Common Tick-borne Disease Research Articles

Tick-Borne Diseases: Identification, Management and Prevention

Tick borne diseases have become a public health crisis in endemic areas of the world. It is important for health care professionals to be aware of the clinical manifestations of tick borne diseases, and recommended practices for their diagnosis and treatment. It is also important to educate the public on signs of disease and how to mitigate exposure. An understanding about the life cycle of ticks and the interplay of the environment is also crucial to reduce morbidity and mortality. This article presents the most common tick borne diseases of hard bodied ticks in the United States which are transmitted by: deer tick: Ixodes scapularis and pacificus, dog tick: Amblyomma americium and lone star tick: Dermacentor variabilis. Diseases from infected ticks (bacterial, parasitic and viral) include Lyme disease, babesiosis, anaplasmosis, ehrlichiosis, tularemia, Powassan virus (POW virus) and Southern Tick Associated Rash Illness (STARI). There is increasing concern with new and emerging strains of other tick borne diseases such as Borrelia miyamotoi.

Lyme Disease and YouTube TM: A Cross-Sectional Study of Video Contents.

ObjectivesLyme disease is the most common tick-borne disease. People seek health information on Lyme disease from YouTubeTM videos. In this study, we investigated if the contents of Lyme disease-related YouTubeTM videos varied by their sources.MethodsMost viewed English YouTubeTM videos (n = 100) were identified and manually coded for contents and sources.ResultsWithin the sample, 40 videos were consumer-generated, 31 were internet-based news, 16 were professional, and 13 were TV news. Compared with consumer-generated videos, TV news videos were more likely to mention celebrities (odds ratio [OR], 10.57; 95% confidence interval [CI], 2.13–52.58), prevention of Lyme disease through wearing protective clothing (OR, 5.63; 95% CI, 1.23–25.76), and spraying insecticides (OR, 7.71; 95% CI, 1.52–39.05).ConclusionA majority of the most popular Lyme disease-related YouTubeTM videos were not created by public health professionals. Responsible reporting and creative video-making facilitate Lyme disease education. Partnership with YouTubeTM celebrities to co-develop educational videos may be a future direction.

Infection of Ixodes ricinus by Borrelia burgdorferi sensu lato in peri-urban forests of France.

Lyme borreliosis is the most common tick-borne disease in the northern hemisphere. In Europe, it is transmitted by Ixodes ticks that carry bacteria belonging to the Borrelia burgdorferi sensu lato complex. The objective of this work was to explore eco-epidemiological factors of Lyme borreliosis in peri-urban forests of France (Sénart, Notre-Dame and Rambouillet). We investigated whether the introduction of Tamias sibiricus in Sénart could alter the density of infected ticks. Moreover, the density and tick infection were investigated according to the tree species found in various patches of Sénart forest. For this purpose, ticks were sampled during 3 years. In the Sénart forest, the density of nymph and adult ticks showed no significant difference between 2008, 2009 and 2011. The nymph density varied significantly as a function of the month of collection. Regarding the nymphs, a higher rate of infection and infected density were found in 2009. Plots with chipmunks (C) presented a lower density of both nymphs and adult ticks than plots without chipmunks (NC) did. A higher rate of infection of nymphs with Borrelia was seen in C plots. The prevalence of the various species of Borrelia was also found to vary between C and NC plots with the year of the collect. The presence of chestnut trees positively influenced the density of both nymphs and adults. The infected nymph density showed a significant difference depending on the peri-urban forest studied, Sénart being higher than Rambouillet. The prevalence of Borrelia species also differed between the various forests studied. Concerning the putative role that Tamias sibiricus may play in the transmission of Borrelia, our results suggest that its presence is correlated with a higher rate of infection of questing ticks by Borrelia genospecies and if its population increases, it could play a significant role in the risk of transmission of Lyme borreliosis.

Antibody fingerprints in lyme disease deciphered with high density peptide arrays.

