High seroprevalence of Borrelia miyamotoi antibodies in forestry workers and individuals suspected of human granulocytic anaplasmosis in the Netherlands

Spatiotemporal distribution of Borrelia miyamotoi (Spirochaetales: Spirochaetaceae) and coinfection with other tick-borne pathogens in host-seeking Ixodes scapularis (Acari: Ixodidae) from New York State, USA

Blacklegged ticks (Ixodes scapularis Say, Acari: Ixodidae) were collected from 432 locations across New York State (NYS) during the summer and autumn of 2015-2020 to determine the prevalence and geographic distribution of Borrelia miyamotoi (Spirochaetales: Spirochaetaceae) and coinfections with other tick-borne pathogens. A total of 48,386 I. scapularis were individually analyzed using a multiplex real-time polymerase chain reaction assay to simultaneously detect the presence of Bo. miyamotoi, Borrelia burgdorferi (Spirochaetales: Spirochaetaceae), Anaplasma phagocytophilum (Rickettsiales: Anaplasmataceae), and Babesia microti (Piroplasmida: Babesiidae). Overall prevalence of Bo. miyamotoi in host-seeking nymphs and adults varied geographically and temporally at the regional level. The rate of polymicrobial infection in Bo. miyamotoi-infected ticks varied by developmental stage, with certain co-infections occurring more frequently than expected by chance. Entomological risk of exposure to Bo. miyamotoi-infected nymphal and adult ticks (entomological risk index [ERI]) across NYS regions in relation to human cases of Bo. miyamotoi disease identified during the study period demonstrated spatial and temporal variation. The relationship between select environmental factors and Bo. miyamotoi ERI was explored using generalized linear mixed effects models, resulting in different factors significantly impacting ERI for nymphs and adult ticks. These results can inform estimates of Bo. miyamotoi disease risk and further our understanding of Bo. miyamotoi ecological dynamics in regions where this pathogen is known to occur.

Human Borrelia miyamotoi Infection in North America

Borrelia miyamotoi is an emerging pathogen that causes a febrile illness and is transmitted by the same hard-bodied (ixodid) ticks that transmit several other pathogens, including Borrelia species that cause Lyme disease. B. miyamotoi was discovered in 1994 in Ixodes persulcatus ticks in Japan. It was first reported in humans in 2011 in Russia. It has subsequently been reported in North America, Europe, and Asia. B. miyamotoi infection is widespread in Ixodes ticks in the northeastern, northern Midwestern, and far western United States and in Canada. In endemic areas, human B. miyamotoi seroprevalence averages from 1 to 3% of the population, compared with 15 to 20% for B. burgdorferi. The most common clinical manifestations of B. miyamotoi infection are fever, fatigue, headache, chills, myalgia, arthralgia, and nausea. Complications include relapsing fever and rarely, meningoencephalitis. Because clinical manifestations are nonspecific, diagnosis requires laboratory confirmation by PCR or blood smear examination. Antibiotics are effective in clearing infection and are the same as those used for Lyme disease, including doxycycline, tetracycline, erythromycin, penicillin, and ceftriaxone. Preventive measures include avoiding areas where B. miyamotoi-infected ticks are found, landscape management, and personal protective strategies such as protective clothing, use of acaricides, and tick checks with rapid removal of embedded ticks.

Borrelia miyamotoi a neglected tick-borne relapsing fever spirochete in Thailand

Borrelia miyamotoi is a relapsing fever spirochete that shares the same vector as Lyme disease causing Borrelia. This epidemiological study of B. miyamotoi was conducted in rodent reservoirs, tick vectors and human populations simultaneously. A total of 640 rodents and 43 ticks were collected from Phop Phra district, Tak province, Thailand. The prevalence rate for all Borrelia species was 2.3% and for B. miyamotoi was 1.1% in the rodent population, while the prevalence rate was quite high in ticks collected from rodents with an infection rate of 14.5% (95% CI: 6.3-27.6%). Borrelia miyamotoi was detected in Ixodes granulatus collected from Mus caroli and Berylmys bowersi, and was also detected in several rodent species (Bandicota indica, Mus spp., and Leopoldamys sabanus) that live in a cultivated land, increasing the risk of human exposure. Phylogenetic analysis revealed that the B. miyamotoi isolates detected in rodents and I. granulatus ticks in this study were similar to isolates detected in European countries. Further investigation was conducted to determine the serological reactivity to B. miyamotoi in human samples received from Phop Phra hospital, Tak province and in rodents captured from Phop Phra district using an in-house, direct enzyme-linked immunosorbent assay (ELISA) assay with B. miyamotoi recombinant glycerophosphodiester-phosphodiesterase (rGlpQ) protein as coated antigen. The results showed that 17.9% (15/84) of human patients and 9.0% (41/456) of captured rodents had serological reactivity to B. miyamotoi rGlpQ protein in the study area. While a low level of IgG antibody titers (100-200) was observed in the majority of seroreactive samples, higher titers (400-1,600) were also detected in both humans and rodents. This study provides the first evidence of B. miyamotoi exposure in human and rodent populations in Thailand and the possible roles of local rodent species and Ixodes granulatus tick in its enzootic transmission cycle in nature.

Prevalence and clinical manifestation of Borrelia miyamotoi in Ixodes ticks and humans in the northern hemisphere: a systematic review and meta-analysis

BACKGROUND

Various studies have evaluated the infection of Ixodes ticks and humans with the relapsing fever spirochaete Borrelia miyamotoi. However, to our knowledge, the prevalence of infection and disease has not been assessed systematically. We aimed to examine the prevalence of B miyamotoi in Ixodes ticks and humans, and the disease it can cause, in the northern hemisphere.

METHODS

For this systematic review and meta-analysis, we searched PubMed and Web of Science up to March 1, 2021. Studies assessing Ixodes tick infection published since Jan 1, 2011 were eligible, whereas no time limitation was placed on reports of human infection and disease. We extracted B miyamotoi test positivity ratios and used a random-effects model to calculate estimated proportions of infected ticks, infected humans, and human disease with 95% CI. This study was registered with PROSPERO, CRD42021268996.

FINDINGS

We identified 730 studies through database searches and 316 additional studies that referenced two seminal articles on B miyamotoi. Of these 1046 studies, 157 were included in the review, reporting on 165 637 questing ticks, 45 608 unique individuals, and 504 well described cases of B miyamotoi disease in humans. In ticks, the highest prevalence of B miyamotoi was observed in Ixodes persulcatus (2·8%, 95% CI 2·4-3·1) and the lowest in Ixodes pacificus (0·7%, 0·6-0·8). The overall seroprevalence in humans was 4·4% (2·8-6·3), with significantly (p<0·0001) higher seroprevalences in the high-risk group (4·6%, 2·6-7·1), participants with confirmed or suspected Lyme borreliosis (4·8%, 1·8-8·8), and individuals suspected of having a different tick-borne disease (11·9%, 5·6-19·9) than in healthy controls (1·3%, 0·4-2·8). Participants suspected of having a different tick-borne disease tested positive for B miyamotoi by PCR significantly more often than did the high-risk group (p=0·025), with individuals in Asia more likely to test positive than those in the USA (odds ratio 14·63 [95% CI 2·80-76·41]).

INTERPRETATION

B miyamotoi disease should be considered an emerging infectious disease, especially in North America and Asia. Prospective studies and increased awareness are required to obtain further insights into the burden of disease.

FUNDING

ZonMW and the European Regional Development Fund (Interreg).

Novel approaches for the serodiagnosis of louse-borne relapsing fever

Louse-borne relapsing fever (LBRF) caused by B. recurrentis is a poverty-related and neglected infectious disease with an endemic focus in the Horn of Africa. Re-emergence of the disease occurred in Europe during the refugee crisis in 2015 and sporadic outbreaks were frequently reported in Eastern Africa where poor settings lack affordable diagnostics. Currently, there are no validated in vitro assays available for the serodiagnosis of LBRF. The aim of this study was to develop novel and reliable immunoassays by investigating clinically suspected and culture-confirmed serum samples from LBRF patients and a broad panel of serum samples from patients with other spirochetal, bacterial, and parasitic diseases. We identified two immunoreactive antigens (complement-inhibiting protein CihC and the glycerophosphodiester phosphodiesterase GlpQ of B. recurrentis) as the most promising target candidates leading to the evaluation of two immunoassays (line immunoblot and ELISA) for IgM and IgG. To optimize the IgM immunoassay, we conducted a bioinformatic approach to localize the relevant immunogenic regions within CihC. By utilizing a N-terminal CihC fragment, the sensitivity and specificity of both immunoassays (CihC and GlpQ) were high (IgM: sensitivity 100%, specificity of 89.9%, IgG: sensitivity 100%, specificity 99.2%). In conclusion, our findings indicate the diagnostic potential of CihC and GlpQ as valuable markers for the serodiagnosis of LBRF even at early time points of infection. Here, we provide strong evidence for the utilization of these immunoassays as reliable tools in clinical practice.

A One Health Evaluation of the Surveillance Systems on Tick-Borne Diseases in the Netherlands, Spain and Italy

Simple Summary

Ixodid ticks and tick-borne diseases are expanding their geographical range, but surveillance activities vary among countries. We analysed the surveillance systems in place in the Netherlands, Spain and Italy, to identify ideal elements to monitor tick-borne diseases, by using a One Health evaluation protocol. We identified differences among the three surveillance systems, with the Dutch initiative showing a high level of transdisciplinary collaboration, good identification of the actors and engagement of the public in research and education. Measurable outcomes have been generated, such as the reduction in tick bites and the discovery of new pathogens and tick species. In Italy and Spain, surveillance systems are based on compulsory notification to health authorities; legislation seems relevant but law enforcement alongside the availability of economic resources is rather fragmented and limited to the most severe diseases. The non-scientific community is marginally considered and collaborations are limited to local initiatives. Research activities in both countries have mostly contributed to gaining knowledge on the distribution of tick species and the discovery of new pathogens. Although all TBD surveillance plans comply with the EU regulations, the initiatives characterised by trans-disciplinary collaboration may be more effective for the surveillance and prevention of tick-transmitted diseases.

Abstract

To identify ideal elements for the monitoring and prevention of tick-borne diseases (TBD), we analysed the surveillance systems in place in the Netherlands, Spain and Italy. We applied a semi-quantitative evaluation to identify outcomes and assess the degree of One Health implementation. Differences emerged in the surveillance initiatives, as well as the One Health scores. The Dutch surveillance is dominated by a high level of transdisciplinary and trans-sectoral collaboration, enabling communication and data sharing among actors. Different project-based monitoring, research and educational activities are centrally coordinated and the non-scientific community is actively involved. All this yielded measurable health outcomes. In Italy and Spain, TBD surveillance and reporting systems are based on compulsory notification. Law enforcement, alongside dedicated time and availability of economic resources, is fragmented and limited to the most severe health issues. Veterinary and human medicine are the most involved disciplines, with the first prevailing in some contexts. Stakeholders are marginally considered and collaborations limited to local initiatives. Research activities have mostly contributed to gaining knowledge on the distribution of tick vectors and discovery of new pathogens. Although all TBD surveillance plans comply with EU regulations, initiatives characterised by transdisciplinary collaboration may be more effective for the surveillance and prevention of TBD.

Frequency and Geographic Distribution of Borrelia miyamotoi, Borrelia burgdorferi, and Babesia microti Infections in New England Residents

BACKGROUND

Borrelia miyamotoi is a relapsing fever spirochete that relatively recently has been reported to infect humans. It causes an acute undifferentiated febrile illness that can include meningoencephalitis and relapsing fever. Like Borrelia burgdorferi, it is transmitted by Ixodes scapularis ticks in the northeastern United States and by Ixodes pacificus ticks in the western United States. Despite reports of clinical cases from North America, Europe, and Asia, the prevalence, geographic range, and pattern of expansion of human B. miyamotoi infection are uncertain. To better understand these characteristics of B. miyamotoi in relation to other tickborne infections, we carried out a cross-sectional seroprevalence study across New England that surveyed B. miyamotoi, B. burgdorferi, and Babesia microti infections.

METHODS

We measured specific antibodies against B. miyamotoi, B. burgdorferi, and B. microti among individuals living in 5 New England states in 2018.

RESULTS

Analysis of 1153 serum samples collected at 11 catchment sites showed that the average seroprevalence for B. miyamotoi was 2.8% (range, 0.6%-5.2%), which was less than that of B. burgdorferi (11.0%; range, 6.8%-15.6%) and B. microti (10.0%; range, 6.5%-13.6%). Antibody screening within county residence in New England showed varying levels of seroprevalence for these pathogens but did not reveal a vectoral geographical pattern of distribution.

CONCLUSIONS

Human infections caused by B. miyamotoi, B. burgdorferi, and B. microti are widespread with varying prevalence throughout New England.

Tick magnets: The occupational risk of tick‐borne disease exposure in forestry workers in New York

Background

Outdoor workers, such as forestry workers, are at an increased risk for contracting tick‐borne diseases due to their prolonged time spent in tick habitats. Although well studied in Europe, no studies have been conducted with forestry workers in the Northeastern United States since 1990s.

Methods

Full‐time forestry workers and two comparison groups (volunteer firefighter/first responders and indoor/healthcare workers) within New York State Department of Environmental Conservation Regions 3, 4, 5, 6, and 7 were recruited for this cross‐sectional seroprevalence study. Blood draws were conducted to test for antibodies to Lyme, anaplasmosis, babesiosis, and ehrlichiosis. Surveys were administered to determine personal risk factors and protective behaviors.

Results

Between November 2020 and May 2021, 256 (105 forestry, 101 firefighter/first responder, and 50 indoor/healthcare) workers participated in this study. Forestry workers had a probability of testing positive nearly twice as high for any tick‐borne disease (14%) compared to firefighter/first responders (8%) and to indoor workers (6%); however, this difference was not statistically significant (P = .140). Forestry workers were more likely to find embedded ticks on themselves (f = 33.26, P < .0001 vs both comparison groups) and to have been previously diagnosed with a tick‐borne disease (P = .001 vs firefighter/first responders, P = .090 vs indoor/healthcare workers).

Conclusions

This pilot study suggests a higher proportion of tick‐borne disease risk among forestry workers compared to firefighters/first responders and indoor/healthcare workers with lesser exposure. A larger study to confirm or refute this pilot data could help optimize mitigation/prevention strategies.

Distribution of Borrelia burgdorferi s.l. and Borrelia miyamotoi in Ixodes tick populations in Northern Germany, co-infections with Rickettsiales and assessment of potential influencing factors

To determine Borrelia spp. (Spirochaetales: Spirochaetaceae) prevalence and species distribution in Northern Germany, Ixodes ticks were sampled from April to October in 2018 and 2019 by the flagging method at three locations each in five regions. Analysis by quantitative real-time PCR of 3150 individual ticks revealed an overall prevalence of 30.6%, without significant differences between tick stages (31.7% positive adults, 28.6% positive nymphs). Significant differences were observed in seasonal infection rates, but not between regions, landscape types or sampling years. Analysis of co-infections with Rickettsiales indicated a negative association between Borrelia and Anaplasma phagocytophilum infection. The most frequent Borrelia species differentiated by Reverse Line Blot were B. afzelii and B. garinii/B. bavariensis, followed by B. valaisiana, B. burgdorferi sensu stricto, B. spielmanii and B. lusitaniae. Furthermore, B. miyamotoi was identified in 12.9% of differentiable samples. No effect of region nor landscape type on species composition was found, but significant variations in the distribution at the different sampling sites within a region were observed. The detected monthly fluctuations in prevalence and the differences in intra-regional Borrelia species distribution underline the importance of long-term and multi-location monitoring of Borrelia spp. in ticks as an essential part of public health assessment.

Laboratory Methods for Detection of Infectious Agents and Serological Response in Humans With Tick-Borne Infections: A Systematic Review of Evaluations Based on Clinical Patient Samples

Background: For the most important and well-known infections spread by Ixodes ticks, Lyme borreliosis (LB) and tick-borne encephalitis (TBE), there are recommendations for diagnosis and management available from several health authorities and professional medical networks. However, other tick-borne microorganisms with potential to cause human disease are less known and clear recommendations on diagnosis and management are scarce. Therefore, we performed a systematic review of published studies and reviews focusing on evaluation of laboratory methods for clinical diagnosis of human tick-borne diseases (TBDs), other than acute LB and TBE. The specific aim was to evaluate the scientific support for laboratory diagnosis of human granulocytic anaplasmosis, rickettsiosis, neoehrlichiosis, babesiosis, hard tick relapsing fever, tularemia and bartonellosis, as well as tick-borne co-infections and persistent LB in spite of recommended standard antibiotic treatment.

Methods: We performed a systematic literature search in 11 databases for research published from 2007 through 2017, and categorized potentially relevant references according to the predefined infections and study design. An expert group assessed the relevance and eligibility and reviewed the articles according to the QUADAS (diagnostic studies) or AMSTAR (systematic reviews) protocols, respectively. Clinical evaluations of one or several diagnostic tests and systematic reviews were included. Case reports, non-human studies and articles published in other languages than English were excluded.

Results: A total of 48 studies fulfilled the inclusion criteria for evaluation. The majority of these studies were based on small sample sizes. There were no eligible studies for evaluation of tick-borne co-infections or for persistent LB after antibiotic treatment.

Conclusions: Our findings highlight the need for larger evaluations of laboratory tests using clinical samples from well-defined cases taken at different time-points during the course of the diseases. Since the diseases occur at a relatively low frequency, single-center cross-sectional studies are practically not feasible, but multi-center case control studies could be a way forward.

