Lyme borreliosis: a European perspective on diagnosis and clinical management

Infection agents of Didelphidae (Didelphimorphia) of Brazil: an underestimated matter in zoonoses research

Zoonoses are diseases or infections naturally transmissible from vertebrate animals to humans, and can be bacterial, viral or parasitic. The growth of urbanization, industrialization and the advance of agriculture and livestock facilitate the spread of infectious and parasitic agents from wild animals to the human population and to their domestic animals. Among the various reservoirs of zoonotic agents, we find that didelphid species, due to their high capacity for adaptation in urban environments, as an important study case. We reviewed the literature data on the pathogens, including with zoonotic potential of marsupial species occurring in Brazil, accounted for infections by agents that we categorized into Bacteria, Viruses, Protozoa, and Helminths. Aiming identifies possible knowledge gaps, we also surveyed the origin of studied samples and the institutions leading the researches on host didelphids. Among the hosts, the genus Didelphis in the cycles of these agents stands out. Moreover, we found that the majority of reported cases are in the Southeastern Brazil, mean the data from other Brazilian localities and didelphid species could be underestimated. Most studies took place in graduate programs of public research institutions, emphasizing the importance of the funding public research for the Brazilian scientific development.

CXCL13 in laboratory diagnosis of Lyme neuroborreliosis-the performance of the recomBead and ReaScan CXCL13 assays in human cerebrospinal fluid samples

The chemokine CXCL13 is used as complement to serology in the diagnostics of Lyme neuroborreliosis (LNB). We evaluated and compared the semi-quantitative, cassette-based ReaScan CXCL13 assay with the quantitative recomBead CXCL13 assay using a collection of 209 cerebrospinal fluid samples. The categorical agreement between results interpreted as negative, grey zone, and positive by the two methods was 87%. The diagnostic sensitivity was higher using the recomBead assay, whereas specificity was higher using ReaScan. Few manual steps, and a short turn-around time with no batching of samples makes the ReaScan CXCL13 assay an attractive complement to serology in the diagnostics of LNB.

Rejection of the name Borreliella and all proposed species comb. nov. placed therein

Rejection (nomen rejiciendum) of the name Borreliella and all new combinations therein is being requested on grounds of risk to human health and patient safety (Principle 1, subprinciple 2 and Rule 56a) and violation to aim for stability of names, to avoid useless creation of names (Principle 1, subprinciple 1 and 3) and that names should not be changed without sufficient reason (Principle 9 of the International Code of Nomenclature of Prokaryotes).

A Novel Rapid Sample Preparation Method for MALDI-TOF MS Permits Borrelia burgdorferi Sensu Lato Species and Isolate Differentiation

The genus Borrelia comprises vector-borne bacterial pathogens that can severely affect human and animal health. Members of the Borrelia burgdorferi sensu lato species complex can cause Lyme borreliosis, one of the most common vector-borne diseases in the Northern hemisphere. Besides, members of the relapsing fever group of spirochetes can cause tick-borne relapsing fever in humans and various febrile illnesses in animals in tropical, subtropical and temperate regions. Borrelia spp. organisms are fastidious to cultivate and to maintain in vitro, and therefore, difficult to work with in the laboratory. Currently, borrelia identification is mainly performed using PCR and DNA sequencing methods, which can be complicated/frustrating on complex DNA templates and may still be relatively expensive. Alternative techniques such as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) are not well established for Borrelia spp., although this technique is currently one of the most used techniques for rapid identification of bacteria in microbiological diagnostic laboratories. This is mainly due to unsatisfactory results obtained by use of simple sample preparation techniques and medium-contamination obscuring the mass spectra. In addition, comprehensive libraries for Borrelia spp. MALDI-TOF MS have yet to be established. In this study, we developed a new filter-based chemical extraction technique that allows measurement of high quality Borrelia spp. spectra from less than 100,000 bacteria per spot in MALDI-TOF MS. We used 49 isolates of 13 different species to produce the largest mass-library for Borrelia spp. so far and to validate the protocol. The library was successfully established and identifies >96% of used isolates correctly to species level. Cluster analysis on the sum spectra was applied to all the different isolates, which resulted in tight cluster generation for most species. Comparative analysis of the generated cluster to a phylogeny based on concatenated multi-locus sequence typing genes provided a surprising homology. Our data demonstrate that the technique described here can be used for fast and reliable species and strain typing within the borrelia complex.

Guidelines for diagnosis and treatment in neurology - Lyme neuroborreliosis

Lyme borreliosis is the most common tick-borne infectious disease in Europe. A neurological manifestation occurs in 3–15% of infections and can manifest as polyradiculitis, meningitis and (rarely) encephalomyelitis.

