Comparison of four immunoserologic assays for detection of antibodies to Borrelia burgdorferi in patients with culture-positive erythema migrans

Lyme disease: Is it or is it not?

This past summer, Lyme disease was the topic of a Focus section in the Globe and Mail (1). In this section, the reporter described her experience of having physicians unable and then unwilling to diagnose her symptoms of "skin on fire, dizziness and chest pains, twitching muscles, and trouble keeping balance" as Lyme disease following a tick bite three years previously on Prince Edward Island. She reported finding support for her diagnosis after obtaining a positive test from a California laboratory and after seeing approximately 20 physicians. In her article, she speaks to the controversy surrounding the diagnosis and treatment of Lyme disease, and the tension it creates between those who believe they have it and the physicians they see.

Impact of clinical variables on Borrelia burgdorferi-specific antibody seropositivity in acute-phase sera from patients in North America with culture-confirmed early Lyme disease

Erythema migrans, the most common manifestation of Lyme disease, has been associated with highly variable rates of seropositivity for antibodies to Borrelia burgdorferi. Differences in the sensitivities of serologic assays for the detection of these antibodies, however, may not be the only or even the primary explanation for this observation. We investigated the impacts of four clinical variables on seropositivity--the duration of erythema migrans, the presence of single versus multiple skin lesions, and the gender and age of the patient. In this analysis, three different serologic tests were performed on acute-phase sera from 175 untreated patients with culture-confirmed erythema migrans: the C6 single-peptide enzyme-linked immunosorbent assay (ELISA), a commercially available ELISA in which a whole-cell sonicate of B. burgdorferi was the antigen, and a two-tier procedure. Irrespective of the serologic test performed, the results showed that seropositivity rates increased with the duration of the erythema migrans for patients with single lesions (P < 0.001) but not for those with multiple skin lesions. The variability in seropositivity rates was greatest for the two-tier testing strategy, with a >6-fold-higher rate of seropositivity among patients with a single lesion of 22- to 30-day duration than among those whose skin lesion was of 1- to 7-day duration (85.7 versus 14.1%; P < 0.001). Rates of seropositivity by each of the testing methods were also significantly higher for patients with multiple skin lesions than for those with single lesions (P < 0.001). In contrast, seropositivity rates were not affected by either the gender or the age of the patient. Thus, in patients with erythema migrans, certain clinical variables such as the duration and number of skin lesions had a profound impact on seropositivity rates, irrespective of the serologic assay performed.

Lyme disease: laboratory issues

This article describes the laboratory modalities available to confirm the diagnosis of Lyme borreliosis. Use and limitations of these methods are discussed. Current guidelines for the use of recommended serologic methods and discussion of newer methods also are provided.

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.

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.

Improved serodiagnosis of early Lyme borreliosis: immunoblot with local Borrelia afzelii strain

To improve the serodiagnosis of Lyme borreliosis (LB) the performances of four tests were evaluated. An indirect immunofluorescent assay based on Borrelia burgdorferi s.s., enzyme-linked immunosorbent assay (ELISA) based on local isolates of Borrelia afzelii and B. burgdorferi s.s., and immunoblot (IB) of B. afzelii were prepared. The serum panels contained 214 serum samples: control group (n=120) and patients at different stages of LB (n=94). The specificity of IB was 96%, of in-house ELISA 93%, and of IFA 89%. In early LB the sensitivity of IFA was 36%, ELISA 67%, and IB 93%. In late-stage LB the sensitivity was: 72% for IFA, 80% for ELISA, and 94% for IB. Comparison of in-house and Behring ELISA showed that the sensitivity of the serological assay could be increased when the test was based on local Borrelia strains. IgM and IgG antibodies from sera of patients with early and late LB most frequently demonstrated reactivity to OspC. The other significant proteins in early LB were: p39, p41 in IgM IB, and p83/100, p39, Osp17 in IgG IB; in late LB: p39, p41 in IgM IB, and p83/100, Osp17, p21 and p43 in IgG IB. Using IB based on local B. afzelii isolates improves the serodiagnosis of early LB in our geographical region.

