An Overview of Japanese Encephalitis

INTRODUCTIONJapanese encephalitis virus (JEV) is a flavivirus, is the main cause viral encephalitis, endemic in South-East Asia, and Western Pacific regions and has become a major public health problem worldwide. JEV is transmitted to humans through the bite of an infected mosquito, mainly Culex tritaeniorhynchus that breeds in flooded rice fields, marshes, standing water around planted fields. Reservoir hosts are Adreid birds (herons and egrets), and pigs serve as amplifier hosts. Though infections are usually asymptomatic, the symptomatic Japanese encephalitis has a case fatality rate as high as 30%. Permanent neurologic or psychiatric sequelae can occur in 30-50% of those with encephalitis. There is no antiviral drug available. Treatment is mainly supportive and symptomatic. Safe and effective vaccines are available to prevent Japanese encephalitis. This article reviews recent advancements in diagnostic methods, prophylactics as well as therapeutic options and challenges to combat this zoonotic emerging and remerging viral encephalitis.