Terror of the woodlands--the Lyme disease tick

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The tiny insect carries a cargo of bacteria capable of causing debilitating disorders

A new hazard to add to poison ivy, stinging insects, and other noxious things to avoid while taking jaunts in the Great Outdoors is a tick whose bites can prompt the symptoms of arthritis, depression, Alzheimer's disease, multiple sclerosis, and heart disease, among other maladies. The pinhead-sized tick, which lives in grasslands and wooded areas, often harbors the bacteria that cause Lyme disease.

Dubbed "the Great Imitator," Lyme disease is a growing public health menace as its tick carrier expands its range in the U.S.A. Fortunately, the disease can be treated with commonly used antibiotics, but its numerous disguises often allow it to slip unseen through medical exams.

A tricky case for medical detectives, the disease first made its debut in this country in 1975, in Lyme, Conn., hence its name. The disease was masquerading then as rheumatoid arthritis. Two women had become concerned by the large number of adults and children, theirs included, in Lyme who had recently been diagnosed as having rheumatoid arthritis. The women alerted the Connecticut State Health Department. Officials there convinced rheumatologist Dr. Allen Steere, then at Yale University, to investigate the situation.

Steere discovered that in Lyme and two of its neighboring towns, juvenile rheumatoid arthritis, a debilitating disorder whose hallmark is painful swollen joints, was 100 times more common than normal. Most of the arthritis cases started in the summer months during tick season. One quarter of the patients interviewed by Steere, moreover, reported having a skin rash just before their arthritis developed and several of these patients recalled being bitten by a tick at the rash site. Further investigations by Steere and Dr. William Burgdorfer of the National Institute of Allergy and Infectious Diseases allowed scientists to pinpoint the culprit tick, called Ixodes datnmini, and the spiral-shaped bacteria it harbors that caused the outbreak of arthritis in Lyme. The bacterium was labeled Borrelia burgdorferi.

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Since the initial 50 cases of Lyme disease cropped up in Connecticut in 1975, more than 5,000 cases from 33 states have been reported to the Centers/or Disease Control (CDC). These figures put the disease at the top of the list of common tick-borne diseases, according to CDC, making it more common than Rocky Mountain spotted fever.

Lyme disease has also been found in Europe, Asia, Australia, and Africa. Although it appears to be a new disease, undiagnosed cases of Lyme disease are to be found in medical literature dating back to 1887 in Australia and 1909 in Sweden. The disease probably spread from Europe to the United States and became common enough to be detected because of our expanding deer population, scientists spectulate (Ixodes often preys upon deer.)

Most cases of Lyme disease in the United States are concentrated in the coastal Northeast, northern California and Oregon, and Wisconsin and Minnesota. On the West Coast, the Lyme disease bacteria are harbored by a close cousin of Ixodes dammini called Ixodes pacificus.

Not only has the incidence of Lyme disease multiplied, but the list of symptoms it is known to prompt has also been expanding as medical researchers get a better handle on the short-long-term manifestations of the deceptive disease.

Studies of Lyme disease patients who are not treated with antibiotics reveal that the first sign of the disorder is usually a bull's-eye insignia -- a small red pimple that later expands to form a ring-shaped rash. This rash, called erytherna chronicum migrans, typically has a bright red outer border and a partially clear central area. The bull's-eye, which ranges in size from that of a dime to extending over a person's back, can mark the spot where the tick bite occurred, or several of them can crop up at different sites on the body. The rash may be accompanied by flu-like symptoms, such as headache, stiff neck, body aches, and fatigue. These initial symptoms usually start within a month after the tick bite.

Although some people infected with Lyme don't experience any symptoms other than the rash, which eventually heals, most untreated Lyme disease patients develop more serious consequences, the most common being arthritis. This arthritis usually develops within weeks -- but in some cases years -- after the tick bite. Most Lyme disease patients experience recurrent attacks of swollen and painful joints that last a few days to a few weeks.

The main joint afflicted by Lyme arthritis is the knee. Many patients with Lyme arthritis are incorrectly diagnosed as having rheumatoid arthritis, which is understandable considering the symptoms are nearly the same. One study shows, in addition, that three-quarters of patients with Lyme arthritis never developed the telltale bull's-eye rash.

Lyme disease can also camouflage itself in heart disease symptoms. About 5 percent of patients have dizziness or shortness of breath, tied to an irregular heartbeat. Some of these patients may require a pacemaker, although these symptoms usually don't last more than two months. Heart abnormalities generally crop up about a month after the bull's-eye rash.