New rapid enzyme-linked immunosorbent assay to detect antibodies against bacterial surface antigens using filtration plates

An easy and rapid ELISA system, Filtration ELISA, to detect antibodies against bacterial cell surface antigens was developed using a 96-well filtration plate fitted with a 0.22microm membrane (MultiScreen-GV, Millipore). Bacterial whole cells were used as antigens without fixing the cells with formalin etc. The whole cell antigens were washed by vacuum filtration through a filter and resuspended in washing buffer. Assay reactions could be done in the wells without losing the solution. The technique was established using antisera of mice immunized with Escherichia coli, and then evaluated by assaying antibodies to Shiga-toxin producing E. coli O157:H7 (STEC), Staphylococcus aureus and Lactobacillus acidophilus in fecal extracts of 157 children who had eaten school lunches contaminated with STEC in comparison with 25 age-matched control children. The lunch group showed significantly higher IgA antibody titers against STEC than the control group (p<0.0005), but not against L. acidphilus. The results indicate that Filtration ELISA is a quantitative and specific technique for measuring antibodies against antigens on the surface of bacteria without extracting antigens from the bacteria. This technique is widely applicable to the assay of antibodies in various samples including serum and fecal extract against various kinds of bacteria.

Recombinant BBK32 protein in serodiagnosis of early and late Lyme borreliosis

Borrelial protein BBK32 was evaluated as an antigen in the serodiagnosis of early and disseminated Lyme borreliosis (LB). bbk32 was cloned and sequenced from eight isolates of the three pathogenic Borrelia species. The identities between the amino acid sequences of the BBK32 proteins from Borrelia burgdorferi sensu stricto, B. garinii, and B. afzelii isolates were 71 to 100%. By immunoglobulin G (IgG) Western blotting (WB) or enzyme-linked immunosorbent assay (ELISA), up to 74 and 100% of acute- and convalescent-phase samples, respectively, from 23 patients with erythema migrans (EM) were positive for recombinant BBK32 protein from B. afzelii. In the serology of disseminated LB, the three variant BBK32 antigens cross-reacted. In total, 14 of 14 samples from patients with neuroborreliosis and 15 of 15 samples from patients with Lyme arthritis were positive. The specificities of the IgG ELISA with the variant BBK32 antigens for EM and disseminated borreliosis were 81 to 92% and 89 to 95%, respectively. Our findings indicate that the BBK32 proteins are promising serodiagnostic antigens for the detection of early and disseminated LB but that variant BBK32 proteins may be needed either in parallel or in combination with an immunoassay for LB to cover all the relevant borrelial species that cause the disease.

Use of serum immune complexes in a new test that accurately confirms early Lyme disease and active infection with Borrelia burgdorferi

The present recommendation for serologic confirmation of Lyme disease (LD) calls for immunoblotting in support of positive or equivocal ELISA. Borrelia burgdorferi releases large quantities of proteins, suggesting that specific antibodies in serum might be trapped in immune complexes (ICs), rendering the antibodies undetectable by standard assays using unmodified serum. Production of ICs requires ongoing antigen production, so persistence of IC might be a marker of ongoing or persisting infection. We developed an immunoglobulin M (IgM) capture assay (EMIBA) measuring IC-derived IgM antibodies and tested it using three well-defined LD populations (from an academic LD referral center, a well-described Centers for Disease Control and Prevention (CDC) serum bank, and a group of erythema migrans patients from whose skin lesions B. burgdorferi was grown) and controls (non-Lyme arthritis inflammatory joint disease, syphilis, multiple sclerosis, and nondisease subjects from a region where LD is endemic, perhaps the most relevant comparison group of all). Previous studies demonstrated that specific antigen-antibody complexes in the sera of patients with LD could be precipitated by polyethylene glycol and could then be disrupted with maintenance of the immunoreactivity of the released antibodies, that specific anti-B. burgdorferi IgM was concentrated in ICs, and that occasionally IgM to specific B. burgdorferi antigens was found in the IC but not in unprocessed serum. EMIBA compared favorably with commercial and CDC flagellin-enhanced enzyme-linked immunosorbent assays and other assays in confirming the diagnosis of LD. EMIBA confirmed early B. burgdorferi infection more accurately than the comparator assays. In addition, EMIBA more accurately differentiated seropositivity in patients with active ongoing infection from seroreactivity persisting long after clinically successful antibiotic therapy; i.e., EMIBA identified seroreactivity indicating a clinical circumstance requiring antibiotic therapy. Thus, EMIBA is a promising new assay for accurate serologic confirmation of early and/or active LD.

