For Healthcare Providers
Ross River virus is an RNA virus in the genus Alphavirus (family Togaviridae) that was discovered near Ross River in Queensland, Australia in 1963.
Ross River virus is endemic in Australia and Papua New Guinea. There are approximately 4,000 cases of Ross River virus disease reported in Australia each year. Most cases there occur from January through April, but in some areas, disease occurs year-round. There was a large outbreak in 1979–1980 in many south Pacific islands including Fiji, American Samoa, New Caledonia, and the Cook Islands with over 50,000 reported cases. Since that time, cases have been reported in several travelers to Fiji, and serosurveys suggest that Ross River virus is either established or has been reintroduced multiple times in at least some Pacific island countries.
Clinical Signs and Symptoms
Patients with Ross River virus disease most commonly report polyarthritis, fever, fatigue and rash. Arthritis is usually symmetrical and involves peripheral joints, including knees, ankles, wrists, fingers, and metacarpophalangeal joints. Rash occurs primarily on the limbs and trunk and is typically maculopapular, with purpuric and vesicular rashes less common. Most symptoms resolve after a few weeks, but joint pain and fatigue can persist for six months or more. No fatal cases of Ross River virus disease have been reported.
Treatment and Outcome
Currently there are no specific medications or therapies for Ross River virus disease. Supportive therapy is recommended for any patient suspected of having Ross River virus disease. Over-the-counter pain relievers, rest, and physical therapy can be used to relieve some symptoms. In severe cases, patients may need to be hospitalized to receive supportive treatment, such as intravenous fluids, pain medication, and nursing care.
Testing for Ross River virus infection can be performed at the CDC. There are no commercially available tests for Ross River virus infection in the United States.
Please contact your state health department if you have a patient with an acute illness that might be compatible with Ross River virus infection (including appropriate travel history). You can find information on submitting diagnostic specimens here.
The differential diagnosis will vary depending on the travel destination of the patient. In travelers to Australia it might include other arboviral diseases, such as Barmah Forest virus disease, or non-arboviral diseases such as adenoviral, enteroviral, or rickettsial infections. In a traveler to Papua New Guinea or Pacific Island nations, possible arboviral diseases also include dengue, chikungunya, and Zika virus disease.