Trajectory and impact factors of cycle threshold values of virus load in respiratory tract in children infected with severe acute respiratory syndrome coronavirus 2 Omicron variants
10.3760/cma.j.cn311365-20220727-00321
- VernacularTitle:新型冠状病毒奥密克戎变异株感染患儿呼吸道病毒核酸载量的循环阈值变化及其影响因素
- Author:
Xiang CHEN
1
;
Jianguo ZHOU
;
Yanming LU
;
Yiwei CHEN
;
Ting ZHANG
;
Hui YU
;
Libo WANG
;
Wenhao ZHOU
Author Information
1. 复旦大学附属儿科医院新生儿科，上海 201102
- Keywords:
SARS-CoV-2;
Child;
Viral load;
Cycle threshold value
- From:
Chinese Journal of Infectious Diseases
2023;41(2):111-115
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the clinical characteristics of children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variants, and the impact factors of duration of cycle threshold (Ct) values turning to ≥35 detected by nucleotide test.Methods:Children aged 0 to 14 years with clinical symptoms of Omicron variants infection who admitted to designated hospital in Shanghai City (Renji Hospital, South Branch, Shanghai Jiao Tong University School of Medicine) from April 7 to June 2, 2022 were enrolled. The daily nasopharyngeal swab specimens were used for SARS-CoV-2 nucleic acid detecting by polymerase chain reaction and the results were expressed as Ct values. The T Ct≥ x was defined as from the symptom onset or first positive nucleic acid test results (the earlier data) to Ct≥ x of the open reading frame 1ab ( ORF1 ab) gene, which was the time duration from the initial to a specific Ct value.Clinical data were collected, including age, sex, vaccination and comorbidities.Cox model was performed to analyzed the impact factors of T Ct≥35. Results:A total of 871 pediatric cases with a median age of two years (ranging from one month to 14 years old) were included. Among them, 474 cases (54.4%) were male, and 89 cases (10.2%) had underlying diseases including congenital heart disease, solid tumors and epilepsy. There were 572(65.7%) mild cases, 298(34.2%) common cases, one (0.1%) severe case and no critical cases or deaths. The T Ct≥35 was 12(10, 14) days. Cox model indicated that compared to children aged one to 12 months, children aged 37 to 84 months and 85 to 168 months had shorter T Ct≥35 (hazard ratio ( HR)=1.55 and 1.84, respectively, both P<0.001). After adjusted with age, comparing to unvaccinated patients, patients with one or two shots vaccine had shorter T Ct≥35 (adjected hazard ratio (a HR)=1.49, P=0.011), and common patients had longer T Ct≥35 than mild patients (a HR=0.78, P=0.002), and patients with comorbidities had longer T Ct≥35than patients without comorbidities (a HR=0.38, P<0.001).The duration of T Ct≥28, T Ct≥30, T Ct≥33 and T Ct≥35 in children without underlying diseases were 7(6, 9) d, 9(7, 10) d, 10(8, 11) d and 12(10, 14) d, respectively. Conclusions:Age, vaccination, disease severity and underlying diseases could affect the duration of SARS-CoV-2 nucleotide turning to negative (Ct value≥35) in children infected with Omicron variants.
