Traveller vaccination japanese encephalitis

Template:Traveller vaccination japanese encephalitis virus Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Seyedmahdi Pahlavani, M.D. [2]

Disease cause

Japanese encephalitis virus

Transmission

Pigs and various wild birds represent the natural reservoir of this virus, which is transmitted to new animal hosts and occasionally human beings by mosquitoes of the genus Culex.
Culex mosquitoes are primarily day-biting.

Nature of the disease

Mostly asymptomatic. Symptoms could be vary from mild infections that are characterized by febrile headache or aseptic meningitis followed by an uneventful recovery; severe cases have a rapid onset and progression with headache, high fever and meningeal signs.

Geographical distribution

Japanese encephalitis virus is the leading cause of viral encephalitis in Asia and occurs in almost all Asian countries. Transmission occurs mainly during the rainy season in south-east Asia but may take place all year round, particularly in tropical climate zones.

Risk for travellers

The risk of japanese encephalitis is very low for most travellers to Asia, particularly for short-term visitors to urban areas. However, the risk varies according to season, destination, duration of travel and activities.

• Vaccination is recommended for travellers with extensive outdoor exposure (such as camping, hiking and working) during the transmission season, particularly in endemic countries or areas where farming involves flooding irrigation.
• Prevention is by avoidance of mosquito bites and by vaccination.

Vaccine

Inactivated Vero cell-derived, live attenuated and live recombinant vaccines are available. Vaccination against japanese encephalitis is recommended for travellers to endemic areas who will have extensive outdoor exposure during the transmission season.