Tue, Jul 22, 2008 page16

• Danger in a grassy stroll

  Lyme disease, a common tick-borne illness in the Northern Hemisphere, is maddeningly difficult to diagnose — but late or inadequate treatment can lead to debilitating chronic symptoms

  • By Jane E. Brody / NY TIMES NEWS SERVICE
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  My friend Anne and her husband, Richard, spend summers at a resort in Westchester County, New York, that has a swimming lake, tennis courts, gardens and beautiful grounds surrounded by woods. But Anne never sets foot on the grass.

  The reason is Lyme disease. Anne says just about everyone she knows who partakes of the greenery and gardens outside the cabins has contracted the disease. So not only is she cautious about venturing out, but she and her husband also check each other daily from head to toe for the much-feared deer tick, which can transmit the disease when it attaches to skin and feeds on blood.

  This tick, which is the size of a pinhead when it starts searching for a bloody meal, is responsible for about 20,000 reported cases of Lyme disease each year in the US (the actual number is believed to be 10 times that) and 60,000 reported cases in Europe. Cases have been reported in every state, with residents of the Northeast, the Great Lakes region, northwestern Washington state and parts of California the most frequent victims.

  

  ILLUSTRATION: NY TIMES NEWS SERVICE

  In some areas, as many as half of the deer ticks are infected with Borrelia, the Lyme disease bacterium. The disease got its name in 1975 from the first identified cluster of cases, among children in Lyme, Connecticut, who had rheumatoid-like symptoms of swollen, painful joints.

  The white-tailed deer and white-footed mouse are the tick’s most frequent hosts, but it also feeds on birds, dogs and other rodents, including squirrels. The tiny nymphal form that emerges in spring and early summer presents the greatest hazard to humans. It is also the hardest to spot, especially on body parts covered with hair.

  People usually acquire the tick while walking through grassy or wooded areas. Sometimes pet dogs are the source: In Minnesota one summer, our dog got more than 30 deer ticks on his face, apparently from sticking his nose into a fresh carcass. Unlike the common dog tick, which is round and very dark, the deer tick is elongated and brownish.

  The disease can be maddeningly difficult to diagnose. Only 50 percent to 70 percent of patients recall being bitten by a tick. Ordinary laboratory tests are rarely helpful. Tests for antibodies to the bacterium or for its genetic footprints result in many false-negative and false-positive findings.

  Rather, according to Robert L. Bratton and colleagues at the Mayo Clinic in Scottsdale, Arizona, who reviewed the recent literature on Lyme disease in the May issue of Mayo Clinic Proceedings, most cases are best diagnosed and treated based on patients’ symptoms. Thus, doctors everywhere must be alert when dealing with patients who live or travel in areas where Lyme disease is prevalent, and they must be willing to use appropriate antibiotics based on a clinical assessment rather than laboratory findings.

  EARLY SYMPTOMS

  Since signs and symptoms vary and often do not appear until one to four weeks — or even months — after exposure, anyone bitten by a deer tick may be wise to obtain preventive treatment with an antibiotic, according to Lyme disease experts consulted by Constance A. Bean, the author with Lesley Ann Fein of the new book Beating Lyme.

  The most common sign is a reddish rash called erythema migrans that often resembles a spreading bull’s-eye, though up to 20 percent of patients never develop it. Common sites of the rash are the thigh, groin, buttock and underarm. It may be accompanied by flu-like symptoms: fever, chills, body aches, headache and fatigue.

  If untreated or inadequately treated, the infection can cause severe migrating joint pain and swelling, most often in the knees, weeks or months later. In addition, several weeks, months or even years after an untreated infection, the bacterium can cause meningitis, temporary facial paralysis, numbness or weakness of the arms and legs, memory and concentration difficulties and changes in mood, personality or sleep habits. Some untreated patients develop temporary heart rhythm abnormalities, eye inflammation or hepatitis.

  Antibiotics for early Lyme disease should be taken for at least two to three weeks. The treatments recommended by the Infectious Diseases Society of America include doxycycline for nonpregnant patients and children 9 and older, or amoxicillin for pregnant women and younger children. Other options include cefuroxime axetil (Ceftin) and erythromycin.

  But these guidelines are controversial. They have been challenged by a nonprofit medical group, the International Lyme and Associated Diseases Society, which says they are inadequate to combat the infection in a significant number of patients, who go on to develop debilitating chronic symptoms.

  In May, the Infectious Diseases Society agreed to review its guidelines as a result of an antitrust lawsuit by the Connecticut attorney general, Richard Blumenthal, who said some of the society’s experts had financial interests that could bias their judgment. (The society denied that accusation.)

  Although I cannot state with authority which side is correct, I have encountered enough previously healthy people who have suffered for months or years after initial treatment to suggest that there is often more to this disease than “official” diagnostic and treatment guidelines suggest.

  Pamela Weintraub, a senior editor at Discover magazine, has produced a thoroughly researched and well-written account of the disease’s controversial history in her new book Cure Unknown: Inside the Lyme Epidemic.

  WASH THOROUGHLY

  The Mayo doctors concluded that patients who developed arthritis related to Lyme disease should be treated for one to two months and that those with late or severe disease, including neurological and cardiac symptoms, required intravenous antibiotics. Although two studies, neither of which was long-term, found that repeated antibiotic treatment did not reverse the pain and altered cognition associated with Lyme disease, the experience of thousands of patients, including Bean, contradict these findings.

  There are no vaccines to prevent Lyme disease; an early attempt was taken off the market in 2002 because of side effects and limited effectiveness. Those who will not or cannot avoid grassy and wooded areas should wear long sleeves and long pants with legs tucked into socks, and spray exposed skin and clothing with tick repellent containing 20 percent to 30 percent DEET. Repellents should not be used on children under 2.

  Since the tick must usually feed for 24 hours to transmit significant amounts of bacteria, daily body checks and showering with a washcloth can help prevent infection. Clothing should be washed and dried in a dryer. Additional preventive actions are described in Beating Lyme.

  If a tick is attached to skin, it should be removed with tweezers, not fingers. Press into the skin, grasp the front of the tick’s head and pull at right angles to the skin. Place the tick in a sealed plastic bag for later identification. Then wash the area and your hands thoroughly.
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