Lyme disease is the most common tick-borne infectious disease in Europe and North America. Previous studies discovered the immunogenic role of a surface-exposed lipoprotein (VlsE) of Borreliella burgdorferi. We employed high density peptide arrays to investigate the antibody response to the VlsE protein in VlsE-positive patients by mapping the protein as overlapping peptides and subsequent in-depth epitope substitution analyses. These investigations led to the identification of antibody fingerprints represented by a number of key residues that are indispensable for the binding of the respective antibody. This approach allows us to compare the antibody specificities of different patients to the resolution of single amino acids. Our study revealed that the sera of VlsE-positive patients recognize different epitopes on the protein. Remarkably, in those cases where the same epitope is targeted, the antibody fingerprint is almost identical. Furthermore, we could correlate two fingerprints with human autoantigens and an Epstein-Barr virus epitope; yet, the link to autoimmune disorders seems unlikely and must be investigated in further studies. The other three fingerprints are much more specific for B. burgdorferi. Since antibody fingerprints of longer sequences have proven to be highly disease specific, our findings suggest that the fingerprints could function as diagnostic markers that can reduce false positive test results.

Investigation of A Potential Relationship Between Wild Bird Populations and Human Lyme Disease Rate in Connecticut from 1991-2002

مرض لايم هو أكثر الأمراض المنقولة بالقراد شيوعًا في أمريكا الشمالية. بوريليا برغدورفيرية ، هو العامل الممرض ، والقراد ذو الأرجل السوداء يحمل البكتيريا وينشرها عندما يتغذى على دماء الحيوانات والبشر. يتم تطفل ما لا يقل عن 70 نوعًا من أنواع الجاسرين ونوع واحد من نقار الخشب في أمريكا الشمالية عن طريق القراد غير الناضج ذو الأرجل السوداء. تتنبأ هذه الفرضية بأنه ستكون هناك علاقة إيجابية بين معدلات مرض لايم وأعداد الطيور المصابة بالعوامل الممرضة ، ولن تكون هناك علاقة بين معدل مرض لايم وأعداد الطيور غير المعروفة بأنها مصابة بالممرض. لقد اعتمدت على مسح أمريكا الشمالية لتربية الطيور (BBS) للحصول على أنواع الطيور لـ 14 طريقًا عبر ولاية كونيتيكت ، وفي ولاية كونيتيكت DHS للحصول على معدلات مرض لايم للفترة الزمنية للدراسة (1991-2002). كانت بيانات طائرتي هي: مجموعة واحدة تضمنت جميع أنواع الطيور السبعة عشر التي تحمل العامل الممرض ، ونوعين منفصلين يُعرفان بإصابتهما بالعدوى من قبل ممرض لايم (روبن الأمريكي وغراي كاتبيرد) ، وأنواع ضابطة غير معروفة بأنها تحمل العامل الممرض (الأمريكي). ريدستارت). لقد وجدت علاقات إيجابية كبيرة بين أعداد الطيور ومعدل مرض لايم البشري في مسارين لمجموعة SCLP ، مسار واحد لروبن الأمريكي ، وثلاثة مسارات للطائر الرمادي المواء Catbird ، وطريقان لـ حميراء أمريكية American Redstart. فقط غراي كاتبيرد كان له علاقة سلبية مع معدل مرض لايم البشري في طريق واحد. بناءً على العلاقات الإيجابية التي ظهرت لدى طائر حميراء أمريكية ، والأنواع الضابطة ، والعلاقات القليلة المهمة للطيور المعروف أنها تحمل العامل الممرض ، أرفض الفرضية القائلة بوجود علاقة قوية بين أعداد الطيور التي يمكن أن تكون مصابة ببكتيريا B. ومعدل الإصابة بمرض لايم عند الأشخاص كما تم قياسه بالطرق المستخدمة في هذه الدراسة.

