tetano
Editor, Senior Moderator
J Med Virol
. 2021 Jul 15.
doi: 10.1002/jmv.27206. Online ahead of print.
Cycle threshold values in RT-PCR to determine dynamics of SARS-CoV-2 viral load: An approach to reduce isolation period for COVID-19 patients
Clara Aranha[SUP] 1 [/SUP], Vainav Patel[SUP] 2 [/SUP], Vikrant Bhor[SUP] 1 [/SUP], Dimpu Gogoi[SUP] 2 [/SUP]
Affiliations
Abstract
Severe acute respiratory syndrome coronavirus (SARS-CoV-2) has affected all inhabited continents, and India is currently experiencing a devastating second wave of Coronavirus disease-2019 (COVID-19). Here, we examined the duration of clearance of SARS-CoV-2 in respiratory samples from 207 infected cases by Real-time reverse-transcription polymerase chain reaction (RT-PCR). A substantial proportion of COVID-19 positive cases with Ct values ≥31 (45.7%) were subsequently tested negative for SARS-CoV-2 RNA within 7 days of initial detection of the viral load. A total of 60% of all the Covid-19 patients, irrespective of their Ct values, cleared SARS-CoV-2 RNA within 14 days of the initial detection. Longitudinal assessment of RT-PCR test results in individuals requiring 15-30 days to clear SARS-CoV-2 RNA showed a significant reduction of the viral load in samples with high or intermediate viral loads (Ct values ≤25 and between 26-30 respectively) but the follow-up group with low viral RNA (Ct values ≥31) exhibited a stable viral load. Together, these results suggest that COVID-19 positive cases with Ct values ≥31 require reduced duration to clear SARS-CoV-2 and thus, shorter isolation period for this group might be considered in order to facilitate adequate space in the Covid Care Centres and reduce burden on healthcare infrastructure. This article is protected by copyright. All rights reserved.
Keywords: COVID 19; Cycle threshold value; RT-PCR; SARS-CoV-2; isolation.
. 2021 Jul 15.
doi: 10.1002/jmv.27206. Online ahead of print.
Cycle threshold values in RT-PCR to determine dynamics of SARS-CoV-2 viral load: An approach to reduce isolation period for COVID-19 patients
Clara Aranha[SUP] 1 [/SUP], Vainav Patel[SUP] 2 [/SUP], Vikrant Bhor[SUP] 1 [/SUP], Dimpu Gogoi[SUP] 2 [/SUP]
Affiliations
- PMID: 34264527
- DOI: 10.1002/jmv.27206
Abstract
Severe acute respiratory syndrome coronavirus (SARS-CoV-2) has affected all inhabited continents, and India is currently experiencing a devastating second wave of Coronavirus disease-2019 (COVID-19). Here, we examined the duration of clearance of SARS-CoV-2 in respiratory samples from 207 infected cases by Real-time reverse-transcription polymerase chain reaction (RT-PCR). A substantial proportion of COVID-19 positive cases with Ct values ≥31 (45.7%) were subsequently tested negative for SARS-CoV-2 RNA within 7 days of initial detection of the viral load. A total of 60% of all the Covid-19 patients, irrespective of their Ct values, cleared SARS-CoV-2 RNA within 14 days of the initial detection. Longitudinal assessment of RT-PCR test results in individuals requiring 15-30 days to clear SARS-CoV-2 RNA showed a significant reduction of the viral load in samples with high or intermediate viral loads (Ct values ≤25 and between 26-30 respectively) but the follow-up group with low viral RNA (Ct values ≥31) exhibited a stable viral load. Together, these results suggest that COVID-19 positive cases with Ct values ≥31 require reduced duration to clear SARS-CoV-2 and thus, shorter isolation period for this group might be considered in order to facilitate adequate space in the Covid Care Centres and reduce burden on healthcare infrastructure. This article is protected by copyright. All rights reserved.
Keywords: COVID 19; Cycle threshold value; RT-PCR; SARS-CoV-2; isolation.