Roger S. Nasci, Emily Zielinski-Gutierrez, Robert A. Wirtz, William G. Brogdon

Vaccines or chemoprophylactic drugs are available to protect against some vectorborne diseases such as yellow fever and malaria; however, travel health practitioners should advise travelers to use repellents and other general protective measures against biting arthropods. The effectiveness of malaria chemoprophylaxis is variable, depending on patterns of drug resistance, bioavailability, and compliance with medication, and no similar preventive measures exist for other mosquitoborne diseases such as dengue, chikungunya, or West Nile virus.

The Environmental Protection Agency (EPA) regulates repellent products in the United States. CDC recommends that consumers use repellent products that have been registered by EPA. EPA registration indicates the materials have been reviewed and approved for both efficacy and human safety when applied according to the instructions on the label.

GENERAL PROTECTIVE MEASURES

Avoid outbreaks. To the extent possible, travelers should avoid known foci of epidemic disease transmission. The CDC website provides updates on regional disease transmission patterns and outbreaks (www.cdc.gov/travel).

Be aware of peak exposure times and places. Exposure to arthropod bites may be reduced if travelers modify their patterns or locations of activity. Although mosquitoes may bite at any time of day, peak biting activity for vectors of some diseases (such as dengue and chikungunya) is during daylight hours. Vectors of other diseases (such as malaria) are most active in twilight periods (dawn and dusk) or in the evening after dark. Avoiding the outdoors or taking preventive actions (such as using repellent) during peak biting hours may reduce risk. Place also matters; ticks and chiggers are often found in grasses and other vegetated areas. Local health officials or guides may be able to point out areas with increased arthropod activity.

Wear appropriate clothing. Travelers can minimize areas of exposed skin by wearing long-sleeved shirts, long pants, boots, and hats. Tucking in shirts, tucking pants into socks, and wearing closed shoes instead of sandals may reduce risk. Repellents or insecticides, such as permethrin, can be applied to clothing and gear for added protection. (Additional information on clothing is below.)

Check for ticks. Travelers should inspect themselves and their clothing for ticks during outdoor activity and at the end of the day. Prompt removal of attached ticks can prevent some infections. Showering within 2 hours of being in a tick-infested area reduces the risk of some tickborne diseases.

Bed nets. When accommodations are not adequately screened or air conditioned, bed nets are essential in providing protection and reducing discomfort caused by biting insects. If bed nets do not reach the floor, they should be tucked under mattresses. Bed nets are most effective when they are treated with a pyrethroid insecticide. Pretreated, long-lasting bed nets can be purchased before traveling, or nets can be treated after purchase. Effective, treated nets may also be available in destination countries. Nets treated with a pyrethroid insecticide will be effective for several months if they are not washed. Long-lasting pretreated nets may be effective for much longer.

Insecticides and spatial repellents. More spatial repellent products are becoming commercially available. These products, containing active ingredients such as metofluthrin and allethrin, augment aerosol insecticide sprays, vaporizing mats, and mosquito coils that have been available for some time. Such products can help to clear rooms or areas of mosquitoes (spray aerosols) or repel mosquitoes from a circumscribed area (coils, spatial repellents). Although many of these products appear to have repellent or insecticidal activity under particular conditions, they have not yet been adequately evaluated in peer-reviewed studies for their efficacy in preventing vectorborne disease. Travelers should supplement the use of these products with repellent on skin or clothing and using bed nets in areas where vectorborne diseases are a risk or biting arthropods are noted. Since some products available internationally may contain pesticides that are not registered in the United States, it may be preferable for travelers to bring their own. Insecticides and repellent products should always be used with caution, avoiding direct inhalation of spray or smoke.

Optimum protection can be provided by applying the repellents described in the following sections to clothing and to exposed skin (Box 2-03).

REPELLENTS FOR USE ON SKIN AND CLOTHING

CDC has evaluated information published in peer-reviewed scientific literature and data available from EPA to identify several types of EPA-registered products that provide repellent activity sufficient to help people reduce the bites of disease-carrying mosquitoes. Products containing the following active ingredients typically provide reasonably long-lasting protection:

• DEET (chemical name: N,N-diethyl-m-toluamide or N,N-diethyl-3-methyl-benzamide). Products containing DEET include, but are not limited to, Off!, Cutter, Sawyer, and Ultrathon.
• Picaridin (KBR 3023 [Bayrepel] and icaridin outside the United States; chemical name: 2-(2-hydroxyethyl)-1-piperidinecarboxylic acid 1-methylpropyl ester). Products containing picaridin include, but are not limited to, Cutter Advanced, Skin So Soft Bug Guard Plus, and Autan (outside the United States).
• Oil of lemon eucalyptus (OLE) or PMD (chemical name: para-menthane-3,8-diol), the synthesized version of OLE. Products containing OLE and PMD include, but are not limited to, Repel and Off! Botanicals. This recommendation refers to EPA-registered repellent products containing the active ingredient OLE (or PMD). “Pure” oil of lemon eucalyptus (essential oil not formulated as a repellent) is not recommended; it has not undergone similar, validated testing for safety and efficacy, is not registered with EPA as an insect repellent, and is not covered by this recommendation.
• IR3535 (chemical name: 3-[N-butyl-N-acetyl]-aminopropionic acid, ethyl ester). Products containing IR3535 include, but are not limited to, Skin So Soft Bug Guard Plus Expedition and SkinSmart.

EPA characterizes the active ingredients DEET and picaridin as “conventional repellents” and OLE, PMD, and IR3535 as “biopesticide repellents,” which are either derived from or are synthetic versions of natural materials.

 Read the rest of the article at the Center for Disease Control

Source: CDC