Investigating the Adult Ixodid Tick Populations and Their Associated Anaplasma, Ehrlichia, and Rickettsia Bacteria at a Rocky Mountain Spotted Fever Hotspot in Western Tennessee.

Ehrlichiosis and rickettsiosis are two common bacterial tick-borne diseases in the southeastern United States. Ehrlichiosis is caused by ehrlichiae transmitted by Amblyomma americanum and rickettsiosis is caused by rickettsiae transmitted by Amblyomma maculatum and Dermacentor variabilis. These ticks are common and have overlapping distributions in the region. The objective of this study was to identify Anaplasma, Ehrlichia, and Rickettsia species associated with questing ticks in a Rocky Mountain spotted fever (RMSF) hotspot, and identify habitats, time periods, and collection methods for collecting questing-infected ticks. Using vegetation drags and CO2-baited traps, ticks were collected six times (May-September 2012) from 100 sites (upland deciduous, bottomland deciduous, grassland, and coniferous habitats) in western Tennessee. Adult collections were screened for Anaplasma and Ehrlichia (simultaneous polymerase chain reaction [PCR]) and Rickettsia using genus-specific PCRs, and resulting positive amplicons were sequenced. Anaplasma and Ehrlichia were only identified within A. americanum (Ehrlichia ewingii, Ehrlichia chaffeensis, Panola Mountain Ehrlichia, and Anaplasma odocoilei sp. nov.); more Ehrlichia-infected A. americanum were collected at the end of June regardless of habitat and collection method. Rickettsia was identified in three tick species; "Candidatus Rickettsia amblyommii" from A. americanum, R. parkeri and R. andeanae from A. maculatum, and R. montanensis ( = montana) from D. variabilis. Overall, significantly more Rickettsia-infected ticks were identified as A. americanum and A. maculatum compared to D. variabilis; more infected-ticks were collected from sites May-July and with dragging. In this study, we report in the Tennessee RMSF hotspot the following: (1) Anaplasma and Ehrlichia are only found in A. americanum, (2) each tick species has its own Rickettsia species, (3) a majority of questing-infected ticks are collected May-July, (4) A. americanum and A. maculatum harbor pathogenic bacteria in western Tennessee, and (5) R. rickettsii remains unidentified.

Candidatus Neoehrlichia mikurensis and Borrelia burgdorferi sensu lato detected in the blood of Norwegian patients with erythema migrans

The most common tick-borne human disease in Norway is Lyme borreliosis. Ticks in Norway also harbour less known disease-causing agents such as Candidatus Neoehrlichia mikurensis, Borrelia miyamotoi and Rickettsia helvetica. However, human infections caused by these pathogens have never been described in Norway. The main aims of the study were to evaluate the contribution of several tick-borne bacterial agents, other than Borrelia burgdorferi sensu lato, to zoonotic diseases in Norway and to determine their clinical pictures.Blood samples from 70 symptomatic tick-bitten adults from the Agder counties in southern Norway were screened for seven tick-borne pathogens by using a commercial multiplex PCR-based method and by singleplex real-time PCR protocols. Most patients (65/70) presented with a rash clinically diagnosed as erythema migrans (EM). The most frequently detected pathogen DNA was from Ca. N. mikurensis and was found in the blood of 10% (7/70) of the patients. The Ca. N. mikurensis-infected patients presented with an EM-like rash as the only symptom. B. burgdorferi s.l. DNA was present in the blood of 4% (3/70) of the study participants. None had detectable Anaplasma phagocytophilum, B. miyamotoi, Rickettsia typhus group or spotted fever group, Francisella tularensis, Coxiella burnetii or Bartonella spp. DNA in the blood.The commercially available multiplex PCR bacteria flow chip system failed to identify half of the infected patients detected by corresponding real-time PCR protocols. The recovery of Ca. N. mikurensis DNA was higher in the pellet/plasma fraction of blood than from whole blood. To conclude, Ca. N. mikurensis appeared to be the etiological agent in patients with EM in a surprisingly large fraction of tick-bitten persons in the southern part of Norway.

