Relevant SARS‐CoV‐2 viremia is associated with COVID‐19 severity: Prospective cohort study and validation cohort

Early kinetics of SARS‐CoV‐2 viral load (VL) in plasma determined by quantitative reverse‐transcription polymerase chain reaction (RT‐PCR) was evaluated as a predictor of poor clinical outcome in a prospective study and assessed in a retrospective validation cohort. Prospective observational single‐center study including consecutive adult patients hospitalized with COVID‐19 between November 2020 and January 2021. Serial plasma samples were obtained until discharge. Quantitative RT‐PCR was performed to assess SARS‐CoV‐2 VL. The main outcomes were in‐hospital mortality, admission to the Intensive Care Unit (ICU), and their combination (Poor Outcome). Relevant viremia (RV), established in the prospective study, was assessed in a retrospective cohort including hospitalized COVID‐19 patients from April 2021 to May 2022, in which plasma samples were collected according to clinical criteria. Prospective cohort: 57 patients were included. RV was defined as at least a twofold increase in VL within ≤2 days or a VL > 300 copies/ml, in the first week. Patients with RV (N = 14; 24.6%) were more likely to die than those without RV (35.7% vs. 0%), needed ICU admission (57% vs. 0%) or had Poor Outcome (71.4% vs. 0%), (p < 0.001 for the three variables). Retrospective cohort: 326 patients were included, 18.7% presented RV. Patients with RV compared with patients without RV had higher rates of ICU‐admission (odds ratio [OR]: 5.6 [95% confidence interval [CI]: 2.1–15.1); p = 0.001), mortality (OR: 13.5 [95% CI: 6.3–28.7]; p < 0.0001) and Poor Outcome (OR: 11.2 [95% CI: 5.8–22]; p < 0.0001). Relevant SARS‐CoV‐2 viremia in the first week of hospitalization was associated with higher in‐hospital mortality, ICU admission, and Poor Outcome. Findings observed in the prospective cohort were confirmed in a larger validation cohort.