Insects are a nuisance and may transmit several diseases like malaria, yellow fever and dengue fever.
Mosquito nets An impregnated bed net around the bed or sleeping place at night are the most efficient way of preventing malaria after taking regular prophylaxis as tablets. The effects are greatly enhanced by impregnating the net with a synthetic pyrethrum like permetrhine, deltamethrine or lambda-cyhalothrine.
The impregnation last from 6 to 12 months. If not used the shelf life may be prolonged by packing the net in a tight plastic bag.
The net must be so large that it can be tugged under the mattress and so big that it is not touched during sleep.
Correct use of an impregnated bed net at night reduces the risk of getting malaria by at least 50%.
Insect bites Insect bites are a nuisance and may transmit diseases like malaria, yellow fever, dengue fever, Japanese encephalitis and ticks transmit scrub typhus, central European encephalitis and borreliosis.
How to reduce insect bites?
wear clothes with long sleeves and long trousers, and avoid clothes in dark colours;
sleep in a room with screens covering the windows or with air-conditioning;
If the sleeping room is not air-conditioned or has no screens, use an impregnated bed net.
Smoke-coils. Coils, which burn during the night and are assumed to evaporate insecticide into the room can be bought in most tropical countries. The effect is doubtful and the method is not recommended.
Electric evaporator. The device contains a ceramic plate, which is heated by electricity. A tablet containing insecticide is placed on the plate and insecticide is released throughout the night if the tablet is fresh. The device is better than the burning spiral, but not as efficient as the bed net.
Wristbands. Several companies’ market wristbands im-pregnated with DEET and citronella oils. They have absolutely no effect no matter what impregnation.
RepellentsThere are several insect repellents on the market. The best known is based on DEET (Di-Ethyl-Toluamide) usually in a 20% solution.
The Eucalyptus extract p-menthane-3,8-diol, PMD, (marketed under the name of Quwenling or Mosi-guard) in a 50% preparation is equally effective as DEET.
There any many natural products based on for instance citronella and coco oils, but these are generally much less effective.
DEET 20% protects against mosquitoes for at least 4 hours and PMD 50% for the same time period. Citronella and related natural products can only be relied upon for minutes. All repellents may cause adverse reaction like allergic contact dermatitis and should not be used in the face and should not be used on children less than 3 years old.