Lyme disease ecology in a changing world: consensus, uncertainty and critical gaps for improving control.

Lyme disease is the most common tick-borne disease in temperate regions of North America, Europe and Asia, and the number of reported cases has increased in many regions as landscapes have been altered. Although there has been extensive work on the ecology and epidemiology of this disease in both Europe and North America, substantial uncertainty exists about fundamental aspects that determine spatial and temporal variation in both disease risk and human incidence, which hamper effective and efficient prevention and control. Here we describe areas of consensus that can be built on, identify areas of uncertainty and outline research needed to fill these gaps to facilitate predictive models of disease risk and the development of novel disease control strategies. Key areas of uncertainty include: (i) the precise influence of deer abundance on tick abundance, (ii) how tick populations are regulated, (iii) assembly of host communities and tick-feeding patterns across different habitats, (iv) reservoir competence of host species, and (v) pathogenicity for humans of different genotypes of Borrelia burgdorferi Filling these knowledge gaps will improve Lyme disease prevention and control and provide general insights into the drivers and dynamics of this emblematic multi-host-vector-borne zoonotic disease.This article is part of the themed issue 'Conservation, biodiversity and infectious disease: scientific evidence and policy implications'.

Tick bite and Lyme disease-related emergency department encounters in New Hampshire, 2010-2014.

Lyme disease (LD) is a common tick-borne disease in New Hampshire (NH). While LD is a reportable condition and cases are counted for public health surveillance, many more people receive care for tick bites or diagnoses of LD than are reflected in surveillance data. NH's emergency department (ED) data system was queried for tick bite and LD-related encounters. Chief complaint text was queried for words related to LD or tick bites. International Classification of Diseases 9th Revision (ICD-9) codes were queried for the LD diagnosis code (088.81). Emergency department patient data were matched to reportable disease data to determine the proportion of ED patients reported to the health department as a suspected LD case. Data were analysed to calculate frequencies for key demographic and reporting characteristics. From 2010 to 2014, 13,615 tick bite or LD-related ED encounters were identified in NH, with most due to tick bites (76%). Of 3,256 patients with a LD-related ED encounter, 738 (23%) were reported to the health department as a suspected LD case. The geographic distribution of ED patients was similar to reported LD cases; however, the regions of the state that experienced higher rates of ED encounters were different than the regions that observed higher rates of reported LD cases. Seasonal distribution of ED encounters peaked earlier than reported LD cases with a second peak in the fall. While age and sex distribution was similar among ED patients and reported LD cases, the rates for children 5years and younger and adults 65years and older were greater for ED encounters. Patients frequently visit the ED to seek care for tick bites and suspected LD. Results of ED data analyses can be used to target education, in particular for ED providers and the public through timely distribution of evidence-based educational materials and training programmes.

Searching for Lyme borreliosis in Australia: results of a canine sentinel study

BackgroundLyme borreliosis is a common tick-borne disease of the northern hemisphere that is caused by bacterial spirochaetes of the Borrelia burgdorferi (sensu lato) (Bbsl) complex. To date, there has been no convincing evidence for locally-acquired Lyme borreliosis on the Australian continent and there is currently a national debate concerning the nature and distributions of zoonotic tick-transmitted infectious disease in Australia. In studies conducted in Europe and the United States, dogs have been used as sentinels for tick-associated illness in people since they readily contact ticks that may harbour zoonotic pathogens. Applying this principle, we used a combination of serological assays to test dogs living in tick ‘hot spots’ and exposed to the Australian paralysis tick, Ixodes holocyclus, for evidence of exposure to B. burgdorferi (s.l.) antigens and other vector-borne pathogens.ResultsAltogether, 555 dogs from four demographic groups were recruited into this study. One dog had evidence of exposure to Anaplasma spp. but no other dog was positive in screening tests. A total of 122 dogs (22.0%) had a kinetic ELISA (KELA) unit value > 100, and one dog with a high titre (399.9 KELA units) had been vaccinated against B. burgdorferi (sensu stricto) before travelling to Australia. Older dogs and those with a history of tick paralysis were significantly more likely to have a KELA unit value > 100. Line immunoassay analysis revealed moderate-to-weak (equivocal) bands in 27 (4.9%) dogs.ConclusionsExcept for a single dog presumed to have been exposed to Anaplasma platys, infection with Anaplasma spp. B. burgdorferi (s.l.), Ehrlichia spp., and Dirofilaria immitis, was not detected in the cohort of Australian dogs evaluated in this study. These results provide further evidence that Lyme borreliosis does not exist in Australia but that cross-reacting antibodies (false positive results) are common and may be caused by the transmission of other tick-associated organisms.

