Prospective study of serologic tests for lyme disease

Evaluation of Disease Causality of Rare Ixodes ricinus-Borne Infections in Europe

In Europe, Ixodes ricinus ticks transmit pathogens such as Borrelia burgdorferi sensu lato and tick-borne encephalitis virus (TBEV). In addition, there is evidence for transmission to humans from I. ricinus of Anaplasma phagocytophilum, Babesia divergens, Babesia microti, Babesia venatorum, Borrelia miyamotoi, Neoehrlichia mikurensis, Rickettsia helvetica and Rickettsia monacensis. However, whether infection with these potential tick-borne pathogens results in human disease has not been fully demonstrated for all of these tick-borne microorganisms. To evaluate the available evidence for a causative relation between infection and disease, the current study analyses European case reports published from 2008 to 2018, supplemented with information derived from epidemiological and experimental studies. The evidence for human disease causality in Europe found in this review appeared to be strongest for A. phagocytophilum and B. divergens. Nonetheless, some knowledge gaps still exist. Importantly, comprehensive evidence for pathogenicity is lacking for the remaining tick-borne microorganisms. Such evidence could be gathered best through prospective studies, for example, studies enrolling patients with a fever after a tick bite, the development of specific new serological tools, isolation of these microorganisms from ticks and patients and propagation in vitro, and through experimental studies.

Evaluation of Patient IgM and IgG Reactivity Against Multiple Antigens for Improvement of Serodiagnostic Testing for Early Lyme Disease

Serologic testing is the standard for laboratory diagnosis and confirmation of Lyme disease. Serodiagnostic assays to detect antibodies against Borrelia burgdorferi, the agent of Lyme borreliosis, are used for detection of infection. However, serologic testing within the first month of infection is less sensitive as patients' antibody responses continue to develop. Previously, we screened several B. burgdorferi in vivo expressed antigens for candidates that elicit early antibody responses in patients with Stage 1 and 2 Lyme disease. We evaluated patient IgM seroreactivity against 6 antigens and found an increase in sensitivity without compromising specificity when compared to current IgM second-tier immunoblot scoring. In this study, we continued the evaluation using a multi-antigen panel to measure IgM plus IgG seroreactivity in these early Lyme disease patients' serum samples. Using two statistical methods for calculating positivity cutoff values, sensitivity was 70 and 84-87%, for early acute and early convalescent Lyme disease patients, respectively. Specificity was 98-100% for healthy non-endemic control patients, and 96-100% for healthy endemic controls depending on the statistical analysis. We conclude that improved serologic testing for early Lyme disease may be achieved by the addition of multiple borrelial antigens that elicit IgM and IgG antibodies early in infection.

Is It Possible to Make a Correct Diagnosis of Lyme Disease on Symptoms Alone? Review of Key Issues and Public Health Implications

There is much confusion and misinformation about the diagnosis of Lyme disease, as well as its treatment. This review explains why one cannot make a correct diagnosis of Lyme disease based on symptoms alone. It also provides evidence to support the validity of two-tier testing for the laboratory diagnosis of Lyme disease. The public health consequences of failing to consider these issues are discussed.

Evaluation of the Modified Two-Tiered Testing Method for Diagnosis of Lyme Disease in Children

Conventional two-tiered testing (CTTT) for Lyme disease includes a first-tier enzyme immunoassay (EIA) followed by a supplemental immunoblot, and modified two-tiered testing (MTTT) relies on two different sequential EIAs without the inclusion of an immunoblot. MTTT has shown promising results as an alternative strategy for the diagnosis of Lyme disease in adults but has not yet been evaluated in children. We performed a cross-sectional study of children and adolescents ≤21 years of age undergoing clinical investigation for suspected Lyme disease. Serum specimens were analyzed with both a whole-cell sonicate (WCS) and a C6 EIA, with a supplemental immunoblot if either EIA was positive or equivocal. We compared CTTT (WCS EIA followed by supplemental immunoblot) to MTTT (WCS EIA followed by C6 EIA) using McNemar's test to evaluate for agreement beyond chance alone. We then used a kappa statistic to measure level of the agreement between testing strategies. We included 1,066 serum specimens, of which 156 (14.6%) had a positive CTTT and 165 (15.5%) had a positive MTTT. There were no significant differences between MTTT and CTTT (P = 0.16). Although the overall agreement between MTTT and CTTT was high (kappa, 0.88; 95% confidence interval, 0.84 to 0.92), 33 children had discordant test results. In a cohort of children and adolescents undergoing investigation for suspected Lyme disease, CTTT and MTTT results agreed in most cases. Since immunoblots are time-consuming, laborious, and challenging to interpret, MTTT provides a promising alternate Lyme disease testing strategy for children.

Proposed Lyme Disease Guidelines and Psychiatric Illnesses

The Infectious Disease Society of America, American Academy of Neurology, and American Academy of Rheumatology jointly proposed Lyme disease guidelines. Four areas most relevant to psychiatry were reviewed—the disclaimer, laboratory testing, and adult and pediatric psychiatric sections. The disclaimer and the manner in which these guidelines are implemented are insufficient to remove the authors and sponsoring organizations from liability for harm caused by these guidelines. The guidelines and supporting citations place improper credibility upon surveillance case definition rather than clinical diagnosis criteria. The guidelines fail to address the clear causal association between Lyme disease and psychiatric illnesses, suicide, violence, developmental disabilities and substance abuse despite significant supporting evidence. If these guidelines are published without very major revisions, and if the sponsoring medical societies attempt to enforce these guidelines as a standard of care, it will directly contribute to increasing a national and global epidemic of psychiatric illnesses, suicide, violence, substance abuse and developmental disabilities and the associated economic and non-economic societal burdens. The guideline flaws could be improved with a more appropriate disclaimer, an evidence-based rather than an evidence-biased approach, more accurate diagnostic criteria, and recognition of the direct and serious causal association between Lyme disease and psychiatric illnesses.

Incidence of Lyme disease in the UK: a population-based cohort study

OBJECTIVES

The purpose of this study was to estimate the annual incidence of Lyme disease (LD) in the UK.

DESIGN

This was a retrospective descriptive cohort study.

SETTING

Study data were extracted from the Clinical Practice Research Datalink (CPRD), a primary care database covering about 8% of the population in the UK in 658 primary care practices.

PARTICIPANTS

Cohort of 8.4 million individuals registered with general practitioners with 52.4 million person-years of observation between 1 January 2001 and 31 December 2012.

PRIMARY AND SECONDARY OUTCOME MEASURES

LD was identified from recorded medical codes, notes indicating LD, laboratory tests and use of specific antibiotics. Annual incidence rates and the estimated total number of LD cases were calculated separately for each UK region.

