The European Union Concerted Action World Wide Web site for Lyme borreliosis

Lyme neuroborreliosis: do we treat according to guidelines?

Evidence-based guidelines, published in 2010, equate the efficacy of oral and intravenous antibiotics and recommend treatment duration of 2 weeks in early Lyme neuroborreliosis (LNB) without encephalitis or myelitis. Further, the Norwegian health authorities give a general advice to choose oral rather than intravenous administration when proven effective, due to lower costs, fewer risks, and reduced patient inconvenience. In this study we aimed to chart LNB treatment practice in Norway and compare it to these recommendations. Adult patients diagnosed with definite LNB between 2007 and 2013 in 11 different hospitals in the four health regions in Norway were invited to answer a questionnaire regarding duration and administration of antibiotic treatment. A total of 253 patients answered. Median age at diagnosis was 59 years (range 19-83), and 125 (49%) were women. Duration of treatment was 1 week in 7 (3%) patients, 2 weeks in 81 (32%), 3 weeks in 62 (25%), 4 weeks in 48 (19%), 5 weeks in 12 (5%), ≥6 weeks in 29 (12%), and unknown in 14 (6%). Treatment was given orally in 77 (30%) patients, intravenously in 110 (44%), both orally and intravenously in 65 (26%), and unknown in one. Treatment practices differed between the health regions (p = 0.002). During the study period, there were no significant time trend neither with respect to proportion of patients treated for only 2 weeks (OR 0.899, p = 0.109) nor with respect to proportion of patients treated exclusively with oral antibiotics (OR 1.131, p = 0.074). In conclusion, there seem to be a gap between evidence-based recommendations and treatment practice of LNB in Norway.

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.

[Microbiological and pharmacological data useful for the treatment of Lyme disease. Treatment and follow up of early Lyme disease (erythema migrans)]

The aim of this review was first to analyze the microbiological and pharmacological criteria used to choose a treatment for Lyme disease. The determination of Borrelia burgdorferi sensu lato susceptibility to antibiotics is difficult, especially because of the lack of standardization in the methods used. In vitro data is helpful to determine Lyme treatment but discrepancies between in vitro and in vivo results highlight the need to confirm this data by clinical trials. The second part is an analysis of the literature made to evaluate the current strategies of treatment and follow up of early Lyme disease characterized by erythema migrans (EM). beta-lactams (penicillin G and V, amoxicillin, cefuroxime axetil, ceftriaxone), tetracyclines (doxycycline), and macrolides (mainly azithromycin) are the drugs most frequently used during clinical trials. The comparison between treatments is difficult because of the lack of reliable clinical and biological criteria to identify complete recovery. However the prognosis of treated EM is good in most trials. If a clinical follow-up remains necessary after the treatment of an EM, prolonged antibody production among asymptomatic patients reduces the interest of a serological follow-up.

Traitement et suivi des phases secondaire et tertiaire de la borréliose de Lyme

The aim of this review was to analyze the current strategies of treatment and follow-up of disseminated and late Lyme borreliosis. A comprehensive search was performed using the Medline database. Only relevant reviews, expert guidelines and randomized controlled clinical trials were selected and, if necessary, open trials. Major drugs used in these studies were amoxicillin, doxycycline, penicillin G, and ceftriaxone. Oral administration of antibiotics was preferred in Lyme arthritis whereas parenteral drugs were mostly used in neuroborreliosis. The treatment duration usually ranged from 14 to 30 days. Prolonged antibiotic courses recommended by some authors in post-Lyme syndromes were not validated by several randomized placebo controlled studies. Follow up patterns were analyzed in order to determine possible prognosis parameters allowing to distinguih active Borrelia burgdorferi infection from a sequel of infection.

[Retrospective study of Lyme borreliosis positive serologies in 2003]

PURPOSES OF THE STUDY

To estimate the percentage of positive sera for Lyme borreliosis antibodies, to precise the characteristics of clinical cases diagnosed from serological data and to determine their geographical distribution in France.

MATERIALS AND METHODS

Studied sera were those received by the Pasteur-Cerba laboratory in 2003. IgG and IgM isotypes were detected using the Dade Behring kits. Antibody specificity was analysed with the Meridian's western blot.

RESULTS

1504/16 176 (9%) sera were positive for IgG isotype, and 978/3298 (29%) for IgM. The specificity was confirmed by western blot in 49% cases for IgG and in 54% for IgM. The highest positive serology rates were found in eastern and centre regions and in Aquitaine. Forty-two cases have been investigated leading to the identification of 16 borreliosis cases, each suffering of an erythema migrans. Five of them had neurological signs. Patient mean age was 40 years. 87% of patients had risk factors and 69% reported previous tick bites, mainly on lower limbs.

