Bob politely interrupted the class I was teaching on tick-borne
illnesses. ‘Could this be what you’re talking about?’ he asked.
Standing, he pulled up the leg of his shorts to reveal a
well-defined reddish spot on his upper thigh, about three inches at
its widest, darker toward the outer edge.
‘I’ve got a couple more,’ he said, and proceeded to expose those
to the rest of the class. ‘They’ve been getting bigger,’ he
added.
Bob denied any knowledge of being tick bitten, but it looked
like erythema migrans to me, the characteristic rash that announces
Lyme disease in somewhere between 60 and 80 percent of patients.
The rash may develop where the tick bit or anywhere else on the
body, with a tendency to show up most often on thigh, groin, armpit
and sometimes behind the knee. After it first appears, the rash
grows, or ‘migrates.’ If erythema migrans emerges in the first week
of the disease, the spots rarely grow to more than 2.5 inches
across. Spots appearing two to four weeks later may reach eight
inches across. The red rash typically feels warm and may cause a
burning sensation, but seldom produces pain or itching.
Any more indications of illness? I inquired. ‘Something like the
flu,’ Bob said, describing more of the early symptoms of Lyme
disease-low-grade fever, headaches, unusual fatigue and muscle
aches.
Infecting more than 15,000 North Americans annually, Lyme
disease is the leading disease borne by carrier organisms, or
vectors, in the U.S. Yet the illness remains widely overlooked.
Often misdiagnosed or left untreated, it may resolve itself in the
first month, but about half the cases will progress to more serious
levels. Dubbed ‘the great imitator,’ Lyme disease mimics many
common ailments. Physicians can easily draw the wrong conclusion
about an infected patient’s ‘obvious’ symptoms, ruling out Lyme
disease and treating one of its imitated illnesses instead.
Early symptoms are often mild enough to be ignored. The rash
doesn’t always appear. And the ticks can go unnoticed, typically
attaching themselves during the nymphal stage between May and
August, when they take up less room than a poppy seed on your skin.
‘Many of the worst cases of Lyme disease were contracted a decade
ago when people were not as aware of the illness,’ says David L.
Weld, executive director of the American Lyme Disease Foundation.
But missing an early diagnosis continues to be a grave problem,
leading to debilitating headaches, neurological or cardiological
complications and Lyme arthritis, which attacks the larger joints,
particularly the knee.
I voiced my concerns to Bob and suggested a timely (in other
words, immediate) visit to a physician. The doctor took a blood
sample and tested for the corkscrew-shaped Borrelia burgdorferi,
the spirochete that causes the most common tick-borne disease in
the world. Bob was diagnosed: Lyme disease. The treatment was an
antibiotic, amoxicillin, for four weeks. The cure was complete.
The most common carriers of Lyme disease are the Ixodes ticks:
deer ticks in the East and Midwest, and black-legged ticks in the
West. After hatching from an egg in the spring, the larva feeds
once in summer on the first red blood source that passes by
(mammal, bird or reptile), picking up the spirochete if its meal is
an infected deer mouse or other small mammal. Going dormant in fall
and winter, the larva molts into a nymph during its second spring,
feeding several times its second summer and transmitting the
bacteria to humans if any should happen along. Later in the summer,
the nymph molts into an adult tick, which is active in late fall
through early spring. Easy to spot and remove, adult ticks have
less chance of transmitting Lyme disease to humans.
While ticks are the main source of transmission, Lyme disease
infections are boosted significantly by secondary agents. The
white-tailed deer provides a favorite base for ticks to launch
their attacks and is probably the worst if most unlikely-looking
culprit. Deer and tick populations tend to be directly
proportional. Wooded areas and small towns chock-full of Bambis
have thus become some of the worst nesting grounds for Lyme
disease. On Long Island, the town of North Haven has been hit hard
enough to win airtime on ’60 Minutes.’ With about 600 white-tailed
deer in the town’s two and a half square miles, it’s estimated that
half the residents have been infected with Lyme disease-though this
has remained a dormant issue until recently.First isolated and
named in Lyme, Connecticut, in 1975, Lyme disease has spread most
quickly in the Northeast, upper Midwest and northern California,
with substantial growth in the South. So you can relax on your
intended trip to Europe or Asia, right? Wrong, notes Weld. ‘You’re
at risk,’ he adds, ‘from a tick bite in all countries of the
northern hemisphere!’ And a similar syndrome occurs in Australia.