RESULTS

The number of cases of LD increased rapidly over the years 2001 to 2012, leading to an estimated incidence rate of 12.1 (95% CI 11.1 to 13.2) per 100 000 individuals per year and a UK total of 7738 LD cases in 2012. LD was detected in every UK region with highest incidence rates and largest number of cases in Scotland followed by South West and South England. If the number of cases has continued to rise since the end of the study period, then the number in the UK in 2019 could be over 8000. : Conclusions : The incidence of LD is about threefold higher than previously estimated, and people are at risk throughout the UK. These results should lead to increased awareness of the need for preventive measures.

TRIAL REGISTRATION NUMBER

This study was approved by the Independent Scientific Advisory Committee for CPRD research (Protocol number 13_210R).

Oral Management for Pediatric Lyme Meningitis

BACKGROUND

Guidelines for pediatric Lyme meningitis recommend treatment with parenteral therapy [1, 2]. Adult studies suggest that Lyme meningitis can be successfully treated with oral therapy. Our objective was to evaluate the clinical response, side effects and outcome of oral therapy for Lyme meningitis in the pediatric population compared with parenteral therapy in an area endemic for Lyme disease.

METHODS

We conducted a case series chart review from January 2012 to May 2017 of pediatrics patient diagnosed and treated for Lyme meningitis. We recorded clinical presentation, laboratory values, antimicrobial therapy and follow up after therapy to compare the efficacy of oral versus parenteral route of therapy.

RESULTS

We identified 38 patients diagnosed with Lyme meningitis. Thirty-two patients were discharge with exclusively oral therapy with: doxycycline and amoxicillin. We had only 2 patients developed potential adverse effects from oral doxycycline therapy. All patients treated with oral antibiotics had resolution of symptoms on follow up appointments.

CONCLUSIONS

Oral therapy for Lyme meningitis yields no serious adverse events, was well tolerated and showed resolution of symptoms.

Investigation of the performance of serological assays used for Lyme disease testing in Australia

Spirochaetes of the Borrelia burgdorferi sensu lato complex, which includes those that cause Lyme disease, have not been identified in Australia. Nevertheless, Australian patients exist, some of whom have not left the country, who have symptoms consistent with so-called “chronic Lyme disease”. Blood specimens from these individuals may be tested in Australian laboratories and in specialist laboratories outside Australia and sometimes conflicting results are obtained. Such discrepancies cause the patients to question the results from the Australian laboratories and seek assistance from the Australian Government in clarifying why the discrepancies occur. The aim of this study was to determine the level of agreement in results between commonly used B. burgdorferi serology assays in specimens of known status, and between results reported by different laboratories when they use the same serology assay. Five immunoassays and five immunoblots used in Australia and elsewhere were examined for the detection of IgG antibodies to Borrelia burgdorferi sensu lato. Predominantly, archived specimens previously tested for Lyme disease were used for the study and included 639 contributed by seven clinical laboratories located either in Australia or in areas endemic for Lyme disease. Also included were 308 prospectively collected Australian blood donor specimens. All clinical specimens were tested in all 10 assays whereas blood donor specimens were tested in all immunoassays and a subset was tested on immunoblots. With the exception of one immunoblot, the results between the assays agreed with each other in a known positive specimen population ≥ 77% of the time and in a known negative population, 88% of the time or greater. The test results obtained during the study were different from the participating laboratory’s less than 2% of the time when the same assay was used. These findings suggest that discordance in results between laboratories is more likely due to variation in algorithms or in the use of assays with different sensitivities or specificities rather than conflicting results being reported from the same assay in different laboratories. In the known negative population, specificities of the immunoassays ranged between 87.7% and 99.7%. In Australia’s low prevalence population, this would translate to a positive predictive value of < 4%.

A review on the occurrence of companion vector-borne diseases in pet animals in Latin America

Companion vector-borne diseases (CVBDs) are an important threat for pet life, but may also have an impact on human health, due to their often zoonotic character. The importance and awareness of CVBDs continuously increased during the last years. However, information on their occurrence is often limited in several parts of the world, which are often especially affected. Latin America (LATAM), a region with large biodiversity, is one of these regions, where information on CVBDs for pet owners, veterinarians, medical doctors and health workers is often obsolete, limited or non-existent. In the present review, a comprehensive literature search for CVBDs in companion animals (dogs and cats) was performed for several countries in Central America (Belize, Caribbean Islands, Costa Rica, Cuba, Dominican Republic, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Puerto Rico) as well as in South America (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, French Guiana, Guyana (British Guyana), Paraguay, Peru, Suriname, Uruguay, Venezuela) regarding the occurrence of the following parasitic and bacterial diseases: babesiosis, heartworm disease, subcutaneous dirofilariosis, hepatozoonosis, leishmaniosis, trypanosomosis, anaplasmosis, bartonellosis, borreliosis, ehrlichiosis, mycoplasmosis and rickettsiosis. An overview on the specific diseases, followed by a short summary on their occurrence per country is given. Additionally, a tabular listing on positive or non-reported occurrence is presented. None of the countries is completely free from CVBDs. The data presented in the review confirm a wide distribution of the CVBDs in focus in LATAM. This wide occurrence and the fact that most of the CVBDs can have a quite severe clinical outcome and their diagnostic as well as therapeutic options in the region are often difficult to access and to afford, demands a strong call for the prevention of pathogen transmission by the use of ectoparasiticidal and anti-feeding products as well as by performing behavioural changes.

A Next-Generation Sequencing-Based Molecular Approach to Characterize a Tick Vector in Lyme Disease

Next-generation sequencing approaches have revolutionized genomic medicine and enabled rapid diagnosis for several diseases. These approaches are widely used for pathogen detection in several infectious diseases. Lyme disease is a tick-borne infectious disease, which affects multiple organs. The causative organism is a spirochete, Borrelia burgdorferi, which is transmitted by ticks. Lyme disease can be treated easily if detected early, but its diagnosis is often delayed or is incorrect leading to a chronic debilitating condition. Current confirmatory diagnostic tests for Lyme disease rely on detection of antigens derived from B. burgdorferi, which are prone to both false positives and false negatives. Instead of focusing only on the human host for the diagnosis of Lyme disease, one could also attempt to identify the vector (tick) and the causative organism carried by the tick. Since all ticks do not transmit Lyme disease, it can be informative to accurately identify the tick from the site of bite, which is often observed by the patient and discarded. However, identifying ticks based on morphology alone requires a trained operator and can still be incorrect. Thus, we decided to take a molecular approach by sequencing DNA and RNA from a tick collected from an individual bitten by the tick. Using next-generation sequencing, we confirmed the identity of the tick as a dog tick, Dermacentor variabilis, and did not identify any pathogenic bacterial sequences, including Borrelia species. Despite the limited availability of nucleotide sequences for many types of ticks, our approach correctly identified the tick species. This proof-of-principle study demonstrates the potential of next-generation sequencing in the diagnosis of tick-borne infections, which can also be extended to other zoonotic diseases.

A minority of children diagnosed with Lyme disease recall a preceding tick bite

Of 1770 children undergoing emergency department evaluation for Lyme disease, 362 (20.5%) children had Lyme disease. Of those with an available tick bite history, only a minority of those with Lyme disease had a recognized tick bite (60/325; 18.5%, 95% confidence interval 14.6-23.0%). Lack of a tick bite history does not reliably exclude Lyme disease.

