Cytokine responses of immunosuppressed and immunocompetent patients with Neoehrlichia mikurensis infection.

PURPOSE: The tick-borne bacterium Neoehrlichia mikurensis causes the infectious disease neoehrlichiosis in humans. Vascular endothelium is one of the target cells of the infection. Neoehrlichiosis patients with compromised B cell immunity present with more severe inflammation than immunocompetent patients. The aim of this study was to compare the cytokine profiles of immunocompetent and immunosuppressed patients with neoehrlichiosis. METHODS: Blood samples from Swedish and Norwegian immunosuppressed (N = 30) and immunocompetent (N = 16) patients with neoehrlichiosis were analyzed for the levels of 30 cytokines, using a multiplex cytokine assay and ELISA. A gender-matched healthy control group (N = 14) was analyzed in parallel. Data were analyzed using the multivariate method OPLS-DA. RESULTS: The multiplex cytokine analyses generated more cytokine results than did the uniplex ELISA analyses. Multivariate analysis of the multiplex cytokine results established that increased levels of FGF2, GM-CSF, CXCL10, and IFN-γ were associated with immunosuppressed patients, whereas increased levels of IL-15 and VEGF were associated with immunocompetent neoehrlichiosis patients. When multivariate analysis findings were confirmed with uniplex ELISA, it was found that both groups of patients had similarly elevated levels of VEGF, FGF2 and IFN-γ. In contrast, the immunosuppressed patients had clearly elevated levels of CXCL10, CXCL13 and BAFF, whereas the immunocompetent patients had the same levels as healthy controls. CONCLUSION: Pro-angiogenic and type 1 cytokines were produced as part of the host response of neoehrlichiosis independent of immune status, whereas immunosuppressed neoehrlichiosis patients produced cytokines required for B cell-mediated defense.

Cerebrospinal fluid markers of inflammation and brain injury in Lyme neuroborreliosis - a prospective follow-up study.

OBJECTIVES: The purpose of this study was to evaluate levels and kinetics of cerebrospinal fluid (CSF) markers of inflammation and brain injury in patients with Lyme neuroborreliosis (LNB). METHODS: Adult patients with clinically suspected LNB were enrolled, in a prospective clinical study in the South East of Sweden. Patients were classified according to the European Federation of Neurological Societies' guidelines. Definite cases of LNB were re-examined one month later including a repeat CSF investigation. Routine laboratory parameters were investigated along with CSF levels of neurodegenerative markers glial fibrillary acidic protein (GFAp), total tau (t-tau) and neurofilament light protein (NFL), as well as neuroinflammatory markers soluble triggering receptor expressed on myeloid cells 2 (sTREM2), YKL-40 and CXCL13. Non-LNB served as controls. An additional comparison group consisted of spinal anesthesia subjects (SAS) without known central nervous system conditions. RESULTS: CSF levels of sTREM2 and CXCL13 were elevated in definite LNB patients at diagnosis compared with non-LNB patients (p<0.001) and SAS (p≤0.01). In addition, CSF levels of sTREM2, YKL-40 and CXCL13 rapidly declined in at follow-up after antibiotic treatment. In contrast, CSF levels of GFAp and t-tau did not differ across LNB groups, and did not change after treatment. CONCLUSIONS: Although in a limited number of LNB patients, the results indicate a predominance of microglial and neuroinflammatory involvement rather than parenchymal CNS injury in CSF at diagnosis of LNB with a prompt decline after antibiotic treatment. The findings provide pathogenetic insights and may be of value in differential diagnosis of CSF findings.

Intrathecal Th17- and B cell-associated cytokine and chemokine responses in relation to clinical outcome in Lyme neuroborreliosis: a large retrospective study.

