PurposeJapanese encephalitis (JE) has emerged as a major public health concern in North East India due to its complex eco-epidemiological risk factors. The objective of this study was to understand the various risk factors associated with JE infection in the endemic study location.Methods A hospital-based case-control study was conducted at Jorhat Medical College and Hospital from August 2017 to September 2018. The study participants included 49 confirmed JE cases with two control arms, one consisting of non-JE acute encephalitis syndrome (AES) patients (n = 91) and the other of non-JE non-AES patients (n = 140), admitted at the same time in the pediatric and medicine wards. A predesigned, pretested, structured questionnaire was used for data collection. ResultsUnivariate analysis revealed the following to be risk factors: age at onset, sex, religion, immunization status, proximity to pigs, proximity to paddy fields (<100 m), use of a mosquito net, impregnated mosquito net, mosquito repellent, and outdoor activities. Multiple logistic regression analysis identified age at onset (adjusted odds ratio [AOR], 20.900; 95% confidence interval [CI], 2.210–31.815) and proximity to pigs (AOR, 4.190; 95% CI, 1.592–11.040) as risk factors for the first control arm and proximity to paddy fields (<100 m) (AOR, 8.470; 95% CI, 2.0251–35.438) was the only risk factor found for second control arm, whereas impregnated mosquito nets (AOR, 0.082; 95% CI, 0.009–0.725) and mosquito repellent (AOR, 0.173; 95% CI, 0.052–0.575) were found to be associated with the second control arm.ConclusionAge at onset, proximity to pigs, proximity to paddy fields (<100 m), impregnated mosquito nets, and mosquito repellent were the most significant risk factors for JE in the NE region to warrant public health actions.

Acute Encephalitis Syndrome (AES) is a major public health problem and Japanese Encephalitis (JE) is one of the most important causes of AES. Therefore, it is crucial to know the etiology of AES for patient management and decision making. The present study aimed to assess the morbidity and mortality prole of AES/JE patients admitted in tertiary care setting. An observational prospective cross-sectional study was conducted among 140 hospitalized AES patients admitted in Pediatric and Medicine ward of Jorhat Medical College and Hospital (JMCH), Jorhat over a period from August, 2017 to July 2018. Blood serum and cerebrospinal uids (CSF) were tested for presence of JE specic IgM antibody by Mac ELISA during acute illness of AES. The data were compiled and analyzed using the IBM SPSS, V23.0. Of the total 140 AES cases, majority (60%) were below 15 years age (p-value 0.180). Signicantly higher proportion of AES cases were from rural areas (94.3%) (p-value <0.0001). The male and female ratio was 1.3:1. The most common presenting symptoms in AES patients were fever (100%), change in mental status (100%), seizure (56.4%) and headache (42.9%). Signs of meningeal irritation were present in 69.3% of cases. Around 22.9% AES patients had GCS ≤ 8. A total 49 (35%) cases were found to be laboratory conrmed JE following detection of JE specic IgM antibody. Among the JE patients, only 4.1% were immunized with SA 14-14-2 vaccine and 14% died before discharge. The complete recoveries were observed in 78% of cases. JE is one of the major causes of AES which is highly prevalent in this part of India. The signicant ndings in the present study calls for policy decision to combat JE.