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Vector-Borne Diseases on the Rise: Protect Yourself With EWG’s Guide to Bug Repellents

EWG Tips
Thursday, July 25, 2019

Summer is the season for enjoying the outdoors, but as cases of diseases from mosquitoes, ticks and flea bites continue to rise, Americans must remain vigilant about protecting themselves by using an appropriate and effective bug repellent.

According to the Centers for Disease Control and Prevention, cases of bug-borne diseases tripled in the U.S. between 2004 and 2016, mostly from mosquito and tick bites. Lyme disease and West Nile virus continue to plague large swaths of the nation: In 2016 alone, more than 36,000 cases of Lyme disease and more than 2,000 cases of West Nile were reported. The agency also reported that nine new vector-borne diseases were reported in the U.S. during that period, including tick-borne Heartland and Bourbon viruses.

Bug repellents can provide protection, but how do you choose the right one? The EWG Guide to Bug Repellents can help.

We recommend choosing repellents with one of the following active ingredients, which offer adequate protection and have low toxicity concerns when used correctly:

  • Picaridin
  • DEET (less than 30 percent)
  • IR3535 (20 percent)

The Environmental Protection Agency maintains an online database and search tool that allows users to filter repellents by active ingredient and identify protection against specific pests.

Tick-borne diseases made up more than three-fourths of bug-borne illness cases between 2004 and 2016. Since then, they have continued to be a problem. Although still considered relatively rare, cases of Powassan infections have increased in recent years, the CDC has said, and have been reported in multiple East Coast and upper Midwest states; a recent death in New Jersey resulted from an infection caused by tick-spread Powassan virus. However, changing climate and temperature conditions continue to shift insect and tick habitats, increasing the risk in areas previously unaffected.

For hiking, camping or spending time in wooded and grassy areas inhabited by ticks, permethrin-treated clothing and gear may be a reasonable alternative to traditional bug repellent.

Technically, permethrin is not a bug repellent but rather an insecticide, killing pests upon contact. Some studies show it offers protection against tick bites that is superior to traditional repellents; however, it is much less effect against mosquitoes.

The CDC recommends clothing and gear treated with 0.5 percent permethrin to prevent tick bites. However, it is neurotoxic and has been classified by the EPA as a likely human carcinogen.

Only a few published studies have investigated absorption rates of permethrin through the skin, and more research is needed to determine the health hazards associated with exposure through this route. If you choose permethrin-treated clothing, use them with caution, read labels and wash all treated clothing separately.   

If you and your family are traveling outside of the U.S. this summer, beware of the risk of exposure to diseases such as dengue fever, malaria, chikungunya and Zika. For up-to-date information about potential exposures and travel information for more vulnerable groups, such as children and pregnant women, visit the CDC’s travelers’ health website.  

Other ways to avoid bug-related problems:

  • Avoid products that combine sunscreen and insect repellent. These must be applied more frequently for adequate sun protection, increasing exposure to chemicals in the repellent.
  • Decrease the risk of inhalation by choosing lotion, pump or towelette repellents.
  • Reduce skin exposure by wearing long pants, long sleeves and socks, and by tucking in clothes.
  • Pregnant women should not use oil of lemon eucalyptus or para-menthane-3,8-diol, also known as PMD.
  • Do not use repellents on babies under six months old. Do not use oil of lemon eucalyptus or PMD on children less than three years old
  • Make sure to apply permethrin sprays in a well-ventilated area and away from children and pets, since children are often more susceptible to toxins than adults and permethrin is highly toxic to cats.

For more information on top repellent choices, products to avoid and vector-borne illnesses, visit EWG’s Guide to Bug Repellents.


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