Epidemiological and clinical evolution of multisystem inflammatory syndrome in children throughout the SARS‐CoV‐2 pandemic in a tertiary Italian children's hospital

Abstract

AbstractMultisystem inflammatory syndrome in children (MIS‐C) is a potentially life‐threatening disease temporally linked to SARS‐CoV‐2 whose incidence and clinical presentation may have been altered by the different SARS‐CoV‐2 variants and by vaccination.MethodsWe retrospectively collected the data of all MIS‐C cases admitted to the Gaslini Children's Hospital, the hub for SARS‐CoV‐2 related diseases in Liguria region, Italy, from 01 October 2020, to 30 November 2022, evaluating the ratio between MIS‐C cases and (1) COVID‐19 paediatric cases in our region, (2) emergency department admissions and (3) emergency department febrile patients. We also compared MIS‐C incidence in pre‐ post‐vaccination periods.ResultsWe observed a significant global decline in the incidence of MIS‐Cover the four variant periods and after the starting of vaccination whereas clinical features, therapeutic management and severity did not significantly vary.ConclusionsIn our setting, we demonstrated a significant decrease of MIS‐C incidence according to the predominant variant and including not vaccinated children. Regardless of variant type, the patients showed similar phenotypes and severity throughout the pandemic. SARS‐CoV‐2 variants as well as immune protection after previous infections and/or vaccination may have interacted by playing different roles and reducing the incidence of MIS‐C.