Protecting Yourself from Tick-Borne Diseases

Ed Brandt and Candace Brassard - Office of Pesticide Programs, EPA

Tick Bite and Lyme Disease Prevention Advice from the EPA

 

There are hundreds of tick species in the world that are capable of transmitting pathogens.  The pathogens transmitted by such tick species cause over 65 diseases, many of them serious. While Lyme disease and Rocky Mountain spotted fever are the most well known of the tick-borne diseases, other diseases include Colorado tick fever, Anaplasmosis, Ehrlichiosis, Southern tick-associated rash illness, Tickborne relapsing fever and Tularemia. Thus, ticks are considered to be a significant public health pest. The increased occurrence of Lyme disease, as well as other tick borne diseases, is raising awareness and concern about the impact of these diseases on public health.

Who's at risk?

Lyme disease historically affects people of two very different age groups. Children (5-9 years old) are at highest risk (boys more than girls), followed by older adults (60-70 years old). Reported cases peak in June and July. Spring is the season of highest risk because immature ticks are active, extremely small (the size of a poppy seed) and hard to find.  People are exposed to ticks through typical outdoor activities including hiking, playing games, golfing, horseback riding and even gardening.

An ounce of prevention

It is important to know about tick habitats and personal protection techniques because most people are exposed to ticks in residential areas. Here are a few ways to prevent ticks:

1. Keep the lawn mowed to make your property unattractive to ticks. Ticks are found in high grass, yards with trees and shrubs.

2. Keep backyard grasses set back from the woods around a home by eight feet. Place a three-foot wood chip, gravel or mulch border area between grassy edges and tick-prone zones. Ticks prefer moist areas like leaf litter and the edge of woods. Ticks don't like the sun and wait in shady areas on brush and grasses.

3. Practice personal protection. Personal protection involves using repellents, wearing appropriate clothing and checking for ticks on one's person, which is the most effective practice of all. In tick habitats, wear long, light-colored pants tucked into socks or boots, and long-sleeved shirts. This keeps ticks from reaching the skin and makes them easier to see. Ticks like places on humans that are warm and moist, most commonly the backs of the knees, armpits, the groin, the scalp, the back of the neck, and behind the ears. Attached ticks should be removed as soon as possible using fine-point tweezers since risk of disease transmission is increased the longer the tick is attached.

High risk areas for Lyme disease

The Blacklegged tick (also called the Deer tick) is found throughout the United States. The Yale School of Public Health published a map that shows a clear risk of Lyme disease across much of the Northeast, from Maine to northern Virginia. It also identifies a high-risk region in the upper Midwest (particularly in Minnesota and Wisconsin).

Why tick populations expand

Ticks can move over long distances by attaching to migrating birds. When they detach in the new location, they colonize the local area, feeding on deer, mice, squirrels and chipmunks.

Climate and the location of hosts determine where ticks thrive. If average temperatures continue to increase over the coming decades, the areas where ticks live will continue to expand northward. In the 1990s, blacklegged ticks were virtually unknown in Canada, but today they are sometimes found in large numbers. Suburbanization has increased deer densities by breaking up forests and reducing hunting. Loss of biodiversity has also been correlated to increased presence of tick hosts and infected ticks. 

Predicting tick outbreaks

Predicting tick outbreaks is still an emerging science.  University of Rhode Island entomologist Thomas Mather says that high humidity this June may lead to more ticks, more bites and more cases of Lyme disease. If the humidity is low, ticks dry out and die, reducing the threat. (TickEncounter Resource Center).

Experts such as Richard Ostfeld with the Cary Institute of Ecosystem Studies are concerned that this spring may bring a "significant increase" in the number of cases of Lyme disease in the New York area. Looking at a cause-and-effect timeline from the past few years, the bumper crop of acorns in 2010 led to a bumper year for mice in 2011. Mice are a primary host for ticks.  In 2011, however, lower acorn counts meant fewer mice for 2012. Thus, the ticks will look for other hosts, including people.  Additionally, this year's mild winter temperatures mean an early arrival in tick activity. It should be noted, though, that caution and awareness are important during any year.

Early warning systems are being developed that include but are not limited to: 1) field monitoring by governmental agencies; 2) pet data reported by veterinarians; and 3) collection stations for deer hunters

Additional Resources:

CDC tick and tick-borne disease information

Using Insect Repellents Safely

Parasite Prevalence maps for tick borne diseases in dogs and cats

Managing Ticks and Preventing Tick Bites

 

About the Authors:

Ed Brandt: A statistician and economist, Ed is the former leader of the landscaping and structural pest sectors in EPA's Pesticide Environmental Stewardship Program (PESP) within the Biopesticides and Pollution Prevention Division, Office of Pesticide Programs. He led the PESP program promoting IPM to reduce Tick Borne Diseases the past 5 years, working with federal and state agencies as well as non-profit organizations.

Candace Brassard: As a senior biologist for the Field and External Affairs Division, Office of Pesticide Programs,Candy leads two working groups for federal and state and agencies as well as non-profit organizations. The goal of the working groups is to continue to promote IPM to reduce Tick Borne Diseases.

Candy and Ed have partnered for the past 5 years, resulting in a 25 member network, a federal partnership with 9 agencies, and a Tick Conference in March 2011.

The views presented in this article are the views of the authors and do not necessarily represent the views of the U.S. Environmental Protection Agency or the United States.