Ross River Fever, also known as Epidemic Polyarthritis, is a viral infection caused by the Ross River Virus belonging to the family. It is a zoonosis – an animal disease that can spread to humans – that affects kangaroos and wallabies. The illness is transmitted to humans through the bite of infected daytime biting female mosquitoes, primarily Aëdes vigilax, Aëdes camptorhynchus, and Culex annulorostris.
Ross River Fever is endemic in Australia and Papua New Guinea. Large outbreaks have also occurred on islands in the South Pacific. Travellers such as campers, hikers, hunter, and persons involved in outdoor professions or visiting farms near irrigation systems are at risk. Infections in urban areas are uncommon. Peak transmission occurs from January to March during the wet season.
In some cases, infection is asymptomatic – persons do not exhibit symptoms. Flu-like symptoms develop 7 to 10 days (up to 21 days) after exposure to the virus and include fever, chills, headache, fatigue, muscle pain. Almost all patients develop joint swelling (arthritis) affecting fingers, wrists, and knees. Some patients get a rash on their body, legs, and arms which disappears after 7 to 10 days. Joint pain, depression, and fatigue can persist for months after becoming ill. Treatment includes supportive care of symptoms. Note that Ross River Fever can be misdiagnosed as Dengue, Chikungunya or other similar viral infections.
Travellers should take measures to prevent mosquito bites both indoors and outdoors. There is no preventive vaccine or medication against Ross River Fever.
Health risk description last reviewed: September 15, 2016
Country information last updated: November 21, 2017