Tickborne infections as a cause of nonspecific febrile illness in Wisconsin

Lyme disease, human granulocytic ehrlichiosis (HGE), and babesiosis are tickborne infections that are indigenous to Wisconsin. To assess their importance as a cause of nonspecific fever, we recruited patients with febrile illness at 10 clinics in northwestern Wisconsin from May through August of both 1997 and 1998. Eligible patients had a temperature >38.0 degrees C but no rash or other localizing source. Acute and convalescent serological tests were performed for Borrelia burgdorferi, Babesia microti, and Ehrlichia equi; polymerase chain reaction was performed to detect granulocytic Ehrlichia rDNA. Seventeen (27%) of 62 eligible patients had laboratory evidence of tickborne infection, including 7 (11%) with probable Lyme disease only, 8 (13%) with HGE only, and 2 (3%) with apparent coinfection. No patients with Babesia infection were identified. Patients with and without tickborne infection were similar with regard to age, sex, symptoms, history of tick bite, and outdoor exposure. The results suggest that tickborne infections are an important cause of nonspecific febrile illness during the tick season in northwestern Wisconsin.

Lyme borreliosis

Lyme borreliosis is a worldwide, multistage, and multi-system disease caused by borrelia spirochetes, which are transmitted by ixodes ticks. It is focally endemic in temperature climates of the northern hemisphere. Primary erythema migrans occurs at the site of inoculation. Secondary erythema migrans occurs at sites of hematogenous dissemination. Variations in genospecies account for variations in presentation, including borrelial lymphocytoma. Disseminated disease includes constitutional signs and symptoms, intermittent oligoarticular arthritis, meningitis, cranial neuritis, radiculoneuropathy, encephalopathy, atrioventricular block, and myopericarditis. Late persistent disease includes acrodermatitis chronica atrophicans, chronic arthritis, neurological impairment, and fatigue. There can be difficulties with both clinical and laboratory diagnosis. First-line oral therapies for early uncomplicated disease are doxycycline and amoxicillin. First-line intravenous therapy for complicated or resistant disease is ceftriaxone. Prevention includes avoiding tick habitats, dressing sensibly, judicious use of repellants, and early removal of imbedded ticks. Vaccination is indicated only for frequent or prolonged exposure to tick-infested habitat.

Borrelioses, agentes e vetores

As borrelioses são enfermidades infecciosas determinadas por espiroquetas do gênero Borrelia, agentes transmissíveis, principalmente, por carrapatos aos animais e/ou ao homem. Nesta revisão são apresentadas e discutidas as enfermidades determinadas por borrélias, bem como as características gerais das espiroquetas, os aspectos relacionados a transmissão por artrópodes, as enfermidades nos animais domésticos e silvestres, quanto aos aspectos biológicos e patológicos, a doença de Lyme como principal zoonose do grupo, a associação de borrélia com outros agentes hematozoários e os métodos diagnósticos e a epidemiologia comparativa entre dados obtidos no Brasil com os de outros países. Estas borrelioses possuem características patológicas, clínicas e epidemiológicas variadas de acordo à região fisiográfica, devido à existência de distintas espécies, genoespécies e cepas; estes aspectos variam ainda em função dos artrópodes vetores, da interação vetor-patógeno e dos ecossistemas distintos.

