Skip to main content
Erschienen in: Critical Care 1/2020

Open Access 01.12.2020 | COVID-19 | Research Letter

Nasopharyngeal viral load predicts hypoxemia and disease outcome in admitted COVID-19 patients

verfasst von: Amir Shlomai, Haim Ben-Zvi, Ahinoam Glusman Bendersky, Noa Shafran, Elad Goldberg, Ella H. Sklan

Erschienen in: Critical Care | Ausgabe 1/2020

Hinweise
Amir Shlomai and Haim Ben Zvi contributed equally to this work.
Elad Goldberg and Ella H. Sklan are senior authors and contributed equally to this article.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Abkürzungen
SARS-CoV-2
Severe acute respiratory syndrome coronavirus 2
COVID-19
Coronavirus disease 2019
IQR
Interquartile range
Ct
Cycle threshold
RT-PCR
Reverse transcription polymerase chain reaction
OR
Odds ratio
CI
Confidence interval
LDH
Lactate dehydrogenase
BOS
Blood oxygen saturation
CRP
C-reactive protein
ICU
Intensive care unit

Introduction

The SARS-CoV-2 pandemic imposes an unprecedented burden on hospitals treating coronavirus disease 2019 (COVID-19) patients. Thus, clinical parameters accurately predicting disease outcome are needed. Here, we identified a correlation between viral load measured around admission, lung inflammation, and disease outcome. Similarities and differences between related studies are discussed.

Methods

Viral loads of COVID-19 patients admitted to Rabin Medical Center between March 16 and July 23, 2020, were analyzed (n = 170, females 42%, age 62 (IQR 46–73), hospitalization length 7.5 days (IQR 3–13)). Clinical and demographic data were collected from the patients’ electronic medical records. Nasopharyngeal samples were collected and transferred to the microbiology laboratory for testing. Quantitative RT-PCR was performed using the Allplex™ 2019-nCoV Assay (Seegene). Presented are Ct values of the nucleocapsid N gene from the first test performed for each patient. Simple linear regression of clinical parameters against the viral load was fitted to the data to assess the association between viral and clinical parameters using GraphPad Prism. Adjusted odds ratio (OR) of mechanical ventilation and mortality were calculated for each significant variable with 95% confidence intervals (CI) using SPSS, version 26.

Results

Cycle threshold values of the first test performed for all admitted COVID-19 patients were correlated with the patients’ clinical parameters. Among the parameters tested (lowest values of albumin, lymphocyte count, blood oxygen saturation (BOS) and systolic blood pressure, peak levels of lactate dehydrogenase (LDH), C-reactive protein (CRP), ferritin, white blood cell count, and fever), only BOSmin (R = 0.07, p = 0.0004) showed significant correlation (Fig. 1). Interestingly, patients’ age was also significantly correlated with viral load (Fig. 1). Non-survivors and mechanically ventilated patients (n = 21) had a significantly higher viral load (8-folds, Ct = 23.43 ± 5.38) compared to surviving non-intubated patients (n = 149, Ct = 29 ± 5.55, t test p < 0.0001, Fig. 2). A multivariate analysis adjusted for age, gender, and BOSmin revealed that low viral load was independently associated with reduced risk for mechanical ventilation and mortality (OR = 0.90, 95% CI 0.81–0.99, p = 0.046). Furthermore, BOS and patients’ age were also independently associated with mechanical ventilation and death (OR = 0.91, 95% CI 0.84–0.98, p = 0.009 for BOS and OR = 1.05, 95% CI 1.004–1.097 for age).

Discussion

Our results show a direct link between nasopharyngeal viral load and hypoxemia, as well as worse disease outcomes in admitted patients with COVID-19. Previous studies tested the association between viral load and survival. In agreement with our results, a study of 678 admitted patients in New York found that 35.0% of patients with a high viral load on admission died, compared to 6.2% of patients with low viral loads [1]. In an older age cohort (n = 48, age 67–97) from Belgium, clinical frailty scale, LDH, and viral load predicted survival [2]. Intensive care unit (ICU) admission also positively correlated with detectable viral RNA in anal swabs [3]. In contrast, a Swiss study found no correlation between viral load and disease outcome. The study compared the viral load of patients admitted to the ICU (n = 48) to patients treated in a screening unit (n = 723) [4]. It is not clear, however, whether these patients were later admitted, intubated, or survived. A different New York study (n = 205) found no association between viral load and disease severity parameters. However, this study mainly compared non-hospitalized to hospitalized patients [5]. Several markers were associated with COVID-19 severity, the most accepted is IL-6 [6]. However, IL-6 is not routinely tested at admission and might reflect other inflammatory conditions. Thus, in spite of differences in test kits and procedures between different laboratories and institutions, viral load might provide a rapid screening tool for COVD-19 severity among admitted patients.