BACKGROUND: B cell immunity, including the chemokine CXCL13, has an established role in Lyme neuroborreliosis, and also, T helper (Th) 17 immunity, including IL-17A, has recently been implicated. METHODS: We analysed a set of cytokines and chemokines associated with B cell and Th17 immunity in cerebrospinal fluid and serum from clinically well-characterized patients with definite Lyme neuroborreliosis (group 1, n = 49), defined by both cerebrospinal fluid pleocytosis and Borrelia-specific antibodies in cerebrospinal fluid and from two groups with possible Lyme neuroborreliosis, showing either pleocytosis (group 2, n = 14) or Borrelia-specific antibodies in cerebrospinal fluid (group 3, n = 14). A non-Lyme neuroborreliosis reference group consisted of 88 patients lacking pleocytosis and Borrelia-specific antibodies in serum and cerebrospinal fluid. RESULTS: Cerebrospinal fluid levels of B cell-associated markers (CXCL13, APRIL and BAFF) were significantly elevated in groups 1, 2 and 3 compared with the reference group, except for BAFF, which was not elevated in group 3. Regarding Th17-associated markers (IL-17A, CXCL1 and CCL20), CCL20 in cerebrospinal fluid was significantly elevated in groups 1, 2 and 3 compared with the reference group, while IL-17A and CXCL1 were elevated in group 1. Patients with time of recovery <3 months had lower cerebrospinal fluid levels of IL-17A, APRIL and BAFF compared to patients with recovery >3 months. CONCLUSIONS: By using a set of markers in addition to CXCL13 and IL-17A, we confirm that B cell- and Th17-associated immune responses are involved in Lyme neuroborreliosis pathogenesis with different patterns in subgroups. Furthermore, IL-17A, APRIL and BAFF may be associated with time to recovery after treatment.

Human Tick-Borne Encephalitis and Characterization of Virus from Biting Tick.

We report a case of human tick-borne encephalitis (TBE) in which the TBE virus was isolated from the biting tick. Viral growth and sequence were characterized and compared with those of a reference strain. Virus isolation from ticks from patients with TBE may offer a new approach for studies of epidemiology and pathogenicity.

Infections with Candidatus Neoehrlichia mikurensis and Cytokine Responses in 2 Persons Bitten by Ticks, Sweden.

The prevalence of Candidatus Neoehrlichia mikurensis infection was determined in 102 persons bitten by ticks in Sweden. Two infected women had erythematous rashes; 1 was co-infected with a Borrelia sp., and the other showed seroconversion for Anaplasma phagocytophilum. Both patients had increased levels of Neoehrlichia DNA and serum cytokines for several months.

How to Detect Antibodies Against Babesia divergens in Human Blood Samples.

Background: Today only indirect fluorescent antibody assays (IFAs) are commercially available to detect antibodies against Babesia divergens in humans. IFA is subjective and requires highly experienced staff. We have therefore developed an enzyme-linked immunosorbent assay (ELISA)-based method for measuring anti-B. divergens immunoglobulin G antibodies in human blood samples. Methods: Crude merozoite extract from in vitro cultures of a new B. divergens isolate was used in ELISA to detect antibodies in different sets of samples: Borrelia burgdorferi-positive samples, healthy individuals, tick-bitten individuals including follow-up samples 3 months later, positive control samples from patients with an active Babesia infection, and samples from malaria-endemic regions. As a reference, IFA was used to detect antibodies in the tick-bitten samples. Western blot was used to evaluate reactions against specific bands in extracts with/without parasites. Results: Using IFA as the reference method, the sensitivity and specificity of the ELISA were 86% (12/14) and 100% (52/52). There was a very high correlation (r = -0.84; P = .0004) between IFA dilution factors and ELISA absorbances among the samples classified as positive. Five percent of the B. burgdorferi-positive samples were judged as weakly positive and 5% as strongly positive in our ELISA. Western blot showed that the immunodominant antigens (∼120 kDa) were from merozoites and not from erythrocytes. Conclusions: This ELISA can detect antibodies directed against B. divergens, and it can be a useful and easy assay to handle compared with IFA. The ELISA can also measure high and low levels of antibodies, which could give insight into the recency of a B. divergens infection.

Intrathecal Th17-driven inflammation is associated with prolonged post-treatment convalescence for patients with Lyme neuroborreliosis.