Lyme borreliosis-from tick bite to diagnosis and treatment

Lyme borreliosis is caused by certain genospecies of the Borrelia burgdorferi sensu lato complex, which are transmitted by hard ticks of the genus Ixodes. The most common clinical manifestation is erythema migrans, an expanding skin redness that usually develops at the site of a tick bite and eventually resolves even without antibiotic treatment. The infecting pathogens can spread to other tissues and organs, resulting in manifestations that can involve the nervous system, joints, heart and skin. Fatal outcome is extremely rare and is due to severe heart involvement; fetal involvement is not reliably ascertained. Laboratory support-mainly by serology-is essential for diagnosis, except in the case of typical erythema migrans. Treatment is usually with antibiotics for 2 to 4 weeks; most patients recover uneventfully. There is no convincing evidence for antibiotic treatment longer than 4 weeks and there is no reliable evidence for survival of borreliae in adequately treated patients. European Lyme borreliosis is a frequent disease with increasing incidence. However, numerous scientifically questionable ideas on its clinical presentation, diagnosis and treatment may confuse physicians and lay people. Since diagnosis of Lyme borreliosis should be based on appropriate clinical signs, solid knowledge of clinical manifestations is essential.

Under-Detection of Lyme Disease in Canada

Lyme disease arises from infection with pathogenic Borrelia species. In Canada, current case definition for confirmed Lyme disease requires serological confirmation by both a positive first tier ELISA and confirmatory second tier immunoblot (western blot). For surveillance and research initiatives, this requirement is intentionally conservative to exclude false positive results. Consequently, this approach is prone to false negative results that lead to underestimation of the number of people with Lyme disease. The province of New Brunswick (NB), Canada, can be used to quantify under-detection of the disease as three independent data sets are available to generate an estimate of the true human disease prevalence and incidence. First, detailed human disease incidence is available for the US states and counties bordering Canada, which can be compared with Canadian disease incidence. Second, published national serology results and well-described sensitivity and specificity values for these tests are available and deductive reasoning can be used to query for discrepancies. Third, high-density tick and canine surveillance data are available for the province, which can be used to predict expected human Lyme prevalence. Comparison of cross-border disease incidence suggests a minimum of 10.2 to 28-fold under-detection of Lyme disease (3.6% to 9.8% cases detected). Analysis of serological testing predicts the surveillance criteria generate 10.4-fold under-diagnosis (9.6% cases detected) in New Brunswick for 2014 due to serology alone. Calculation of expected human Lyme disease cases based on tick and canine infections in New Brunswick indicates a minimum of 12.1 to 58.2-fold underestimation (1.7% to 8.3% cases detected). All of these considerations apply generally across the country and strongly suggest that public health information is significantly under-detecting and under-reporting human Lyme cases across Canada. Causes of the discrepancies between reported cases and predicted actual cases may include undetected genetic diversity of Borrelia in Canada leading to failed serological detection of infection, failure to consider and initiate serological testing of patients, and failure to report clinically diagnosed acute cases. As these surveillance criteria are used to inform clinical and public health decisions, this under-detection will impact diagnosis and treatment of Canadian Lyme disease patients.

Correlation of Lyme Disease-Associated IgG4 Autoantibodies With Synovial Pathology in Antibiotic-Refractory Lyme Arthritis

OBJECTIVE

To determine whether IgG subclasses of Borrelia burgdorferi antibodies differ from those of 3 Lyme disease (LD)-associated autoantibodies.

METHODS

IgG antibody subclasses were determined by enzyme-linked immunosorbent assay in serum samples from 215 patients with features representative of each of the 3 stages of LD. Antibody and cytokine profiles were measured in matched serum and synovial fluid (SF) samples from patients with Lyme arthritis. Synovial tissue from patients with antibiotic-refractory arthritis was examined for histologic features, IgG subclasses of plasma cells, and messenger RNA (mRNA) subclass expression.

RESULTS

B burgdorferi antibodies were primarily of the IgG1 and IgG3 subclasses, and the levels increased as the infection progressed. In contrast, LD-associated autoantibodies were mainly of the IgG2 and IgG4 subclasses, and these responses were found primarily in patients with either antibiotic-refractory or antibiotic-responsive arthritis, particularly in SF. However, compared with the responsive group, the inflammatory milieu in SF in the refractory group was enriched for cytokines representative of innate, Th1, Th2, and Th17 responses. Synovial tissue in a subgroup of patients with refractory arthritis showed marked expression of mRNA for IgG4 antibodies and large numbers of IgG4-staining plasma cells. IgG4 autoantibodies in SF to each of the 3 LD-associated autoantigens correlated with the magnitude of obliterative microvascular lesions and fibrosis in the tissue.

CONCLUSION

Our findings indicate that the subclasses of IgG antibodies to B burgdorferi differ from those of LD-associated autoantibodies. Furthermore, the correlation of IgG4 autoantibodies with specific synovial pathology in the refractory group suggests a role for these autoantibodies, either protective or pathologic, in antibiotic-refractory Lyme arthritis.

Systematic Approach to the Diagnosis and Treatment of Lyme Carditis and High-Degree Atrioventricular Block

Lyme carditis (LC) is a manifestation of the early disseminated stage of Lyme disease and often presents as high-degree atrioventricular (AV) block. High-degree AV block in LC can be treated with antibiotics, usually resolving with a highly favorable prognosis, thus preventing the unnecessary implantation of permanent pacemakers. We present a systematic approach to the diagnosis and management of LC that implements the Suspicious Index in Lyme Carditis (SILC) risk stratification score.

Pilot Study of Immunoblots with Recombinant Borrelia burgdorferi Antigens for Laboratory Diagnosis of Lyme Disease

Accurate laboratory diagnosis of Lyme disease (Lyme borreliosis), caused by the spirochete Borrelia burgdorferi (BB), is difficult and yet important to prevent serious disease. The US Centers for Disease Control and Prevention (CDC) presently recommends a screening test for serum antibodies followed by confirmation with a more specific Western blot (WB) test to detect IgG and IgM antibodies against antigens in whole cell lysates of BB. Borrelia species related to BB cause tick-borne relapsing fever (TBRF). TBRF is increasingly recognized as a health problem in the US and occurs in areas where Lyme disease is prevalent. The two groups of Borrelia share related antigens. We have developed a modified WB procedure termed the Lyme immunoblots (IBs) using recombinant antigens from common strains and species of the BB sensu lato complex for serological diagnosis of Lyme disease. A reference collection of 178 sera from 26 patients with and 152 patients without Lyme disease were assessed by WB and IB in a blinded manner using either criteria for positive antibody reactions recommended by the CDC or criteria developed in-house. The sensitivity, specificity, positive and negative predictive values obtained with the reference sera suggest that the Lyme IB is superior to the Lyme WB for detection of specific antibodies in Lyme disease. The Lyme IB showed no significant reaction with rabbit antisera produced against two Borrelia species causing TBRF in the US, suggesting that the Lyme IB may be also useful for excluding TBRF.

