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. 2022 Aug 29:2022:5460400.
doi: 10.1155/2022/5460400. eCollection 2022.

Viral RNA Load in Symptomatic and Asymptomatic COVID-19 Omicron Variant-Positive Patients

Qian Wu  1   2   3 , Lixia Shi  2   4 , Haomin Li  5 , Shuping Huang  4 , Hongwei Li  2 , Li Li  2 , Jin Han  4 , Qi Wu  1   3   6 , Zhengcun Pei  7
Affiliations

Viral RNA Load in Symptomatic and Asymptomatic COVID-19 Omicron Variant-Positive Patients

Qian Wu et al. Can Respir J. .

Abstract

Objectives: Viral load is important when evaluating viral transmission potential, involving the use of a polymerase chain reaction (PCR) cycle threshold (Ct) value. We aimed to analyze the PCR Ct values of respiratory tract samples taken from patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant strains to evaluate these strains' viral dynamics.

Methods: This study comprised 361 patients. The Ct values of SARS-CoV-2-related respiratory samples were compared between symptomatic and asymptomatic patients.

Results: The median (25th percentile and 75th percentile) nasopharynx and oropharynx SARS-CoV-2 Ct values were 30.5 (24.5-35.0) and 34.5 (30.0-37.0) in the symptomatic group, respectively, and 27.8 (23.4-34.5) and 33.5 (26.0-35.0) in the asymptomatic group, respectively, without significance. In the symptomatic group, subgroup analyses according to age showed the mean nasal Ct value for patients aged >18 years was 29.0 (23.5-34.5), which was significantly lower than that of patients aged 0-4 years and 5-13 years (36.0 (30.5-38.0) and 34.5 (31.0-39.0), respectively). The nasal Ct value for asymptomatic patients aged >18 years was 25.5 (20.9-28.4), which was significantly lower than of patients aged 5-13 years (34.5 (25.6-36.4)).

Conclusion: Our findings suggest that the viral loads of asymptomatic and symptomatic patients did not differ significantly. However, adults infected with SARS-CoV-2 had higher nasal viral loads that those of young children.

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Conflict of interest statement

The authors declare that there are no conflicts of interest regarding the publication of this paper.

Figures

Figure 1
Figure 1
Ct values of nasopharyngeal nucleic acid tests in symptomatic patients stratified by age.
Figure 2
Figure 2
Ct values of nasopharyngeal nucleic acid tests in asymptomatic patients stratified by age.
Figure 3
Figure 3
Ct values of oropharyngeal nucleic acid tests in symptomatic patients stratified by age.
Figure 4
Figure 4
Ct values of oropharyngeal nucleic acid tests in asymptomatic patients stratified by age.
See this image and copyright information in PMC

References

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Supplementary concepts