UCL Great Ormond Street Institute of Child Health, London, United Kingdom.
MRC Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom.
JAMA Pediatr. 2021 Feb 1;175(2):143-156. doi: 10.1001/jamapediatrics.2020.4573.
The degree to which children and adolescents are infected by and transmit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear. The role of children and adolescents in transmission of SARS-CoV-2 is dependent on susceptibility, symptoms, viral load, social contact patterns, and behavior.
To systematically review the susceptibility to and transmission of SARS-CoV-2 among children and adolescents compared with adults.
PubMed and medRxiv were searched from database inception to July 28, 2020, and a total of 13 926 studies were identified, with additional studies identified through hand searching of cited references and professional contacts.
Studies that provided data on the prevalence of SARS-CoV-2 in children and adolescents (younger than 20 years) compared with adults (20 years and older) derived from contact tracing or population screening were included. Single-household studies were excluded.
PRISMA guidelines for abstracting data were followed, which was performed independently by 2 reviewers. Quality was assessed using a critical appraisal checklist for prevalence studies. Random-effects meta-analysis was undertaken.
Secondary infection rate (contact-tracing studies) or prevalence or seroprevalence (population screening studies) among children and adolescents compared with adults.
A total of 32 studies comprising 41 640 children and adolescents and 268 945 adults met inclusion criteria, including 18 contact-tracing studies and 14 population screening studies. The pooled odds ratio of being an infected contact in children compared with adults was 0.56 (95% CI, 0.37-0.85), with substantial heterogeneity (I2 = 94.6%). Three school-based contact-tracing studies found minimal transmission from child or teacher index cases. Findings from population screening studies were heterogenous and were not suitable for meta-analysis. Most studies were consistent with lower seroprevalence in children compared with adults, although seroprevalence in adolescents appeared similar to adults.
In this meta-analysis, there is preliminary evidence that children and adolescents have lower susceptibility to SARS-CoV-2, with an odds ratio of 0.56 for being an infected contact compared with adults. There is weak evidence that children and adolescents play a lesser role than adults in transmission of SARS-CoV-2 at a population level. This study provides no information on the infectivity of children.
儿童和青少年感染严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）的程度尚不清楚。儿童和青少年在 SARS-CoV-2 传播中的作用取决于易感性、症状、病毒载量、社会接触模式和行为。
系统综述儿童和青少年与成年人相比感染和传播 SARS-CoV-2 的易感性。
从数据库建立到 2020 年 7 月 28 日，在 PubMed 和 medRxiv 上进行了搜索，共确定了 13926 项研究，并通过检索参考文献和专业联系进一步确定了其他研究。
纳入了提供了从接触者追踪或人群筛查中获得的儿童（<20 岁）与成人（20 岁及以上）相比 SARS-CoV-2 患病率数据的研究。单个家庭研究被排除在外。
按照提取数据的 PRISMA 指南进行，由 2 名评审员独立进行。使用流行研究的批判性评估清单评估质量。进行了随机效应荟萃分析。
与成年人相比，儿童和青少年的二次感染率（接触者追踪研究）或患病率或血清流行率（人群筛查研究）。
共纳入 32 项研究，包括 41640 名儿童和青少年和 268945 名成年人，包括 18 项接触者追踪研究和 14 项人群筛查研究。与成年人相比，儿童作为感染接触者的汇总优势比为 0.56（95%CI，0.37-0.85），存在很大的异质性（I2=94.6%）。三项基于学校的接触者追踪研究发现，儿童或教师索引病例的传播作用很小。人群筛查研究的结果存在异质性，不适合进行荟萃分析。大多数研究都表明儿童的血清流行率低于成年人，尽管青少年的血清流行率似乎与成年人相似。
在这项荟萃分析中，初步证据表明儿童和青少年对 SARS-CoV-2 的易感性较低，与成年人相比，作为感染接触者的优势比为 0.56。有微弱的证据表明，在人群层面上，儿童和青少年在 SARS-CoV-2 的传播中比成年人的作用更小。本研究没有提供有关儿童传染性的信息。
