Insect Bite Prevention

Question

Our family is concerned that we practice the best prevention methods possible to protect our children and ourselves from malaria and other illnesses related to insect bites. What do you suggest we do in addition to taking malaria prophylaxis?

Answer

There are many biting insects but they do not all carry the risk for disease-the bite is simply a case of the insect protecting itself from you! Even the ones that bite out of self-protection can hurt enough to make you never want a repeat experience-like the fierce "army ant" found in Africa and other parts of the world!

However, it is critical to remember that disease transmission by mosquito and other insect bites is a major source of illness and death worldwide. According to the United Nations website detailing their efforts to eradicate malaria, one child in Africa dies of malaria every 30 seconds. Even with drug prevention, travelers are still at risk for malaria. Dengue fever, for which there is no preventive vaccine or drug, is a major cause for hospitalization in many tropical countries. Other insects that transmit disease are the tsetse fly, sand fly, black fly, mites, fleas and ticks. Preventing bites is vital to minimizing the risk of disease. Here are some key steps to remember:

  • Avoid infected habitats whenever possible; be aware of seasonal transmission patterns; avoid outdoor activity during periods when mosquitoes are active, for example, twilight periods at dawn and dusk. If camping, stay in areas that are high, dry, open, and free of vegetation, avoiding areas of standing or stagnant water.
  • Wear protective clothing such as long-sleeved shirts made of tightly woven fabric, socks, full-length pants and a hat. Tuck pant legs into socks or boots to prevent bites around the ankle area. Shirts should be loose fitting, worn over a t-shirt and tucked in to prevent bites to the upper body. Clothing should be light-colored to prevent attracting insects as well as to help to see insects that crawl or land on clothes. Hats should be light-colored with broad brims to prevent bites to the head and neck.
  • Use mosquito bed nets and mesh shelters; never question the use of nets in areas of high risk for malaria.

No serious illness has arisen from DEET when used according to the manufacturer's recommendations. Adults and children older than two months of age are recommended to use a repellant with concentrations of DEET as high as 50%.

Use an insect repellant that contains DEET

  • Apply the repellant to all exposed skin as well as on clothing (do not apply to skin that is covered with clothing). Heavy application is not necessary; if applied to clothing, wash treated clothing before wearing it again (if possible).
  • Do not apply repellant to cuts, wounds or irritated skin.
  • After returning indoors, wash off the repellant with soap and water. Temperature, perspiration, water exposure and rubbing against clothing affect the length of protection afforded by the DEET application. If in doubt, re-apply!
  • The more DEET a repellent contains, the longer time it can protect against bites. Seemingly, there is no added benefit with concentrations greater than 50%; lower concentrations offer short-term protection and require more frequent reapplication.

The use of insect repellant with children

  • No definitive studies have been published about what concentration of DEET is safe for children. No serious illness has arisen from DEET when used according to the manufacturer's recommendations. Adults and children older than two months of age are recommended to use a repellant with concentrations of DEET as high as 50%. Protect infants two months of age and less by using a carrier draped with mosquito netting with an elastic edge for a tight fit.
  • Application of DEET on a child: apply to your own hands and then rub them on the child, avoiding the eyes, mouth, and use sparingly around the ears - AVOID application to children's hands.

NOTE: studies show that non-DEET insect repellents cannot be relied on for prolonged protection from insect bites. A repellant with a concentration of 23.8% DEET had an average protection time of 5 hours compared to 1.5 hours for soybean-based repellants, and less than 20 minutes for all other botanical repellents tested. Repellent-impregnated wristbands offered no protection. (Fradin M.S; Day J.F. "Comparative Efficacy of Insect Repellents against Mosquito Bites," New England Journal of Medicine, 2002)