Clinico-laboratory profile and outcome of Japanese encephalitis in Nepali children

Background: Japanese encephalitis (JE) is associated with high mortality and neurological sequelae. The unpredictable course and lack of specific treatment pose major challenges in management. The tropical climate and paddy ecosystem in Nepal provide a suitable setting. Aims: To determine the aetiology of febrile encephalopathy and describe the clinico-laboratory profile and outcome of JE in Nepali children. Methods: A hospital-based prospective and observational study was conducted over a 1-year period (2000-2001). Children aged from > 1 month to 14 years with fever > 38 degrees C for < 2 weeks and altered sensorium were recruited. JE was confirmed by anti-JE IgM in cerebrospinal fluid and/or serum. Results: Of 117 consecutively enrolled patients, 58 had JE. Ten patients had concomitant infections, four with malaria and six with bacterial meningitis, and were excluded from analysis. Clinical findings were as follows: boys, 69%; age 4-14 years, 71%; presentation during summer and autumn, 83%; fever > 3 days, 69%; altered sensorium,2 days, 50%; Glasgow coma score 8-12, 63%; seizures, 58%. Four (8.3%) died. At discharge, neurological sequelae were detected in 24 (50%) and hemiparesis was the most common form. Longer duration of vomiting, altered sensorium and focal neurological deficit on admission were independently associated with sequelae at discharge. Sequelae persisted in nine (18.8%) at 6 weeks follow-up. Long duration of altered sensorium (beta coefficient 0.35, odds ratio 1.4, p=0.042) and presence of focal neurological deficit on admission (beta co-efficient 1.6, odds ratio 5.2, p=0.049) were independent predictors of sequelae at 6 weeks. Conclusion: JE was the commonest cause of febrile encephalopathy. Neurological sequelae were common but resolved in two-thirds of cases.