A population-based serological study of post-COVID syndrome prevalence and risk factors in children and adolescents

Abstract

Post-COVID syndrome remains poorly studied in children and adolescents. Here, we aimed to investigate the prevalence and risk factors of pediatric post-COVID in a population-based sample, stratifying by serological status. Children from the SEROCoV-KIDS cohort study (State of Geneva, Switzerland), aged 6 months to 17 years, were tested for anti-SARS-CoV-2 N antibodies (December 2021-February 2022) and parents filled in a questionnaire on persistent symptoms in their children (lasting over 12 weeks) compatible with post-COVID. Of 1034 children tested, 570 (55.1%) were seropositive. The sex- and age-adjusted prevalence of persistent symptoms among seropositive children was 9.1% (95%CI: 6.7;11.8) and 5.0% (95%CI: 3.0;7.1) among seronegatives, with an adjusted prevalence difference (ΔaPrev) of 4.1% (95%CI: 1.1;7.3). Stratifying per age group, only adolescents displayed a substantial risk of having post-COVID symptoms (ΔaPrev = 8.3%, 95%CI: 3.5;13.5). Identified risk factors for post-COVID syndrome were older age, having a lower socioeconomic status and suffering from chronic health conditions, especially asthma. Our findings show that a significant proportion of seropositive children, particularly adolescents, experienced persistent COVID symptoms. While there is a need for further investigations, growing evidence of pediatric post-COVID urges early screening and primary care management.

Fig. 1. Participants recruitment and inclusion into analytical sample.

The Flowchart illustrates the process of recruitment and participation.

Fig. 2. Sex- and age- adjusted difference (%) of symptoms lasting over 12 weeks between seropositive and seronegative children, December- February 2022, Geneva, Switzerland.

Sample size: 79 children and adolescents whom experienced symptoms lasting over 12 week. The colored dots refer to types of symptoms, as presented in the legend. Data are presented as mean values of the differences between seropositive and seronegative children with +/−Standard Error of the Mean (SEM), illustrated by the error bars.