Common Tick-borne Disease Research Articles

TickPath Layerplex: adaptation of a real-time PCR methodology for the simultaneous detection and molecular surveillance of tick-borne pathogens

Tick-borne diseases (TBD) are common across the United States and can result in critical and chronic diseases in a variety of veterinary patients. Moreover, borreliosis, anaplasmosis, rickettsiosis, ehrlichiosis, and babesiosis are zoonotic and have been cited as the most common TBDs. Molecular diagnostic methodologies utilized for screening domestic dogs for these causative agents include real-time PCR (qPCR) assays in both singleplex and multiplex formats. However, current limitations of qPCR instruments restrict the number of fluorogenic labels that can be differentiated by the instrument for a given reaction. This study describes the development of the TickPath Layerplex, a diagnostic assay based on qPCR methodology that was adapted for the simultaneous detection and characterization of 11 pathogens responsible for causing 5 common TBDs in domestic dogs. The analytical and diagnostic performance of the layerplex assay was evaluated and shown to be compatible with common instruments utilized in molecular diagnostic laboratories. Test results revealed no inhibition or reduction in sensitivity during validation of the layerplex assay, and the limit of detection was determined to be near 16 genome copy equivalents per microliter. Overall, the high sensitivity, specificity, and screening capability of the assay demonstrate its utility for broadly screening dogs for common TBDs.

Lyme disease

Lyme disease (LD) is the most common tick-borne infectious disease in the Northern hemisphere. LD can present with a wide range of symptoms depending on time since infection; from localised skin reactions such as erythema migrans, to widespread multi-system involvement. There may be non-specific symptoms of malaise, aching joints and muscles, and cognitive effects. Treatment with antibiotics is effective, especially if started in the early stages of infection. There is rising awareness of LD by the general public through media coverage and high-profile celebrity cases. Greater awareness has benefits, such as increased diagnosis and treatment of LD. However, cases in the media tend to highlight delays in diagnosis and complications of LD, which can lead to high levels of patient anxiety about the risks of LD.

Implementation of preventive measures against tick-borne infections in a non-endemic area for tick-borne encephalitis—Results from a population-based survey in Lower Saxony, Germany

Lyme borreliosis (LB) and tick-borne encephalitis (TBE) are the most common tick-borne diseases in Germany. While for LB only non-specific prevention strategies exist, TBE can be additionally prevented by vaccination. It is unclear to which extent non-specific prevention strategies are applied by individuals living in non-endemic areas for TBE in Germany, and whether TBE vaccination status affects their implementation. Participants of the HaBIDS panel (Hygiene and Behavior Infectious Diseases Study) from four counties of Lower Saxony were invited to fill out a questionnaire on their TBE vaccination status, their LB diagnoses as well as their knowledge, attitudes, and practice related to prevention measures for tick-borne diseases. Based on self-reported data we estimated cumulative lifetime incidence (CUM) and incidence of LB as well as TBE vaccination coverage. One year later, participants received a supplementary questionnaire focusing on reasons for vaccination against TBE and compliance with the vaccination schedule.1,573 (74.2% of those invited) panel members aged 18–69 years participated in this study. Of these, 22.8% reported to have ever been vaccinated against TBE. The estimated CUM of LB was 5.1% (95%-CI: 4.1%–6.4%), and the incidence was 1.09 per 1,000 person years (95%-CI: 0.87–1.36). 98% of participants knew that LB is transmitted by the bite of an infected tick, but about 50% didn’t know that TBE vaccination does not protect against LB. Even though about 80% of study participants were convinced that recommended non-specific prevention strategies were indeed protective, a much lower proportion implemented them. TBE-vaccinated participants were better informed about tick-borne diseases compared to non-vaccinated participants, whereby being vaccinated did not negatively affect implementation of non-specific prevention strategies. Based on data from the supplementary questionnaire, traveling to endemic areas (75.3%) was the main reason for TBE vaccination; 33.0% of those vaccinated had a complete vaccination schedule with three doses.Our study in a TBE non-endemic area revealed deficits in knowledge about which pathogens are covered by TBE vaccination, and a lack in the implementation of non-specific prevention measures. TBE vaccination was not associated with a reduced uptake of non-specific prevention measures.