To further confuse the physician, Lyme disease can also disrupt the nervous system, causing meningitis, paralysis of the facial muscles, memory loss, depression, inability to concentrate, and poor motor coordination as in multiple sclerosis. Lyme disease bacteria have been found in the degenerated brain tissue of some patients with Alzheimer's disease, prompting a few researchers to suspect that Lyme disease is at the root of these patients' senility.

It is not known why the Lyme disease bacterium can disrupt the body in so many different ways. Researchers suspect that an irritated immune system releases a battery of destructive compounds to combat the Lyme bacteria, inadvertently damaging the joints and other tissues.

Given its multiple disguises, Lyme disease is difficult to pin down. The biggest clue doctors have is knowing that their patients have been bitten recently by the Ixodes tick. But this tick bite, which sets the disease in motion, often goes undetected by its victims. Evidence from Europe, where Lyme disease has a longer history, indicates that symptoms may not appear until several years after patients are initially infected by a tick bite.

The bull's-eye insignia is another important clue doctors rely on for a Lyme disease diagnosis, but not all Lyme disease sufferers show it. Now that Lyme arthritis has been studied for several years, its pattern can be distinguished from other forms of arthritis, according to Steere, and this will aid diagnosis. But the distinguishing nervous system abnormalities tied to Lyme disease are not clearly defined yet, he adds. "Lyme disease is tricky to diagnose because the outer limits [of the symptoms it can cause] are not know yet," he says.

Once a diagnosis of Lyme disease is made, the hard part is generally over because the disease is treatable, especially in its early stages. Antibiotics (such as tetracycline or penicillin) taken orally can speed the healing of the rash as well as prevent or lessen the severity of subsequent symptoms. Tetracycline should not be given to pregnant women or children under 8, however, because it can stain the teeth of a child or unborn baby.

High doses of penicillin or ceftriaxone given intravenously or via shots are often required to rid the body of the abnormalities of the nervous system, heart, or joints that Lyme disease can prompt.

Lyme disease patients that go for several years without treatment because of false diagnoses still can often be cured with the proper antibiotic regimen. If the disease has persisted long enough, however, it may irreversibly damage the structure of the joints or nervous system so that the arthritic or multiple sclerosis-like symptoms, for example, will persist in spite of appropriate antibiotic treatment.

Because Lyme disease can be transmitted via blood, particularly when a person is experiencing the initial stages of the illness, Lyme disease patients should not donate blood.

Unfortunately, a bout with Lyme discease is no guarantee of not succumbing to the illness again in the future. The disease can strike more than once in the same person if he or she is reinfected with Borrelia burgdorferi.

The easiest way to avoid Lyme disease is to steer clear of the ticks that transmit it. These ticks are most likely to be out and biting from late spring through summer. They prefer wooded areas and nearby grasslands and are especially common where the two habitats intersect. In these areas, they pounce on white-tailed deer, field mice, other wild animals, and, given the opportunity, humans as well.

If you are out romping in areas known to be infested by ticks carrying Lyme disease, use tick repellent and wear long pants and long-sleeved shirts that fit tightly at the ankles and wrists. As a further safeguard, tuck your pant legs into your socks and wear shoes that leave no port of your feet exposed. Ticks will be easier to detect on light-colored clothing.

Once indoors, do a thorough tick check all over your body, particularly the hairy regions. Be aware that the tick that carries Lyme disease is so tiny (about an eighth of an inch in diameter) that it is easily mistaken for a freckle or speck of dirt. Check pets for ticks before they enter the house, and wash all clothing.

If you discover a tick attacked to your skin, gently tug it out with tweezers, taking care not to squeeze the tick's body. Such squeezing can propel the tick's germs into your body. Apply an antiseptic such as rubbing alcohol to the bite, and save the tick in a jar for proper identification by your doctor if any Lyme symptoms develop.

Tick bites are not painful, and because there are many ticks that are disease-free, a tick bite does not mean you will automatically acquire Lyme disease. The more common wood (also called dog) tick can be distinguished from Ixodes by the white markings on its back and because it is nearly twice the size of Ixodes.

Pregnant women should be especially careful to avoid ticks in Lyme disease areas because the infection can be transferred to the unborn child. A preliminary study carried out by CDC indicates that such a prenatal infection can put the baby at higher risk for birth defects and make the woman more likely to miscarry or deliver a stillbirth.

