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Background: Cases of reported tick-borne diseases in humans have increased over the past decades. Strategies informing the public about ticks, their associated diseases, and preventive measures are often highlighted as important in limiting pathogen transfer and disease. However, knowledge about the motivation for people to apply preventative measures is sparse., Methods: The aim was to examine if Protection Motivation Theory, a model of disease prevention and health promotion, can predict the use of protective measures against ticks. Ordinal logistic regression and Chi-square tests were used on data from a cross-sectional survey with respondents from Denmark, Norway, and Sweden (n = 2658). We examined the effect of (1) the perceived seriousness of tick bites, Lyme borreliosis (LB), and tick-borne encephalitis (TBE), and (2) the perceived probability of getting a tick bite, Lyme borreliosis, and tick-borne encephalitis on protection against ticks. Finally, we examined if there was an association between the use of a protective measure and the perceived efficacy of that measure., Results: The perceived seriousness of a tick bite and LB significantly predict who is more likely to apply protective measures for all three countries combined. The perceived seriousness of TBE did not significantly predict the level of adoption of protective measures applied by respondents. The perceived likelihood of getting a tick bite within the next 12 months and the perceived likelihood of getting LB if bitten by a tick significantly predicted the application of protective measures. However, the increases in the likelihood of protection were very small. The application of a certain type of protection was always correlated with the perceived efficacy of the same protective measure., Conclusion: Some variables of PMT may be used to predict the level of adoption of protection applied against ticks and tick-borne diseases. We found that the perceived seriousness of a tick bite and LB significantly predict the level of adoption protection. The perceived likelihood of getting a tick bite or LB also significantly predicted the level of adoption of protection, although the change was very small. The results regarding TBE were less clear. Lastly, there was an association between applying a protective measure and the perceived efficacy of the same measure., (© 2023. The Author(s).)

Background: Infectious diseases are emerging across temperate regions of the world, and, for some, links have been made between landscapes and emergence dynamics. For tick-borne diseases, public parks may be important exposure sites for people living in urbanized areas of North America and Europe. In most cases, we know more about the ecological processes that determine the hazard posed by ticks as disease vectors than we do about how human population exposure varies in urban natural parks., Methods: In this study, infrared counters were used to monitor visitor use of a public natural park in southern Quebec, Canada. A risk index representing the probability of encounters between humans and infected vectors was constructed. This was done by combining the intensity of visitor trail use and the density of infected nymphs obtained from field surveillance. Patterns of risk were examined using spatial cluster analysis. Digital forest data and park infrastructure data were then integrated using spatially explicit models to test whether encounter risk levels and its components vary with forest fragmentation indicators and proximity to park infrastructure., Results: Results suggest that, even at a very fine scales, certain landscape features and infrastructure can be predictors of risk levels. Both visitors and Borrelia burgdorferi-infected ticks concentrated in areas where forest cover was dominant, so there was a positive association between forest cover and the risk index. However, there were no associations between indicators of forest fragmentation and risk levels. Some high-risk clusters contributed disproportionately to the risk distribution in the park relative to their size. There were also two high-risk periods, one in early summer coinciding with peak nymphal activity, and one in early fall when park visitation was highest., Conclusions: Here, we demonstrate the importance of integrating indicators of human behaviour visitation with tick distribution data to characterize risk patterns for tick-borne diseases in public natural areas. Indeed, understanding the environmental determinants of human-tick interactions will allow organisations to deploy more effective risk reduction interventions targeted at key locations and times, and improve the management of public health risks associated with tick-borne diseases in public spaces., (© 2024. Crown.)