Case report: persistently seronegative neuroborreliosis in an immunocompromised patient

Background

Infection with Borrelia burgdorferi sensu lato complex (B. b. sl) spirochetes can cause Lyme borreliosis, manifesting as localized infection (e.g. erythema migrans) or disseminated disease (e.g. Lyme neuroborreliosis). Generally, patients with disseminated Lyme borreliosis will produce an antibody response several weeks post-infection. So far, no case of neuroborreliosis has been described with persistently negative serology one month after infection.

Case presentation

We present a patient with a history of Mantle cell lymphoma and treatment with R-CHOP (rituximab, doxorubicine, vincristine, cyclofosfamide, prednisone), with a meningo-encephalitis, who was treated for a suspected lymphoma relapse. However, no malignant cells or other signs of malignancy were found, and microbial tests did not reveal any clues, including Borrelia serology. He did not recall being bitten by ticks, and a Borrelia PCR on CSF was negative. After spontaneous improvement of symptoms, he was discharged without definite diagnosis. Several weeks later, he was readmitted with a relapse of symptoms of meningo-encephalitis. This time however, a Borrelia PCR on CSF was positive, confirmed by two independent laboratories, and the patient received ceftriaxone upon which he partially recovered. Interestingly, during the diagnostic process of this exceptionally difficult case, a variety of different serological assays for Borrelia antibodies remained negative. Only P41 (flagellin) IgG was detected by blot and the Liaison IgG became equivocal 2 months after initial testing.

Conclusions

To the best of our knowledge this is the first case of neuroborreliosis that is seronegative on repeated sera and multiple test modalities. This unique case demonstrates the difficulty to diagnose neuroborreliosis in severely immunocompromised patients. In this case, a delay in diagnosis was caused by broad differential diagnosis, an absent known history of tick bites, negative serology and the low sensitivity of PCR on CSF. Therefore, awareness of the diagnostic limitations to detect Borrelia infection in this specific patient category is warranted.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3273-8) contains supplementary material, which is available to authorized users.

Revisiting the Lyme Disease Serodiagnostic Algorithm: the Momentum Gathers

Lyme disease is a tick-borne illness caused by Borreliella (Borrelia) burgdorferi, and it is the most common vector-borne disease in the United States, with an estimated incidence of 300,000 cases per year. The currently recommended approach for laboratory support of the diagnosis of Lyme disease is a standard two-tiered (STT) algorithm comprised of an enzyme-linked immunoassay (EIA) or immunofluorescence assay (IFA), followed by Western blotting (WB). The STT algorithm has low sensitivity in early infection, and there are drawbacks associated with the WB use in practice. Modified two-tiered (MTT) algorithms have been shown to improve the sensitivity of the testing in early disease while maintaining high specificity. In this issue of the Journal of Clinical Microbiology, A. Pegalajar-Jurado et al. (J Clin Microbiol 56:e01943-17, 2018, https://doi.org/10.1128/JCM.01943-17) report the results of their evaluation of the Liaison VlsE CLIA, the Captia B. burgdorferi IgG/IgM EIA, and the C6 B. burgdorferi (Lyme) EIA as MTT algorithms compared with results with the STT algorithm using the same tests as the first-tier test and the ViraStripe IgM and IgG WBs as the second-tier test. The results showed that all MTT algorithms had higher sensitivities than STT algorithms and were highly specific. These results showed that MTT approaches are a valid alternative to the currently recommended STT algorithm for serodiagnosis of Lyme disease, opening the door for the development of rapid diagnostics and point-of-care testing that can provide diagnostic information during the initial patient visit.

The host response as a tool for infectious disease diagnosis and management

INTRODUCTION

A century of advances in infectious disease diagnosis and treatment changed the face of medicine. However, challenges continue to develop including multi-drug resistance, globalization that increases pandemic risks, and high mortality from severe infections. These challenges can be mitigated through improved diagnostics, and over the past decade, there has been a particular focus on the host response. Since this article was originally published in 2015, there have been significant developments in the field of host response diagnostics, warranting this updated review. Areas Covered: This review begins by discussing developments in single biomarkers and pauci-analyte biomarker panels. It then delves into 'omics, an area where there has been truly exciting progress. Specifically, progress has been made in sepsis diagnosis and prognosis; differentiating viral, bacterial, and fungal pathogen classes; pre-symptomatic diagnosis; and understanding disease-specific diagnostic challenges in tuberculosis, Lyme disease, and Ebola. Expert Commentary: As 'omics have become faster, more precise, and less expensive, the door has been opened for academic, industry, and government efforts to develop host-based infectious disease classifiers. While there are still obstacles to overcome, the chasm separating these scientific advances from the patient's bedside is shrinking.

A Community Study of Borrelia burgdorferi Antibodies among Individuals with Prior Lyme Disease in Endemic Areas

The objective was to examine the prevalence of Borrelia antibodies among symptomatic individuals with recent and past Lyme disease in endemic communities using standard assays and novel assays employing next-generation antigenic substrates. Single- and two-tiered algorithms included different anti-Borrelia ELISAs and immunoblots. Antibody prevalence was examined in sera from 32 individuals with recent erythema migrans (EM), 335 individuals with persistent symptoms following treatment for Lyme disease (PTLS), and 41 community controls without a history of Lyme disease. Among convalescent EM cases, sensitivity was highest using the C6 ELISA (93.8%) compared to other single assays; specificity was 92.7% for the C6 ELISA vs. 85.4–97.6% for other assays. The two-tiered ELISA-EUROLINE IgG immunoblot combinations enhanced case detection substantially compared to the respective ELISA-IgG Western blot combinations (75.0% vs. 34.4%) despite similar specificity (95.1% vs. 97.6%, respectively). For PTLS cohorts, two-tier ELISA-IgG-blot positivity ranged from 10.1% to 47.4%, depending upon assay combination, time from initial infection, and clinical history. For controls, the two-tier positivity rate was 0–14.6% across assays. A two-tier algorithm of two-ELISA assays yielded a high positivity rate of 87.5% among convalescent EM cases with specificity of 92.7%. For convalescent EM, combinations of the C6 ELISA with a second-tier ELISA or line blot may provide useful alternatives to WB-based testing algorithms.

Development of a tick-borne pathogen QPCR panel for detection of Anaplasma, Ehrlichia, Rickettsia, and Lyme disease Borrelia in animals

Anaplasma spp., Ehrlichia spp., Rickettsia spp., and Lyme disease associated Borrelia spp. are the most common tick-borne pathogens reported to infect human beings worldwide and other animals, such as dogs and horses. In the present study, we developed a broad-coverage SYBR Green QPCR panel consisting of four individual assays for the detection and partial differentiation of the aforementioned pathogens. All assays were optimized to the same thermocycling condition and had a detection limit of 10 copies per reaction. The assays remained sensitive when used to test canine and equine blood DNA samples spiked with known amounts of synthetic DNA (gBlock) control template. The assays were specific, as evidenced by lack of cross reaction to non-target gBlock or other pathogens commonly tested in veterinary diagnostic labs. With appropriate Ct cutoff values for positive samples and negative controls and the melting temperature (TM) ranges established in the present study, the QPCR panel is suitable for accurate, convenient and rapid screening and confirmation of tick-borne pathogens in animals.