Borelioza z Lyme w Polsce w 2017 roku

Lyme disease is the most common tick-borne disease, caused by spirochetes of the genus Borrelia, transmitted by ticks of the Ixodes genus. Infection caused by Borrelia burgdorferi can occur throughout Poland and therefore, according to ECDC description, the whole country should be considered as an endemic area. The aim of the study is to assess the epidemiological situation of Lyme disease in Poland in 2017 in comparison to the situation in previous years. The epidemiological situation of Lyme disease in Poland was assessed on data from the annual bulletin “Infectious diseases and poisoning in Poland in 2017”. (MP Czarkowski et al., Warsaw 2018, NIZP-PZH, GIS). In 2017 were registered 21,514 Lyme disease cases i.e. 1.48% more than in the previous year and 2,324 people were hospitalized. Epidemiological situation in Western European countries and Poland are similar. A slightly increase in 2017 and lack of a clear trend in individual voivodeships may indicate, that a very high level of sensitivity of epidemiological surveillance has been achieved.

The Emerging Role of Microbial Biofilm in Lyme Neuroborreliosis.

Lyme borreliosis (LB) is the most common tick-borne disease caused by the spirochete Borrelia burgdorferi in North America and Borrelia afzelii or Borrelia garinii in Europe and Asia, respectively. The infection affects multiple organ systems, including the skin, joints, and the nervous system. Lyme neuroborreliosis (LNB) is the most dangerous manifestation of Lyme disease, occurring in 10–15% of infected individuals. During the course of the infection, bacteria migrate through the host tissues altering the coagulation and fibrinolysis pathways and the immune response, reaching the central nervous system (CNS) within 2 weeks after the bite of an infected tick. The early treatment with oral antimicrobials is effective in the majority of patients with LNB. Nevertheless, persistent forms of LNB are relatively common, despite targeted antibiotic therapy. It has been observed that the antibiotic resistance and the reoccurrence of Lyme disease are associated with biofilm-like aggregates in B. burgdorferi, B. afzelii, and B. garinii, both in vitro and in vivo, allowing Borrelia spp. to resist to adverse environmental conditions. Indeed, the increased tolerance to antibiotics described in the persisting forms of Borrelia spp., is strongly reminiscent of biofilm growing bacteria, suggesting a possible role of biofilm aggregates in the development of the different manifestations of Lyme disease including LNB.

The occurrence of three tick-borne pathogens in Ixodes ricinus ticks collected from the area of the Kraków-Częstochowa Upland (Southern Poland)

The common tick Ixodes ricinus is the main vector of Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum and Babesia microti in Europe. The aim of this study was to estimate the potential risk of exposure to common tick-borne diseases in the recreational areas of the Kraków-Częstochowa Upland, Poland with particular emphasis on the city of Częstochowa. The DNA from 459 I. ricinus ticks was used to detect B. burgdorferi s. l., A. phagocytophilum and B. microti by PCR and nested PCR methods. Generally, infectious agents were found in 26.3% of all the examined ticks: B. microti was found in 23.3%, and A. phagocytophilum in 2.4% of the ticks. The protozoan was found mainly in females and nymphs, while A. phagocytophilum was detected mainly in adults. The co-existence of B. microti and A. phagocytophilum was found in 2.1% of the examined ticks. The presence of B. burgdorferi s. l. was not revealed in the examined material. The conducted studies demonstrate the high potential risk of exposure of tourists and pilgrims to B. microti, and a low risk of exposure to A. phagocytophilum and B. burgdorferi s.l. in the examined areas of the Kraków-Częstochowa Upland. Furthermore, the possible co-existence of A. phagocytophilum and B. microti in 3 individual ticks means that infection by multiple infectious agents is possible. The obtained results highlight the need to conduct further research on tick-borne pathogens in this region of Poland.

"Ticking Bomb": The Impact of Climate Change on the Incidence of Lyme Disease.

