["Insect bite" and Borrelia].

Restriction endonuclease digestion of linear borrelial chromosomal DNA showed that three isolates of UK Lyme disease spirochaetes differed markedly from each other and from published data for other isolates from North America and continental Europe. Analysis of linear plasmid bands revealed that UK isolates differed from each other in the number and sizes of the plasmids in isolates from different foci of UK Lyme disease. Fatty acid analysis (of fatty acid methyl ester (FAME) profiles) showed the UK isolates clustering together with the relapsing fever spirochaetes, Borrelia turicatae and Borrelia parkeri. These data are discussed in respect of current knowledge of Lyme borreliosis in the UK.

Borrelia burgdorferi Group↗

PubMed1995

Erythema migrans and early Lyme disease.

Erythema migrans (EM) must be distinguished from other entities including streptococcal and staphylococcal cellulitis, hypersensitivity reactions to arthropod bites, plant dermatitis, tinea, and granuloma annulare. Although EM lesions may be pruritic or painful, these complaints are generally mild. Central clearing may be absent in > 50% of patients. Multiple lesions, formerly present in 50% of U.S. patients, now occur in approximately 20%. EM develops days to 1 month after a tick bite (median 7-10 days), and lesion diameter increases with duration. Most patients have associated complaints, with fatigue (54%), myalgia (44%), arthralgia (44%), headache (42%), and fever and/or chills (39%) being the most common. Respiratory and gastrointestinal complaints are infrequent. Symptoms may begin prior to the onset of, concomitant with, or after resolution of the rash. The incidence of viral-like illness due to Lyme disease without EM is unknown. Antibodies to Borrelia burgdorferi are absent in up to 50% of patients at presentation, with initial seropositivity most likely in those with EM of longer duration. The vast majority of patients will become seropositive within the first month of illness, even with treatment. Although there is evidence that B. burgdorferi can spread to the blood and central nervous system soon after onset of infection, oral therapy is highly effective in preventing objective extracutaneous complications of Lyme disease. The most appropriate choice, route of administration, and duration of therapy require further study. Because of variations in the etiologic agent between North America and Europe, comparisons of disease manifestations, treatment, and prognosis of Lyme disease must be made cautiously.

Borrelia burgdorferi Group↗

PubMed1995

Neuroborreliosis.

Lyme disease is a multisystem infectious disease with frequent nervous system involvement. It affects peripheral nerves, the meningeal lining of the central nervous system (CNS), and the CNS parenchyma, but the underlying pathophysiology remains unclear. Considerable data suggest that dividing Lyme neuroborreliosis into early and late disease stages, as has been done with syphilis--the other well-known spirochetosis that affects the nervous system--lacks pathophysiologic validity. Early CNS seeding has been demonstrated, however, and lymphocytic meningitis and facial paralysis tend to occur relatively early in infection, although radiculoneuropathy and cranial neuropathies may also occur later. Less fulminant forms of peripheral nerve or CNS involvement may present later in the disease course. Encephalomyelitis may occur early or late but is rare; encephalopathy is far more common and tends to occur in patients with evidence of systemic (but not necessarily CNS) Lyme disease. Diagnosis of CNS infection has been difficult, and most studies have relied on indirect methods. Demonstration of intrathecal production of anti-Borrelia burgdorferi antibodies provides the strongest evidence, but correction for the amount of peripheral blood immunoreactivity to B. burgdorferi that crosses the blood-brain barrier is essential. Newer technologies have been applied in an effort to improve detection of B. burgdorferi itself--polymerase chain reaction may provide a sensitive tool for organism detection to complement immunologic techniques. The optimal treatment regimen for Lyme disease has not been defined, but a course of ceftriaxone (2 g/day) or cefotaxime (6 g/day) for 3-4 weeks is commonly prescribed. Intravenous penicillin and oral doxycycline (200 mg/day) for 2 weeks have been used successfully to treat Lyme meningitis, but these results require confirmation.

Borrelia burgdorferi Group↗