Background: Lyme borreliosis is the most common tick-borne disease in Europe and is often caused by Borrelia afzelii, which is transmitted by Ixodes ricinus ticks. The prevalence and abundance of infected ticks fluctuate in time and space, influencing human infection risk. Rodents are reservoir hosts for B. afzelii and important feeding hosts for larval ticks. In the study reported here, we examined how variation in rodent abundance is associated with B. afzelii infection prevalence in ticks, the density of nymphs (DON) and the density of infected nymphs (DIN) in the following year. We further analysed the relationships between the abundance of infected rodents and nymphal infection prevalence (NIP) and DIN., Methods: We conducted a study that combined experimental and observational approaches on 15 islands (10 small islands and 5 large islands) in Finland. On all of the islands, ticks and rodents were monitored and sampled during the summer of 2019, with the monitoring of tick abundance and sampling continuing into the spring of 2020. On five of the 10 small islands, captured rodents were removed from the island ("removal" islands), and on the other five small islands, captured rodents were released back to the trapping site after marking and sampling ("control" islands). On the five large islands, captured rodents were released back to the trapping site after marking and sampling. The presence of B. afzelii from nymph and rodent samples was examined., Results: The results of the experimental study showed that neither treatment (removal), rodent abundance index nor abundance index of infected rodents in 2019 was associated with DON, NIP or DIN in 2020. Based on data from the observational study, the NIP in 2020 decreased with increasing rodent abundance index and abundance index of infected rodents in 2019. However, the DIN in 2020 was not associated with the rodent abundance index or the abundance index of infected rodents in 2019. In addition, in the observational study, DON in 2020 increased with increasing rodent abundance index., Conclusions: Our results suggest that low rodent abundance during the tick activity period is not sufficient for reducing the disease hazard and, hence, rodent removal may not be a feasible control measure in natural ecosystems., (© 2024. The Author(s).)

Background: Borrelia burgdorferi is the spirochete that causes Lyme Borreliosis (LB), which is a zoonotic tick-borne disease of humans and domestic animals. Hard ticks are obligate haematophagous ectoparasites that serve as vectors of Borrelia burgdorferi. Studies on the presence of Lyme borreliosis in Egyptian animals and associated ticks are scarce., Methods: This study was conducted to detect B. burgdorferi in different tick vectors and animal hosts. Three hundred animals (dogs=100, cattle=100, and camels=100) were inspected for tick infestation. Blood samples from 160 tick-infested animals and their associated ticks (n=1025) were collected and examined for the infection with B. burgdorferi by polymerase chain reaction (PCR) and sequencing of the 16S rRNA gene. The identified tick species were characterized molecularly by PCR and sequencing of the ITS2 region., Results: The overall tick infestation rate among examined animals was 78.33% (235/300). The rate of infestation was significantly higher in camels (90%), followed by cattle (76%) and dogs (69%); (P = 0.001). Rhipicephalus sanguineus, Rhipicephalus (Boophilus) annulatus, and both Hyalomma dromedarii and Amblyomma variegatum, were morphologically identified from infested dogs, cattle, and camels; respectively. Molecular characterization of ticks using the ITS2 region confirmed the morphological identification, as well as displayed high similarities of R. sanguineus, H. dromedarii, and A. Variegatu with ticks identified in Egypt and various continents worldwide. Just one dog (1.67%) and its associated tick pool of R. sanguineus were positive for B. burgdorferi infection. The 16S rRNA gene sequence for B. burgdorferi in dog and R. sanguineus tick pool showed a 100% homology., Conclusion: Analyzed data revealed a relatively low rate of B. burgdorferi infection, but a significantly high prevalence of tick infestation among domesticated animals in Egypt, which possesses a potential animal and public health risk. Additionally, molecular characterization of ticks using the ITS2 region was a reliable tool to discriminate species of ticks and confirmed the morphological identification.