Investigation of a Potential Relationship Between Wild Bird Populations and Human Lyme Disease Rate in Connecticut from 1991-2002

Lyme disease is the most common tick-borne disease in North America. Borrelia burgdorferi, is the pathogen, and the black-legged tick carries the bacteria and spreads it when feeding on the blood of animals and humans. At least 70 passerine species and one species of woodpecker in North American are parasitized by immature black-legged ticks. This hypothesis predicts that there would be a positive relationship between Lyme disease rates and bird numbers that infected with the pathogen, and there would be no relationship between Lyme disease rate and bird numbers that not known to be infected with the pathogen. The study depended on the North American Breeding Bird Survey (BBS) to get bird species for 14 routes across Connecticut, and on the Connecticut DHS to get Lyme disease rates for the time period of the study (1991-2002). The range of years was from 1991 to 2002 because of a change in how Lyme disease cases were reported starting in 2003. The bird data were: one group that included all 17 bird species that carry the pathogen, two species separately that are known to become infected by Lyme pathogen (American Robin and Gray Catbird), and a control species not known to carry the pathogen (American Redstart). The study found significant positive relationships between bird numbers and human Lyme disease rate in two routes for the SCLP group, one route for American Robin, three routes for Gray Catbird, and two routes for American Redstart. Only Gray Catbird had a significant negative relationship with human Lyme disease rate in one route. Based on the positive relationships that appeared for American Redstart, the control species, and the few significant relationships for birds known to carry the pathogen, the study rejected the hypothesis that there is a strong relationship between numbers of birds that could be infected with B. burgdorferi and the rate of Lyme disease in people as measured by the methods used in this study.

Tickborne diseases other than Lyme in the United States.

Tickborne diseases are increasing in the United States, and the geographic range of tick vectors is expanding. Tickborne diseases are challenging to diagnose, as they present with vague symptoms such as fever, constitutional symptoms, and nonspecific laboratory abnormalities. A high degree of clinical suspicion is required to make a diagnosis, as patients often do not recall a tick bite. The availability of laboratory testing for tickborne diseases is limited, especially in the acute setting. Therefore, if a tickborne disease is suspected, empiric therapy should often be initiated before laboratory confirmation of the disease is available. This article summarizes the most common non-Lyme tickborne diseases in the United States.

The eye and tick-borne disease in the United States.

Tick-borne diseases are increasing in incidence and geographic distribution. Several diseases endemic to the United States have ophthalmic manifestations, including the most common tick-borne disease, Lyme borreliosis. As ocular complaints may lead a patient to seek medical evaluation, it is important to be aware of the systemic and ophthalmic manifestations of tick-borne diseases in order to make the correct diagnosis. Vision-threatening ophthalmic manifestations are relatively common in Lyme disease and Rocky Mountain spotted fever. Ocular involvement is rare in babesiosis, tick-borne relapsing fever, Powassan encephalitis, ehrlichiosis, anaplasmosis, and Colorado tick fever.There are clear guidelines for diagnosis and treatment of Lyme disease; however, confusion and misinformation among the general public as well as controversy about chronic or late-stage Lyme disease can impact the evaluation of ophthalmic disease. Furthermore, there are many gaps in our knowledge regarding the pathophysiology of ocular borreliosis although it seems likely that Lyme uveitis is rare in the United States. Knowledge of systemic and ophthalmic manifestations combined with an understanding of the epidemiology of disease vectors is crucial for the diagnosis of tick-borne diseases.

