Japanese Encephalitis

Japanese Encephalitis (JE) is a potentially serious viral infection caused by the bite of an infected Culex mosquito.

What are the symptoms of Japanese Encephalitis?

Many people with JE illness may experience only mild symptoms such as fever and headache. Some people will not experience any symptoms. However, one out of every 200 people with JE infection will develop a potentially fatal brain inflammation, which is characterized by rapid onset of high fever, headache, neck stiffness, disorientation, coma, seizures, and spastic paralysis. The death rate can be as high as 60 percent among those with symptoms. Up to one-third of survivors will have long-term brain or nerve damage.

How can I get Japanese Encephalitis?

You can get JE if a Culex mosquito the virus bites you after becoming infected by biting an infected animal such as a pig or a wading bird. Culex mosquitoes are active throughout the night and are most likely to bite in the hours just after dusk and just before dawn.

Where can I get Japanese Encephalitis?

Japanese Encephalitis occurs in most Asian countries and some parts of eastern Russia. The risk is low for travellers to urban areas, but it increases for those who travel or live for a month or more in agricultural areas, particularly where rice is grown or irrigation is widespread.

In temperate regions such as China, Japan, and Korea, transmission is sporadic and seasonal, usually from July to September. However, transmission can occur year round in sub-tropical areas such as Thailand, Vietnam, Cambodia, Malaysia, and Singapore.

What vaccines are available for Japanese Encephalitis?

The risk for JE during travel to urban areas that last for less than one month is lower than 0.0001 percent. The decision to vaccinate depends on many factors such as the length of stay, the time spent in agricultural areas, and the time of year. However, because JE can be very serious, it is advisable to consider vaccination after you have discussed your itinerary with your travel health specialist.

The JE vaccine available in Canada, Ixiaro™, is licensed only for adults. It is a well-tolerated and effective vaccine. If you will be travelling with children, please discuss your potential options with your travel health specialist.

For more info on Japanese encephalitis and Ixiaro™ – click here

How many shots will I need?

The vaccine is given in two doses, spaced 28 days apart. If possible, you should get the second dose at least one week before you leave on your travels.

Will I need a booster?

The vaccine provides protection for up to two years. If you remain at continuous risk of exposure (e.g. living in an endemic area) following your first immunization, you should get a booster dose 12 months after your first immunization. If you are returning to a JE endemic area, you should get a third dose within 12–24 months after your first immunization.

How can I prevent Japanese Encephalitis?

In addition to being vaccinated for JE, avoid mosquito bites by using insecticide aerosol sprays and insect repellents containing DEET or Icardin and taking other preventive measures such as limiting your outdoor activities at night, wearing permethrin-treated clothing, and sleeping in screened or air-conditioned areas or under permethrin-treated mosquito nets.

Use additional protective measures for children and infants such as self-standing mosquito nets that can be placed over a car seat, crib, playpen, or stroller.

What is the treatment for Japanese Encephalitis?

There is no specific treatment for JE.


Find out more information on viruses from our Vancouver Travel Clinic or any of our other 18 Travel Clinic locations.