Ross River virus and Barmah Forest virus

Ross River virus and Barmah Forest virus

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What are Ross River virus and Barmah Forest virus?

Ross River virus and Barmah Forest virus are infections spread by the bite of an infected mosquito.

These viruses are related and cause a similar illness.

Ross River virus is mostly acquired during the summer months when weather is warmer and mosquitoes are more active.

Outbreaks can occur when local conditions of rainfall, tides and temperature promote mosquito breeding.

Barmah Forest virus is relatively common in mainland states but has not been thought to be present in Tasmania until recently.

What are the symptoms?

Many people will not develop symptoms.

However, if they do develop symptoms, these can include:

  • fever
  • headache
  • aches and pains in muscles and joints
  • tiredness
  • rash
  • swollen or stiff joints.

Symptoms usually develop three to 21 days after being bitten by an infected mosquito. Most people recover completely in a few weeks.

How are they diagnosed?

These viruses are diagnosed by a blood test. Two blood tests may be needed two weeks apart. Other illnesses with similar symptoms may need to be ruled out.

How are they treated?

There is no specific vaccine or treatment for either infection. Your doctor will advise you on medication to ease the discomfort of symptoms such as joint pain and fever.

As there is no treatment, prevention by avoiding mosquito bites is important.

How are they spread?

Both Ross River and Barmah Forest virus infections are spread by certain types of mosquitoes. When a female mosquito feeds on the blood of an infected animal, the mosquito may become infected with the virus.

The virus may then be passed on to humans when the mosquito feeds again. The virus is not spread from person-to-person. A mosquito is always involved.

Where are they found in Tasmania?

Ross River virus can be found in coastal regions extending from the North (including the islands of eastern Bass Strait), down the East Coast to the South Eastern corner of Tasmania.

These areas have mosquitoes that can transmit both Ross River virus and Barmah Forest virus. So far Barmah Forest virus seems localised to the East Coast.

How can they be prevented?

Protect yourself against mosquito bites.

  • Avoid known mosquito-infested areas, where possible.
  • Take extra care during peak mosquito biting hours, especially around dawn and dusk and when outdoors or camping.
  • Wear loose fitting, light colored clothing that covers as much of your body as possible. Mosquitoes can bite through tight fitting clothing.
  • Use insect repellents containing DEET (Diethyl toluamide) or picaridin on exposed skin. Always read the manufacturer's instructions before applying it.
  • Remove potential mosquito breeding sites from around the home (eg containers that collect water).
  • Use insect screens on your house, caravan or tent. If this is not possible, use a mosquito net.

March 2019