Clinical and epidemiological features of early Lyme disease and human granulocytic ehrlichiosis in Wisconsin

To compare clinical features and assess risk factors for human granulocytic ehrlichiosis (HGE) and early Lyme disease, we enrolled patients in a case-control study during the 1996 and 1997 tick seasons. Clinical and demographic characteristics were assessed for patients with laboratory-confirmed cases of HGE or Lyme disease, and risk factors were compared with those of matched control subjects. We identified 83 persons with Lyme disease, 27 with HGE, and 11 with apparent coinfection. Unsuspected Ehrlichia infection was identified in 8 (13%) of 60 patients with Lyme disease. Patients with HGE were older and more likely to have fever, chills, or dyspnea than were those with Lyme disease only. Most patients with apparent coinfection did not have hematologic abnormalities. In the risk factor analysis, tickborne illness was independently associated with rural residence and camping. The clinical spectrum of HGE overlaps that of Lyme disease, and physicians in areas of endemicity should consider both diseases in treating patients with a compatible rash or febrile illness.

Immunoglobulin M capture assay for serologic confirmation of early Lyme disease: analysis of immune complexes with biotinylated Borrelia burgdorferi sonicate enhanced with flagellin peptide epitope

We previously reported on the efficacy of the enzyme-linked immunoglobulin M capture immune complex (IC) biotinylated antigen assay (EMIBA) for the seroconfirmation of early Lyme disease and active infection with Borrelia burgdorferi. In earlier work we identified non-cross-reacting epitopes of a number of B. burgdorferi proteins, including flagellin. We now report on an improvement in the performance of EMIBA with the addition of a biotinylated form of a synthetic non-cross-reacting immunodominant flagellin peptide to the biotinylated B. burgdorferi B31 sonicate antigen source with the avidin-biotinylated peroxidase complex detection system used in our recently developed indirect IgM-capture immune complex-based assay (EMIBA). As in our previous studies, the enzyme-linked immunosorbent assay (ELISA) reactivities of antibodies liberated from circulating ICs (by EMIBA) were compared with those of antibodies in unprocessed serum (antibodies found free in the serum, thus as an IgM-capture ELISA, but not EMIBA, because the antibodies were not liberated from ICs), the sample usually used in standard ELISAs and Western blot assays. The addition of the flagellin epitope enhanced the ELISA signal obtained with untreated sera from many Lyme disease patients but not from healthy controls. In tests with both free antibodies and ICs, with or without the addition of the flagellin epitope to the sonicate, we found the most advantageous combination was IC as the source of antibodies and sonicate plus the flagellin epitope as the antigen. In a blinded study of sera obtained from patients with early and later-phase Lyme disease, EMIBA with the enhanced antigenic preparation compared favorably with other serologic assays, especially for the confirmation of early disease.

Heterogeneity of BmpA (P39) among European isolates of Borrelia burgdorferi sensu lato and influence of interspecies variability on serodiagnosis

The molecular and antigenic variabilities of BmpA (P39) among European isolates of Borrelia burgdorferi were analyzed. The bmpA sequences of 12 isolates representing all three species of B. burgdorferi sensu lato pathogenic for humans were amplified by PCR, cloned, and sequenced. The BmpA protein of Borrelia garinii is heterogeneous, with an amino acid sequence identity ranging from 91 to 97%, whereas the BmpA proteins of Borrelia afzelii and B. burgdorferi sensu stricto strains appear to be highly conserved (>98.5% intraspecies identity). The interspecies identities ranged from 86 to 92%. Cluster analysis of BmpA reflected the subdivision of B. burgdorferi sensu lato isolates into the three species as well as a considerable heterogeneity among B. garinii strains. The BmpA protein of each species of B. burgdorferi sensu lato was recombinantly expressed in Escherichia coli, purified, and used to generate monoclonal antibodies. Seven BmpA-specific antibodies were identified; six of them recognized conserved epitopes of all three species, whereas one was specific for BmpA of B. afzelii and B. garinii. A monoclonal antibody (H1141) recommended by the Centers for Disease Control and Prevention for use in the standardization of immunoblots showed strong reactivity with BmpA of B. burgdorferi sensu stricto but no or only weak reactivity with BmpA of B. garinii and B. afzelii, respectively. Sera from 86 European patients with Lyme borreliosis in different stages and 73 controls were tested in immunoglobulin G (IgG) and IgM immunoblots with the recombinant BmpA proteins of the three species, revealing specificities of 98.6 to 100%. IgM antibodies against recombinant BmpA were only rarely detected (1.1 to 8.1%). With the BmpA proteins of B. afzelii and B. garinii, sensitivities for the IgG test (sera from stages I to III) were 36.0 and 34.9%, respectively, in contrast to 13.9% with BmpA of B. burgdorferi sensu stricto. Therefore, we recommend that recombinant BmpA of B. afzelii or B. garinii should be used solely, or in addition to B. burgdorferi sensu stricto BmpA, in serodiagnostic tests for Lyme borreliosis in Europe.

