DEFINITION

Barmah Forest Virus is an alphavirus found widely across Australia. It is transmitted by the mosquito and causes acute polyarthritis. It is not fatal and cannot be transmitted from one human to another.

DESCRIPTION

Barmah Forest and Ross River viruses are the two most common mosquito-borne viruses associated with epidemic polyarthritis. Of these, Ross River accounts for about 90% and Barmah Forest for the remaining 10%. Illness caused by the Barmah Forest virus has only been identified since 1988. Australia is the only country in which this virus has been detected. Many cases are misdiagnosed as Ross River virus, due to the similarity of the diseases.

Several outbreaks of Barmah Forest have been noted in recent years, with the number of reported cases increasing annually. While the virus is thought to be widespread, outbreaks are linked to environmental conditions which affect the mosquito. Increases in rainfall, tides and temperature for parts of Australia are predicted. Such changes have the potential to increase the risk of virus transmission due to a rise in mosquito population. It is likely that this rise, as well as increased travel, will lead to an increase in the incidence of Barmah Forest Virus in the near future.

PREVENTION

Avoid mosquito bites.
- Stay indoors during early evening when mosquitoes are biting.
- Wear light coloured, long sleeved shirts and trousers.
- Use an effective personal insect repellent.
- Try planting citronella (a natural insect repellent) in your garden.
- Install insect screens in your home, particularly in bedrooms.
- Remove potential breeding areas from your environment. Examples include old tyres, wading pools, water containers, ponds and pot plant bases.

SIGNS AND SYMPTOMS

Some people, particularly children, who are exposed to Barmah Forest Virus will not develop symptoms. For those who do, symptoms usually appear within 3-11 days after being bitten by an infectious mosquito.
The initial symptoms are usually:
- fever - adults and lethargy lasting a few days,
- Arthritis and swelling mainly in ankles, knees, wrists and elbows,
- A mild skin rash which may last up to a week,
- Headache.

Arthritis and muscle tenderness can last for more than six months and may require some people to have extended time off work.
While Barmah Forest Virus is considered a relatively mild illness, it has been linked to complications such as Guillain-Barre syndrome, anaemia and glomerulonephritis (kidney inflammation).

TREATMENT OPTIONS

There is no cure for Barmah Forest Virus. Treatment is aimed at relieving symptoms.
- During the initial stages, rest and drinking plenty of fluids is recommended.
- Gentle exercise, such as walking, swimming or water aerobics, is important to maintain joint mobility.
- Simple analgesics may be used for relief of fever and joint pain.

DIET HINTS

- Fish Oil is rich in Omega-3 fatty acidswhich help decrease the severity of arthritis symptoms and help regulate the number of molecules in the body which cause inflammation. Mackerel, tuna, salmon, sardines and halibut are good sources.
- During a fever, drink plenty of fluids to prevent dehydration. Fruit juice, thin soups, herbal tea and filtered water are good.
- A low-fat, low-cholesterol and low-sugar diet is beneficial in fighting off infection.

VITAMINS/MINERALS/HERBS

- Vitamin C is beneficial in fighting off infection and maintaining general good health.
- Vitamin E is used to boost the immune system and prevent infection, and can enhance the action of essential fatty acids.
- Omega-3 fatty acids present in evening primrose, fish and linseed oils appear to have anti-viral actions.
- Garlic is used to fight a wide range of infectious agents.
- Citronella oil is an effective insect repellent. It used in lotions or creams, or as a lamp oil for burning. It should not be ingested.

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