Background: Ixodid ticks are important vectors for zoonotic pathogens, with Ixodes ricinus being the most important in Europe. Rodents are hosts of immature life stages of I. ricinus ticks and are considered main reservoirs for tick-borne pathogens, e.g. Borrelia burgdorferi. The aim of this study was to analyse the prevalence as well as genospecies and sequence type (ST) diversity of Borrelia burgdorferi sensu lato in ticks and small mammals from central Germany and to elaborate on the influence of environmental and/or individual host and vector factors on Borrelia prevalence., Methods: After species identification, 1167 small mammal skin samples and 1094 ticks from vegetation were screened by B. burgdorferi sensu lato real-time polymerase chain reaction, and positive samples were characterized by multilocus sequence typing. Generalized linear (mixed) models were used to estimate how seasonality, small mammal species/tick life stage and habitat affect individual infection status., Results: In total, 10 small mammal species and three tick species, Ixodes ricinus, Ixodes inopinatus (both considered members of the I. ricinus complex) and Dermacentor reticulatus, were investigated. Borrelia DNA was detected in eight host species, i.e. the striped field mouse (Apodemus agrarius), the yellow-necked field mouse (Apodemus flavicollis), the wood mouse (Apodemus sylvaticus), the water vole (Arvicola amphibius), the bank vole (Clethrionomys glareolus), the field vole (Microtus agrestis), the common vole (Microtus arvalis), and the common shrew (Sorex araneus). Two species were Borrelia negative, the greater white-toothed shrew (Crocidura russula) and the pygmy shrew (Sorex minutus). The average prevalence was 6.2%, with two genospecies detected, Borrelia afzelii and Borrelia garinii, and at least three STs that had not been previously reported in small mammals. Borrelia prevalence in small mammals did not differ between seasons. Six genospecies of Borrelia-Borrelia afzelii, Borrelia valaisiana, Borrelia garinii, Borrelia lusitaniae, Borrelia spielmanii, and Borrelia burgdorferi sensu stricto-and 25 STs of Borrelia, of which 12 have not been previously described at all and five have not been previously reported in Germany, were detected in 13% of I. ricinus complex ticks. Prevalence was highest in adult females (25.3%) and lowest in nymphs (11.4%). Prevalence was significantly higher in ticks from grassland (16.8%) compared to forests (11.4%)., Conclusions: The high level of small mammal diversity in this region of Germany seems to be reflected in a wide variety of genospecies and STs of B. burgdorferi., (© 2022. The Author(s).)

Background: Tick-borne diseases, and especially Lyme Disease (LD), are on the rise in Canada and have been met with increasing public health concern. To face these emerging threats, education on the prevention of tick bites remains the mainstay of public health intervention. The objective of this study was to assess the adoption of preventive behaviors toward tick bites and LD and to investigate the association between behavioral risk factors and reported tick exposure in a Canadian, LD high incidence region (Estrie region, Quebec, Canada)., Methods: A cross-sectional study was conducted in 2018 which used a telephone questionnaire administered to a random sample of 10,790 adult residents of the study region. Questions investigated tick exposure, LD awareness, attitudes towards LD risk, outdoor and preventive behaviors, as well as antibiotic post-exposure prophylaxis (PEP) treatments in the case of a tick bite. Descriptive and multivariable analyses were carried out, considering the nine administrative subregions and the stratified survey design., Results: The sub-regional prevalence of reported tick exposure in the previous year ranged from 3.4 to 21.9%. The proportion of respondents that adopted preventive behaviors varied from 27.0% (tick checks) to 30.1% (tick repellent) and 44.6% (shower after outdoor activities). A minority of respondents (15.9%) that sought healthcare after a tick bite received a PEP treatment. Performing tick checks (Odds ratio = 4.33), time spent outdoors (OR = 3.09) and living in a subregion with a higher public health LD risk level (OR = 2.14) were associated with reported tick exposure in multivariable models., Conclusions: This study highlights the low level of adoption of preventive behaviors against tick bites in a region where LD risk is amongst the highest in Canada. This suggests a concerning lack of improvement in LD prevention, as low levels of adoption were already reported in studies conducted in the last decade. Innovative and evidence-based approaches to improve education on ticks and tick-borne diseases and to promote behavior changes are urgently needed in Canada., (© 2022. The Author(s).)

Background: As the vector-borne diseases tick-borne encephalitis (TBE) and Lyme borreliosis (LB) are common in Germany and transmitted by tick bites, the aim of this study was to assess differences in the number of tick bites in various professions and regions across southern Germany to evaluate the differences in tick-associated risk., Materials and Methods: The analysis is based on three cross-sectional studies that were conducted in 2016 and 2017 in two real-life settings and in one medical setting in Bavaria. All participants filled in a paper-based questionnaire about their history with tick bites. Only adult participants (≥ 18 years) were included in this study., Results: Overall, 3503 individuals (mean age 50.8 ± 15.2 years, median age 53.0 ± 12.2 years, 54.0% female) were included. Of these, 50% worked in an outdoor profession and 56% lived in environs. Around 70% of participants reported at least one previous tick bite. In comparison to indoor workers, forestry workers (OR = 2.50; 95% CI: 1.10-5.68) had the highest risk for a tick bite followed by farmers (OR = 1.22; 95% CI: 1.01-1.47). Furthermore, people living in rural areas (OR = 1.97, 95% CI:1.49-2.59) and environs (OR = 1.98, 95% CI: 1.54-2.55) were twice as likely to have a previous tick bite than people living in urban areas. In general, slightly more tick bites were reported by people living in eastern Bavaria., Conclusion: Rising numbers of TBE and LB indicate the need for further prevention strategies, which should focus on outdoor professions with a higher risk and people living in environs and rural areas., (© 2022. The Author(s).)

