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What is Japanese encephalitis?

Page last updated 03 April 2020


Japanese encephalitis (or JE) is a rare but serious viral infection of the human brain caused by the bite of a particular type of 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 (approaching 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.


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Sources & Citations

1. Australian Government, Department of Health. The Australian Immunisation Handbook. Japanese encephalitis. Available at: (accessed 10 March 2020).

2. NSW Government, Department of Health. Japanese encephalitis fact sheet. Available at; (accessed 10 March 2020).

7. Centers for Disease Control and Prevention. Japanese encephalitis – symptoms & treatment. Available at: (accessed 10 March 2020).

SPANZ.IMOJ.18.04.0141(1)a - Date of preparation March 2020