Insect Avoidance Measures
Insect bites are an extremely annoying and unpleasant part of life and an important cause of disease around the world. These are of particular relevance to travellers and residents in tropical or semi-tropical locations, and are important to both the urban and rural areas.
Malaria is the most well known mosquito-borne disease, however there are many other conditions of concern worldwide including Dengue Fever, Yellow fever, Japanese Encephalitis, and Ross River Fever. There are a number of other infections, which can be caused by flies, ticks and lice which are also commonplace.
There are vaccines which protect against some of the above illnesses, and there are some drugs which may have a protective effect also. However these measures will not give full protection against all of the insect borne illnesses. The recent increase in resistant Malaria strains means that the traveller or resident cannot solely rely on medication.
Hence, avoiding being bitten in the first place is the most important step in avoiding illnesses.
Ways of minimising your exposure to mosquito and other insect bites are to:
- Cover up
- Wear protective clothing covering arms and legs to reduce the amount of skin exposure.
- Decrease your attraction: Mosquitoes are attracted to dark colours and strong scents, so wear light colours and avoid perfumes and after-shave.
- Use Screens: Make sure you have well screened accommodation. Spray indoors with insecticide aerosols. Consider mosquito coils for balconies or poorly screened accommodation. Mosquito nets are cheap, effective and are especially useful when travelling.
- Protect bare skin: Use repellents containing DEET as this repels mosquitos, ticks and sandflies too, all which may carry diseases. Adequate strength of DEET is necessary. IMC stocks DEET based insect repellent – please enquire.
- Use Permethrin: This is a contact insecticide that can be used on mats etc. around the home. It can be used on bedding and clothing when travelling (see opposite).
- Avoid being a breeder: You can reduce potential breeding grounds around your home. Mosquitoes breed in stagnant water and do not travel long distances, so check for water in the base of pot plants, drains, old tyres etc.
The local authorities may also spray areas (known as ‘fogging’) to kill mosquito larvae. Stringent measures to prevent insect contact significantly reduce the risk of contracting disease. It is estimated, for example, that the risk of malaria is decreased by 90% with the above listed measures. This is particularly relevant when travelling to areas with a high likelihood of exposure. Further advice on these measures can be discussed with your family doctor.
Permethrin is a synthetic compound which has contact insecticide properties. So when an insect has contact with the substance, it will die. It does not have repellent properties, is odourless, non-staining and comes in liquid and powder form.
Permethrin adheres to cotton and fabric, and is widely used throughout the world as a treatment for sheets, mats and nets as an insect avoidance measure. This is of particular importance to travellers or residents in areas where insect borne illnesses are common. It is available in concentrated solution form, which can be easily diluted in water to treat fabric after it has been washed.
It will stay on clothing for 5 washes without loss of effectiveness. The solution is non-toxic to people, however it is best not to apply undiluted solution to skin and hence the use of gloves is recommended. It is biodegradable and should be disposed of in the normal refuse. The solution is available at International Medical Clinic and comes with more specific directions regarding usage and application.
Permethrin solution is widely used as a major defence against insect borne illnesses and is used widely by Governments, Defence forces, etc. When used in conjunction with repellents such as RID it is an extremely useful aid to the traveller or resident as a preventative measure.
- The U.S. EPA has determined that when label instructions are followed, all concentrations of DEET repellents can be used from age 2 months. However, the International Medical Clinic advises caution with babies below 6 months old.
- The benefits of DEET appear to plateau at a concentration of about 30%.
- The American Academy of Paediatrics recommends the maximum concentration of DEET for infants and children to be 30% and also that the lowest concentration for the expected amount of time spent outdoors be used.
- Only apply insect repellents to exposed skin taking care to avoid the eyes and mouth.
- Read the entire product label before using the repellent.
- Do not apply on wounds or scratches.
- Avoid over-saturation – it’s not necessary for adequate protection.
- Do not apply to the hands of small children, since they frequently put their hands into their mouths.
- Do not allow children to apply the product themselves.
- Cleanse the skin with soap and water after returning indoors.
- Keep out of the reach of children, because like many chemicals, DEET can be toxic if ingested.
- A very small percentage of children and adults may be sensitive to chemicals such as DEET. If there is a suspected reaction to an insect repellent, wash the area and seek medical attention.
IMC stocks DEET insect repellent at 2 strengths:
- 19% Adult preparation (RID ®)
- 7% – for children from age 2 months
However, children above the age of 6 months can use the adult strength preparation which reduces the frequency of reapplication. Reapplication is advised every 6hours for the adult strength and every 2 hours for the lower strength.