This S3 guideline is directed at physicians in private practices and clinics who treat Lyme neuroborreliosis in children and adults.

Twenty AWMF member societies, the Robert Koch Institute, the German Borreliosis Society and three patient organisations participated in its development. A systematic review and assessment of the literature was conducted by the German Cochrane Centre, Freiburg (Cochrane Germany).

The main objectives of this guideline are to define the disease and to give recommendations for the confirmation of a clinically suspected diagnosis by laboratory testing, antibiotic therapy, differential diagnostic testing and prevention.

Lyme Disease Frontiers: Reconciling Borrelia Biology and Clinical Conundrums

Lyme disease is a complex tick-borne zoonosis that poses an escalating public health threat in several parts of the world, despite sophisticated healthcare infrastructure and decades of effort to address the problem. Concepts like the true burden of the illness, from incidence rates to longstanding consequences of infection, and optimal case management, also remain shrouded in controversy. At the heart of this multidisciplinary issue are the causative spirochetal pathogens belonging to the Borrelia Lyme complex. Their unusual physiology and versatile lifestyle have challenged microbiologists, and may also hold the key to unlocking mysteries of the disease. The goal of this review is therefore to integrate established and emerging concepts of Borrelia biology and pathogenesis, and position them in the broader context of biomedical research and clinical practice. We begin by considering the conventions around diagnosing and characterizing Lyme disease that have served as a conceptual framework for the discipline. We then explore virulence from the perspective of both host (genetic and environmental predispositions) and pathogen (serotypes, dissemination, and immune modulation), as well as considering antimicrobial strategies (lab methodology, resistance, persistence, and clinical application), and borrelial adaptations of hypothesized medical significance (phenotypic plasticity or pleomorphy).

Lyme Neuroborreliosis - The Mystifying Pitfall: "Neuropathology and Current Therapeutics"

Lyme's Disease (LD) is a severe, rapidly growing, broad spectrum chronic infection caused by the bacterium 'Borrelia (B.) burgdorferi', which can be easily transmitted through the bite of certain species of ticks. The prevalence of LD is swiftly mounting in the present scenario in many countries from species to species. Although Lyme's infection is now detectable via serologic examination of early and late Lyme neuroborreliosis (LNB), the management of persistent symptoms is still fraught with quora of doubt and debate. LD is a multisystem spirochete which results after the dissemination of B. burgdorferi from a dermal inoculation site after a tick bite. Lyme's infection can easily get transmitted to the central nervous system and develop various neurological symptoms due to inflammation and an autoimmune response from body may lead to life-threatening "Lyme Borreliosis". The neurological symptoms are well mixed in presentation, late and confusing to get differentiated easily from other diseases. The use of antibiotics in post Lyme infection with neurological complications is still a topic of debate. Babesiosisstates, and human ehrlichiosis' the two other diseases, are associated with the same ticks that spread the LD. However, the prevalence of diagnosed human cases is usually much lower than that of actual cases of LD due to misdiagnosis, late diagnosis or undiagnosis at y such lateral neuroinfection stage after the tick bite. The current review focuses on the molecular neuropathology and current advancements in LD. There are very few patents or discoveries made on borrelia infection, drawing attention towards more focused and targeted research for the cure.

The chemokine CXCL13 in cerebrospinal fluid in children with Lyme neuroborreliosis

Anti-Borrelia antibodies in the cerebrospinal fluid (CSF) are required for definite diagnosis of Lyme neuroborreliosis (LNB). However, children often present with early LNB, and antibody production in the CSF may not be demonstrated. Recent studies have suggested the chemokine CXCL13 to be an early marker for LNB. The aim of the study was to evaluate CXCL13 for laboratory diagnosis in pediatric LNB patients and to evaluate the association with pleocytosis in CSF, clinical features, and recovery. CSF samples were collected from LNB patients, classified as definite LNB (n = 44) or possible LNB (n = 22), and controls classified as non-LNB (n = 102) or other specific diagnoses (n = 23). CSF samples were analyzed with the recomBead CXCL13 assay (Mikrogen Diagnostik, Germany), cut-off 160 pg/mL. CXCL13 was significantly higher in LNB patients compared to controls (p < 0.001). Among LNB patients, 58/66 had elevated CXCL13, and among controls, 111/125 had CXCL13 levels under cut-off (sensitivity 88%, specificity 89%). In LNB patients with pleocytosis but no detectable anti-Borrelia antibodies in CSF (possible LNB), CXCL13 was elevated in 16/22 (73%). A weak correlation between CXCL13 and pleocytosis in CSF was found in LNB patients (Rho = 0.46, p < 0.01), but no differences in CXCL13 levels in relation to specific clinical features. In conclusion, CXCL13 is elevated in CSF in children with LNB, showing acceptable sensitivity and specificity. In patients with possible LNB, CXCL13 was elevated in a majority of cases (73%) and is suggested as a complementary diagnostic tool in pediatric LNB patients. CXCL13 was not associated with specific clinical features or recovery.

