Biological Warfare--Protecting Yourself Against Insects

As one who leads safaris in Africa I often need to remind my clients that the most dangerous wild animal they will encounter is not the lion or the cape buffalo they view from the safety of their van. It is the mosquito which crawls into their bednet with them. Mosquito-borne diseases account for more annual deaths around the world than any other type of disease. Many of the routine preventive measures are beyond the means of the natives living in most tropical areas. But they are available to you.

Simple, physical protection is the most effective, the most ecologically sound, and the most often neglected. Mosquitoes simply cannot bite you if they cannot reach your skin. Even in the tropics one can comfortably wear long sleeves and long pants in the evening and early morning when mosquitoes attack and in the cool, dark areas where they like to live. At night in bed, one should sleep under a mosquito net, checking it before lights-out to make sure there are no mosquitoes inside it. (See our catalog.) A well-screened dwelling with local insecticides in sleeping areas will be almost as effective

The protective benefit of clothing and bednets can be further enhanced by impregnating them with Permethrin (see our catalog.) They can be soaked in this or it can be sprayed on. It is non-toxic to humans, does not damage fabrics and, once set, it will last through several months of washings. Adding Permethrin to bednets allows one to safely use a looser weave which allows more air circulation.

Insect repellents have long been the mainstay of insect protection. Of these, only DEET and picardin are of PROVEN benefit. DEET works by blocking the release of carbon dioxide from the skin, therefore it works only on treated areas of skin. And it works best at higher concentrations. In fact, concentrations of less than 20% are NOT of proven effectiveness. Because it is easily removed by washing or sweating, repeated applications are often necessary--unless one is using one of the long-acting forms such as Ultrathon or Sawyer Controlled-Release. These may be difficult to obtain (see our catalog) but are effective for 12 hours or more.

DEET has received an over-publicized bad reputation because of some cases of seizures in small children. Because of their thin skin and greater skin surface to body weight ratio, small children should not be treated with concentrations over 20% and not on the scalp (use a cap or hat instead.) Also, avoid repeated applications over a long time. When possible, it is best in the tropics to keep small children indoors after dark.

Some people with sensitive skin may develop rashes with DEET. For them, the physical measures mentioned above are of greater importance. Fortunately, one's attractiveness to mosquitoes depends a lot on individual body chemistry and some people are blessed with a chemistry which repels mosquitoes. Added to this, some of the lesser-proven repellents (Skin-So-Soft Citronella,) may be adequate protection. Mosquitoes ARE attracted, however, to many of the perfumes and scents which we humans also find attractive.