Background: Primary care and frontline healthcare providers are often the first point of contact for patients experiencing tick-borne disease (TBD) but face challenges when recognizing and diagnosing these diseases. The specific aim of this study was to gain a qualitative understanding of frontline and primary care providers' knowledge and practices for identifying TBDs in patients., Methods: From fall 2018 to spring 2019, three focus groups were conducted with primary care providers practicing in a small-town community endemic to Lyme disease (LD) and with emerging incidence of additional TBDs. A follow up online survey was distributed to urgent and emergency care providers in the small-town community and an academic medical center within the referral network of the local clinical community in spring and summer 2019. Qualitative analysis of focus group data was performed following a grounded theory approach and survey responses were analyzed through the calculation of descriptive statistics., Results: Fourteen clinicians from three primary care practices participated in focus groups, and 24 urgent and emergency care clinicians completed the survey questionnaire. Four overarching themes emerged from focus group data which were corroborated by survey data. Themes highlighted a moderate level of awareness on diagnosis and treatment of LD among participants and limited knowledge of diagnosis and treatment for two other regionally relevant TBDs, anaplasmosis and babesiosis. Providers described challenges and frustrations in counseling patients with strong preconceptions of LD diagnosis and treatment in the context of chronic infection. Providers desired additional point-of-care resources to facilitate patient education and correct misinformation on the diagnosis and treatment of TBDs., Conclusions: Through this small study, it appears that clinicians in the small-town and academic medical center settings are experiencing uncertainties related to TBD recognition, diagnosis, and patient communication. These findings can inform the development of point-of-care resources to aid in patient-provider communication regarding TBDs and inform the development of continuing medical education programs for frontline and primary care providers., (© 2021. The Author(s).)

Background: We evaluated the efficiency of an ex vivo feeding technique using a silicone membrane-based feeding chamber to (i) assess the anti-feeding and acaricidal efficacy of a spot-on combination of dinotefuran, pyriproxyfen and permethrin (DPP, Vectra® 3D) against adult Ixodes scapularis and Ixodes ricinus ticks, and to (ii) explore its effect on blocking the acquisition of Borrelia burgdorferi sensu stricto., Methods: Eight purpose-bred dogs were randomly allocated to two equal-size groups based on body weight assessed on day 2. DPP was administered topically, as spot-on, to four dogs on day 0. Hair from the eight dogs was collected individually by brushing the whole body on days 2, 7, 14, 21, 28 and 35. On each day of hair collection, 0.05 g of sampled hair was applied on the membrane corresponding to each feeding unit (FU). Seventy-two FU were each seeded with 30 adults of I. scapularis (n = 24 FU) or I. ricinus ticks (n = 48 FU). Bovine blood spiked with B. burgdorferi sensu stricto (strain B31) was added into each unit and changed every 12 h for 4 days. Tick mortality was assessed 1 h after seeding. One additional hour of incubation was added for live/moribund specimens and reassessed for viability. All remaining live/moribund ticks were left in the feeders and tick engorgement status was recorded at 96 h after seeding, and the uptake of B. burgdorferi s.s. was examined in the collected ticks by applying quantitative real-time PCR., Results: Exposure to DPP-treated hair was 100% effective in blocking B. burgdorferi s.s. acquisition. The anti-feeding efficacy remained stable (100%) against both Ixodes species throughout the study. The acaricidal efficacy of DPP evaluated at 1 and 2 h after exposure was 100% throughout the study for I. ricinus, except the 1-h assessment on day 28 (95.9%) and day 35 (95.3%). The 1-h assessment of acaricidal efficacy was 100% at all time points for I. scapularis., Conclusions: The ex vivo feeding system developed here demonstrated a protective effect of DPP against the acquisition of B. burgdorferi without exposing the animals to the vectors or to the pathogen., (© 2021. The Author(s).)

