Risk factors for and spatio-temporal distribution of acute encephalitis syndrome in Nepal (360G-Wellcome-102465_Z_13_A)

Acute Encephalitis Syndrome (AES) causes high rates of morbidity and mortality in Nepal, particularly in children. Despite the introduction of a vaccine against Japanese encephalitis virus (JEV) (a major cause of AES), numbers remain high, and there are many cases of AES where the cause is unknown. The majority of these are in the low-altitude, densely irrigated, southern Terai region and coincide with the wet season. This suggests that many cases may be due to vector-borne pathogens. The primary goal of the study is a) to identify the environmental, socio-demographic and behavioural risk factors associated with known and unknown causes of AES using a case-control study and b) to assess the extent to which these factors explain the observed spatio-temporal distribution of AES. This will improve knowledge of the epidemiology of AES, provide guidance towards the cause, and help disease control methods. Secondary goals are: 1. To estimate and map the residual, unexplained spatio-temporal variation of AES and to produce a model which aims to estimate the population-based risk of AES. 2. To analyse the contact patterns and daily activities of healthy participants living in districts of high AES incidence, and produce models of exposure to risk factors associated with vector-borne diseases. This will be an exploratory aim.