Impact of SARS-CoV-2 viral load and duration of symptoms before hospital admission on the mortality of hospitalized COVID-19 patients

Purpose Assess the impact of viral load estimated by cycle threshold (Ct) of reverse transcription real time-polymerase chain reaction (rRT-PCR) and the days from symptoms onset on mortality in hospitalized patients with COVID19. Methods Retrospective observational study of 782 patients with a positive rRT-PCR from a nasopharyngeal swab was performed within the first 24 h from admission. Demographic data, clinical manifestations and laboratory parameters were collected. Uni- and multivariate analyses were performed to identify factors associated with mortality at 60 days. Results Ct was divided into three groups and the mortality rate decreased from 27.3 to 20.7% and 9.8% for Ct values of <= 20, 21-25 and > 25, respectively (P = 0.0001). The multivariate analysis identified as predictors of mortality, a Ct value < 20 (OR 3.13, CI 95% 1.38-7.10), between 21-25 (OR 2.47, CI 95% 1.32-4.64) with respect to a Ct value > 25. Days from symptoms onset is a variable associated with mortality as well (DSOA) <= 6 (OR 1.86, CI 95% 1.00-3.46), among other factors. Patients requiring hospital admission within 6 DSOA with a Ct value <= 25 had the highest mortality rate (28%). Conclusions The inclusion of Ct values and DSOA in the characterization of study populations could be a useful tool to evaluate the efficacy of antivirals.

Automated summary

By examining the relationship between viral load estimated by Ct and the days from symptoms onset on mortality in hospitalized COVID-19 patients, this study found that lower Ct values and a shorter time from symptoms onset were associated with higher mortality rates.