Tick-borne diseases in dogs

Tick-borne diseases (TBDs) can have serious impact on the health and welfare of dogs, and have been described in all continents. The expanding number of tick-borne pathogens, the broad geographic range of many tick species, the ability of tick-borne pathogens to induce infections, and the highly zoonotic potential of some of these pathogens make TBDs the most important subcategory of canine vector-borne infectious diseases worldwide. Indeed, emerging TBDs have become a concern for pet owners and veterinary professionals. The occurrence of babesiosis in a cluster of dogs from Harlow, Essex in 2016 has raised some concerns regarding the inevitable increase in the risk of TBDs particularly after the relaxation of pet travel rules. In addition to babesiosis that has dominated recent headlines other TBDs such as Lyme borreliosis have more quietly expanded to many parts of the country. The large number of tick-borne pathogens, the diversity of tick vectors, the broad range of animal reservoir hosts, limitations associated with diagnosis and treatment, and the ecological complexity of tick-borne pathogens make effective control of TBDs a challenging task. Therefore, it is important for veterinary professionals to be able to detect TBDs early and accurately in order to minimise the morbidity and mortality of these diseases. This article provides an update on some of the most common TBDs in dogs, namely babesiosis, hepatozoonosis, borreliosis, anaplasmosis, and ehrlichiosis. The key roles that veterinary nurses can play to support pet owners in recognising and dealing with ticks and TBDs are also discussed.

Occurrence of Borrelia burgdorferi Sensu Lato in Ixodes ricinus Ticks with First Identification of Borrelia miyamotoi in Vojvodina, Serbia.

Lyme borreliosis is the most common tick-borne infectious disease in Eurasia. Borrelia miyamotoi is the only known relapsing fever Borrelia group spirochete transmitted by Ixodes species. The aim of this study was to investigate the presence of Lyme Borrelia spp. and relapsing fever Borrelia spp. in Ixodes ricinus ticks collected from dogs and the vegetation from different parts of Vojvodina, Serbia. A total of 71 Ixodes ricinus ticks were collected and screened for the presence of Lyme Borrelia spp. group and relapsing fever Borrelia spp. by real-time PCR for the Borrelia flagellin B (flaB) gene followed by DNA sequencing of PCR products. Species identification was verified by PCR of the outer surface protein A (ospA) gene for Lyme Disease Borrelia spp. and by PCR of the glycerophosphodiester phosphodiesterase (glpQ) gene for relapsing fever Borrelia spp. Lyme Borrelia spp. were found in 15/71 (21.13%) of the ticks evaluated and included B. luisitaniae (11.3%), B. afzelii (7%), B. valaisiana (1.4%), and B. garinii (1.4%). Borrelia miyamotoi, from the relapsing fever Borrelia complex, was found, for the first time in Serbia, in one (1.4%) nymph collected from the environment. Co-infections between Borrelia species in ticks were not detected. These results suggest that the dominance of species within B. burgdorferi s.l. complex in I. ricinus ticks may vary over time and in different geographic regions. Further systematic studies of Borrelia species in vectors and reservoir hosts are needed to understand eco-epidemiology of these zoonotic infections and how to prevent human infection in the best way.

Human Infections by Multiple Spotted Fever Group Rickettsiae in Tennessee.

