Risk of psychiatric neurodevelopmental disorders after meningitis in childhood: a nationwide, population-based cohort study.

Background: Few studies have investigated the risk of psychiatric neurodevelopmental disorders (PNDD) after childhood meningitis.
Methods: Nationwide population-based cohort study (Denmark, 1995-2021) of children with positive cerebrospinal fluid for bacteria or enterovirus, stratified on age as young infants (0 to <90 days, n  = 637) or older children (≥90 days to <17 years, n  = 1,218). We constructed a comparison cohort from the general population ( n  = 18,550), and cohorts of siblings of participants. As risk estimates of PNDD we calculated age- and sex-adjusted hazard ratios (aHRs) with 95% confidence intervals (95%CI).
Results: Children with bacterial meningitis had increased risks of PNDD, especially learning and intellectual developmental disorders (young infants: aHR 4.2, 95%CI: 2.4-7.1; older children: aHR 1.5, 95%CI: 1.0-2.3), attention deficit disorder (ADHD) (young infants: aHR 2.8, 95%CI: 1.5-5.2; older children: 1.4, 95%CI: 0.9-2.2) and redemption of ADHD medication (young infants: aHR 2.2, 95%CI: 1.0-4.7; older children: 1.5, 95%CI: 1.0-2.3). Young infants with bacterial meningitis additionally had increased risks of autism spectrum disorders (aHR 1.9, 95%CI: 0.9-4.1) and behavioural and emotional disorders (aHR 2.0, 95%CI: 1.0-3.9). In young infants, the excess risk of PNDD was especially observed in premature children. Siblings of older children with bacterial meningitis also had increased risks of PNDD. Children with enteroviral meningitis at any age did not have increased risks of PNDD or redemption of ADHD medication.
Conclusions: Bacterial meningitis in childhood is associated with subsequent diagnosis of PNDD, while enteroviral meningitis is not. The association appears to be partly explained by prematurity and familial and socioeconomic factors.