Barmah Forest virus infection

About Barmah Forest virus infection

Barmah Forest virus infection can cause fever, a rash of variable appearance, joint inflammation and pain, muscle aches and fatigue. 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, clothes and use insect repellent containing DEET or Picaridin to help reduce the chance of being bitten by mosquitoes.

Symptoms of Barmah Forest virus infection

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 and severity vary from person to person, but can include:

• fever
• chills
• headache
• tiredness or fatigue
• joint pain and swelling – 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
• swollen lymph nodes

Some people, particularly children, may show no symptoms.

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.

Transmission of Barmah Forest virus

People can be infected with Barmah Forest virus when they are bitten by a mosquito carrying the virus. It is suspected 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.

The virus is not spread directly from one person to another.

Barmah Forest virus infection 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 2021.

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.

Diagnosis of Barmah Forest virus infection

Blood tests can reveal if a person has been infected with Barmah Forest virus recently or in the past.

Prevention of Barmah Forest virus infection

There is no preventive vaccine available. Your only protection against Barmah Forest virus and the most effective way to prevent other mosquito-borne diseases is is by avoiding mosquito bites and removing mosquito breeding sites around your home and property.

How to protect yourself from mosquitoes

Protect yourself and your family from exposure to mosquitoes and mosquito-borne diseases:

• Wear long, loose fitting clothes and covered shoes outdoors.
• Use mosquito repellents containing Picaridin or DEET on all exposed skin.
• Limit outdoor activity if lots of mosquitoes are about.
• Use ‘knockdown’ fly sprays and plug-in repellent devices indoors.
• Cover all windows, doors, vents, and other entranced with insect screens.
• Sleep under mosquito nets treated with insecticides if you don’t have flywire screens on windows on your home or are sleeping in an untreated tent or out in the open.
• Mosquito coils can be effective in small outdoor areas where you gather to sit or eat.
• Make sure there is no stagnant water around your home or property by emptying pots and containers at least once a week.
• Visit our Protect yourself from mosquito-borne disease page for more information.

Treatment for Barmah Forest virus infection

There is no specific treatment available for Barmah Forest virus infection. Your doctor will be able to advise you on treating the symptoms.

Where to get help

• Your GP (doctor)
• Your local council
• Nurse-on-Call Tel. 1300 60 60 24 – for confidential health advice from a registered nurse, 24 hours a day, 7 days a week
• Department of Health, Communicable Disease Prevention and Control, Victorian Government. Tel. 1300 651 160
• Beat the bite