Although experts agree that the disease has been with us since long
before 1975, it was the evidence from the Connecticut outbreak that
proved ticks as the vector.
Woody and grassy areas can be thick with ticks from May through
September-with the bugs congregating especially in moist areas and
shade. They habitually crawl around for a while, perhaps weeks,
seeking a tasty place to feed. Blind or almost blind, all ticks
spend the mobile parts of their lives going up. They crawl until
bumping into a blade of grass, a bush, anything that provides
access to a higher place. They’ll wait at the tip of the grass or
bush for a meal to pass by. Once on your body, ticks may not stop
their meandering until they reach your scalp. Those that dig in
along the way demonstrate a preference for dark, moist body areas
such as behind the knee, the groin, around the waistline, under
breasts, in armpits and behind the ears. They feast on your blood
and drop off a couple of days to a week later. Along the way, they
pass on bacteria through their saliva, so the earlier they’re
removed, the less the chance of transmitting enough to cause
illness.
Tick checks, several times a day if you’re active outdoors, are
extremely important. If you wear light-colored clothing and tuck
your pants into your socks, you stand a good chance of recognizing
and removing the dark-colored tick before it reaches your skin.
Once indoors, shower (which should remove loose ticks) and give
yourself a close examination. Embedded ticks should be immediately
unembedded. Never apply oil, petroleum jelly, heat or anything else
to remove the embedded tick. With a pair of sharp-tipped tweezers,
grasp the tick as close to your skin as possible. Slowly pull it
straight out, and avoid squeezing it. Finally, scrub the area with
alcohol or an antibiotic ointment.
The New England Journal of Medicine has reported that ticks
attached for less than 48 hours rarely transmit Lyme disease. But
the risk escalates rapidly after this time. Tests on animals have
shown an 83 percent infection level after 72 hours, and 100 percent
if a tick is allowed to feed to repletion-over 120 hours.
Two repellents have proved effective in keeping ticks off. DEET
(N-diethyl-meta-toluamide), the active ingredient in most
repellents, may be applied to the skin. The Wilderness Medical
Society, a physician-oriented group, advises a concentration of
DEET no greater than 35 percent. Permethrin, a spray repellent sold
by Sawyer Products (800-940-4464), contains the active ingredient
permethrin and works on clothing. Permethrin doesn’t work on skin
directly, and can cause a rash or burn. On clothing, however, it
dries and actually kills ticks (and mosquitoes) on contact for up
to two weeks. The long-lasting effect of permethrin will allow you
to treat your clothes prior to many trips and leave the spray can
behind.
Two long-awaited vaccines for Lyme disease have become a new
source of excitement and possible relief-though they aren’t
available as yet. LYMErix, made by SmithKline and Beecham
Pharmaceuticals, and ImuLyme, from Pasteur Merieux Connaught, have
both tested favorably in research labs, though success rates still
vary somewhat according to age. At present, three doses of vaccine
have proven 90 to 100 percent effective in younger subjects. For
unknown reasons, the vaccines have had slightly lower success rates
with older subjects-currently only 75 percent for people over 60,
though a 12-month booster has been shown to raise this level
somewhat. Both companies are presently filing for licensing with
the Food and Drug Administration-but market approval is still
pending.
In the meantime, avoiding tick bites remains the best
preventative, and in case of a bite, prompt treatment is essential.
If you think you’ve got Lyme disease, see your physician as soon as
possible. Antibiotics prevent problems 98 percent of the time.
Treat it promptly, and ‘the great imitator’s’ act is easily
canceled.
For more information, you can contact the American Lyme Disease
Foundation at (914) 277-6970 or the Centers for Disease Control and
Prevention (CDC) at (888) 232-3228. Buck Tilton is director of the
Wilderness Medicine Institute.
FromEscape(Aug. 1999).
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