Japanese encephalitis is an infection caused by a virus that is spread to humans through the bite of an infected mosquito.
For most travellers to Asia, the risk for infection is very low, but varies based on the destination, the length of travel, the season and the types of activities they will be doing. Travellers staying in rural villages, especially if it is for a long period of time (over a month) and those who will be doing outdoor activities (hiking, camping) are at higher risk of getting infected.
Very few people develop symptoms of illness. For those that do have symptoms they may include:
- sudden fever
- headache
- vomiting
- neck stiffness
- confusion
- generally feeling unwell
- being paralysed
- coma
- seizures
It usually takes 5 to 15 days for a person to show symptoms after being exposed to the infection.
You should see a health care provider if the illness seems to be causing any of the more serious symptoms.
Japanese encephalitis is spread through the bite of an infected mosquito. Mosquitos that carry this disease usually bite from sunset to sunrise.
There is no specific treatment for Japanese encephalitis, but hospitalization for supportive care and close observation are generally required for people who become ill.
- Protect yourself from mosquito bites by using appropriate insect repellent, using bed nets and by following other mosquito prevention tips. Learn more about insect bite prevention.
- There is a vaccine available to protect against Japanese encephalitis. Talk to your health care provider about getting vaccinated.
- Monitor your health if you are travelling.