Some Mosquitos Carry Disease Don't Risk Being Bitten

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Mosquito-Borne Disease

A mosquito-born disease is a disease transmitted by mosquitoes to humans.


Victoria has three significant mosquito-borne diseases:

         Ross River Virus disease

(Epidemic Polyarthritis).

         Barmah Forest Virus disease.

         Australian Arboencephalitis.


Ross River Virus disease and Barmah Forest Virus disease are endemic throughout parts of Victoria and cases are reported each year. These diseases can be debilitating but not fatal.


Australian Arboencephalitis occurs in northern Victoria in epidemics with the last outbreak recorded in 1974. This disease can be fatal.



Ross River Virus Disease

Only about ten per cent of people infected with the disease actually develop symptoms. These may appear within two to twenty days after a mosquito bite and include:

         Fatigue, headache and feeling unwell.

         Joint pains, particularly in the larger joints.

         A rash on the body and limbs.


Symptoms may persist for more than three months, and in rare cases for more than a year, and severe symptoms may prevent a person from undertaking their usual activities.


Diagnosis can be difficult without the doctor taking a blood sample for laboratory testing as the symptoms are similar to those of a variety of other conditions.


Barmah Forest Virus Disease

The symptoms of Barmah Forest Virus disease are somewhat similar to those of Ross River Virus disease. However, some evidence suggests that in some cases the symptoms are less severe.


Australian Arboencephalitis

Early symptoms include:

         Sudden onset of fever.

         Frontal headache.

         Nausea and vomiting.


         Muscular aches.

         Intolerance of light (photophobia).


Encephalitis (inflammation of the brain) may occur between two and nine days after onset of early symptoms, so you must see a doctor if early symptoms occur.



As with many viral illnesses, there is no vaccine available or specific cure against these diseases. Therefore, it is essential that you take precautions to prevent being bitten by mosquitoes.


Should Ross River Virus disease or Barmah Forest Virus disease be diagnosed, the doctor will usually recommend rest and medication to relieve muscle and joint pain.


For Australian Arboencephalitis, the medical treatment will depend upon the nature and severity of the disease.


Precautions Against Mosquito-Born Disease

There are simple measures you can take to protect yourself and your family against mosquito-borne disease so you can enjoy the summer.


Some important measures are to:

         Remember, mosquitoes are more active at dusk and dawn.

         Wear long, loose clothing to cover up at dusk and dawn or when going near wetlands

or known breeding areas.

         Use a repellent such as N, N-Diethyl-M-Tolumide (DEET) Compound, preferably in a

cream or gel base. (See product for instructions on correct use).

         Use 'knockdown' sprays, coils and vaporising devices to kill mosquitoes.


Safety in the Great Outdoors

         In tents and caravans or the outdoors, use mosquito netting.

         Enhanced protection can be provided if you treat nets with a repellent/insecticide.

         If venturing into known mosquito breeding areas take steps to reduce the likelihood of

being bitten.


Reduce Mosquito Numbers Around Your Home

         Install and maintain flywire screens on all windows and doors (screens should be no

coarser than 12 x 12 meshes per 25 mm).

         As mosquitoes breed in water dispose of all tins, tyres and other rubbish which may

hold water and overturn boats and dinghies to prevent pooling of water.

         Regularly change the water in vases, pot plants, bird baths, pets' containers and any

other receptacles which hold water. Put sand around the bases of pot plants to absorb

excess water.

         Keep swimming pools chlorinated or salted, or empty them completely when not in use

for long periods.

Empty children's wading pools regularly.

         Prevent leaking taps and avoid over-watering lawns as this can lead to higher water

tables or run-off to storm water drains and create permanent pools.

         Flush unused toilets once a week.

         Keep drains and roof guttering in good repair and free of leaves and debris.

         Keep fish ponds stocked with fish.

         Ensure that tanks have close-fitting tops, lids, covers and inlet pipes to exclude

mosquitoes, and screen all water inlets and the outlet end of overflow pipes. As an

interim measure, treat water with a small amount of domestic kerosene or paraffin oil

(1-2 teaspoons to control larvae).




More Information

The Victorian Government Department of Human Services and local governments monitor mosquito-borne diseases across the State and conduct programs to help prevent disease. Current activities include:

         Surveillance of viruses and mosquitoes.

         Research to improve disease prediction and control.

         Development of a disease control plan.

         Advice on mosquito control measures.

         Awareness programs.


If you need more information on mosquitoes and mosquito-borne diseases, contact your local government health department or the Infectious Diseases Unit of Human Services on (03) 9637 4000.


Public Health Division , DHS , 1997

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