CONCLUSION

A low rate of positive borreliosis sera was found, suggesting that serology prescription should be limited to patients suffering of compatible clinical signs, as recommended by the EUCALB. Erythema migrans was the most frequent clinical manifestation and neurological signs were present in 30% of cases. Finally, the geographical case distribution was similar to that provided by the study of the Sentinelle network in 1999-2000.

Borrelia burgdorferisensu lato infection in passerine birds from the Mazurian Lake region (Northeastern Poland)

The aim of the present study was to evaluate a potential role of different passerine birds species in Mazurian Lake region (northeast Poland) in the spread of Borrelia burgdorferi sensu lato, the spirochaete that causes Lyme disease. A total number of 1254 birds (representing 42 species) were captured during the 3-year study period. Blood samples were collected from birds and analyzed with a nested polymerase chain reaction technique in order to detect fragments of the pathogen DNA. Positive results were obtained in 4.2% of all blood samples. Specifically, B. burgdorferi s.l. were detected in tree pipit (Anthus Erivialis; 21.1% of 19 birds), dunnock (Prunella modularis; 15.8% of 19 birds), chaffinch (Fringilla coelebs; 12.7% of 166 birds), song thrush (Turdus philometos; 9.3% of 54 birds), nuthatch (Sitta euopea; 7.7% of 26 birds), hawfinch (Coccothraustes coccothroustes; 6.7% of 15 birds), robin (Erithacus rebecula; 5.1% of 256 birds), blackbird (Turdus merula; 4.2% of 71 birds) and wren (Troglodytes troglodytes; 3.7% of 27 birds). Additionally, the incidence of the infection was analyzed in relation to the habitat in which the birds resided (mixed coniferous forest or alder swamp forest), months of the study (from April to October), age and sex, but the differences were not statistically significant.

Identification of Borrelia burgdorferi sensu lato, Anaplasma and Ehrlichia species, and spotted fever group Rickettsiae in ticks from Southeastern Europe

Prevalence data for tick-borne pathogens are used to assess the risk for human health. In this study the presence and identity of Borrelia burgdorferi sensu lato, Ehrlichia, Anaplasma, and Rickettsia species in Bulgarian Ixodes ricinus ticks and in non- Ixodes ticks from Turkey and Albania was determined by polymerase chain reaction (PCR) and reverse line blot hybridization. In the adult Bulgarian ticks, the prevalence of Borrelia burgdorferi sensu lato infection was approximately 40%, while Borrelia afzelii was the predominant species, representing more than half of all Borrelia-positive ticks. Ehrlichia and Anaplasma species were detected in 35% of the adult Ixodes ricinus ticks and in 10% of the nymphs. Sequence analysis of PCR products reacting with the Anaplasma phagocytophila probe revealed a 16S rRNA gene identical to that of the Anaplasma phagocytophila prototype strain. Ehrlichia and Anaplasma species were found in approximately 7% of the non- Ixodes ticks. Sequence analysis of some of these samples revealed the presence of Anaplasma ovis, Ehrlichia canis, and a species closely resembling Ehrlichia chaffeensis. About half of all adult ticks examined and approximately 20% of all nymphs were infected with Rickettsia species. In Ixodes ricinus ticks, Rickettsia helvetica and a Rickettsia species designated as IRS3 were found in high prevalence. Rickettsia conorii was found in virtually all non- Ixodes tick species from Albania and Turkey. The results of this study show that many tick-borne diseases are most probably endemic in the Balkan area. Furthermore, the results suggest that there is a considerable chance for simultaneous transmission of tick-borne pathogens to human beings.

Laboratory testing for suspected Lyme disease

Laboratory testing for B. burgdorferi infection is intended to substantiate a physician's clinical judgment of whether a patient has Lyme disease or not. Cultivation of B. burgdorferi from a patient's skin or blood is the gold standard for demonstration of active infection, but it is expensive and lacks clinical sensitivity. Detection of spirochetal DNA in clinical samples by PCR has better sensitivity, but PCR for B. burgdorferi has not yet been standardized for more routine diagnostic testing. Detection of antibodies to B. burgdorferi is the most practical and common approach for laboratory work-up of a case of suspected Lyme disease. Serologic assays fall short of 100% sensitivity and specificity, however, and examination of a single specimen in time does not discriminate between previous and ongoing infection. Because of a background false positivity even among healthy populations of nonendemic regions, serologic testing is recommended only when there is at least a one in five chance, in the physician's estimation, that the patient has active Lyme disease. The pretest likelihood of the disease is determined by the physician in the context of epidemiologic and clinical facts of the case. This estimate can serve to reassure patients who are at low risk of B. burgdorferi infection but are seeking a Lyme test for complaints of a more nonspecific nature. Although new subunit serologic assays based on recombinant proteins are becoming available commercially, the longstanding two-test approach, in which a positive or indeterminate result with a standardized, sensitive ELISA test is followed by verification with a more specific Western blot assay, still provides the physician with a reasonably accurate and reliable assessment of the presence of antibodies to B. burgdorferi. More recent challenges for serologic testing are seropositivity in the population as the result of immunization with the Lyme disease vaccine and the emergence of new Borrelia species that cause Lyme disease-like illnesses.

