Abstract：
To elucidate the seroprevalence and rate of asymptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Japanese children, serological analysis was performed using serum samples collected from March 2020 to February 2023. A total of 1493 serum samples were collected during the first study period (March 2020 to February 2021). None of the serum samples was positive for SARS-CoV-2 antibody. In the second period (March 2021 to February 2022), seven of the 1055 patients (0.7%) experienced SARS-CoV-2 infection. The third period (March 2022 to February 2023) was divided into three terms: from March to June 30, 2022; from July to October 2022; and from November 2022 to February 2023. The seroprevalence gradually increased throughout this period, with rates of 6.0%, 18.6%, and 30.4% in the three terms, respectively. Pediatric cases of asymptomatic SARS-CoV-2 infection occurred after the surge of Omicron variants. Since none of the SARS-CoV-2 antibody-positive patients had a previous history of coronavirus disease 2019, the seroprevalence rate in this study may represent the rate of asymptomatic infection.
摘要：
阐明日本儿童中严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的血清阳性率和无症状感染率，血清学分析使用从2020年3月至2023年2月收集的血清样本进行.在第一个研究期间（2020年3月至2021年2月）共收集了1493份血清样品。血清样品中没有SARS-CoV-2抗体阳性。在第二阶段（2021年3月至2022年2月），1055名患者中有7名(0.7%)经历了SARS-CoV-2感染。第三阶段（2022年3月至2023年2月）分为三个期限：2022年3月至6月30日；2022年7月至10月；以及2022年11月至2023年2月。在此期间血清阳性率逐渐增加，比率为6.0%，18.6%,在三项中占30.4%，分别。无症状的SARS-CoV-2感染的儿科病例发生在Omicron变体激增之后。由于SARS-CoV-2抗体阳性患者均无2019年冠状病毒病史，因此本研究中的血清阳性率可能代表无症状感染率。
