bites insect


El Tigre Journeys

in the heart of the Amazon

Protection from Mosquitoes

and other Arthropod Disease Vectors

Although vaccines or chemoprophylactic drugs are available against important vector-borne diseases such as yellow fever and malaria, there are none for most other mosquito-borne diseases such as dengue, and travelers still should be advised to use repellents and other general protective measures against arthropods. The effectiveness of malaria chemoprophylaxis is variable, depending on patterns of resistance and compliance with medication. For many vector-borne diseases, no specific preventatives are available.

General preventive measures

The principal approach to prevention of vector-borne diseases is avoidance. Tick- and mite-borne infections characteristically are diseases of “place”; whenever possible, known foci of disease transmission should be avoided. Although many vector-borne infections can be prevented by avoiding rural locations, certain mosquito- and midge-borne arboviral and parasitic infections are transmitted seasonally, and simple changes in itinerary can greatly reduce risk for acquiring certain infections.

.Travelers should be advised that exposure to arthropod bites can be minimized by modifying patterns of activity or behavior. Some vector mosquitoes are most active in twilight periods at dawn and dusk or in the evening. Avoidance of outdoor activity during these periods can reduce risk of exposure. Wearing long-sleeved shirts, long pants, and hats will minimize areas of exposed skin. Shirts should be tucked in. Repellents applied to clothing, shoes, tents, mosquito nets, and other gear will enhance protection.

When exposure to ticks or biting insects is a possibility, travelers should be advised to tuck their pants into their socks and to wear boots, not sandals. Permethrin-based repellents applied as directed (see the following section, “Repellents”) will enhance protection. Travelers should be advised that, during outdoor activity and at the end of the day, they should inspect themselves and their clothing for ticks. Ticks are detected more easily on light-colored or white clothing. Prompt removal of attached ticks can prevent some infections.

When accommodations are not adequately screened or air conditioned, bed nets are essential to provide protection and comfort. Bed nets should be tucked under mattresses and can be sprayed with a repellent, such as permethrin. The permethrin will be effective for several months if the bed net is not washed. Aerosol insecticides and mosquito coils can help to clear rooms of mosquitoes; however, some coils contain dichlorodiphenyltrichloroethane (DDT) and should be used with caution.


Travelers should be advised that permethrin-containing repellents (such as Permanone®) are recommended for use on clothing, shoes, bed nets, and camping gear. Permethrin is highly effective as an insecticide and acaricide and as a repellent. Permethrin-treated clothing repels and kills ticks, mosquitoes, and other arthropods, and retains this effect after repeated laundering. There appears to be little potential for toxicity from permethrin-treated clothing. The insecticide should be reapplied after every five washings.

Permethrin-containing shampoo (Nix®) and cream (Elimite®), marketed for use against head lice and scabies infestations, potentially could be effective as repellents when applied on the hair and skin. However, they are approved only to treat existing conditions. Most authorities recommend repellents containing N,N-diethylmetatoluamide (DEET) as an active ingredient. DEET repels mosquitoes, ticks, and other arthropods when applied to the skin or clothing. Formulations containing <35% DEET are recommended because the additional gain in repellent effect with higher concentrations is not significant when weighed against the potential for toxicity. Travelers should be advised to use lower concentrations for children (no more than 10% DEET). Repellents with DEET should be used sparingly on children 2 through 6 years of age and not at all on infants younger than 2 years of age. A microencapsulated, sustained release formulation can have a longer period of activity than liquid formulations at the same concentrations. Length of protection also varies with ambient temperature, extent of perspiration, any water exposure, abrasive removal, and other factors.

DEET is toxic when ingested. High concentrations applied to skin can cause blistering. Rare cases of encephalopathy in children, some fatal, have been reported after cutaneous exposure. Other neurologic side effects also have been reported. Toxicity did not appear to be dose-related in many cases and these might have been idiosyncratic reactions in predisposed individuals. However, a dose-related effect leading to irritability and impaired concentration and memory has been reported.

Travelers should be advised that the possibility of adverse reactions to DEET will be minimized if they take the following precautions: (1) apply repellent sparingly and only to exposed skin or clothing; (2) avoid applying high-concentration products to the skin; (3) do not inhale or ingest repellents or get them in the eyes; (4) avoid applying repellents to portions of children’s hands that are likely to have contact with the eyes or mouth; (5) never use repellents on wounds or irritated skin; and (6) wash repellent-treated skin after coming indoors. If a reaction to insect repellent is suspected, travelers should be advised to wash treated skin and seek medical attention.

Bed nets, repellents containing DEET, and permethrin should be purchased before traveling and can be found in hardware, camping, sporting goods, and military surplus stores.

For more information about dengue fever, malaria, and other diseases mentioned on this page, see the Diseases

No vaccinations are required to enter Perú or visit the Peruvian Amazon

    El Tigre Journeys

    Educational and Adventure

    Travel Opportunities to Perú

    Based in Perú

    ~ El Tigre Journeys/Amazon SpiritQuest, Calle Nanay #145, Iquitos, Perú ~

    Contact Howard Lawler at (011-51-94) 22-3595

    United States Liaison

    ~ Sanchi Reta Lawler, P.O. Box 1704, Boulder, Colorado 80306+1704 ~

    (303) 442-8090 phone/fax/voice mail

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