Evaluation of the relationship between progression and SARS-CoV-2 viral load in COVID-19 cases in Ankara, Turkey.

INTRODUCTION: Patients infected with SARS-CoV-2 may present with varying clinical pictures. This study aimed to examine the relationship between viral load cycle threshold value, clinical prognosis and other laboratory parameters in initial swab samples on the day of hospitalization. METHODOLOGY: This retrospective and cross-sectional study included 112 patients, who were diagnosed with SARS-CoV-2 via the Bio-Rad CFX96 TouchTM system. Cycle threshold values for the RdRp gene obtained from reverse transcriptase polymerase chain reaction positive patients were recorded. RESULTS: The mean age of the 112 patients was 47.57 ± 17 years. No relationship was found in symptoms, pneumonia, oxygen need, follow-up in intensive care unit, and mortality between patient groups with cycle threshold values of < 30 and ≥ 30. Frequencies of thrombocytopenia (50%) and elevated LDH levels were higher in patients with cycle threshold values of ≥ 30 (p = 0.02 and p = 0.04, respectively). There was a weak but significant correlation between cycle threshold values and CRP levels (Pearson's r = 0.207, p = 0.029). CONCLUSIONS: Symptoms or clinical prognosis were not significantly related to the SARS-CoV-2 viral load levels tested at admission or for the first time within the scope of this study. Thrombocytopenia and elevated LDH rates were higher in patients with cycle threshold values of ≥ 30. A weak but significant correlation was found between the viral load and CRP levels. Large-scale studies are needed to further elucidate this subject matter.

Investigation of Viral Load Cycle Threshold Values in Patients with SARS-CoV-2 Associated Pneumonia with Real-Time PCR Method.

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.