Identification of Ehrlichia spp. and Borrelia burgdorferi in Ixodes ticks in the Baltic regions of Russia

The presence and distribution of Ehrlichia spp. and Borrelia burgdorferi sensu lato was demonstrated among ixodid ticks collected in the Baltic regions of Russia, where Lyme borreliosis is endemic. A total of 3,426 Ixodes ricinus and 1,267 Ixodes persulcatus specimens were collected, and dark-field microscopy showed that 265 (11.5%) I. ricinus and 333 (26.3%) I. persulcatus ticks were positive. From these samples, 472 dark-field-positive and 159 dark-field-negative ticks were subjected to PCR and subsequent reverse line blot hybridization. Fifty-four ticks (8.6%) carried Ehrlichia species, and 4 (0.6%) carried ehrlichiae belonging to the Ehrlichia phagocytophila complex, which includes the human granulocytic ehrlichiosis agent. The E. phagocytophila complex and an Ehrlichia-like species were detected only in I. ricinus whereas Ehrlichia muris was found exclusively in I. persulcatus, indicating a possible vector-specific infection. Borrelia garinii was found predominantly in I. persulcatus, but Borrelia afzelii was evenly distributed among the two tick species. Only two I. ricinus ticks carried B. burgdorferi sensu stricto, while Borrelia valaisiana and a newly identified B. afzelii-like species were found in 1.7 and 2.5% of all ticks, respectively. Of the dark-field-positive ticks, only 64.8% yielded a Borrelia PCR product, indicating that dark-field microscopy may detect organisms other than B. burgdorferi sensu lato. These observations show that the agent of human granulocytic ehrlichiosis may be present in ticks in the Baltic regions of Russia and that clinicians should be aware of this agent as a cause of febrile disease.

Biodiversity series: The function of biodiversity in the ecology of vector-borne zoonotic diseases

This is a critical evaluation of the influence of species diversity within communities of vertebrates on the risk of human exposure to vector-borne zoonoses. Vertebrates serve as natural reservoirs of many disease agents (viral, bacterial, protozoal) that are transmitted to humans by blood-feeding arthropod vectors. We describe the natural history of the Lyme disease zoonosis to illustrate interactions among pathogens, vectors, vertebrate hosts, and risk to humans. We then describe how the presence of a diverse assemblage of vertebrates can dilute the impact of the principal reservoir (the white-footed mouse, Peromyscus leucopus) of Lyme disease spirochetes (Borrelia burgdorferi), thereby reducing the disease risk to humans. Exploring the logic of what we call the dilution effect reveals four conditions that are necessary for it to apply generally to vector-borne zoonoses: (1) the feeding habits of the vector are generalized; (2) the pathogen is acquired by the vector from hosts (as opposed to exclusively transovarial transmission); (3) reservoir competence (the ability of a particular host species to infect a vector) varies among host species; and (4) the most competent reservoir host tends to be a community dominant, as defined by the proportion of the tick population fed by that species. When these conditions are met, vertebrate communities with high species diversity will contain a greater proportion of incompetent reservoir hosts that deflect vector meals away from the most competent reservoirs, thereby reducing infection prevalence and disease risk. Incorporating the likelihood that the abundance of competent reservoirs is reduced in more diverse communities, owing to the presence of predators and competitors, reinforces the impact of the dilution effect on the density of infected vectors. A review of the literature reveals the generality, though not the universality, of these conditions, which suggests that the effects of diversity on disease risk may be widespread. Issues in need of further exploration include (i) the relative importance of diversity per se versus fluctuating numbers of particular species; (ii) the relevance of species richness versus evenness to the dilution effect; (iii) whether the dilution effect operates at both local and regional scales; and (iv) the shape of empirically determined curves relating diversity to measures of disease risk. Further studies linking community ecology with epidemiology are warranted.

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.