Japanese Encephalitis

Japanese Encephalitis

Japanese Encephalitis is deadly a virus that can cause inflammation of the brain. Most cases occur in Asia – it is not found in Africa or Central or South America. Even though the occurrence of Japanese Encephalitis is rare, the serious form has a fatality rate of 30%. There is a major outbreak of Japanese Encephalitis every 2-15 years. The virus begins with a mosquito biting an infected pig or bird, then going on to bite a human, transmitting the disease.

The main symptoms include:

  • A high temperature
  • Seizures
  • A stiff neck
  • Confusion
  • The inability to speak
  • Uncontrollable shaking of body parts (tremor)
  • Muscle weakness or paralysis

Up to 1 in every 3 people who develop these more serious symptoms will die as a result of the infection. In those who survive, these symptoms tend to slowly improve. But it can take several months to make a full recovery, and up to half of those who do survive are left with permanent brain damage. This can lead to long-term problems, such as tremors and muscle twitches, personality changes, muscle
weakness, learning difficulties and paralysis in 1 or more limbs.

1. How do you catch it?

When an infected mosquito bites a human, the disease can be transmitted from the mosquito to the human. These mosquitoes mainly bite during the night. Japanese Encephalitis mainly occurs in rural agricultural areas.

2. Prevention?

Protect yourself from mosquito bites! This can be achieved through use of an effective insect repellent as well as wearing long, loose-fitting clothing. Stick to long sleeved shirts and pants during peak hours. More importantly, a vaccine is also available to help prevent a mosquito bite from infecting you.

3. Vaccination options

Vaccination should be considered by those intending to spend a significant length of time in rural areas.

Number of doses? 2 doses
When to do the course? Considering the 2nd dose is administered 28 days after the 1st dose, you should start the course 4-6 weeks before your planned travel date. An accelerated schedule is also available for last minute travellers!
Booster doses? You should consider a booster 12-24 months after the first course, especially if you are planning to travel to destinations with a risk for Japanese Encephalitis.
Age restrictions? Vaccine is available for anyone above the age of one.

4. At Risk Destinations

Japanese Encephalitis is found throughout Asia and beyond.

Most cases occur in:

  • China
  • Myanmar (Burma)
  • Thailand
  • Vietnam
  • Cambodia
  • Laos
  • Nepal
  • India
  • Philippines
  • Sri Lanka
  • Malaysia
  • Indonesia

Despite its name, Japanese Encephalitis is now relatively rare in Japan as a result of mass immunisation programmes.


For a free risk assessment and expert advice, contact us today and speak with one of our dedicated healthcare professionals.