Lyme borreliosis, caused by spirochaetes of the Borrelia burgdorferi genospecies complex, is the most commonly reported tick-borne infection in Europe and North America. The non-specific nature of many of its clinical manifestations presents a diagnostic challenge and concise case definitions are essential for its satisfactory management. Lyme borreliosis is very similar in Europe and North America but the greater variety of genospecies in Europe leads to some important differences in clinical presentation. These new case definitions for European Lyme borreliosis emphasise recognition of clinical manifestations supported by relevant laboratory criteria and may be used in a clinical setting and also for epidemiological investigations.

Lyme disease is very common in southern Sweden, with a relatively high frequency of neurologic complications and arthritis. With the exception of the low incidence of carditis, the pattern of disease we found in Sweden was similar to that reported in the United States.

The main recommendations according to current European case definitions for LB are as follows. Typical erythema migrans should be diagnosed clinically and does not require laboratory testing. The diagnosis of Lyme neuroborreliosis requires laboratory investigation of the spinal fluid including intrathecal antibody production, and the remaining disease manifestations require testing for serum antibodies to B. burgdorferi. Testing individuals with non-specific subjective symptoms is not recommended, because of a low positive predictive value.

The objective of this follow-up study was to determine the long-term outcome of strictly classified cases of neuroborreliosis treated with antibiotics. A 1-y prospective population-based survey of Lyme borreliosis was conducted in southern Sweden between 1992 and 1993. A total of 349 identified cases with suspected neuroborreliosis were followed up 5 y later. Medical records were reviewed and all participants filled in a questionnaire. Of those patients classified with definite neuroborreliosis, 114/130 completed the follow-up, of whom 111 had completed the initial antibiotic treatment. Of the 114 patients followed up, 86 (75%) had recovered completely and 70 (61%) had recovered within 6 months. Residual neurological symptoms, such as facial palsy, concentration disorder, paresthesia and/or neuropathy, were reported by 28/114 patients. No significant differences between different antibiotic treatments were observed in terms of the occurrence of sequelae. To conclude, we found that 25% (95% confidence interval 17-33%) of the patients suffered from residual neurological symptoms 5 y post-treatment. However, the clinical outcome of treated neuroborreliosis is favorable as only 14/114 (12%) patients had sequelae that influenced their daily activities post-treatment. Early diagnosis and treatment would seem to be of great importance in order to avoid such sequelae.

No abstract

Southern Sweden is an area of Lyme borreliosis (LB) endemicity, with an incidence of 69 cases per 100,000 inhabitants. The most frequent clinical manifestations are erythema migrans (77%) and neuroborreliosis (16%). There was no record of human Borrelia strains being isolated from patients in this region before the prospective study reported here. Borrelia spirochetes were isolated from skin and cerebrospinal fluid (CSF) from LB patients living in the region. A total of 39 strains were characterized by OspA serotype analysis, species-specific PCR, and signature nucleotide analysis of the 16S rRNA gene. Of 33 skin isolates, 31 (93.9%) were Borrelia afzelii strains and 2 (6.1%) were Borrelia garinii strains. Of six CSF isolates, five (83.3%) were B. garinii and one (16.7%) was B. afzelii. Neither Borrelia burgdorferi sensu stricto strains nor multiple infections were observed. The B. afzelii isolates were of OspA serotype 2. Three B. garinii strains were of OspA serotype 5, and the remaining four strains were of OspA serotype 6. All of the B. garinii strains belonged to the same 16S ribosomal DNA ribotype class. Our findings agree with earlier findings from other geographic regions in Europe where B. afzelii and B. garinii have been recovered predominately from skin and CSF cultures, respectively. To further study the possible presence in Sweden of the genotype B. burgdorferi sensu stricto, which is known to be present in Europe and to occur predominately in patients with Lyme arthritis, molecular detection of Borrelia-specific DNA in synovial samples from Lyme arthritis patients should be performed.

There are surely scientific, genetic or ecological arguments which show that differences exist between the relapsing fever (RF) spirochaetes and the Lyme borreliosis (LB) group of spirochaetes, both of which belong to the genus Borrelia. In a recent publication, Adeolu and Gupta [1] proposed dividing the genus Borrelia into two genera on the basis of genetic differences revealed by comparative genomics. The new genus name for the LB group of spirochaetes, Borreliella, has subsequently been entered in the GenBank database for some species of the group and in a validation list (List of new names and new combinations previously effectively, but not validly, published) [2]. However, rapidly expanding scientific knowledge and considerable conflicting evidence combined with the adverse consequences of splitting the genus Borrelia make such a drastic step somewhat premature. In our opinion, the basis of this division rests on preliminary evidence and should be rescinded for the following reasons:(1) The proposed split of the genus rests on differences in conserved signature indels (CSI) and conserved signature proteins (CSP) between LB and RF spirochaetes. A major omission in the study published by Adeolu and Gupta [1] is the exclusion of a Borrelia clade containing RF-like species that utilize hard ticks as vectors and reptiles as reservoir hosts [3,4].To identify proteins that are uniquely present in various groups of Borrelia, BLAST searches [5] were performed by Adeolu and Gupta [1] using each protein in the genomes of Borrelia burgdorferi sensu stricto (s.s.) B31 T and Borrelia recurrentis A1 as queries. Out of 1041 and 1390 protein coding genes (i.e. the number of proteins reported in GenBank accession numbers NC_011244 and NC_001318) present in B. recurrentis A1 and B. burgdorferi s.s. B31 T , respectively, 15 CSI (seven for LB, eight for RF) and 25 CSP (21 for LB, four for RF) were found to be unique for the respective groups. However, two of the four CSPs that are apparently unique for the RF group species are not found in all members of this group and therefore do not represent true signature proteins. Hence, just two CSPs and eight CSIs are unique to the RF group.

The Lyme Borrelia genospecies Borrelia afzelii and B. garinii have previously been isolated using a culture method in Swedish patients with Lyme borreliosis (LB). There are reports suggesting that the genospecies distribution in human tissue specimens as determined by molecular methods is different from that obtained by culture. In the present study, we developed a nested PCR for detection of Lyme Borrelia-specific DNA in cerebrospinal fluid from Swedish patients with LB. The genospecies were subsequently identified by sequence analysis in a total of 7 PCR-positive patients. Two sequences were identified as B. burgdorferi sensu stricto (s. s.), 1 as B. afzelii and 4 as B. garinii. These are the first reported cases in which B. burgdorferi s. s. has been shown to be the causative agent of human LB in Sweden. The results of our study confirm that the use of direct molecular analytical methods for Borrelia genospecies identification in clinical specimens can provide epidemiological information additional to that obtained by culture.