A comparison of clinical features of Japanese encephalitis virus infection in the adult and pediatric age group with Acute Encephalitis Syndrome

Background: Japanese encephalitis (JE) has traditionally been regarded as a disease of children. The age shift in JE patients in Assam, India in last few years has become a cause of concern. Comparison on clinical features of adult and pediatric JE patients has not been evaluated. Objective: To compare clinical features of adult and pediatric with JE virus infection. Study design: From January 2008 to January 2010, 550 hospitalized patients with Acute Encephalitis Syndrome were enrolled. 259 (47.1%) were serologically confirmed as JE of which 66.4% were adult and 33.6% were pediatric. Data extracted from these patients were analyzed. Results: Fever was the most common symptom in both the adult and pediatric. When compared with adult, significantly higher percentage of pediatric had neck rigidity, convulsions, abnormal behavior, seizures and elevated aspartate transaminase (P < 0.05). Serum bilirubin levels were higher in 2.3% of adult but normal in all the pediatric. We found significantly higher mean elevated level of protein and WBC in CSF in adult (P < 0.001) and mean elevated aspartate transaminase level (P < 0.001) in pediatrics. There was no difference in mortality rate between pediatric and adult (8.2% vs. 4.4%, P = 0.647). Conclusions: This study provides some significant differences in clinical features of pediatric and adult with JE. Age shift may be due to the invasion of the disease into new demography or some change in the virus strain over time. The Government of India has initiated an adult JE vaccination programme for the first time in Assam in 2011. (C) 2011 Elsevier B.V. All rights reserved.