There is no vaccine for Lyme disease, although researchers are pursuing this possibility. An effective vaccine may be tricky to concoct because the Lyme disease bacterium is notorious for changing its protein coat, thereby deceiving the immune system defenses that vaccines prompt.

Experts attribute the current spread of Lyme disease to the expanding range of the tick that carries it. Such expansion is probably aided by migratory birds, which carry the ticks long distances, and an increasing deer population on which the ticks feed. But no one knows exactly what factors are critical to the tick's spread or how to curb that spread.

PHOTO: Although deer are the tick's favorite victims, other species such as rabbits, mice, dogs and cats are also vulnerable to the bite of the Insect.

PHOTO: Shown above is pictured a female Ixodes damnini (enlarged 26 times), the tick that carries Lyme disease. The Insect shown on the left has not fed recently; on the right is a tick engorged by a meal of blood.

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By Margaret Patlak

(Adapted from FDA Consumer 7/88)

SYMPTOMS IN DOMESTIC ANIMALS
Lyme disease can affect individual pets differently. Some animals may display no symptoms. Others may have fever, loss of appetite, painful joints, lethargy, and vomiting. If left untreated, the spirochete may damage the eyes, heart, kidneys, and nervous system. Lyme disease has been diagnosed in humans, dogs, cats, horses, goats, and cattle. Other species may also be at risk.

Cats:
Cats may show lameness, fever, loss of appetite, fatigue, eye damage, unusual breathing, or heart involvement.

Dogs:
Infected dogs may be lethargic, have a poor appetite, or a fever (103 degrees-105 degrees). Dogs may experience lameness shifting from one joint to another, fatigue, fever, loss of appetite, kidney failure, heart disorders, behavioral changes, or seizures. Dogs can be infected with the bacterium B. burgdorferi but not exhibit any symptoms.

Dogs appear to have the same expression of disease as humans and therefore may be considered an animal model.

Horses:
Infected horses generally do not have a fever, but they may be lame or stiff in the joints, depressed, or refuse to eat. This bacterial infection may be a cause of moon blindness or loss of vision. There have been reports of spontaneous abortion and encephalitis in horses infected with B. burgdorferi. Neurologic signs include head tilt, difficulty swallowing, and aimless wandering. Colts born to infected mares have displayed birth defects.* Many horses may be infected with the spirochete, but display no symptoms.

* Controversial.

DIET AND LYME DISEASE: THE AFTERMATH
People with longstanding Lyme disease end up in poor physical condition. Even with successful treatment of the Lyme infection, they will not return to normal unless they take an active role in personal rehabilitation.

In late-stage disease, many negative effects to the body occur. The muscles atrophy, and to some degree the heart muscle also suffers, as do the joints, nerves, liver, and other structures.

Besides these physical effects, chemical changes occur. The fat content of the body as a whole rises, the cholesterol rises, and the balance between high-density lipoprotein (HDL) and low-density lipoprotein (LDL) becomes less favorable. At least 80% of the patients experience significant weight gain.

To make matters worse, because of the extreme fatigue and body pain, many Lyme disease patients end up spending inordinate amounts of time in bed and get far less exercise than they had before they became ill.

As a result of all this, patients are stiff, weak, and tired; they have poor stamina and are at increased risk for cardiovascular disease and diabetes.

Therefore, a vital part of any plan for recovery must include various forms of physical therapy, the extent of which depends on an individual patient's condition.

The earliest phase involves multiple modalities (massage, heat, ultrasound) and simple range-of-motion exercises to relieve discomfort and to promote better sleep and flexibility. This then evolves into stretching and mild muscular strengthening, which can lessen joint pain and increase mobility and stamina. Finally, the program must include some form of aerobic conditioning.

Diet also plays an important role. This is the time for the very best of health habits. Recommended are light, low-fat foods with high nutritional value. Further fortification should include daily intake of vitamin-mineral supplements, including beta-carotene, vitamin B-complex, vitamin C, vitamin E, calcium with magnesium, and potassium. Foods that contain these nutrients are preferable to pills.

Patients with Lyme disease should also abstain from alcohol, caffeine, and tobacco. A serious commitment to weight loss, if applicable, is desirable.

PHOTO: The shadow of the deer tick falls across the country.

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