Ross River fever
Ross River fever | |
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Specialty | Infectious diseases |
Ross River fever is a
Symptoms and signs
Symptoms of the disease vary widely in severity, but major indicators are arthralgia, arthritis, fever, and rash.[3] The incubation period is 7–9 days. About a third of infections are asymptomatic, particularly in children.[4][3]
Acute illness
About 95% of symptomatic cases report joint pain.[4] This is typically symmetrical and with acute onset, affecting the fingers, toes, ankles, wrists, back, knees and elbows.[3] Fatigue occurs in 90% and fever, myalgia and headache occur in 50–60%.[4]
A rash occurs in 50% of patients and is widespread and
Chronic illness
Reports from the 1980s and 1990s suggested RRV infection was associated with
Transmission
The virus can only be spread by
Diagnosis
A blood test is the only way to confirm a case of Ross River fever. Several types of blood tests may be used to examine antibody levels in the blood. Tests may either look for simply elevated antibodies (which indicate some sort of infection), or specific antibodies to the virus.[3]
Prevention
There is currently no vaccine available. The primary method of disease prevention is minimizing mosquito bites, as the disease is only transmitted by mosquitoes. Typical advice includes use of mosquito repellent and mosquito screens, wearing light coloured clothing, and minimising standing water around homes (e.g. removing
Treatment
Patients are usually managed with simple
Epidemiology
Most notifications are from Queensland, tropical Western Australia and the Northern Territory. Geographical risk factors include areas of higher rainfall and higher maximal tides.[4] In the tropics, Ross River fever is more prevalent during the summer/autumn "wet season", particularly January—March, when mosquito populations numbers are high. In southern parts of Australia, this time period may shift to earlier in the year during spring/summer. Areas noted of common place contraction of the virus include townships and along the River Murray areas. Backwaters and Lagoons are breeding grounds for mosquitos and local medical treating facilities report higher cases than cities away from the river around the riverina areas.[1][3]
Areas near suitable mosquito breeding grounds—marshes, wetlands, waterways and farms with irrigation systems—are high risk areas for outbreaks. As such, the disease is more characteristic of rural and regional areas.[3] Infection is most common in adults aged 25–44 years old, with males and females equally affected.[4] Ross River fever is on the Australian Department of Health and Ageing's list of notifiable diseases.[6]
History
The first outbreak of RRF was in 1928 in the
Before the identification of this infectious agent, the disease was referred to as "epidemic polyarthritis". This term was also used for a similar Australian disease caused by another mosquito-borne virus, Barmah Forest virus.[3]
Research
The study of RRF has been recently facilitated by the development of a mouse model. Mice infected with RRV develop hind-limb arthritis/arthralgia which is similar to human disease. The disease in mice is characterized by an inflammatory infiltrate including macrophages which are immunopathogenic and exacerbate disease. Furthermore, mice deficient in the C3 protein do not develop severe disease following infection.[7] This indicates that an aberrant innate immune response is responsible for severe disease following RRV infection.
References
- ^ a b c Ed Poliness (2006-01-19). "Fact file: Ross River fever". ABC Health & Wellbeing. ABC. Retrieved 2008-10-29.
- ^ Bolton, Meg; Mapstone, Tessa (17 November 2021). "Sunshine Coast leads Queensland for Ross River virus cases". ABC News. Australian Broadcasting Corporation. Retrieved 17 November 2021.
- ^ a b c d e f g h i j Russell RC, Doggett SL. "Ross River & Barmah Forest". Department of Medical Entomology, University of Sydney. Archived from the original on 2008-09-13. Retrieved 2008-10-29.
- ^ a b c d e f g h i j k l m "Australian Family Physician: Ross River virus" (PDF). Archived from the original (PDF) on 2011-07-17. Retrieved 2009-08-13.
- ^ "'Breakthrough' in Ross River Virus battle".
- ^ "Australian national notifiable diseases list and case definitions". National Notifiable Diseases Surveillance. Australia: Department of Health and Ageing. 2004-03-12. Retrieved 2008-11-29.
- PMID 17314163.