Centre for Disease Control Barmah Forest virus January 2013

What is Barmah Forest virus Although the symptoms of BFV are similar to those of RRV disease the disease is generally disease? milder. Symptoms include painful (sometimes Barmah Forest virus (BFV) disease is the swollen) joints and muscle and tendon pain. second most common arbovirus after Ross The most commonly affected joints are the River virus (RRV) in the Northern Territory ankles, fingers, knees and wrists. Other (NT). It is characterised by painful or swollen symptoms include a raised red rash affecting joints lasting from days to months. Symptoms mostly limbs and trunk (this may be more usually settle by themselves. florid than the rash of RRV), fever, fatigue, and headache. How is it spread? Fever, nausea and the skin rash usually BFV infection cannot be spread from person disappear within the first 1 or 2 weeks of to person. The virus is transmitted to humans illness. In a minority of cases lethargy, joint, by the bite of an infected mosquito. The muscle and tendon pain may last for over 6 mosquitoes present in the NT that can months. spread the virus are Aedes vigilax (salt marsh mosquito), Culex annulirostris (common Symptoms subside eventually and leave few banded mosquito), Aedes normanensis or no after-effects. It is not possible at present (flood water mosquito) and Aedes to say how long an individual person will take notoscriptus (backyard mosquito). Many to get better. people, particularly children, even if bitten As a rule, once you have had BFV once, by an infected mosquito, do not develop any you will not get it again. symptoms of the disease. Children tend to have infection without Where and when is the virus symptoms or experience milder symptoms of shorter duration than adults. found? BFV was first isolated in northern Victoria and What is the treatment? has been detected in most parts of mainland BFV infection is diagnosed by a blood test. Australia. There is no vaccine to prevent BFV infection, In the NT, the main risk season is from and there is no medical cure for the disease. December to May inclusive with the highest Medical treatment is aimed at easing joint risk period usually in February when large pains and swelling, and minimising fatigue numbers of mosquitoes result from either and lethargy. For some people, simple pain- high tides or increased rainfall. Humid killers like aspirin or paracetamol are sufficient. conditions enable mosquitoes to live longer, Others will require stronger medications to which allows more chance for a mosquito ease the inflammation. to pick up a virus from an animal and to live Emotional stress, physical fatigue and alcohol long enough to pass it on to humans. may cause symptoms to worsen or to last Since 1992 there have been between 11 longer. and 130 cases reported annually in the NT. How can it be prevented? What are the symptoms? Try to reduce the number of places on your Symptoms vary from person to person and property where mosquitoes can breed. most commonly appear within 3 to 11 days after being bitten.

www.nt.gov.au/health Barmah Forest virus CENTRE FOR DISEASE CONTROL

Any pools of water, even if tiny, can provide • Use mosquito coils, or candle heated or breeding sites for mosquitoes. gas operated devices using insecticide treated pads for patio and veranda or The only protection from BFV is to avoid being relatively sheltered or low wind outdoor bitten by mosquitoes. situations. Personal protective measures For more information on protection measures • Stay indoors when mosquitoes are most see Personal protection from mosquitoes. active, from just before, until 2 hours after sunset. For more information contact your • Ensure flyscreens in houses or caravans nearest Centre for Disease Control. are in good condition. Darwin 8922 8044 • If camping out sleep in a mosquito-proof Katherine 8973 9049 tent or under a mosquito net. Repellents Alice Springs 8951 7540 only protect against mosquito bites for up Tennant Creek 8962 4259 to four hours, not all night. Nhulunbuy 8987 0357 • Avoid scents on the body, e.g. perfume, deodorants, and sweat, since these can or www.nt.gov.au/health/cdc attract mosquitoes. For more information on mosquitoes and • Use personal repellents containing DEET virus ecology contact or picaridin on areas of exposed skin in Centre for Disease Control, combination with protective clothing. Medical Entomology on 8922 8901. • Use electric insecticide devices using For more information regarding support repellent treated pads in indoor or enclosed groups and education call the Arthritis areas. Foundation of the NT on 8948 5232.

www.nt.gov.au/health Barmah Forest virus