2333. Influenza-Related Neurologic Complications in Hospitalized Children with Underlying Neurologic Disorders

BACKGROUND: Children with underlying neurological and neuromuscular conditions are considered “high risk” for developing severe infection due to influenza. Prior reports highlighted this population’s increased risk for respiratory failure. Little is known about neurological complications experienced by children with pre-existing neurologic disorders (PNDs) when infected with influenza. METHODS: Retrospective cohort study of children 0.5–18.0 years old hospitalized at a tertiary care pediatric hospital between August 2010 and June 2017 with laboratory-confirmed influenza. Eligible children were identified by electronic medical record query for influenza assay CPT codes with positive results during an admission; cases were confirmed by chart review. Demographics and clinical data were abstracted. RESULTS: A total of 1217 immune competent children (median age 5.5 [IQR 2.2–9.8] years) were hospitalized with laboratory-confirmed influenza during the study period. About 28% (341/1217) had at least one PND, including epilepsy (n = 105), developmental delay or intellectual disability (n = 234), neurogenetic or metabolic disorders (n = 77), neuromuscular disorders (n = 22) and others (n = 253). Compared with previously healthy peers, these children were more often admitted to the intensive care unit (31% vs. 16%, P < 0.001), had a longer length of stay (3 vs. 2 days, P < 0.001), and had a higher incidence of neurologic complications (23% vs. 6%, P < 0.001). Seizures (18% vs. 4%, P < 0.001) and encephalopathy (8% vs. 2%, P < 0.001) in particular were more common in children with PNDs, but other neurologic complications occurred in comparable proportions (3% vs. 1%, P = 0.088). Only 49% of the overall cohort had documented annual influenza vaccine; coverage was slightly better for children with PNDs than those without (55% vs. 48%, P = 0.017). The odds of having a neurologic complication in children with documented vaccination was nearly half that of other children when adjusted for age, influenza strain, and any PND (adjusted OR 0.64, 95% CI 0.44–0.94, P = 0.021). CONCLUSION: The excess risk of neurological complications in children with PNDs highlights the importance of vaccinating this population. Additional consideration should be given to post-exposure prophylaxis for children with PNDs who have not received vaccine. [Image: see text] DISCLOSURES: All authors: No reported disclosures.