Clinical comparison of borreliacidal-antibody test with indirect immunofluorescence and enzyme-linked immunosorbent assays for diagnosis of Lyme disease

OBJECTIVE

To compare the clinical results with the borreliacidal-antibody test (BAT) and two standard screening serologic tests for Lyme disease (LD)-the indirect immunofluorescence assay (IFA) and the enzyme-linked immunosorbent assay (ELISA).

DESIGN

The medical records of patients from an endemic LD area, who had been serologically tested during the summer of 1992, were retrospectively categorized by clinical diagnoses without results of serologic tests. Serologic testing, which included control serum samples from patients from a nonendemic LD area, was performed in a blinded fashion, and the results were compared with the clinical categories.

MATERIAL AND METHODS

Medical records of 307 patients who had been serologically tested for LD were reviewed. We found untreated, active LD in 43 patients (early-localized LD, 21; early-disseminated LD, 14; and late-disseminated LD, 8) and treated LD in 33. Non-LD cases were categorized into acute or chronic conditions of unknown or known cause.

RESULTS

Overall, the BAT had a sensitivity of 11% in active LD and did not correlate with results of other conventional surface antibody assays. The IFA and ELISA were more sensitive (67 to 93%), but false-positive results frequently were noted (20 to 40%) in acute and chronic non-LD inflammatory conditions. The specificity of the BAT, IFA, and ELISA in the control group was 96%, 93%, and 97%, respectively.

CONCLUSION

Until the sensitivity, as measured by prospective clinical studies, is improved without loss of specificity, the BAT should not be used clinically for the diagnosis of LD. Suspected cases of LD with atypical clinical manifestations should have positive ELISA and IFA results confirmed with a standardized immunoblot assay.

Immunoserologic evidence of coinfection with Borrelia burgdorferi, Babesia microti, and human granulocytic Ehrlichia species in residents of Wisconsin and Minnesota

In Wisconsin and Minnesota, Ixodes scapularis (Ixodes dammini) ticks are the vector of three microorganisms that may cause significant disease in humans and lower mammals. These diseases include Lyme borreliosis, which is caused by Borrelia burgdorferi, babesiosis, which is caused by Babesia microti, and human granulocytic ehrlichiosis (HGE), which is caused by an apparently new species in the genus Ehrlichia. Immunoserologic testing was performed on sera from patients with a diagnosis of one of these diseases to determine if there was evidence of coinfection with one or more of the other agents. Of 96 patients with Lyme borreliosis, 9 (9.4%) demonstrated immunoserologic evidence of coinfection: 5 (5.2%) with the agent of HGE, 2 (2.1%) with B. microti, and 2 (2.1%) with both microorganisms. Of 19 patients diagnosed with HGE, 3 (15.8%) showed immunoserologic evidence of coinfection: 1 (5.3%) with B. burgdorferi, 1 (5.3%) with B. microti, and 1 (5.3%) with both microorganisms. One patient diagnosed with babesiosis was also seropositive for ehrlichiosis. These results provide evidence for coinfection, perhaps explaining the variable manifestations and clinical responses noted in some patients with tick-transmitted diseases. In certain clinical settings, laboratory testing for coinfection is indicated to ensure that appropriate antimicrobial treatment is given.

