In a recent letter to the Bangor Daily News (May 31), Valerie Rough suggested that reducing the white-tailed deer herd in Maine would reduce deer tick numbers and the potential for Lyme disease transmission to humans.
It has been demonstrated experimentally on a small island in Massachusetts that total elimination of the deer herd reduced deer tick numbers. However, elimination of deer is not a viable option in most areas. In addition, a partial reduction in deer density may not affect deer tick numbers, because deer ticks utilize many other warm-blooded animals, including humans.
In how many areas in Maine would a severe reduction of deer be acceptable to the public? Currently, the Maine Department of Inland Fisheries and Wildlife is bringing the Maine deer herd back from low population levels of the late 1970s and early 1980s. Severe reductions would go against current management plans developed with the input of a “public working group.” It should also be noted that in some areas of coastal Maine, deer hunting is prohibited or firearms discharge is regulated. Reductions of the deer herd through legal hunting could not be achieved in these areas.
White-footed mice are the primary source (reservoir) of the Lyme disease bacteria (Borrelia burgdorferi) found in deer ticks. The deer tick has a complex life cycle from larva, to nymph, and finally adult. Larvae and nymphs commonly attach to white-footed mice, as well as other hosts. If they feed on a mouse carrying the bacteria, they become infected and can pass the bacteria on to future hosts. Apparently, the white-tailed deer is not a reservoir for the disease.
Surveillance efforts in Maine indicate the deer tick is common in scattered coastal areas of York and Cumberland counties. It is occasionally found in other areas of Maine, particularly along the coast. However, only a low percentage of ticks carry the disease-causing bacteria.
Only a few cases of Lyme disease have been officially reported in Maine (in York and Cumberland counties). The disease is usually characterized by a circular rash, and perhaps flu-like symptoms occurring within a month of the tick bite. Early treatment is often very effective.
The immature deer tick may be difficult to see. The adult is black and red before feeding; after it is filled with blood it is blue-black in color.
Taking preventive measures is the best way of reducing your risk of contracting Lyme disease. While walking in the woods, brush or tall grass:
Wear socks pulled over long pants.
Wear long sleeves, hat and closed shoes or boots.
Use a commercial tick repellent on clothing.
Wear light-colored clothing.
On returning home:
Inspect your body, your children, and pets.
Search through the hair, around hairlines, behind ears, and around eyes.
Shower and inspect body folds.
Wash clothing immediately after an outing.
If a tick is found and it has penetrated the skin, use tweezers to grasp the tick at the skin surface. Pull slowly, gently to remove. Never squeeze or crush the tick. Put the tick in a jar of alcohol should a physician want to see it later. See your physician immediately if you suspect you may have Lyme disease.
If you live in an area with ticks, keep your lawn mowed and brush cut. Ticks climb on vegetation and attach to a host when it brushes against them.
The Maine Lyme Disease Task Force, comprised of state agency representatives and medical doctors, is monitoring the status of Lyme disease in Maine, conducting surveillance of deer ticks, and providing current information to doctors and the public.
Richard L. Dressler, Ph.D. is the cervid project leader with the Maine Department of Inland Fisheries and Wildlife, and a member of the Maine Lyme Disease Task Force.