Barmah Forest virus is an RNA virus classified within the genus Alphavirus, named for the Barmah Forest region of northern Victoria where it was first identified in 1974 [1]. It is an arbovirus transmitted to humans exclusively through infected mosquito bites and is maintained in nature primarily by marsupial hosts such as possums, kangaroos, and wallabies [1].
Disease overview
Evidence-backed information EN 5/7 applicable sections · ZH 5/7 applicable sections Updated Oct 23, 2026
Barmah Forest virus is an RNA alphavirus first isolated in northern Victoria, Australia, in 1974, with the initial human case recorded in 1986 [1]. It is widespread across Australia with some local transmission reported in Papua New Guinea and a confirmed outbreak in Tasmania in 2019 [1][2]. The disease is non-fatal, mosquito-borne, and typically resolves with full recovery, though joint symptoms may persist for months in some individuals [1].
Read the full clinical and epidemiological profile 6
Infected persons commonly experience fever, malaise, rash, joint pain, and muscle tenderness [1]. Fever and malaise typically subside within days to a week, whereas arthralgia may continue for six months or longer in some cases, with most achieving full recovery within weeks to a year [1]. The symptom profile resembles that of Ross River virus infection but generally persists less long than the latter [1].
The virus is endemic throughout Australia and has expanded from subtropical northern Victoria to coastal New South Wales, Queensland, and Western Australia, with seasonal peaks in summer and autumn and a spring peak in southwest WA [1]. A retrospective review of Tasmania's notifiable disease database identified 27 confirmed cases from 1999 through June 2019, including an eight-case outbreak acquired locally in the Break O'Day area in early 2019 [2].
Human infection occurs solely through the bite of infected mosquitoes, with species such as Aedes vigilax and Culex annulirostris implicated as vectors [1]. Direct contact with infected people or animals does not transmit the virus, and the natural host reservoir is mainly marsupials including possums, kangaroos, and wallabies [1].
Evidence indicates a positive association between higher temperatures and increased BFV notification risk in Australia, with geographic variation suggesting that tailored prevention strategies should account for coastal and inland differences [3].
- 1 Wikipedia contributors. Barmah Forest virus - Wikipedia [Internet]. Wikipedia. cited 23 Oct 2026. Available from: https://en.wikipedia.org/wiki/Barmah_Forest_virus
- 2 Dyke 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/
- 3 Varghese 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/
- 4 Lopes 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/
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