055 - Infectious and Non-infectious Etiologies of Acute Encephalitis in Children in Atlanta, Georgia, 2018-2024

Publication Number: 55.5555

Amy M. Bohling, Emory University School of Medicine, Atlanta, GA, United States; Morgan Morris, Emory University School of Medicine, Atlanta, GA, United States; Ashley Tippett, Emory University School of Medicine, Atlanta, GA, United States; Arpit Dosanjh, Children's Healthcare of Atlanta, Atlanta, GA, United States; Adam E.. Goldman-Yassen, Children’s Healthcare of Atlanta and Emory University School of Medicine, Atlanta, GA, United States; Grace Y.. Gombolay, Emory University School of Medicine, Atlanta, GA, United States; Christina Rostad, Emory, Atlanta, GA, United States

Background: Understanding the epidemiology and features of acute encephalitis in children could facilitate timely diagnosis and optimal treatment.

Objective: We hypothesize that there are differentiating clinical, laboratory, and imaging features and baseline risk factors that are predictive of a diagnosis of acute infectious encephalitis and that distinguish from autoimmune encephalitis at the time of clinical presentation.

Design/Methods: We screened children who had magnetic resonance imaging results with key words “encephalitis” or “meningoencephalitis” at Children’s Healthcare of Atlanta to identify those 1 to 18 years of age (inclusive) who were hospitalized between 2018 and 2024 and met clinical diagnostic criteria for acute encephalitis. We performed retrospective chart review to abstract demographic and epidemiologic data and analyzed by descriptive statistics. Groups were compared using Chi-square or unpaired t-tests. P< 0.05 was considered statistically significant.

Results: 124 children met clinical criteria and were included in the analysis. Of these, 38 (31%) had infectious etiologies, 42 (34%) autoimmune, and 44 (35%) other or unknown etiologies. Of the infections, 34 were viral infections, the most common of which was influenza (n=9). Of those with autoimmune encephalitis, the most common etiology was anti-MOG (n=22) followed by anti-NMDA-R (n=19). Compared to infectious encephalitis, children with autoimmune encephalitis were significantly older (median age 9.4 (IQR 5.2, 11.5) vs 6.2 (IQR 2.8, 11.3), p=0.010), more commonly female (69% vs 50%, p=0.083), and non-white race (64% vs 50%, p=0.197). Children with infectious encephalitis presented more commonly with fever (86% vs 38%, p< 0.001), but similar rates of seizures as those with autoimmune encephalitis (58% vs 58%, p=0.968).

Conclusion(s): Infectious, autoimmune, and unknown/other etiologies each accounted for approximately one third of acute encephalitis diagnoses in children and were associated with differences in baseline demographics and presenting clinical features.