Efficient detection of symptomatic and asymptomatic patient samples for Babesia microti and Borrelia burgdorferi infection by multiplex qPCR

BACKGROUND

Tick-borne infections have been increasing steadily over the years, with co-infections with Borrelia burgdorferi and Babesia microti/divergens emerging as a serious health problem. B. burgdorferi is a spirochetal bacterium that causes Lyme disease while protozoan pathogens belonging to Babesia species are responsible for babesiosis. Currently used serological tests do not always detect acute Lyme disease or babesiosis, and fail to differentiate cured patients from those who get re-infected. This is a major problem for proper diagnosis particularly in regions endemic for tick-borne diseases. Microscopy based evaluation of babesiosis is confirmatory but is labor intensive and insensitive such that many asymptomatic patients remain undetected and donate blood resulting in transfusion transmitted babesiosis.

RESULTS

We conducted multiplex qPCR for simultaneous diagnosis of active Lyme disease and babesiosis in 192 blood samples collected from a region endemic for both diseases. We document qPCR results obtained from testing of each sample three times to detect infection with each pathogen separately or together. Results for Lyme disease by qPCR were also compared with serological tests currently used for Lyme disease when available. Considering at least two out of three test results for consistency, 18.2% of patients tested positive for Lyme disease, 18.7% for co-infection with B. burgdorferi and B. microti and 6.3% showed only babesiosis.

CONCLUSIONS

With an 80% sensitivity for detection of Lyme disease, and ability to detect co-infection with B. microti, multiplex qPCR can be employed for diagnosis of these diseases to start appropriate treatment in a timely manner.

Advances in Serodiagnostic Testing for Lyme Disease Are at Hand

The cause of Lyme disease, Borrelia burgdorferi, was discovered in 1983. A 2-tiered testing protocol was established for serodiagnosis in 1994, involving an enzyme immunoassay (EIA) or indirect fluorescence antibody, followed (if reactive) by immunoglobulin M and immunoglobulin G Western immunoblots. These assays were prepared from whole-cell cultured B. burgdorferi, lacking key in vivo expressed antigens and expressing antigens that can bind non-Borrelia antibodies. Additional drawbacks, particular to the Western immunoblot component, include low sensitivity in early infection, technical complexity, and subjective interpretation when scored by visual examination. Nevertheless, 2-tiered testing with immunoblotting remains the benchmark for evaluation of new methods or approaches. Next-generation serologic assays, prepared with recombinant proteins or synthetic peptides, and alternative testing protocols, can now overcome or circumvent many of these past drawbacks. This article describes next-generation serodiagnostic testing for Lyme disease, focusing on methods that are currently available or near-at-hand.

Occurrence of Lyme disease infection in a non-endemic area in Northern Italy

BACKGROUND

In Italy, the incidence of human tick-borne disease has increased over the last decades. Since 2015 a multidisciplinary group has been established in Sacco Hospital for the management of the patients affected by Lyme disease (LD). A retrospective evaluation (2015-2017) was performed for LD in non-endemic areas.

METHODS

Retrospective analysis of all 1000 samples for 800 patients screened for LD antibodies at the Sacco Hospital in 3 years (2015-2017). Clinical and epidemiological data were collected and compared with the serological results.

RESULTS

Among the 800 patients screened, 134 of them were diagnosed with borreliosis during 2015 (37 cases), 2016 (31 cases) and 2017 (66 cases). Localized LD was diagnosed 100 out of 134 cases (69%): in most of them (N.=63) erythema migrans has been documented; in 37 out of 100 it was not possible to detect it. In only three cases, patients complained of different clinical symptoms such as headache, arm and facial pain respectively. 23 out of 134 cases (16%) showed a persistence of serological positivity and symptoms with osteomuscular involvement and fatigue, despite the therapy (late LD). In that same study 11 out of 134 patients (7%) received a diagnosis of neuroborreliosis.

CONCLUSIONS

Our data reported a high percentage of LD infection (19%) in a non-endemic area. The definition of a Multidisciplinary Working Group and a clinical care pathway allowed a better clinical management of LD cases treated in Sacco Hospital, Milan.

Lyme Disease Testing in a High-Incidence State: Clinician Knowledge and Patterns

OBJECTIVES

Lyme disease (LD) incidence is increasing, but data suggest some clinicians are not fully aware of recommended procedures for ordering and interpreting diagnostic tests. The study objective was to assess clinicians' knowledge and practices regarding LD testing in a high-incidence region.

METHODS

We distributed surveys to 1,142 clinicians in the University of Vermont Medical Center region, of which 144 were completed (12.6% response rate). We also examined LD laboratory test results and logs of calls to laboratory customer service over a period of 2.5 years and 6 months, respectively.

RESULTS

Most clinicians demonstrated basic knowledge of diagnostic protocols, but many misinterpreted Western blot results. For example, 42.4% incorrectly interpreted a positive immunoglobulin M result as an overall positive test in a patient with longstanding symptoms. Many also reported receiving patient requests for unvalidated tests.

CONCLUSIONS

Additional education and modifications to LD test ordering and reporting systems would likely reduce errors and improve patient care.

Accuracy of Clinician Suspicion of Lyme Disease in the Emergency Department

BACKGROUND

To make initial management decisions, clinicians must estimate the probability of Lyme disease before diagnostic test results are available. Our objective was to examine the accuracy of clinician suspicion for Lyme disease in children undergoing evaluation for Lyme disease.

METHODS

We assembled a prospective cohort of children aged 1 to 21 years who were evaluated for Lyme disease at 1 of the 5 participating emergency departments. Treating physicians were asked to estimate the probability of Lyme disease (on a 10-point scale). We defined a Lyme disease case as a patient with an erythema migrans lesion or positive 2-tiered serology results in a patient with compatible symptoms. We calculated the area under the curve for the receiver operating curve as a measure of the ability of clinician suspicion to diagnose Lyme disease.

RESULTS

We enrolled 1021 children with a median age of 9 years (interquartile range, 5-13 years). Of these, 238 (23%) had Lyme disease. Clinician suspicion had a minimal ability to discriminate between children with and without Lyme disease: area under the curve, 0.75 (95% confidence interval, 0.71-0.79). Of the 554 children who the treating clinicians thought were unlikely to have Lyme disease (score 1-3), 65 (12%) had Lyme disease, and of the 127 children who the treating clinicians thought were very likely to have Lyme disease (score 8-10), 39 (31%) did not have Lyme disease.