Evolution of the serologic response to Borrelia burgdorferi in treated patients with culture-confirmed erythema migrans

We investigated the appearance and evolution of immunoglobulin M (IgM) and IgG antibodies to Borrelia burgdorferi in 46 patients with culture-proven erythema migrans (EM). All patients received antimicrobial treatment and were prospectively evaluated for up to 1 year. A total of 257 serially collected serum samples were tested by commercial IgG-IgM enzyme-linked immunosorbent assay and separate IgM and IgG immunoblots (IBs). At the baseline, 33% of the patients had a positive ELISA result and 43% of the patients had a positive IgM IB result by using the criteria of the Centers for Disease Control and Prevention-Association of State and Territorial Public Health Laboratory Directors for the interpretation of IB results. Positive serology at the baseline and the rate of seroconversion correlated directly with disease duration and/or evidence of dissemination prior to treatment. At days 8 to 14 after the baseline, 91% of patients had a positive ELISA result and/or IgM IB result. Peak IgM antibody levels were seen at this time in patients with localized or disseminated disease. The most frequent IgM bands at the baseline and the peak were of 24 kDa (OspC), 41 kDa, and 37 kDa. Although 89% of the patients developed IgG antibodies as determined at a follow-up examination, only 22% were positive by the IgG IB criteria of the Centers for Disease Control and Prevention-Association of State and Territorial Public Health Laboratory Directors. The persistence of antibodies was directly related to disease duration and/or dissemination prior to treatment. Since IgM antibodies to the 24- and 41-kDa antigens remained detectable for long periods, 38% of IgM IBs were still positive at 1 year postbaseline. IgM to antigens of 39, 58, 60, 66, or 93 kDa, conversely, were most often seen in sera obtained within 1 month postbaseline. Their presence may be of assistance in confirming a recent infection with B. burgdorferi in individuals living in areas where Lyme disease is endemic.

An epidemiologic study of Lyme disease in southern Sweden

BACKGROUND

Lyme disease is the most common vector-borne infection in some temperate regions of the Northern Hemisphere. However, for most areas of endemic disease reliable epidemiologic data are sparse.

METHODS

Over a one-year period, we conducted a prospective, population-based survey of cases of Lyme disease in southern Sweden. The diagnosis was made on the basis of the presence of erythema migrans at least 5 cm in diameter or characteristic clinical manifestations such as arthritis, neuroborreliosis, and carditis.

RESULTS

We identified 1471 patients with Lyme disease, for an overall annual incidence of 69 cases per 100,000 inhabitants. The incidence varied markedly according to geographic region, and there were several areas where disease was widely prevalent. The incidence varied according to age, with the highest rates among people 5 to 9 and 60 to 74 years of age, but not according to sex. The most frequent clinical manifestation was erythema migrans (seen in 77 percent of all cases), followed by neuroborreliosis (16 percent) and arthritis (7 percent). Carditis was rare. A preceding tick bite was reported by 79 percent of the patients. Bites in the head and neck region were more common among children than among adults and were associated with an increased risk of neuroborreliosis.

CONCLUSIONS

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

Antibodies against whole sonicated Borrelia burgdorferi spirochetes, 41-kilodalton flagellin, and P39 protein in patients with PCR- or culture-proven late Lyme borreliosis

The sensitivities and specificities of three enzyme-linked immunosorbent assays (ELISAs) for Borrelia burgdorferi antibodies were compared for 41 patients presenting with symptoms compatible with late Lyme borreliosis (LB) and 37 healthy controls. All subjects were living in southwestern Finland, where LB is endemic. Only patients with culture- or PCR-proven disease were enrolled in the study. The antigens of the ELISAs consisted of sonicated spirochetes, 41-kDa flagellin, and recombinant P39 protein of B. burgdorferi. Fifteen patients had strongly or moderately positive results in the serological assay(s), 19 patients had only weakly positive or borderline antibody levels, and the remaining 7 patients were seronegative by ELISA. The sensitivities of the ELISAs were 78.0% with sonicate antigen, 41.5% with 41-kDa flagellin, and 14.6% with P39 protein. The specificities of the tests were 89.2, 86.5, and 94.6%, respectively. The sonicate antigen ELISA seems to be an effective screening method. These results show that antibodies to B. burgdorferi may be present in low levels or even absent in patients with culture- or PCR-proven late LB. Therefore, in addition to serological testing, the use of PCR and cultivation is recommended in the diagnosis of LB.