Murray Valley Encephalitis

Following an increase in occurrences of Japanese encephalitis virus (JEV), Murray Valley encephalitis (MVE) has been detected in northern Victoria this mosquito season, the first detection of the virus in Victoria in over 10 years.

MVE is spread to humans via infected mosquitos and can cause potentially serious illness.  It is not transmitted from person to person.


Most MVE infections are asymptomatic, however approximately one percent of those infected can develop clinical disease.   Symptoms include fever, headache, nausea, vomiting and muscle aches. In rare cases, people can develop meningitis or encephalitis and have symptoms of severe headache, neck stiffness, sensitivity to bright lights, drowsiness, confusion, seizures, loss of consciousness or coma. Symptoms usually start 7-12 days after being bitten by an infected mosquito but may occur anywhere from 5 to 28 days after exposure.

The risk of mosquito-borne diseases, such as MVE, JEV, Kunjin/West Nile virus, and Ross River and Barmah Forest virus infections, is high due to recent weather conditions and elevated mosquito numbers across Victoria.

People with increased exposure to mosquitoes may be at a higher risk of infection.  These include people who work, live or spend time outdoors in rural or regional Victoria, particularly inland riverine regions and extending up towards the Murray River.


People with increased exposure to mosquitoes may be at a higher risk of infection, particularly when camping, or working or spending time outdoors in northern and north-western Victoria and the Murray River regions.

Steps to protect yourself against mosquito-borne diseases include:

  • Wearing long, loose-fitting clothes while outdoors.
  • Using mosquito repellents containing picaridin or DEET on all exposed skin.
  • Prompt washing and covering of cuts and scratches caused with outdoor activities.
  • Limiting outdoor activity if lots of mosquitoes are about.
  • Using ‘knockdown’ fly sprays and plug-in repellent devices indoors.
  • Using mosquito coils in small outdoor areas where you gather to sit or eat.
  • Making sure your accommodation is mosquito-proof.
  • Sleeping under mosquito nets treated with insecticides if you don’t have fly wire screens on windows on your home or are sleeping in an untreated tent or out in the open.
  • Prevent mosquitos breeding around your home by removing sources of stagnant water.

Visit Beat the Bite! on Better Health Channel for more information.

Further information

You can find further information at the following websites: