Skin microbiota secretomes modulate cutaneous innate immunity against Borrelia burgdorferi s.s

In Lyme borreliosis, the skin constitutes a major interface for the host, the bacteria and the tick. Skin immunity is provided by specialized immune cells but also by the resident cells: the keratinocytes and the fibroblasts. Discoveries on the role of the microbiome in the modulation of skin inflammation and immunity have reinforced the potential importance of the skin in vector-borne diseases. In this study, we analyzed in vitro the interaction of human primary keratinocytes and fibroblasts with Borrelia burgdorferi sensu stricto N40 in presence or absence of bacterial commensal supernatants. We aimed to highlight the role of resident skin cells and skin microbiome on the inflammation induced by B. burgdorferi s.s.. The secretomes of Staphylococcus epidermidis, Corynebacterium striatum and Cutibacterium acnes showed an overall increase in the expression of IL-8, CXCL1, MCP-1 and SOD-2 by fibroblasts, and of IL-8, CXCL1, MCP-1 and hBD-2 in the undifferentiated keratinocytes. Commensal bacteria showed a repressive effect on the expression of IL-8, CXCL1 and MCP-1 by differentiated keratinocytes. Besides the inflammatory effect observed in the presence of Borrelia on all cell types, the cutaneous microbiome appears to promote a rapid innate response of resident skin cells during the onset of Borrelia infection.

Seroprevalence for Borrelia burgdorferi sensu lato and tick-borne encephalitis virus antibodies and associated risk factors among forestry workers in northern France, 2019 to 2020

BackgroundLyme borreliosis (LB) is the most common tick-borne disease (TBD) in France. Forestry workers are at high risk of TBD because of frequent exposure to tick bites.AimWe aimed to estimate the seroprevalence of Borrelia burgdorferi sensu lato and tick-borne encephalitis virus (TBEV) antibodies among forestry workers in northern France. We compared seroprevalence by geographical area and assessed factors associated with seropositivity.MethodsBetween 2019 and 2020, we conducted a randomised cross-sectional seroprevalence survey. Borrelia burgdorferi sl seropositivity was defined as positive ELISA and positive or equivocal result in western blot. Seropositivity for TBEV was defined as positive result from two ELISA tests, confirmed by serum neutralisation. We calculated weighted seroprevalence and adjusted prevalence ratios to determine association between potential risk factors and seropositivity.ResultsA total of 1,778 forestry workers participated. Seroprevalence for B. burgdorferi sl was 15.5% (95% confidence interval (CI): 13.9-17.3), 3.5 times higher in the eastern regions than in the western and increased with seniority and with weekly time in a forest environment. Seroprevalence was 2.5 times higher in forestry workers reporting a tick bite during past years and reporting usually not removing ticks rapidly. Seroprevalence for TBEV was 0.14% (95% CI: 0.05-0.42).ConclusionWe assessed for the first time seroprevalence of B. burgdorferi sl and TBEV antibodies among forestry workers in northern France. These results will be used, together with data on LB and tick-borne encephalitis (TBE) incidence and on exposure to tick-bites, to target prevention programmes.

Impact of Different Anthropogenic Environments on Ticks and Tick-Associated Pathogens in Alsace, a French Region Highly Endemic for Tick-Borne Diseases

Ticks and tick-borne diseases have spread over the last decades. In parallel, the incidence in humans, accidental hosts for most of these zoonotic diseases, has increased. This epidemiological intensification can be associated with anthropogenic alterations of forest ecosystems and animal biodiversity, but also with socioeconomic changes. Their proliferation is largely due to human-induced effects on the factors that favor the circulation of these infectious agents. We selected different types of anthropogenic environments in Alsace, a region endemic for tick-borne diseases in France, to better understand the impact of human interventions on tick populations and tick-borne disease incidence. Ticks were collected in one golf course, three urban parks, one mid-mountain forest, and one alluvial forest that is currently part of a protected natural area. Ixodes ricinus was found primarily in humid vegetation, which is favorable for tick survival, such as grounds populated with trees and covered with leaf litter. We also observed that reforestation and high animal biodiversity in a protected area such as the alluvial forest led to a greater number of ticks, including both Ixodes ricinus and Dermacentor reticulatus, as well as to a higher prevalence of pathogens such as Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Borrelia miyamotoi, and Rickettsia raoulti.

E-learning versus face-to-face training: Comparison of two learning methods for Lyme borreliosis

OBJECTIVES

To compare two learning methods for Lyme disease (e-learning versus face-to-face training) to assess knowledge and know-how.

METHODS

The study population was volunteer general medicine residents and family physicians (FP). Face-to-face training on Lyme disease was offered to each group. E-learning training was then offered to those who had not attended the face-to-face training. Theoretical knowledge was assessed by an identical pre- and post-test questionnaire and know-how by a script concordance test.

RESULTS

Seventy learners (47 FPs and 23 general medicine residents) were included in the face-to-face training group and 61 (33 FPs and 28 general medicine residents) in the e-learning group. The pre- and post-test scores were significantly improved in the FP group (difference of 29.3±1.9 [P<0.0001] out of 100) as well as in the general medicine resident group (difference of 38.2±2.7 [P<0.0001] out of 100). E-learning was more effective than face-to-face training, particularly among general medicine residents (progression of mean difference of 44.3±3.4/100 vs. 30.9±4.0/100; P=0.0138) and to a lesser extent among FPs (progression of 25.3±2.3/100 vs. 31.9±2.7/100; P=0.0757). Forty-six script concordance tests were completed by FPs and 20 by general medicine residents. Script concordance test results did not seem significant between the subgroups.

CONCLUSIONS

E-learning seems to be a good alternative to face-to-face training for Lyme disease. It seems to be more effective than face-to-face training for the acquisition of theoretical knowledge. The script concordance test evaluation of know-how did not show any difference between the two learning methods.

Differences in infection control and diagnostic measures for multidrug-resistant organisms in the tristate area of France, Germany and Switzerland in 2019 - survey results from the RH(E)IN-CARE network

BACKGROUND

Multidrug-resistant organisms (MDROs) are a public health threat. Single-centre interventions, however, are likely to fail in the long term, as patients are commonly transferred between institutions given the economic integration across borders. A transnational approach targeting larger regions is needed to plan overarching sets of interventions. Here, we aim to describe differences in diagnostic and infection prevention and control (IPC) measures in the fight against MDROs.

METHODS

In 2019, we systematically assessed diagnostic algorithms and IPC measures implemented for detection and control of MDROs at three tertiary academic care centres (Freiburg; Strasbourg; Basel). Data were collected using a standardised data collection sheet to be filled in by every centre. Uncertainties were clarified by direct contact via telephone or email with the data supplier. Internal validity was checked by at least two researchers independently filling in the survey.

RESULTS

All centres have established a primarily culture-based, rather than a nucleic acid amplification-based approach for detection of MDROs (i.e., vancomycin-resistant Enterococci [VRE], methicillin-resistant Staphylococcus aureus [MRSA], extended-spectrum beta-lactamase-producing Enterobacteriaceae [ESBL], carbapenemase-producing and carbapenem-resistant Gram-negatives [CPGN/CRGN]). IPC measures differed greatly across all centres. High-risk patients are screened for most MDROs on intensive care unit (ICU) admission in all centres; only the French centre is screening all patients admitted to the ICU for VRE, MRSA and ESBL. Patients colonised/infected by MRSA, quinolone-resistant ESBL Klebsiella spp. and CPGN/CRGN are isolated everywhere, whereas patients colonised/infected by VRE and ESBL are usually not isolated in the German centre.

CONCLUSIONS

In contrast to the French and Swiss centres, the German centre no longer uses isolation measures to control VRE and quinolone-susceptible ESBL. Overall, the French centre is more focused on intercepting MDRO transmission from outside, whereas the German and Swiss centres are more focused on intercepting endemic MDRO transmission. These findings point to important challenges regarding future attempts to standardise IPC measures across borders. &nbsp; &nbsp.

Microbiological Outcomes Associated With Low Leukocyte Counts in Cerebrospinal Fluid

The significance of low leukocyte counts in cerebrospinal fluid (CSF) remains unclear. We performed a 2-year retrospective study to examine microbiological outcomes associated with CSF leukocytes at 6–10/mm³. Of the 178 samples examined, we detected positive results for 11 samples, including 5 cases of tick-borne encephalitis virus infection.

Proteomic as an Exploratory Approach to Develop Vaccines Against Tick-Borne Diseases Using Lyme Borreliosis as a Test Case

Tick-borne diseases affecting humans and animals are on the rise worldwide. Vaccines constitute an effective control measure, but very few are available. We selected Lyme borreliosis, a bacterial infection transmitted by the hard tick Ixodes, to validate a new concept to identify vaccine candidates. This disease is the most common tick-borne disease in the Northern Hemisphere. Although attempts to develop a vaccine exist, none have been successfully marketed. In tick-borne diseases, the skin constitutes a very specific environment encountered by the pathogen during its co-inoculation with tick saliva. In a mouse model, we developed a proteomic approach to identify vaccine candidates in skin biopsies. We identified 30 bacterial proteins after syringe inoculation or tick inoculation of bacteria. Discovery proteomics using mass spectrometry might be used in various tick-borne diseases to identify pathogen proteins with early skin expression. It should help to better develop sub-unit vaccines based on a cocktail of several antigens, associated with effective adjuvant and delivery systems of antigens. In all vector-borne diseases, the skin deserves further investigation to better define its role in the elaboration of protective immunity against pathogens.

Effects of topical corticosteroids and lidocaine on Borrelia burgdorferi sensu lato in mouse skin: potential impact to human clinical trials

Lyme borreliosis is the most prevalent vector-borne disease in northern hemisphere. Borrelia burgdorferi sensu lato spirochetes are transmitted by Ixodes species ticks. During a blood meal, these spirochetes are inoculated into the skin where they multiply and often spread to various target organs: disseminated skin sites, the central nervous system, the heart and large joints. The usual diagnosis of this disease relies on serological tests. However, in patients presenting persistent clinical manifestations, this indirect diagnosis is not capable of detecting an active infection. If the serological tests are positive, it only proves that exposure of an individual to Lyme spirochetes had occurred. Although culture and quantitative PCR detect active infection, currently used tests are not sensitive enough for wide-ranging applications. Animal models have shown that B. burgdorferi persists in the skin. We present here our targeted proteomics results using infected mouse skin biopsies that facilitate detection of this pathogen. We have employed several novel approaches in this study. First, the effect of lidocaine, a local anesthetic used for human skin biopsy, on B. burgdorferi presence was measured. We further determined the impact of topical corticosteroids to reactivate Borrelia locally in the skin. This local immunosuppressive compound helps follow-up detection of spirochetes by proteomic analysis of Borrelia present in the skin. This approach could be developed as a novel diagnostic test for active Lyme borreliosis in patients presenting disseminated persistent infection. Although our results using topical corticosteroids in mice are highly promising for recovery of spirochetes, further optimization will be needed to translate this strategy for diagnosis of Lyme disease in patients.

Value of PCR, Serology, and Blood Smears for Human Granulocytic Anaplasmosis Diagnosis, France

We prospectively examined the effectiveness of diagnostic tests for anaplasmosis using patients with suspected diagnoses in France. PCR (sensitivity 0.74, specificity 1) was the best-suited test. Serology had a lower specificity but higher sensitivity when testing acute and convalescent samples. PCR and serology should be used in combination for anaplasmosis diagnosis.

Unconventional diagnostic tests for Lyme borreliosis: a systematic review

BACKGROUND

Lyme borreliosis (LB) diagnosis currently relies mainly on serological tests and sometimes PCR or culture. However, other biological assays are being developed to try to improve Borrelia-infection diagnosis and/or monitoring.

OBJECTIVES

To analyse available data on these unconventional LB diagnostic assays through a systematic literature review.

METHODS

We searched PubMed and Cochrane Library databases according to the PRISMA-DTA method and the Cochrane Handbook for Systematic Reviews of Interventions. We analysed controlled and uncontrolled studies (published 1983-2018) on biological tests for adults to diagnose LB according to the European Study Group for Lyme Borreliosis or the Infectious Diseases Society of America definitions, or identify strongly suspected LB. Two independent readers evaluated study eligibility and extracted data from relevant study reports; a third reader analysed full texts of papers to resolve disagreements. The quality of each included study was assessed with the QUADAS-2 evaluation scale.

RESULTS

Forty studies were included: two meta-analyses, 25 prospective controlled studies, five prospective uncontrolled studies, six retrospective controlled studies and two case reports. These biological tests assessed can be classified as: (i) proven to be effective at diagnosing LB and already in use (CXCL-13 for neuroborreliosis), but not enough to be standardized; (ii) not yet used routinely, requiring further clinical evaluation (CCL-19, OspA and interferon-α); (iii) uncertain LB diagnostic efficacy because of controversial results and/or poor methodological quality of studies evaluating them (lymphocyte transformation test, interferon-γ, ELISPOT); (iv) unacceptably low sensitivity and/or specificity (CD57⁺ natural killer cells and rapid diagnostic tests); and (v) possible only for research purposes (microscopy and xenodiagnoses).

DISCUSSION

QUADAS-2 quality assessment demonstrated high risk of bias in 25/40 studies and uncertainty regarding applicability for 32/40, showing that in addition to PCR and serology, several other LB diagnostic assays have been developed but their sensitivities and specificities are heterogeneous and/or under-evaluated or unassessed. More studies are warranted to evaluate their performance parameters. The development of active infection biomarkers would greatly advance LB diagnosis and monitoring.

Co-infection of bacteria and protozoan parasites in Ixodes ricinus nymphs collected in the Alsace region, France

Fifty nymphal Ixodes ricinus ticks collected in Alsace, France, identified by morphological criteria and using MALDI-TOF MS, were tested by PCR to detect tick-associated bacteria and protozoan parasites. Seventy percent (35/50) of ticks contained at least one microorganism; 26% (9/35) contained two or more species. Several human pathogens were identified including Borrelia burgdorferi s.s. (4%), Borrelia afzelii (2%), Borrelia garinii (2%), Borrelia valaisiana (4%), Borrelia miyamotoi (2%), Rickettsia helvetica (6%) and "Babesia venatorum" (2%). Bartonella spp. (10%) and a Wolbachia spp. (8%) were also detected. The most common co-infections involved Anaplasmataceae with Borrelia spp. (4%), Anaplasmataceae with Bartonella spp. (6%) and Anaplasmataceae with Rickettsia spp. (6%). Co-infection involving three different groups of bacteria was seen between bacteria of the family Anaplasmataceae, Borrelia spp. and Bartonella spp. (2%). Results highlight the panel of infectious agents carried by Ixodes ricinus. Co-infection suggests the possibility of transmission of more than one pathogen to human and animals during tick blood feeding.

Lyme borreliosis and other tick-borne diseases. Guidelines from the French scientific societies (II). Biological diagnosis, treatment, persistent symptoms after documented or suspected Lyme borreliosis

The serodiagnosis of Lyme borreliosis is based on a two-tier strategy: a screening test using an immunoenzymatic technique (ELISA), followed if positive by a confirmatory test with a western blot technique for its better specificity. Lyme serology has poor sensitivity (30-40%) for erythema migrans and should not be performed. The seroconversion occurs after approximately 6 weeks, with IgG detection (sensitivity and specificity both>90%). Serological follow-up is not recommended as therapeutic success is defined by clinical criteria only. For neuroborreliosis, it is recommended to simultaneously perform ELISA tests in samples of blood and cerebrospinal fluid to test for intrathecal synthesis of Lyme antibodies. Given the continuum between early localized and disseminated borreliosis, and the efficacy of doxycycline for the treatment of neuroborreliosis, doxycycline is preferred as the first-line regimen of erythema migrans (duration, 14 days; alternative: amoxicillin) and neuroborreliosis (duration, 14 days if early, 21 days if late; alternative: ceftriaxone). Treatment of articular manifestations of Lyme borreliosis is based on doxycycline, ceftriaxone, or amoxicillin for 28 days. Patients with persistent symptoms after appropriate treatment of Lyme borreliosis should not be prescribed repeated or prolonged antibacterial treatment. Some patients present with persistent and pleomorphic symptoms after documented or suspected Lyme borreliosis. Another condition is eventually diagnosed in 80% of them.

Epidemiology of Lyme borreliosis through two surveillance systems: the national Sentinelles GP network and the national hospital discharge database, France, 2005 to 2016

BACKGROUND

Lyme borreliosis (LB) is the most frequent vector-borne disease in France. Since 2009, surveillance of LB is conducted by a sentinel network of general practitioners (GPs). This system, in conjunction with the national hospitalisation database was used to estimate the incidence and describe the characteristics of LB in France.

AIM

To describe the estimated incidence and trends in GP consultations and hospital admissions for LB in France and identify risk groups and high-incidence regions.

RESULTS

From 2011 to 2016, the mean yearly incidence rate of LB cases was 53 per 100,000 inhabitants (95% CI: 41-65) ranging from 41 in 2011 to 84 per 100 000 in 2016. A mean of 799 cases per year were hospitalised with LB associated diagnoses 2005-16. The hospitalisation incidence rate (HIR) ranged from 1.1 cases per 100,000 inhabitants in 2005 to 1.5 in 2011 with no statistically significant trend. We observed seasonality with a peak during the summer, important inter-regional variations and a bimodal age distribution in LB incidence and HIR with higher incidence between 5 and 9 year olds and those aged 60 years. Erythema migrans affected 633/667 (95%) of the patients at primary care level. Among hospitalised cases, the most common manifestation was neuroborreliosis 4,906/9,594 (51%).

CONCLUSION

Public health strategies should focus on high-incidence age groups and regions during the months with the highest incidences and should emphasise prevention measures such as regular tick checks after exposure and prompt removal to avoid infection.

Characteristics and clinical outcomes after treatment of a national cohort of PCR-positive Lyme arthritis

OBJECTIVES

To describe the clinical and microbiological characteristics and outcomes after antibiotic treatment of a national cohort of patients with Lyme arthritis confirmed by PCR testing on synovial fluid and by serology, when available.

METHODS

Using the French National Reference Center for Borrelia database, patients with a positive PCR on synovial fluid for Borrelia were identified. Patient clinical and biological characteristics were reviewed from patient records. Long-term outcomes after treatment were studied through a questionnaire and with follow-up data.

RESULTS

Among 357 synovial fluid testing by PCR between 2010 and 2016, 37 (10.4%) were positive for Borrelia. Patients' median age was 36 years (range 6-78) with 61% of men and 28% patients under 18. The presentation was monoarticular in 92% and the knee was involved in 97%. Contrary to the Borrelia species repartition in European ticks, B. burgdorferi sensu stricto was the most prevalent species found in synovial fluid (54%) followed by B. azfelii (29%) and B. garinii (17%). Antibiotic treatments were mainly composed of doxycycline (n = 24), ceftriaxone (n = 10) and amoxicillin (n = 6), for a median duration of 4 weeks (range 3-12). Despite a properly conducted treatment, 34% of patients (n = 12) developed persistent synovitis for at least 2 months (median duration 3 months, range 2-16). Among those, 3 developed systemic inflammatory oligo- or polyarthritis in previously unaffected joints with no signs of persistent infection (repeated PCR testing negative), which mandated Disease-Modifying Antirheumatic Drugs (DMARD) introduction, leading to remission.

CONCLUSION

In France and contrary to ticks ecology, Lyme arthritis is mainly caused by B. burgdorferi sensu stricto. Despite proper antibiotic therapy, roughly one third of patients may present persistent inflammatory synovitis and a small proportion may develop systemic arthritis. In such cases, complete remission can be reached using DMARD.

A new hot spot for tick-borne encephalitis (TBE): A marked increase of TBE cases in France in 2016

OBJECTIVES

Tick-borne encephalitis virus (TBEV) is a zoonotic agent causing severe encephalitis. In 2016, in Northeastern France, we faced a TBEV infection increase, leading to a warning from the Regional Health Agency. Here, we report the confirmed TBE cases diagnosed between January 2013 and December 2016, with particular emphasis on the year 2016.

METHODS

A total of 1643 blood and cerebrospinal fluid (CSF) samples from everywhere in France, corresponding to 1460 patients, were prospectively tested for anti-TBEV-specific IgM and IgG antibodies by ELISA. Additional 39 blood and CSF samples from patients with suspected Lyme neuroborreliosis were retrospectively investigated.

RESULTS

The TBEV seropositivity rate was estimated to 5.89% and 54 patients were diagnosed as TBE-confirmed cases. A significant increase in TBE cases was observed during the year 2016 with 29 confirmed cases, instead of a mean of eight cases during the three previous years (p=0.0006). Six imported cases and 48 autochthonous cases, located in the Alsace region (n=43) and in the Alpine region (n=5) were reported. Forty-six patients experienced neurological impairment. Nine patients showed an incomplete recovery at last follow-up (from 15days to eight months post-infection). TBE diagnosis was performed earlier for patients taken in charge in the Alsace region than those hospitalized elsewhere in France (p=0.0087). Among the 39 patients with suspected Lyme neuroborreliosis retrospectively investigated, one showed a TBEV recent infection.

CONCLUSION

The TBE increase that occurred in France in 2016 highlights the need to improve our knowledge about the true burden of TBEV infection and subsequent long-term outcomes.

Assessment of MALDI-TOF MS biotyping for Borrelia burgdorferi sl detection in Ixodes ricinus

Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) has been demonstrated to be useful for tick identification at the species level. More recently, this tool has been successfully applied for the detection of bacterial pathogens directly in tick vectors. The present work has assessed the detection of Borrelia burgdorferi sensu lato in Ixodes ricinus tick vector by MALDI-TOF MS. To this aim, experimental infection model of I. ricinus ticks by B. afzelii was carried out and specimens collected in the field were also included in the study. Borrelia infectious status of I. ricinus ticks was molecularly controlled using half-idiosome to classify specimens. Among the 39 ticks engorged on infected mice, 14 were confirmed to be infected by B. afzelii. For field collection, 14.8% (n = 12/81) I. ricinus ticks were validated molecularly as infected by B. burgdorferi sl. To determine the body part allowing the detection of MS protein profile changes between non-infected and B. afzelii infected specimens, ticks were dissected in three compartments (i.e. 4 legs, capitulum and half-idiosome) prior to MS analysis. Highly reproducible MS spectra were obtained for I. ricinus ticks according to the compartment tested and their infectious status. However, no MS profile change was found when paired body part comparison between non-infected and B. afzelii infected specimens was made. Statistical analyses did not succeed to discover, per body part, specific MS peaks distinguishing Borrelia-infected from non-infected ticks whatever their origins, laboratory reared or field collected. Despite the unsuccessful of MALDI-TOF MS to classify tick specimens according to their B. afzelii infectious status, this proteomic tool remains a promising method for rapid, economic and accurate identification of tick species. Moreover, the singularity of MS spectra between legs and half-idiosome of I. ricinus could be used to reinforce this proteomic identification by submission of both these compartments to MS.

To test or not to test? Laboratory support for the diagnosis of Lyme borreliosis: a position paper of ESGBOR, the ESCMID study group for Lyme borreliosis

BACKGROUND

Lyme borreliosis (LB) is a tick-borne infection caused by Borrelia burgdorferi sensu lato. The most frequent clinical manifestations are erythema migrans and Lyme neuroborreliosis. Currently, a large volume of diagnostic testing for LB is reported, whereas the incidence of clinically relevant disease manifestations is low. This indicates overuse of diagnostic testing for LB with implications for patient care and cost-effective health management.

AIM

The recommendations provided in this review are intended to support both the clinical diagnosis and initiatives for a more rational use of laboratory testing in patients with clinically suspected LB.

SOURCES

This is a narrative review combining various aspects of the clinical and laboratory diagnosis with an educational purpose. The literature search was based on existing systematic reviews, national and international guidelines and supplemented with specific citations.

IMPLICATIONS

The main recommendations according to current European case definitions for LB are as follows. Typical erythema migrans should be diagnosed clinically and does not require laboratory testing. The diagnosis of Lyme neuroborreliosis requires laboratory investigation of the spinal fluid including intrathecal antibody production, and the remaining disease manifestations require testing for serum antibodies to B. burgdorferi. Testing individuals with non-specific subjective symptoms is not recommended, because of a low positive predictive value.

Seroprevalence of seven pathogens transmitted by the Ixodes ricinus tick in forestry workers in France

In order to assess the level of occupational exposure to the main pathogens transmitted by the Ixodes ricinus tick, a seroprevalence study was performed on serum samples collected in 2003 from 2975 forestry workers of northeastern France. The global seroprevalence estimated for the seven pathogens studied was 14.1% (419/2975) for Borrelia burgdorferi sl, 5.7% (164/2908) for Francisella tularensis, 2.3% (68/2941) for tick-borne encephalitis virus, 1.7% (50/2908) for Anaplasma phagocytophilum and 1.7% (48/2908) for Bartonella henselae. The seroprevalences of Babesia divergens and Babesia microti studied in a subgroup of participants seropositive for at least one of these latter pathogens were 0.1% (1/810) and 2.5% (20/810), respectively. Borrelia burgdorferi sl seroprevalence was significantly higher in Alsace and Lorraine and F. tularensis seroprevalence was significantly higher in Champagne-Ardenne and Franche-Comté. The results of this survey also suggest low rates of transmission of Bartonella henselae and F. tularensis by ticks and a different west/east distribution of Babesia species in France. The frequency and potential severity of these diseases justify continued promotion of methods of prevention of I. ricinus bites.

The diagnostic accuracy of serological tests for Lyme borreliosis in Europe: a systematic review and meta-analysis

Background

Interpretation of serological assays in Lyme borreliosis requires an understanding of the clinical indications and the limitations of the currently available tests. We therefore systematically reviewed the accuracy of serological tests for the diagnosis of Lyme borreliosis in Europe.

Methods

We searched EMBASE en MEDLINE and contacted experts. Studies evaluating the diagnostic accuracy of serological assays for Lyme borreliosis in Europe were eligible. Study selection and data-extraction were done by two authors independently. We assessed study quality using the QUADAS-2 checklist. We used a hierarchical summary ROC meta-regression method for the meta-analyses. Potential sources of heterogeneity were test-type, commercial or in-house, Ig-type, antigen type and study quality. These were added as covariates to the model, to assess their effect on test accuracy.

Results

Seventy-eight studies evaluating an Enzyme-Linked ImmunoSorbent assay (ELISA) or an immunoblot assay against a reference standard of clinical criteria were included. None of the studies had low risk of bias for all QUADAS-2 domains. Sensitivity was highly heterogeneous, with summary estimates: erythema migrans 50 % (95 % CI 40 % to 61 %); neuroborreliosis 77 % (95 % CI 67 % to 85 %); acrodermatitis chronica atrophicans 97 % (95 % CI 94 % to 99 %); unspecified Lyme borreliosis 73 % (95 % CI 53 % to 87 %). Specificity was around 95 % in studies with healthy controls, but around 80 % in cross-sectional studies. Two-tiered algorithms or antibody indices did not outperform single test approaches.