Ticking on Pandora's box: a prospective case-control study into 'other' tick-borne diseases

BACKGROUND

Tick-borne pathogens other than Borrelia burgdorferi sensu lato - the causative agent of Lyme borreliosis - are common in Ixodes ricinus ticks. How often these pathogens cause human disease is unknown. In addition, diagnostic tools to identify such diseases are lacking or reserved to research laboratories. To elucidate their prevalence and disease burden, the study 'Ticking on Pandora's Box' has been initiated, a collaborative effort between Amsterdam University Medical Center and the National Institute for Public Health and the Environment.

METHODS

The study investigates how often the tick-borne pathogens Anaplasma phagocytophilum, Babesia species, Borrelia miyamotoi, Neoehrlichia mikurensis, spotted fever group Rickettsia species and/or tick-borne encephalitis virus cause an acute febrile illness after tick-bite. We aim to determine the impact and severity of these tick-borne diseases in the Netherlands by measuring their prevalence and describing their clinical picture and course of disease. The study is designed as a prospective case-control study. We aim to include 150 cases - individuals clinically suspected of a tick-borne disease - and 3 matched healthy control groups of 200 persons each. The controls consist respectively of a group of individuals with either a tick-bite without complaints, the general population and of healthy blood donors. During a one-year follow-up we will acquire blood, urine and skin biopsy samples and ticks at baseline, 4 and 12 weeks. Additionally, participants answer modified versions of validated questionnaires to assess self-reported symptoms, among which the SF-36, on a 3 monthly basis.

DISCUSSION

This article describes the background and design of the study protocol of 'Ticking on Pandora's Box'. With our study we hope to provide insight into the prevalence, clinical presentation and disease burden of the tick-borne diseases anaplasmosis, babesiosis, B. miyamotoi disease, neoehrlichiosis, rickettsiosis and tick-borne encephalitis and to assist in test development as well as provide recommendations for national guidelines.

TRIAL REGISTRATION

NL9258 (retrospectively registered at Netherlands Trial Register, trialregister.nl in in February 2021).

Underrecognized Tickborne Illnesses: Borrelia Miyamotoi and Powassan Virus

Over the past 2 decades, tickborne disease has been increasingly recognized as a threat to humans as a result of the growing geographic range of ticks. This review describes 2 tickborne diseases, Borrelia miyamotoi and Powassan virus, that likely have a significant impact on humans, yet are underdiagnosed compared to most other tickborne diseases. We performed a literature search from 2015 to 2020. Borrelia miyamotoi is a tickborne pathogen that infects and co-infects ticks along with other pathogens, including Borrelia burgdorferi. Because B miyamotoi infects the same Ixodes ticks as B burgdorferi, B miyamotoi may cover a similar geographic range. B miyamotoi infection may be underdiagnosed for 2 reasons. First, a presumptive treatment approach to Lyme disease may result in B miyamotoi infection treatment without identification of the actual cause. Second, the absence of readily available testing and diagnostic criteria makes it difficult to diagnose B miyamotoi infection. Powassan virus is a tickborne flavivirus similar to the dengue virus. Powassan virus disease appears to have an asymptomatic or minimally symptomatic presentation in most people but can cause devastating and fatal encephalitis. The Powassan virus may be transmitted in less than 15 min of tick feeding. Powassan virus disease is a difficult diagnosis because testing capabilities are limited and because there may be co-infection with other tickborne pathogens.

Prevalence and prediction of Lyme disease in Hainan province

Lyme disease (LD) is one of the most important vector-borne diseases worldwide. However, there is limited information on the prevalence and risk analysis using correlated factors in the tropical areas. A total of 1583 serum samples, collected from five hospitals of Hainan Province, were tested by immunofluorescence assay (IFA) and western blot (WB) analyses using anti-Borrelia burgdorferi antibodies. Then, we mapped the distribution of positive rate (by IFA) and the spread of confirmed Lyme patients (by WB). Using ArcGIS, we compiled host-vector-human interactions and correlated data as risk factor layers to predict LD risk in Hainan Province. There are three LD hotspots, designated hotspot I, which is located in central Hainan, hotspot II, which contains Sanya district, and hotspot III, which lies in the Haikou-Qiongshan area. The positive rate (16.67% by IFA) of LD in Qiongzhong, located in hotspot I, was higher than that in four other areas. Of confirmed cases of LD, 80.77% of patients (42/52) whose results had been confirmed by WB were in hotspots I and III. Hotspot II, with unknowed prevalence of LD, need to be paid more attention considering human-vector interaction. Wuzhi and Limu mountains might be the most important areas for the prevalence of LD, as the severe host-vector and human-vector interactions lead to a potential origin site for LD. Qiongzhong is the riskiest area and is located to the east of Wuzhi Mountain. In the Sanya and Haikou-Qiongshan area, intervening in the human-vector interaction would help control the prevalence of LD.

Borrelia miyamotoi-An Emerging Human Tick-Borne Pathogen in Europe

Borrelia miyamotoi is classified as a relapsing fever spirochete. Although B. miyamotoi is genetically and ecologically distinct from Borrelia burgdorferi sensu lato, both microorganisms are transmitted by the same Ixodes tick species. B. miyamotoi was detected in I. persulcatus ticks in 1994 in Japan. A phylogenetic analysis based on selected sequences of B. miyamotoi genome revealed genetic differences between isolates from Asia, North America, and Europe, which are clearly separated into three genotypes. Symptomatic human cases of Borrelia miyamotoi disease (BMD) were first reported in 2011 in Russia and then in North America, Europe, and Asia. The most common clinical manifestation of BMD is fever with flu-like symptoms. Several differences in rare symptoms (thrombocytopenia, monocytosis, cerebrospinal fluid pleocytosis, or symptoms related to the central nervous system) have been noted among cases caused by Asian, European, and American types of B. miyamotoi. BMD should be considered in the diagnosis of patients after tick bites, particularly with meningoencephalitis, without anti-Borrelia antibodies in the cerebrospinal fluid. This review describes the biology, ecology, and potential of B. miyamotoi as a tick-borne pathogen of public health concern, with particular emphasis on Europe.

Borrelia burgdorferi and Borrelia miyamotoi seroprevalence in California blood donors

The western blacklegged tick, Ixodes pacificus, an important vector in the western United States of two zoonotic spirochetes: Borrelia burgdorferi (also called Borreliella burgdorferi), causing Lyme disease, and Borrelia miyamotoi, causing a relapsing fever-type illness. Human cases of Lyme disease are well-documented in California, with increased risk in the north coastal areas and western slopes of the Sierra Nevada range. Despite the established presence of B. miyamotoi in the human-biting I. pacificus tick in California, clinical cases with this spirochete have not been well studied. To assess exposure to B. burgdorferi and B. miyamotoi in California, and to address the hypothesis that B. miyamotoi exposure in humans is similar in geographic range to B. burgdorferi, 1,700 blood donor sera from California were tested for antibodies to both pathogens. Sampling was from high endemic and low endemic counties for Lyme disease in California. All sera were screened using the C6 ELISA. All C6 positive and equivocal samples and nine randomly chosen C6 negative samples were further analyzed for B. burgdorferi antibody using IgG western blot and a modified two ELISA test system and for B. miyamotoi antibody using the GlpQ ELISA and B. miyamotoi whole cell sonicate western blot. Of the 1,700 samples tested in series, eight tested positive for antibodies to B. burgdorferi (0.47%, Exact 95% CI: 0.20, 0.93) and two tested positive for antibodies to B. miyamotoi (0.12%, Exact 95% CI: 0.01, 0.42). There was no statistically significant difference in seroprevalence for either pathogen between high and low Lyme disease endemic counties. Our results confirm a low frequency of Lyme disease and an even lower frequency of B. miyamotoi exposure among adult blood donors in California; however, our findings reinforce public health messaging that there is risk of infection by these emerging diseases in the state.

Glycerophosphodiester Phosphodiesterase Identified as Non-Reliable Serological Marker for Borrelia miyamotoi Disease

The relapsing fever group Borrelia miyamotoi is an emerging tick-borne pathogen. Diagnosis of infection is currently mainly based on serological methods detecting antibodies against B. miyamotoi glycerophosphodiester phosphodiesterase (GlpQ). Here, we scrutinized the reliability of GlpQ as a diagnostic marker and compared the seroprevalence in different study populations and by applying various immunoblotting methods. Antibodies were detected in the sera of 7/53 hunters and in 1/11 sera of Lyme neuroborreliosis patients. Furthermore, 17/74 sera of persons with high concentrations of anti-Borrelia burgdorferi sensu lato (α-Bbsl) antibodies reacted strongly with B. miyamotoi GlpQ in immunoblots. The B. miyamotoi GlpQ seroprevalence was 7/50 in α-Bbsl negative persons. In healthy blood donors from commercial suppliers and from the Austrian Red Cross, seroprevalences were 5/14 and 10/35, respectively. Strikingly, two B. miyamotoi PCR-positive cases from Austria had negative GlpQ serology, indicating poor sensitivity. Finally, when we analyzed sera of dogs, we found α-B. miyamotoi GlpQ antibody seroprevalence in tick-free dogs (n = 10) and in tick-exposed dogs (n = 19) with 2/10 and 8/19, respectively. Thus, our results indicate that GlpQ-based B. miyamotoi serology holds neither specificity nor sensitivity.

