Ross River Virus
Ross River virus (sometimes called epidemic polyarthritis) is a disease caused by a virus which is spread by the bite of an infected mosquito. Ross River virus disease occurs widely in Australia. In northern and central Queensland, cases of Ross River virus occur throughout the year, but most cases occur between February and May. Everybody who becomes infected with Ross River virus will recover, however, the time taken to recover fully is prolonged in some people.
Ross River virus causes inflammation and pain in multiple joints (epidemic polyarthritis). The symptoms may include fever with joint pain and swelling which may then be followed in one to ten days by a raised red rash affecting mainly the trunk and limbs. The rash usually lasts for one to ten days and may or may not be accompanied by a fever. The joint pain can be severe and usually lasts two to six weeks. Some people, especially children, may become infected without showing any symptoms.
Most people become unwell within three to 11 days after being bitten by an infectious mosquito.
Ross River virus infection cannot be spread from human to human. Ross River virus is spread from animals to humans by a number of different types of mosquitoes with Culex annulirostris, Aedes vigilax (salt marsh mosquito) and Aedes notoscriptus being most common. Aedes vigilax breeds in salty pools in mangroves and salt marshes after flooding by spring tides and heavy rains. Culex annulirostris breeds in permanent bodies of fresh water while Aedes notoscriptus breeds in containers close to homes and other human activity such as bird baths, pot plant saucers and backyard rubbish holding water.
There is no specific drug treatment for Ross River virus infection. Treatment involves managing the symptoms that develop. Your doctor will advise on treatment for joint and muscle pains. A combination of plenty of rest and gentle exercise are important to keep joints moving and to prevent overtiredness, but medication may sometimes be necessary.
The best prevention is to take precautions against being bitten by mosquitos:
- avoid being outside during times of heavy infestation of mosquitoes eg. early evenings in the warmer months
- use insect repellents and wear protective, light coloured clothing
- screen living and sleeping areas
- check your home regularly for potential mosquito breeding areas eg. any uncovered water containers should be emptied regularly.
Mosquito eradication programs are the most effective way to control spread of Ross River virus. Health officers from most local councils and state health departments work together to develop and implement mosquito eradication programs.