Lyme neuroborreliosis (LNB) is associated with increased levels of pro-inflammatory cytokines and chemokines in the cerebrospinal fluid (CSF). Residual symptoms after antibiotic treatment can have deleterious effects on patients and knowledge regarding the pathogenesis linked to prolonged recovery is lacking. In this prospective follow-up study, we investigated the B cell-associated and T helper (Th) cell-associated immune responses in well-characterized patients with LNB and controls. The aims were to assess the kinetics of selected cytokines and chemokines involved in the inflammatory response and to identify potential prognostic markers. We investigated 13 patients with LNB according to a standardized clinical protocol before antibiotic treatment and after 1, 6 and 12 months of follow-up. CSF and blood samples were obtained at baseline and after 1 month. As controls, we used CSF samples from 37 patients who received spinal anesthesia during orthopedic surgery. The CSF samples were analyzed for CXCL10 (Th1-related), CCL22 (Th2-related) and IL-17A, CXCL1 and CCL20 (Th17-related), as well as for the B cell-related cytokines of a proliferation-inducing ligand (APRIL), B cell-activating factor (BAFF) and CXCL13. The CSF levels of all the cytokines and chemokines, with the exception of APRIL, were significantly higher at baseline in patients with LNB compared with controls. All the cytokines and chemokines, except for IL-17A were significantly reduced at 1-month follow-up. Patients with quick recovery (< 1 month, n = 3) had significantly lower levels of CCL20 at baseline and lower levels of IL-17A at 1-month follow-up. Patients with time of recovery > 6 months (n = 7) had significantly higher levels of IL-17A at the one-month follow-up. No other cytokines or chemokines were associated with prolonged recovery. Dominating residual symptoms were fatigue, myalgia, radiculitis and/or arthralgia. In this prospective follow-up study of patients with LNB, we found significantly lower levels of CCL20 in those who recovered rapidly, and increased levels of IL-17A in patients with delayed recovery post-treatment. Our findings indicate persistent Th17-driven inflammation in the CSF, possibly contributing to a longer convalescence, and suggest IL-17A and CCL20 as potential biomarker candidates for patients with LNB.

The AxBioTick Study: Borrelia Species and Tick-Borne Encephalitis Virus in Ticks, and Clinical Responses in Tick-Bitten Individuals on the Aland Islands, Finland.

The AxBioTick study was initiated to investigate the prevalence of ticks and tick-borne pathogens and their impact on antibody and clinical responses in tick-bitten individuals on the Aland Islands. This geographical area is hyperendemic for both Lyme borreliosis (LB) and Tick-borne encephalitis (TBE). Blood samples and ticks were collected from 100 tick-bitten volunteers. A total of 425 ticks was collected, all determined to Ixodes ricinus using molecular tools. Of them 20% contained Borrelia species, of which B. garinii and B. afzelii were most common. None contained the TBE virus (TBEV). Blood samples were drawn in conjunction with the tick bite, and eight weeks later. Sera were analyzed for Borrelia- and TBEV-specific antibodies using an ELISA and a semiquantitative antibody assay. In total 14% seroconverted in Borrelia C6IgG1, 3% in TBEV IgG, and 2% in TBEV IgM. Five participants developed clinical manifestations of LB. The high seroprevalence of both Borrelia (57%) and TBEV (52%) antibodies are likely attributed to the endemic status of the corresponding infections as well as the TBE vaccination program. Despite the similar prevalence of Borrelia spp. detected in ticks in other parts of Europe, the infection rate in this population is high. The AxBioTick study is continuing to investigate more participants and ticks for co-infections, and to characterize the dermal immune response following a tick bite.

Doxycycline-mediated effects on persistent symptoms and systemic cytokine responses post-neuroborreliosis: a randomized, prospective, cross-over study.

