Chief Health Officer, Victoria, Australia

Health warning on mosquitoes - 22 February 2011

Residents and visitors along the Murray River in northern Victoria are being warned to protect themselves against mosquitoes following the detection of Murray Valley encephalitis virus (MVE) in the area.

Victoria’s Chief Health Officer Dr John Carnie said the disease has been detected in sentinel chickens at Mildura, Robinvale, Kerang, Barmah and Tooleybuc just across the border in New South Wales near Swan Hill.

No case of the disease has been detected in humans. The last human case of MVE in Victoria was reported in 1974 when a large outbreak occurred throughout much of south eastern Australia.

Following the 1974 outbreak, flocks of chickens were placed at locations throughout the Murray River region to act as an early warning system for possible human infections with this disease.

Currently there are 13 flocks along the Murray and in rural areas of Victoria.

What are the symptoms of Murray Valley encephalitis virus?

Typical disease symptoms include:

• severe headache
• high fever
• drowsiness
• tremor and seizures.

People experiencing such symptoms should seek urgent medical attention from their GP or their local hospital.

How to protect against mosquitoes

Traditionally mosquitoes are at their most active at dawn and dusk. However, with the extensive flood waters in and around a number of towns mosquitoes are presently being seen throughout the day.

To reduce the chances of being bitten, people in mosquito-prone areas should:

• use insect repellents containing picaridin or DEET as an active ingredient on exposed skin areas when camping or engaging in any outdoor activity
• ensure that insect screens fitted to doors and windows are in good condition
• use mosquito coils or citronella candles in small outdoor protected areas
• wear long, loose-fitting clothing, preferably in light colours
• get rid of stagnant water around the home or campsites.

Mosquitoes will breed in anything that can hold water including old tyres, unused fish ponds and pot plant holders. As mosquitoes take about 10 days to breed, water containers should be emptied at least once a week.

For more information on Murray Valley encephalitis visit the Infectious Diseases Epidemiology and Surveillance site.

For more information on managing mosquitoes visit the Diseases section of the Infectious Diseases Epidemiology and Surveillance site.

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Health warning on mosquitoes - 22 February 2011