A new Borrelia on the block: Borrelia miyamotoi - a human health risk?

Background

Borrelia miyamotoi clusters phylogenetically among relapsing fever borreliae, but is transmitted by hard ticks. Recent recognition as a human pathogen has intensified research into its ecology and pathogenic potential.

Aims

We aimed to provide a timely critical integrative evaluation of our knowledge on B. miyamotoi, to assess its public health relevance and guide future research.

Methods

This narrative review used peer-reviewed literature in English from January 1994 to December 2018.

Results

Borrelia miyamotoi occurs in the world’s northern hemisphere where it co-circulates with B. burgdorferi sensu lato, which causes Lyme disease. The two borreliae have overlapping vertebrate and tick hosts. While ticks serve as vectors for both species, they are also reservoirs for B. miyamotoi. Three B. miyamotoi genotypes are described, but further diversity is being recognised. The lack of sufficient cultivable isolates and vertebrate models compromise investigation of human infection and its consequences. Our understanding mainly originates from limited case series. In these, human infections mostly present as influenza-like illness, with relapsing fever in sporadic cases and neurological disease reported in immunocompromised patients. Unspecific clinical presentation, also occasionally resulting from Lyme- or other co-infections, complicates diagnosis, likely contributing to under-reporting. Diagnostics mainly employ PCR and serology. Borrelia miyamotoi infections are treated with antimicrobials according to regimes used for Lyme disease.

Conclusions

With co-infection of tick-borne pathogens being commonplace, diagnostic improvements remain important. Developing in vivo models might allow more insight into human pathogenesis. Continued ecological and human case studies are key to better epidemiological understanding, guiding intervention strategies.

Assessment of Borrelia miyamotoi in febrile patients and ticks in Alsace, an endemic area for Lyme borreliosis in France

Background

Borrelia miyamotoi is a relapsing fever Borrelia species transmitted by ticks of the Ixodes ricinus complex. Human disease caused by B. miyamotoi was first described in Russia and later in the USA and Japan. Additionally, five cases of meningoencephalitis in immunocompromised patients and one case in an apparently immunocompetent patient were described.

Methods

We investigated the presence of B. miyamotoi in I. ricinus nymphs and in patients suspected of human granulocytic anaplasmosis, in Alsace (France), an endemic area for I. ricinus ticks and Lyme borreliosis, using direct (PCR) and indirect diagnosis (glycerophosphoryldiester-phosphodiesterase (GlpQ) serology).

Results

Borrelia miyamotoi was found in 2.2% of 4354 ticks collected between 2013 and 2016. None of the 575 blood samples, collected from the patients suspected of HGA, was found positive for B. miyamotoi by PCR. Acute and late sera from 138 of these 575 patients were available. These paired sera were tested for IgM and IgG antibodies against the B. miyamotoi GlpQ antigen. A total of 14 out of 138 patients had at least one positive parameter (i.e. anti-GlpQ IgG and/or IgM). One patient seroconverted for IgG, and three had isolated IgM in the acute serum. These three patients were treated with doxycycline which could have prevented seroconversion. After reviewing clinical data and other biological tests performed, co-exposure among different microorganisms vectored by ticks or serological cross-reactivity could not be ruled out in these different cases. One patient had persistent IgG, which strongly suggests previous exposure to B. miyamotoi.

Conclusions

Humans can be exposed to B. miyamotoi through tick bites in Alsace. We present serological data for possible B. miyamotoi exposure or infection of patients with fever after tick bite. Future studies should determine the incidence, clinical course and burden of this emerging tick-borne disease in other parts of Western Europe.

Emerging Tick-Borne Diseases

Increases in tick-borne disease prevalence and transmission are important public health issues. Efforts to control these emerging diseases are frustrated by the struggle to control tick populations and to detect and treat infections caused by the pathogens that they transmit. This review covers tick-borne infectious diseases of nonrickettsial bacterial, parasitic, and viral origins. While tick surveillance and tracking inform our understanding of the importance of the spread and ecology of ticks and help identify areas of risk for disease transmission, the vectors are not the focus of this document. Here, we emphasize the most significant pathogens that infect humans as well as the epidemiology, clinical features, diagnosis, and treatment of diseases that they cause. Although detection via molecular or immunological methods has improved, tick-borne diseases continue to remain underdiagnosed, making the scope of the problem difficult to assess. Our current understanding of the incidence of tick-borne diseases is discussed in this review. An awareness of the diseases that can be transmitted by ticks in specific locations is key to detection and selection of appropriate treatment. As tick-transmitted pathogens are discovered and emerge in new geographic regions, our ability to detect, describe, and understand the growing public health threat must also grow to meet the challenge.

Borrelia prevalence and species distribution in ticks removed from humans in Germany, 2013-2017

Lyme borreliosis caused by spirochaetes of the Borrelia burgdorferi sensu lato (s.l.) complex is the most common tick-borne disease in Europe. In addition, the relapsing-fever spirochaete Borrelia miyamotoi, which has been associated with febrile illness and meningoencephalitis in immunocompromised persons, is present in Europe. This study investigated Borrelia prevalence and species distribution in ticks removed from humans and sent as diagnostic material to the Institute for Parasitology, University of Veterinary Medicine Hannover, in 2013-2017. A probe-based real-time PCR was carried out and Borrelia-positive samples were subjected to species determination by reverse line blot (RLB), including a B. miyamotoi-specific probe. The overall Borrelia-infection rate as determined by real-time PCR was 20.02 % (510/2547, 95 % CI: 18.48-21.63 %), with annual prevalences ranging from 17.17 % (90/524, 95 % CI: 14.04-20.68 %) in 2014 to 24.12 % (96/398, 95 % CI: 19.99-28.63 %) in 2015. In total, 271/475 (57.1 %) positive samples available for RLB were successfully differentiated. Borrelia afzelii was detected in 30.53 % of cases (145/475, 95 % CI: 26.41-34.89), followed by B. garinii/B. bavariensis (13.26 % [63/475], 95 % CI: 10.34-16.65). Borrelia valaisiana occurred in 5.89 % (28/475, 95 % CI: 3.95-8.41), B. spielmanii in 4.63 % (22/475, 95 % CI: 2.93-6.93), B. burgdorferi sensu stricto (s.s.)/B. carolinensis in 2.32 % (11/475, 95 % CI: 1.16-4.11), B. lusitaniae in 0.63 % (3/475, 95 % CI: 0.13-1.83) and B. bisettiae in 0.42 % (2/475, 95 % CI: 0.05-1.51) of positive ticks. Borrelia kurtenbachii was not detected, while B. miyamotoi was identified in 7.37 % (35/475, 95 % CI: 5.19-10.10) of real-time PCR-positive samples. Sanger sequencing of B. garinii/B. bavariensis-positive ticks revealed that the majority were B. garinii-infections (50/52 successfully amplified samples), while only 2 ticks were infected with B. bavariensis. Furthermore, 6/12 B. burgdorferi s.s./B. carolinensis-positive samples could be differentiated; all of them were identified as B. burgdorferi sensu stricto. Thirty-nine ticks (8.21 %, 95 % CI: 5.90-11.05) were coinfected with two different species. Comparison of the species distribution between ticks removed from humans in 2015 and questing ticks collected in the same year and the same area revealed a significantly higher B. afzelii-prevalence in diagnostic tick samples than in questing ticks, confirming previous observations. The obtained data indicate that Borrelia prevalence fluctuated in the same range as observed in a previous study, analysing the period from 2006 to 2012. Detection of B. miyamotoi in 7.37 % of Borrelia-positive samples points to the fact that clinicians should be aware of this pathogen as a differential diagnosis in cases of febrile illness.

