A Descriptive Epidemiological Study on Acute Encephalitis Syndrome and Japanese Encephalitis of Sonitpur District of Assam State of India from 2009 to 2016

Abstract

Introduction: Japanese Encephalitis (JE) commonly affects children and is a major cause of acute childhood encephalopathy. Growth of population, intensified rice farming, pig rearing and lack of surveillance are the key factor for transmission of the disease. Methods: The present study aimed at determining the Case Fatality Rate, Sample Positivity Rate (SPR) and distribution (Time, Place, and Person) of Acute Encephalitis Syndrome (AES) and JE cases in Sonitpur District of Assam, India. This descriptive study was conducted over 8 years' period (2009-2016), based on surveillance data corresponding to each year. Confirmation of JE was done by IgM ELISA method. Results: In the present study the CFR was highest for AES in the year 2015 being 11.1% and for JE it was 28% in the year 2015. Overall Sample Positivity Rate for JE was 18.35%. In this 8 years' study (from2009 to 2016), an almost equal sex distribution was observed in case of JE in Sonitpur District. Epi curve of AES cases of Sonitpur District showed two distinct peaks, one in the month of May and another in July. On the other hand, the Epi curve of JE cases showed a clear peak in the month of July in all these 8 years of study. Conclusion: JE is a predominant infection among children as well as among adult. But less than 6 years' age group was mostly affected. Highest peak has been observed in the month of July and May to August was the period of maximum JE cases and this isthe monsoon season in the district.