Study of Japanese encephalitis and other viral encephalitis in Nepali children

Background: A hospital-based prospective cross-sectional study was conducted in children aged 1 month-14 years to identify the proportion of viral encephalitis due to Japanese encephalitis (JE) and compare the clinico-laboratory profile and outcome of JE with that of other viral encephalitis (non-JE). Methods: All probable cases of viral encephalitis on clinical and laboratory evaluation were confirmed as JE on anti-JE IgM in cerebrospinal fluid (CSF) and/or serum. Patients not having anti-JE IgM in CSF and/or serum were diagnosed as having non-JE. Results: Of 94 cases, 58 were JE and 36 non-JE. Although practice of rearing pigs at home was associated with JE (P = 0.0001), significantly higher serum creatinine, protein, aspartate aminotransferase and CSF protein levels were observed in non-JE. Longer duration of fever was associated with complete recovery in JE whereas shorter duration of fever was associated with recovery in non-JE. Risk of neurological sequelae (P = 0.01), especially hemiparesis (P = 0.03) was significantly more in JE. Sequelae were observed at 6 weeks follow up in 18.8% of JE and 13.9% of non-JE. Conclusion: JE was the most common cause of viral encephalitis in eastern Nepal and should be suspected in encephalitic patients having pig rearing at home and neurological sequelae. Although duration of hospitalization and complication were higher in JE, final outcome was similar to non-JE. Longer duration of fever in JE and shorter duration of fever in non-JE correlated with recovery, while altered sensorium and focal neurological deficit were independent predictors of sequelae at 6 weeks only in JE and not in non-JE.