[Reinfection with Borrelia burgdorferi in an immunocompetent patient]

Laboratory Diagnosis of Lyme Borreliosis

Lyme borreliosis is caused by a growing list of related, yet distinct, spirochetes with complex biology and sophisticated immune evasion mechanisms. It may result in a range of clinical manifestations involving different organ systems, and can lead to persistent sequelae in a subset of cases. The pathogenesis of Lyme borreliosis is incompletely understood, and laboratory diagnosis, the focus of this review, requires considerable understanding to interpret the results correctly. Direct detection of the infectious agent is usually not possible or practical, necessitating a continued reliance on serologic testing. Still, some important advances have been made in the area of diagnostics, and there are many promising ideas for future assay development. This review summarizes the state of the art in laboratory diagnostics for Lyme borreliosis, provides guidance in test selection and interpretation, and highlights future directions.

Lyme borreliosis

Lyme borreliosis is a multi-organ infection caused by spirochetes of the Borrelia burgdorferi sensu lato group with its species B burgdorferi sensu stricto, Borrelia garinii, and Borrelia afzelii, which are transmitted by ticks of the species Ixodes. Laboratory testing of Lyme borreliosis includes culture, antibody detection using ELISA with whole extracts or recombinant chimeric borrelia proteins, immunoblot, and PCR with different levels of sensitivity and specificity for each test. Common skin manifestations of Lyme borreliosis include erythema migrans, lymphocytoma, and acrodermatitis chronica atrophicans. The last two conditions are usually caused by B garinii and B afzelii, respectively, which are seen more frequently in Europe than in America. Late extracutaneous manifestations of Lyme borreliosis are characterised by carditis, neuroborreliosis, and arthritis. We present evidence-based treatment recommendations for Lyme borreliosis and review the prevention of Lyme borreliosis, including the Lyme vaccines.

Borrelia burgdorferi detected by culture and PCR in clinical relapse of disseminated Lyme borreliosis

A total of 165 patients with disseminated Lyme borreliosis (diagnosed in 1990-94, all seropositive except one culture-positive patient) were followed after antibiotic treatment, and 32 of them were regarded as having a clinically defined treatment failure. Of the 165 patients, 136 were tested by polymerase chain reaction (PCR) during the follow-up. PCR was positive from the plasma of 14 patients 0-30 months after discontinuation of the treatment, and 12 of these patients had a clinical relapse. In addition, Borrelia burgdorferi was cultured from the blood of three patients during the follow-up. All three patients belonged to the group with relapse, and two of them were also PCR positive. This report focuses on the 13 patients with clinical relapse and culture or PCR positivity. Eight of the patients had culture or PCR-proven initial diagnosis, the diagnosis of the remaining five patients was based on positive serology only. All 13 patients were primarily treated for more than 3 months with intravenous and/or oral antibiotics (11 of them received intravenous ceftriaxone, nine for 2 weeks, one for 3 weeks and one for 7 weeks, followed by oral antibiotics). The treatment caused only temporary relief in the symptoms of the patients. All but one of them had negative PCR results immediately after the first treatment. The patients were retreated usually with intravenous ceftriaxone for 4-6 weeks. None of them was PCR positive after the retreatment. The response to retreatment was considered good in nine patients. We conclude that the treatment of Lyme borreliosis with appropriate antibiotics for even more than 3 months may not always eradicate the spirochete. By using PCR, it is possible to avoid unnecessary retreatment of patients with 'post-Lyme syndrome' and those with 'serological scars' remaining detectable for months or years after infection.

Duration of immunity to reinfection with tick-transmitted Borrelia burgdorferi in naturally infected mice

The ability of naturally infected and cured mice to resist reinfection with tick-transmitted Borrelia burgdorferi was tested over a 1-year period. All of the mice were resistant to reinfection when they were challenged at 1.5 months after cure. The majority of animals were resistant to reinfection for up to 10.5 months after cure, but this resistance was lost at 1 year after cure. Both protected and unprotected animals showed a diverse array of antibodies on Western immunoblots. Protection was not associated with the killing of spirochetes in ticks, and naturally infected mice produced no antibodies to outer surface protein A (OSP A). The titers to whole Borrelia sonicate and OSP C, however, remained high throughout the 1-year study period. The levels of borreliacidal antibodies were highest in the 1.5 month-after-cure group. Natural immunity to reinfection with B. burgdorferi is limited in time, is complex, and may involve both humoral and cellular components.

Reinfection in Lyme borreliosis

Two patients with reinfection of Borrelia burgdorferi are presented. An 11-year-old girl developed recurrent acute peripheral facial palsy at an interval of five years. A 64-year-old woman showed paraesthesia in the leg and effusion in the knee. Three years later, an erythema migrans developed at the thigh. In both patients tick bites, corresponding clinical manifestations, and detection of specific antibodies proved the reinfections. The course of the humoral immune responses showed basic differences between the patients. At the interval between the first and second infection, the specific antibodies of the girl decreased beyond the cut-off level. On the other hand, the titer of specific IgG antibodies of the other patient remained at a constant level. Reasons for the failure of immune protection are discussed.

Lyme neuroborreliosis in children

Children are more likely than adults to be bitten by ticks and thus more likely to be infected by Borrelia burgdorferi. In a serosurvey the infection rate measured by immunoglobulin G (IgG) antibodies was 2.6%. In a prospective hospital-based multicentre study 169 children with Lyme neuroborreliosis were examined; the infection was diagnosed by detection of specific immunoglobulin M (IgM) antibodies in the cerebrospinal fluid (CSF) using an IgM capture ELISA. The yearly incidence of Lyme neuroborreliosis was 5.8 cases per 100,000 children aged 1-13. Facial palsy and lymphocytic meningitis account for nearly 90% of all cases with neuroborreliosis indicating striking differences in the clinical spectrum between children and adults. Lyme borreliosis proves to be the most frequently verifiable cause of acute peripheral facial palsy in children, causing every second case of this disorder in the summer and autumn. In cases of facial palsy, nearly all patients with a positive history of tick bite or erythema migrans in the head and neck region show ipsilateral subsequent facial nerve palsy, suggesting a direct invasion via the affected nerve by Borrelia burgdorferi. Lyme borreliosis is the third most frequent cause of lymphocytic meningitis in childhood. Inflammatory changes of the cerebrospinal fluid along with the presence of specific antibodies are mandatory for the diagnosis of Lyme neuroborreliosis. High-dose intravenous penicillin G as well as third-generation cephalosporins prove to be effective in paediatric Lyme neuroborreliosis.