Evidence-based practice guidelines for the treatment of Lyme disease
—a bacterial infection that is transmitted to humans by deer ticks and is endemic in parts of the U.S.—were issued recently by the Infectious Diseases Society of America. The guidelines are the first evaluation of Lyme disease treatments using a disciplined, systematic, rules-of-evidence approach to the published literature, and are meant to complement existing standards of practice.

"The guidelines were developed to provide physicians and other health care practitioners with recommendations for managing patients who have been diagnosed with Lyme disease, or who have been bitten by ticks suspected of carrying the disease," said Peter A. Gross, M.D., IDSA Council member and chair, department of internal medicine, Hackensack University Medical Center, N.J. The guidelines are published in the current issue of the journal, Clinical Infectious Diseases. "

"Lyme disease is the most common tick-borne disease in the U.S. In some cases, it can cause serious health problems, especially if not treated appropriately," said Gary P. Wormser, M.D., co-author of the guidelines and chief, division of infectious diseases and vice-chairman, department of medicine, New York Medical College, Valhalla. "It is our hope that these guidelines will improve prevention, recognition and treatment of Lyme disease, and reduce the incidence and severity of the disease, and the frequency of misdiagnosis and inappropriate treatment."

The evidence-based guidelines were derived from published data from clinical trials and other studies, and the opinions of a panel of 12 infectious disease specialists with collective expertise in clinical, medical entomologic and public health aspects of Lyme disease. The guidelines recommend:

• Prevention remains the best approach. If exposure to ticks is unavoidable, protective clothing and tick repellents should be used. "The entire body should be inspected daily and ticks removed at once, since they are less likely to transmit Lyme disease or other diseases if they have been attached for less than 48 hours," Dr. Wormser said.

• Persons who remove attached ticks should be monitored closely for signs of illness—particularly a rash at the site of the tick bite—for up to 30 days.

• Patients with early Lyme disease should be treated with a 14- to 21-day course of antibiotics. Symptoms of early Lyme disease, which appear within days to weeks following a bite by an infected tick, may include a slowly expanding red rash, often associated with fatigue, fever, headache and stiff neck, muscle aches and joint pain. Antibiotics used to treat Lyme disease usually include doxycycline, amoxicillin or, in some cases, cefuroxime axetil.

• If untreated or inappropriately treated, some patients may develop signs and symptoms weeks to months later, including intermittent episodes of swelling and pain in the large joints, a condition known as Lyme arthritis; neurologic problems, such as meningitis, facial paralysis, motor and sensory nerve inflammation and inflammation of the brain; and, in rare cases, heart block. Some patients may experience these later symptoms without having noticed any early signs of disease. The IDSA guidelines contain recommendations for treating late Lyme disease in such patients.

• Patients who experience persistent or recurrent joint swelling after completing the recommended first course of antibiotics for Lyme arthritis should be re-evaluated and retreated with antibiotics as appropriate. Treatment with non-steroidal anti-inflammatory agents, intra-articular steroids (steroids injected into the joint) or arthroscopic synovectomy (a minimally-invasive surgical procedure in which inflamed tissue is removed from the affected joint) may be useful in arthritis that does not respond to retreatment with antibiotics.

• Physicians and other health care providers should make themselves familiar with the clinical signs, diagnosis and treatment of Lyme disease, particularly in areas where the disease is endemic.

• Patients who have been vaccinated with a recently approved vaccine for Lyme disease are at lower risk of acquiring the disease, but prior vaccination should not alter the above recommendations.

"While the guidelines reflect current scientific knowledge about Lyme disease, further research is needed," said Dr. Wormser. "There are still unanswered questions, particularly in that small subset of patients who continue to experience symptoms weeks or months after appropriate treatment with antibiotics.

"The consensus reached by the expert panel was that, to date, there are no convincing published data that repeated or prolonged courses of either oral or intravenous antibiotic therapy are effective for such patients. We also concluded that there is insufficient evidence to regard ‘chronic Lyme disease’ as a separate diagnostic entity. Research is under way that we hope will shed more light on this issue," he said.

According to Dr. Wormser, the National Institute of Allergy and Infectious Diseases, a division of the National Institutes of Health (NIH) is currently funding a multicenter, randomized controlled study of this group of patients.

According to the CDC, the number of reported cases of Lyme disease in the United States has increased 30-fold since national surveillance began in 1982. Currently, approximately 15,000 cases are reported each year. In the United States, the disease occurs most frequently in the northeast, mid-Atlantic and upper north-central regions, and in some areas of northwestern California. The disease is caused by the corkscrew-shaped bacteria, Borrelia burgdorferi.