Mosquitos

In Australia mosquitoes are known to transmit a number of viruses that can cause human disease. The best way to prevent these diseases is by protecting yourself and your family from mosquito bites.

These diseases include:

• Ross River virus – find out more on Health Direct
• dengue fever
• Barmah Forest virus – find out more on Health Direct
• Murray Valley encephalitis
• Japanese encephalitis virus.

Prevention

To protect yourself against mosquito bites and reduce the risk of exposure to the diseases they may carry:

• cover-up with a loose-fitting long-sleeved shirt, long pants and covered shoes when outside
• apply mosquito repellent to exposed skin
• take special care during peak mosquito biting hours (in the ACT most mosquitoes become active at dawn and dusk, and into the evening)
• remove potential mosquito breeding sites from around the home
• screen windows and doors.

Wear appropriate clothing

Reduce the risk of mosquito bites by minimising the amount of exposed skin. Wear loose, light-coloured clothing with long sleeves, pants, socks and shoes.

Some mosquitoes will bite through clothing. Consider using clothing pre-treated with insecticides, for example permethrin, but remember that repellent must still be applied to exposed skin.

Apply mosquito repellent to exposed skin

The most effective mosquito repellents contain Diethyl Toluamide (DEET), Picaridin or para-menthane-3, 8-diol (PMD) also known as oil of lemon eucalyptus (OLE).

Use a mosquito repellent on all exposed skin areas. Reapply the repellent according to instructions or if you notice mosquitoes biting.

Avoid putting repellent near the eyes and mouth, or over open wounds, broken skin or abrasions. Always follow the product label instructions.

The strength of a repellent determines the duration of protection, with the higher concentrations providing longer periods of protection. Always check the label for reapplication times. Note that botanical-based products, such as eucalyptus or citronella, provide only limited protection and require frequent reapplication.

After swimming

Mosquito repellent needs to be reapplied after swimming. The duration of protection from repellent is also reduced with perspiration, such as during strenuous activity or hot weather, when it may need to be reapplied more frequently.

Sunscreen and repellent

If you are using sunscreen, apply the sunscreen first and then apply the repellent. Be aware that DEET-containing repellents may decrease the sun protection factor (SPF) of sunscreens so you may need to reapply the sunscreen more frequently.

Skin repellents for children, pregnant and breastfeeding people

Most skin repellents are safe for use on children aged 3 months and older, when used according to directions. Some formulations are only recommended for children aged 12 months and older. Always check the product label for recommended age use.

Infants aged less than 3 months can be protected from mosquitoes by using an infant carrier draped with mosquito netting that is secured along the edges.

Never allow young children to apply their own repellent.

Mosquito repellents registered in Australia and used according to product label instructions are considered safe for use during pregnancy and while breastfeeding.

Use appropriate insecticides

Aerosol insecticide sprays, mosquito coils (used outdoors) and insecticide vapour dispensing units (used indoors) can help to repel mosquitoes from an area. These products should be used in addition to, not in place of, other measures, such as appropriate clothing and skin repellents.

Alternative repellent products

New personal (e.g. clip-on) spatial repellent products containing active ingredients, such as metofluthrin, are likely to augment the effect of other measures but most have yet to be fully evaluated.

Devices that use light to attract and electrocute insects have not been proven to be effective in reducing mosquito numbers and often kill more harmless insects.

Be aware of the peak risk times for mosquito bites

Take extra care during peak mosquito biting hours to reduce the risk of infection. In the ACT and surrounding regions, most mosquitoes become active at dawn and dusk, and into the evening.

Use a mosquito net if you are sleeping outdoors if the area is known for mosquitos. Nets are most effective when they are treated with a pyrethroid insecticide such as permethrin. Pre-treated bed nets can be purchased, or nets can be treated after purchase.

Reduce mosquito risk around the home

Stop mosquitoes entering the home by using flyscreens on windows and doors, and screening chimneys, vents and other entrances. Regularly inspect screens and repair any damaged screens immediately.

Consider using a surface insecticide spray in areas where mosquitoes like to rest. During the day, mosquitoes rest and hide in cool shady areas such as in and around the home before emerging at dusk to feed. When using surface sprays, make sure you avoid aquariums and fish ponds, as fish are acutely sensitive to these insecticides.

Mosquitoes need water to breed and some mosquitoes can breed in very small amounts of water. To reduce the risk of mosquitoes breeding in around the home:

• clean up your backyard and remove all water-holding rubbish, including tyres and containers
• keep your lawns mowed
• empty and refill bird baths and water containers for pets at least once a week
• fill pot plant bases with sand to avoid standing water
• store anything that could catch and hold water undercover or in a dry place
• keep bins covered
• flush out water from the leaves of water-holding plants (such as bromeliads) once a week
• maintain roof gutters and remove leaves so that pools of water do not form.

Tanks and pools

Mosquitoes can also breed in containers or tanks used to store stormwater, greywater and rainwater. Tanks and containers should be either emptied, fitted with a well sealing lid, or have all openings covered with mosquito proof mesh. If mosquito larvae (‘wrigglers’) are present, then screen or close-off the point of entry. Do not allow water to pool in containers below the outlets or taps.

Properly cleaned and chlorinated swimming pools are rarely a source of mosquito breeding, but neglected pools can be a haven for mosquitoes. Ensure that pools are maintained with minimum disinfectant levels, cleaned regularly and serviced by filtration systems operating in accordance with manufacturer’s instructions.

Reduce mosquito risk around the farm

If you live on a farm, additional precautions are needed to reduce opportunities for mosquitoes to breed. These include:

• keeping dams and ground pools free of vegetation
• checking dam walls and irrigation bays for water leaks
• being careful not to over-irrigate to avoid water collecting in low-lying areas for long periods of time
• not allowing irrigation water to flow into and lie undisturbed in roadside table drains.