The recomBead Borrelia antibody index, CXCL13 and total IgM index for laboratory diagnosis of Lyme neuroborreliosis in children

For laboratory diagnostics of Lyme neuroborreliosis (LNB), the recomBead Borrelia antibody index (AI) assay has shown promising results in a mixed age population, but has not previously been evaluated with specific focus on paediatric patients. The aim of the study was to evaluate the recomBead Borrelia AI assay in cerebrospinal fluid (CSF) for the laboratory diagnosis of LNB in children. We also wanted to explore whether early markers, such as CXCL13 in CSF and/or total IgM index could be useful as complementary diagnostic tools. Children being evaluated for LNB in a Swedish Lyme endemic area were included in the study (n = 146). Serum and CSF were collected on admission. Patients with other specific diagnoses were controls (n = 15). The recomBead Borrelia AI assay and the recomBead CXCL13 assay (Mikrogen) were applied together with total IgM index. The overall sensitivity for recomBead Borrelia AI (IgM and IgG together) was 74% and the specificity was 97%. However, the highest sensitivity (91%) at an acceptable level of specificity (90%) was obtained by recomBead Borrelia AI together with CXCL13 and total IgM index, showing a positive predictive value of 84% and a negative predictive value of 95%. Thus, the recomBead Borrelia AI assay performs with moderate sensitivity and high specificity in paediatric LNB patients. The major advantage seems to be increased sensitivity in the possible LNB group compared to the IDEIA assay. The diagnostic sensitivity may be further increased by using a combination of early markers, such as CXCL13 in CSF and total IgM index.

Lost in plasmids: next generation sequencing and the complex genome of the tick-borne pathogen Borrelia burgdorferi

Background

Borrelia (B.) burgdorferi sensu lato, including the tick-transmitted agents of human Lyme borreliosis, have particularly complex genomes, consisting of a linear main chromosome and numerous linear and circular plasmids. The number and structure of plasmids is variable even in strains within a single genospecies. Genes on these plasmids are known to play essential roles in virulence and pathogenicity as well as host and vector associations. For this reason, it is essential to explore methods for rapid and reliable characterisation of molecular level changes on plasmids.

In this study we used three strains: a low passage isolate of B. burgdorferi sensu stricto strain B31(−NRZ) and two closely related strains (PAli and PAbe) that were isolated from human patients. Sequences of these strains were compared to the previously sequenced reference strain B31 (available in GenBank) to obtain proof-of-principle information on the suitability of next generation sequencing (NGS) library construction and sequencing methods on the assembly of bacterial plasmids. We tested the effectiveness of different short read assemblers on Illumina sequences, and of long read generation methods on sequence data from Pacific Bioscience single-molecule real-time (SMRT) and nanopore (Oxford Nanopore Technologies) sequencing technology.

Results

Inclusion of mate pair library reads improved the assembly in some plasmids as did prior enrichment of plasmids. While cp32 plasmids remained refractory to assembly using only short reads they were effectively assembled by long read sequencing methods. The long read SMRT and nanopore sequences came, however, at the cost of indels (insertions or deletions) appearing in an unpredictable manner. Using long and short read technologies together allowed us to show that the three B. burgdorferi s.s. strains investigated here, whilst having similar plasmid structures to each other (apart from fusion of cp32 plasmids), differed significantly from the reference strain B31-GB, especially in the case of cp32 plasmids.

Conclusion

Short read methods are sufficient to assemble the main chromosome and many of the plasmids in B. burgdorferi. However, a combination of short and long read sequencing methods is essential for proper assembly of all plasmids including cp32 and thus, for gaining an understanding of host- or vector adaptations. An important conclusion from our work is that the evolution of Borrelia plasmids appears to be dynamic. This has important implications for the development of useful research strategies to monitor the risk of Lyme disease occurrence and how to medically manage it.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-017-3804-5) contains supplementary material, which is available to authorized users.