Rocky Mountain spotted fever is the most common tick-borne disease in Tennessee. However, Rickettsia rickettsii has rarely been isolated from endemic ticks, suggesting rickettsioses may be caused by other species. A total of 56 human serum samples that were serologically positive for exposure to Rickettsia were obtained from commercial laboratories in 2010 and 2011. In addition, 20 paired sera from patients with encephalitis and positive Rickettsia serology were obtained from the Tennessee Unexplained Encephalitis Surveillance (TUES) study. Using an immunofluorescence assay, reactivity of the sera to R. rickettsii, Rickettsia montanensis, Rickettsia parkeri, and Rickettsia amblyommii was tested, and a comparison of endpoint titers was used to determine the probable antigen that stimulated the antibody response. Cross-absorption was conducted for 94.8% (N = 91) of the samples due to serologic cross-reactivity. Of the commercial laboratory samples, 55.4% (N = 31) had specific reactivity to R. amblyommii and 44.6% (N = 25) were indeterminate. Of the paired TUES samples, 20% (N = 4) had specific reactivity to R. amblyommii, 5% (N = 1) to R. montanensis, and 5% (N = 1) to R. parkeri Patients with specific reactivity to R. amblyommii experienced fever (75%), headache (68%) and myalgia (58%). Rash (36%) and thrombocytopenia (40%) were less common. To our knowledge, this is the first time R. amblyommii has been reported as a possible causative agent of rickettsioses in Tennessee.

Larvae of Ixodes ricinus transmit Borrelia afzelii and B. miyamotoi to vertebrate hosts.

BackgroundLyme borreliosis is the most common tick-borne human disease and is caused by Borrelia burgdorferi sensu lato (s.l.). Borrelia miyamotoi, a relapsing fever spirochaete, is transmitted transovarially, whereas this has not been shown for B. burgdorferi (s.l). Therefore, B. burgdorferi (s.l) is considered to cycle from nymphs to larvae through vertebrates. Larvae of Ixodes ricinus are occasionally B. burgdorferi (s.l) infected, but their vector competence has never been studied.MethodsWe challenged 20 laboratory mice with field-collected larvae of I. ricinus. A subset of these larvae was analysed for infections with B. burgdorferi (s.l) and B. miyamotoi. After three to four challenges, mice were sacrificed and skin and spleen samples were analysed for infection by PCR and culture.ResultsField-collected larvae were naturally infected with B. burgdorferi (s.l) (0.62 %) and B. miyamotoi (2.0 %). Two mice acquired a B. afzelii infection and four mice acquired a B. miyamotoi infection during the larval challenges.ConclusionWe showed that larvae of I. ricinus transmit B. afzelii and B. miyamotoi to rodents and calculated that rodents have a considerable chance of acquiring infections from larvae compared to nymphs. As a result, B. afzelii can cycle between larvae through rodents. Our findings further imply that larval bites on humans, which easily go unnoticed, can cause Lyme borreliosis and Borrelia miyamotoi disease.

Identification of a novel pathogenic Borrelia species causing Lyme borreliosis with unusually high spirochaetaemia: a descriptive study