Bacterial microbiota composition of Ixodes ricinus ticks: the role of environmental variation, tick characteristics and microbial interactions

Ecological factors, host characteristics and/or interactions among microbes may all shape the occurrence of microbes and the structure of microbial communities within organisms. In the past, disentangling these factors and determining their relative importance in shaping within-host microbiota communities has been hampered by analytical limitations to account for (dis)similar environmental preferences ('environmental filtering'). Here we used a joint species distribution modelling (JSDM) approach to characterize the bacterial microbiota of one of the most important disease vectors in Europe, the sheep tick Ixodes ricinus, along ecological gradients in the Swiss Alps. Although our study captured extensive environmental variation along elevational clines, the explanatory power of such large-scale ecological factors was comparably weak, suggesting that tick-specific traits and behaviours, microhabitat and -climate experienced by ticks, and interactions among microbes play an important role in shaping tick microbial communities. Indeed, when accounting for shared environmental preferences, evidence for significant patterns of positive or negative co-occurrence among microbes was found, which is indicative of competition or facilitation processes. Signals of facilitation were observed primarily among human pathogens, leading to co-infection within ticks, whereas signals of competition were observed between the tick endosymbiont Spiroplasma and human pathogens. These findings highlight the important role of small-scale ecological variation and microbe-microbe interactions in shaping tick microbial communities and the dynamics of tick-borne disease.

Dynamics of Spirochetemia and Early PCR Detection of Borrelia miyamotoi

We investigated whether Borrelia miyamotoi disease can be detected in its early stage by using PCR for borrelial 16S rRNA, which molecule (DNA or RNA) is the best choice for this test, and whether spirochetes are present in blood during the acute phase of B. miyamotoi disease. A total of 473 patients with a suspected tickborne infection in Yekaterinburg, Russia, in 2009, 2010, and 2015 were enrolled in this study. Blood samples were analyzed by using quantitative PCR or ELISA, and a diagnosis of borreliosis was confirmed for 310 patients. For patients with erythema migrans, 5 (3%) of 167 were positive for B. miyamotoi by PCR; for patients without erythema migrans, 65 (45%) of 143 were positive for B. miyamotoi by PCR. The median concentration for RNA was 3.8 times that for DNA. Median time for detection of B. miyamotoi in blood was 4 days.

[Follow-up of patients with Ixodes tick-borne borrelioses caused by Borrelia miyamotoi or Borrelia burgdorferi sensu lato]

Ixodes tick-borne borrelioses (ITBB) are caused by two different spirochetes: Borrelia from the group of Borrelia burgdorferi sensu lato, the agents of the classic Lyme borreliosis (LB), and Borrelia miyamotoi that belongs to the group of Borrelia causing tick-borne relapsing fevers. ITBB caused by B. miyamotoi (BM-ITBB) is a previously unknown infectious disease discovered in Russia. It is known that the LB sequelae may reduce the long-term life guality of convalescents.

AIM

To study the follow-up of those who have recovered from new BM-ITBB infection in comparison with persons who have had LB.

SUBJECTS AND METHODS

The investigation enrolled 41 patients with BM-ITBB and 41 patients with LB who were treated at the Republican Infectious Diseases Hospital of Udmurtia. Within a year after the disease, they were followed up through clinical and instrumental examination of cardiac performance, expanded biochemical analysis of blood and urine, which could; estimate kidney and liver functions, and psychological questioning.

RESULTS

Asthenic syndrome and complaints about and objective signs of cardiac dysfunctions persisted supraventricular extrasystoles, left ventricular diastolic dysfunction, and elevated and/or unstable systolic blood pressure were detected in 20-30% of the convalescents for a long time. Kidney dysfunctions were manifested in albuminuria and the decrease of glomerular filtration rate. A year following the disease, 10-20% patients had persistently elevated concentrations of alanine aminotransferase, aspartate aminotransferase, and C-reactive protein and had higher levels of total cholesterol and low-density lipoproteins. The pathological consequences of ITBB were polymorphic and varied in different patients; in general, only 68% of them showed health improvement.

CONCLUSION

We assume that a significant role in the pathogenesis of BM-ITBB and LB is played by vascular endothelial damage possibly associated with the inflammatory and autoimmune aspects of an immune response in Borrelia infection. The consequences of this damage may persist and even intensify during a year, which provokes chronic dysfunction of the heart, kidney, or liver in a number of convalescents.

A bead-based suspension array for the detection of Salmonella antibodies in pig sera

Background

Slaughter pigs are monitored for the presence of the zoonotic pathogen Salmonella, using both serology and bacteriology. ELISAs used to investigate pig herds are based on the detection of antibodies against components of the Salmonella cell envelope. Nearly all Salmonella isolates in food-producing animals are serovars of Salmonella enterica subspecies enterica, distributed over various serogroups as determined by the composition of their lipopolysaccharide (LPS). ELISAs for Salmonella serology are usually based on serogroup B and C1 LPS, often combined with serogroup D or E LPS. Although C2 LPS may improve serology, use of C2 LPS in a broad ELISA was never achieved.

Results

To enable detection of serum antibodies against Salmonella in pigs, a bead-based suspension array was developed with five LPS variants (B, 2× C1, C2, D1), each conjugated to a different bead set using triazine chemistry. Reactivity of the beads was confirmed with rabbit agglutination sera and with experimental pig sera. With a mixture of bead sets, 175 sera from slaughter pigs were investigated for the presence of antibodies against Salmonella. With a combination of ROC analysis (B and D LPS) and a prevalence estimation based on historic data (C LPS), individual cut-offs were defined for each LPS-conjugated bead set, and assay performance was evaluated.

Results of the suspension array (BC1C1C2D) suggest that more pigs are seroconverted than indicated by a commercial BC1D1-ELISA, and that most of these extra seropositive samples give a signal on one of the beads with C LPS. These results show that expansion of a standard panel with more C LPS variants improves antibody detection.

Conclusions

A suspension array for Salmonella serology in pigs was developed, that detects more seropositive sera than ELISA, which is achieved by expanding the panel of Salmonella LPS variants, including C2 LPS. The results demonstrate that bead-based suspension arrays allow for testing of pig sera, with the advantage of being able to set cut-offs per antigen. Ultimately, this type of assay can be applied in routine veterinary serology to test for antibodies against multiple Salmonella serovars (or other pathogens) in one single serum sample, using up-to-date antigen panels.

Electronic supplementary material

The online version of this article (10.1186/s12917-018-1541-x) contains supplementary material, which is available to authorized users.

Case control study: Serological evidence that Borrelia miyamotoi disease occurs nationwide in Japan

Since 2011, Borrelia miyamotoi disease (BMD) has been reported in five countries in the northern hemisphere. The causative agent of BMD is transmitted by Ixodes ticks, which are also vectors of Lyme disease borreliae. In this study, we examined 459 cases of clinically suspected Lyme disease (LD group), and found twelve cases that were seropositive for the glycerophosphodiester phosphodiesterase (GlpQ) antigen derived from B. miyamotoi. The retrospective surveillance revealed that the seroprevalence of anti-GlpQ in the LD group was significantly higher than in a healthy cohort. Seropositive cases were observed from spring through autumn when ticks are active, and the cases were geographically widespread, being found in Hokkaido-Tohoku, Kanto, Chubu, Kinki, and Kyushu-Okinawa regions. Seropositive cases for GlpQ were most frequent in the Chubu region (6.3%) where B. miyamotoi has been found in Ixodes ticks. Out of the twelve cases that were found in the LD group, three cases exhibited concomitant seropositivity to Lyme disease borreliae by western blot assay. This is the first report of serological surveillance for BMD in Japan, and we conclude that BMD occurs nationwide.

Shifts in Borrelia burgdorferi (s.l.) geno-species infections in Ixodes ricinus over a 10-year surveillance period in the city of Hanover (Germany) and Borrelia miyamotoi-specific Reverse Line Blot detection

BACKGROUND

Lyme borreliosis caused by spirochetes of the Borrelia burgdorferi (sensu lato) complex is still the most common tick-borne disease in Europe, posing a considerable threat to public health. The predominant vector in Europe is the widespread hard tick Ixodes ricinus, which also transmits the relapsing fever spirochete B. miyamotoi as well as pathogenic Rickettsiales (Anaplasma phagocytophilum, Rickettsia spp.). To assess the public health risk, a long-term monitoring of tick infection rates with the named pathogens is indispensable.

METHODS

The present study is the first German 10-year follow-up monitoring of tick infections with Borrelia spp. and co-infections with Rickettsiales. Furthermore, a specific Reverse Line Blot (RLB) protocol for detection of B. miyamotoi and simultaneous differentiation of B. burgdorferi (s.l.) geno-species was established.

RESULTS

Overall, 24.0% (505/2100) of ticks collected in the city of Hanover were infected with Borrelia. In detail, 35.4% (203/573) of adult ticks [38.5% females (111/288) and 32.3% males (92/285)] and 19.8% nymphs (302/1527) were infected, representing consistent infection rates over the 10-year monitoring period. Geno-species differentiation using RLB determined B. miyamotoi in 8.9% (45/505) of positive ticks. Furthermore, a significant decrease in B. afzelii and B. spielmanii infection rates from 2010 to 2015 was observed. Co-infections with Rickettsia spp. and A. phagocytophilum increased between 2010 and 2015 (7.3 vs 10.9% and 0.3 vs 1.1%, respectively).

CONCLUSIONS

Long-term monitoring is an essential part of public health risk assessment to capture data on pathogen occurrence over time. Such data will reveal shifts in pathogen geno-species distribution and help to answer the question whether or not climate change influences tick-borne pathogens.

