Repel

There is no cure or vaccine for mosquito-borne disease in WA. The only way to prevent infection is to avoid being bitten, and the best defence you can have from a debilitating mosquito borne disease are your own personal protection measures:

avoiding known mosquito habitats (such as wetlands) and peak biting times (dusk),
wearing protective clothing
apply a suitable insect repellents.

Not all mosquito repellents are equal

A survey across 5 Bunbury and Busselton retailers found more than 50 different mosquito repellent formulations. So how can you tell which ones will work best?

Research has found those with the active ingredients of diethyltoluamide (DEET), picaridin or p-menthane-3,8-diol (PMD), also known as oil of lemon eucalyptus (OLE) tend to be most effective. And the higher the concentration the longer their effectiveness lasts.

DEET has been shown to be effective at preventing bites from a wide range of mosquito species including those that carry Ross River Virus and Barmah Forest Virus. It’s considered the Gold Standard in mosquito repellents. But the experts are still divided on exactly how DEET works. Many experts believe that it prevents bites by obstructing the mosquito’s ability to identify you as a target, but there is also some research that the mosquitoes smell, and are repelled, by DEET.

Picaridin works just as well as DEET, but many people find it preferable as it is odourless.

OLE is also known as PMD is an effective alternative. To read more about recommended repellents and products to be cautious of visit https://ww2.health.wa.gov.au/Articles/N_R/Personal-insect-repellents

Are DEET and Picaridin safe?

All topical insect repellents sold in Australia must be registered with the Australian Pesticides and Veterinary Medicines Authority (APVMA). The APVMA assess products for their efficacy and safety.

Repellents are considered extremely safe when applied correctly. With extremely widespread use DEET, and increasingly picaridin, over many years there are very few serious adverse reactions reported. As such, the two products have been endorsed by health authorities both here in Australia and internationally as a safest most effective way to avoid mosquito bites.

However, if you experience a serious reaction, consult your GP or call the Poison Information Centre Australia on 13 11 26

What’s the best repellent?

With so many products on the market it is easy to be confused when selecting the best mosquito repellent. The easiest way to tell the difference between two different repellents is to look at the concentration of the active ingredients (DEET,Picaridin, PMD or OLE). The greater the concentration of a repellent the longer they will keep working.

The concentration of the products does not affect its effectiveness at keeping mosquitoes that are kept at bay. Applied properly a 5% DEET product will work just as well as a 30% DEET concentration.

Repellents containing DEET at concentrations of 80% or 10%, for example, will both protect against mosquito bites for about two hours. While the protection provided by the 10% formulation may stop after a few hours, the 80% formulation will continue to provide protection for over ten hours.

When choosing a repellent, it’s worth keeping in mind just how long you’ll need to protect yourself. For a short run around the park, a low-concentration repellent will do the trick. But if you’re off to the beach for a long night fishing, a higher concentration repellent will keep working for hours on end.

Is Brand A better than Brand B and should I use a roll on or a spray?

Probably not. The choice of active ingredient is the most important decision. The choice of formulation is probably best guided by the ease of application. Sprays are generally most effective for arms and legs while creams and wipes are good for the face.

For complete protection, the entire surface of exposed skin must be covered. For this reason, it is probably best to apply repellent to your hands first, and then rub into exposed skin. A spray “here and there” won’t offer protection. Spraying repellent on clothes and/or belongings won’t help either.

What about ‘natural’ repellents?

Products derived from plants are often perceived to be a more natural alternative to the chemical products such as DEET and picaridin. Homemade concoctions of essential oils, particularly Eucalyptus and Melaleuca oils, are often promoted as the “safe alternative” to commercially available repellents.

Unfortunately, several studies have found that essential oils provide only limited protection from biting mosquitoes. Registered commercial products that contain botanical extracts offer some protection but will need to be reapplied far more frequently than even the low concentration DEET- or picaridin-based repellents.

Products containing OLE or PMD have recently been endorsed nationally as an effective alternative to DEET or Picaridin.

How about wrist bands, clickers, broaches and other new products?

Although patches or plastic wrist bands are registered as repellents by APVMA, these only offer very limited and localised protection (generally only immediately around the product, if at all).

Ultrasonic repellents have been sold in many forms for many years. The most recent incarnation is smartphone apps. The failure of sound to repel mosquitoes has been shown time and time again. They simply don’t work.

How to apply a Mosquito Repellent

Always apply the repellent according to the instructions on the label.

Always use a repellent containing up to 20% DEET, picaridin, OLE or PMD.
Where mosquito exposure is lengthy use of a >20% DEET may be more appropriate.
Apply repellent to all areas of exposed skin.
For all areas (except face), apply repellent directly to skin and spread evenly with hands.
For face application, apply first to hands and then spread evenly on face, avoiding the mouth and eyes.
Do not apply repellent under clothing.
For prolonged periods outdoors, you may need to reapply repellent. Follow label instructions about how often you need to do this.
Repellents will not work if you apply them sparingly to the skin.

Repellents are considered extremely safe when applied correctly. However, if you experience a serious reaction, consult your GP or call the Poison Information Centre Australia on 13 11 26.

