The  japanese encephalitis is caused by a Flavivirus.

The disease spreads to humans when they are bitten by an infected mosquito.Japanese encephalitis is found in almost all Asian countries and parts of the western Pacific. It is mainly a threat in rural agricultural areas where there is widespread irrigation (artificial watering of crops). This includes areas with rice fields.

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

Source: Health Canada