Home/Diseases/Japanese Encephalitis

Japanese Encephalitis

Severity: Moderate

Japanese encephalitis is rare in travelers but potentially devastating — about 30% of symptomatic cases are fatal, and up to 50% of survivors have permanent neurological damage. The vast majority of infections (99%) are asymptomatic or cause only mild illness.

The virus is transmitted by Culex tritaeniorhynchus mosquitoes, which breed in rice paddies and bite at dusk. Risk is concentrated in rural agricultural areas of East and Southeast Asia, particularly during and after monsoon season when rice cultivation and mosquito populations peak.

A safe and effective vaccine is available and recommended for travelers spending more than one month in rural endemic areas. Short-stay urban visitors are at very low risk.

Pathogen

Virus

Culex tritaeniorhynchus — a night-biting species closely associated with rice cultivation and pig farming.

Risk Groups

Who is at risk
Moderate

Long-stay travelers in rural Southeast and East Asia during monsoon season. Children under 15 and adults over 65 are more vulnerable. A vaccine is available and recommended for extended trips.

Symptoms

Most infections are asymptomaticFever, headache, vomitingAltered mental state and confusionSeizures, especially in childrenNeck stiffness and paralysis in severe casesUp to 30% fatality in symptomatic encephalitis

Mosquito species that transmit Japanese Encephalitis

Culex quinquefasciatus

Precautions

Get vaccinated if traveling to rural Asia for more than 1 month
Use repellent at dusk and after dark
Avoid rice paddy and pig farm areas where possible
Sleep under treated bed nets in rural accommodation
Vaccination course requires 2 doses over 28 days — plan ahead
Short urban visits carry very low risk
WHO Japanese EncephalitisCDC JE Vaccine Info

Countries with Japanese Encephalitis

Japanese Encephalitis is recorded in 21 countries in our database. Click any country for the full Mozzwise briefing covering local seasonality, regional risk, and prevention.

AustraliaBangladeshCambodiaChinaIndiaIndonesiaJapanLaosMalaysiaMyanmarNepalNorth KoreaPakistanPapua New GuineaPhilippinesSouth KoreaSri LankaTaiwanThailandTimor-LesteVietnam

Disease information is sourced from WHO, CDC, ECDC, and OpenDengue. Not medical advice. Personal decisions on diagnosis, treatment, vaccinations, or medication belong with a qualified healthcare professional.

Japanese Encephalitis — Mosquito-Borne Disease | Mozzwise