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Systematic Review

Viral Load Difference between Symptomatic and Asymptomatic COVID-19 Patients: Systematic Review and Meta-Analysis

1
Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
2
Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, 44121 Ferrara, Italy
*
Author to whom correspondence should be addressed.
Academic Editor: Nicola Petrosillo
Infect. Dis. Rep. 2021, 13(3), 645-653; https://doi.org/10.3390/idr13030061
Received: 7 June 2021 / Revised: 1 July 2021 / Accepted: 12 July 2021 / Published: 16 July 2021
(This article belongs to the Special Issue Feature Papers in Infectious Diseases)
We conducted a systematic review and meta-analysis to investigate the possible difference in the SARS-CoV-2 viral load between asymptomatic and symptomatic COVID-19 patients. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed in abstracting data and assessing validity. We searched MEDLINE, Scopus, Web of Science and Google Scholar for all investigations in the English language, reporting data on the threshold cycle (Ct) from real-time RT-PCR assays for the RNA-dependent RNA polymerase (RdRp), envelope (E) and nucleocapsid (N) SARS-CoV-2 genes in asymptomatic and symptomatic COVID-19 patients. Results: Overall, 703 COVID-19 patients (553 symptomatic and 150 asymptomatic) were analyzed. Five investigations reported the mean age of patients, evidencing that asymptomatic patients were younger than symptomatic patients (34.0 vs. 40.3 years, respectively). Pooled data regarding the levels of expression of the RdRp gene revealed no significant difference between symptomatic and asymptomatic subjects. Similarly, no differences were observed comparing the mean Ct values for the E and N genes. Based on real-time RT-PCR data, no differences exist in the viral load between symptomatic and asymptomatic COVID-19 subjects considering Ct values for RdRp, E and N genes’ expression. Asymptomatic subjects may represent a reservoir of the infection and significantly contribute to the maintenance of the pandemic. View Full-Text
Keywords: COVID-19; viral load; real-time RT-PCR; SARS-CoV-2 COVID-19; viral load; real-time RT-PCR; SARS-CoV-2
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MDPI and ACS Style

Zuin, M.; Gentili, V.; Cervellati, C.; Rizzo, R.; Zuliani, G. Viral Load Difference between Symptomatic and Asymptomatic COVID-19 Patients: Systematic Review and Meta-Analysis. Infect. Dis. Rep. 2021, 13, 645-653. https://doi.org/10.3390/idr13030061

AMA Style

Zuin M, Gentili V, Cervellati C, Rizzo R, Zuliani G. Viral Load Difference between Symptomatic and Asymptomatic COVID-19 Patients: Systematic Review and Meta-Analysis. Infectious Disease Reports. 2021; 13(3):645-653. https://doi.org/10.3390/idr13030061

Chicago/Turabian Style

Zuin, Marco, Valentina Gentili, Carlo Cervellati, Roberta Rizzo, and Giovanni Zuliani. 2021. "Viral Load Difference between Symptomatic and Asymptomatic COVID-19 Patients: Systematic Review and Meta-Analysis" Infectious Disease Reports 13, no. 3: 645-653. https://doi.org/10.3390/idr13030061

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