First detection of Borrelia miyamotoi in Ixodes ricinus ticks from northern Italy

BACKGROUND

Borrelia miyamotoi is a spirochete transmitted by several ixodid tick species. It causes a relapsing fever in humans and is currently considered as an emerging pathogen. In Europe, B. miyamotoi seems to occur at low prevalence in Ixodes ricinus ticks but has a wide distribution. Here we report the first detection of B. miyamotoi in Ixodes ricinus ticks collected in two independent studies conducted in 2016 in the north-eastern and north-western Alps, Italy.

RESULTS

Three out of 405 nymphs (0.74%) tested positive for Borrelia miyamotoi. In particular, B. miyamotoi was found in 2/365 nymphs in the western and in 1/40 nymphs in the eastern alpine area. These are the first findings of B. miyamotoi in Italy.

CONCLUSIONS

Exposure to B. miyamotoi and risk of human infection may occur through tick bites in northern Italy. Relapsing fever caused by Borrelia miyamotoi has not yet been reported in Italy, but misdiagnoses with tick-borne encephalitis, human granulocytic anaplasmosis or other relapsing fever can occur. Our findings suggest that B. miyamotoi should be considered in the differential diagnosis of febrile patients originating from Lyme borreliosis endemic regions. The distribution of this pathogen and its relevance to public health need further investigation.

Serodiagnosis of Borrelia miyamotoi disease by measuring antibodies against GlpQ and variable major proteins

OBJECTIVES

Borrelia miyamotoi disease (BMD) is an emerging tick-borne disease in the Northern hemisphere. Serodiagnosis by measuring antibodies against glycerophosphodiester-phosphodiesterase (GlpQ) has been performed experimentally but has not been extensively clinically validated. Because we had previously shown the differential expression of antigenic variable major proteins (Vmps) in B. miyamotoi, our aim was to study antibody responses against GlpQ and Vmps in PCR-proven BMD patients and controls.

METHODS

We assessed seroreactivity against GlpQ and four Vmps in a well-described, longitudinal cohort of sera from BMD patients (n=182), healthy blood donors (n=136) and controls (n=68). All samples were tested by ELISA and positive sera were tested by western blot, and antibody dynamics and diagnostic value were assessed.

RESULTS

IgM antibodies against GlpQ and Vmps peaked between 11 and 20 days, and IgG between 21 and 50 days, after disease onset. Various combinations of GlpQ and Vmps increased sensitivity and/or specificity compared to single antigens. Notably, the GlpQ or variable large protein (Vlp)-15/16 combination yielded a sensitivity of 94.7% (95% CI: 75.4-99.7) 11-20 days after disease onset and a specificity of 96.6% (92.7-98.4) for IgM. A specificity of 100% (97.8-100) for IgM, and 98.3% for IgG (95.2-100), was found when positivity was defined as reactivity to GlpQ and any Vmp, with maximum sensitivities of 79% (56.7-91.5) for IgM and 86.7% (62.1-97.6) for IgG.

CONCLUSIONS

We clearly demonstrate here the diagnostic potential of these seromarkers. Our findings will facilitate future epidemiological and clinical studies on BMD and lead to the development of a serologic test to be used in clinical practice.

A multiplex serologic platform for diagnosis of tick-borne diseases

Tick-borne diseases are the most common vector-borne diseases in the United States, with serology being the primary method of diagnosis. We developed the first multiplex, array-based assay for serodiagnosis of tick-borne diseases called the TBD-Serochip. The TBD-Serochip was designed to discriminate antibody responses to 8 major tick-borne pathogens present in the United States, including Anaplasma phagocytophilum, Babesia microti, Borrelia burgdorferi, Borrelia miyamotoi, Ehrlichia chaffeensis, Rickettsia rickettsii, Heartland virus and Powassan virus. Each assay contains approximately 170,000 12-mer linear peptides that tile along the protein sequence of the major antigens from each agent with 11 amino acid overlap. This permits accurate identification of a wide range of specific immunodominant IgG and IgM epitopes that can then be used to enhance diagnostic accuracy and integrate differential diagnosis into a single assay. To test the performance of the TBD-Serochip, we examined sera from patients with confirmed Lyme disease, babesiosis, anaplasmosis, and Powassan virus disease. We identified a wide range of specific discriminatory epitopes that facilitated accurate diagnosis of each disease. We also identified previously undiagnosed infections. Our results indicate that the TBD-Serochip is a promising tool for a differential diagnosis not available with currently employed serologic assays for TBDs.

Transmission of Borrelia miyamotoi sensu lato relapsing fever group spirochetes in relation to duration of attachment by Ixodes scapularis nymphs

Borrelia miyamotoi sensu lato relapsing fever group spirochetes are emerging as causative agents of human illness (Borrelia miyamotoi disease) in the United States. Host-seeking Ixodes scapularis ticks are naturally infected with these spirochetes in the eastern United States and experimentally capable of transmitting B. miyamotoi. However, the duration of time required from tick attachment to spirochete transmission has yet to be determined. We therefore conducted a study to assess spirochete transmission by single transovarially infected I. scapularis nymphs to outbred white mice at three time points post-attachment (24, 48, and 72h) and for a complete feed (>72-96h). Based on detection of B. miyamotoi DNA from the blood of mice fed on by an infected nymph, the probability of spirochete transmission increased from 10% by 24h of attachment (evidence of infection in 3/30 mice) to 31% by 48h (11/35 mice), 63% by 72h (22/35 mice), and 73% for a complete feed (22/30 mice). We conclude that (i) single I. scapularis nymphs effectively transmit B. miyamotoi relapsing fever group spirochetes while feeding, (ii) transmission can occur within the first 24h of nymphal attachment, and (iii) the probability of transmission increases with the duration of nymphal attachment.

Evaluation of a serological test for the diagnosis of Borrelia miyamotoi disease in Europe

BACKGROUND

Borrelia miyamotoi causes systemic febrile illness and is transmitted by the same tick species that transmits Borrelia burgdorferi sensu lato and tick-borne encephalitis virus. We describe a serological test using a fragment of glycerophosphodiester phosphodiesterase (GlpQ) as an antigen, and determined its performance in well-defined patient categories.

METHODS

Serum of patients with PCR-confirmed Borrelia miyamotoi disease (BMD), Lyme borreliosis (LB), tick-borne encephalitis (TBE), and healthy blood donors (HBD) were collected in Udmurt Republic, Russia. Sera of BMD and LB patients were collected at hospital admission, one week, one month and one year after admission.

RESULTS

The levels of IgM and IgG anti-GlpQ antibodies, determined as optical density values in Luminex bead-based assays, were significantly higher in the BMD patient group than in LB patients, TBE patients or HBD group (all p<0.05).

CONCLUSIONS

By using a strict cut-off value, it was possible to exclude B. miyamotoi infection in LB and TBE patients and to serologically confirm B. miyamotoi infection in 44% to 94% of the PCR-positive BMD patients (95% confidence interval). Thus, sensitive serological assays should not solely rely on rGlpQ, to support the diagnosis of acute BMD.

Detection of Borrelia miyamotoi and other tick-borne pathogens in human clinical specimens and Ixodes scapularis ticks in New York State, 2012-2015

Borrelia miyamotoi (Bm) is a recently emerging bacterial agent transmitted by several species of ixodid ticks. Diagnosis of Bm infection can be challenging, as the organism is not easily cultivable. We have developed and validated a multiplex real-time PCR to simultaneously identify Bm infection and the agents causing human granulocytic anaplasmosis and human monocytic ehrlichiosis, Anaplasma phagocytophilum and Ehrlichia chaffeensis, respectively. The assay is 100% specific; highly sensitive, detecting 11 gene copies of Bm DNA in both whole blood and cerebral spinal fluid; and provides rapid results in less than two hours. A retrospective study of 796 clinical specimens collected between the years 2012 and 2014 and a prospective study of 366 clinical specimens were performed utilizing this novel assay to evaluate the frequency of Bm infection in New York State (NYS). Eight clinical specimens (1%) were found to be positive for Bm, 216 were positive for A. phagocytophilum, and 10 were positive for E. chaffeensis. Additionally, we tested 411 I. scapularis ticks collected in NYS during 2013 and 2014 in a separate multiplex real-time PCR to determine the prevalence of Bm, A. phagocytophilum, Borrelia burgdorferi s.s., and Borrelia species. Our results indicated rates of 1.5%, 27%, 19.7%, and 8.8% respectively. The ability to monitor both the frequency and geographic distribution of Bm cases and the prevalence and geographic distribution of Bm in ticks will help create a better understanding of this emerging tick-borne pathogen.

