Viral brain infection that spreads through mosquito bites.


  • Appear 5 to 15 days after being infected
  • Mental status changes, neurologic symptoms, weakness
  • Seizures, movement disorders
  • High temperature (fever)
  • Stiff neck
  • Confusions, severe headache and laziness
  • Drowsiness, dilated pupils
  • Mental retardation
  • Issues like seizures, disorientation
  • tremors and hallucinations.
  • Less hunger, hyper sensitivity, stupor
  • Muscle weakness or paralysis
  • Coma


  • Caused by Japanese encephalitis virus
  • Virus originates from mosquitoes and swines
  • Infected mosquitoes-Culex species
  • Aedes mosquitoes are also being implicated
  • Non communicable

Risk factors:

  • High-risk countries – Asia and beyond.
  • Rainy seasons-highest risk of being infected
  • People living in agricultural and rural areas (mosquito spread)
  • Infection in a pregnant woman can harm unborn baby
  • Living or travelling in high-risk areas for a long time
  • Fieldwork, camping or cycling in rural areas


Diagnostic tests:

  • Laboratory testing
  • Computed tomography (CT) scan
  • Magnetic resonance image (MRI) of the brain.
  • Lumbar puncture or spinal tap
  • Immunofluorescence tests

Differential diagnostics:

  • Fever accompanied with headache
  • Encephalitis (brain infection)
  • Arboviral diseases (West Nile virus, Murray Valley encephalitis)
  • Nipah virus infection
  • California encephalitis
  • Enterovirus infection
  • Herpes simplex
  • Dengue fever
  • Bacterial infections like Pyogenic focal brain abscess
  • Tuberculosus & Mycoplasma meningitis
  • Typhoid fever


  • Treatment is symptomatic
  • Japanese encephalitis vaccine
  • Rest, fluids, and use of pain relievers
  • Supportive care


  • To reduce fever
  • Relieving symptoms
  • Mannitol- to decrease intracranial pressure
  • Steroids (eg, dexamethasone)
  • Anticonvulsants for seizure control
  • Experimental therapies:
  • Suramin- showed good antiviral efficacy
  • Arctigenin (plant lignan)- successfully tested in mouse model
  • Minocycline-protection against encephalitis and neurodegeneration

Lifestyle Management:

  • Protective clothing, bed nets, and repellents
  • Timely vaccination
  • Maintaining cleanliness
  • Proper sanitation, Avoiding going in dirty water
  • Avoiding water accumulation
  • Taking Special care during monsoon season
  • Taking Hygienic food
  • Using Close-fitting gauze over the windows and doors