Home    中文  
 
  • Search
  • lucene Search
  • Citation
  • Fig/Tab
  • Adv Search
Just Accepted  |  Current Issue  |  Archive  |  Featured Articles  |  Most Read  |  Most Download  |  Most Cited

Chinese Journal of Experimental and Clinical Infectious Diseases(Electronic Edition) ›› 2025, Vol. 19 ›› Issue (06): 353-361. doi: 10.3877/cma.j.issn.1674-1358.2025.06.005

• Research Article • Previous Articles    

Influencing factors of nucleic acid conversion time to negtive and clinical characteristics of severe acute respiratory syndrome coronavirus 2 infection of children in different age groups during the Omicron variant pandemic

Kaihua Dong, Yanqing Yao(), Min Miao   

  1. Pediatrics, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
  • Received:2025-08-28 Online:2025-12-15 Published:2026-02-12
  • Contact: Yanqing Yao

Abstract:

Objective

To investigate the influencing factors for nucleic acid negative conversion and cinical characteristic of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) of children in different age groups during the Omicron epidemic.

Methods

The clinical data of 155 children infected with SARS-CoV-2 admitted to Beijing Ditan Hospital, Capital Medical University from January 28th, 2022 to June 20th, 2023 were analyzed, retrospectively. According to the differences in immune system development and epidemiological characteristics, children were divided into<7-year-old group (24 cases), 7-12-year-old group (36 cases) and>12-year-old group (95 cases). The clinical characteristics, laboratory test indicators and vaccination distribution of the three groups were compared, respectively; Inter-group comparisons were analyzed by Chi-square test, rank sum test or one-way ANOVA. The related factors for SARS-CoV-2 nucleic acid conversion to negative were screened by Spearman correlation analysis, and the independent influencing factors were identified by constructing multiple linear regression model.

