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Lyme disease: a growing threat to urban populations
1Division of Rheumatology/Immunology, Tufts University School of Medicine, New England Medical Center, Boston, MA 02111.
Abstract:
Lyme disease or Lyme borreliosis, which is caused by three groups of the spirochete Borrelia burgdorferi, is transmitted in North America, Europe, and Asia by ticks of the Ixodes ricinus complex. The primary areas around the world that are now affected by Lyme disease are near the terminal moraine of the glaciers 15,000 years ago. The emergence of Lyme disease in the United States in this century is thought to have occurred because of ecological conditions favorable for deer. From 1982 through 1991, 40,195 cases occurring in 47 states were reported to the Centers for Disease Control, but enzootic cycles of B. burgdorferi have been identified in only 19 states. During the last several decades, the disease has spread to new areas and has caused focal outbreaks, including locations near Boston, New York, and Philadelphia. Lyme disease is like syphilis in its multisystem involvement, occurrence in stages, and mimicry of other diseases. Diagnosis of late neurologic abnormalities of the disorder has created the most difficulty. A recent phenomenon is that a number of poorly understood conditions, such as chronic fatigue syndrome or fibromyalgia, are misdiagnosed as "chronic Lyme disease." Part of the reason for misdiagnosis is due to problems associated with diagnostic tests. The various manifestations of Lyme disease can usually be treated successfully with oral doxycycline or amoxicillin, except for objective neurologic manifestations, which seem to require intravenous therapy. Vector control of thick-borne diseases has been difficult and, therefore, reduction of the risk of infection has been limited primarily to personal protection measures.
Insights
Lyme disease, a tick-borne illness caused by Borrelia burgdorferi, has spread across North America and Eurasia. Early diagnosis and treatment are key, though challenges remain in managing late-stage neurological symptoms and combating misdiagnosis.
Area of Science:
- Infectious Diseases
- Epidemiology
- Tick-Borne Illnesses
Background:
- Lyme disease, or Lyme borreliosis, is caused by Borrelia burgdorferi spirochetes and transmitted by Ixodes ticks.
- Geographic spread is linked to glacial moraines and favorable deer ecology, with significant case increases reported in the US.
- The disease presents in stages, mimics other conditions, and poses diagnostic challenges, particularly in late neurological presentations.
Purpose of the Study:
- To provide an overview of Lyme disease epidemiology, clinical presentation, and management.
- To highlight diagnostic difficulties and the issue of misdiagnosis with conditions like chronic fatigue syndrome.
- To discuss treatment strategies and limitations in vector control for tick-borne diseases.
Main Methods:
- Review of reported Lyme disease cases from the Centers for Disease Control (CDC).
- Analysis of geographic distribution and historical spread patterns.
- Comparison of Lyme disease manifestations with other conditions and diagnostic challenges.
Main Results:
- Over 40,000 cases reported in the US between 1982-1991, with enzootic cycles in 19 states.
- Focal outbreaks have occurred in new areas, including near major East Coast cities.
- Misdiagnosis is common due to overlapping symptoms and diagnostic test limitations, especially for "chronic Lyme disease."
Conclusions:
- Lyme disease requires careful diagnosis, with late neurological symptoms posing the greatest challenge.
- Standard oral antibiotics are effective for most manifestations, but intravenous therapy may be needed for neurological issues.
- Personal protection remains the primary method for reducing infection risk due to difficulties in vector control.