Use this page to access key information about viral encephalitis.
- Find generic information about the Encephalitis virus, it’s causes and where it’s commonly found.
- Gleam more specific information about Japanese b Encephalitis .Also find information in regards to encephalitis symptoms and warning signs.
- What causes encephalitis? What can be done to prevent it? Find the answers in our full break-down of the illness.
- Click here for information regarding the Japanese B Encephalitis Vaccine
Japanese encephalitis
What is it?
Japanese encephalitis is a viral infection carried by the Culex species of mosquito. It is part of the same virus family as the West Nile Virus.The Encephalitis virus passes from pigs and wading birds to Culex mosquitoes, which live and breed on rice paddies and other flooded areas. Humans can become inadvertent hosts when bitten by the carrier mosquitoes, which are active during the day – something bite avoidance strategies should take into account. Japanese B encephalitis is in decline and rarely affects travellers.
What does it do?
Only around 1 in 300 of those exposed to the virus develops Japanese encephalitis, although the figure is higher in children and the elderly. After between 4 and 14 days, a patient may develop encephalitis symptoms such as a fever, swelling of the brain or paralysis. Around 30% of those who develop the disease will die. For those who survive, while the illness itself typically lasts less than 2 weeks, recovery can take much longer and some people end up with permanent disability.
Where is it ?
Japanese encephalitis has actually been eliminated from Japan but still occurs, particularly following the rains, in Nepal, northern Burma, India, Sri Lanka, Laos, northern Thailand, Vietnam and some areas of China, especially the Yangtse Valley.
Can it be treated?
There is no treatment for viral encephalitis – just good supportive care
Can it be prevented?
Bite prevention measures are the most important means of preventing the disease and should always be used in areas of risk. Travellers who make repeated visits to rural areas or spend longer than a month in them should be immunised. Children and the elderly are at particular risk and should be considered for the vaccine. Similarly, a lower threshold for immunisation should be used during times of increased risk for the disease, such as after the rainy season.
Danger rating: 2/10
