Duration of infectiousness and correlation with RT-PCR cycle threshold values in cases of COVID-19, England, January to May 2020
Anika Singanayagam, Monika Patel, André Charlett, Jamie Lopez Bernal, Vanessa Saliba, Joanna Ellis, Shamez Ladhani, Maria Zambon, Robin Gopal
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.
Topics & Concepts
AsymptomaticCoronavirus disease 2019 (COVID-19)VirusCoronavirusSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2)VirologyMedicineRespiratory tractRespiratory systemViral load2019-20 coronavirus outbreakCorrelationInternal medicineInfectious disease (medical specialty)DiseaseMathematicsOutbreakGeometrySARS-CoV-2 detection and testingSARS-CoV-2 and COVID-19 ResearchCOVID-19 Clinical Research Studies