BACKGROUND: Persistent symptoms after treatment of neuroborreliosis (NB) are well-documented, although the causative mechanisms are mainly unknown. The effect of repeated antibiotic treatment has not been studied in detail. The aim of this study was to determine whether: (1) persistent symptoms improve with doxycycline treatment; (2) doxycycline has an influence on systemic cytokine responses, and; (3) improvement of symptoms could be due to doxycycline-mediated immunomodulation. METHODS/DESIGN: 15 NB patients with persistent symptoms ≥6 months post-treatment were double-blindly randomized to receive 200 mg of doxycycline or a placebo for three weeks. After a six-week wash-out period, a cross-over with a three-week course of a placebo or doxycycline was conducted. The primary outcome measures were improvement of persistent symptoms assessed by neurological examinations, a symptom severity score and estimation of the quality of life. The secondary outcome measure was changes in systemic cytokine responses. RESULTS: All 15 patients finished the study. No doxycycline-mediated improvement of post-treatment symptoms or quality of life was observed. Nor could any doxycycline-mediated changes in systemic cytokine responses be detected. The study was completed without any serious adverse events. DISCUSSION: No doxycycline-mediated improvement of post-treatment symptoms or quality of life was observed. Nor could any doxycycline-mediated changes in systemic cytokine responses be detected. The study was completed without any serious adverse events. To conclude, in this pilot study, doxycycline-treatment did not lead to any improvement of either the persistent symptoms or quality of life in post-NB patients. Accordingly, doxycycline does not seem to be the optimal treatment of diverse persistent symptoms post-NB. However, the results need to be confirmed in larger studies. TRIAL REGISTRATION: NCT01205464 (clinicaltrials.gov).

Adaptive and innate immune responsiveness to Borrelia burgdorferi sensu lato in exposed asymptomatic children and children with previous clinical Lyme borreliosis.

Why some individuals develop clinical manifestations in Lyme borreliosis (LB) while others remain asymptomatic is largely unknown. Therefore, we wanted to investigate adaptive and innate immune responsiveness to Borrelia burgdorferi sensu lato in exposed Borrelia-antibody-positive asymptomatic children (n = 20), children with previous clinical LB (n = 24), and controls (n = 20). Blood samples were analyzed for Borrelia-specific interferon (IFN)-γ, interleukin (IL)-4, and IL-17 secretion by ELISPOT and Borrelia-induced IL-1ß, IL-6, IL-10, IL-12(p70), and tumor necrosis factor (TNF) secretion by Luminex. We found no significant differences in cytokine secretion between groups, but a tendency towards an increased spontaneous secretion of IL-6 was found among children with previous clinical LB. In conclusion, the adaptive or innate immune responsiveness to Borrelia burgdorferi sensu lato was similar in Borrelia-exposed asymptomatic children and children with previous clinical LB. Thus, the immunological mechanisms of importance for eradicating the spirochete effectively without developing clinical manifestations of LB remain unknown.

Indications of Th1 and Th17 responses in cerebrospinal fluid from patients with Lyme neuroborreliosis: a large retrospective study.

BACKGROUND: Previous studies indicate that successful resolution of Lyme neuroborreliosis (NB) is associated with a strong T helper (Th) 1-type cytokine response in the cerebrospinal fluid (CSF) followed by a down-regulating Th2 response, whereas the role of the recently discovered Th17 cytokine response is unknown. METHODS: To investigate the relative contribution of different Th associated cytokine/chemokine responses, we used a multiple bead array to measure the levels of CXCL10 (Th1 marker), CCL22 (Th2 marker), IL-17 (Th17 marker) and CXCL8 (general inflammation marker), in serum and in CSF from untreated patients with confirmed NB (n = 133), and non-NB patients (n = 96), and related the findings to clinical data. Samples from patients with possible early NB (n = 15) and possible late NB (n = 19) were also analysed, as well as samples from an additional control group with orthopaedic patients (n = 17), where CSF was obtained at spinal anaesthesia. RESULTS: The most prominent differences across groups were found in the CSF. IL-17 was elevated in CSF in 49% of the patients with confirmed NB, but was not detectable in the other groups. Patients with confirmed NB and possible early NB had significantly higher CSF levels of CXCL10, CCL22 and CXCL8 compared to both the non-NB group and the control group (p < 0.0001 for all comparisons). Patients in the early NB group, showing a short duration of symptoms, had lower CCL22 levels in CSF than did the confirmed NB group (p < 0.0001). Furthermore, patients within the confirmed NB group showing a duration of symptoms <2 weeks, tended to have lower CCL22 levels in CSF than did those with longer symptom duration (p = 0.023). Cytokine/chemokine levels were not correlated with clinical parameters or to levels of anti-Borrelia-antibodies. CONCLUSION: Our results support the notion that early NB is dominated by a Th1-type response, eventually accompanied by a Th2 response. Interestingly, IL-17 was increased exclusively in CSF from patients with confirmed NB, suggesting a hitherto unknown role for Th17 in NB. However, for conclusive evidence, future prospective studies are needed.