Lyme disease (LD) is the most common tick-borne disease in North America. It is caused by Borrelia burgdorferi and transmitted to humans by blacklegged ticks, Ixodes scapularis. The life cycle of the LD vector, I. scapularis, usually takes two to three years to complete and goes through three stages, all of which are dependent on environmental factors. Increases in daily average temperatures, a manifestation of climate change, might have contributed to an increase in tick abundance via higher rates of tick survival. Additionally, these environmental changes might have contributed to better host availability, which is necessary for tick feeding and life cycle completion. In fact, it has been shown that both tick activity and survival depend on temperature and humidity. In this study, we have examined the relationship between those climatic variables and the reported incidence of LD in 15 states that contribute to more than 95% of reported cases within the Unites States. Using fixed effects analysis for a panel of 468 U.S. counties from those high-incidence states with annual data available for the period 2000–2016, we have found sizable impacts of temperature on the incidence of LD. Those impacts can be described approximately by an inverted U-shaped relationship, consistent with patterns of tick survival and host-seeking behavior. Assuming a 2°C increase in annual average temperature—in line with mid-century (2036–2065) projections from the latest U.S. National Climate Assessment (NCA4)—we have predicted that the number of LD cases in the United States will increase by over 20 percent in the coming decades. These findings may help improving preparedness and response by clinicians, public health professionals, and policy makers, as well as raising public awareness of the importance of being cautious when engaging in outdoor activities.

Current Status of Tick-Borne Diseases in South Korea.

Bites with tick-borne pathogens can cause various bacterial, viral, or parasitic diseases in humans. Tick-transmitted diseases are known as contributing factors to the increasing incidence and burden of diseases. The present article investigated the epidemiology of tick-borne diseases in South Korea. The incidence and distribution of common tick-borne diseases in Korea (Lyme disease, Q fever, and severe fever with thrombocytopenia syndrome [SFTS]) were investigated and analyzed, using data from the Korea Centers for Disease Control and Prevention (KCDC) infectious disease reporting system. A literature review was compiled on the current status of uncommon tick-borne diseases (Rickettsia, anaplasmosis, ehrlichiosis, bartonellosis, tularemia, tick-borne encephalitis, and babesiosis). In South Korea, SFTS is an emerging disease, showing a rapid increase in reports since 2012, with high mortality. Likewise, reports of Lyme disease and Q fever cases have also been rapidly increasing during 2012-2017, although caution should be taken when interpreting these results, considering the likely influence of increased physician awareness and reporting of these diseases. Other tick-borne diseases reported in South Korea included spotted fever group rickettsiae, anaplasmosis, ehrlichiosis, tularemia, Bartonella, and babesiosis. Evidences on human infection with tick-borne encephalitis virus and Crimean-Congo hemorrhagic fever were recently unavailable, but both need constant monitoring.

Recent strategies for the diagnosis of early Lyme disease.

Lyme disease (LD) is the most common tick-borne disease in the Northern Hemisphere. As the most prevalent vector-borne disease in the USA, LD affects 300,000 human cases each year. LD is caused by inoculation of the bacterial spirochete, Borrelia burgdorferi sensu lato, from an infected tick. If not treated quickly and completely, the bacteria disseminate from the tick's biting site into multiple organs including the joints, heart, and brain. Thus, the best outcome from medical intervention can be expected with early detection and treatment with antibiotics, prior to multi-organ dissemination. In the absence of a characteristic rash, LD is diagnosed using serological testing involving enzyme-linked immunosorbent assay (ELISA) followed by western blotting, which is collectively known as the two-tier algorithm. These assays detect host antibodies against the bacteria, but are hampered by low sensitivity, which can miss early LD cases. This review discusses the application of some current assays for diagnosing LD clinically, thus providing a foundation for exploring newer techniques being developed in the laboratory for more sensitive detection of early LD.

Spotted fever group Rickettsiae in Ticks from Missouri

Tick-borne rickettsioses pose a major health threat among vector-borne infections in Missouri but there are some uncertainties regarding the vector competence and range of tick species, as well as the virulence of certain bacterial species. A survey was developed and implemented to assess local healthcare practitioners’ awareness of the prevalence and diagnosis of tick-borne diseases. In addition, ticks collected from rural areas of St. Louis County, Missouri, were evaluated to detect spotted fever group (SFG) rickettsiae and to determine the most common tick species present. Physician responses showed a good general awareness of tick-borne diseases and antibiotic choices but responses varied regarding length of treatment, the most common tick-borne diseases, and tick vectors. No new tick vectors were collected in the area; Rickettsia amblyommatis was the predominant SFG species, and it was detected in Amblyomma americanum, Dermacentor variabilis, andIxodes scapularis; Rickettsia montanensis was detected in D. variabilis. The high prevalence of Rickettsia amblyommatis in these ticks suggests that there is a high risk of exposure to this SFG rickettsial species to humans and that it may be providing some cross-protective immunity to R. rickettsii.

