the hot and humid summer monsoon seasons. Japanese encephalitis (JE) is a major public health problem in India because of high mortality rate and

residual neuropsychiatric damage in the survivors. The present study was undertaken to investigate JE positivity amongst patients admitted with acute

encephalitis syndrome (AES) in southern part of Assam and adjoining states and different parameters like demographic profile of JE amongst the

population, seasonal and geographical distribution of JE cases from a tertiary care hospital in South Assam with their changing trends related to it.

Methods: It was a hospital–based prospective cross–sectional study conducted from the month of july’2013 to the month of September’2015 in the

department of Microbiology, Silchar Medical College, Assam. CerebroSpinalFluid and serum samples were collected from clinically suspected

AES cases and tested for IgM antibody against JE by JE MAC ELISA.

Result: Out of total 341 AES cases ,77 ( 22.5 %) were positive for JE. Detection rate of JE was 35.5%, 12.7%, and 22.6% in the years 2013, 2014,

and 2015 respectively. The JE positivity was much higher(26.27%) in adult, than in paediatric population(14.27%).Significant numbers of JE cases

were found to be clustered around the monsoon season.