Walking Well: Lyme Disease

"Oh my God! It's a tick! I'll catch Lyme disease! I'll be crippled for life or die for sure!"

Lyme disease ranks high in the concerns of hikers, with some justification. It is true that untreated cases can become severe, with long-lasting complications. I have 3 letters from hikers who have had problems and concerns. The good news is that it is easily prevented and treated. What is the real story? Here is a brief summary of current medical knowledge.

History
In 1975 a bunch of Connecticut kids out playing in the woods came down with a new mysterious skin disease and arthritis near the town of Lyme. It was originally thought to be a form of juvenile rheumatoid arthritis, but the local medics soon figured it out. And now we have cases of the disease in all states.

Incidence
Although one should be vigilant everywhere, Connecticut is by any measure the state of greatest concern, closely followed by New Jersey, New York, Pennsylvania, Massachusetts and Maryland. This ranking takes into consideration the density of the disease (number of cases in a state per square mile) and the number of AT miles in the state.

Etiology
The disease is caused by an infection by a spirochete, Borrelia burgdorferi like that which causes syphilis (Treponema pallidum). These spirochetes mainly infect white-footed mice (also the reservoir of Hanta virus disease). These mice also harbor deer ticks, Ixodes dammini, during the immature phase of the tick. While these ticks suck mouse blood to grow they become infected by the spirochetes. When mature they seek and mainly live on deer, but also on dogs and other mammals. Passing deer transfer the infected ticks to vegetation. People brush against these plants and the ticks grab skin and seek blood, injecting the spirochetes.

Prevention
There is a new vaccine for Lyme disease, and if you spend a great deal of time outdoors in tick-infested areas, you should certainly discuss it with your physician.

Although you can avoid Lyme disease by staying out of the woods, avoiding grass and bushes, completely covered by impenetrable clothing, this is obviously impossible for AT hikers. When hiking you should diligently search your body for ticks daily, especially in high-incidence states. Since most tick bites occur in May through August, cooler weather hiking is a little safer. Deer ticks are very small and are found in 3 forms: larval, nymph and adult. The immature or larval form is mainly hatched in early spring and is about 0.5 to 1 mm in diameter, the size of the wire in a paper clip, clear, nearly invisible, but infectious. Later the nymphs are about 1 mm in diameter and dark brown. The adults are about 2 mm in diameter, dark brown and about the size of a poppy seed. They can become maximally engorged with blood up to 5 to 6 mm. Do not be complacent about larger ticks, which can transmit other diseases (Rocky Mountain Spotted Fever, prevalent in North Carolina, for example).

If you find a tick of any size, scrape it off with a sharp blade or pull it off slowly with tweezers and disinfect the area with soap and water or a local disinfectant (iodine, alcohol, etc.). Note that a tick is usually attached for at least 24 hours in order to cause an infection, so that prompt removal will markedly reduce the risk. Even if some of the mouth parts remain in the skin this does not cause a problem. If you hike the AT wearing shorts, avoid brushing against grass and bushes as much as possible; wearing gaiters is helpful since ticks generally attach near the feet or ankles. DEET and other insect repellents may help.

Symptoms and Treatment
If you think you've been bitten by a deer tick and want to know more about Lyme disease symptoms and treatment, contact your physician. Bear in mind that the vast majority of deer tick bites do not result in the victim contracting Lyme disease.