Investigation of viral load cycle threshold values in patients with SARS-CoV-2 associated pneumonia with real-time PCR method

Creative Commons License

Bakir A., Hosbul T., Cuce F., Artuk C., Taskın G., Caglayan M., ...More

Journal of Infection in Developing Countries, vol.15, no.10, pp.1408-1414, 2021 (Refereed Journals of Other Institutions) identifier identifier

  • Publication Type: Article / Article
  • Volume: 15 Issue: 10
  • Publication Date: 2021
  • Doi Number: 10.3855/jidc.14281
  • Title of Journal : Journal of Infection in Developing Countries
  • Page Numbers: pp.1408-1414
  • Keywords: Pneumonia, Real-time PCR, Rt-PCR, SARS-CoV-2, Viral load


Copyright © 2021 Bakir et al. This is an open-access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Introduction: In this study, we aimed investigate the relationship of SARS-CoV-2 viral load cycle threshold (Ct) values with pneumonia. Methodology: A total of 158 patients in whom SARS-CoV-2 was confirmed in upper respiratory tract (URT) samples with molecular method and who had computed tomography (CT) of the chest, between April 2020 and June 2020 were included in this retrospective cross-sectional study. Results: Mean age of 158 PCR positive patients was 45.22 ± 17.89 and 60.8% of them were male. Pneumonia was detected in 40.5% of the patients on their chest CT. A weak but significant correlation was found between SARS-CoV-2 Ct value detected with PCR in analysis of oropharyngeal/nasopharyngeal (OP/NP) samples and chest CT score (Pearson's r: 0.197, p = 0.01). No correlation was found between the first detected viral load Ct value and age, gender and mortality. There was no significant correlation between chest CT score and mortality. While the areas remaining under ROC curve for Ct value in analysis of OP/NP samples in prediction of chest CT score ≥ 1, ≥ 5 and ≥ 10 were 0.564, 0.640 and 0.703 respectively. Conclusions: We found that the amount of SARS-CoV-2 viral load (inverse relationship with Ct) detected in OP/NP samples of patients with COVID-19 pneumonia did not reflect the increasing severity of pulmonary lesions on chest CT. Although primary target of SARS-CoV-2 is all epithelial cells of the respiratory tract we believe studies comparing viral loads in lower respiratory tract samples are needed to determine the severity of pulmonary disease.