COVID-19 outbreak on the seasonality and incidence of pediatric type 1 diabetes mellitus.

To respond to the recent study by Carmon et al on type 1 diabetes (T1DM) incidence/seasonality pre-coronavirus disease 2019 and peri-coronavirus disease 2019, we highlighted convergent findings from the Lombardy pediatric T1DM data (2017-2023). Carmon et al reported elevated T1DM incidence and lost seasonality in the pandemic first year in Israel, linking respiratory viral disruption to T1DM risk. Our data show a 2020 step-increase in Lombardy pediatric T1DM and stable elevated rates (2020-2023) unrelated to coronavirus disease 2021 vaccines. Combined Israeli-Italian data suggest the pandemic triggered lasting higher pediatric T1DM incidence, potentially via severe acute respiratory syndrome coronavirus 2-mediated beta cell damage or immunological shifts, emphasizing global surveillance needs for pandemic autoimmune disease links.