Japanese encephalitis epidemiology in Arunachal Pradesh, a hilly state in northeast India

ObjectiveTo confirm Japanese encephalitis (JE) cases from the state of Arunachal Pradesh (AP), India for the first time.MethodsSuspected acute encephalitis syndrome (AES) cases were screened from 2005-2010. The cases were initially tested for antibodies against JE by using IgM MAC ELISA kits (National Institute of Virology, Pune). RNA was extracted from the cerebrospinal fluid (CSF) samples followed by molecular amplification of JE virus specific gene primer. The data obtained were used to calculate relative risks between the age groups and between the genders. Epi info 6.0 was used for the statistical analysis.ResultsPresence of JE cases in the state of AP, India was established. JE cases from 10 out of 16 districts were recorded. As part of control and preventive measures, mass vaccination for children (0-15 years) by SA-14-14-2 JE vaccine was taken up in 2010 in the district of Lohit. Vaccination coverage of 83.09% among the target population was achieved.ConclusionsThe study presents the first report of confirmed JE cases from the state of AP, India. This finding attracts attention as JE cases are rarely seen to occur in hilly places.