Acute Encephalitis Syndrome in Children and Adolescents

Acute encephalitis syndrome (AES) in children can lead to severe neurocognitive deficits or death, making periodic studies crucial to track changes in causes and outcomes. A new study aimed to identify the etiological agents, diagnostic methods, treatments, and outcomes of AES in children.

Here, records of children aged 1 month to 15 yearswho were admitted with AES between 2015 and 2019 were reviewed. Clinical, laboratory, and radiological data were analyzed to determine outcomes – with poor outcomes defined as death, discharge with neurological deficits, or a Glasgow Outcome Score Extended (GOS-E) ≤ 5 at discharge.

The results showed that among 250 AES patients, 56.4% received a definitive diagnosis (30.4% viral, 22% bacterial), with scrub typhus (11.2%) and dengue (9%) being the most common causes. Serology confirmed diagnoses in 30% of cases. Of note, AES cases increased post-monsoon. Third-generation cephalosporins (85.7%) and acyclovir (77.7%) were the most used empirical treatments. Poor outcomes occurred in one-third of the children, with a Glasgow Coma Scale (GCS) ≤ 8 and the need for invasive ventilation as significant predictors.A definitive diagnosis was achieved in about half of the AES cases, with viral (30.4%) and rickettsial (22%) infections being the most common causes. 

Tests for Etiological Diagnosis in AES include:

• Bacterial: S. pneumoniae, Salmonella, Klebsiella, Enterococcus, H. influenzae type B, Neisseria meningitidis, Mycoplasma pneumoniae, Staphylococcus aureus, Acinetobacter spp., non-fermenting gram-negative bacilli (NFGNB).
• Viral: Dengue, Epstein Barr virus, Herpes Simplex virus, Influenza A and B, Mumps, Varicella Zoster virus, Cytomegalovirus, Enterovirus, Measles, Parainfluenza, Boca virus, Chikungunya.
• Fungal: Candida.
• Parasite: Cysticercosis.
• Autoimmune: Anti-NMDA receptor.
• Other: Scrub typhus (IgM+ Weil Felix OX K), Spotted fever (IgM+ Weil Felix OX 2/OX 19).
• Investigations include – CSF latex agglutination, blood cultures, Widal test, cold agglutinin, CSF PCR, and serology, depending on the suspected pathogen.

Source: Rebecca B, Thomas M, Abraham AM, et al. Indian Pediatrics. 2024 Apr 5:S097475591600624-