INFORMATION SHEET

Mosquito-borne diseases

courtesy of Department of Health

Health warning -borne disease activity is environmentally driven. There is an increased The mosquito-borne diseases that are of risk in coastal areas following high tides, and concern in Western Australia are: in inland areas following heavy rainfall. Annual wet season activity • Ross River disease Murray Valley encephalitis and Kunjin • Barmah Forest virus disease virus diseases Activity in • Murray Valley encephalitis very wet seasons • Kunjin virus disease. Symptoms Rare activity after These diseases are caused by that • Fever extreme flooding are transmitted by the bite of an infected • Drowsiness mosquito. They cannot be caught by direct • Bad headache contact with another person or animal. • Stiff neck Note: Dengue fever and malaria are not • Nausea and vomiting currently transmitted in Western Australia. • Dizziness • Muscle tremors Ross River and Barmah Forest virus diseases Disease risk Murray Valley encephalitis risk areas

Symptoms The Department of Health advises people Reducing the risk living, working and travelling in northern • Painful and/or swollen joints Western Australia to take extra care to avoid There are no specific cures or vaccines for • Sore muscles mosquito bites due to the potential presence any of these mosquito-borne diseases so • Aching tendons of Murray Valley encephalitis and Kunjin it is very important that people take care to • Skin rashes viruses. The risk of infection with these prevent being bitten by mosquitoes and avoid • Fever viruses is low but symptoms can be severe. mosquito habitats where possible. • Tiredness Virus activity occurs annually in the Mosquitoes are most prevalent: • Headaches Kimberley region and during most wet • at dusk and night • Swollen lymph nodes seasons in the Pilbara. On rare occasions, it has been detected in the Gascoyne, Midwest • where there are large bodies of water Disease risk and northern parts of the Wheatbelt and • where there is stagnant water Goldfields regions after flooding events. • during warm weather. Cases of Ross River and Barmah Forest virus diseases occur across Western Australia. The Some seasonal weather patterns promote risk of virus transmission is generally highest mosquito activity and increase the risk. during spring and summer in southern regions of the State, and during the wet season in the north.

1 Controlling mosquitoes in most rural and • Ensure insect screens are installed and remote regions of Western Australia is completely mosquito-proof. Mosquito generally not possible because of the bed nets provide additional protection. large size and inaccessibility of the natural When camping, use mosquito-proof tents mosquito breeding habitat. However, the risk or cover swags with mosquito nets. of contracting mosquito-borne viruses can be • Adult mosquitoes are susceptible reduced by taking a few simple precautions. to desiccation (drying out) and are less active in windy conditions so, • Avoid outdoor exposure during periods where possible, locate camp sites or of greatest mosquito activity, which are accommodation villages away from generally one to three hours after sunset mosquito habitats, particularly locations and again around dawn. that may be very sheltered and the air is • Wear long, loose-fitting and light- likely to be still. coloured clothing to prevent mosquito • Ensure the drainage system at camp bites. sites or accommodation villages does not • Apply a personal insect repellent to allow water to accumulate and stagnate. exposed skin or clothing, and read the manufacturer’s instructions to determine the method and frequency of application. The most effective and long- lasting formulations are lotions or gels containing diethyl toluamide (DEET) at 5 to 20 per cent or Picaridin. Most natural or organic repellents are not as effective as DEET or Picaridin, and need to be reapplied more frequently.

Resources Safety Mosquito-Borne Disease Control Branch Department of Mines and Petroleum Department of Health 100 Plain Street PO Box 8172 EAST PERTH 6004 PERTH BUSINESS CENTRE 6849 Telephone: 08 9358 8002 Telephone: 08 9285 5500 Email: [email protected] Email: [email protected]

Issued 23 September 2014

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