Ross River Fever

Last updated: 16 January 2008

What is the Ross River fever?

Ross River virus is one of a group of viruses called arboviruses (or arthropod-borne viruses), which are spread mainly by blood-sucking insects.

What are the symptoms?

Many people who are infected with the virus will never develop symptoms.

• Some people will have flu-like symptoms that include fever, chills, headache and aches and pains in the muscles and joints.
• Some joints can become swollen, and joint stiffness may be particularly noticeable in the morning.
• Sometimes a rash occurs on the body, arms or legs. The rash usually disappears after seven to 10 days.
• A general feeling of being unwell, tired or weak may also occur at times during the illness. This may affect work performance.

How is the virus spread?

The virus is spread by certain types of female mosquitoes.

• Female mosquitoes feed on animals and people. If they feed on the blood of an infected animal, the mosquito may become infected. The virus then multiplies within the mosquito and is passed to other animals or people when the mosquito feeds again.
• The number of infections tends to peak in the summer and autumn months.
• The virus is not spread directly from one person to another.
• Approximately 30 per cent of people infected with the virus will develop symptoms three to eleven days after being infected.

Who is at risk?

People who are in contact with known mosquito habitats and who live in warm, humid climates near bodies of water will be most at risk of a mosquito bite and as a consequence the Ross River virus.

How is it prevented?

• Avoid being bitten by mosquitoes, especially in the summer and autumn months when infections are more common.
• Various species of mosquitoes bite at different times. Avoid being outside in the late afternoon and dusk. Mosquitoes are usually most active up to one to three hours after sunset and again around dawn.
• When outside wear loose fitting, light coloured clothing that covers your arms and legs, and use an insect repellent that contains the chemical diethyl toluamide (DEET) or picardin.
• Fit fly screens to all windows, doors and chimneys and keep them in good repair.
• Use a knockdown insecticide in bedrooms half an hour before going to bed. Use insecticides according to instructions.
• Ensure open containers of water are removed from around the home to prevent mosquitoes breeding. Cover the openings to water tanks with fine steel mesh to prevent mosquitoes from laying eggs in the tank.
• When camping take precautions such as using flyscreens on caravans and tents and by sleeping under mosquito proof nets. Take particular care while fishing, ensuring that you follow personal precautions to avoid being bitten by mosquitoes.

How is it diagnosed?

Ross River infection is diagnosed by detection of antibodies against the virus in the blood. Blood test taken early in the illness and again two weeks later may be required to confirm the infection.

How is it treated?

There is no specific treatment for Ross River virus infection.

• Your doctor will be able to advise you on medications that will help ease the discomfort of the symptoms.

What is the public health response?

Laboratories are require to notify cases of Ross River, and other mosquito-borne disease to the public health unit. Public health staff monitor the geographic spread of Ross River virus infections and provide information about avoiding mosquito-dorne diseases.