CONCLUSIONS

Because clinician suspicion had only minimal accuracy for the diagnosis of Lyme disease, laboratory confirmation is required to avoid both under- and overdiagnosis.

Autoimmune Arthritides, Rheumatoid Arthritis, Psoriatic Arthritis, or Peripheral Spondyloarthritis Following Lyme Disease

OBJECTIVE

To describe systemic autoimmune joint diseases that develop following Lyme disease, and to compare their clinical features with those of Lyme arthritis (LA).

METHODS

We reviewed records of all adult patients referred to our LA clinic over a 13-year period, in whom we had diagnosed a systemic autoimmune joint disease following Lyme disease. For comparison, records of patients enrolled in our LA cohort over the most recent 2-year period were analyzed. Levels of IgG antibodies to Borrelia burgdorferi and to 3 Lyme disease-associated autoantigens were measured.

RESULTS

We identified 30 patients who had developed a new-onset systemic autoimmune joint disorder a median of 4 months after Lyme disease (usually manifested by erythema migrans [EM]). Fifteen had rheumatoid arthritis (RA), 13 had psoriatic arthritis (PsA), and 2 had peripheral spondyloarthritis (SpA). The 30 patients typically had polyarthritis, and those with PsA or SpA often had previous psoriasis, axial involvement, or enthesitis. In the comparison group of 43 patients with LA, the usual clinical picture was monoarticular knee arthritis, without prior EM. Most of the patients with systemic autoimmune joint disorders were positive for B burgdorferi IgG antibodies, as detected by enzyme-linked immunosorbent assay, but had significantly lower titers and lower frequencies of Lyme disease-associated autoantibodies than patients with LA. Prior to our evaluation, these patients had often received additional antibiotics for presumed LA, without benefit. We prescribed antiinflammatory agents, most commonly disease-modifying antirheumatic drugs, resulting in improvement.

CONCLUSION

Systemic autoimmune joint diseases (i.e., RA, PsA, SpA) may follow Lyme disease. Development of polyarthritis after antibiotic-treated EM, previous psoriasis, or low-titer B burgdorferi antibodies may provide insight into the correct diagnosis.

Evaluation of Modified 2-Tiered Serodiagnostic Testing Algorithms for Early Lyme Disease

Background

The conventional 2-tiered serologic testing protocol for Lyme disease (LD), an enzyme immunoassay (EIA) followed by immunoglobulin M and immunoglobulin G Western blots, performs well in late-stage LD but is insensitive in patients with erythema migrans (EM), the most common manifestation of the illness. Western blots are also complex, difficult to interpret, and relatively expensive. In an effort to improve test performance and simplify testing in early LD, we evaluated several modified 2-tiered testing (MTTT) protocols, which use 2 assays designed as first-tier tests sequentially, without the need of Western blots.

Methods

The MTTT protocols included (1) a whole-cell sonicate (WCS) EIA followed by a C6 EIA; (2) a WCS EIA followed by a VlsE chemiluminescence immunoassay (CLIA); and (3) a variable major protein-like sequence, expressed (VlsE) CLIA followed by a C6 EIA. Sensitivity was determined using serum from 55 patients with erythema migrans; specificity was determined using serum from 50 patients with other illnesses and 1227 healthy subjects.

Results

Sensitivity of the various MTTT protocols in patients with acute erythema migrans ranged from 36% (95% confidence interval [CI], 25%-50%) to 54% (95% CI, 42%-67%), compared with 25% (95% CI, 16%-38%) using the conventional protocol (P = .003-0.3). Among control subjects, the 3 MTTT protocols were similarly specific (99.3%-99.5%) compared with conventional 2-tiered testing (99.5% specificity; P = .6-1.0).

Conclusions

Although there were minor differences in sensitivity and specificity among MTTT protocols, each provides comparable or greater sensitivity in acute EM, and similar specificity compared with conventional 2-tiered testing, obviating the need for Western blots.

Infectious Diseases in Pregnancy

Many infectious diseases have the potential to complicate pregnancy. Some illnesses may only impact maternal health, but others can infect the fetus with possible devastating or long-term sequelae. In this chapter we aim to review common infectious diseases such as urinary tract infections and influenza as well as those that can cause major neonatal morbidity and mortality including TORCH infections. We will also discuss the challenges that pregnancy creates for the management of these infectious diseases as some antibiotics that would typically be used may not be safe for the developing fetus depending on the stage of pregnancy.

Topical azithromycin for the prevention of Lyme borreliosis: a randomised, placebo-controlled, phase 3 efficacy trial

BACKGROUND

Lyme borreliosis develops in 1-5% of individuals bitten by ticks, but with a diagnostic gap affecting up to 30% of patients, a broadly applicable pharmacological prevention strategy is needed. Topical azithromycin effectively eradicated Borrelia burgdorferi sensu lato from the skin in preclinical studies. We assessed its efficacy in human beings.

METHODS

In this randomised, double-blind, placebo-controlled, multicentre trial done in 28 study sites in Germany and Austria, adults were equally assigned to receive topical 10% azithromycin or placebo twice daily for 3 consecutive days, within 72 h of a tick bite being confirmed. Randomisation numbers, which were stratified by study site, were accessed in study centres via an interactive voice-response system, by pharmacists not involved in the study. The primary outcome was the number of treatment failures, defined as erythema migrans, seroconversion, or both, in participants who were seronegative at baseline, had no further tick bites during the study, and had serology results available at 8 weeks (intention-to-treat [ITT] population). This study is registered with EudraCT, number 2011-000117-39.

FINDINGS

Between July 7, 2011, and Dec 3, 2012, 1371 participants were randomly assigned to treatment, of whom 995 were included in the ITT population. The trial was stopped early because an improvement in the primary endpoint in the group receiving azithromycin was not reached. At 8 weeks, 11 (2%) of 505 in the azithromycin group and 11 (2%) of 490 in the placebo group had treatment failure (odds ratio 0·97, 95% CI 0·42-2·26, p=0·47). Topical azithromycin was well tolerated. Similar numbers of patients had adverse events in the two groups (175 [26%] of 505 vs 177 [26%] of 490, p=0·87), and most adverse events were mild.

INTERPRETATION

Topical azithromycin was well tolerated and had a good safety profile. Inclusion of asymptomatic seroconversion into the primary efficacy analysis led to no prevention effect with topical azithromycin. Adequately powered studies assessing only erythema migrans should be considered. A subgroup analysis in this study suggested that topical azithromycin reduces erythema migrans after bites of infected ticks.

FUNDING

Ixodes AG.