Three Babesia species in Ixodes ricinus ticks from migratory birds in Sweden.

BACKGROUND: Migratory birds can cross geographical and environmental barriers and are thereby able to facilitate transmission of tick-borne pathogens both as carriers of infected ticks and as reservoirs of pathogenic microorganisms. Ixodes ricinus is one of the most abundant tick species in the Northern Hemisphere and a main vector of several Babesia species, some which pose a potential threat to human and animal health. At present only two cases of overt babesiosis in humans have so far been reported in Sweden. To better understand the potential role of birds as disseminators of zoonotic Babesia protozoan parasites, we investigated the presence of Babesia species in ticks removed from migratory birds. METHODS: Ticks were collected from birds captured at Ottenby Bird Observatory, south-eastern Sweden, from March to November 2009. Ticks were molecularly identified to species, and morphologically to developmental stage, and the presence of Babesia protozoan parasites was determined by real-time PCR. RESULTS: In total, 4601 migratory birds of 65 species were examined for tick infestation. Ticks removed from these birds have previously been investigated for the presence of Borrelia bacteria and the tick-borne encephalitis virus. In the present study, a total of 1102 ticks were available for molecular analysis of Babesia protozoan parasites. We found that 2.4% of the ticks examined, all I. ricinus, were positive for mammal-associated Babesia species. Out of all Babesia-positive samples, Babesia venatorum was the most prevalent (58%) species, followed by Babesia microti (38%) and Babesia capreoli (4.0%). B. venatorum and B. capreoli were detected in I. ricinus larvae, whereas B. microti was only present in I. ricinus nymphs. This supports the view that the two first-mentioned species are vertically (transovarially) transmitted in the tick population, in contrast to B. microti. The largest number of Babesia-infected ticks was removed from the common redstart (Phoenicurus phoenicurus) and European robin (Erithacus rubecula). CONCLUSIONS: This study reveals that Babesia protozoan parasites are present in ticks infesting migratory birds in south-eastern Sweden, which could potentially lead to the dissemination of these tick-borne microorganisms into new areas, thus posing a threat to humans and other mammals.

Laboratory Methods for Detection of Infectious Agents and Serological Response in Humans With Tick-Borne Infections: A Systematic Review of Evaluations Based on Clinical Patient Samples.

