MOSQUITO CONTROL PROGRAM

What is the Shire of Capel doing? How Can You Assist? Ross River Virus Mosquito Monitoring Traps More Information

The majority of mosquito problems in the Shire of Capel are caused by the salt marsh mosquito - Ochlerotatus camptorhynchus. Mosquito breeding occurs in freshwater after periods of high rainfall where there is flooding of salt marshes. It is important to control the salt marsh mosquito as this mosquito is the main carrier of Ross River Virus and Barmah Forest virus.

Mosquitoes are known to present serious health risks and cause considerable nuisance to residents and visitors to the Shire of Capel. The 2003/2004 mosquito season saw an epidemic of Ross River virus throughout WA. In 2003/2004 there were 138 cases of Ross River virus notified from the Shire of Capel, in the second biggest outbreak on record in the south-west of WA.

What is the Shire of Capel doing?

The Shire of Capel has developed an extensive mosquito control program. The program involves larviciding to reduce the number of biting adult mosquitoes. Additionally mosquito monitoring traps are set up to assess the numbers of mosquitoes in an area.

How Can You Assist?

Mosquitoes breed in STANDING WATER. Standing water can be found in old tyres and other water holding containers, pot plant drip trays, septic and water tanks, roof gutters, domestic ponds, etc. By eliminating these breeding sites you can help to reduce mosquito numbers in your backyard.

You can help eliminate breeding in your backyard:

• Dispose of all containers which hold water.
• Keep ornamental ponds stocked with mosquito-eating fish, e.g. goldfish.
• Empty pot plant drip trays once a week or fill with sand.
• Empty and clean animal and pet drinking water once a week.
• Keep swimming pools well chlorinated and filtered and free of dead leaves.
• Fill or drain depressions in the ground that hold water.
• Prevent leaking taps which can maintain semi-permanent pools.
• Avoid over watering lawns. This can lead to high water tables or run off to storm water drains and create permanent pools.
• Vent pipes on septic tank systems must be fitted with mosquito proof cowls. Seal all gaps in the lid, and ensure leach drains are completely covered.
• Screen rainwater tanks and/or add paraffin oil to cover surface.
• Ensure roof guttering does not hold water.
• Some plants (especially bromeliads) hold water in their leaf axils. These should be emptied of water once a week.

Ross River Virus

What is Ross River Virus?

Ross River Virus (RRV) is a mosquito-borne virus found naturally in Australia. In nature the virus is passed between mosquitoes and wildlife. Kangaroos and wallabies in particular are commonly found infected with the virus.

Humans bitten by an infected mosquito may develop a disease called Epidemic Polyarthritis which is commonly known as 'Ross River virus disease'.

Correct diagnosis of the disease can only be cinfirmed by blood test.

Transmission of Ross River Virus and Barmah Forest Virus

Humans and other animals are infected by RRV and BRV after being bitten by a mosquito carrying the virus. Mosquitoes pick up the virus from infected animals. Some species of mosquitoes may short-cut this cycle by passing the virus through their eggs to subsequent mosquito generations.

Humans infected by RRV and BRV may pass the virus back to mosquitoes if they are bitten during the last few days of the incubation period and for several days following onset of symptoms.

In the Shire of Capel, the virus is thought to be principally spread by the salt marsh mosquito Ochlerotatus camptorhynchus.

Ross River Virus and Barmah Forest virus transmission occurs when temperatures are warm enough for the virus to be active combined with high numbers of mosquito carriers following rainfall.

Symptoms Of Ross River Virus and Barmah Infection

The incubation period of Ross River Virus infection varies from three days to three weeks, but symptoms usually appear within seven to fourteen days of being bitten.

People infected by Ross River Virus may develop a wide range of symptoms. Many people infected with Ross River Virus will not develop any noticeable symptoms, those that do may include: painful or swollen joints, sore muscles, skin rash, fever, fatigue, headache, dizziness, swollen lymph nodes, nausea and a general feeling of being unwell.

Fever, nausea and skin rash usually disappear within the first two weeks of illness. Joint and muscle pain, lingering fatigue and depression may last much longer in some individuals.

Many people with Ross River Virus disease will still feel unwell at three months and up to a quarter of sufferers will still have some symptoms after a year.

Treatment Of Ross River Virus Infection

There is no medical cure for Ross River Virus infection. Medical treatment is aimed at easing joint pains and swelling and minimising fatigue and lethargy. Aspirin appears useful to many sufferers in reducing pain and inflammation. Rest is very important for Ross River Virus disease sufferers, particularly during the early stages of the disease.

Stress, physical fatigue and alcohol may cause symptoms to worsen and prolong the duration of the illness.

Avoid Being Bitten

Steps to take to avoid being bitten by mosquitoes:

• Mosquitoes are most active during dawn and dusk. Try to avoid being outside during these times;
• Ensuring insect screens on houses are installed and completely mosquito-proof. If camping, use mosquito nets and mosquito-proof tents;
• Wearing long, light coloured, loose-fitting protective clothing when outdoors in mosquito-prone areas, (mosquitoes can bite through tight clothing);
• Apply personal repellents containing DEET (diethyl toluamide) or picaridin to all areas of exposed skin. The most effective and long-lasting formulations are lotions or gels. Most natural or organic repellents are not as effective as DEET or picaridin;
• Ensuring infants and children are adequately protected against mosquito bites, preferably with suitable clothing, bed nets or other forms of insect screening. Only infant-strength repellents should be used on children;
• In outdoor entertainment areas use products such as mosquito coils and citronella to repel mosquitoes. These are available at supermarkets and hardware stores. Electronic Bug Zappers are also available from hardware stores and are an effective device that use a ultra-voilet light to attract mozzies then kills them with an electric charge.
• Recognise and avoid areas of mosquito activity, eg. swamps, wetlands, salt marshes and billabongs; and
• Turn off the front lights to your house. Many mosquitoes are attracted to light.

How can I treat my mosquito bites?

Mosquito bites can be treated with the following products:

• Stingoes
• Meidcreme
• Dermocaine
• Paraderm Creme
• Tea Tree Oil
• Eucalyptus Oil
• Aloe Vera Gel
• Ice
• Methylated Spirits

More Information

Shire of Capel Mosquito Management Strategy

Major mosquito breeding sites in the Shire of Capel

Larviciding

MSDS Prosand

Mosquito Monitoring Traps

Adult mosquito traps are used to monitor the numbers and types (species) of adult mosquitoes found in certain areas.

This information is valuable to the Shire of Capel's Mosquito Control Program. Areas with large mosquito populations or those where disease carrying mosquitoes have been identified can be given priority and resources targeted to problem areas.

The University of Western Australia traps adult mosquitoes at the three major breeding zones and determines the species present and the number of mosquitoes carrying Ross River Virus found in the traps at each location.