Japanese Encephalitis
September 14, 2023

Understanding and Mitigating the Risks of Japanese Encephalitis

Japanese encephalitis (JE) is an uncommon yet severe infection mainly found in rural regions of Asia, caused by a virus transmitted through mosquito bites. The disease is not endemic in the UK, but travellers visiting areas at risk are encouraged to take preventive measures, including vaccination.

Japanese Encephalitis: An Overview

JE is a mosquito-borne viral infection that, while rare, poses serious health risks. The virus is predominantly found in Asian countries like Japan, South Korea, and parts of Southeast Asia such as Thailand, Malaysia, and Vietnam.

Note: JE is uncommon among travellers, but if contracted, it can be life-threatening.

Areas with JE Risk

The presence of JE is primarily limited to rural regions of Asia, including:

  1. India
  2. China
  3. Japan
  4. South Korea
  5. Indonesia
  6. Southeast Asia (Thailand, Malaysia, Vietnam)

Reducing JE Exposure

Preventing mosquito bites is the primary method of reducing JE risk. If you plan to visit any of the aforementioned regions, consider the following preventive measures:

  • Use insect repellent on exposed skin, preferably containing 50% DEET or higher
  • Sleep under an insecticide-treated mosquito net
  • Wear long-sleeved tops, trousers, long skirts, socks, and shoes to limit skin exposure
  • Seek advice from a travel vaccination clinic before your trip

JE Vaccination

A JE vaccine is recommended for travellers visiting regions where the virus is present, especially if:

  • You plan to stay for more than a month
  • Your visit includes rural areas
  • Your itinerary includes rice fields, wetlands, or pig farms

The JE vaccine is not free and can be obtained from travel health clinics and pharmacies offering travel health services.

Recognizing JE Symptoms

Most individuals infected with JE do not exhibit symptoms. However, some may experience flu-like symptoms, including:

  • Headache
  • Fever
  • Nausea or vomiting
  • Abdominal pain

In some cases, the infection can spread to the brain, causing severe symptoms such as:

  • Intense headache
  • Confusion
  • Paralysis
  • Seizures

Urgent advice: Seek immediate medical attention if you have recently travelled to a region where JE is prevalent and you experience flu-like symptoms. Inform your healthcare provider about your travel history and potential mosquito bites.

Emergency Symptoms

Seek immediate medical help if you or someone else exhibits:

  • Severe headache with a stiff neck
  • Sudden confusion
  • Sudden weakness or paralysis
  • Seizures
  • Loss of consciousness
  • Severe difficulty breathing

Getting Medical Help

If you experience JE symptoms while travelling, seek medical help promptly. Early detection and treatment can significantly improve prognosis.

JE Treatment

JE is a serious condition that requires hospitalization. Treatment mainly involves relieving symptoms through medications like painkillers and steroids.

Long-Term Complications of JE

JE can occasionally cause long-term complications, including paralysis, seizures, and speech loss. Proper medical care and rehabilitation can help manage these complications.

Important: Always seek prompt medical help if you suspect JE. Early treatment can prevent severe complications.


While JE is a rare disease, it is severe and potentially life-threatening. If you are planning a trip to an area at risk, take preventive measures, such as using appropriate insect repellent, wearing protective clothing, and getting vaccinated. If you exhibit symptoms after your trip, seek medical help immediately.

The information in this article is reviewed periodically and last updated on 06 June 2023. The next review is due on 06 June 2026.