Hospital based surveillance for Japanese encephalitis in Lucknow, India – 2011–2013: Need for more JE vaccination?

IntroductionAcute encephalitis syndrome (AES) continues to occur in the state of Uttar Pradesh in northern India despite the vaccination drives against Japanese encephalitis (JE) in recent years. The prevalence of JE has decreased in other regions of the state which were hitherto the epicenter of this infection.ObjectiveTo conduct a hospital based surveillance for JE from among children presenting with AES in Lucknow, the capital of Uttar Pradesh.MethodologyChildren between 6 months and 14 years of age admitted with AES to the Childrens' wards of out teaching hospital in Lucknow, over a period of 29 months (July 2011–November 2013) were subjected to a standardized work up. IgM antibodies against JE in cerebrospinal fluid and serum were tested for by the Panbio Combo (JE & Dengue) kit and National Institute of Virology ELISA kit.ResultsA total of 1586 patients with AES were admitted to the pediatric wards in the study period, of which 1070 were tested for JEV IgM and 238 (22.2%) were positive. JE positivity was found almost exclusively in monsoon and postmonsoon season and patients came from 22 surrounding districts.ConclusionsAES and JE continue to be an important cause of hospitalization in children in Lucknow, which highlights the need for further vaccination drives in this region.