Is Higher Viral Load in SARS-CoV-2 Associated With Death?

Abstract

There is no proven prognostic marker or adequate number of studies in patients hospitalized for Coronavirus Disease-2019 (COVID-19). We conducted a retrospective cohort study of patients hospitalized with COVID-19 from March 14 to June 17, 2020, at Sao Paulo Hospital. SARS-CoV-2 viral load was assessed using the cycle threshold (Ct) values obtained from an RTPCR assay applied to the nasopharyngeal swab samples. Disease severity and patient outcomes were compared. Among the 875 patients, 50.1% (439/875) had mild, 30.4% (266/875) moderate, and 19.5% (170/875) severe disease. A Ct value of <25 (472/875) indicated a high viral load, which was independently associated with mortality (OR: 0,34; 95% CI: 0,217 to 0,533; p < 0.0001). Admission SARS-CoV-2 viral load is an important surrogate biomarker of infectivity and is independently associated with mortality among patients hospitalized with COVID-19.

The association of viral load and disease severity in children with COVID‐19

“…Our findings demonstrate that the ∆ C t which was assumed to be inversely related to viral load were similar in all clinical courses and in all age groups in children with COVID‐19 in contrast to some previous reports, in which they reported that C t values were associated with disease severity 9,17 and even mortality 20,21 . On the other hand, limited number of studies reported any difference in median Ct values of groups with different symptom statuses, such as asymptomatic, presymptomatic, atypical, and typical symptoms 15,22 .…”

Diagnostic SARS-CoV-2 Cycle Threshold Value Predicts Disease Severity, Survival, and Six-Month Sequelae in COVID-19 Symptomatic Patients

“…In contrast, studies where a positive association between nasopharyngeal SARS-CoV-2 Ct values and COVID-19 severity or outcomes was detailed are flourishing [ 6 , 7 , 9 , 10 , 11 , 12 , 17 , 34 , 35 ]. Most of them included samples of more than 100 individuals with the reference swab represented by the diagnostic one, despite only two reported the time between disease onset and swab collection [ 7 , 17 ].…”

“…Further to the recognized risk factors for severity, the initial prognostic workup of persons infected by SARS-CoV-2 would also benefit from viral biomarkers able to predict COVID-19 evolution. In this regard, it is a current matter of debate whether SARS-CoV-2 viral load is an impactful factor in determining disease outcomes [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. Previous evidence from SARS-CoV and influenza suggests that the higher the initial viral load, the worse the clinical evolution [ 18 , 19 ].…”

“…Previous evidence from SARS-CoV and influenza suggests that the higher the initial viral load, the worse the clinical evolution [ 18 , 19 ]. To date, few studies have investigated the relationships among SARS-CoV-2 viral load (usually measured by the proxy PCR cycle threshold value, Ct), and mortality, disease progression, and overall severity [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 17 ]. Current data point towards a plausible positive correlation between the amount of detected virus and the degree of SARS-CoV-2 pneumonia severity, hypoxemia intensity, risk of death, as well as of hematological, biochemical, and inflammatory alterations [ 6 , 9 , 10 , 11 , 12 , 17 , 20 , 21 ].…”

Early postmortem mapping of SARS-CoV-2 RNA in patients with COVID-19 and the correlation with tissue damage

“…The authors suggest using the Ct-value to identify patients with a high risk for severe clinical courses. Further studies also indicate that the viral load may serve as a surrogate marker of infectivity associated with mortality rates ( Faico-Filho et al, 2020 ).…”