No abstract

Despite rather strict recommendations for antibiotic treatment of disseminated Lyme borreliosis (LB), evidence-based studies on the duration of antibiotic treatment are scarce. The aim of this multicenter study was to determine whether initial treatment with intravenous ceftriaxone (CRO) for 3 weeks should be extended with a period of adjunct oral antibiotic therapy. A total of 152 consecutive patients with LB were randomized in a double-blind fashion to receive either amoxicillin (AMOX) 1 g or placebo (PBO) twice daily for 100 days. Both groups received an initial treatment of intravenous CRO 2 g daily for 3 weeks, followed by the randomized drug or PBO. The outcome was evaluated using the visual analogue scale at the follow-up visits. The final analysis included 145 patients, of whom 73 received AMOX and 72 PBO. Diagnoses of LB were categorized as either definite or possible, on the basis of symptoms, signs, and laboratory results. The diagnosis was definite in 52 of the 73 (71.2%) AMOX-treated patients and in 54 of the 72 (75%) PBO patients. Of the patients with definite diagnoses, 62 had neuroborreliosis, 45 arthritis or other musculoskeletal manifestations, and 4 other manifestations of LB. As judged by the visual analogue scale and patient records, the outcome after a 1-year follow-up period was excellent or good in 114 (78.6%) patients, controversial in 14 (9.7%) patients, and poor in 17 (11.7%) patients. In patients with definite LB, the outcome was excellent or good in 49 (92.5%) AMOX-treated patients and 47 (87.0%) PBO patients and poor in 3 (5.7%) AMOX-treated patients and 6 (11.1%) PBO patients (difference nonsignificant, p = 0.49). Twelve months after the end of intravenous antibiotic therapy, the levels of antibodies against Borrelia burgdorferi were markedly decreased in 50% of the patients with definite LB in both groups. The results indicate that oral adjunct antibiotics are not justified in the treatment of patients with disseminated LB who initially receive intravenous CRO for 3 weeks. The clinical outcome cannot be evaluated at the completion of intravenous antibiotic treatment but rather 6-12 months afterwards. In patients with chronic post-treatment symptoms, persistent positive levels of antibodies do not seem to provide any useful information for further care of the patient.

It has been suggested that a <4-fold decline in the immunoglobulin G (IgG) antibody response to the VlsE sixth invariant region peptide of Borrelia burgdorferi within 6 months after antibiotic treatment may indicate spirochetal persistence in Lyme disease. We studied the response to this peptide in 77 patients with early or late disease, for whom archival samples were available at the time of antibiotic treatment and approximately 6 months or years later. Eight (33%) of the 24 patients with early manifestations and 18 (86%) of the 21 patients with late manifestations had a <4-fold decline in IgG anti-VlsE titers approximately 6 months after successful antibiotic treatment. Of 32 additional patients, 13 (50%) with early manifestations and 5 (83%) with late manifestations still had positive anti-VlsE titers 8-15 years after successful antibiotic treatment. We conclude that persistence of the anti-VlsE antibody response for months or years after antibiotic treatment cannot be equated with spirochetal persistence in Lyme disease.

Lyme borreliosis, an infection caused by the tick-borne spirocheteBorrelia burgdorferi, is a major health problem for populations in areas of endemicity in the Northern Hemisphere. In the present study we assessed the density of ticks and the prevalence ofB. burgdorferi sensu lato among ticks in popular urban recreational areas of Helsinki, Finland. Altogether 1,688 Ixodes ricinus ticks were collected from five areas located within 5 km of the downtown section of Helsinki, and 726 of them (303 nymphs, 189 females, and 234 males) were randomly chosen for laboratory analysis. The midguts of the ticks were divided into three pieces, one for dark-field microscopy, one for cultivation in BSK-II medium, and one for PCR analysis. Ticks were found in all the study areas; their densities varied from 1 to 36 per 100 m along which a cloth was dragged. The rate of tick infection with B. burgdorferi sensu lato varied from 19 to 55%, with the average being 32%. Borellia afzelii was the most predominant genospecies in all the areas, and no B. burgdorferi sensu stricto isolates were detected. Only two ticks were concurrently infected with both B. afzelii and Borrelia garinii. Dark-field microscopy gave more positive results for B. burgdorferi than did cultivation or PCR analysis. However, the agreement between all three methods was fairly good. We conclude that Lyme borreliosis can be contracted even in urban environments not populated with large mammals like deer or elk. The disease should be taken into account in the differential diagnosis of certain symptoms of patients from these areas, and the use of measures to improve the awareness of the general population and health care officials of the risk of contracting the disease is warranted.