Phylogeographic Structure of the White-Footed Mouse and the Deer Mouse, Two Lyme Disease Reservoir Hosts in Québec

Modification of a species range is one of many consequences of climate change and is driving the emergence of Lyme disease in eastern Canada. The primary reservoir host of the bacteria responsible for Lyme disease, Borrelia burgdorferi, is the white-footed mouse (Peromyscus leucopus), whose range is rapidly shifting north into southern Québec. The deer mouse, P. maniculatus, is occurring over most Québec province and is a less competent host for B. burgdorferi. Here, we compared the phylogeographic structure of both Peromyscus species in Québec. Using a combination of multiple mitochondrial DNA markers and phylogeographic methods, we detected an ongoing and rapid expansion of P. leucopus, while P. maniculatus appears more stable. Haplotype and populations networks indicated that populations of P. maniculatus exhibit more genetic structure than P. leucopus across the study area. Furthermore, significant and consistent genetic divergences between populations of the two species on both sides of the St. Lawrence River suggest that distinct lineages of P. leucopus and P. maniculatus with different ancestral origins colonized Southern Québec following the Last Glacial Maximum. The phylogeographic structure of pathogens is expected to mirror the structure observed in their reservoir hosts. As different strains of Borrelia burgdorferi may be associated with different levels of pathogenicity and immune responses of their hosts, our results are helpful at better understanding the pattern of spread of Lyme disease in a zone of emergence, and associated risk for human populations.

NGS population genetics analyses reveal divergent evolution of a Lyme Borreliosis agent in Europe and Asia

Borrelia bavariensis is a recently described agent of Lyme disease within the B. burgdorferi sensu lato species complex and exhibits a strong capacity for human pathogenicity. B. bavariensis strains are widely distributed in Eurasia spanning the distribution range of the tick vectors Ixodes persulcatus and I. ricinus. It has been suggested that B. bavariensis forms two populations, one of which arose through vector adaptation and geographic expansion. We have performed phylogenetic and population genetic analyses with next-generation sequencing data of 26 strains of B. bavariensis targeting the main linear chromosome and two plasmids (lp54, cp26). A very low number of single nucleotide polymorphisms (SNPs) was found in the European population and a deep branching pattern between European and Asian B. bavariensis was observed in all phylogenies. The results confirm the population structure of B. bavariensis and strongly support the hypothesis of clonal expansion of the European population of B. bavariensis. In addition, signals of positive selection identified in the populations further support the hypothesis that the European population of B. bavariensis likely underwent vector adaptation in its recent evolutionary history. Identified genes represent promising candidates for experimental vector adaptation studies. Thus, this species forms a very good model to study vector adaptation, which is known to play an important role in the geographic distribution of B. burgdorferi. Analysis of well known virulence determinants that are attributed to severity of clinical manifestation in B. burgdorferi s.s. revealed no variation within the European population of B. bavariensis, underlining the importance of including various Borrelia species into investigations that aim to understand the pathogenesis of Lyme disease agents.

[Diagnosis and treatment of Lyme arthritis. Recommendations of the Pharmacotherapy Commission of the Deutsche Gesellschaft für Rheumatologie (German Society for Rheumatology)]

These guidelines summarize the current evidence for diagnosis and treatment of Lyme arthritis and the most frequent skin manifestations of Borrelia burgdorferi infections. Lyme arthritis is a monoarticular or oligoarticular form of arthritis that typically involves the knee. A positive enzyme-linked immunosorbent assay (ELISA) for IgG antibodies should be followed by an IgG immunoblot. A positive PCR test from synovial fluid adds increased diagnostic certainty. Serum positivity for antibodies to Borrelia burgdorferi without typical symptoms does not justify antibiotic treatment. Oral antibiotic treatment for erythema migrans is recommended using doxycycline, 200 mg once per day for 10-21 days, alternative choices are amoxicillin, cefuroxime and azithromycin. For children below 8 years of age, amoxicillin is recommended.Lyme arthritis can usually be successfully treated with orally administered antimicrobial agents. Doxycycline, 1 × 200 or 2 × 100 mg for 30 days is the antibiotic agent of choice. Amoxicillin (3 × 500-1000 mg) can be alternatively chosen. Patients who have persistent or recurrent joint swelling after a recommended course of oral antibiotic therapy should be treated intravenously. In this situation, ceftriaxone at 2 g per day for 14-21 days is recommended. There is no evidence to recommend long-term and combined treatments.