Background: For the most important and well-known infections spread by Ixodes ticks, Lyme borreliosis (LB) and tick-borne encephalitis (TBE), there are recommendations for diagnosis and management available from several health authorities and professional medical networks. However, other tick-borne microorganisms with potential to cause human disease are less known and clear recommendations on diagnosis and management are scarce. Therefore, we performed a systematic review of published studies and reviews focusing on evaluation of laboratory methods for clinical diagnosis of human tick-borne diseases (TBDs), other than acute LB and TBE. The specific aim was to evaluate the scientific support for laboratory diagnosis of human granulocytic anaplasmosis, rickettsiosis, neoehrlichiosis, babesiosis, hard tick relapsing fever, tularemia and bartonellosis, as well as tick-borne co-infections and persistent LB in spite of recommended standard antibiotic treatment. Methods: We performed a systematic literature search in 11 databases for research published from 2007 through 2017, and categorized potentially relevant references according to the predefined infections and study design. An expert group assessed the relevance and eligibility and reviewed the articles according to the QUADAS (diagnostic studies) or AMSTAR (systematic reviews) protocols, respectively. Clinical evaluations of one or several diagnostic tests and systematic reviews were included. Case reports, non-human studies and articles published in other languages than English were excluded. Results: A total of 48 studies fulfilled the inclusion criteria for evaluation. The majority of these studies were based on small sample sizes. There were no eligible studies for evaluation of tick-borne co-infections or for persistent LB after antibiotic treatment. Conclusions: Our findings highlight the need for larger evaluations of laboratory tests using clinical samples from well-defined cases taken at different time-points during the course of the diseases. Since the diseases occur at a relatively low frequency, single-center cross-sectional studies are practically not feasible, but multi-center case control studies could be a way forward.

Prevalence and diversity of Borrelia species in ticks that have bitten humans in Sweden.

Members of the genus Borrelia are among the most common infectious agents causing tick-borne disease in humans worldwide. Here, we developed a Light Upon eXtension (LUX) real-time PCR assay that can detect and quantify Borrelia species in ticks that have fed on humans, and we applied the assay to 399 such ticks. Borrelia PCR-positive ticks were identified to species level by sequencing the products of conventional PCR performed using Borrelia group-specific primers. There was a 19% prevalence of Borrelia spp. in the detached ticks, and the number of spirochetes per Borrelia PCR-positive tick ranged from 2.0 × 10(2) to 4.9 × 10(5), with a median of 7.8 × 10(3) spirochetes. Adult ticks had a significantly larger number of spirochetes, with a median of 8.4 × 10(3) compared to the median of nymphs of 4.4 × 10(3). [corrected] Adult ticks also exhibited a higher prevalence of Borrelia (33%) than nymphs (14%). Among the identified species, Borrelia afzelii was found to predominate (61%) and was followed by B. garinii (23%), B. valaisiana (13%), B. burgdorferi sensu stricto (1%), B. lusitaniae (1%), and B. miyamotoi-like (1%). Also, 3% of the ticks were coinfected with multiple strains of B. afzelii. Notably, this is the first report of B. lusitaniae being detected in ticks in Sweden. Our LUX real-time PCR assay proved to be more sensitive than a corresponding TaqMan assay. In conclusion, the novel LUX real-time PCR method is a rapid and sensitive tool for detection and quantification of Borrelia spp. in ticks.

Mapping of hormones and cortisol responses in patients after Lyme neuroborreliosis.

BACKGROUND: Persistent symptoms after treatment for neuroborreliosis are common for reasons mainly unknown. These symptoms are often unspecific and could be caused by dysfunctions in endocrine systems, an issue that has not been previously addressed systematically. We therefore mapped hormone levels in patients with previous confirmed Lyme neuroborreliosis of different outcomes and compared them with a healthy control group. METHODS: Twenty patients of a retrospective cohort of patients treated for definite Lyme neuroborreliosis were recruited 2.3 to 3.7 years (median 2.7) after diagnosis, together with 23 healthy controls. Lyme neuroborreliosis patients were stratified into two groups according to a symptom/sign score. All participants underwent anthropometric and physiological investigation as well as an extensive biochemical endocrine investigation including a short high-dose adrenocorticotropic hormone stimulation (Synacthen) test. In addition to hormonal status, we also examined electrolytes, 25-hydroxy-vitamin D and interleukin-6. RESULTS: Eight patients (40%) had pronounced symptoms 2-3 years after treatment. This group had a higher cortisol response to synacthen as compared with both controls and the Lyme neuroborreliosis patients without remaining symptoms (p < 0.001 for both comparisons). No other significant differences in the various baseline biochemical parameters, anthropometric or physiological data could be detected across groups. CONCLUSIONS: Apart from a positive association between the occurrence of long-lasting complaints after Lyme neuroborreliosis and cortisol response to synacthen, no corticotropic insufficiency or other serious hormonal dysfunction was found to be associated with remaining symptoms after treatment for Lyme neuroborreliosis.