Borrelia miyamotoi in vectors and hosts in The Netherlands

Ixodes ticks transmit Borrelia burgdorferi sensu lato (s.l.), the causative agent of Lyme borreliosis (LB). These tick species also transmit Borrelia miyamotoi, which was recently found to cause infections in humans. We were interested in the prevalence of B. miyamotoi infection in ticks and natural hosts in The Netherlands, and to what extent ticks are co-infected with B. burgdorferi. In addition, erythema migrans has been sporadically described in B. miyamotoi-infected patients, but these skin lesions might as well represent co-infections with B. burgdorferi s.l. We therefore investigated whether B. miyamotoi was present in LB-suspected skin lesions of patients referred to our tertiary Lyme disease clinic. 3360 questing Ixodes ricinus nymphs as well as spleen tissue of 74 rodents, 26 birds and 10 deer were tested by PCR for the presence of B. miyamotoi. Tick lysates were also tested for the presence of B. burgdorferi s.l. Next, we performed a PCR for B. miyamotoi in 31 biopsies from LB-suspected skin lesions in patients visiting our tertiary Lyme center. These biopsies had been initially tested for B. burgdorferi s.l. by PCR, and the skin lesions had been investigated by specialized dermatologists. Out of 3360 unfed (or questing) nymphs, 313 (9.3%) were infected with B. burgdorferi s.l., 70 (2.1%) were infected with B. miyamotoi, and 14 (0.4%) were co-infected with B. burgdorferi s.l. and B. miyamotoi. Co-infection of B. burgdorferi s.l. with B. miyamotoi occurred more often than expected from single infection prevalences (p=0.03). Both rodents (9%) and birds (8%) were found positive for B. miyamotoi by PCR, whereas the roe deer samples were negative. Out of 31 LB-suspected skin biopsies, 10 (32%) were positive for B. burgdorferi s.l. while none were positive for B. miyamotoi. The significant association of B. burgdorferi s.l. with B. miyamotoi in nymphs implies the existence of mutual reservoir hosts. Indeed, the presence of B. miyamotoi DNA indicates systemic infections in birds as well as rodents. However, their relative contributions to the enzootic cycle of B. miyamotoi requires further investigation. We could not retrospectively diagnose B. miyamotoi infection using biopsies of LB-suspected skin lesions, supporting the hypothesis that B. miyamotoi is not associated with LB-associated skin manifestations. However, this warrants further studies in larger sets of skin biopsies. A prospective study focused on acute febrile illness after a tick bite could provide insight into the incidence and clinical manifestations of B. miyamotoi infection in The Netherlands.

Hard Tick Relapsing Fever Caused by Borrelia miyamotoi in a Child

A 5-year-old Massachusetts resident developed hard tick-borne relapsing fever caused by Borrelia miyamotoi. A partially engorged Ixodes scapularis tick was removed from her scalp and identified as infected with B. miyamotoi using polymerase chain reaction. Two weeks later, she developed an illness compatible with B. miyamotoi infection that included fatigue and recurrent fever. The diagnosis was confirmed by B. miyamotoi seroconversion.

Molecular Detection of Tick-Borne Pathogens in Humans with Tick Bites and Erythema Migrans, in the Netherlands

BACKGROUND

Tick-borne diseases are the most prevalent vector-borne diseases in Europe. Knowledge on the incidence and clinical presentation of other tick-borne diseases than Lyme borreliosis and tick-borne encephalitis is minimal, despite the high human exposure to these pathogens through tick bites. Using molecular detection techniques, the frequency of tick-borne infections after exposure through tick bites was estimated.

METHODS

Ticks, blood samples and questionnaires on health status were collected from patients that visited their general practitioner with a tick bite or erythema migrans in 2007 and 2008. The presence of several tick-borne pathogens in 314 ticks and 626 blood samples of this cohort were analyzed using PCR-based methods. Using multivariate logistic regression, associations were explored between pathogens detected in blood and self-reported symptoms at enrolment and during a three-month follow-up period.

RESULTS

Half of the ticks removed from humans tested positive for Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Candidatus Neoehrlichia mikurensis, Rickettsia helvetica, Rickettsia monacensis, Borrelia miyamotoi and several Babesia species. Among 92 Borrelia burgdorferi s. l. positive ticks, 33% carried another pathogen from a different genus. In blood of sixteen out of 626 persons with tick bites or erythema migrans, DNA was detected from Candidatus Neoehrlichia mikurensis (n = 7), Anaplasma phagocytophilum (n = 5), Babesia divergens (n = 3), Borrelia miyamotoi (n = 1) and Borrelia burgdorferi s. l. (n = 1). None of these sixteen individuals reported any overt symptoms that would indicate a corresponding illness during the three-month follow-up period. No associations were found between the presence of pathogen DNA in blood and; self-reported symptoms, with pathogen DNA in the corresponding ticks (n = 8), reported tick attachment duration, tick engorgement, or antibiotic treatment at enrolment.

CONCLUSIONS

Based on molecular detection techniques, the probability of infection with a tick-borne pathogen other than Lyme spirochetes after a tick bite is roughly 2.4%, in the Netherlands. Similarly, among patients with erythema migrans, the probability of a co-infection with another tick-borne pathogen is approximately 2.7%. How often these infections cause disease symptoms or to what extend co-infections affect the course of Lyme borreliosis needs further investigations.

Borrelia miyamotoi: A human tick-borne relapsing fever spirochete in Europe and its potential impact on public health

Borrelia miyamotoi is a tick-borne bacterium which has only recently been identified in Europe as a human pathogen causing relapsing fever and little is known about its local impact on human health. There are three types of B. miyamotoi: Asian (Siberian), European, and American. B. miyamotoi is transmitted by the same Ixodes ricinus-persulcatus species complex, which also transmits B. burgdorferi s.l., the Lyme borreliosis group. Both Borrelia groups are mostly maintained in natural rodent populations. The aim of this review is to summarize the available literature on B. miyamotoi, with the focus of attention falling on Europe, as well as to describe its presence in ticks, reservoir hosts, and humans and discuss its potential impact on public health.

Variable Major Proteins as Targets for Specific Antibodies against Borrelia miyamotoi

Borrelia miyamotoi is a relapsing fever spirochete in Ixodes ticks that has been recently identified as a human pathogen causing hard tick-borne relapsing fever (HTBRF) across the Northern Hemisphere. No validated serologic test exists, and current serologic assays have low sensitivity in early HTBRF. To examine the humoral immune response against B. miyamotoi, we infected C3H/HeN mice with B. miyamotoi strain LB-2001 expressing variable small protein 1 (Vsp1) and demonstrated that spirochetemia was cleared after 3 d, coinciding with anti-Vsp1 IgM production. Clearance was also observed after passive transfer of immune sera to infected SCID mice. Next, we showed that anti-Vsp1 IgG eliminates Vsp1-expressing B. miyamotoi, selecting for spirochetes expressing a variable large protein (VlpC2) resistant to anti-Vsp1. The viability of Asian isolate B. miyamotoi HT31, expressing Vlp15/16 and Vlp18, was also unaffected by anti-Vsp1. Finally, in nine HTBRF patients, we demonstrated IgM reactivity to Vsp1 in two and against Vlp15/16 in four ∼1 wk after these patients tested positive for B. miyamotoi by PCR. Our data show that B. miyamotoi is able to express various variable major proteins (VMPs) to evade humoral immunity and that VMPs are antigenic in humans. We propose that serologic tests based on VMPs are of additional value in diagnosing HTBRF.

Molecular identification of Borrelia genus in questing hard ticks from Portugal: Phylogenetic characterization of two novel Relapsing Fever-like Borrelia sp

In the last decades, several studies have reported pathogenic species of Borrelia related to those that cause Tick-borne Relapsing Fever (RF), but unexpectedly suggesting their transmission by hard ticks, known vectors of Borrelia burgdorferi sensu lato (B. burgdorferi s.l.) species, rather than by soft ticks. This study was designed to update the presence of B. burgdorferi s.l. species in ticks from several districts of mainland Portugal, where Ixodes ricinus had been previously described. Ticks (a total of 2915 specimens) were collected in seven districts throughout the country, and analyzed using molecular methods. Three nested-PCR protocols, targeting the flagellin gene (flaB), the intergenic spacer region (IGS) located between 5S and 23S rRNA, and the glpQ gene, and a conventional PCR targeting the 16S rRNA, were used for Borrelia DNA detection. Borrelia DNA was detected in 3% of the ticks from Braga, Vila Real, Lisboa, Setúbal, Évora and Faro districts. The obtained amplicons were sequenced and analyzed by BLASTn, and 15/63 (24%) matched with homologous sequences from Borrelia lusitaniae and 15/63 (24%) with B. garinii, being these the most prevalent species. DNA from B. burgdorferi sensu stricto (s.s.), B. valaisiana and B. afzelii were detected in 7/63 (11%), 6/63 (10%), and 2/63 (3%) of the specimens, respectively. Unexpectedly, DNA sequence (flaB) analysis from eight (13%) samples, two from Rhipicephalus sanguineus and six from Haemaphysalis punctata tick species, revealed high homology with RF-like Borrelia. Phylogenetic analyses obtained from three genetic markers (16S rRNA, flaB, and glpQ) confirmed their congruent inclusion in a strongly supported RF cluster, where they segregated in two subgroups which differ from the other Relapsing Fever species. Therefore, the results confirm the circulation of multiple species of B. burgdorferi s.l. over a wide geographic range, covering most of the Portuguese mainland territory. Surprisingly, the obtained data also revealed two putative Relapsing Fever-like Borrelia species in different species of hard ticks, possibly disclosing the circulation of novel RF-like Borrelia species with different associated tick vectors.