Horses as a Potential Reservoir of Lyme Borreliosis in Jeju-do, Korea

Lyme borreliosis (LB) is the most common tick-borne infectious disease in North America, and it was designated as a national notifiable infectious disease in Korea in December 2010. While no cases in Jeju-do were recorded from 2012 to 2016, a recent survey reported that the seroprevalence of Borrelia burgdorferi using enzyme-linked immunosorbent assays in horses in Jeju-do was 19.0% (95% confidence interval, 12.0 to 28.3%). This fact suggests that horses may be a potential reservoir of LB in Jeju-do and that individuals in close contact with horses may be a high-risk group. Thus, a serological study in this high-risk group is urgently needed.

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

BackgroundLyme 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.MethodsThe 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.ResultsOverall, 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).ConclusionsLong-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.

Detection of Borrelia in Ixodes scapularis ticks by silver stain, immunohistochemical and direct immunofluorescent methods.

Lyme disease (LD) is one of the most common tick-borne diseases caused by several Borrelia species of spirochetes. Ixodes scapularis is responsible for the transmission of LD in the northeastern United States. The rate of infection varies with the duration of tick attachment to the host; however, this information may be unknown. In skin biopsies, it is often difficult to identify spirochetes. Testing of ticks is not routinely performed. Treatment is established by clinical presentation. To test paraffin-embedded I. scapularis ticks for Borrelia by different methods. We examined 20 paraffin-embedded ticks by silver stain, immunohistochemical (IHC) and direct immunofluorescent (DIF) methods and compared the percentage of positivity with DIF results from the Connecticut Agricultural Experiment Station. The results were similar by DIF, which proved to be the most sensitive method, followed by the silver stain and IHC. We found that the identification of spirochetes in paraffin-embedded ticks was less difficult than in tissue with a comparable turnaround time to that of a routine biopsy. Timely identification of Borrelia in ticks may influence the clinical management of the patients.

Low probability of a dilution effect for Lyme borreliosis in Belgian forests

An increasing number of studies have investigated the consequences of biodiversity loss for the occurrence of vector-borne diseases such as Lyme borreliosis, the most common tick-borne disease in the northern hemisphere. As host species differ in their ability to transmit the Lyme borreliosis bacteria Borrelia burgdorferi s.l. to ticks, increased host diversity can decrease disease prevalence by increasing the proportion of dilution hosts, host species that transmit pathogens less efficiently. Previous research shows that Lyme borreliosis risk differs between forest types and suggests that a higher diversity of host species might dilute the contribution of small rodents to infect ticks with B. afzelii, a common Borrelia genospecies. However, empirical evidence for a dilution effect in Europe is largely lacking. We tested the dilution effect hypothesis in 19 Belgian forest stands of different forest types along a diversity gradient. We used empirical data and a Bayesian belief network to investigate the impact of the proportion of dilution hosts on the density of ticks infected with B. afzelii, and identified the key drivers determining the density of infected ticks, which is a measure of human infection risk. Densities of ticks and B. afzelii infection prevalence differed between forest types, but the model indicated that the density of infected ticks is hardly affected by dilution. The most important variables explaining variability in disease risk were related to the density of ticks. Combining empirical data with a model-based approach supported decision making to reduce tick-borne disease risk. We found a low probability of a dilution effect for Lyme borreliosis in a north-western European context. We emphasize that under these circumstances, Lyme borreliosis prevention should rather aim at reducing tick-human contact rate instead of attempting to increase the proportion of dilution hosts.

Citizen Science and Community Engagement in Tick Surveillance-A Canadian Case Study.

