Japanese Encephalitis Virus

Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that causes Japanese encephalitis (JE), a severe neurological disease. The primary vector for JEV transmission is the Culex mosquito, particularly Culex tritaeniorhynchus. The virus primarily circulates in an enzootic cycle involving pigs and wading birds, with humans serving as incidental hosts. The virus is prevalent in certain regions of Asia, including parts of Southeast Asia, the Indian subcontinent, and the Far East. JEV transmission occurs in rural and peri-urban areas, where rice fields and pig farming provide suitable breeding grounds for mosquitoes. The virus is maintained in a complex cycle involving amplification in pigs and transmission to humans through mosquito bites. In endemic areas, JE outbreaks often coincide with the monsoon season when mosquito populations peak. Clinical manifestations of Japanese encephalitis range from mild febrile illness to severe encephalitis with neurological complications. The disease has a significant impact on pediatric populations, and survivors may experience long-term neurological sequelae. Preventive measures for Japanese encephalitis include vaccination, vector control, and health education. Vaccination campaigns target high-risk populations, such as children in endemic areas, and have contributed to a reduction in JE cases in some regions.