Emerging tick-borne pathogens in the Nordic countries: A clinical and laboratory follow-up study of high-risk tick-bitten individuals.

Despite the presence of several microorganisms, other than Borrelia burgdorferi sensu lato (Bbsl) and TBE virus, in Ixodes ricinus ticks from the Nordic countries, data is lacking on their pathogenic potential in humans. In this study, we wanted to investigate the aetiology and clinical manifestations of tick-transmitted infections in individuals seeking medical care following a tick-bite. The sampling frame was participants of a large-scale, prospective, multi-centre, follow-up study of tick-bitten volunteers recruited in Sweden, Finland and Norway in the years 2007-2015. Participants who sought medical care during the three-month follow-up period and from whom blood samples were collected during this healthcare visit (n = 92) were tested, using PCR, for exposure to spotted fever group (SFG) Rickettsia spp., Anaplasma phagocytophilum and Babesia spp. Moreover, 86 of these individuals had two serum samples, collected three months apart, tested serologically for six tick-borne microorganisms. The selected organisms - Bbsl, SFG rickettsiae, Anaplasma phagocytophilum, TBE virus, Babesia microti and Bartonella henselae - have all been detected in field-collected ticks from the Nordic countries. Medical records were reviewed and questionnaires were completed to determine clinical manifestations. We found Lyme borreliosis to be the most common tick-transmitted infection as seen in 46 (54%) of the 86 participants with available medical records. Among the 86 participants with paired sera, serological or molecular evidence of recent exposure to other microorganisms than Bbsl could be demonstrated in eight (9%). Five participants (6%) exhibited serological evidence of recent concomitant exposure to more than one tick-borne microorganism. Clinical presentations were mild with one exception (TBE). In conclusion, our data suggest a low risk of infection with tick-borne microorganisms, other than Bbsl, in immunocompetent tick-bitten persons from the examined regions, a low occurrence of co-infection and mostly mild or no overt clinical signs of infection in immunocompetent persons exposed to the studied agents.

Antibody responses to borrelia IR(6) peptide variants and the C6 peptide in Swedish patients with erythema migrans.

The aim of this study was to evaluate the antibody responses to different VlsE protein IR(6) peptide variants and the synthetic C6 peptide in acute and convalescent (2-3 and 6 months) serum samples from Swedish patients with clinical erythema migrans (EM). Serum samples were prospectively collected from 148 patients with EM and compared to serum samples obtained from 200 healthy blood donors. The IgG responses to 3 IR(6) peptide variants originating from Borrelia burgdorferi (B. burgdorferi) sensu stricto, B. garinii, and B. afzelii were measured by enzyme-linked immunosorbent assays (ELISAs) and compared to a commercial C6 peptide ELISA. Seropositivity rate in the IR(6) or C6 peptide ELISAs ranged from 32% to 58% at presentation, 30-52% after 2-3 months, and 20-36% after 6 months. At presentation, positive antibodies in any of the 4 ELISAs were found in 66%. In 7/52 (13%), C6-negative EM cases, serological reaction was found to the B. burgdorferi sensu stricto-derived IR(6) peptide. In patients reporting previous LB compared to those without previous LB, significantly higher seropositivity rates were noted for all IR(6) peptides, but not for the C6 peptide. In the serology of EM in Europe, C6 ELISA does not seem to cover all cases. An ELISA using a mixture of B. burgdorferi sensu stricto IR(6) peptide and the C6 peptide could be of value in the serodiagnosis of LB in Europe. Further studies on combinations of variant IR(6) peptides and the C6 peptide in other manifestations of LB are needed to address this issue.

The Tick-Borne Diseases STING study: Real-time PCR analysis of three emerging tick-borne pathogens in ticks that have bitten humans in different regions of Sweden and the Aland islands, Finland.

A milder climate has during the last decade contributed to an increased density and spreading of ixodid ticks, thus enhancing their role as emerging vectors for pathogenic microorganisms in northern Europe. It remains unclear if they contribute to the occurrence of infections caused by the bacteria Bartonella spp., Francisella tularensis subspecies holarctica and the parasite Toxoplasma gondii in Sweden and on the Åland islands, Finland. In this study, we want to improve understanding of the tick-borne transmission of these pathogens. Volunteers were recruited at primary healthcare centers. Ticks and blood samples were acquired from participants recruited in 2008 and 2009. Health questionnaires were completed, and medical records were acquired where applicable. Feeding time was estimated and screening of pathogens in the ticks was performed through real-time PCR. Ticks (n = 1849) were of mixed developmental stages: 76 larvae, 1295 nymphs, 426 adults and 52 undetermined. All analyzed ticks were considered negative for these pathogens since the CT-values were all below the detection limit for Bartonella spp. (1663 ticks), Francisella spp. (1849 ticks) and Toxoplasma gondii (1813 ticks). We assume that infections with these pathogens are caused by other transmission pathways within these regions of Sweden and the Åland islands, Finland.

Lyme neuroborreliosis in children: a prospective study of clinical features, prognosis, and outcome.

BACKGROUND: Evaluation of children with clinically suspected neuroborreliosis (NB) is difficult. With a prospective study design we wanted to characterize children with signs and symptoms indicative for NB, investigate clinical outcome and, if possible, identify factors of importance for recovery. MATERIAL/METHODS: Children being evaluated for NB (n = 177) in southeast Sweden were categorized into 3 groups: "confirmed neuroborreliosis" (41%) with Borrelia antibodies in the cerebrospinal fluid, "possible neuroborreliosis" (26%) with pleocytosis but no Borrelia antibodies in the cerebrospinal fluid, and "not determined" (33%) with no pleocytosis and no Borrelia antibodies in the cerebrospinal fluid. Antibiotic treatment was given to 69% of children. Patients were followed during 6 months and compared with a matched control group (n = 174). RESULTS: Clinical recovery at the 6-month follow-up (n = 177) was generally good and no patient was found to have recurrent or progressive neurologic symptoms. However, persistent facial nerve palsy caused dysfunctional and cosmetic problems in 11% of patients. Persistent nonspecific symptoms, such as headache and fatigue, were not more frequently reported in patients than in controls. Influence on daily life was reported to the same extent in patients and controls. Consequently, persistent headache and fatigue at follow-up should not be considered as attributable to NB. No prognostic factors could be identified. CONCLUSIONS: Clinical recovery was satisfactory in children being evaluated for NB although persistent symptoms from facial nerve palsy occurred. Persistent nonspecific symptoms, such as headache and fatigue, were not more frequently reported in patients than in controls.

C6-peptide serology as diagnostic tool in neuroborreliosis.

The aim of this study was to evaluate the usefulness of borrelia serology (Quick ELISA C6 Borrelia assay kit) as a diagnostic tool in cases of suspected neuroborreliosis. A retrospective patient material consisting of 124 paired serum and cerebrospinal fluid samples with a positive anti-borrelia antibody index (AI) using the IDEIA Lyme Neuroborreliosis test was compared with 124 AI-negative matched control subjects. The patients were divided into four groups based on presence of pleocytosis and age above or below 12 years. The presence of positive C6 serology in AI-positive patients with pleocytosis was 89% (83/93), significantly different (p<0.01) from in patients without pleocytosis (58%, 18/31). In AI-positive patients aged > or =12 years with pleocytosis, 94% (51/54) had a positive C6 serology. Of AI-positive patients with a symptom duration of more than 30 days, 93% (27/29) were positive by the C6 test. We conclude that the C6 serum test, together with clinical evaluation, is a powerful diagnostic tool in adult (> or =12 years) European patients with suspected neuroborreliosis with a symptom duration of more than 30 days. Patients with suspected neuroborreliosis and positive C6 results should be further investigated by lumbar puncture for definite diagnosis.