Kunjin virus disease

Kunjin virus has been shown to be closely related to West Nile virus and is usually referred to as West Nile virus Kunjin subtype.

Kunjin virus is spread by the bite of an infected mosquito. Although only a small number of cases of Kunjin are reported annually, the virus is known to occur in many parts of Australia.

Signs and Symptoms

Symptoms of Kunjin virus disease vary. The vast majority of infected people do not develop any symptoms. A small number of people may experience a mild illness with symptoms including fever, headache, muscle pain, swollen lymph nodes, fatigue and rash. Some of those people may experience inflammation of the brain, known as encephalitis. Symptoms of encephalitis may include confusion, drowsiness and seizures (fits). Those with encephalitis will usually require hospitalisation.


Kunjin virus infection is diagnosed by antibody tests performed on blood samples. Two blood samples will usually be required, the first taken when the person is sick and the second two weeks later, to look for a change in antibody levels.

There is no specific treatment for the disease. Your doctor or health care professional can advise you on the most appropriate management of symptoms.


The main mosquito associated with the spread of Kunjin virus is Culex annulirostris which is geographically widespread and is associated with fresh water habitats. Wading birds, such as herons, are associated with spread of the virus to mosquitoes. The virus cannot be spread directly from person to person.


There is no vaccine for Kunjin virus disease. The only way to prevent the disease is to prevent being bitten by infected mosquitoes.

To prevent being bitten by mosquitoes that may transmit Kunjin:

  • Stay indoors when mosquitoes are most active, from just before sunset after dawn.
  • Wear loose, light-coloured clothing with long sleeves, long trousers and socks (mosquitoes can bite through tight-fitting clothes).
  • Apply a protective repellent contain­ing up to 20 percent diethyl toluamide (DEET) or picaridin to exposed areas of skin and reapply as directed by the manufacturer. Lotions and gels are more effective and long lasting than sprays.
  • Use other mosquito protection devices such as mosquito lanterns.
  • Apply residual pyrethroids around the home or campsite, and/or to nearby shrubbery that provide a harbourage for mosquitoes.
  • Ensure flyscreens in houses or caravans are in good condition.
  • If camping out, sleep in a mosquito-proof tent or under a mosquito net. Repellents only protect against mosquito bites for up to four hours, not all night.
Other resources
Help and assistance

For further information contact your local doctor, or nearest public health unit, or refer to Mosquito borne disease in Queensland