Seasonality by Country22†‡§
Country | Affected areas | Transmission season |
---|
Australia | Outer Torres Strait Islands, parts of four states on mainland (New South Wales, Queensland, South Australia, Victoria) | December–May |
Bangladesh | Widespread | Year-round with most cases reported July–November |
Bhutan | Presumed widespread in nonmountainous areas | Unknown |
Brunei Darussalam | Presumed widespread | Unknown |
Burma (Myanmar) | Widespread | Year-round with most cases reported May–September |
Cambodia | Widespread | Year-round; peak season May–October |
China | All provinces except Xinjiang and Qinghai | Peak season June–October |
India | Andhra Pradesh, Arunachal Pradesh, Assam, Bihar, Goa, Haryana, Jharkhand, Karnataka, Kerala, Maharashtra, Manipur, Meghalaya, Nagaland, Odisha, Punjab, Tamil Nadu, Telangana, Tripura, Uttar Pradesh, Uttarakhand, West Bengal | Peak season May–November, especially in northern India; the season may be extended or yearround in some areas, especially in southern India |
Indonesia | Widespread | Year-round, with peak season varying by island |
Japan | All islands | June–October |
Lao People’s Democratic Republic | Widespread | Year-round; peak season June–September |
Malaysia | Widespread | Year-round, with peak season in Sarawak from October–December |
Nepal | Southern lowlands (Terai), some hill and mountain districts | Peak season June–October |
North Korea | Presumed widespread | Unknown Proximity to South Korea suggests peak transmission May–November |
Pakistan | Unknown | Unknown |
Papua New Guinea | Widespread | Presumed year-round |
Philippines | Widespread | Year-round; peak season April–August |
Russia | Primorsky Krai | June–September |
Singapore | Presumed in focal areas | Year-round |
Sri Lanka | Widespread except in mountainous areas | Year-round with peak season November–February |
Taiwan | Widespread | Peak season May–October |
Thailand | Widespread | Year-round with peak season May–October, especially in northern Thailand Highest rates of disease reported from Chiang Mai Valley Several traveler cases reported in recent years from resort and coastal areas of southern Thailand |
Timor-Leste | Presumed widespread | No data Proximity to West Timor suggests year-round |
Viet Nam | Widespread | Year-round with peak season May–October, especially in northern Viet Nam |
† Destination and transmissions season information should be considered in association with travel duration and activities when making decisions on vaccination.22 |
‡ Data are based on published and unpublished reports. Risk assessments should be performed cautiously, because risk can vary within areas and from year to year, and surveillance data regarding human cases and JE virus transmission are often incomplete. In some endemic areas, human cases among residents are limited because of vaccination or natural immunity among older people. However, because JE virus is maintained in an enzootic cycle between animals and mosquitoes, susceptible visitors to these areas still may be at risk for infection.22 |
§ Outbreaks previously occurred in the Western Pacific Islands of Guam (1947–1948) and Saipan (1990), but as they are no longer considered risk areas, they are not included in the table.22 |