Japanese Encephalitis

Japanese encephalitis (JE) is a viral illness transmitted by mosquitoes, primarily Culex species. It typically occurs in areas where rice growing and pig farming occur together, namely most of Asia, part of Papua New Guinea and the Torres Strait.


It usually takes from four to 14 days for symptoms such as fever, muscle aches, and severe headache to develop. In some people, symptoms may progress to include stiffness of the neck and eventually coma, which can result in death or irreparable brain damage.

For travellers there is a very low risk of being infected but the consequences of the disease can be high. Japanese encephalitis can result in death and brain damage in a significant proportion of those developing the disease.


The first line of defence against Japanese encephalitis is avoiding mosquito bites. Two new vaccines are available and both are very effective in prevention. One vaccine is a ‘live’ single-dose formula which protects individuals for several years. The second vaccine involves a course of two injections over a month, then a booster every two to three years if risk is on- going. Both Japanese encephalitis vaccines are suitable for children as young as 12 months.