Clinical and prognostic features among children with acute encephalitis syndrome in Nepal; a retrospective study

BACKGROUND: Acute encephalitis syndrome (AES) is commonly seen among hospitalized Nepali children. Japanese Encephalitis (JE) accounts for approximately one-quarter of cases. Although poor prognostic features for JE have been identified, and guide management, relatively little is reported on the remaining three-quarters of AES cases. METHODS: Children with AES (n = 225) were identified through admission records from two hospitals in Kathmandu between 2006 and 2008. Patients without available lumbar puncture results (n = 40) or with bacterial or plasmodium infection (n = 40) were analysed separately. The remaining AES patients with suspected viral aetiology were classified, based on positive IgM antibody in serum or cerebral spinal fluid, as JE (n = 42) or AES of unknown viral aetiology (n = 103); this latter group was sub-classified into Non-JE (n = 44) or JE status unknown (n = 59). Bad outcome was defined as death or neurological sequelae at discharge. RESULTS: AES patients of suspected viral aetiology more frequently had a bad outcome than those with bacterial or plasmodium infection (31% versus 13%; P = 0.039). JE patients more frequently had a bad outcome than those with AES of unknown viral aetiology (48% versus 24%; P = 0.01). Bad outcome was independently associated in both JE and suspected viral aetiology groups with a longer duration of fever pre-admission (P = 0.007; P = 0.002 respectively) and greater impairment of consciousness (P = 0.02; P < 0.001). A higher proportion of JE patients presented with a focal neurological deficit compared to patients of unknown viral aetiology (13/40 versus 11/103; P = 0.005). JE patients weighed less (P = 0.03) and exhibited a higher respiratory rate (P = 0.003) compared to Non-JE patients. CONCLUSIONS: Nepali children with AES of suspected viral aetiology or with JE frequently suffered a bad outcome. Despite no specific treatment, patients who experienced a shorter duration of fever before hospital admission more frequently recovered completely. Prompt referral may allow AES patients to receive potentially life-saving supportive management. Previous studies have indicated supportive management, such as fluid provision, is associated with better outcome in JE. The lower weight and higher respiratory rate among JE patients may reflect multiple clinical complications, including dehydration. The findings suggest a more systematic investigation of the influence of supportive management on outcome in AES is warranted.