Original StudiesLong-term Mortality and Risk of Epilepsy in Children and Young Adults With Brain AbscessBodilsen, Jacob MD; Dalager-Pedersen, Michael MD, PhD; Nielsen, Henrik MDAuthor Information From the Department of Infectious Diseases, Aalborg University Hospital, Aalborg, Denmark. Accepted for publication March 28, 2020. The authors have no funding or conflicts of interest to disclose. J.B. designed the stud; collected, analyzed, and interpreted the data and wrote the first draft of the report. M.D.-P. and H.N. helped to design the study, interpret the data and reviewed the manuscript. The funder had no role in study design, data collection, analysis, interpretation or writing of the report. The corresponding author had full access to all the data in the study and had final responsibility for the decision to submit for publication. Address for correspondence: Jacob Bodilsen, MD, Department of Infectious Diseases, Aalborg University Hospital, Mølleparkvej 4, 9000 Aalborg, Denmark. E-mail: Jacob.firstname.lastname@example.org. The Pediatric Infectious Disease Journal: October 2020 - Volume 39 - Issue 10 - p 877-882 doi: 10.1097/INF.0000000000002736 Buy Metrics Abstract Background: The long-term prognosis of brain abscess is unclear. Methods: Using nationwide, population-based medical registries, we included all individuals <20 years of age hospitalized with first-time diagnosis of brain abscess in Denmark from 1982 to 2016. A comparison cohort individually matched for age, sex and residence was identified, as were siblings of all study participants. Next, cumulative incidence curves of mortality and new-onset epilepsy were constructed, and Cox regression was used for analyses of hazard rate ratios (HRRs) with 95% confidence intervals. Results: We identified 155 brain abscess patients and 1,550 population controls with median follow-up times of 15 years (interquartile range, 6–25) and 16 years (interquartile range, 11–26). Ear–nose–throat infections (22%) and congenital heart disease (13%) were the most common predisposing conditions for brain abscess. Overall mortality was 21/155 (14%) in brain abscess patients versus 20/1,550 (1%) in population controls. The corresponding HRRs were 150 (95% confidence interval: 19.8–1,116) after 1 year of observation, 24.6 (4.78–127) after 2–5 years and 0.66 (0.09–4.98) after 6–30 years. New-onset epilepsy occurred in 28% of 30-day brain abscess survivors versus 1% in population controls yielding a HRR of 29.6 (14.4–60.8) adjusted for previous head trauma, stroke and cancer. Analyses of sibling cohorts showed that family-related factors did not explain the observed increased risks of death or epilepsy among brain abscess patients. Conclusions: Brain abscess is associated with increased risk of mortality for up to 5 years. New-onset epilepsy occurred in 28% of survivors and remained a risk for several years after infection. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.