[Relapsing (recurrent) disease caused by Borrelia miyamotoi]

AIM

To clarify the clinical, laboratory, and epidemiological characteristics of relapsing Ixodes tick-borne borreliosis (ITB) caused by Borrelia miyamotoi.

SUBJECTS AND METHODS

Retrospective clinical observation was made in 79 inpatients of the Republican Infectious Diseases Hospital (Udmurt Republic), who had been diagnosed with B. miyamotoi-caused disease verified by real-time polymerase chain reaction. The latter and enzyme immunoassay ruled out possible vector-borne coinfections (ITB caused by B. burgdorferi sensu lato; tick-borne encephalitis; anaplasmosis; and ehrlichiosis).

RESULTS

The recurrent course of the disease was observed in 8 (10%) of the 79 patients. The relapsing fever curve was noted in 6 of the 8 patients; 4 patients had 2 episodes of fever and 2 patients had 3 episodes; the wave-like continuous type of fever cannot enable one to estimate the specific number of episodes in 2 more cases. Relapses occurred in all the 8 patients before antibiotic treatment. Febrile syndrome (weakness, headache, chill, fever, sweating, dizziness, nausea, vomiting, myalgia, and arthralgia) was leading in patients with relapses. These patients were less frequently observed to have signs of organ dysfunctions than those with one episode of fever. The values of clinical and biochemical blood tests and urinalyses were normal and near-normal in the majority of patients on hospital admission.

CONCLUSION

Relapsing B. miyamotoi infection cases detected in the directed study proved to be unrecognized by practical health authorities during the first and sometimes second episodes of fever. This indicates that the prevalence of this disease is essentially underestimated and there is a need to increase physicians' alertness and awareness and to introduce adequate diagnostic methods.

[The blood coagulation system and microcirculatory disorders in ixodid tick-borne borreliosis caused by Borrelia miyamotoi]

AIM

To study blood coagulation and microcirculatory disorders as a possible cause of transient dysfunctions of organs (the kidney, liver, heart, lung, etc.) in patients with ixodid tick-borne borreliosis caused by Borrelia miyamotoi (Bmt). SUBJECTS AND METHODS; Twenty-four patients with Lyme disease (LD) and 28 Bmt patients treated at Izhevsk City Hospital (Udmurtia) were examined in the study. Platelet counts and the presence of D-dimers were determined; activated partial thromboplastin time, prothrombin time, thrombin time, fibrinogen and antithrombin III levels, and Factor XIIa-dependent fibrin clot lysis time were measured. Slit lamp microscopy of the conjunctiva was. also carried out. Results. Platelet counts'were less than 150,000 per pL of blood in 43% of the Bmt patients. All the Bmt patients had at least one abnormal coagulation parameter of the eight ones that were tested; 64% of them had marked coagulation disorders with three or more abnormal laboratory findings. In contrast, all the eight parameters were normal in 71% of the LD patients. The other seven LD patients had only one or two abnormal coagulation parameters (p < 0.001 in comparison with Bmt patients). Microscopic examination of eye capillary blood flow revealed pathological findings that included aggregates of erythrocytes and obstructed and/or sinuous capillaries in 22 (79%) of the Bmt patients, but none of the LD patients. A total of 14 Bmt patients had both coagulation and microcirculatory abnormalities. Eleven of them also had transient signs of organ dysfunction.

CONCLUSION

As far as Borrelia secrete no known toxins, we hypothesized that uncovered disorders of blood coagulation and microcirculation in Bmt patients may contribute to organ dysfunction.

Eco-epidemiology of Borrelia miyamotoi and Lyme borreliosis spirochetes in a popular hunting and recreational forest area in Hungary

Background

Borrelia miyamotoi, the newly discovered human pathogenic relapsing fever spirochete, and Borrelia burgdorferi sensu lato are maintained in natural rodent populations. The aim of this study was to investigate the natural cycle of B. miyamotoi and B. burgdorferi s.l. in a forest habitat with intensive hunting, forestry work and recreational activity in Southern Hungary.

Methods

We collected rodents with modified Sherman-traps during 2010–2013 and questing ticks with flagging in 2012. Small mammals were euthanized, tissue samples were collected and all ectoparasites were removed and stored. Samples were screened for pathogens with multiplex quantitative real-time polymerase chain reaction (qPCR) targeting a part of flagellin gene, then analysed with conventional PCRs and sequencing.

Results

177 spleen and 348 skin samples of six rodent species were individually analysed. Prevalence in rodent tissue samples was 0.2 % (skin) and 0.5 % (spleen) for B. miyamotoi and 6.6 % (skin) and 2.2 % (spleen) for B. burgdorferi s.l. Relapsing fever spirochetes were detected in Apodemus flavicollis males, B. burgdorferi s.l. in Apodemus spp. and Myodes glareolus samples. Borrelia miyamotoi was detected in one questing Ixodes ricinus nymph and B. burgdorferi s.l in nymphs and adults. In the ticks removed from rodents DNA amplification of both pathogens was successful from I. ricinus larvae (B. miyamotoi 5.6 %, B. burgdorferi s.l. 11.1 %) and one out of five nymphs while from Ixodes acuminatus larvae, and nymph only B. burgdorferi s.l. DNA was amplified. Sequencing revealed B. lusitaniae in a questing I. ricinus nymph and altogether 17 B. afzelii were identified in other samples. Two Dermacentor marginatus engorged larva pools originating from uninfected hosts were also infected with B. afzelii.

Conclusions

This is the first report of B. miyamotoi occurrence in a natural population of A. flavicollis as well as in Hungary. We provide new data about circulation of B. burgdorferi s.l. in rodent and tick communities including the role of I. acuminatus ticks in the endophilic pathogen cycle. Our results highlight the possible risk of infection with relapsing fever and Lyme borreliosis spirochetes in forest habitats especially in the high-risk groups of hunters, forestry workers and hikers.

Borrelia miyamotoi: a widespread tick-borne relapsing fever spirochete

Borrelia miyamotoi is a relapsing fever spirochete that has only recently been identified as a human pathogen. Borrelia miyamotoi is genetically and ecologically distinct from Borrelia burgdorferi sensu lato, while both are present in Ixodes ticks. Over 50 patients with an acute febrile illness have been described with a B. miyamotoi infection, and two infected immunocompromised patients developed a meningoencephalitis. Seroprevalence studies indicate exposure in the general population and in specific risk groups, such as patients initially suspected of having human granulocytic anaplasmosis. Here, we review the available literature on B. miyamotoi, describing its presence in ticks, reservoir hosts, and humans, and discussing its potential impact on public health.

Borrelia miyamotoi infection in nature and in humans

Borrelia miyamotoi is a relapsing fever Borrelia group spirochete that is transmitted by the same hard-bodied (ixodid) tick species that transmit the agents of Lyme disease. It was discovered in 1994 in Ixodes persulcatus ticks in Japan. B. miyamotoi species phylogenetically cluster with the relapsing fever group spirochetes, which usually are transmitted by soft-bodied (argasid) ticks or lice. B. miyamotoi infects at least six Ixodes tick species in North America and Eurasia that transmit Lyme disease group spirochetes and may use small rodents and birds as reservoirs. Human cases of B. miyamotoi infection were first reported in 2011 in Russia and subsequently in the United States, Europe and Japan. These reports document the public health importance of B. miyamotoi, as human B. miyamotoi infection appears to be comparable in frequency to babesiosis or human granulocytic anaplasmosis in some areas and may cause severe disease, including meningoencephalitis. The most common clinical manifestations of B. miyamotoi infection are fever, fatigue, headache, chills, myalgia, arthralgia, and nausea. Symptoms of B. miyamotoi infection generally resolve within a week of the start of antibiotic therapy. B. miyamotoi infection should be considered in patients with acute febrile illness who have been exposed to Ixodes ticks in a region where Lyme disease occurs. Because clinical manifestations are nonspecific, etiologic diagnosis requires confirmation by blood smear examination, PCR, antibody assay, in vitro cultivation, and/or isolation by animal inoculation. Antibiotics that have been used effectively include doxycycline for uncomplicated B. miyamotoi infection in adults and ceftriaxone or penicillin G for meningoencephalitis.