Clinical, diagnostic and immunological characteristics of patients with possible neuroborreliosis without intrathecal Ig-synthesis against Borrelia antigen in the cerebrospinal fluid.

The diagnosis of neuroborreliosis is not always straightforward. Intrathecal immunoglobulin (Ig) synthesis against Borrelia antigen may not be detected, at least early in the disease course. Also other neurological and infectious diagnoses have to be considered. We have studied patients with clinical possible neuroborreliosis without intrathecal Ig synthesis against Borrelia antigen in the cerebrospinal fluid (CSF) (n=17). Diagnosis was based on typical clinical history and at least one of the following findings; mononuclear leucocytosis in the CSF (n=4); typical erythema migrans >5 cm in diameter in relation to debut of symptoms (n=8); prompt clinical response to antibiotic teratment (n=14). Also other possible diagnoses had to be excluded. Seventeen patients first investigated because of suspected neuroborreliosis but later confirmed with other diagnoses were used as controls. All patients had a lumbar puncture. Borrelia specific IFN-γ and IL-4 secretion was investigated in peripheral blood (PBL) and CSF with an ELISPOT assay. Polymerase chain reaction (PCR) was used to reveal any Borrelia antigen in the CSF. Six of 17 patients with possible neuroborreliosis showed high IFN-γ secretion in peripheral blood, otherwise we found no statistically significant differences between the groups. PCR did not reveal any Borrelia antigen in CSF. The diagnosis and treatment of possible but not confirmed neuroborreliosis is a clinical challenge. The clinical response to treatment may be the best option in these cases.

Decreased Th1-type inflammatory cytokine expression in the skin is associated with persisting symptoms after treatment of erythema migrans.

BACKGROUND: Despite the good prognosis of erythema migrans (EM), some patients have persisting symptoms of various character and duration post-treatment. Several factors may affect the clinical outcome of EM, e.g. the early interaction between Borrelia (B.) burgdorferi and the host immune response, the B. burgdorferi genotype, antibiotic treatment as well as other clinical circumstances. Our study was designed to determine whether early cytokine expression in the skin and in peripheral blood in patients with EM is associated with the clinical outcome. METHODS: A prospective follow-up study of 109 patients with EM was conducted at the Åland Islands, Finland. Symptoms were evaluated at 3, 6, 12 and 24 months post-treatment. Skin biopsies from the EM and healthy skin were immunohistochemically analysed for expression of interleukin (IL)-4, IL-10, IL-12p70 and interferon (IFN)-γ, as well as for B. burgdorferi DNA. Blood samples were analysed for B. burgdorferi antibodies, allergic predisposition and levels of systemic cytokines. FINDINGS: None of the patients developed late manifestations of Lyme borreliosis. However, at the 6-month follow-up, 7 of 88 patients reported persisting symptoms of diverse character. Compared to asymptomatic patients, these 7 patients showed decreased expression of the Th1-associated cytokine IFN-γ in the EM biopsies (p=0.003). B. afzelii DNA was found in 48%, B. garinii in 15% and B. burgdorferi sensu stricto in 1% of the EM biopsies, and species distribution was the same in patients with and without post-treatment symptoms. The two groups did not differ regarding baseline patient characteristics, B. burgdorferi antibodies, allergic predisposition or systemic cytokine levels. CONCLUSION: Patients with persisting symptoms following an EM show a decreased Th1-type inflammatory response in infected skin early during the infection, which might reflect a dysregulation of the early immune response. This finding supports the importance of an early, local Th1-type response for optimal resolution of LB.

Migrating birds and tickborne encephalitis virus.

During spring and autumn 2001, we screened 13,260 migrating birds at Ottenby Bird Observatory, Sweden, and found 3.4% were infested with ticks. Four birds, each a different passerine species, carried tickborne encephalitis virus (TBEV)-infected ticks (Ixodes ricinus). Migrating birds may play a role in the geographic dispersal of TBEV-infected ticks.

Clinical appearance of erythema migrans caused by Borrelia afzelii and Borrelia garinii--effect of the patient's sex.

AIM: The aim in this survey was to study the clinical characteristics of infections caused by Borrelia genospecies in patients with erythema migrans where borrelial origin was confirmed by polymerase chain reaction. The aim was also to study factors influencing the clinical appearance of erythema migrans. METHODS: The study was conducted in southern Sweden from May 2001 to December 2003 on patients 18 years and older attending with erythema migrans at outpatient clinics. All erythema migrans were verified by polymerase chain reaction, photographed and categorized as "annular" or "non-annular" lesions. A logistic regression model was used to analyze relations between the appearance of the erythema migrans (i.e. annular or non-annular) and factors that influenced its clinical appearance. RESULTS: A total of 118 patients, 54 women (45.8%) and 64 men (54.2%), fulfilled the inclusion criteria. Of these patients, 74% were infected by B. afzelii and 26% by B. garinii (p < 0.001). A total of 45% (38/85) of the erythema migrans were annular, 46% (39/85) were nonannular and 9.4% (8/85) were atypical. For men infected by B. afzelii, the odds ratio of developing non-annular erythema migrans was 0.09 (95% CI: 0.03-0.33) in comparison with women with the same infection. CONCLUSIONS: In this prospective study of a large series of erythema migrans, where infecting genospecies were confirmed by polymerase chain reaction, the sex of patients infected with B. afzelii had a strong influence on the appearance of the rash. Patients infected by B. garinii more often had non-annular erythema migrans and a more virulent infection with more individuals presenting with fever, raised levels of C-reactive protein and seroreactivity in the convalescence sera.

