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Japanese Encephalitis

Japanese encephalitis is a potentially fatal viral disease spread by the bites of infected mosquitoes found in South East Asia, the Pacific islands and the Far East, particularly in the rainy season (roughly May-September) when the mosquitoes are most active. The people most at risk of infection are those who live and work in rural farming areas where the condition is endemic. It does not usually occur in urban areas and it cannot be spread from person to person.

The Japanese encephalitis virus mostly causes flu-like symptoms such a fever, tiredness, headache, vomiting, and sometimes confusion and agitation. However, in a small number of cases the infection can spread to the brain (causing encephalitis) and become life threatening. This results in symptoms including sudden onset of headache, high fever, disorientation, coma, tremors and convulsions, particularly in children, resulting in permanent brain damage, coma and in some instances death.

The prognosis is variable but about 1 in 4 cases are fatal and in endemic regions it generally occurs among children [6]. Death usually occurs in the first five days with deepening coma and respiratory arrest. Many of those who survive are left with permanent brain damage while 30%-50% of survivors continue to have lifelong neurological, cognitive, or psychiatric symptoms [8,12].

There is currently no cure or specific treatment for Japanese encephalitis and supportive care and hospitalisation is required to help manage the symptoms.

Recommendations for travellers
Travellers, particularly when visiting paddy fields and other rural areas, should seek to avoid mosquito bites, especially during the hours between dusk and dawn which is when this mosquito is most active. Use of insect repellents, appropriate clothing and mosquito nets should be used where possible.

Vaccines are available in the UK for individuals aged two months and older. Vaccination is recommended before travelling to a high risk area particularly where your stay may be prolonged or there is an increased risk of exposure to the disease e.g. staying in or around rice growing areas or during monsoon.

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Japanese Encephalitis Vaccination Here’s the point

A British woman who had been living and working in Hong Kong was diagnosed with JE in 1982 and died as a result of cardiac and respiratory complications. A man, who had been to Thailand for a martial art competition in Jan 2013 and who had spent only a few days in an area where he could have been exposed to the virus, made a recovery after 4 months.[13]