Japanese encephalitis is a viral disease only in East Asia. The infection is spread via a bite from an infected culex mosquito. The culex mosquito favours breeding sites in and around rice paddies and piggeries.
Most cases occur after the monsoon seasons in China, Myanmar, Thailand, Vietnam, Cambodia, Laos, Nepal, India, Philippines, Sri Lanka, Korea, Malaysia, Indonesia and Singapore.
Japanese encephalitis causes headache, convulsions, encephalitis and meningitis. Severe disease can cause permanent neurological damage. About 30% of those with signs of infection will die from the disease.
There is no specific treatment available for Japanese encephalitis.
Recommendations for Travellers
Prevention is focused on avoiding mosquito bites, especially during the hours between dusk and dawn which is when the culex mosquito is most active. Use of insect repellents, appropriate clothing and mosquito nets can be considered.
Currently two vaccines that protect against Japanese encephalitis are available in the UK: IXIARO and Green Cross. 2-3 doses of vaccine need to be given before travel. Individuals should consider being vaccinated if they are travelling to a country where Japanese encephalitis is present and where their stay maybe prolonged or they are involved in travel activities which may increase the risk of exposure to the disease, for example, staying in or around rural areas, jungle trekking.