Results

The proportion of children<7-year-old with a clinical classification of common type was higher than that of 7-12-year-old group (20.83% vs. 0.00%: P=0.008) and>12-year-old group (20.83% vs. 2.11%: P=0.004), with significant differences. The hospital duration [9.00 (8.00, 14.00) days] and nucleic acid negative conversion time [7.00 (6.25, 7.00) days] of children in<7-year-old group were shorter than those of 7-12-year-old group [14.00 (9.25, 15.75) days, 9.00 (6.00, 12.00) days] and>12-year-old group [13.00 (10.00, 15.00) days, 10.00 (8.00, 12.00) days], with significant differences (all P<0.05). The distribution of cronavirus dsease 2019 (COVID-19) vaccine doses in<7-year-old group [0 dose: 62.50% (15/24), 1 dose: 12.50% (3/24), 2 doses: 25.00% (6/24), 3 doses: 0.00% (0/24)] were different from those of 7-12-year-old group [0 dose: 5.56% (2/36), 1 dose: 11.11% (4/36), 2 doses: 77.78% (28/36), 3 doses: 5.56% (2/36)] and>12-year-old group [0 dose: 4.21% (4/95), 1 dose: 3.16% (3/95), 2 doses: 90.53% (86/95), 3 doses: 2.11% (2/95)], with significant differences (Z=-5.810, P<0.001; Z=-7.251, P<0.001). The incidence of nasal congestion and runny nose of children in<7-year-old group [39.13% (9/23)] was higher than that of>12-year-old group [14.12% (12/85)], with significant difference (P=0.015). The incidence of pharyngeal discomfort of children in>12-year-old group [57.65% (49/85)] was higher than that of<7-year-old group [21.74% (5/23)], with significant difference (χ2=9.336, P=0.002). The incidence of convulsions, vomiting and diarrhea among<7-year-old group, 7-12-year-old group and>12-year-old group were with significant differences (χ2=6.029, P=0.026; χ2=6.614, P=0.027), but no statistically significant difference was found between any two groups after Bonferroni correction (all P>0.0167). The proportion of children with elevated interleukin (IL) 6 in>12-year-old group [47.37% (45/95)] were lower than those of<7-year-old group [75.00% (18/24)] and 7-12-year-old group [72.22% (26/36)], with significant differences (χ2=5.872, P=0.015; χ2=6.496, P=0.011). The levels of lactate dehydrogenase [182.15 (161.00, 215.00) U/L], D-dimer [0.25 (0.18, 0.49) μg/ml] and N gene Ct value [21.92 (17.98, 26.41)] of children in>12-year-old group were all lower than those of<7-year-old group [275.35 (215.45, 320.10) U/L, 0.49 (0.33, 0.76) μg/ml, 27.59 (22.53, 32.60)] and 7-12-year-old group [237.35 (205.57, 260.15) U/L, 0.36 (0.25, 0.87) μg/ml, 27.90 (21.33, 34.44)], with significant differences (all P<0.05). The ORF1ab gene Ct value [23.80 (20.56, 29.30)] of children in>12-year-old group was lower than that of 7-12-year-old group [30.07 (22.85, 36.46)], with significant difference (Z=3.083, P=0.002). The anti-SARS-CoV-2 IgG level [3.32 (1.57, 8.28) S/CO] of children in 7-12-year-old group was higher than those of<7-year-old group [0.81 (0.03, 14.58) S/CO] and>12-year-old group [1.36 (0.58, 4.18) S/CO], with significant differences (Z=-2.537, P=0.034; Z=2.421, P=0.046). Spearman correlation analysis showed that age (ρ=0.312, P<0.001), body mass index (ρ=0.250, P=0.002), having received more than two doses of vaccine (ρ=0.326, P<0.001), presence of symptoms (ρ=0.445, P<0.001), fever (ρ=0.334, P<0.001), pharyngeal discomfort (ρ=0.401, P<0.001), headache and dizziness (ρ=0.252, P=0.002), neutrophil-to-lymphocyte ratio (ρ=0.369, P<0.001), IL-6 (ρ=0.192, P=0.016), and creatinine (ρ=0.323, P<0.001) were positively correlated with the time of SARS-CoV-2 nucleic acid negative conversion, while aspartate aminotransferase (ρ=-0.278, P<0.001), lactate dehydrogenase (ρ=-0.175, P=0.029), activated partial thromboplastin time (ρ=-0.162, P=0.044), D-dimer (ρ=-0.331, P<0.001) and anti-SARS-CoV-2 IgG (ρ=-0.278, P<0.001) were negatively correlated with the time of SARS-CoV-2 nucleic acid negative conversion, all with significant differences. The multiple linear regression model showed that the model was significant as a whole (F=7.016, P<0.001), and this model could explain 43.4% of the variation in SARS-CoV-2 nucleic acid negative conversion (R2=0.434). Whether having symptoms (β=0.263, 95%CI: 0.873-6.513, P=0.011) and pharyngeal discomfort (β=0.153, 95%CI: 0.029-2.603, P=0.045) were independent risk factors for delayed SARS-CoV-2 nucleic acid negative conversion, and the level of anti-SARS-CoV-2 IgG (β=-0.209, 95%CI: -0.022-0.002, P=0.022) was an independent protective factor for shortened SARS-CoV-2 nucleic acid negative conversion time.

Conclusions

During the Omicron epidemic, the clinical manifestations of children infected with SARS-CoV-2 were mainly mild, and the clinical features were closely related to age. Presence of symptoms and sore throat could prolong the time of SARS-CoV-2 nucleic acid negativity, while high level of SARS-CoV-2 IgG antibody could help shorten the conversion time to negativity. Individualized management of children in different age groups should be emphasized, and the value of vaccination and antibody monitoring in prognosis assessment should be highlighted.

Key words: Children, Severe acute respiratory syndrome coronavirus 2, Omicron variant strain, Clinical characteristics, Influencing factor

京ICP 备07035254号-20
Copyright © Chinese Journal of Experimental and Clinical Infectious Diseases(Electronic Edition), All Rights Reserved.
Tel: 010-85322058 E-mail: editordt@163.com
Powered by Beijing Magtech Co. Ltd