Mosquito Avoidance Measures

Mosquito-borne and insect-borne diseases pose a significant threat to travellers, especially those who are considering a long-term stay in a mosquito-prevalent or endemic area.

It is important to be aware of which mosquitos are prevalent and follow proven bite-avoidance measures – it only takes one bite from an infected mosquito to lead to serious illness.

Traveller's should be aware of the mosquito-borne illnesses in your area of travel.

Vaccines can be used to reduce the risk of serious disease in a few instances. These include yellow fever, japanese encephalitis and dengue fever (new and only available in restricted circumstances). In some instances, vaccination (yellow fever) is required to enter certain countries.

Medication has been used for many years to reduce the risk of malaria (malaria chemoprophylaxis).

However, many most mosquito-borne viruses cannot be protected using vaccines or medication. Once infected, treatment is often difficult and only supportive measures are available. In other words, the disease must run its own course.

It is important to be vigilant and use prevention measures where appropriate. Breeding sites for mosquitoes only require a small volume of water; empty cans, coconut shells, pot plants saucers, buckets, vases etc. Squatter settlements and unplanned peripheral city areas promote breeding sites, particularly when local public health measures fail to keep pace with the expansion.

If you are in areas with many obvious breeding sites, then mosquito avoidance measures become very important.

Not all mosquitoes display the same behaviour, it is important to be aware of what mosquitoes are in your area of travel and consider your protection at times of risk.

Mosquito-borne diseases are best avoided via methods of bite-prevention. 

• Reduce exposure time by modifying activities, the Aedes aegypti is active during the daytime.
• Wear light-coloured clothing, and cover arms and legs as much as possible.
• Permethrin impregnation of clothing and bedding may be useful if there are a high prevalence of mosquitoes in your accommodation.
• Avoid highly scented perfumes, deodorants or toiletries.
• If possible, sleep under mosquito nets (preferably impregnated with permethrin) and if available, take advantage of ceiling fans and air-conditioning.
• Remove any potential breeding sites from around your accommodation (any small volume of water can be used as a breeding site: e.g. empty cans, coconut shells, discarded tyres, flowerpots, buckets).
• Use mosquito repellents on exposed skin (see table).
• Use insecticide aerosols, mosquito coils or other agents in the immediate environment.

The repellent of choice should contain DEET (N, N-diethyl-meta-toluamide). The higher the concentration of DEET, the longer the duration of protection.  However, there is no added benefit beyond 50% DEET concentration.  DEET is toxic when ingested and may cause skin irritation in some people.  If you have not used a DEET product before, or you have sensitive skin, it is advisable to test on a small area of skin before applying to larger areas of the body. 

DEET has been used over a long period of time, and by many millions of people with few reported serious side effects.  Despite this, a few precautions should be undertaken:

• Apply DEET lightly to exposed areas only.
• Where possible, wash off on returning indoors.
• Do not apply to open cuts or sores.
• Do not use aerosol applications to the face directly.  Apply to the hands and then rub on the face avoiding the eyes and mouth.
• Do not allow children <10 years to apply themselves.  Weaker DEET formulations (10% DEET concentration) are available for children.
• If sunscreens are to be used with repellents, then the sunscreen should be applied first.  Wait 20 minutes before applying repellent.

Picaridin, also known as Icaridin (1-piperidinecarboxylic acid 2-(2-hydroxyethyl)-1-methylpropylester), is a new alternative to DEET, and is a non-toxic, non-penetrative solution that is considered to be environmentally friendly and suitable for anyone 2 years and above. 

The recommended level of Picaridin is 20-25%, It lasts for around 4-6 hours before the need to reapply.  A 20% concentration of Picaridin is thought to be as effective as 20-30% of DEET.

Citronella only works for only a short period of time, perhaps around 20 minutes

Protection from other Australian plant products show very little protection apart from oil of lemon eucalyptus. It is weaker than DEET and Picaridin, lasting only about 2 hours. It should not be used on children under 3 years or applied to hands or around the mouth and eyes.

Permethrin, also known as Pyrethrum, is derived from the flowers of the Chrysanthemum, and is often used as a “knockdown” insecticide (not as a personal repellent). 

It is designed to damage the central nervous system of the insect that comes into contact, resulting in the immediate death of the insect.  The colourless, odourless solution is biodegradable and can be impregnated into fabrics (i.e. sheets, clothing, curtains, etc) and is effective against many insects, including mosquitoes, ticks, bedbugs, chiggers, scabies and flies. 

An impregnated net should be re-treated every 6 months, and fabrics will remain effective for between 5-10 washes.