1560-7917.ES.2021.26.7.210218c. Euro Surveill. 2021. PMID: 33602383 Free PMC article. No abstract available.

Abstract

Severe acute respiratory syndrome coronavirus 2 viral load in the upper respiratory tract peaks around symptom onset and infectious virus persists for 10 days in mild-to-moderate coronavirus disease (n = 324 samples analysed). RT-PCR cycle threshold (Ct) values correlate strongly with cultivable virus. Probability of culturing virus declines to 8% in samples with Ct > 35 and to 6% 10 days after onset; it is similar in asymptomatic and symptomatic persons. Asymptomatic persons represent a source of transmissible virus.

Keywords: COVID-19; SARS-CoV-2; coronavirus; infectiousness; public health policy; respiratory virus.

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Conflict of interest statement

Conflict of interest: None declared.

Figures

Figure 1
Figure 1
Detection of SARS-CoV-2 by RT-PCR targeting the RdRp gene, England, January–April 2020 (n = 754)
Figure 2
Figure 2
Relationship between RT-PCR Ct value and culture positivity in mixed effects logistic regression analysis, SARS-CoV-2, England, January–May 2020 (n = 324)
Figure 3
Figure 3
Relationship between culture positivity and time between symptom onset and sample collection, SARS-CoV-2, England, January–May 2020 (n = 246)
See this image and copyright information in PMC

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