Abstract
OBJECTIVE: Japanese encephalitis (JE) is one of the most important causes of viral encephalitis in Uttar Pradesh (UP). Over 5 years (2018-2022), this study aims to find out the seropositivity for JEV in cases presenting as AES. MATERIALS AND METHODS: Over 5 years, 8131 cerebrospinal fluid and 504 serum samples were tested for anti-JEV Immunoglobulin M (IgM) antibodies by IgM antibody capture (MAC) enzyme-linked immunosorbent assay (ELISA) according to the manufacturer's instructions (MAC ELISA kit developed by the National Institute of Virology, Pune, India. RESULTS: A total of 526 cases (6.09%) tested positive for anti-JEV IgM antibodies during the study periods. The number of JEV positives was high in 2018 (11.25%) but decreased gradually over the next 5 years (2019 (5.71%), 2020 (5.22%), 2021 (4.36%), and 2022 (2.91%). JE positivity is declining over time in UP, India. There is an age shift from children to adults. Men are more often affected than women. CONCLUSION: Further JE-centric studies with an emphasis on immunization are required to determine the influence of vaccination on the incidence of Japanese encephalitis and the population shift among adults.