Lyme disease is the most common tick-borne disease in North America and Europe, and on-going surveillance is required to monitor the spread of the tick vectors as their populations expand under the influence of climate change. Active surveillance involves teams of researchers collecting ticks from field locations with the potential to be sites of establishing tick populations. This process is labor- and time-intensive, limiting the number of sites monitored and the frequency of monitoring. Citizen science initiatives are ideally suited to address this logistical problem and generate high-density and complex data from sites of community importance. In 2014, the same region was monitored by academic researchers, public health workers, and citizen scientists, allowing a comparison of the strengths and weaknesses of each type of surveillance effort. Four community members persisted with tick collections over several years, collectively recovering several hundred ticks. Although deviations from standard surveillance protocols and the choice of tick surveillance sites makes the incorporation of community-generated data into conventional surveillance analyses more complex, this citizen science data remains useful in providing high-density longitudinal tick surveillance of a small area in which detailed ecological observations can be made. Most importantly, partnership between community members and researchers has proven a powerful tool in educating communities about of the risk of tick-vectored diseases and in encouraging tick bite prevention.

Correlation between chronic arthritis patients confirmed with questionnaire and serologic test of Lyme disease

Lyme borreliosis is the most common tick-borne disease, and frequency of arthritis complication later. The objective of this study was to determine the seroprevalence of Lyme disease and to evaluate its correlation with chronic arthritis. This epidemiologic cross sectional study included 41 healthy individuals who had chronic arthritis and bitten by ticks underwent questionnaires, and laboratory tests consisted of a routine blood sample, serum uric acid, and IgG ELISA for Lyme. There was 7.32% presence of positive IgG for Lyme. Samples with positive IgG for Lyme were further evaluated for rheumatology marker. We found three samples with a positive rheumatoid factor, two samples had positive anti-MCV, and 1 sample had slightly increased CRP. Three Lyme positive samples had normal EULAR scoring. It was the first Lyme disease case found in Indonesia, particularly in 4 villages of Sibolangit, Deli Serdang, North Sumatera. The assessment made by analysis the questionnaire, evaluation the blood test, and confirmed positive Lyme disease, and at last, we found the correlation between chronic arthritis with positive test Lyme.

Status of theileriosis among herbivores in Iran: A systematic review and meta-analysis.

Aim:Theileriosis is a protozoal disease caused by Theileria spp. mostly in warm-blooded vertebrates worldwide. It is one of the common tick-borne diseases among domestic animals in tropical and sub-tropical regions, which have a variety of unlikable effects on health economy and animal welfare. In the present study, the prevalence of theileriosis among domestic farm animals in Iran was systematically evaluated.Methods:To identify the related papers, 10 English and Persian databases, including PubMed, Science Direct, Scopus, Web of Science, Medical Subject Headings, Google Scholar, Magiran, Barakatns (formerly Iranmedex), Elm net, and Scientific Information Database, were appraised for articles published throughout 1999-2017.Results:A total of 56 papers, providing the examination of 11,317 cattle, 9394 sheep, 2991 buffaloes, 1504 horses, 600 goats, and 212 donkeys were analyzed, matching for the prevalence of theileriosis from different parts of Iran were permitted for our allowing checklist. The overall prevalence of theileriosis among domestic herbivores was expected to be 19% (95% confidence interval: 15%, 22%). Our findings highlighted the average of the maximum prevalence in Razavi Khorasan (60.4%) and West Azerbaijan (49.1%) and the minimum in Mazandaran (1.1%) and East Azerbaijan provinces (2.2%), respectively. The high prevalence of Theileria infection in the herbivores (mainly sheep) verifies the well-known enzootic episode of theileriosis in Iran, predominantly in northeastern and western parts of the country.Conclusion:Our results suggested updated and imperative information on the true burden of theileriosis in Iran. Moreover, it could be supporting the gaps among monitoring, prevention, and control arrangements to improve the health economy, particularly among dairy farm animals.

Haemoparasitic agents associated with ovine babesiosis: A possible negative interaction between Babesia ovis and Theileria ovis