Borrelial pseudolymphoma of the nose

A 52-year-old Colombian woman, a patient with psoriasis, undergoing phototherapy with (ultraviolet B narrowband) UVBnb, presented with a symptomless solitary diffuse erythaematous plaque on her nose for 3 months. Initially, she was treated with pimecrolimus 1% cream for 8 weeks, which was then combined with metronidazole cream for 4 weeks, with the initial diagnosis of UV-triggered rosacea, without improvement. A punch biopsy was performed and the histology showed a pseudolymphomatous reaction. The diagnosis of nasal pseudolymphoma of borreliosis was confirmed with PCR. The lesion completely resolved following oral doxycycline therapy.

Multiple infections of rodents with zoonotic pathogens in Austria

Rodents are important reservoirs for a large number of zoonotic pathogens. We examined the occurrence of 11 viral, bacterial, and parasitic agents in rodent populations in Austria, including three different hantaviruses, lymphocytic choriomeningitis virus, orthopox virus, Leptospira spp., Borrelia spp., Rickettsia spp., Bartonella spp., Coxiella burnetii, and Toxoplasma gondii. In 2008, 110 rodents of four species (40 Clethrionomys glareolus, 29 Apodemus flavicollis, 26 Apodemus sylvaticus, and 15 Microtus arvalis) were trapped at two rural sites in Lower Austria. Chest cavity fluid and samples of lung, spleen, kidney, liver, brain, and ear pinna skin were collected. We screened selected tissue samples for hantaviruses, lymphocytic choriomeningitis virus, orthopox viruses, Leptospira, Borrelia, Rickettsia, Bartonella spp., C. burnetii, and T. gondii by RT-PCR/PCR and detected nucleic acids of Tula hantavirus, Leptospira spp., Borrelia afzelii, Rickettsia spp., and different Bartonella species. Serological investigations were performed for hantaviruses, lymphocytic choriomeningitis virus, orthopox viruses, and Rickettsia spp. Here, Dobrava-Belgrade hantavirus-, Tula hantavirus-, lymphocytic choriomeningitis virus-, orthopox virus-, and rickettsia-specific antibodies were demonstrated. Puumala hantavirus, C. burnetii, and T. gondii were neither detected by RT-PCR/PCR nor by serological methods. In addition, multiple infections with up to three pathogens were shown in nine animals of three rodent species from different trapping sites. In conclusion, these results show that rodents in Austria may host multiple zoonotic pathogens. Our observation raises important questions regarding the interactions of different pathogens in the host, the countermeasures of the host's immune system, the impact of the host-pathogen interaction on the fitness of the host, and the spread of infectious agents among wild rodents and from those to other animals or humans.

CXCL13 and neopterin concentrations in cerebrospinal fluid of patients with Lyme neuroborreliosis and other diseases that cause neuroinflammation

BACKGROUND

Laboratory diagnosis of Lyme neuroborreliosis (LNB) is partly based on the detection of intrathecal Borrelia burgdorferi-specific antibody production (increased antibody index (AI)). However, AI can be negative in patients with early LNB and, conversely, can remain elevated for months after antibiotic treatment. Recent studies suggested that the chemokine CXCL13 in the cerebrospinal fluid (CSF) is a biomarker for active LNB. Also, CSF neopterin-level determination has been used to assess the degree of neuroinflammation in a wide variety of diseases.

METHODS

CXCL13 concentrations were analyzed in CSF samples of 366 retrospectively identified individuals. The samples represented pretreatment LNB (38 patients), non-LNB comparison patients, tick-borne encephalitis, central nervous system (CNS) varicella zoster virus infection, CNS herpes simplex virus infection, CNS HHV6 infection, CNS enterovirus infection, and untreated neurosyphilis. The panel included also samples from patients with multiple sclerosis and other neuroinflammatory conditions. Of the LNB patients, 24 posttreatment CSF samples were available for CXCL13 analysis. Neopterin concentrations were determined in a subset of these samples.

RESULTS

The CXCL13 concentrations in CSF samples of untreated LNB patients were significantly higher (median, 6,480 pg/ml) than the concentrations in the non-LNB group (median, <7.8 pg/ml), viral CNS infection samples (median, <7.8 pg/ml), or samples from patients with noninfectious neuroinflammatory conditions (median, <7.8 pg/ml). The use of cut-off 415 pg/ml led to a sensitivity of 100% and specificity of 99.7% for the diagnosis of LNB in these samples. CSF CXCL13 median concentrations declined significantly from 16,770 pg/ml before to 109 pg/ml after the treatment.CSF neopterin concentration was significantly higher among the untreated LNB patients than in the non-LNB group. The use of neopterin concentration 10.6 nM as the cut-off led to a sensitivity of 88.6% and a specificity of 65.0% for the diagnosis of LNB. The CSF neopterin concentrations decreased statistically significantly with the treatment.