Conclusions

The observed heterogeneity and risk of bias complicate the extrapolation of our results to clinical practice. The usefulness of the serological tests for Lyme disease depends on the pre-test probability and subsequent predictive values in the setting where the tests are being used. Future diagnostic accuracy studies should be prospectively planned cross-sectional studies, done in settings where the test will be used in practice.

Incidence and hospitalisation rates of Lyme borreliosis, France, 2004 to 2012

Binary file ES_Abstracts_Final_ECDC.txt matches

Evolving epidemiology and antimicrobial resistance in spontaneous bacterial peritonitis: a two-year observational study

BACKGROUND

Current recommendations for empirical antimicrobial therapy in spontaneous bacterial peritonitis (SBP) are based on quite old trials. Since microbial epidemiology and the management of patients have changed, whether these recommendations are still appropriate must be confirmed.

METHODS

An observational study that exhaustively collected the clinical and biological data associated with positive ascitic fluid cultures was conducted in four French university hospitals in 2010-2011.

RESULTS

Two hundred and sixty-eight documented positive cultures were observed in 190 cirrhotic patients (median age 61.5 years, 58.5% Child score C). Of these, 57 were classified as confirmed SBP and 140 as confirmed bacterascites. The predominant flora was Gram-positive cocci, whatever the situation (SBP, bacterascites, nosocomial/health-care related or not). Enteroccocci (27.7% E. faecium) were isolated in 24% of the episodes, and in 48% from patients receiving quinolone prophylaxis. E. coli were susceptible to amoxicillin-clavulanate and to third-generation cephalosporins in 62.5% and 89.5% of cases, respectively. No single antibiotic allowed antimicrobial coverage of more than 60%. Only combinations such as amoxicillin + third-generation cephalosporin or cotrimoxazole allowed coverage close to 75-80% in non-nosocomial episodes. Combinations based on broader spectrum antibiotics should be considered for empirical therapy of nosocomial infections.

CONCLUSIONS

Our study confirmed the changing spectrum of pathogens in SBP and bacterascites, and the need for more complex antibiotic strategies than those previously recommended. Our findings also underline the need for new clinical trials conducted in the current epidemiological context.

In vitro activity of daptomycin against Enterococcus faecalis under various conditions of growth-phases, inoculum and pH

Enterococcus faecalis (E. faecalis) has become a major leading cause of nosocomial endocarditis. Treatment of such infections remains problematic and new therapeutic options are needed. Nine E. faecalis strains were tested: six obtained from patients presenting endocarditis, one with isolated bacteremia, and two reference strains. Antibiotics included daptomycin, alone or in combination, linezolid, tigecycline, rifampicin, gentamicin, teicoplanin, ceftriaxone and amoxicillin. Time-kill studies included colony counts at 1, 4 and 24 h of incubation. Significant bactericidal activity was defined as a decrease of ≥3log₁₀CFU/ml after 24 h of incubation. Antibiotics were tested at a low (10⁶ CFU/ml) and high (10⁹ CFU/ml) inoculum, against exponential- and stationary-phase bacteria. We also performed time kill studies of chemically growth arrested E. faecalis. Various pH conditions were used during the tests. In exponential growth phase and with a low inoculum, daptomycin alone at 60 µg/ml and the combination amoxicillin-gentamicin both achieved a 4-log₁₀ reduction in one hour on all strains. In exponential growth phase with a high inoculum, daptomycin alone was bactericidal at a concentration of 120 µg/ml. All the combinations tested with this drug were indifferent. In stationary phase with a high inoculum daptomycin remained bactericidal but exhibited a pH dependent activity and slower kill rates. All combinations that did not include daptomycin were not bactericidal in conditions of high inoculum, whatever the growth phase. The results indicate that daptomycin is the only antibiotic that may be able of overcoming the effects of growth phase and high inoculum.