What is Japanese Encephalitis?
Japanese encephalitis is a disease spread to humans by the bite of an infected mosquito. It is caused by a flavivirus similar to West Nile Virus. It can cause swelling of the brain, and possible long-term nerve and brain damage.
Japanese encephalitis can be prevented with a vaccine.
What is my risk?
The risk to most travellers is low, particularly for those staying in urban areas.
Travellers to countries where Japanese encephalitis occurs are at greater risk if:
visiting rural and agriculture areas, particularly if the stay is over an extended period of time (one month or more).
participating in outdoor activities such as camping, hiking, cycling or fieldwork.
How is it transmitted?
Japanese encephalitis is spread through the bite of an infected Culex mosquito. Mosquitoes that carry Japanese encephalitis bite mainly from sunset to sunrise.
What are the symptoms?
Symptoms can take between 5 to 15 days to appear. It is common for most people to show no symptoms.
In more severe cases, they:
usually include sudden onset of fever, headaches, and vomiting.
can also include neck stiffness, confusion, mental or behavioural changes, generalized weakness, paralysis,
coma, seizures, or convulsions.
The disease is fatal in about 20-30% of severe cases who develop encephalitis.
There is no specific treatment for Japanese encephalitis but medical care can help with recovery and the control of symptoms.
Where is Japanese-Encephalitis a concern?
Japanese encephalitis occurs in almost all Asian countries and parts of the western Pacific.
In tropical and subtropical areas of Southeast Asia (for example, Indonesia, Malaysia, Singapore, Thailand, Vietnam), transmission can occur year-round.
Source: © All Rights Reserved. Travel Health: Japanese Encephalitis. Public Health Agency of Canada, 2014. Reproduced with permission from the Minister of Health, 2014