Lyme disease has been known as a medically important illness since 1975 when many residents near Lyme, Connecticut, were mysteriously stricken. The disease is now known to be caused by a tick-borne bacterium (Borrelia burgdorferi). In the intervening years, Lyme disease has become an important tick-borne illness in North America.
The ticks that carry Lyme disease have expanded their range across the country. Cape Cod, Nantucket, Martha's Vineyard, Long Island, and Connecticut have experienced more cases of Lyme disease than most other areas of the Northeast, and are referred to as highly endemic areas for this disease.
The Lyme disease bacterium is carried by a tick commonly known as the deer tick or black-legged tick. It can pass the bacteria to a human or animal as it feeds upon them to obtain a blood meal. Deer ticks are active on Cape Cod year round, especially during years with mild winters.
Deer ticks have a three-stage life cycle. The adult tick is active in the late fall and early spring while the larvae and nymphs are active during the late spring, early summer and fall. The adult tick is a dark reddish brown and the size of a sesame seed. The nymphs are smaller, poppy seed sized, and are difficult to see. The larvae are extremely small, similar in size to a period. Any deer tick stage can be carried by dogs and cats, but the usual hosts are woodland mammals such as the while-tailed deer and while-footed mouse.
Adult ticks feed and mate on large mammals such as deer, pets, or humans in the fall and early spring. Female ticks drop off and lay eggs on the ground in the spring. Miniscule larvae hatch and feed upon white-footed mice, other small mammals or even birds. If the host mammal is infected with Lyme disease bacteria, then deer tick larvae will become infected. After feeding, larvae become inactive until early spring when they molt into the nymph stage.
Nymphs that have picked up the bacteria in the larval stage are capable of transmitting the bacteria to humans or other hosts, including pets. This stage is most active in June, and causes more cases of Lyme disease than the adult tick. Nymphs seek a host for a blood meal in the late spring and summer. The host may be a small mammal or bird, but may also be a dog, cat, or human. After feeding, nymphs molt into the adult stage. Adult ticks start the cycle over by feeding on a large mammal such as a deer, pet, or human. Note that both infected nymph and adult ticks can transmit the Lyme disease bacteria. These ticks may also transmit Babesiosis and Ehrlichiosis.
There are two common ticks found on Cape Cod and the Islands: the deer tick and the American dog tick. The American dog tick is larger than the deer tick and is more readily seen and easier to remove.
Note the relatively smaller size and teardrop shape. The dorsal shield is blackish; the abdomen is reddish-brown. The male tick is uniformly dark brown.
*(Not actual size.)
|American Dog Tick*
The dorsal shield is whitish; the abdomen is chestnut brown. The male tick is mottled gray.
*(Not actual size.)
The females of both species become engorged or greatly swollen during a blood meal. The color of the abdomen changes to a uniform gray.
Deer ticks are most often found in woodland habitats such as hiking trails, conservation lands and other forested recreational areas. They move onto brush, vegetation or tall grasses as they seek a host. They do not jump or fly but will crawl onto and cling to humans and animals that pass by. When walking in these types of areas, take the following precautions:
- Ticks are easier to see against a light colored background; wear light-colored clothing when in tick habitats.
- Wear long pants when walking in tall grass or brush, and tuck the pant legs into your socks.
- Keep to the middle of tails and avoid brushing against vegetation. Note that children may be especially at risk if they play in leaf litter where ticks may be waiting for a host.
- Check for ticks frequently while walking or working in tick habitats. Check your dogs as well if they accompany you.
- When walking or working in tick habitats, the use of a repellent is suggested. Products containing DEET (N-N-diethyl-metatoluamide) are suitable for adult use. Use with caution on children. Repellents may also be applied to clothing.
- Other products, such as permethrin, a contact insecticide, should only be applied to the outer clothing. Read and follow all label directions carefully.
- Use veterinarian-approved tick control products on pets that are allowed outdoors. Ask your veterinarian about Lyme vaccines.
- After hiking or walking outside, clothes may be heated in a dryer to kill hidden ticks.
- Keep brush and tall vegetation away from the house. Keep bird feeders at a distance as birds may carry ticks. Feed the birds only during the colder months of the year.
- Damminix™, a novel biodegradable management product aimed at reducing tick populations, may be placed in mouse habitats. Damminix™ which does not kill the mice consists of cardboard tubes filled with permethrin-treated cotton balls that mice use as nesting material.
A careful tick check is the most effective way to protect you and your family from Lyme disease. After outdoor activities, brush off clothing thoroughly and do a visual inspection paying particular attention to folded areas such as cuffs, belts and shirt collars.
Do a complete body check on a daily basis. Check children more frequently. Carefully inspect the hairline and scalp as well as difficult-to-see areas such as the back. A daily shower or bath is advised as unattached ticks can be washed off.
Ticks may hitchhike indoors on pets or clothing and then fall off. Pets should be checked on a regular basis, particularly around the eyes, ears and underbelly.
A tick's mouthparts are barbed like a fish hook. Once inserted, a cement-like substance is released, making tick removal difficult. Proper and prompt removal of ticks includes the following:
- Grasp the tick at the point of attachment using fine tipped tweezers. Do not squeeze the body.
- Pull straight out with slow and steady pressure. Avoid twisting the tick.
- Apply an antiseptic to the bite area.
- If the tick is difficult to remove, consult your physician.
- Do not apply petroleum jelly, nail polish remover, or a hot match to the tick. This will not make the tick back out.
- For proper identification, place the tick in a vial or small bottle and bring or send to:
Cape Cod Cooperative Extension
P.O. Box 367, Deeds and Probate Bldg.
Railroad Ave, Barnstable, MA 02630
Many people do not realize they have been bitten by a tick, particularly by the nymphal stage. Early symptoms may vary among individuals:
- Chills and fever
- Prolonged fatigue
- Muscle and joint pain
- Circular skin rash that increases in size
Many patients do not develop a rash. If you suspect the possibility of Lyme infection do not wait. See a doctor right away. Antibiotics can be prescribed to help treat this disease. This is especially important in such highly endemic areas such as Cape Cod and the Islands. Delayed treatment may result in late Lyme disease with major medical problems such as potentially serious heart, nervous system, and arthritic conditions. A vaccine is now available; consult your physician as to whether it is appropriate for you.
Diagnosis of Lyme disease is often difficult as symptoms of Lyme disease may mimic those of other illnesses. Blood tests are not always reliable. Antibiotics are generally prescribed for treatment. Dosages, duration, and mode of administration are a matter of medical controversy.
We now know that, once transmitted from the tick, the bacteria can move very quickly from beneath the skin to deeper tissues in the body (before the blood tests can detect evidence of illness).
Thus, in highly endemic areas, following the removal of an engorged deer tick, some physicians may choose to treat preventatively before symptoms arise.More Information
Brewster Health Department
508-896-3701 Extension 120
Barnstable County Department of Health and the Environment
Superior Court House
Cape Cod Cooperative Extension
Deeps and Probate Building
Route 6a Barnstable MA 02630
Nantucket Board of Health
37 Washington Street
Nantucket, MA 02554
UMASS Vineyard Extension
PO Box 1696
Oak Bluffs, MA 02557
Information from the Centers for Disease Control and Prevention, Massachusetts Department of Public Health, Southampton Hospital (NY), Tick Research Lab, University of Rhode Island, and National Park Service was used to prepare this brochure. Additional information may be obtained from the Cape Cod Lyme Awareness Association, PO Box 1916, Mashpee, MA 02649
This webpage based on a pamphlet courtesy of The Barnstable County Dept. of Health & Environment; P. O. Box 427; Barnstable MA 02630-0427.