• Barmah Forest virus is spread by mosquito bites.
  • Joint inflammation and pain, fatigue and a rash are the usual symptoms of Barmah Forest virus disease.
  • Reduce the chance of being bitten by mosquitoes by wearing long, loose-fitting, light coloured clothing and use effective insect repellent in mosquito-prone areas.

About Barmah Forest virus disease

Barmah Forest virus disease can cause joint inflammation and pain, fatigue and a rash of variable appearance. A full recovery can be expected. Most people recover completely within 6 months, although some people have intermittent symptoms for longer.

Barmah Forest virus disease is caused by an alphavirus, which is spread by mosquitoes. Symptoms usually begin to appear between 7 to 10 (but up to 21) days after becoming infected, however many people infected with Barmah Forest virus will never develop any symptoms.

When in mosquito-prone areas, wear long, loose-fitting, light coloured clothing and use insect repellent containing DEET or Picaridin to help reduce the chance of being bitten by mosquitoes.

Symptoms of Barmah Forest virus disease

The symptoms of Barmah Forest virus disease are similar to Ross River virus disease, another mosquito-borne illness, however they tend to be milder.

Symptoms include:

  • lethargy or fatigue
  • joint pain – may affect wrists, knees, ankles or small joints of the extremities, such as fingers or toes
  • rash of variable appearance on the trunk and limbs
  • muscle aches and pains
  • fever.

Mosquitoes spread Barmah Forest virus

People can be infected with Barmah Forest virus when they are bitten by a mosquito carrying the virus. While not proven, it is thought that mosquitoes pick up the virus from kangaroos, cattle and other animals that can act as a natural host for the virus. Diseases that are spread by insects are known as ‘vector-borne’ diseases.
There is no evidence that Barmah Forest virus can be spread directly from one person to another.

Barmah Forest virus disease occurs occasionally in Victoria

Barmah Forest virus disease occurs throughout most regions of Australia including regional Victoria, particularly around inland waterways and coastal regions. However it’s relatively rare in Victoria. There were less than 20 cases reported in Victoria each year between 2015 and 2019.
Epidemics occur from time to time and are related to environmental conditions that encourage mosquito breeding, such as heavy rainfall, floods, high tides and high temperatures.

Blood tests will show if you have Barmah Forest virus

Blood tests can reveal if a person has been infected with Barmah Forest virus recently or in the past. If there has been an outbreak in your local area, the disease may be diagnosed by your doctor based solely on symptoms. However, blood tests are recommended to confirm the diagnosis.

Most people recover from Barmah Forest virus disease

The majority of people with Barmah Forest virus disease recover completely within 6 months. Current knowledge suggests that the body builds an immune response to the virus, which is likely to protect you against the disease for the rest of your life.

Some people may have symptoms that last longer than 6 months or recur, but these may be due to other causes. See your doctor to check your diagnosis if you are concerned about ongoing symptoms.

Preventing Barmah Forest virus disease

There is no preventive vaccine available. Your only protection against Barmah Forest virus is to avoid mosquito bites.

To reduce the risk of infection:

  • Wear long, loose-fitting, light-coloured clothing and use insect repellents that contain DEET or Picaridin applied regularly, according to the manufacturer’s instructions.
  • Avoid mosquito-prone areas, especially at dusk and dawn when mosquitoes are more active and likely to bite.
  • Ensure that your accommodation has fly screens properly fitted to windows and external doors.
  • Reduce the number of potential mosquito breeding habitats around your home by ensuring no stagnant water is present. Containers holding water should be emptied and washed regularly.

Where to get help

  • Ross River virus and Barmah Forest virus - the facts, Communicable Disease Prevention and Control, Department of Health, Victorian Government. More information here.

More information


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This page has been produced in consultation with and approved by: Department of Health and Human Services - RHP&R - Health Protection - Communicable Disease Prevention and Control Unit

Last updated: November 2020

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