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. 2021 Oct;83(4):458-466.
doi: 10.1016/j.jinf.2021.08.003. Epub 2021 Aug 5.

SARS-CoV-2 viral load at presentation to hospital is independently associated with the risk of death

Alex R Tanner  1 , Hang Phan  2 , Nathan J Brendish  3 , Florina Borca  2 , Kate R Beard  3 , Stephen Poole  3 , Tristan W Clark  4
Affiliations

SARS-CoV-2 viral load at presentation to hospital is independently associated with the risk of death

Alex R Tanner et al. J Infect. 2021 Oct.

Abstract

Objectives Previous studies have suggested that SARS-CoV-2 viral load, measured on upper respiratory tract samples at presentation to hospital using PCR Cycle threshold (Ct) value, has prognostic utility. However, these studies have not comprehensively adjusted for factors known to be intimately related to viral load. We aimed to evaluate the association between Ct value at admission and patient outcome whilst adjusting carefully for covariates. Methods We evaluated the association between Ct value at presentation and the outcomes of ICU admission and death, in patients hospitalised during the first wave of the pandemic in Southampton, UK. We adjusted for covariates including age, duration of illness and antibody sero-status, measured by neutralisation assay. Results 185 patients were analysed, with a median [IQR] Ct value of 27.9 [22.6-32.1]. On univariate analysis the Ct value at presentation was associated with the risk of both ICU admission and death. In addition, Ct value significantly differed according to age, the duration of illness at presentation and antibody sero-status. On multivariate analysis, Ct value was independently associated with risk of death (aOR 0.84, 95% CI 0.72-0.96; p = 0.011) but not ICU admission (aOR 1.04, 95% CI 0.93-1.16; p = 0.507). Neutralising antibody status at presentation was not associated with mortality or ICU admission (aOR 10.62, 95% CI 0.47-889; p = 0.199 and aOR 0.46, 95% CI 0.10-2.00; p = 0.302, respectively). Conclusions SARS-CoV-2 Ct value on admission to hospital was independently associated with mortality, when comprehensively adjusting for other factors and could be used for risk stratification.

Keywords: Antibodies; COVID-19; Prognosis; SARS-CoV-2; Viral load.

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Conflict of interest statement

Declaration of Competing Interest TWC has received speaker fees, honoraria, travel reimbursement, and equipment and consumables free of charge for the purposes of research outside of this submitted study, from BioFire diagnostics LLC and BioMerieux. TWC has received consultancy fees from Synairgen research Ltd, Randox laboratories Ltd and Cidara therapeutics. He a member of an advisory board for Roche and a member of two independent data monitoring committees for trials sponsored by Roche. He has acted as the UK chief investigator for an IMP study sponsored by Janssen. KRB has received honoraria from Randox laboratories Ltd. All other authors have no competing interests to declare.

Figures

Fig 1
Fig. 1
Flow of participants through the study.
Fig 2
Fig. 2
a and b. Partial effects Kaplan-Meier graphs of age (a) and viral load (b) at admission and the probability of survival outcomes for all hospitalised patients (n = 185).
See this image and copyright information in PMC

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