Vol. 19 Issue 1, Spring 2014
by Alysoun Mahoney
If you love wildlife and the outdoors, you probably spend a lot of time in your yard, in parks, and in woods. And, you want to protect yourself from encountering black-legged ticks that may be infected with the Borrelia burgdorferi bacteria that cause Lyme disease. While it is not realistic to prevent tick encounters by managing every inch of every environment you may possibly visit, it is possible to prevent most tick bites by self-managing your own person.
Based on research, these are the most effective methods to safeguard against ticks:
- Personal tick checks and prompt removal: The definitive Tick Management Handbook states this is “probably the most important and effective method of preventing infection,” and multiple studies support this statement. The Centers for Disease Control recommends using a mirror to check under arms, in and around ears, inside the belly button, behind knees, between the legs, around the waist, and in hair. Ticks are hard to see—the nymph associated with the majority of Lyme disease cases is the size of a pinhead—so look carefully.
- Wearing protective clothing: Long pants and long sleeves help to keep ticks off your body. Light colors make it easier for you to spot ticks. A study of nearly 2,000 individuals found this method to be 40% effective in preventing Lyme disease.
- DEET on skin or clothing: The Tick Management Handbook states that when applied to clothes—especially shoe tops, socks, and the lower portion of pants—30% and 20% DEET are 92% and 86% effective against the black-legged tick, respectively, while skin applications are 75 to 87% effective. Note: The American Academy of Pediatrics recommends that DEET not be used on children younger than 2 months of age, that it be applied no more than one time per day for children older than two months, that products used on children have the lowest DEET concentration available, and that the product not be used on children’s hands or around their eyes and mouths.
- Permethrin-treated clothing: Two small-scale studies have found permethrin treatment to be highly effective in preventing tick bites, particularly when applied to shoes and socks. This is true for both commercially pre-treated clothing and do-at-home permethrin applications. An important caution is that permethrin should be applied to clothing only, never to skin. It should also never be applied to underwear, and permethrin-treated clothes should be washed separately from other clothing.
- Always read and follow all directions and precautions on product labels when using insect repellents.
For more information, see the Loudoun Wildlife Conservancy’s position paper Rebalancing Loudoun County’s Approach to Lyme Disease Mitigation.
In her seminal book, Silent Spring, Carson described a pesticide widely used in the 1950s against ticks and mites. She wrote, “What the public is asked to accept as ‘safe’ today may turn out tomorrow to be extremely dangerous.” The pesticide manufacturer had applied for a tolerance level that would sanction the presence of small residues on crops. Food and Drug Administration scientists had found evidence that the pesticide was carcinogenic and recommended zero tolerance. The manufacturer appealed, and the case was reviewed by a committee, which agreed to a compromise that allowed the pesticide to be used and tested for an additional two years. “Although the committee did not say so, its decision meant that the public was to act as guinea pigs, testing the suspected carcinogen along with the laboratory dogs and rats.” A total of three years passed before the pesticide was proved to be a carcinogen and ultimately removed from the market.
If Carson were alive today, what would she say about controlling ticks by spraying bifenthrin and other pyrethroids that are classified as possible human carcinogens?