Japanese encephalitis only occurs in Asia. It is a virus infection which is transmitted by mosquitoes (mainly rice field mosquitoes). The mosquitoes occur mainly in areas where rice is grown (high humidity). They transmit the virus if infected pigs, birds and bats.
Risk areas (Martin Hirte: Impfen:pro&contra, 2001, S. 309-310):
- In summer and fall: North India, Nepal, Bangladesh, Burma, Northern Thailand, Laos, Cambodia, North Vietnam, South Japan, Korea, China and Eastern Siberia
- During monsoon season: Pakistan, South India, South Thailand, South Vietnam, Sri Lanka, Malaysia, Taiwan, Indonesia, Philippines
Generally tourists are not in danger if they remain in areas which are open to tourists. There is, however, a certain amount of risk if you stay in high risk areas (mainly during monsoon season).
For more information please refer to: