Impact of strain heterogeneity on Lyme disease serology in Europe: comparison of enzyme-linked immunosorbent assays using different species of Borrelia burgdorferi sensu lato

Knowledge, Attitudes, and Behaviors Regarding Lyme Borreliosis Prevention in the Endemic Area of Northeastern Poland

(1) Background: The incidence of Lyme borreliosis (LB) is increasing in Europe. The new LB vaccine is still in clinical development, thus the dissemination of knowledge about the disease is essential. We assessed the knowledge, attitudes and preventive practices (KAP) against tick-borne diseases (TBDs) of people living in the endemic area in northeastern Poland. (2) Methods: We surveyed 406 adults using a 37-item anonymous paper survey. The data were analyzed with regression models. (3) Results: The two most popular knowledge sources were the Internet and doctors, selected by 77.8% and 53.4%, respectively. Respondents felt moderately knowledgeable about TBDs and tick bite prophylaxis (median scores 5/10, and 6/10, respectively), considered TBDs to be a significant health threat (median 8/10), attributed high risk to tick mouthparts remaining in the skin after tick removal (median 10/10), and shared multiple misconceptions regarding LB transmission, symptoms, and management. General knowledge scores (GKS) about TBDs and tick protection practices scores (TPS) were moderate (65.0%; IQR, 55.8−71.7%, 63.6%; 54.5−72.7%, respectively). Only 48.0% had a positive attitude towards TBE vaccination. A recent tick-bite was associated with higher GKS (OR, 2.55; 95% CI, 1.27−5.10; p = 0.008), higher TPS (OR 4.76, 95% CI, 2.0−11.1; p < 0.001), and a positive attitude towards TBE vaccine (OR 2.10, 1.07−4.10, p = 0.030). A positive vaccine attitude was also associated with obtaining TBD knowledge from doctors and other verified sources (OR, 2.654, 1.66−4.23; p < 0.001). Age, place of residence, and frequent exposure to ticks in green areas were not associated with GKS, TPS, nor vaccine attitude. (4) Conclusions: Increased risk perceptions are associated with adoption of behaviors preventing TBDs. Medical professionals play an important role in communicating knowledge about TBDs. There is a need to revise current communication strategies with respect to tick bites and prevention of LB and other TBDs.

Innate and Th1/Th17 adaptive immunity in acute and convalescent Brazilian borreliosis disease

Introduction

Brazilian borreliosis (BB) disease is an infectious disease transmitted by ticks that mimics Lyme disease (LD) from the Northern Hemisphere. The BB clinical picture is characterized by a pathognomonic skin lesion (migratory erythema) and joint, neurological, cardiac and psychiatric symptoms. Innate and Th1/Th17 adaptive immunity seem to play an important role in the pathogenesis of Lyme disease.

Objective

The aim of this study was to characterize the role of innate and Th1/Th17 adaptive immunity in BB patients with acute (<3 months) and convalescent (>3 months) disease.

Methods

Fifty BB patients (28 with acute and 22 with convalescent disease) without treatment and 30 healthy subjects were evaluated. Levels of 20 cytokines or chemokines associated with innate and Th1/Th17 adaptive immunity were analyzed using Luminex (Millipore Corp., Billerica, MA).

Results

Overall, BB patients had increased levels of IL-8 (6.29 vs 2.12 p = 0.002) and MIP-1α/CCL3 (5.20 vs 2.06, p = 0.030), associated with innate immunity, and MIP3B/CCL19 (Th1; 297.86 vs 212.41, p = 0.031) and IL-17A (Th17; 3.11 vs 2.20, p = 0.037), associated with adaptive immunity, compared with the levels of healthy controls. When comparing acute BB vs. convalescent BB subjects vs. healthy controls, IL-1β, IL-8 and MIP-1α/CCL3 (innate mediators) levels were highest in patients in the acute phase of disease (p < 0.05). TNF-α was associated with disseminated symptoms and with humoral reactivity against Borrelia burgdorferi. IL-10 was significantly correlated with IL-6 (r = 0.59, p = 0.003), IL-8 (r = 0.51, p < 0.001), MIP-1α/CCL3 (r = 0.42, p < 0.001) and MIP-3β/CCL19 (r = 0.40, p = 0.002) in all BB patients.

Conclusions

This is the first study describing that innate and Th1/Th17 adaptive immunity play a crucial role in BB disease. Furthermore, innate mediators are particularly important in acute BB disease, and TNF-α is associated with evolution of BB symptoms.

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.

Modified interpretation criteria significantly improve performance of commercially available confirmatory assays for the serodiagnosis of Lyme borreliosis: a case-control study with clinically defined serum samples

Case-control study for the evaluation of innovative test formats for second-tier testing for the serodiagnosis of Lyme borreliosis (LB). A head-to-head comparison was performed with the test systems ViraStripe, SeraSpot, ViraChip, and recomBead. Serum samples from 62 patients (21 erythema migrans, 33 Lyme neuroborreliosis, 8 late LB) and 91 controls (including 29 potentially cross-reacting sera) were tested. For ViraChip and recomBead, optimised interpretation criteria were developed for both IgG and IgM. The most important modification for the proposed interpretation criteria for ViraChip is the interpretation of strong (> 2.5-fold above cutoff) singular IgG reactions against VlsE as positive. This significantly improves sensitivity (32 to 85%, p < 0.0001) without significant changes in specificity (borderline reactions interpreted as negative). By application of our modified rules, specificity of ViraChip IgM is significantly increased (89 to 97%, p < 0.05; borderline results included to negatives), and sensitivities of recomBead IgG and IgM are also significantly improved (69 to 87%, p < 0.01, and 57 to 74%, p < 0.01, respectively; borderline results included to positives). Further improvement of sensitivity by the rating of strong singular IgG reactions against VlsE as positive can also be shown for recomBead. IgG/IgM result combinations must be interpreted as a function of the assumed disease stage, and the best combinations differ for the various assays. Application of our proposed interpretation criteria significantly improve the discriminatory abilities of two assays; however, this must be confirmed with other data sets. Recommendations from Scientific Societies should be updated as may be necessary.

Laboratory diagnosis of Lyme borreliosis: Current state of the art and future perspectives

This review is directed at physicians and laboratory personnel in private practice and clinics who treat and diagnose Lyme borreliosis (LB) in patients as part of their daily work. A major objective of this paper is to bring together background information on Borrelia (B.) burgdorferi sensu lato (s.l.) and basic clinical knowledge of LB, which is one of the most frequently reported vector-borne diseases in the Northern Hemisphere. The goal is to provide practical guidance for clinicians and for laboratory physicians, and scientists for a better understanding of current achievements and ongoing obstacles in the laboratory diagnosis of LB, an infectious disease that still remains one of the diagnostic chameleons of modern clinical medicine. Moreover, in bringing together current scientific information from guidelines, reviews, and original papers, this review provides recommendations for selecting the appropriate tests in relation to the patient's stage of disease to achieve effective, stage-related application of current direct and indirect laboratory methods for the detection of B. burgdorferi s.l. Additionally, the review aims to discuss the current state of the art concerning the diagnostic potential and limitations of the assays and test methods currently in use to optimize LB patient management and provide insight into the possible future prospects of this rapidly changing area of laboratory medicine.

Similarities in murine infection and immune response to Borrelia bissettii and Borrelia burgdorferi sensu stricto

In 1982, Borrelia burgdorferi sensu stricto (ss) was identified as the aetiological agent of Lyme disease. Since then an increasing number of Borrelia burgdorferi sensu lato (sl) species have been isolated in the United States. To date, many of these species remain understudied despite mounting evidence associating them with human illness. Borrelia bissettii is a spirochaete closely related to B. burgdorferi that has been loosely associated with human illness. Using an experimental murine infection model, we compared the infectivity and humoral immune response with a North American isolate of B. bissettii and B. burgdorferi using culture, molecular and serological methods. The original B. bissettii cultures were unable to infect immunocompetent mice, but were confirmed to be infectious after adaptation in immunodeficient animals. B. bissettii infection resulted in spirochaete burdens similar to B. burgdorferi in skin, heart and bladder whereas significantly lower burdens were observed in the joint tissues. B. bissettii induced an antibody response similar to B. burgdorferi as measured by both immunoblotting and the C6 ELISA. Additionally, this isolate of B. bissettii was sequenced on the Ion Torrent PGM, which successfully identified many genes orthologous to mammalian virulence factors described in B. burgdorferi. Similarities seen between both infections in this well-characterized murine model contribute to our understanding of the potential pathogenic nature of B. bissettii. Infection dynamics of B. bissettii, and especially the induced humoral response, are similar to B. burgdorferi, suggesting this species may contribute to the epidemiology of human borreliosis.

Seroprevalence of Borrelia burgdorferi in occupationally exposed persons in the Belgrade area, Serbia

Lyme disease (LD) is a natural focal zoonotic disease caused by Borrelia burgdorferi, which is mainly transmitted through infected Ixodes ricinus tick bites. The presence and abundance of ticks in various habitats, the infectivity rate, as well as prolonged human exposure to ticks are factors that may affect the infection risk as well as the incidence of LD. In recent years, 20% to 25% of ticks infected with different borrelial species, as well as about 5,300 citizens with LD, have been registered in the Belgrade area. Many of the patients reported tick bites in city’s grassy areas. The aim of this study was to assess the seroprevalence of B. burgdorferi in high-risk groups (forestry workers and soldiers) in the Belgrade area, and to compare the results with healthy blood donors. A two-step algorithm consisting of ELISA and Western blot tests was used in the study. Immunoreactivity profiles were also compared between the groups. The results obtained showed the seroprevalence to be 11.76% in the group of forestry workers, 17.14% in the group of soldiers infected by tick bites and 8.57% in the population of healthy blood donors. The highest IgM reactivity was detected against the OspC protein, while IgG antibodies showed high reactivity against VlsE, p19, p41, OspC, OspA and p17. Further investigations in this field are necessary in humans and animals in order to improve protective and preventive measures against LD.

Performance of United States serologic assays in the diagnosis of Lyme borreliosis acquired in Europe

BACKGROUND

Physicians in the United States sometimes need to evaluate a patient for suspected Lyme borreliosis (LB) who may have acquired the infection in Europe. Using serum samples from European LB patients, we compared the performance of European and US serodiagnostic tests, including newer-generation assays containing Vmp-like sequence, expressed or its C6 peptide.

METHODS

The sensitivity of each assay was determined using 64 serum samples from LB patients with early or late disease manifestations who acquired the infection in Europe. Specificity was measured using 100 sera from healthy subjects from a nonendemic area.

RESULTS

For the detection of European-acquired infection, conventional 2-tiered testing (enzyme-linked immunosorbent assay [ELISA] followed by immunoblotting) using US assays had an overall sensitivity and specificity of 52% and 100%, compared with 81% (P = .0007) and 99% (P = 1.00) using analogous European tests. The sensitivity of a US C6 ELISA used as a stand-alone test (88% overall) was statistically comparable to that of conventional 2-tiered testing using European tests (P = .47) and was 100% specific. Similarly, an alternative 2-tiered algorithm using a standard US ELISA followed by a C6 ELISA was comparably sensitive (84% overall) compared with conventional 2-tiered testing using European assays (P = .82), and specificity remained 100%.

CONCLUSIONS

European assays outperformed analogous US assays in a conventional 2-tiered testing algorithm. However, a C6 ELISA used as a stand-alone test or in the second tier of a 2-tiered algorithm performed comparably to conventional 2-tiered testing using European assays, and can be used for evaluation of any patient, regardless of travel history.

Lyme optic neuritis

Lyme optic neuritis (ON) is a rare disease and only a few cases have been reported. We describe two cases of isolated Lyme ON, one with recurrence 9 months after the appearance of initial symptoms. Diagnosis criteria for multiple sclerosis and neuromyelitis optica were not met. The etiological diagnosis was based on European case definition criteria for neuroborreliosis. Both patients had positive serum and cerebrospinal fluid serology, a positive intrathecal anti-Borrelia antibody index, and a good outcome on ceftriaxone. Specific diagnosis of Lyme ON is important since improvement of visual acuity is possible with specific antibiotherapy, even after many months.

Acylated cholesteryl galactosides are specific antigens of borrelia causing lyme disease and frequently induce antibodies in late stages of disease

Borrelia burgdorferi sensu lato is the causative agent of Lyme disease (LD), an infectious disease occurring in North America, Europe, and Asia in different clinical stages. B. burgdorferi sensu lato encompasses at least 12 species, with B. burgdorferi sensu stricto, B. garinii, and B. afzelii being of highest clinical importance. Immunologic testing for LD as well as recent vaccination strategies exclusively refer to proteinaceous antigens. However, B. burgdorferi sensu stricto exhibits glycolipid antigens, including 6-O-acylated cholesteryl beta-D-galactopyranoside (ACGal), and first the data indicated that this compound may act as an immunogen. Here we investigated whether B. garinii and B. afzelii also possess this antigen, and whether antibodies directed against these compounds are abundant among patients suffering from different stages of LD. Gas-liquid chromatography/mass spectroscopy and NMR spectroscopy showed that both B. garinii and B. afzelii exhibit ACGal in high quantities. In contrast, B. hermsii causing relapsing fever features 6-O-acylated cholesteryl beta-D-glucopyranoside (ACGlc). Sera derived from patients diagnosed for LD contained antibodies against ACGal, with 80% of patients suffering from late stage disease exhibiting this feature. Antibodies reacted with ACGal from all three B. burgdorferi species tested, but not with ACGlc from B. hermsii. These data show that ACGal is present in all clinically important B. burgdorferi species, and that specific antibodies against this compound are frequently found during LD. ACGal may thus be an interesting tool for improving diagnostics as well as for novel vaccination strategies.

Evaluation of recombinant line immunoblot for detection of Lyme disease in Slovakia: comparison with two other immunoassays

In the present study the sensitivity and the specificity of three serological tests (enzyme-linked immunosorbent assay [ELISA], indirect fluorescent antibody test [IFA], and recombinant line immunoblot) were compared by examining 74 sera from patients diagnosed with Lyme disease in Eastern Slovakia. In addition, the reactivity to each of the recombinant proteins in the immunoblot was examined in order to evaluate their diagnostic value. Generally, the immunoblot (93.2%) and the ELISA (90.5%) were significantly more sensitive than the IFA (64.9%; df = 1; p < or = 0.001). Correlation between results of the ELISA, IFA, and immunoblot for IgM or IgG, when two tests were always compared, one to the other, ranged from r(s) = 0.673 to r(s) = 0.905. In the immunoblot, the highest sensitivity was observed in DbpA and VlsE proteins (76.9% and 84.6%, respectively) in IgG testing of the sera from the patient group of Lyme arthritis. VlsE proteins, together with OspC proteins, were also shown to be useful for IgM antibody detection in erythema migrans patients (up to 44.4% and 53.7% sensitivity, respectively). Our results indicate that both the ELISA and the recombinant immunoblot test were more satisfactory for seroconfirmation of Lyme disease than IFA. Moreover, the reseach confirmed diagnostic value of the in-vivo expressed proteins (VlsE and DbpA), which might have the potential to play an important role in improving whole-cell antigen-based testing.

Comparison of different Borrelia burgdorferi sensu lato strains for detection of immune response in patients with erythema migrans

The aim of the present study was to establish which combination of serological method and Borrelia strain used as an antigen would provide the most appropriate demonstration of borrelial infection in patients with eythema migrans residing in Slovenia. Four different strains were chosen as antigens: two strains of B. afzelii and two strains of B. garinii which differed in their expression of the outer proteins OspA, OspB and OspC. Each individual strain was used as antigen in immunofluorescence test (IFT), enzyme-linked immunosorbent assay (EIA) with whole borrelial cells, and EIA with ultrasonicated borrelial cells. With these 12 different tests, 100 samples were examined for the presence of specific IgM and IgG antibodies: 50 sera of blood donors and 50 sera of patients with erythema migrans. The latter were further subdivided into skin culture-positive and -negative subgroups. A commercial Western blot (WB) test was performed for 26 sera of the control group and 25 sera of patients with erythema migrans. The four different methods had distinct specificity and sensitivity. The most specific approaches were IFT (100% for IgM and 90-92% for IgG) and the WB test (100% for IgM and 73% for IgG), followed by EIA with whole borrelial cells (80-98% for IgM and 76-84% for IgG) and EIA with ultrasonicated borrelial cells (76-94% for IgM and 72-80% for IgG). The sensitivity levels of all these tests were low. The most sensitive were EIA tests with whole borrelial cells (28-36% for IgM and 32-42% for IgG) followed by EIA with ultrasonicated borrelial cells (22-32% for IgM and 24-36% for IgG), the WB test (16% for IgM and 32% for IgG) and IFT (0-2% for IgM and 14-20% for IgG). The following methods gave significant differences between patients and negative controls in detecting IgM antibodies: EIA with whole borrelial cells with both B. afzelii antigens and with antigen B. garinii that expressed OspA and OspC, EIA with ultrasonicated borrelial cells with antigen B. afzelii that expressed OspA, OspB and OspC. In detecting IgG antibodies, significant differences were observed between EIA with whole borrelial cells and with antigen B. afzelii that expressed OspA and OspB. Borreliae were isolated from the skin of 34/50 (68%) patients with erythema migrans: two strains failed to grow, while 26/32 (81%) strains were identified as B. afzelii, 5/32 (16%) as B. garinii and 1/32 (3%) as B. burgdorferi sensu stricto. No statistically significant differences in serologic test results between culture-positive and -negative patients with erythema migrans were found.

Population-based study of diagnostic assays for Borrelia infection: comparison of purified flagella antigen assay (Ideia, Dako Cytomation) and recombinant antigen assay (Liaison, DiaSorin)

Background

Testing for Borrelia-specific IgM and IgG-antibodies are often performed on a variety of poorly defined symptoms, and isolated IgM results are a frequent finding, which results in diagnostic uncertainty and further testing. We wanted to test the hypothesis that Borrelia-specific assays using recombinant antigens perform differently from assays based on purified flagella antigen.

Methods

We compared the use of recombinant antigens (LIAISON^® DiaSorin, Saluggia, Italy) and purified flagella antigen (IDEIA™ Borrelia, DakoCytomation, Glostrup, Denmark) in the assay for Borrelia-specific IgM and IgG-antibodies. The assays were tested on an unselected population of serum samples submitted from general practice. A total of 357 consecutive samples for analysis of Borrelia IgM and IgG antibodies. Furthermore, we analysed 540 samples for Borrelia-specific IgM or IgG antibodies first by the IDEIA™ and, if they were positive, the samples were further analysed using the LIAISON^® assay. To verify the correctness of the patient's serological status, discrepant samples were analysed by line blots (EcoLine, Virotech).

Results

In the consecutive series of 357 samples, the IgM assays detected 308 negative and 3 positive samples with concordant results. Compared with the line blot, the IDEIA™ system produced 21 false-positive IgM results, whereas the LIAISON^® system produced only one false-positive IgM result. The IgG assays showed 1 positive and 328 negative concordant results. The LIAISON^® system produced 9 true IgG-positive samples that were not detected by the IDEIA™ system, but the former produced 4 positive IgG results that were negative by line blot.

Conclusion

Diagnostic assays based on flagella antigen seem to show more false-positive IgM and false-negative IgG results than assays based on recombinant antigens. The latter may reduce the number of presumably false-positive IgM results and identify more IgG-positive subjects, but this system also produces more false-positive IgG results.

Borrelia burgdorferi VlsE antigen for the serological diagnosis of Lyme borreliosis

In this study, raising and development of antibody response to Borrelia burgdorferi infection in 66 Italian patients suffering from culture-confirmed Lyme borreliosis erythema migrans (EM) was investigated. Sixty-two of 66 cultures obtained from biopsies were identified as B. afzelii by PCR. A total of 175 serially collected serum samples were tested by using two different sets of commercial assays: Enzygnost Lyme link VlsE/IgG and Enzygnost Borreliosis IgM (DADE Behring, Marburg, Germany) and LIAISON Borrelia IgG and IgM (Diasorin, Saluggia, Italy). Considering only samples obtained at first presentation when EM was clinically evident, 49/66 patients (72.4%) were IgG or IgM positive by Enzygnost, whereas 33/66 (50.0%) patients were IgG or IgM positive by LIAISON. Taking into account the follow-up period, eight patients sero-converted for IgG or IgM by Enzygnost and four by LIAISON. Similar and very good specificity values were obtained by all methods. Testing sera obtained from blood donors (n = 300) and from patients suffering from some of the most common biological conditions possibly resulting in false-positive reactivity in Lyme disease serology (n = 100) showed that Enzygnost Lyme link VlsE/IgG was the more specific (98.3%), followed by LIAISON Borrelia IgG (96.5%), and considering IgM tests, Enzygnost Borreliosis IgM showed to be 95.3%% specific, whereas the LIAISON Borrelia IgM was 92.8% specific. Recombinant VlsE antigens obtained from all three B.burgdorferi genospecies pathogenic to humans (included in Enzygnost Lyme link VlsE/IgG) greatly improved serodiagnosis of Lyme disease.

Antigen biochips verify and extend the scope of antibody detection in Lyme borreliosis

The antibody response of serum IgM and IgG of patients with neuroborreliosis and erythema migrans of Lyme borreliosis (LB) was examined against a 41-kDa flagellar antigen and an 8-mer synthetic OspC8 peptide (VAESPKKP) derived from the C-terminus of outer surface protein C (OspC) from Borrelia garinii. We developed a streptavidin-modified biochip-based immunodiagnosis and compared it with conventional methods such as enzyme-linked immunosorbent assay (ELISA) and Western blot (WB). The diagnostic sensitivity of the coated biochips was demonstrated to be identical, and the results of conventional assays such as ELISA and WB were confirmed. Flagellar antigens lead to better diagnosis because of a higher discriminative value. By contrast, OspC8, a peptide derived from the outer surface antigen, is less sensitive to identify immunity in LB. The inferior antigenicity of OspC8 may be due to epitope masking. Overall, this system is open to simultaneously analyze a larger family of peptides differing in length. Thus, an array approach is generally more advantageous to extend the pattern of antigens to be tested for antigenicity in LB. Serial analysis during ongoing disease may be valuable to learn more about the course of the disease and intermittent reactivation of infection. Protein biochip as a potential substitution of ELISA and WB method offers the opportunity to study serum immunity in a multiplicity of patients simultaneously.

The use of local isolates in Western blots improves serological diagnosis of Lyme disease in Scotland

Nine Scottish Borrelia burgdorferi isolates were investigated in IgG Western blot tests. Sera previously found to be positive and negative when tested by routine Western blots prepared from reference strain B. burgdorferi sensu stricto antigen had different outcomes with these isolates. Two isolates, E5 (Borrelia afzelii) and G4 (B. burgdorferi sensu stricto) performed well, reproducing Western blot-positive results in 90 and 95 % of tests, respectively. When antigens from both isolates were incorporated into a single IgG Western blot, the results of a panel of sera were improved when compared to the routine reference strain IgG Western blot. All of the sera positive by the routine Western blot remained positive using the Scottish isolate antigen mix. Twenty-three of the 25 negative sera remained negative and two produced an equivocal result. Of the 15 samples that tested IgG Western blot equivocal with the B. burgdorferi sensu stricto reference strain, 11 (73 %) became weak or strong positive when tested with the B. afzelii/B. burgdorferi sensu stricto antigen mix (χ 2=14.35, Yates' correction, P<0.001). In seven of these, a clinical picture of Lyme disease was consistent with the new results. The use of Scottish strains of B. afzelii and B. burgdorferi sensu stricto to provide antigen for the IgG Western blot improves the diagnosis of Lyme disease for patients in Scotland.

A decrease in the immunoglobulin G antibody response against the VlsE protein of Borrelia burgdorferi sensu lato correlates with the resolution of clinical signs in antibiotic-treated patients with early Lyme disease

The purpose of this study was to evaluate the diagnostic performance of the LIAISON Borrelia Screen (Diasorin, Saluggia, Italy), a new automated immunoassay based on the chemiluminescent technology (chemiluminescence immunoassay). To assess whether a decrease in a negative value in the anti-VlsE immunoglobulin G (IgG) antibody titer was correlated with a positive response to treatment, a group of serially collected serum samples from 67 patients with culture-confirmed erythema migrans was retrospectively studied. All the patients had been treated with antibiotics and were free of disease within 3 to 6 months of follow-up. All the 15 patients who were found to be IgG positive at the time of enrollment and who were bled at least four times during the follow-up became IgG seronegative at 2 to 6 months posttreatment. These results indicate that a decline in the anti-VlsE antibody titer coincides with effective antimicrobial therapy in patients with early localized Lyme disease.

Diagnosis of lyme borreliosis

A large amount of knowledge has been acquired since the original descriptions of Lyme borreliosis (LB) and of its causative agent, Borrelia burgdorferi sensu stricto. The complexity of the organism and the variations in the clinical manifestations of LB caused by the different B. burgdorferi sensu lato species were not then anticipated. Considerable improvement has been achieved in detection of B. burgdorferi sensu lato by culture, particularly of blood specimens during early stages of disease. Culturing plasma and increasing the volume of material cultured have accomplished this. Further improvements might be obtained if molecular methods are used for detection of growth in culture and if culture methods are automated. Unfortunately, culture is insensitive in extracutaneous manifestations of LB. PCR and culture have high sensitivity on skin samples of patients with EM whose diagnosis is based mostly on clinical recognition of the lesion. PCR on material obtained from extracutaneous sites is in general of low sensitivity, with the exception of synovial fluid. PCR on synovial fluid has shown a sensitivity of up to >90% (when using four different primer sets) in patients with untreated or partially treated Lyme arthritis, making it a helpful confirmatory test in these patients. Currently, the best use of PCR is for confirmation of the clinical diagnosis of suspected Lyme arthritis in patients who are IgG immunoblot positive. PCR should not be used as the sole laboratory modality to support a clinical diagnosis of extracutaneous LB. PCR positivity in seronegative patients suspected of having late manifestations of LB most likely represents a false-positive result. Because of difficulties in direct methods of detection, laboratory tests currently in use are mainly those detecting antibodies to B. burgdorferi sensu lato. Tests used to detect antibodies to B. burgdorferi sensu lato have evolved from the initial formats as more knowledge on the immunodominant antigens has been collected. The recommendation for two-tier testing was an attempt to standardize testing and improve specificity in the United States. First-tier assays using whole-cell sonicates of B. burgdorferi sensu lato need to be standardized in terms of antigen composition and detection threshold of specific immunoglobulin classes. The search for improved serologic tests has stimulated the development of recombinant protein antigens and the synthesis of specific peptides from immunodominant antigens. The use of these materials alone or in combination as the source of antigen in a single-tier immunoassay may someday replace the currently recommended two-tier testing strategy. Evaluation of these assays is currently being done, and there is evidence that certain of these antigens may be broadly cross-reactive with the B. burgdorferi sensu lato species causing LB in Europe.

Comparative evaluation of three different ELISA methods for the diagnosis of early culture-confirmed Lyme disease in Italy

In this study the raising and development of the immune response to Borrelia burgdorferi infection in 45 Italian patients suffering from culture-confirmed Lyme borreliosis erythema migrans was investigated. A total of 95 serially collected serum samples were tested by using three different commercial ELISAs: recomWell Borrelia (Mikrogen), Enzygnost Borreliosis (DADE Behring) and Quick ELISA C6 Borrelia (Immunetics). The sensitivities of the ELISAs were as follows: Enzygnost Borreliosis IgM, 70.5 %; Quick ELISA C6 Borrelia, 62.1 %; recomWell Borrelia IgM, 55.7 %; recomWell Borrelia IgG, 57.9 %; and Enzygnost Borreliosis IgG, 36.8 %. In order to compare the specificity values of the three ELISAs, a panel of sera obtained from blood donors (210 samples coming from a non-endemic area and 24 samples from an endemic area) was tested, as well as sera from patients suffering from some of the most common biological conditions that could result in false-positive reactivity in Lyme disease serology (n = 40). RecomWell Borrelia IgG and recomWell Borrelia IgM were the most specific (97.1 % and 98.9 %, respectively), followed by Quick ELISA C6 Borrelia (96.7 %). Enzygnost Borreliosis IgG and IgM achieved 90.1 % and 92.3 % specificity, respectively. Sera that gave discrepant results when tested by the three ELISAs were further analysed by Western blotting.

Lyme borreliosis in Europe and North America

Since the discovery of the Lyme disease spirochete in North America in 1982 and in Europe in 1983, a plethora of studies on this unique group of spirochetes that compriseBorrelia burgdorferisensu lato has been accumulated. In an attempt to compare and contrast Lyme borreliosis in Europe and North America we have reviewed the biology of the aetiologic agents, as well as the clinical aspects, diagnosis and treatment of this disease on both continents. Moreover, we have detailed the ecology of theIxodesticks that transmit this infection and the reservoir hosts that maintain the spirochete cycle in nature. Finally, we have examined the transmission dynamics of the spirochete on both continents, as well as the available prevention strategies. Although it has been over two decades since the discovery of the Lyme disease spirochete, Lyme borreliosis is an expanding public health problem that has defied our attempts to control it. By comparing the accumulated experience of investigators in North America and Europe, where the disease is most frequently reported, we hope to advance the cause of developing novel approaches to combat Lyme borreliosis.

Protein A/G dependent ELISA a promising diagnostic tool in Lyme disease seroprevalence in game animals and hunting dogs

One of the major problems in serodiagnosis in wild animals is unavailability of specific antiglobulin conjugate. Our study focuses on validation of Protein A/G dependent ELISA in game animals like deer and mouflons as well as in hunting dogs. Binding ability of Protein A/G-conjugate to antibodies was the highest in dogs followed by fallow deer and mouflons. Three different whole cell Borrelia antigens were used to evaluate antigen dependent variation. In new Protein A/G-ELISA the highest sensitivities (90.50%, deer; 85.37%, mouflon & 94.29%, dog) were obtained by B. garinii antigen, with no statistically significant variation (chi(2), P>0.05) among all other antigens used. Average seroprevalences observed in deer, mouflons and dogs were 44.90%, 29.41% and 30.43%, respectively. Marked influence of age on seroprevalence was noticed. Protein A/G-ELISA proved to be sensitive and promising diagnostic tool in serodiagnosis of Lyme disease in game ungulates and it can be used effectively for serosurvey in different wild mammals.

Diversity of Ixodes-borne Borrelia species--clinical, pathogenetic, and diagnostic implications and impact on vaccine development

Among Borrelia spirochetes carried by hard ticks belonging to the various Ixodes species, at least 10 species can be distinguished. Of these, Borrelia burgdorferi sensu stricto is involved in human Lyme borreliosis in North America and Europe, and Borrelia garinii and Borrelia afzelii in human disease in Europe and Asia. The pathogenetic significance of the other species is uncertain. Although some of the Borrelia species are restricted to certain tick species, Ixodes ricinus, the vector of Lyme borreliosis in Europe, can be infested by at least five different species, including all three pathogenic species. There is evidence that different Borrelia species are preferentially found in different hosts: In Europe, B. afzelii is frequently found in small mammals, whereas B. garinii and Borrelia valaisiana are often found in birds. This could very well be related to differential sensitivity of these species to complement-mediated bactericidal activity of different hosts. Borrelial complement regulator acquiring proteins, among them OspE or Erp proteins, bind to host factor H and related proteins, and this binding protects against activation of complement by the spirochetal surface. The binding is different for proteins originating from different species and is also depending on the host origin of factor H. In Europe, B. garinii is mainly found in neuroborreliosis, whereas in skin disease B. afzelii is more frequently found. The reason is unclear. The majority of human sera cross-react between proteins of different Borrelia species, but some sera react only with proteins from one of the species. This holds especially for reactivity with OspC. A vaccine against B. burgdorferi sensu stricto has been licensed, but was recently redrawn from the market because of commercial reasons. A vaccine protecting against all three pathogenic species is not yet available.

Differential immune response to the variable surface loop antigen of P66 of Borrelia burgdorferi sensu lato species in geographically diverse populations of lyme borreliosis patients

We have studied the immune response to a variable surface-exposed loop region of the P66 outer membrane protein from Borrelia burgdorferi sensu lato by using an enzyme immunoassay. Lyme borreliosis populations found in North America and Sweden were preferentially more seroreactive to P66 from their respective regional species, namely, B. burgdorferi sensu stricto and B. garinii and B. afzelii, respectively.

DNA microarray assessment of putative Borrelia burgdorferi lipoprotein genes

A DNA microarray containing fragments of 137 Borrelia burgdorferi B31 putative lipoprotein genes was used to examine Lyme disease spirochetes. DNA from B. burgdorferi sensu stricto B31, 297, and N40; Borrelia garinii IP90; and Borrelia afzelii P/Gau was fluorescently labeled and hybridized to the microarray, demonstrating the degree to which the individual putative lipoprotein genes were conserved among the genospecies. These data show that a DNA microarray can globally examine the genes encoding B. burgdorferi lipoproteins.

Occupational risk of Lyme disease: an epidemiological review

Lyme disease is the most common vector borne disease in the United States. Since the early 1980s, a large body of literature has evaluated the occupational risk of Lyme disease. The availability of a new vaccine to prevent Lyme disease makes it necessary for occupational health professionals to make decisions regarding the occupational risk of the disease among employees.

Species-specific serodiagnosis of Lyme arthritis and neuroborreliosis due to Borrelia burgdorferi sensu stricto, B. afzelii, and B. garinii by using decorin binding protein A

The antigenic potential of decorin binding protein A (DbpA) was evaluated in serodiagnosis of human Lyme borreliosis (LB). The dbpA was cloned and sequenced from the three pathogenic Borrelia species common in Europe. Sequence analysis revealed high interspecies heterogeneity. The identity of the predicted amino acid sequences was 43 to 62% among Borrelia burgdorferi sensu stricto, B. afzelii, and B. garinii. The respective recombinant DbpAs (rDbpAs) were produced and tested as antigens by Western blotting and enzyme-linked immunosorbent assay (ELISA). One hundred percent of patients with neuroborreliosis (NB) and 93% of patients with Lyme arthritis (LA) reacted positively. Sera from the majority of patients reacted with one rDbpA only and had no or low cross-reactivity to other two variant proteins. In patients with culture-positive erythema migrans (EM), the sensitivity of rDbpA immunoglobulin G (IgG) or IgM ELISA was low. The DbpA seems to be a sensitive and specific antigen for the serodiagnosis of LA or NB, but not of EM, provided that variants from all three pathogenic borrelial species are included in the combined set of antigens.

An unusual case of anti-Borrelia burgdorferi immunoglobulin G seroconversion caused by administration of intravenous gammaglobulins

Administration of gammaglobulins to individuals without specific anti-Borrelia burgdorferi antibodies may lead to immunoglobulin G (IgG) conversion as detected by enzyme-linked immunosorbent assay (ELISA). In some cases however, complementary techniques such as Western blot or avidity will be of prime importance in distinguishing the start of an infection from the passive immunization induced by the gammaglobulins. In all cases, the key element before reaching conclusions in relation to any of these investigations remains the confrontation between the clinical context and the biological findings. This is the scenario that has been followed in our observation.

Characterization of Lyme borreliosis isolates from patients with erythema migrans and neuroborreliosis in southern Sweden

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 predominantly 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 predominantly in patients with Lyme arthritis, molecular detection of Borrelia-specific DNA in synovial samples from Lyme arthritis patients should be performed.

Genetic diversity of Pneumocystis carinii in HIV-positive and -negative patients as revealed by PCR-SSCP typing

OBJECTIVE

To describe the epidemiology of severe Pneumocystis carinii pneumonia (PCP) in HIV-infected and non HIV-infected patients.

METHODS

Bronchoalveolar lavage specimens from 212 European patients with PCP were typed using PCR--single strand conformation polymorphism analysis of four genomic regions of P. carinii f. sp. hominis. Demographic and clinical information was obtained from all patients.

RESULTS

Twenty-three per cent of the patients were presumably infected with a single P. c. hominis type. The other patients presented with two (50%) or more (27%) types. Thirty-five genetically stable and ubiquitous P. c. hominis types were found. Their frequency ranged from 0.4% to 10% of all isolates, and up to 15% of those from a given hospital. There was no significant association between the P. c. hominis type or number of co-infecting types per patient and geographical location, year of collection, sex, age, or HIV status. No more than three patients infected with the same type were observed in the same hospital within the same 6 month period, and no epidemiological link between the cases was found.

CONCLUSIONS

The broad diversity of types observed seems to indicate that multiple sources of the pathogen co-exist. There was no evidence that in our study population inter-human transmission played a significant role in the epidemiology of P. carinii.

Identifying diagnostic peptides for lyme disease through epitope discovery

Serum antibodies from patients with Lyme disease (LD) were used to affinity select peptide epitopes from 12 large random peptide libraries in phage display format. The selected peptides were surveyed for reactivity with a panel of positive sera (from LD patients) and negative sera (from subjects without LD), thus identifying 17 peptides with a diagnostically useful binding pattern: reactivity with at least three positive sera and no reactivity with any of the negative sera. The peptides define eight sequence motifs, none of which can be matched convincingly with segments of proteins from Borrelia burgdorferi, the LD pathogen; evidently, then, they are "mimotopes," mimicking natural pathogen epitopes without matching contiguous amino acids of pathogen proteins. Peptides like these could be the basis of a new diagnostic enzyme-linked immunosorbent assay for LD, with sufficient specificity and sensitivity to replace expensive immunoblotting tests that are currently required for definitive serological diagnosis. Moreover, the method used to discover these peptides did not require any knowledge of the pathogen and involved generic procedures that are applicable to almost any infectious disease, including emerging diseases for which no pathogen has yet been identified.

Molecular typing of Borrelia burgdorferi sensu lato: taxonomic, epidemiological, and clinical implications

Borrelia burgdorferi sensu lato, the spirochete that causes human Lyme borreliosis (LB), is a genetically and phenotypically divergent species. In the past several years, various molecular approaches have been developed and used to determine the phenotypic and genetic heterogeneity within the LB-related spirochetes and their potential association with distinct clinical syndromes. These methods include serotyping, multilocus enzyme electrophoresis, DNA-DNA reassociation analysis, rRNA gene restriction analysis (ribotyping), pulsed-field gel electrophoresis, plasmid fingerprinting, randomly amplified polymorphic DNA fingerprinting analysis, species-specific PCR and PCR-based restriction fragment length polymorphism (RFLP) analysis, and sequence analysis of 16S rRNA and other conserved genes. On the basis of DNA-DNA reassociation analysis, 10 different Borrelia species have been described within the B. burgdorferi sensu lato complex: B. burgdorferi sensu stricto, Borrelia garinii, Borrelia afzelii, Borrelia japonica, Borrelia andersonii, Borrelia valaisiana, Borrelia lusitaniae, Borrelia tanukii, Borrelia turdi, and Borrelia bissettii sp. nov. To date, only B. burgdorferi sensu stricto, B. garinii, and B. afzelii are well known to be responsible for causing human disease. Different Borrelia species have been associated with distinct clinical manifestations of LB. In addition, Borrelia species are differentially distributed worldwide and may be maintained through different transmission cycles in nature. In this paper, the molecular methods used for typing of B. burgdorferi sensu lato are reviewed. The current taxonomic status of B. burgdorferi sensu lato and its epidemiological and clinical implications, especiallly correlation between the variable clinical presentations and the infecting Borrelia species, are discussed in detail.

Validity of interpretation criteria for standardized Western blots (immunoblots) for serodiagnosis of Lyme borreliosis based on sera collected throughout Europe

Western blotting (WB; immunoblotting) is a widely used tool for the serodiagnosis of Lyme borreliosis (LB), but so far, no generally accepted criteria for performance and interpretation have been established in Europe. The current study was preceeded by a detailed analysis of WB with whole-cell lysates of three species of Borrelia burgdorferi sensu lato (U. Hauser, G. Lehnert, R. Lobentanzer, and B. Wilske, J. Clin. Microbiol. 35:1433-1444, 1997). In that study, interpretation criteria for a positive WB result were developed with the data for 330 serum samples (from patients with LB in different stages [n = 189] and from a control group [n = 141]) originating mostly from southern Germany. In the present work, the interpretation criteria for strains PKo (Borrelia afzelii) and PBi (Borrelia garinii) developed in the previous study were reevaluated with 224 serum samples (from patients with LB in different stages [n = 97] and from a control group [n = 127]) originating from throughout Europe that were provided by the European Union Concerted Action on Lyme Borreliosis (EUCALB). De novo criteria were developed on the basis of the reactivities of the EUCALB sera and were evaluated with the data for the samples from southern Germany. Comparison of all results led to the following recommendations: For WB for immunoglobulin G (IgG), at least two bands among p83/100, p58, p43, p39, p30, OspC, p21, p17, and p14 for PKo and at least one band among p83/100, p39, p30, OspC, p21, and p17b for PBi; for WB for IgM, at least one band among p39, OspC, and p17 or a strong p41 band for PKo and at least one band among p39 and OspC or a strong p41 band for PBi. WB with PKo was the most sensitive, and this strain is recommended for use in WB for the serodiagnosis of LB throughout Europe.