Lyme borreliosis

Lyme borreliosis is a tick-borne disease that predominantly occurs in temperate regions of the northern hemisphere and is primarily caused by the bacterium Borrelia burgdorferi in North America and Borrelia afzelii or Borrelia garinii in Europe and Asia. Infection usually begins with an expanding skin lesion, known as erythema migrans (referred to as stage 1), which, if untreated, can be followed by early disseminated infection, particularly neurological abnormalities (stage 2), and by late infection, especially arthritis in North America or acrodermatitis chronica atrophicans in Europe (stage 3). However, the disease can present with any of these manifestations. During infection, the bacteria migrate through the host tissues, adhere to certain cells and can evade immune clearance. Yet, these organisms are eventually killed by both innate and adaptive immune responses and most inflammatory manifestations of the infection resolve. Except for patients with erythema migrans, Lyme borreliosis is diagnosed based on a characteristic clinical constellation of signs and symptoms with serological confirmation of infection. All manifestations of the infection can usually be treated with appropriate antibiotic regimens, but the disease can be followed by post-infectious sequelae in some patients. Prevention of Lyme borreliosis primarily involves the avoidance of tick bites by personal protective measures.

Commercial test kits for detection of Lyme borreliosis: a meta-analysis of test accuracy

The clinical diagnosis of Lyme borreliosis can be supported by various test methodologies; test kits are available from many manufacturers. Literature searches were carried out to identify studies that reported characteristics of the test kits. Of 50 searched studies, 18 were included where the tests were commercially available and samples were proven to be positive using serology testing, evidence of an erythema migrans rash, and/or culture. Additional requirements were a test specificity of ≥85% and publication in the last 20 years. The weighted mean sensitivity for all tests and for all samples was 59.5%. Individual study means varied from 30.6% to 86.2%. Sensitivity for each test technology varied from 62.4% for Western blot kits, and 62.3% for enzyme-linked immunosorbent assay tests, to 53.9% for synthetic C6 peptide ELISA tests and 53.7% when the two-tier methodology was used. Test sensitivity increased as dissemination of the pathogen affected different organs; however, the absence of data on the time from infection to serological testing and the lack of standard definitions for “early” and “late” disease prevented analysis of test sensitivity versus time of infection. The lack of standardization of the definitions of disease stage and the possibility of retrospective selection bias prevented clear evaluation of test sensitivity by “stage”. The sensitivity for samples classified as acute disease was 35.4%, with a corresponding sensitivity of 64.5% for samples from patients defined as convalescent. Regression analysis demonstrated an improvement of 4% in test sensitivity over the 20-year study period. The studies did not provide data to indicate the sensitivity of tests used in a clinical setting since the effect of recent use of antibiotics or steroids or other factors affecting antibody response was not factored in. The tests were developed for only specific Borrelia species; sensitivities for other species could not be calculated.

Claims-Based Diagnostic Patterns of Patients Evaluated for Lyme Disease and Given Extended Antibiotic Therapy

BACKGROUND

A Lyme disease (LD) diagnosis can be far from straightforward, particularly if erythema migrans does not develop or is not noticed. Extended courses of antibiotics for LD are not recommended, but their use is increasing. We sought to elucidate the patient patterns toward a diagnosis of LD, hypothesizing that a subset of patients ultimately receiving extended courses antibiotics may be symptomatic for an extended period before the first LD diagnosis.

METHODS

Claims submitted to a nationwide U.S. health insurance plan in 14 high-prevalence states were grouped into standardized diagnostic categories. The patterns of diagnostic categories over time were compared between patients evaluated for LD and given standard antibiotic therapy (PLDSA) and patients evaluated for LD and given extended antibiotic therapy (PLDEA) in 2011-2012.

RESULTS

The incidence of PLDSA was 40.45 (N = 3207) and that of PLDEA was 7.57 (N = 600) per 100,000 insured over 2011-2012. 50.3% of PLDEA were diagnosed in the nonsummer months. Seven diagnostic categories were associated with PLDEA. From 180 days before the first LD diagnosis, the risks of having claims associated with back problems (odds ratio [OR], 2.1; confidence interval [95% CI], 1.4-2.9; p < 0.001) and connective tissue disease (OR, 1.6; 95% CI, 1.1-2.3; p < 0.01) complaints were higher among PLDEA. From 90 days before the diagnosis, malaise and fatigue (OR, 1.7; 95% CI, 1.1-2.6; p < 0.05), other nervous system disorders (OR, 2.0; 95% CI, 1.3-3.1; p < 0.01), and nontraumatic joint disorder (OR, 1.4; 95% CI, 1.0-2.0; p < 0.05) were more likely found among PLDEA than PLDSA. From 30 days before the diagnosis, the risk for mental health (OR 1.6; 95% CI, 1.1-2.0; p < 0.01) and headache (OR 1.5; 95% CI, 1.1-2.0; p < 0.05) among PLDEA was elevated.

CONCLUSIONS

Among patients evaluated for LD and ultimately receiving an extended course of antibiotics for LD, 15.8% of them were symptomatic and seeking care for several months before their first LD diagnosis.

Lyme Disease Diagnosis: Serology

Serology is the mainstay of confirmation of Lyme borreliosis; direct detection has limited application. Because standardized 2-tier testing (STTT) has been commonly used since the mid 1990s, standardization and performance have improved. STTT detection of early, localized infection is poor; that of late disease is good. The best indicator of stage 1 infection, erythema migrans, is presented in the majority of US cases and should prompt treatment without testing. Clinical and epidemiologic correlates should be carefully assessed before ordering STTT. STTT has great value in confirming extracutaneous infection. Recent developments promise to improve performance, particularly in early disease detection.

Evaluation of the C6 Lyme Enzyme Immunoassay for the Diagnosis of Lyme Disease in Children and Adolescents

BACKGROUND

The commercially-available C6 Lyme enzyme immunoassay (EIA) has been approved to replace the standard whole-cell sonicate EIA as a first-tier test for the diagnosis of Lyme disease and has been suggested as a stand-alone diagnostic. However, the C6 EIA has not been extensively studied in pediatric patients undergoing evaluation for Lyme disease.

METHODS

We collected discarded serum samples from children and adolescents (aged ≤21 years) undergoing conventional 2-tiered testing for Lyme disease at a single hospital-based clinical laboratory located in an area endemic for Lyme disease. We performed a C6 EIA on all collected specimens, followed by a supplemental immunoblot if the C6 EIA result was positive but the whole-cell sonicate EIA result was negative. We defined a case of Lyme disease as either a clinician-diagnosed erythema migrans lesion or a positive standard 2-tiered serologic result in a patient with symptoms compatible with Lyme disease. We then compared the performance of the C6 EIA alone and as a first-tier test followed by immunoblot, with that of standard 2-tiered serology for the diagnosis of Lyme disease.

RESULTS

Of the 944 specimens collected, 114 (12%) were from patients with Lyme disease. The C6 EIA alone had sensitivity similar to that of standard 2-tiered testing (79.8% vs 81.6% for standard 2-tiered testing; P = .71) with slightly lower specificity (94.2% vs 98.8% 2; P < .002). Addition of a supplemental immunoblot improved the specificity of the C6 EIA to 98.6%.

CONCLUSIONS

For children and adolescents undergoing evaluation for Lyme disease, the C6 EIA could guide initial clinical decision making, although a supplemental immunoblot should still be performed.

