Japanese encephalitis virus (JEV) Vaccination

What is Japanese encephalitis?

Japanese encephalitis is a rare but potentially serious infection of the brain caused by the Japanese encephalitis virus (JEV). It can be spread to humans through mosquito bites.

JE virus was detected in Victoria for the first time in February 2022 in pigs, humans, and mosquitoes. Human cases have been reported in Victoria, New South Wales, and South Australia.

Who is at risk?

Anyone is potentially at risk of being bitten by mosquitoes. An infected mosquito can potentially transmit JEV and other mosquito-borne infections.

Residents and people visiting northern Victoria, particularly inland riverine regions and near the Murray River, are at higher risk of infection and are strongly advised to take measures to protect against mosquito bites.

People who live or work at properties with pigs may also be at higher risk.

What are the symptoms?

Most people infected with JEV do not have symptoms or have only mild symptoms. However, a small percentage of infected people develop inflammation of the brain (encephalitis).

Illness usually begins with:

  • fever
  • headache
  • nausea
  • vomiting
  • myalgia

People with severe illness can develop encephalitis or meningoencephalitis and have symptoms such as:

  • drowsiness, confusion or other mental status changes
  • meningism with severe headache, neck stiffness and photophobia
  • cranial nerve pathology
  • generalised weakness or paresis (muscle weakness)
  • movement disorders such as ataxia and Parkinsonism
  • seizures, which are more common in children
  • loss of consciousness and coma.

How to protect yourself and others?

The most effective way to prevent JEV and other mosquito-borne infections is by avoiding mosquito bites and removing mosquito breeding sites from around your home and property.

You can find ways to protect yourself from mosquito-borne infections here

Where to get vaccinated?

Please refer to the following website for up-to-date information on vaccination and eligibility criteria here

More information

Website: Victorian Department of Health - Japanese Encephalitis