Acknowledgements

EHS acknowledges the Milner Foundation for its support.
This retrospective study was approved by the Rabin Medical Center Helsinki Committee (0252-20-RMC) and the Tel Aviv University Ethics Committee (0001269-3). The need for informed consent was waived due to its retrospective nature.
Not applicable.

Competing interests

Not applicable.
Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://​creativecommons.​org/​licenses/​by/​4.​0/​. The Creative Commons Public Domain Dedication waiver (http://​creativecommons.​org/​publicdomain/​zero/​1.​0/​) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Literatur
1.
Zurück zum Zitat Magleby R, Westblade LF, Trzebucki A, Simon MS, Rajan M, Park J, Goyal P, Safford MM, Satlin MJ. Impact of SARS-CoV-2 viral load on risk of intubation and mortality among hospitalized patients with coronavirus disease 2019. Clin Infect Dis. 2020;ciaa851, https://doi.org/10.1093/cid/ciaa851. Magleby R, Westblade LF, Trzebucki A, Simon MS, Rajan M, Park J, Goyal P, Safford MM, Satlin MJ. Impact of SARS-CoV-2 viral load on risk of intubation and mortality among hospitalized patients with coronavirus disease 2019. Clin Infect Dis. 2020;ciaa851, https://​doi.​org/​10.​1093/​cid/​ciaa851.
2.
Zurück zum Zitat De Smet R, Mellaerts B, Vandewinckele H, Lybeert P, Frans E, Ombelet S, Lemahieu W, Symons R, Ho E, Frans J, et al. Frailty and mortality in hospitalized older adults with COVID-19: retrospective observational study. J Am Med Dir Assoc. 2020;21(7):928–32 e921.CrossRef De Smet R, Mellaerts B, Vandewinckele H, Lybeert P, Frans E, Ombelet S, Lemahieu W, Symons R, Ho E, Frans J, et al. Frailty and mortality in hospitalized older adults with COVID-19: retrospective observational study. J Am Med Dir Assoc. 2020;21(7):928–32 e921.CrossRef
3.
Zurück zum Zitat Lin W, Xie Z, Li Y, Li L, Wen C, Cao Y, Chen X, Ou X, Hu F, Li F, et al. Association between detectable SARS-COV-2 RNA in anal swabs and disease severity in patients with coronavirus disease 2019. J Med Virol. 2020;1–9. Lin W, Xie Z, Li Y, Li L, Wen C, Cao Y, Chen X, Ou X, Hu F, Li F, et al. Association between detectable SARS-COV-2 RNA in anal swabs and disease severity in patients with coronavirus disease 2019. J Med Virol. 2020;1–9.
5.
Zurück zum Zitat Argyropoulos KV, Serrano A, Hu J, Black M, Feng X, Shen G, Call M, Kim MJ, Lytle A, Belovarac B, et al. Association of initial viral load in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients with outcome and symptoms. Am J Pathol. 2020;190(9):1881–1887. Argyropoulos KV, Serrano A, Hu J, Black M, Feng X, Shen G, Call M, Kim MJ, Lytle A, Belovarac B, et al. Association of initial viral load in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients with outcome and symptoms. Am J Pathol. 2020;190(9):1881–1887.
6.
Zurück zum Zitat Liu T, Zhang J, Yang Y, Ma H, Li Z, Zhang J, Cheng J, Zhang X, Zhao Y, Xia Z, et al. The role of interleukin-6 in monitoring severe case of coronavirus disease 2019. EMBO Mol Med. 2020;12(7):e12421.CrossRef Liu T, Zhang J, Yang Y, Ma H, Li Z, Zhang J, Cheng J, Zhang X, Zhao Y, Xia Z, et al. The role of interleukin-6 in monitoring severe case of coronavirus disease 2019. EMBO Mol Med. 2020;12(7):e12421.CrossRef
Metadaten
Titel
Nasopharyngeal viral load predicts hypoxemia and disease outcome in admitted COVID-19 patients
verfasst von
Amir Shlomai
Haim Ben-Zvi
Ahinoam Glusman Bendersky
Noa Shafran
Elad Goldberg
Ella H. Sklan
Publikationsdatum
01.12.2020
Verlag
BioMed Central
Erschienen in
Critical Care / Ausgabe 1/2020
Elektronische ISSN: 1364-8535
DOI
https://doi.org/10.1186/s13054-020-03244-3

Weitere Artikel der Ausgabe 1/2020

Critical Care 1/2020 Zur Ausgabe

Update AINS

Bestellen Sie unseren Fach-Newsletter und bleiben Sie gut informiert.