[Health and Safety] Targeting Ticks

Editor's Note: In this excerpt from the 10th Edition of the Mallis Handbook of Pest Control, Dr. Jerome Goddard shares his insights about a common ectoparasite with serious health implications for the public. To learn more about the Mallis Handbook, visit www.mallishandbook.com.

Ticks are blood-sucking ectoparasites that cause significant skin lesions such as papules, nodules, and extensive secondarily infected areas of tissue. In addition to bite reactions, they are capable of transmitting a wide variety of disease organisms, such as protozoa (babesiosis), viruses (encephalitis and Colorado tick fever), and bacteria (Rocky Mountain spotted fever, ehrlichiosis, Lyme disease and tularemia).
 

Avoiding Tick Bites. The best way for pest management professionals to avoid contracting tick-borne diseases, such as Lyme disease, is to avoid tick bites. Avoiding tick-infested areas is the best approach, but if venturing into such areas is unavoidable, precautions should be taken. Long-sleeved shirts and long pants are a must when working or walking in tick-infested areas. Light-colored clothing should be worn to make ticks easier to see, and pants should be tucked into socks or boots to prevent ticks from crawling under pant legs. Tick repellents can be applied to the outside of clothing, particularly the pant legs.

After exiting infested areas, a visual body inspection should be made for ticks, and when working or walking in tick country, it is a good idea to conduct these examinations at least once a day. A favorite feeding site of ticks on human beings is at the base of the skull where long hair can hide the tick, so a co-worker should inspect the backside and back of the head. Remember, larval and nymphal stages of ticks are very small and may be overlooked as freckles. Clothing also should be washed immediately in warm water and detergent. Never throw such clothing in a hamper with other clothes or onto the floor. Pets need to be protected by preventing them from venturing into tick-infested areas.

Tick Control. The vectors and reservoir hosts of Lyme disease as well as a number of other diseases mentioned previously, ticks are creatures of the woods and fields. With the exception of the brown dog tick, it is not likely that other tick species will be found in large numbers inside the home, although the white-footed mouse does occasionally invade homes in the fall, especially in suburban areas. These ticks can be found in the yard and garden, however, and many cases of Lyme disease are contracted in suburban backyards.

Consequently, vector control performed by a competent commercial pest management professional is an important component of Lyme disease prevention. This is especially true for suburban residential premises bordering woodlots. Considerable reduction of numbers of both hosts and vectors can be realized through frequent mowing of grass and elimination of brush, weeds, leaf litter and other yard waste. Items which must be stored out-of-doors should be stored 12 to 18 inches off the ground and away from the structure, thereby limiting these as potential harborage sites.

The same insecticides useful in outside control of the brown dog tick also will be useful in the control of wood ticks; however, it should not be necessary to treat the inside of structures for these ticks. Commercial repellents are useful for application to a person's body and clothing when working in the yard and garden. Certainly the use of such repellents must be considered when venturing into fields, woods or along pathways in parks or in the country. Label directions for repellents must be followed closely because some repellents developed for use on bare skin may stain certain fabrics. Conversely, some repellents registered for use on clothing may cause dermatitis if placed on the skin. DEET-containing repellents will work against ticks, but permethrin-based products are more effective. One study demonstrated the efficacy of 0.5% permethrin, delivered from a pressurized aerosol dispenser onto clothing, as personal protection against the lone star tick, Amblyomma americanum (L.). Commercial preparations of 0.5% permethrin are widely sold under the brand name "Repel Permanone" or something similar.

The author, a medical entomologist, is a frequent editorial contributor to PCT and author of The Physician's Guide to Arthropods of Medical Importance.