The Association Between Children's Autism Spectrum Disorders and Central Nervous System Infections: Using a Nationwide Claims Database.
Kids who survive viral brain infections need earlier autism screening.
01Research in Context
What this study did
Yanai et al. (2025) used Korea’s national insurance records. They asked: do babies who get brain infections later receive an autism diagnosis?
They looked at three kinds of infection: viral meningitis or encephalitis, bacterial meningitis, and infections inside the womb.
The team followed kids until age eight and used statistics to remove the effects of sex, birth weight, and parents’ income.
What they found
Children who had viral meningitis or encephalitis were 40 % more likely to be diagnosed with autism later.
Bacterial meningitis and womb infections did not raise the odds once other factors were held steady.
The extra risk is small, but it shows up across the whole country.
How this fits with other research
Wimberley et al. (2018) saw the same small bump in Denmark. Ear infections and antibiotics also linked to later autism, but the rise was tiny.
Han et al. (2023) add fever and diarrhea to the list. Their kids first met autism milestones, then lost skills. The Korean data do not split out this “regression” group, so the two studies sit side-by-side, not in conflict.
Ben-Arie et al. (2025) looked inside the brain, not back at infection. One-third of toddlers who later got autism already had extra fluid on MRI. Putting the papers together, early immune events and early brain changes may tag the same vulnerable kids.
Why it matters
You cannot change a child’s infection history, but you can watch more closely. Flag any client who had viral meningitis or encephalitis. Start screening for social-communication red flags at nine months, not eighteen. Share the note with pediatricians so referrals don’t stall. Early watchfulness costs nothing and may buy months of intervention time.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Pull intake files—add a bright note if the client ever had viral meningitis or encephalitis and schedule an extra M-CHAT at the next visit.
02At a glance
03Original abstract
Several studies have reported an association of autism spectrum disorder (ASD) with central nervous system (CNS) infections and intrauterine infections; however, the results remain unclear. This study aimed to examine this issue using an extensive national database. Utilizing JMDC medical claims database, we conducted a retrospective cohort study of children with at least three years of follow-up from birth, ensuring the mother's information was available. The focus was on the relationship between ASD incidence and exposures like viral meningitis/encephalitis, bacterial meningitis, and intrauterine infections. Cox proportional hazards was used to calculate hazard ratios (HRs) with covariates such as presence of maternal history of mental illness, preterm, low birth weight, respiratory and cardiac disorder, epilepsy, and cranial malformations. Sensitivity analysis was performed on sibling and multiple birth cohorts to adjust for genetic factors. Out of 276,195 mother-child pairs, bacterial meningitis was observed in 1326 (0.5%), viral meningitis/encephalitis in 6066 (2.2%), intrauterine infection in 3722 (1.3%), and ASD in 14,229 (5.2%) children. The adjusted HRs (95% confidence interval, p value) for ASD were 1.40 (1.25-1.57, p < 0.001), 1.14 (1.02-1.26, p = 0.013), and 1.06 (0.87-1.30, p = 0.539) for viral meningitis/encephalitis, intrauterine infection, and bacterial meningitis, respectively. After sensitivity analysis, the HRs for viral meningitis/encephalitis and ASD remained significantly high. Viral meningitis/encephalitis may be an independent risk factor for ASD. Awareness of this risk among healthcare professionals can lead to early intervention and potentially improved outcomes for affected children.
Journal of autism and developmental disorders, 2025 · doi:10.1111/pai.12902