Protecting your Children.

Where possible, avoid exposing your baby or child to mosquitoes. Consider staying indoors, using pram netting or dressing them in loose long-sleeved clothing, socks and shoes.

Under 12 months – repellents containing DEET or picaridin are not recommended.
From 12 months – repellents containing up to 10% DEET or picaridin can be used.

Applying mosquito repellent on children

Always apply the repellent according to the instructions on the label.
Do not allow children to apply repellents.
Apply repellent first to the hands of the carer and then spread evenly to exposed skin of child.
Avoid applying repellent to the child’s hands, near the eyes or mouth.
Avoid applying repellent under clothing.

Insect repellents

Insect repellents work by either blocking the cues that identify the wearer as a potential blood meal or providing an odour that overrides that of the your natural scent. There are a wide range
of repellents available, broadly categorized as either synthetic or botanical in nature.

Synthetic repellents

The most effective and widely used repellent internationally is DEET (diethyltoluamide). Developed by the United States Army in the 1950s, DEET is now used by many millions
of people around the world and is available in a wide range of application formulations (e.g. roll-ons, lotions, aerosols, pump-sprays and wipes) and concentrations.

Generally, repellents containing less than 10% DEET will offer up to two hours’ protection from mosquitoes. Repellents that contain up to 80% DEET are more suitable for long periods of exposure to mosquitoes in areas of endemic vector-borne disease.

Picaridin is another widely available active ingredient found in commercial insect repellents in Australia. This product was developed more recently, is generally thought to have a more pleasant scent than DEET and has lower toxicity to humans (making it more appropriate for use on children). Scientific studies have shown that this product is equally effective at
preventing insect bites as DEET.

Botanical repellents

plant-citronella There are a large number of plants whose essential oils or extracts may provide protection against biting insects. The most common products come from strongly aromatic plants, such as eucalyptus or teatree, and commercial products often contain a blend of extracts. Many scientific studies have compared botanical and synthetic repellents and, although botanical products may provide some protection, products such as DEET and picaridin provide substantially greater and longer term protection, even at low concentrations. Some natural products offer protection for only a few minutes, leaving users unprotected and exposed to disease-carrying vectors.

However, research on repellents with botanical-based active ingredients is continuing and these products may be useful under some circumstances.

Coils, sticks and other gadgets

Burning plant material to repel biting insects has been used by many cultures for thousands of years. Today, the tradition continues in the form of mosquito coils and sticks. The mosquito coil is the most popular form of personal protection from biting insects over the past 100 years. These devices are made of materials impregnated with insecticide (e.g. synthetic pyrethroids, such as allethrin) that burn slowly (some coils burn for up to eight hours) and may provide up to 80% protection. Some formulations are also available with botanical active ingredients, but these

are generally less effective. Coils are cheap to produce and easy to operate, although the smoke produced may present a health risk when used indoors. There is also a number of electronic units available (for both indoor and outdoor use) that release insecticides from slow-release mats or liquids. These units can be very effective, as the pyrethroids kill mosquitoes rather than
simply repelling them.

A wide range of products claim to repel biting insects in formulations other than topical repellents. Products containing synthetic or botanical active ingredients can include patches and wrist bands that claim to provide a degree of protection. However, scientific studies have shown that these products offer substantially less protection than topical repellents.

Repellent safety

All repellents used in Australia, whether synthetic or botanical, must by law be registered with the APVMA and the approval number must be listed on the label. There is often a perception that synthetic repellents, such as DEET, are unsafe. However, despite the widespread use of DEET-based products internationally, there are very few cases of adverse reactions. Most of these cases involve serious misuse, most commonly applying too much of the product (especially on young children), eating it or exposing the eyes to the product. Botanical-based products can
also cause irritation. The risk of an adverse reaction from using a repellent is very low and failing to use repellents in some locations will almost certainly result in insect bites and the real possibility of acquiring an infectious disease. Regardless of the active ingredient, all repellents should be applied according to the instructions on the label.

Treating mozzie bites

The classic “mozzie bite” is an itching, inflamed lump on the skin is an allergic reaction to the saliva injected by the mosquito during blood feeding. The severity of the reaction varies a lot between people, but your susceptibility to mosquito borne diseases like Ross River Virus, bears no relationship to the bite reaction.

If you are bitten the following treatments can help reduce the discomfort

Clean and dry the bite with warm soapy water and a clean cloth
Apply a cool compress (i.e. icepack wrapped in cloth)
The application of a medication lotion (e.g. anti-inflammatory, anti-puritic) or soothing substance (e.g. aloe vera) may reduce itchiness and the use of an antiseptic cream will prevent secondary infection. If secondary infection occurs, antibiotics may be required but consult a medical professional for specific advice.
Severe reactions may need to be treated with topical or oral antihistamines but consult a medical professional for specific advice on the most suitable medication.
Many home remedies exist for the treatment of mosquito bites. The application of a paste comprised of a mixture of baking/bi carb soda and water is thought to offer some relief from itching but there are no scientific studies to support this treatment.