Page last updated
16 December 2021
Japanese encephalitis (or JE) is a rare but serious viral infection of the human brain caused by the bite of a particular type of infected mosquito. The disease is rarely found in mainland Australia, however, it is relatively common in many parts of Asia (e.g. Southeast Asia, India, China).
In the vast majority of cases (about 99%), people will experience very mild or no symptoms from an infection. In a small number of cases, infection may lead to swelling of the brain (encephalitis) and its associated symptoms, including headache, high fever, disorientation, coma, tremors and convulsions. In people who do develop the disease, 10-30% will die and 50% will have a permanent disability.