What is Ross River virus infection?

Ross River virus infection (also known as Ross River fever and epidemic polyarthritis) is caused by an alphavirus. It is spread to humans by infected mosquitoes.

Other diseases caused by alphaviruses are:

• Barmah Forest virus
• chikungunya virus

Ross River virus infection is the most common mosquito-borne disease in Australia. It's also found in Papua New Guinea and the Solomon Islands.

In Australia, it's more common in the tropical areas of Queensland and the Northern Territory.

Ross River virus infection is more common:

• in seasonal wet and warm conditions
• after heavy rainfall
• after high tides

What are the symptoms of Ross River virus infection?

People who are infected with Ross River virus can have a wide range of symptoms. Some people may not feel sick at all, while others can have long-lasting and serious symptoms.

The illness usually begins with painful joints (arthralgia) and muscle pain. The joints that are most affected are:

• wrists
• ankles
• knees

Other symptoms include:

• fever and chills
• headache
• muscle pain
• joint pain and swelling
• rash
• fatigue (tiredness)

Symptoms can appear anywhere from 3 to 21 days after being bitten by an infected mosquito. Usually, you will feel symptoms for around 7 to 9 days.

How long does it last?

It's not possible to say how long Ross River virus infection will last for an individual. Most symptoms will get better in a few days to weeks, but some people may experience painful joints for 3 to 6 months after diagnosis. Severe joint pain and tiredness have also been reported to last up to 12 months for people with other conditions, such as rheumatological (muscle and joint) conditions or depression.

What causes Ross River virus infection?

You can catch Ross River virus infection if you are bitten by an infected mosquito.

Outbreaks of Ross River virus infection can occur when and where mosquitoes breed. The highest risk is in warm, humid areas near water.

Ross River virus infection does not spread from person to person.

Climate change is likely to lead to more summertime wet weather events in south‐east Australia. This is likely to increase rates of Ross River virus infection.

When should I see my doctor?

See your doctor if you have symptoms of Ross River virus infection.

How is Ross River virus infection diagnosed?

Your doctor can diagnose Ross River virus infection by examining you. They may also ask you questions about where you live or have recently visited. This is to work out if you have a high risk of becoming infected.

Your doctor will organise a blood test to measure your antibody levels to the virus. You'll need to have 2 blood tests: one when you're sick, and another 2 weeks later. This is so your doctor can compare your levels of antibodies.

Ross River virus infection is a notifiable disease. This means that if you have Ross River virus infection, the lab must tell the local public health authority. They may ask to speak with you to try and find out where you caught the infection.

How is Ross River virus infection treated?

Treatment for Ross River virus infection focuses on relieving symptoms, as there are no approved vaccines or antiviral drugs yet.

Pain relief medicines such as anti-inflammatory medicines (such as ibuprofen) can help ease your symptoms.

It's also important to rest.

What are the complications of Ross River virus infection?

Some people may still experience severe joint pain and tiredness up to a year after diagnosis.

In rare cases, Ross River virus infection can cause problems such as:

• an enlarged spleen
• kidney problems
• blood in the urine (haematuria)
• meningitis
• encephalitis

Ross River virus infection has also been linked to bone loss and lower bone volume.

Can Ross River virus infection be prevented?

There is no vaccine for Ross River virus, so preventing mosquito bites is important. Here are some tips to protect yourself:

• Use an insect repellent on exposed skin.
• Cover up when you're outside, with light-coloured clothing and covered footwear.
• Stay indoors at dawn and dusk when mosquitoes are most active.
• Cover windows, doors, vents and other entrances with flyscreens.
• Remove any containers of water from around your home — to stop mosquitoes breeding.
• Sleep under a mosquito net.

Try to take extra steps to avoid mosquito bites after intense summertime rain. Research has shown that mosquito numbers rise about 2 weeks after rain.

Resources and support

More information:

• Visit the SA Health website to learn more about mosquito bites and how to prevent them.
• Read the Queensland Health fact sheet on staying safe around mosquitoes.
• Read the Arthritis Australia guide to managing Ross River virus.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.

Languages other than English

The Northern Territory Government has information on Ross River virus infection in many community languages.

Information for Aboriginal and/or Torres Strait Islander peoples

• Aboriginal Health Council offers information on how to fight the bite and mosquito control.
• Australian Indigenous HealthInfoNet offers information on personal protection from mosquitoes and biting midges.