Babesiosis, theileriosis, and anaplasmosis are the most common tick-borne diseases in sheep. The majority of anaplasmosis and theileriosis are subclinical; however, babesiosis causes severe infections in small ruminants. Although there are many reports of co-infections with the agents of these diseases, their clinical severity compared with either of the infections alone is unknown. Within the host, interactions between co-infecting species may cause variations in clinical presentation and response to therapy. The aim of this study was to determine the tick-borne agents in sheep located at sites where fatal disease outbreaks caused by babesiosis have commonly been reported. Two hundred and nine sheep with clinical signs suggestive of ovine babesiosis were included in the study. The initial diagnosis of haemoparasites was based on clinical symptoms and microscopy and was confirmed using PCR assays. The blood samples were examined for the presence of Babesia ovis (B. ovis), Anaplasma ovis (A. ovis), A. phagocytophilum, and Theileria ovis (T. ovis). The results showed 86.12% of the animals were infected with one or more pathogens. B. ovis was the dominant pathogen. Overall, the infection rate of B. ovis, A. ovis, T. ovis, and A. phagocytophilum was 70.81%, 56.94%, 21.05%, and 2.39%, respectively. The infection rate of B. ovis alone (31.11%) was higher than A. ovis (9.44%) or T. ovis (1.67%) alone. Co-infections were found at a higher percentage (57.78%) than single infections (42.22%). A. ovis was detected in the blood of a high percentage (98.07%) of co-infected animals. Coexistence of B. ovis and A. ovis (34.45%) was more common than other combinations of species. There was a noticeably low level of co-occurrence between B. ovis and T. ovis (1.11%). During the study, 11 sick animals did not survive despite treatment. Seven were infected with B. ovis alone, three had a dual infection with B. ovis and A. ovis, and one had B. ovis, A. ovis, and T. ovis.

Eliminating Factor H-Binding Activity of Borrelia burgdorferi CspZ Combined with Virus-Like Particle Conjugation Enhances Its Efficacy as a Lyme Disease Vaccine.

The spirochete Borrelia burgdorferi is the causative agent of Lyme disease, the most common tick-borne disease in the US and Europe. No potent human vaccine is currently available. The innate immune complement system is vital to host defense against pathogens, as complement activation on the surface of spirochetes results in bacterial killing. Complement system is inhibited by the complement regulator factor H (FH). To escape killing, B. burgdorferi produces an outer surface protein CspZ that binds FH to inhibit complement activation on the cell surface. Immunization with CspZ alone does not protect mice from infection, which we speculate is because FH-binding cloaks potentially protective epitopes. We modified CspZ by conjugating to virus-like particles (VLP-CspZ) and eliminating FH binding (modified VLP-CspZ) to increase immunogenicity. We observed greater bactericidal antibody titers in mice vaccinated with modified VLP-CspZ: A serum dilution of 1:395 (modified VLP-CspZ) vs 1:143 (VLP-CspZ) yielded 50% borreliacidal activity. Immunizing mice with modified VLP-CspZ cleared spirochete infection, as did passive transfer of elicited antibodies. This work developed a novel Lyme disease vaccine candidate by conjugating CspZ to VLP and eliminating FH-binding ability. Such a strategy of conjugating an antigen to a VLP and eliminating binding to the target ligand can serve as a general model for developing vaccines against other bacterial infectious agents.

Surveillance for and Discovery of Borrelia Species in US Patients Suspected of Tickborne Illness.

Tick-transmitted Borrelia fall into 2 heterogeneous bacterial complexes comprised of multiple species, the relapsing fever (RF) group and the Borrelia burgdorferi sensu lato group, which are the causative agents of Lyme borreliosis (LB), the most common tickborne disease in the Northern Hemisphere. Geographic expansion of LB in the United States and discovery of emerging Borrelia pathogens underscores the importance of surveillance for disease-causing Borrelia. De-identified clinical specimens, submitted by providers throughout the United States, for patients suspected of LB, anaplasmosis, ehrlichiosis, or babesiosis were screened using a Borrelia genus-level TaqMan polymerase chain reaction (PCR). Borrelia species and sequence types (STs) were characterized by multilocus sequence typing (MLST) utilizing next-generation sequencing. Among 7292 specimens tested, 5 Borrelia species were identified: 2 causing LB, B. burgdorferi (n = 25) and B. mayonii (n = 9), and 3 RF borreliae, B. hermsii (n = 1), B. miyamotoi (n = 8), and Candidatus B. johnsonii (n = 1), a species previously detected only in the bat tick, Carios kelleyi. ST diversity was greatest for B. burgdorferi-positive specimens, with new STs identified primarily among synovial fluids. These results demonstrate that broad PCR screening followed by MLST is a powerful surveillance tool for uncovering the spectrum of disease-causing Borrelia species, understanding their geographic distribution, and investigating the correlation between B. burgdorferi STs and joint involvement. Detection of Candidatus B. johnsonii in a patient with suspected tickborne disease suggests this species may be a previously undetected cause of illness in humans exposed to bat ticks.