Symptoms of Japanese encephalitis

Learn about the symptoms of Japanese encephalitis, what to look for and what to do if you become ill.

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What are the symptoms of Japanese encephalitis?

Symptoms can take between 5 and 15 days to appear. It is common for most people to show no symptoms.

Less than 1% of infected people develop encephalitis (brain swelling), which is fatal in about 20% to 30% of these cases.

In severe cases, symptoms usually appear suddenly, starting with:

  • fever
  • vomiting
  • headaches

Symptoms may also include:

  • coma
  • seizures
  • stiff neck
  • confusion
  • general weakness
  • movement disorders
  • mental or behaviour changes
  • paralysis (being unable to move)
  • possible long-term nerve and brain damage

What do you do if you become ill?

Consult a health care provider if you have:

  • travelled to an area where Japanese encephalitis is present
  • any of the listed symptoms

Tell your health care provider:

  • your symptoms
  • which countries you visited or lived in

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