Lyme borreliosis is the most common tick-borne disease in the northern hemisphere. It is a multisystem disease caused by Borrelia burgdorferi sensu lato genospecies and characterised by tissue localisation and low spirochaetaemia. In this study we aimed to describe a novel Borrelia species causing Lyme borreliosis in the USA. At the Mayo clinic, from 2003 to 2014, we tested routine clinical diagnostic specimens from patients in the USA with PCR targeting the oppA1 gene of B burgdorferi sensu lato. We identified positive specimens with an atypical PCR result (melting temperature outside of the expected range) by sequencing, microscopy, or culture. We collected Ixodes scapularis ticks from regions of suspected patient tick exposure and tested them by oppA1 PCR. 100 545 specimens were submitted by physicians for routine PCR from Jan 1, 2003 to Sept 30, 2014. From these samples, six clinical specimens (five blood, one synovial fluid) yielded an atypical oppA1 PCR product, but no atypical results were detected before 2012. Five of the six patients with atypical PCR results had presented with fever, four had diffuse or focal rash, three had symptoms suggestive of neurological inclusion, and two were admitted to hospital. The sixth patient presented with knee pain and swelling. Motile spirochaetes were seen in blood samples from one patient and cultured from blood samples from two patients. Among the five blood specimens, the median oppA1 copy number was 180 times higher than that in 13 specimens that tested positive for B burgdorferi sensu stricto during the same time period. Multigene sequencing identified the spirochaete as a novel B burgdorferi sensu lato genospecies. This same genospecies was detected in ticks collected at a probable patient exposure site. We describe a new pathogenic Borrelia burgdorferi sensu lato genospecies (candidatus Borrelia mayonii) in the upper midwestern USA, which causes Lyme borreliosis with unusually high spirochaetaemia. Clinicians should be aware of this new B burgdorferi sensu lato genospecies, its distinct clinical features, and the usefulness of oppA1 PCR for diagnosis. US Centers for Disease Control and Prevention Epidemiology and Laboratory Capacity for Infectious Diseases (ELC) Cooperative Agreement and Mayo Clinic Small Grant programme.

Individual and environmental factors associated with the seroprevalence of Borrelia burgdorferi in Belgian farmers and veterinarians

BackgroundLyme disease (LD) is a common tick-borne disease in Europe. Diverse factors at various scales determine the spatial distribution of Borrelia burgdorferi infection risk and a better understanding of those factors in a spatially explicit framework is needed for disease management and prevention. While the ecology of ticks and the landscape favoring their abundance have been extensively studied, the environmental conditions favoring an intense contact with susceptible humans, including groups at risk, are sparse. The aim of this study is to assess which individual and environmental factors can favor B. burgdorferi infection in a Belgian group professionally at risk.MethodsSerological results of 127 veterinarians and farmers enrolled in this study were analyzed, taking into account their municipality of residence. Using binary logistic regression and considering interaction terms, the joint effects of landscape composition and configuration, and forest and wildlife management were examined.ResultsSeven of the 127 workers were seropositive for LD, leading to a seroprevalence of 5.51%. Seropositivity was higher in older persons. The proportion of forest and semi-natural habitats and wetland had a positive impact on LD seroprevalence while arable land–grassland ecotones had a negative one. Our results confirmed the need to consider complex interactions between landscape variables in order to model risk.ConclusionsOur data show that LD has to be considered as a risk for farmers and veterinarians. Rather than focusing either on ecological aspects of tick and pathogen distribution or on purely epidemiological aspects such as individual risk factors, our model highlights the role of human–environment interactions in LD risk assessment.

Quantification of Borrelia burgdorferi Membrane Proteins in Human Serum: A New Concept for Detection of Bacterial Infection.

The Borrelia burgdorferi spirochete is the causative agent of Lyme disease, the most common tick-borne disease in the United States. The low abundance of bacterial proteins in human serum during infection imposes a challenge for early proteomic detection of Lyme disease. To address this challenge, we propose to detect membrane proteins released from bacteria due to disruption of their plasma membrane triggered by the innate immune system. These membrane proteins can be separated from the bulk of serum proteins by high-speed centrifugation causing substantial sample enrichment prior to targeted protein quantification using multiple reaction monitoring mass spectrometry. This new approach was first applied to detection of B. burgdorferi membrane proteins supplemented in human serum. Our results indicated that detection of B. burgdorferi membrane proteins, which are ≈10(7) lower in abundance than major serum proteins, is feasible. Therefore, quantitative analysis was also carried out for serum samples from three patients with acute Lyme disease. We were able to demonstrate the detection of ospA, the major B. burgdorferi lipoprotein at the level of 4.0 fmol of ospA/mg of serum protein. The results confirm the concept and suggest that the proposed approach can be expanded to detect other bacterial infections in humans, particularly where existing diagnostics are unreliable.