Barmah Forest virus infection - including symptoms, treatment and prevention

This is an illness caused by infection with the Barmah Forest virus, which is related to Ross River virus.

Barmah Forest virus infection is a notifiable condition1

How Barmah Forest virus infection is spread

Barmah Forest virus infection is spread by mosquitoes from infected animals to humans. Native animals, such as wallabies and kangaroos, are thought to be the main animals involved in the cycle of infection. When a female mosquito feeds on the blood of an infected animal, the mosquito may become infected with the virus. The virus may subsequently be passed on to humans or other animals when the mosquito feeds again.

Signs and symptoms of Barmah Forest virus infection

Many people infected with the Barmah Forest virus will not develop any symptoms, but others may develop:

  • rash, usually on the trunk or limbs
  • joint pain, which may persist for more than 6 months
  • tiredness and weakness
  • joint swelling and stiffness
  • flu-like symptoms, with fever, chills and headache
  • muscle aches and pain
  • swollen lymph glands.

Most people will recover completely within a few weeks but in a few people the symptoms may persist for several months, and very rarely for more than a year. A full recovery can be expected.

Diagnosis of Barmah Forest virus infection

Diagnosis is made by blood tests. Since there are other illness with similar symptoms, blood tests are usually required to confirm the diagnosis.

Incubation period

(time between becoming infected and developing symptoms)

Usually 7 to 10 days, but may be up to 21 days.

Infectious period

(time during which an infected person can infect others)

Direct person-to-person spread does not occur.

Treatment for Barmah Forest virus infection

There is no specific antiviral treatment available.

General recommendations include controlling fever and pain with paracetamol and increasing fluid intake. Aspirin should not be given to children under 12 years of age unless specifically recommended by a doctor.

Prevention of Barmah Forest virus infection

  • Exclusion of cases from childcare, preschool, school or work is not necessary but cases should avoid being bitten by mosquitoes while they are unwell.
  • There is no vaccine to prevent infection.
  • Personal protection and the environmental management of mosquitoes are important in preventing illness. For more information on how to protect yourself, see Fight the Bite.

Useful links 

1 – In South Australia the law requires doctors and laboratories to report some infections or diseases to SA Health. These infections or diseases are commonly referred to as 'notifiable conditions'.