NEUROLOGIC COMPLICATIONS OF LYME DISEASE

Treatment of Lyme disease: a medicolegal assessment

Lyme disease is the most common tick-borne disease in the world today. Despite extensive research into the complex nature of Borrelia burgdorferi, the spirochetal agent of Lyme disease, controversy continues over the diagnosis and treatment of this protean illness. This report will focus on two aspects of the treatment of Lyme disease. First, the medical basis for diagnostic and therapeutic uncertainty in Lyme disease, including variability in clinical presentation, shortcomings in laboratory testing procedures, and design defects in therapeutic trials. Second, the standard of care and legal issues that have resulted from the clinical uncertainty of Lyme disease diagnosis and treatment. Specifically, the divergent therapeutic standards for Lyme disease are addressed, and the difficult process of creating treatment guidelines for this complex infection is explored. Consideration by healthcare providers of the medicolegal issues outlined in this review will support a more rational approach to the diagnosis and treatment of Lyme disease and related tick-borne illnesses.

Experimental induction of chronic borreliosis in adult dogs exposed to Borrelia burgdorferi-infected ticks and treated with dexamethasone

OBJECTIVE

To develop a method to experimentally induce Borrelia burgdorferi infection in young adult dogs.

ANIMALS

22 healthy Beagles.

PROCEDURE

All dogs were verified to be free of borreliosis. Twenty 6-month-old dogs were exposed to Borrelia burgdorferi-infected adult ticks and treated with dexamethasone for 5 consecutive days. Two dogs not exposed to ticks were treated with dexamethasone and served as negative-control dogs. Clinical signs, results of microbial culture and polymerase chain reaction (PCR) testing, immunologic responses, and gross and histologic lesions were evaluated 9 months after tick exposure.

RESULTS

Predominant clinical signs were episodic pyrexia and lameness in 12 of 20 dogs. Infection with B burgdorferi was detected in microbial cultures of skin biopsy specimens and various tissues obtained during necropsy in 19 of 20 dogs and in all 20 dogs by use of a PCR assay. All 20 exposed dogs seroconverted and developed chronic nonsuppurative arthritis. Three dogs also developed mild focal meningitis, 1 dog developed mild focal encephalitis, and 18 dogs developed perineuritis or rare neuritis. Control dogs were seronegative, had negative results for microbial culture and PCR testing, and did not develop lesions.

CONCLUSIONS AND CLINICAL RELEVANCE

Use of this technique successfully induced borreliosis in young dogs. Dogs with experimentally induced borreliosis may be useful in evaluating vaccines, chemotherapeutic agents, and the pathogenesis of borreliosis-induced arthritis.

Lyme disease in transgenic mice expressing the Borrelia burgdorferi flagellin epitope implicated in human neuroborreliosis

Because of an association of human neuroborreliosis with the development of an antibody response against an antigen in neural tissue that cross-reacts with an epitope on the flagellin protein of Borrelia burgdorferi, C3H transgenic mice were created that expressed the flagellin epitope (amino acids 213-224) as a fusion protein with myelin basic protein. The transgenic mice expressed the flagellin epitope selectively in myelinated regions of the nervous system. Both transgenic and non-transgenic mice developed an antibody response to the flagellin epitope during B. burgdorferi infection and both developed arthritis and carditis. However, no lesions were found in the central nervous system of either type of mouse for up to 8 weeks after infection. The data indicate that expression of the flagellin 213-24 epitope in mice does not result in neurologic disease, suggesting that B. burgdorferi flagellin antibodies may not be directly implicated in neuroborreliosis.