ESTIMATING THE ASSOCIATION BETWEEN ACUTE SARS-CoV-2 AND FEBRILE SEIZURE IN CHILDREN USING THE CANADIAN IMMUNIZATION MONITORING PROGRAM-ACTIVE (IMPACT)

Abstract

This study investigated the association between acute SARS-CoV-2, influenza, respiratory syncytial virus (RSV), enterovirus/rhinovirus infections, and hospitalization for febrile seizures in children aged <7 years. Conducted in 11 Canadian Immunization Monitoring Program-Active (IMPACT) centers from Aug 2021 to Dec 2022, the prospective surveillance included 3,306 subjects with febrile seizures. The association was measured with a cohort study design and mixed-effects logistic regression. While 18% required hospitalization, differential testing for SARS-CoV-2 (87% hospitalized vs. 26% non-hospitalized) revealed significant bias. Hospitalization with febrile seizure and SARS-COV-2 testing varied across IMPACT centers and during the Omicron period. Adjusting for confounders, the study could not validly estimate the association due to extensive misclassification bias in non-hospitalized cases. Limited testing in non-hospitalized patients highlighted the need for a more systematic approach, while variations in hospitalization and testing practices underscored the importance of exploring and addressing these discrepancies in future research.