[Japanese encephalitis].

Japanese encephalitis is the primary cause of viral encephalitis in Asia where it is annually responsible for the death of around 20,000 people. The virus is transmitted by night-biting mosquitoes in wet rural areas. The classical clinical presentation includes fever, paresis, decreased level of consciousness and convulsions. There is no efficient anti-viral treatment available. Avoidance of mosquito bites and vaccination are the only effective measures to prevent the disease. Vaccination is recommended for travellers and expatriates who will stay in rural endemic areas for at least one month during the rainy season. The vaccine is contra-indicated in individuals with a previous history of severe allergic reaction.