CONCLUSIONS

These results clearly indicate that highly elevated CSF CXCL13 levels are strongly associated with untreated LNB. CXCL13 outperformed neopterin and appears to be an excellent biomarker in differentiating LNB from viral CNS infections and from other neuroinflammatory conditions.

Chronic Lyme; diagnostic and therapeutic challenges

In this review, we aim to discuss the definition, clinical and laboratory features, diagnostics, and management of chronic Lyme. Chronic Lyme is a rare condition caused by long-lasting and ongoing infection with the spirochete Borrelia burgdorferi (Bb). The most common manifestations are progressive encephalitis, myelitis, acrodermatitis chronica atrophicans with or without neuropathy, and arthritis. Chronic Lyme is not considered to present with isolated subjective symptoms. Direct detection of Bb has low yield in most manifestations of chronic Lyme, while almost 100% of the cases are seropositive, that is, have detectable Bb IgG antibodies in serum. Detection of Bb antibodies only with Western blot technique and not with ELISA and detection of Bb IgM antibodies without simultaneous detection of Bb IgG antibodies should be considered as seronegativity in patients with long-lasting symptoms. Patients with chronic Lyme in the nervous system (neuroborreliosis) have, with few exceptions, pleocytosis and production of Bb antibodies in their cerebrospinal fluid. Strict guidelines should be applied in diagnostics of chronic Lyme, and several differential diagnoses, including neurological disease, rheumatologic disease, post-Lyme disease syndrome, chronic fatigue syndrome, and psychiatric disease, should be considered in the diagnostic workup. Antibiotic treatment with administration route and dosages according to current guidelines are recommended. Combination antimicrobial therapy or antibiotic courses longer than 4 weeks are not recommended. Patients who attribute their symptoms to chronic Lyme on doubtful basis should be offered a thorough and systematic diagnostic approach, and an open and respectful dialogue.

Future challenges for parasitology: vector control and 'One health' in Europe: the veterinary medicinal view on CVBDs such as tick borreliosis, rickettsiosis and canine leishmaniosis

The medical as well as the veterinary importance of parasitic arthropods or ectoparasites in general terms, is characterized by the primary or secondary impact on the health of humans and companion animals alike. The parasitic arthropods addressed here are those ectoparasites belong to the class of insects, such as fleas and sand flies, or the subclass of acarids, such as ticks. These parasitic arthropods interact intensively with their hosts by blood feeding. Fleas, sand flies and ticks hold the vector capacity to transmit pathogens such as virus, bacteria or protozoa to cats, dogs and humans. The diseases caused by these pathogens are summarized under the terms canine vector-borne diseases (CVBD), feline vector-borne diseases (FVBD) or metazoonoses. In small animal practice, it is important to understand that the transmitted pathogen may either lead to a disease with clinical signs, or more often to asymptomatic, clinically healthy, or silent infections. Blocking of the vector-host interactions, the blood feeding and subsequently the transmission of pathogens during blood feeding is a key element of CVBD control. The focus of this review is on the current knowledge of the epidemiology of parasitic vectors and three important CVBDs they transmit; rickettsiosis, tick borreliosis and canine leishmaniosis from a European perspective, and how veterinary medicine may contribute to the challenges of CVBDs and their control. Prevention of CVBDs is fundamentally based on ectoparasite control. Ectoparasite management in cats and dogs is important not only for the health and well-being of the individual companion animal but for public health in general and is therefore a perfect example of the 'One health' approach.

Enhanced detection of host response antibodies to Borrelia burgdorferi using immuno-PCR

Lyme disease is the fastest-growing zoonotic disease in North America. Current methods for detection of Borrelia burgdorferi infection are challenged by analysis subjectivity and standardization of antigen source. In the present study, we developed an immuno-PCR (iPCR)-based approach employing recombinant in vivo-expressed B. burgdorferi antigens for objective detection of a host immune response to B. burgdorferi infection. iPCR is a liquid-phase protein detection method that combines the sensitivity of PCR with the specificity and versatility of immunoassay-based protocols. Use of magnetic beads coated with intact spirochetes provided effective antigen presentation and allowed detection of host-generated antibodies in experimentally infected mice at day 11 postinoculation, whereas host-generated antibodies were detected at day 14 by enzyme-linked immunosorbent assay (ELISA) and day 21 by immunoblotting. Furthermore, magnetic beads coated with recombinant B. burgdorferi in vivo-expressed antigen OspC or BmpA demonstrated positive detection of host-generated antibodies in mice at day 7 postinoculation with markedly increased iPCR signals above the background, with the quantification cycle (C(q)) value for each sample minus the mean background C(q) plus 3 standard deviations (ΔC(q)) being 4 to 10, whereas ΔC(q) was 2.5 for intact spirochete-coated beads. iPCR demonstrated a strong correlation (Spearman rank correlation = 0.895, P < 0.0001) with a commercial ELISA for detection of host antibodies in human Lyme disease patient sera using the B. burgdorferi VlsE C6 peptide. In addition, iPCR showed potential applicability for direct detection of spirochetes in blood. The results presented here indicate that our iPCR assay has the potential to provide an objective format that can be used for sensitive detection of multiple host response antibodies and isotypes to B. burgdorferi infection.

