Table1_Analysis of the impact of the SARS-CoV-2 infection on the pediatric population hospitalized during the pandemic in the Greater Paris University Hospitals.docx

BackgroundThe clinical characteristics, disease progression and outcome in children affected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection appear significantly milder compared to older individuals. Nevertheless, the trends in hospitalization and clinical characteristics in the pediatric population seem to be different over time across the different epidemic waves.
ObjectiveOur aim was to understand the impact of the different COVID-19 variants in the pediatric population hospitalized in the Pediatric Departments of the Public Hospital in the Greater Paris area by the analysis performed with the Assistance Publique-Hopitaux de Paris (AP-HP) Health Data Warehouse.
MethodsThis is a retrospective cohort study including 9,163 patients under 18 years of age, hospitalized from 1 March 2020 to 22 March 2022, in the Paris area, with confirmed infection by SARS-CoV-2. Three mutually exclusive groups with decreasing severity (Pediatric Inflammatory Multisystem Syndrome (PIMS), symptomatic infection, mild or asymptomatic infection) were defined and described regarding demography, medical history, complication of the SARS-CoV-2 infection, and treatment during admission. Temporal evolution was described by defining three successive waves (March–September 2020, October 2020–October 2021, and November 2021–March 2022) corresponding to the emergence of the successive variants.
ResultsIn the study period, 9,163 pediatric patients with SARS-CoV-2 infection were hospitalized in 21 AP-HP hospitals. The number of patients with SARS-CoV-2 infection increased over time for each wave of the pandemic (the mean number of patients per month during the first wave was 332, 322 during the 2nd, and 595 during the third wave). In the medical history, the most associated concomitant disease was chronic respiratory disease. Patients hospitalized during the third wave presented a higher incidence of pulmonary involvement (10.2% compared to 7% and 6.5% during the first and second waves, respectively). The highest incidence of PIMS was observed during the first and second waves (4.2% in the first and second waves compared to 2.3% in the 3rd wave).
DiscussionThis analysis highlighted the high incidence of hospitalized children in the Greater Paris Area during the third wave of SARS-CoV-2 pandemic corresponding to the Omicron Covid-19 variant, which is probably an expression of a concomitant SARS-CoV-2, while a decreased incidence of PIMS complication was observed during the same period.

背景：与年长人群相比，感染严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的儿童的临床特征、疾病进程及转归均显著更轻微。然而，不同疫情波次下，儿科人群的住院趋势与临床特征随时间推移呈现出明显差异。
研究目的：本研究借助巴黎公共援助医院（Assistance Publique-Hôpitaux de Paris, AP-HP）健康数据仓库开展分析，旨在探究不同COVID-19变异株对大巴黎地区公立医院儿科科室收治的住院患儿的影响。
研究方法：本研究为回顾性队列研究，纳入2020年3月1日至2022年3月22日期间巴黎地区住院的9163名18岁以下确诊感染SARS-CoV-2的患儿。本研究按病情严重程度由高到低划分了三个互斥组别：儿童多系统炎症综合征（Pediatric Inflammatory Multisystem Syndrome, PIMS）、有症状感染、轻症或无症状感染，并从人口学特征、病史、SARS-CoV-2感染相关并发症及住院治疗方案四个维度对各组进行描述。此外，本研究将研究周期划分为三个连续疫情波次（2020年3月—2020年9月、2020年10月—2021年10月、2021年11月—2022年3月），以对应不同变异株的出现时间，描述疫情随时间的演变情况。
研究结果：本研究周期内，共计21家AP-HP医院收治了9163名感染SARS-CoV-2的儿科住院患儿。随着疫情波次推进，新冠大流行各波次的住院患儿数量逐步上升：第一波次月均收治患儿332例，第二波次为322例，第三波次则达到595例。病史分析显示，最常见的合并基础疾病为慢性呼吸系统疾病。第三波次住院患儿的肺部受累发生率更高（10.2%，第一、第二波次分别为7%与6.5%）。儿童多系统炎症综合征（PIMS）的最高发生率出现在第一、第二波次（两波次均为4.2%，第三波次仅为2.3%）。
讨论：本分析显示，在对应奥密克戎（Omicron）COVID-19变异株的新冠大流行第三波次中，大巴黎地区住院感染患儿的发生率居高不下，这或许与同期流行的SARS-CoV-2毒株相关；而同期儿童多系统炎症综合征（PIMS）并发症的发生率则有所下降。