SARS-CoV-2 Viral dynamics

Background: Cases of undiagnosed pneumonia have emerged, and sequencing of
respiratory samples indicated the presence of SARS-CoV-2 causing
COVID-19. Patients with higher viral load and lower Ct values
tend to have progressive disease and severe lung injury. The objective of
this study is to describe the clinical manifestation and disease outcomes
of COVID-19 patients in relation to their Ct values. Methods:
A retrospective, single-center observational study was performed,
including patients admitted to King Faisal Specialist Hospital and
Research Centre (KFSH&RC) Riyadh in one month in 2020 and have a
confirmed diagnosis of COVID-19. The Ct value was identified to determine
the viral load. All patients were treated according to KFSH&RC
guidelines. Patients were divided into HCQ/AZI and non HCQ/AZI
treated groups. Results: There were many days where
Ct values were not available. An attempt at imputing information
for missing Ct values was made using logic. The logic leads to an
ordinal Ct score 1, 2, 3, or 4. As a result, complete
Ct score profiles were available. There was no evidence of
statistically significant difference between the two groups in regard to
clinical severity, duration to negative test, or changes in Ct
values.  Conclusion: There is little knowledge known to the time
profile of Ct values and their relation to disease course of COVID-19.
This study provides insight on how Ct values might be used to determine
treatment efficacy. As it might be difficult to obtain Ct values at all
times, this study provides an imputation method that may be used with
conservative statistical assumptions for analyses of Ct
profiles.