Inflammatory, vascular, and infectious myelopathies in children

Acute nontraumatic myelopathies of childhood include inflammatory, infectious, and vascular etiologies. Inflammatory immune-mediated disorders of the spinal cord can be categorized as idiopathic isolated transverse myelitis, neuromyelitis optica, and multiple sclerosis. In recent years, human T-cell lymphotropic virus type 1, West Nile virus, enterovirus-71, and Lyme disease have been increasingly recognized as infectious etiologies of myelopathy, and poliomyelitis remains an important etiology in world regions where vaccination programs have not been universally available. Vascular etiologies include vasculopathies (systemic lupus erythematosus, small vessel primary angiitis of the central nervous system), arteriovenous malformations, and spinal cord infarction (fibrocartilaginous embolism, diffuse hypoxic ischemia-mediated infarction). Vascular myelopathies are less common than inflammatory and infectious myelopathies, but are more likely to lead to devastating clinical deficits. Current therapeutic strategies include acute anti-inflammatory treatment and rehabilitation. Stem cell transplantation, nerve graft implantation, and stimulation of endogenous repair mechanisms represent promising strategies for spinal cord repair.

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

Background

Persistent symptoms after treatment of neuroborreliosis (NB) are well-documented, although the causative mechanisms are mainly unknown. The effect of repeated antibiotic treatment has not been studied in detail. The aim of this study was to determine whether: (1) persistent symptoms improve with doxycycline treatment; (2) doxycycline has an influence on systemic cytokine responses, and; (3) improvement of symptoms could be due to doxycycline-mediated immunomodulation.

Methods/Design

15 NB patients with persistent symptoms ≥6 months post-treatment were double-blindly randomized to receive 200 mg of doxycycline or a placebo for three weeks. After a six-week wash-out period, a cross-over with a three-week course of a placebo or doxycycline was conducted. The primary outcome measures were improvement of persistent symptoms assessed by neurological examinations, a symptom severity score and estimation of the quality of life. The secondary outcome measure was changes in systemic cytokine responses.

Results

All 15 patients finished the study. No doxycycline-mediated improvement of post-treatment symptoms or quality of life was observed. Nor could any doxycycline-mediated changes in systemic cytokine responses be detected. The study was completed without any serious adverse events.

Discussion

No doxycycline-mediated improvement of post-treatment symptoms or quality of life was observed. Nor could any doxycycline-mediated changes in systemic cytokine responses be detected. The study was completed without any serious adverse events. To conclude, in this pilot study, doxycycline-treatment did not lead to any improvement of either the persistent symptoms or quality of life in post-NB patients. Accordingly, doxycycline does not seem to be the optimal treatment of diverse persistent symptoms post-NB. However, the results need to be confirmed in larger studies.

Trial registration

NCT01205464 (clinicaltrials.gov)

Pediatric tick-borne infections of the central nervous system in an endemic region of Sweden: a prospective evaluation of clinical manifestations

Tick-borne encephalitis (TBE) and neuroborreliosis (NB) are well-known central nervous system (CNS) infections in children. Childhood tick-borne CNS infections are generally described as mild conditions. However, this view has recently been challenged, and the natural course, including potential sequelae, has been debated. If the diseases present with nonspecific symptoms and signs, some children may elude diagnosis. This study estimates the incidence of symptomatic tick-borne CNS infections in children under medical care and describes the spectrum of manifestations. One hundred twenty-four children with neurologic symptoms attending the Pediatric Emergency Department were included prospectively. Anti-TBE virus and anti-Borrelia serology results were analyzed together with inflammatory parameters in the blood and cerebrospinal fluid. Nearly one fourth of the children with neurologic symptoms were diagnosed with a tick-borne CNS infection (TBE, n = 10 [8%] and NB, n = 21 [16.8%]). In general, these children displayed an indistinct medical history and presented with nonspecific signs such as malaise/fatigue and headache. Diagnosis was based on analysis of acute and convalescent sera. Blood inflammatory parameters were nonspecific and did not contribute to the diagnostics.