Migratory passerine birds as reservoirs of Lyme borreliosis in Europe.

To define the role of birds as reservoirs and disseminators of Borrelia spirochetes, we characterized tick infestation and reservoir competence of migratory passerine birds in Sweden. A total of 1,120 immature Ixodes ricinus ticks were removed from 13,260 birds and assayed by quantitative polymerase chain reaction (PCR) for Borrelia, followed by DNA sequencing for species and genotype identification. Distributions of ticks on birds were aggregated, presumably because of varying encounters with ticks along migratory routes. Lyme borreliosis spirochetes were detected in 160 (1.4%) ticks. Borrelia garinii was the most common species in PCR-positive samples and included genotypes associated with human infections. Infestation prevalence with infected ticks was 5 times greater among ground-foraging birds than other bird species, but the 2 groups were equally competent in transmitting Borrelia. Migratory passerine birds host epidemiologically important vector ticks and Borrelia species and vary in effectiveness as reservoirs on the basis of their feeding behavior.

Typing of Borrelia relapsing fever group strains.

Partial sequencing of the 16S-23S rDNA intergenic spacer showed two to four genotypes each for Borrelia hermsii and B. turicatae, both relapsing fever agents transmitted by argasid ticks, and for B. miyamotoi and B. lonestari, transmitted by ixodid ticks. Field surveys of Ixodes ticks in Connecticut and Sweden showed limited local diversity for B. miyamotoi.

Sequence typing reveals extensive strain diversity of the Lyme borreliosis agents Borrelia burgdorferi in North America and Borrelia afzelii in Europe.

The genetic polymorphism of Borrelia burgdorferi and Borrelia afzelii, two species that cause Lyme borreliosis, was estimated by sequence typing of four loci: the rrs-rrlA intergenic spacer (IGS) and the outer-membrane-protein gene p66 on the chromosome, and the outer-membrane-protein genes ospA and ospC on plasmids. The major sources of DNA for PCR amplification and sequencing were samples of the B. burgdorferi tick vector Ixodes scapularis, collected at a field site in an endemic region of the north-eastern United States, and the B. afzelii vector Ixodes ricinus, collected at a similar site in southern Sweden. The sequences were compared with those of reference strains and skin biopsy isolates, as well as database sequences. For B. burgdorferi, 10-13 alleles for each of the 4 loci, and a total of 9 distinct clonal lineages with linkage of all 4 loci, were found. For B. afzelii, 2 loci, ospC and IGS, were examined, and 11 IGS genotypes, 12 ospC alleles, and a total of 9 linkage groups were identified. The genetic variants of B. burgdorferi and B. afzelii among samples from the field sites accounted for the greater part of the genetic diversity previously reported from larger areas of the north-eastern United States and central and northern Europe. Although ospC alleles of both species had higher nucleotide diversity than other loci, the ospC locus showed evidence of intragenic recombination and was unsuitable for phylogenetic inference. In contrast, there was no detectable recombination at the IGS locus of B. burgdorferi. Moreover, beyond the signature nucleotides that specified 10 IGS genotypes, there were additional nucleotide polymorphisms that defined a total of 24 subtypes. Maximum-likelihood and parsimony cladograms of B. burgdorferi aligned IGS sequences revealed the subtype sequences to be terminal branches of clades, and the existence of at least three monophyletic lineages within B. burgdorferi. It is concluded that B. burgdorferi and B. afzelii have greater genetic diversity than had previously been estimated, and that the IGS locus alone is sufficient for strain typing and phylogenetic studies.

Determination of novel Borrelia genospecies in Swedish Ixodes ricinus ticks.

A total of 301 adult questing Ixodes ricinus ticks were collected at 15 different locations along the south and east coasts of Sweden to determine the Borrelia genospecies diversity. Thirty-two ticks (11%) were found to be positive by nested PCR with Borrelia burgdorferi sensu lato-specific primers. Species determination was based on partial sequencing of the 16S rRNA gene and the flagellin gene. Five different Borrelia species were found. The nucleotide sequence of the Borrelia DNA found in two ticks differed extensively from the nucleotide sequences of the Borrelia DNA found in the other ticks, and analysis revealed that they were closely related to the relapsing fever borrelia species Borrelia miyamotoi. This is the first report of a B. miyamotoi-like borrelia in I. ricinus and in Europe. Moreover, the Borrelia DNA of two ticks (6%) clustered within the B. valaisiana complex. B. valaisiana has not previously been reported in Sweden. B. afzelii DNA was found in 14 ticks (44%), and B. garinii DNA was found in 10 ticks (31%). B. burgdorferi sensu stricto DNA was found in four ticks (13%). We conclude that all of the known human-pathogenic species (B. garinii, B. afzelii, and B. burgdorferi sensu stricto) and B. valaisiana found elsewhere in Europe are also present in the Swedish host-seeking tick population and that a B. miyamotoi-like Borrelia species seems to be present in I. ricinus ticks in Europe.