Japanese encephalitis is a viral disease spread by culex mosquitoes. The virus can cause encephalitis, an inflammation of the brain which can be fatal. The culex mosquito favours breeding sites in and around rice paddies, swamps and marshes and feeds mostly around dusk and dawn. Domestic pigs and large birds act as a viral reservoir allowing transmission to humans. The virus is found in most countries in Asia and although variable, cases often peak annually during and after the monsoon seasons with sporadic cases occurring at other times.
Most individuals infected with JE will not go on to develop disease, of those that do develop encephalitis there is significant risk of mortality (up to 30%) or severe neurological damage on recovery. There is no specific treatment available.
Recommendations for Travellers
Prevention is focused on avoiding mosquito bites, especially during the hours around dusk and dawn when mosquitoes are most active. Use of insect repellents, appropriate clothing, mosquito nets and other bite avoidance measures should be used.
Ixiaro vaccine can be given from age 2 months, 2 doses are required given a minimum of 4 weeks apart: this interval may be reduced in exceptional; circumstances, for example, when time to departure is limited. The need for vaccination should be particularly considered in travellers to a country where Japanese encephalitis is present and where their stay may be 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. As with all vaccines the clinical staff will advise during the travel consultation on all aspects of the procedure including vaccine dose schedule, contraindications to vaccination, any possible interactions with other vaccines or medications, the range of possible adverse effects from the specific vaccine and any queries. Written product information to retain for reference is also provided.
More information: -http://www.nathnac.org/travel/factsheets/japanese_enc.htm