CONCLUSION

Pediatric tick-borne CNS infections are unexpectedly common and should be considered in children with unspecific and unexplained acute CNS-related symptoms.

Lyme borreliosis

Borreliosis is an infectious disease caused by spirochetes of the genus Borrelia. Lyme borreliosis, also known as Lyme disease, is a non-contagious infectious disease caused by spirochetes belonging to the complex Borrelia burgdorferi sensu lato and more often transmitted by the bite of infected ticks of the genus Ixodes.The disease is characterized by a varied clinical profile, which can trigger cutaneous, articular, neurological and cardiac manifestations.

Population genetics, taxonomy, phylogeny and evolution of Borrelia burgdorferi sensu lato

In order to understand the population structure and dynamics of bacterial microorganisms, typing systems that accurately reflect the phylogenetic and evolutionary relationship of the agents are required. Over the past 15 years multilocus sequence typing schemes have replaced single locus approaches, giving novel insights into phylogenetic and evolutionary relationships of many bacterial species and facilitating taxonomy. Since 2004, several schemes using multiple loci have been developed to better understand the taxonomy, phylogeny and evolution of Lyme borreliosis spirochetes and in this paper we have reviewed and summarized the progress that has been made for this important group of vector-borne zoonotic bacteria.

Plasmid profile analysis of Portuguese Borrelia lusitaniae strains

Plasmid profiles of 2 Portuguese Borrelia lusitaniae strains, one isolated from a human patient and the other one from an Ixodes ricinus tick, were obtained by pulsed-field gel electrophoresis to evaluate the plasmid diversity in each strain. Overall, a maximum of 6 plasmids were detected that ranged from 19 kb to 76 kb, revealing completely different plasmid profiles from those previously described for other genospecies of B. burgdorferi sensu lato, the causative agents of Lyme borreliosis. The plasmid location of the ospA gene was investigated by hybridization, allowing its allocation to the plasmid of 70 kb instead of the 54 kb linear plasmid described for B. burgdorferi sensu stricto strains.

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

BACKGROUND

Despite the good prognosis of erythema migrans (EM), some patients have persisting symptoms of various character and duration post-treatment. Several factors may affect the clinical outcome of EM, e.g. the early interaction between Borrelia (B.) burgdorferi and the host immune response, the B. burgdorferi genotype, antibiotic treatment as well as other clinical circumstances. Our study was designed to determine whether early cytokine expression in the skin and in peripheral blood in patients with EM is associated with the clinical outcome.

METHODS

A prospective follow-up study of 109 patients with EM was conducted at the Åland Islands, Finland. Symptoms were evaluated at 3, 6, 12 and 24 months post-treatment. Skin biopsies from the EM and healthy skin were immunohistochemically analysed for expression of interleukin (IL)-4, IL-10, IL-12p70 and interferon (IFN)-γ, as well as for B. burgdorferi DNA. Blood samples were analysed for B. burgdorferi antibodies, allergic predisposition and levels of systemic cytokines.

FINDINGS

None of the patients developed late manifestations of Lyme borreliosis. However, at the 6-month follow-up, 7 of 88 patients reported persisting symptoms of diverse character. Compared to asymptomatic patients, these 7 patients showed decreased expression of the Th1-associated cytokine IFN-γ in the EM biopsies (p=0.003). B. afzelii DNA was found in 48%, B. garinii in 15% and B. burgdorferi sensu stricto in 1% of the EM biopsies, and species distribution was the same in patients with and without post-treatment symptoms. The two groups did not differ regarding baseline patient characteristics, B. burgdorferi antibodies, allergic predisposition or systemic cytokine levels.

CONCLUSION

Patients with persisting symptoms following an EM show a decreased Th1-type inflammatory response in infected skin early during the infection, which might reflect a dysregulation of the early immune response. This finding supports the importance of an early, local Th1-type response for optimal resolution of LB.

A clear and present danger: tick-borne diseases in Europe

Ticks can transmit a variety of viruses, bacteria or parasites that can cause serious infections or conditions in humans and animals. While tick-borne diseases are becoming an increasing and serious problem in Europe, tick-borne diseases are also responsible for major depressions in livestock production and mortality in sub-Saharan Africa, Latin America and Asia. This review will focus on the most important circulating tick-transmitted pathogens in Europe (Borrelia spp., Anaplasma phagocytophilum, Babesia spp., tick-borne encephalitis virus, Rickettsia spp. and Crimean-Congo hemorrhagic fever virus).