Japanese Encephalitis

A mosquito-borne viral infection of the brain. Most infections are mild, but severe cases can be fatal or cause lasting brain damage.

InfectionBrainMosquito-borneLast updated: 21 October 2026

Quick Summary

Primary Symptoms

Fever, headache, vomiting, confusion, fits and drowsiness in severe cases.

Common Treatments

Supportive hospital care; no specific antiviral. Vaccination prevents it.

Risk Factors

Living in rural areas with rice fields and pig farming, especially children, during the monsoon.

OverviewSymptomsCausesTreatmentFAQ

Overview

Japanese encephalitis is spread by Culex mosquitoes. Outbreaks occur in parts of India, especially among children.

The JE vaccine is part of India's immunisation programme in affected districts.

Symptoms

Fever

Sudden onset.

Headache and vomiting

Early symptoms.

Confusion

Altered behaviour.

Fits or coma

Emergency care needed.

Causes & Risk Factors

Biological Causes

Infection with the JE virus from mosquito bites.

Key Risk Factors

  • Location Endemic rural districts.
  • Age Children.
  • Not vaccinated Main preventable risk.

Management & Treatment

01. Hospital care

Supportive treatment.

02. Rehabilitation

For survivors.

03. Prevention

Vaccination and mosquito control.

Frequently Asked Questions

Is there a cure?
No specific treatment; prevention is key.
Is the vaccine available?
Yes, in endemic areas.

Sources and further reading

Last updated 21 October 2026. For more detail, see these trusted health organisations.