Influenza-Related Encephalopathy in Children: Epidemiology and Literature Review from a Tertiary Hospital in Northern Italy (Winter 2023-2024)

Pathogens. 2025 Jun 1;14(6):551. doi: 10.3390/pathogens14060551.

Abstract

Introduction: While influenza-associated encephalopathy (IAE) in children remains a serious concern, recent evidence suggests a shift in its epidemiology, with a possible decline in incidence and severity over time.

Methods: This retrospective review includes patients aged 0-18 admitted to a tertiary hospital in Northern Italy between November 2023 and February 2025. Inclusion criteria were a positive influenza test, influenza-like symptoms, and neurological involvement. Findings are interpreted alongside current literature.

Results: Twenty-five unvaccinated children met criteria for IAE (11 in 2023/24; 14 in 2024/25). Neurological comorbidities were present in 40%. All patients had pathological EEGs. Lumbar puncture was performed in 40%, with abnormalities in 33%. Brain imaging was conducted in 56% of cases, revealing findings in 15%. All received oseltamivir; 60% were also treated with dexamethasone. Severe complications occurred in 16%, while 12% had persistent symptoms or required therapy at discharge. After adjusting for seasonal peak timing, no significant inter-seasonal difference was observed.

Discussion: Although IAE continues to present serious risks, recent trends suggest a changing burden. The lack of vaccination among cases underscores the need for prevention. Study limitations include its single-center design and the absence of long-term follow-up. Broader prospective studies are needed.

Keywords: children; encephalitis; encephalopathy; influenza; necrotizing encephalitis.

Publication types

  • Review

MeSH terms

  • Adolescent
  • Antiviral Agents / therapeutic use
  • Brain Diseases* / epidemiology
  • Brain Diseases* / etiology
  • Brain Diseases* / virology
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Incidence
  • Infant
  • Infant, Newborn
  • Influenza, Human* / complications
  • Influenza, Human* / epidemiology
  • Italy / epidemiology
  • Male
  • Oseltamivir / therapeutic use
  • Retrospective Studies
  • Seasons
  • Tertiary Care Centers

Substances

  • Antiviral Agents
  • Oseltamivir