Japanese encephalitis (JE) is a viral infection caused by the Japanese encephalitis virus (JEV), which is a flavivirus transmitted primarily by mosquitoes, especially Culex species. Here are key aspects of Japanese encephalitis:

1. Transmission: Japanese encephalitis virus is primarily transmitted through the bite of infected mosquitoes, particularly in rural agricultural areas where mosquitoes breed in rice paddies and other water bodies. Certain species of pigs and wading birds can act as amplifying hosts, contributing to the virus’s transmission cycle.
2. Geographical Distribution: Japanese encephalitis is endemic in parts of Asia and the western Pacific. It is particularly prevalent in rural areas of Southeast Asia, East Asia (including Japan and Korea), and the Indian subcontinent.
3. Symptoms: Most infections with Japanese encephalitis are asymptomatic or result in mild symptoms similar to flu. However, in severe cases, the virus can cause inflammation of the brain (encephalitis), leading to symptoms such as high fever, headache, neck stiffness, disorientation, coma, seizures, and paralysis.