%0 Journal Article
%T Temporal patterns of asymptomatic SARS-CoV-2 infection among pediatric population in Japan: A 3-year analysis.
%A Kozawa K
%A Higashimoto Y
%A Kawamura Y
%A Miura H
%A Hattori F
%A Mihara Y
%A Nakai H
%A Nishimura N
%A Ozaki T
%A Ihira M
%A Yoshikawa T
%J J Med Virol
%V 96
%N 8
%D 2024 Aug
%M 39105394
%F 20.693
%R 10.1002/jmv.29847
%X 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.