Japanese Encephalitis

What is Japanese encephalitis?

Japanese encephalitis (JE) is a disease spread through mosquito bites. Symptoms usually take 5-15 days to develop and include fever, headache, vomiting, confusion, and difficulty moving. Symptoms that develop later include swelling around the brain and coma. JE is a serious disease that may cause death.

Who is at risk?

Travelers who go to certain parts of Asia are at risk for getting Japanese encephalitis. For most travelers the risk is extremely low but depends on where you are going, the time of year, your planned activities, and the length of the trip. You are at higher risk if you are traveling to rural areas, will be outside frequently, or will be traveling for a long period of time. In mild climates in northern Asia, the risk for JE is greater in the summer and fall. In tropical and subtropical areas, there is a risk year-round.

What can travelers do to prevent Japanese encephalitis?

Travelers can protect themselves from JE by getting the JE vaccine and preventing mosquito bites.

Get the JE vaccine

  • Talk to your provider about your travel plans. Your travel medicine provider can help you decide if you need the JE vaccine based on the length of your trip, the areas where you will be traveling, and your planned activities.
  • See your travel medicine provider at least 6 weeks before your trip:
    • The JE vaccine is given in 2 doses that are spaced over a month.
    • You should get the last dose at least 10 days before your trip.

Prevent mosquito bites

Use insect repellent, cover exposed skin, and avoid mosquitoes where you are staying. For more information, see Mosquito Safety/Vector Avoidance.

Page reviewed on: Mar 09, 2017

Page reviewed by: Jessie L. Leyse, MD