Diagnosis of Lyme disease in the pediatric acute care setting

PURPOSE OF REVIEW

We review the current evidence concerning the diagnosis of Lyme disease in children for application in the acute care setting.

RECENT FINDINGS

Recent studies suggest that Lyme disease incidence is substantially higher than previously described. Although efforts are ongoing to identify alternative testing strategies, two-tiered serologic testing remains the diagnostic standard in children with compatible clinical syndromes. Published clinical prediction rules can assist clinicians caring for children with potential Lyme disease.

SUMMARY

Two-tiered serologic testing remains the mainstay of the diagnosis of Lyme disease. To minimize the risk of a false positive test, serologic testing should be limited to those children with symptoms compatible with Lyme disease with potential exposure to ticks from endemic regions.

Assessment of antibodies against surface and outer membrane proteins of Anaplasma phagocytophilum in Lyme borreliosis and tick-borne encephalitis paediatric patients

To examine evidence of positive antibodies against immunogenic proteins of Anaplasma phagocytophilum in patients with other tick-borne infections and to diagnose possible co-infections, 412 serum specimens were tested by immunoblotting using three specific Anaplasma antigens: surface proteins p44 and Asp62 and outer membrane protein A (OmpA). In total, 284 serum samples from children with Lyme borreliosis and 12 serum samples from children with tick-borne encephalitis were tested. Sera from patients with viral aseptic meningitis (n = 47) and from blood donors (n = 69) were used as controls. Among all serum specimens from patients with tick-borne infections submitted for this study, six samples (2·0%) showed positive IgM reactions and seven samples (2·4%) were IgG positive for A. phagocytophilum by immunoblot. Borderline reactivity was found in 30 samples (10·14%) for IgM and 36 samples (12·2%) for IgG. The difference between patients and blood donors was statistically significant for IgM (P = 0·006) and for IgG (P = 0·0007) antibodies. A statistically significant result was obtained for IgG (P = 0·02) but not for IgM between patients and children with aseptic meningitis. Immunoblot using three specific antigens provides novel information about the positivity of antibodies to A. phagocytophilum in children with other tick-borne infections. Taking into account clinical and laboratory findings of children despite antibody positivity, no case of human granulocytic anaplasmosis was demonstrated.

Epidemiology of Lyme Disease, Nova Scotia, Canada, 2002-2013

Nova Scotia has the highest reported incidence in Canada, but risk is localized to identified disease-endemic regions.

Ixodes scapularis ticks, which transmit Borreliaburgdorferi, the causative agent of Lyme disease (LD), are endemic to at least 6 regions of Nova Scotia, Canada. To assess the epidemiology and prevalence of LD in Nova Scotia, we analyzed data from 329 persons with LD reported in Nova Scotia during 2002–2013. Most patients reported symptoms of early localized infection with rash (89.7%), influenza-like illness (69.6%), or both; clinician-diagnosed erythema migrans was documented for 53.2%. In a separate serosurvey, of 1,855 serum samples screened for antibodies to B.burgdorferi, 2 were borderline positive (both with an indeterminate IgG on Western blot), resulting in an estimated seroprevalence of 0.14% (95% CI 0.02%–0.51%). Although LD incidence in Nova Scotia has risen sharply since 2002 and is the highest in Canada (16/100,000 population in 2013), the estimated number of residents with evidence of infection is low, and risk is localized to currently identified LD-endemic regions.

Diagnosis, Treatment, and Prevention of Lyme Disease, Human Granulocytic Anaplasmosis, and Babesiosis: A Review

IMPORTANCE

Lyme disease, human granulocytic anaplasmosis (HGA), and babesiosis are emerging tick-borne infections.

OBJECTIVE

To provide an update on diagnosis, treatment, and prevention of tick-borne infections.

EVIDENCE REVIEW

Search of PubMed and Scopus for articles on diagnosis, treatment, and prevention of tick-borne infections published in English from January 2005 through December 2015.

FINDINGS

The search yielded 3550 articles for diagnosis and treatment and 752 articles for prevention. Of these articles, 361 were reviewed in depth. Evidence supports the use of US Food and Drug Administration-approved serologic tests, such as an enzyme immunoassay (EIA), followed by Western blot testing, to diagnose extracutaneous manifestations of Lyme disease. Microscopy and polymerase chain reaction assay of blood specimens are used to diagnose active HGA and babesiosis. The efficacy of oral doxycycline, amoxicillin, and cefuroxime axetil for treating Lyme disease has been established in multiple trials. Ceftriaxone is recommended when parenteral antibiotic therapy is recommended. Multiple trials have shown efficacy for a 10-day course of oral doxycycline for treatment of erythema migrans and for a 14-day course for treatment of early neurologic Lyme disease in ambulatory patients. Evidence indicates that a 10-day course of oral doxycycline is effective for HGA and that a 7- to 10-day course of azithromycin plus atovaquone is effective for mild babesiosis. Based on multiple case reports, a 7- to 10-day course of clindamycin plus quinine is often used to treat severe babesiosis. A recent study supports a minimum of 6 weeks of antibiotics for highly immunocompromised patients with babesiosis, with no parasites detected on blood smear for at least the final 2 weeks of treatment.

CONCLUSIONS AND RELEVANCE

Evidence is evolving regarding the diagnosis, treatment, and prevention of Lyme disease, HGA, and babesiosis. Recent evidence supports treating patients with erythema migrans for no longer than 10 days when doxycycline is used and prescription of a 14-day course of oral doxycycline for early neurologic Lyme disease in ambulatory patients. The duration of antimicrobial therapy for babesiosis in severely immunocompromised patients should be extended to 6 weeks or longer.

Five-Antigen Fluorescent Bead-Based Assay for Diagnosis of Lyme Disease

The systematically difficult task of diagnosing Lyme disease can be simplified by sensitive and specific laboratory tests. The currently recommended two-tier test for serology is highly specific but falls short in sensitivity, especially in the early acute phase. We previously examined serially collected serum samples from Borrelia burgdorferi-infected rhesus macaques and defined a combination of antigens that could be utilized for detection of infection at all phases of disease in humans. The five B. burgdorferi antigens, consisting of OspC, OspA, DbpA, OppA2, and the C6 peptide, were combined into a fluorescent cytometric bead-based assay for the detection of B. burgdorferi antigen-specific IgG antibodies. Samples from Lyme disease patients and controls were used to determine the diagnostic value of this assay. Using this sample set, we found that our five-antigen multiplex IgG assay exhibited higher sensitivity (79.5%) than the enzyme immunoassay (EIA) (76.1%), the two-tier test (61.4%), and the C6 peptide enzyme-linked immunosorbent assay (ELISA) (77.2%) while maintaining specificity over 90%. When detection of IgM was added to the bead-based assay, the sensitivity improved to 91%, but at a cost of reduced specificity (78%). These results indicate that the rational combination of antigens in our multiplex assay may offer an improved serodiagnostic test for Lyme disease.