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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.


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  1. Corman VM, Landt O, Kaiser M, Molenkamp R, Meijer A, Chu DK, et al. Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR. Euro Surveill. 2020;25(3):2000045.  https://doi.org/10.2807/1560-7917.ES.2020.25.3.2000045  PMID: 31992387 
  2. Boddington NL, Charlett A, Elgohari S, Walker JL, Mcdonald H, Byers C, et al. COVID-19 in Great Britain: epidemiological and clinical characteristics of the first few hundred (FF100) cases: a descriptive case series and case control analysis. medRxiv. 2020.05.18.20086157. Available from: http://medrxiv.org/content/early/2020/05/22/2020.05.18.20086157
  3. World Health Organization (WHO). Clinical management of COVID-19 (interim guidance). Geneva: WHO; 27 May 2020. Available from: https://www.who.int/publications-detail/clinical-management-of-covid-19
  4. Department of Health and Social Care. Statement from the UK Chief Medical Officers on extension of self-isolation period: 30 July 2020. London: Department of Health and Social Care; 30 July 2020. Available from: https://www.gov.uk/government/news/statement-from-the-uk-chief-medical-officers-on-extension-of-self-isolation-period-30-july-2020
  5. Wölfel R, Corman VM, Guggemos W, Seilmaier M, Zange S, Müller MA, et al. Virological assessment of hospitalized patients with COVID-2019. Nature. 2020;581(7809):465-9.  https://doi.org/10.1038/s41586-020-2196-x  PMID: 32235945 
  6. Kujawski SA, Wong KK, Collins JP, Epstein L, Killerby ME, Midgley CM, et al. First 12 patients with coronavirus disease 2019 (COVID-19) in the United States. medRxiv. 2020.03.09.20032896. Available from: http://medrxiv.org/content/early/2020/03/12/2020.03.09.20032896
  7. Bullard J, Dust K, Funk D, Strong JE, Alexander D, Garnett L, et al. Predicting infectious SARS-CoV-2 from diagnostic samples. Clin Infect Dis. 2020;ciaa638.  https://doi.org/10.1093/cid/ciaa638  PMID: 32442256 
  8. Arons MM, Hatfield KM, Reddy SC, Kimball A, James A, Jacobs JR, et al. , Public Health–Seattle and King County and CDC COVID-19 Investigation Team. Presymptomatic SARS-CoV-2 infections and transmission in a skilled nursing facility. N Engl J Med. 2020;382(22):2081-90.  https://doi.org/10.1056/NEJMoa2008457  PMID: 32329971 
  9. Perera RAPM, Tso E, Tsang OTY, Tsang DNC, Fung K, Leung YWY, et al. SARS-CoV-2 virus culture and subgenomic RNA for respiratory specimens from patients with mild coronavirus disease. Emerg Infect Dis. 2020;26(11).  https://doi.org/10.3201/eid2611.203219  PMID: 32749957 
  10. van Kampen JJA, van de Vijver DAMC, Fraaij PLA, Haagmans BL, Lamers MM, Okba N, et al. Shedding of infectious virus in hospitalized patients with coronavirus disease-2019 (COVID-19): duration and key determinants. medRxiv. 2020.06.08.20125310. Available from: http://medrxiv.org/content/early/2020/06/09/2020.06.08.20125310
  11. La Scola B, Le Bideau M, Andreani J, Hoang VT, Grimaldier C, Colson P, et al. Viral RNA load as determined by cell culture as a management tool for discharge of SARS-CoV-2 patients from infectious disease wards. Eur J Clin Microbiol Infect Dis. 2020;39(6):1059-61.  https://doi.org/10.1007/s10096-020-03913-9  PMID: 32342252 

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