Barmah Forest virus is an RNA virus classified within the genus Alphavirus of the family Togaviridae, belonging to a group of mosquito-transmitted arthritogenic alphaviruses that cause human rheumatic disease.[1][2][4]
Disease overview
Barmah Forest virus infection
巴马森林病毒感染
Evidence-backed informationEN 5/7 applicable sections · ZH 5/7 applicable sectionsUpdated Sep 3, 2026
Barmah Forest virus is a mosquito-borne alphavirus endemic to Australia, first isolated in 1974 from the Barmah Forest in northern Victoria, with the first human case documented in 1986.[1][2] Although infection is generally non-fatal and most patients recover, it can produce prolonged arthralgic and rheumatologic manifestations.[1][2] The virus has been the subject of targeted public-health surveillance and outbreak investigation across Australian jurisdictions, with documented local transmission events outside its historical range.[1][3]
Read the full clinical and epidemiological profile6
Clinical illness is characterized by fever, malaise, rash, arthralgia and muscle tenderness, with fever and malaise typically resolving within several days to a week.[1][4] Joint symptoms, however, may persist for several months and, in the most severe cases, up to a year, although full recovery is expected.[1] The clinical picture resembles that of Ross River virus disease, although joint symptoms generally last longer in Ross River virus infections.[1][2]
Barmah Forest virus is widespread across Australia, with some evidence of local transmission in Papua New Guinea, and has gradually extended from subtropical northern Victoria into coastal regions of New South Wales, Queensland and Western Australia.[1] Notifications are highest in summer and autumn across most regions, although in south-western Western Australia the peak occurs in spring.[1] The first confirmed outbreak in Tasmania was recorded between January and May 2019, comprising eight cases acquired locally in the Break O'Day Local Government Area, and a retrospective review identified 27 confirmed notifications in the Tasmanian notifiable diseases database from 1999 to 2019.[3]
The virus is transmitted to humans almost exclusively through the bites of infected mosquitoes, with vector species including Aedes vigilax and Culex annulirostris.[1] Direct contact with infected humans or animals does not result in transmission.[1] Reservoir hosts are mainly marsupials, particularly possums, kangaroos and wallabies.[1]
Because transmission depends entirely on mosquito vectors, prevention centres on mosquito-bite avoidance and vector-control measures; the identification of known vector species in saltmarsh and urban-fringe habitats in Tasmania has informed the development of targeted, prevention-focused public health messaging in Australian jurisdictions.[3] Broader review evidence also indicates a positive association between high temperatures and notification rates, with spatial variation between inland and coastal regions that should inform tailored regional prevention strategies.[5]
- 1Wikipedia contributors. Barmah Forest virus - Wikipedia [Internet]. Wikipedia. cited 3 Sept 2026.Available from: https://en.wikipedia.org/wiki/Barmah_Forest_virus
- 2Suhrbier A et al. Arthritogenic alphaviruses--an overview. Nat Rev Rheumatol. 2012 May 8. PMID: 22565316. doi: 10.1038/nrrheum.2012.64.PubMed: https://pubmed.ncbi.nlm.nih.gov/22565316/
- 3Dyke H et al. The first confirmed outbreak of Barmah Forest virus in Tasmania - 2019. Aust N Z J Public Health. 2023 Apr. PMID: 37004338. doi: 10.1016/j.anzjph.2023.100039.PubMed: https://pubmed.ncbi.nlm.nih.gov/37004338/
- 4Lopes Marques CD et al. Arboviruses related with chronic musculoskeletal symptoms. Best Pract Res Clin Rheumatol. 2020 Aug. PMID: 32312678. doi: 10.1016/j.berh.2020.101502.PubMed: https://pubmed.ncbi.nlm.nih.gov/32312678/
- 5Varghese CM et al. The impact of temperature on Ross River virus and Barmah Forest virus infection in Australia: A scoping review. Aust N Z J Public Health. 2026 Feb. PMID: 41407624. doi: 10.1016/j.anzjph.2025.100291.PubMed: https://pubmed.ncbi.nlm.nih.gov/41407624/
Coverage
Reporting countries and regions
Trends by reporting country
Monthly patterns over time
Data access
Page dataset index with source links and update metadata.
Official sourcesAuthority, cadence, notes9
Australia NINDSS
Australia
Australian national notifiable diseases surveillance dashboard.
Australia NINDSS — Australian Capital Territory
Australian Capital Territory, Australia
Australian NINDSS monthly state/territory notifications for Australian Capital Territory, kept separate from the Australia national aggregate.
Australia NINDSS — New South Wales
New South Wales, Australia
Australian NINDSS monthly state/territory notifications for New South Wales, kept separate from the Australia national aggregate.
Australia NINDSS — Northern Territory
Northern Territory, Australia
Australian NINDSS monthly state/territory notifications for Northern Territory, kept separate from the Australia national aggregate.
Australia NINDSS — Queensland
Queensland, Australia
Australian NINDSS monthly state/territory notifications for Queensland, kept separate from the Australia national aggregate.
Australia NINDSS — South Australia
South Australia, Australia
Australian NINDSS monthly state/territory notifications for South Australia, kept separate from the Australia national aggregate.
Australia NINDSS — Tasmania
Tasmania, Australia
Australian NINDSS monthly state/territory notifications for Tasmania, kept separate from the Australia national aggregate.
Australia NINDSS — Victoria
Victoria, Australia
Australian NINDSS monthly state/territory notifications for Victoria, kept separate from the Australia national aggregate.
Australia NINDSS — Western Australia
Western Australia, Australia
Australian NINDSS monthly state/territory notifications for Western Australia, kept separate from the Australia national aggregate.