''Barmah Forest virus'' is an RNA virus in the genus ''

Alphavirus ''Alphavirus'' is a genus of RNA viruses, the sole genus in the ''Togaviridae'' family. Alphaviruses belong to group IV of the Baltimore classification of viruses, with a positive-sense, single-stranded RNA genome. There are 32 alphaviruses ...

''. This disease was named after the

Barmah Forest The Barmah National Park, formerly Barmah State Park, is a national park located in the Hume region of the Australian state of Victoria. The park is located adjacent to the Murray River near the town of Barmah, approximately north of Melbourne ...

in the northern Victoria region of Australia where it was first isolated in 1974. Or The first documented case in humans was in 1986. As of 2015, it has been found only in Australia. Although there is no specific treatment for infection with the Barmah Forest virus, the disease is non-fatal and most infected people recover.Barmah Forest Virus
''Queensland Health''. Queensland Government. 11 May 2011. Retrieved 16 February 2012. The virus was discovered in 1974 in

mosquito Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin ''culex'' meaning " gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish for "li ...

es in the

in northern

Victoria Victoria most commonly refers to: * Victoria (Australia), a state of the Commonwealth of Australia * Victoria, British Columbia, provincial capital of British Columbia, Canada * Victoria (mythology), Roman goddess of Victory * Victoria, Seychelle ...

. The virus has gradually spread from the sub-tropical northern areas of Victoria to the coastal regions of New South Wales, Queensland and Western Australia (WA). People are more likely to contract the disease in summer and autumn in Australia. In the south west of WA, however, spring has been found to have the highest incidence.

Transmission

The virus can only be transmitted to humans by bites from infected

es. A number of mosquito species have been associated with vectoring the virus, including the ''

Aedes vigilax ''Aedes'' is a genus of mosquitoes originally found in tropical and subtropical zones, but now found on all continents except perhaps Antarctica. Some species have been spread by human activity: ''Aedes albopictus'', a particularly invasive sp ...

'' and ''

Culex annulirostris ''Culex annulirostris'', commonly known as the common banded mosquito, is an insect native to Australia, Fiji, Micronesia, the Philippines and Indonesia. It is regarded as a serious pest species throughout its range. Frederick Askew Skuse des ...

'' mosquito species. Direct contact with an infected person or animal does not cause infection. The virus is hosted mainly by

marsupial Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a ...

s, especially

possums Possum may refer to: Animals * Phalangeriformes, or possums, any of a number of arboreal marsupial species native to Australia, New Guinea, and Sulawesi ** Common brushtail possum (''Trichosurus vulpecula''), a common possum in Australian urban a ...

kangaroo Kangaroos are four marsupials from the family Macropodidae (macropods, meaning "large foot"). In common use the term is used to describe the largest species from this family, the red kangaroo, as well as the antilopine kangaroo, eastern ...

s and wallabies.

Symptoms

Symptoms include

fever Fever, also referred to as pyrexia, is defined as having a temperature above the normal range due to an increase in the body's temperature set point. There is not a single agreed-upon upper limit for normal temperature with sources using val ...

, malaise, rash,

arthralgia Arthralgia (from Greek ''arthro-'', joint + ''-algos'', pain) literally means ''joint pain''. Specifically, arthralgia is a symptom of injury, infection, illness (in particular arthritis), or an allergic reaction to medication. According to MeSH, ...

, and muscle tenderness. Fever and malaise generally disappear within a few days to a week, but other symptoms such as joint pain may continue for six months or longer. The Barmah Forest virus causes similar symptoms as the Ross River virus, although they usually persist longer in persons infected with the latter.Ross River Virus & Barmah Forest Virus in WA
. ''Environmental Health Directorate''. Department of Health, Western Australia 2006. Retrieved 16 February 2012. Most people may recover within a few weeks, but the minority can continue to have the symptoms for many months, and in the most severe cases, up to a year. A full recovery will be expected.

Diagnosis

The Barmah Forest virus is diagnosed by examination of blood serum collected from potentially infected people.

Documented cases

Barmah Forest virus is the second most prevalent

arbovirus Arbovirus is an informal name for any virus that is transmitted by arthropod vectors. The term ''arbovirus'' is a portmanteau word (''ar''thropod-''bo''rne ''virus''). ''Tibovirus'' (''ti''ck-''bo''rne ''virus'') is sometimes used to more sp ...

in Australia. It is causing an epidemic

polyarthritis Polyarthritis is any type of arthritis that involves 5 or more joints simultaneously. It is usually associated with autoimmune conditions and may be experienced at any age and is not sex specific. Causes Polyarthritis is most often caused by an au ...

throughout the country. No known deaths have been caused as a result of Barmah Forest virus. It can affect all people regardless of age, gender or ethnicity. During the years of 1995–2008, 15592 cases of Barmah Forest virus were recorded in Australia. Of these, Queensland recorded the highest number of cases being 8050, which was over 50% of all cases. In 2011, 1855 people were diagnosed with Barmah Forest virus. In recent years, there has been an increasing number of Barmah Forest virus cases in Australia. This increase could be as a result of urban development and changes to land and irrigation practices which ultimately allow for increased mosquito breeding, resulting in more outbreaks.

Prevention

The type of mosquito that transmits the virus can alter: the best way to ascertain an area is affected is by contact with local Health Officers. Precautions include: * Removing water build-up to stop mosquitos from breeding. * In the afternoon and early evening wear light coloured clothing which is loose fitted. * Regular use of insect repellent which can be used against mosquitos on exposed skin. * 'Knock-down' insecticide before bed to clear out your house. * Insect screening, including fireplaces, in hot weather.

Treatment

There is currently no specific treatment for the virus. The only treatment is trying to control and get rid of the symptoms that may occur. A doctor will advise and give treatment for the joint and muscle pain which involves resting and gentle exercise (to keep joints moving) . Medication may sometimes be necessary, but not always.

References

External links

*
Ross River and Barmah Forest viruses

Queensland Public Health Services: Barmah Forest Virus

{{Taxonbar, from=Q3560914 Alphaviruses Diseases and disorders in Australia Insect-borne diseases