Background: Lyme borreliosis (LB) is the most common vector-borne disease in Europe. Monitoring changes in the prevalence of different Borrelia species in ticks may be an important indicator of risk assessment and of differences in pathogenicity in humans. The objective of our study was to assess the prevalence, co-infection and distribution of Borrelia and Babesia species in ticks removed from humans in a large sample collected during a study period of 4 years., Methods: The ticks were collected throughout Poland from March to November over 4-year period from 2016 to 2019. All ticks (n = 1953) were morphologically identified in terms of species and developmental stage. Molecular screening for Borrelia and Babesia by amplification of the flagellin gene (flaB) or 18S rRNA marker was performed. Pathogen identity was confirmed by Sanger sequencing or PCR-restriction fragment length polymorphism analysis., Results: The ticks removed from humans in Poland during this study belonged to two species: Ixodes ricinus (97%) and Dermacentor reticulatus (3%). High Borrelia prevalence (25.3%), including B. miyamotoi (8.4%), was confirmed in Ixodes ricinus ticks removed from humans, as was the change in frequency of occurrence of Borrelia species during the 4-year study. Despite Babesia prevalence being relatively low (1.3%), the majority of tested isolates are considered to be pathogenic to humans. Babesia infection was observed more frequently among Borrelia-positive ticks (2.7%) than among ticks uninfected with Borrelia (0.8%). The most frequent dual co-infections were between Borrelia afzelii and Babesia microti. The presence of Borrelia was also confirmed in D. reticulatus (12.7%); however the role of these ticks in spirochete transmission to susceptible hosts is still unclear., Conclusions: Although the overall risk of developing LB after a tick bite is low in Europe, knowledge of the prevalence and distribution of Borrelia and Babesia species in ticks might be an important indicator of the risk of both these tick-borne diseases.

Background: The bacteria of the group Borrelia burgdorferi s.l. are the etiological agents of Lyme borreliosis in humans, transmitted by bites of ticks. Improvement of control measures requires a solid framework of the environmental traits driving its prevalence in ticks., Methods: We updated a previous meta-analysis of the reported prevalence of Borrelia burgdorferi s.l. in questing nymphs of Ixodes ricinus with a literature search from January 2010-June 2017. This resulted in 195 new papers providing the prevalence of Bb for 926 geo-referenced records. Previously obtained data (878 records, years 2000-2010) were appended for modelling. The complete dataset contains data from 82,004 questing nymphs, resulting in 558 records of B. afzelii, 404 of B. burgdorferi s.s. (only 80 after the year 2010), 552 of B. garinii, 78 of B. lusitaniae, 61 of B. spielmanii, and 373 of B. valaisiana. We associated the records with explicit coordinates to environmental conditions and to a categorical definition of European landscapes (LANMAP2) looking for a precise definition of the environmental niche of the most reported species of the pathogen, using models based on different classification methods., Results: The most commonly reported species are B. afzelii, B. garinii and B. valaisiana largely overlapping across Europe. Prevalence in ticks is associated with portions of the environmental niche. Highest prevalence occurs in areas of 280°-290° (Kelvin) of mean annual temperature experiencing a small amplitude, steady spring slope, together with high mean values and a moderate spring rise of vegetation vigor. Low prevalence occurs in sites with low and a noteworthy annual amplitude of temperature and the Normalized Difference Vegetation Index (colder areas with abrupt annual changes of vegetation). Models based on support vector machines provided a correct classification rate of the habitat and prevalence of 89.5%. These results confirm the association of prevalence of the three most commonly reported species of B. burgdorferi s.l. in Europe to parts of the environmental niche and provide a statistically tractable framework for analyzing trends under scenarios of climate change.

Background: Birds can act as reservoirs of tick-borne pathogens and can also disperse pathogen-containing ticks to both nearby and remote localities. The aims of this study were to estimate tick infestation patterns on migratory birds and the prevalence of different Borrelia species and tick-borne encephalitis virus (TBEV) in ticks removed from birds in south-eastern Sweden., Methods: Ticks were collected from resident and migratory birds captured at the Ottenby Bird Observatory, Öland, Sweden, from March to November 2009. Ticks were molecularly identified to species, and morphologically to developmental stage, and the presence of Borrelia bacteria and TBEV was determined by quantitative real-time PCR., Results: A total of 1339 ticks in the genera Haemaphysalis, Hyalomma, and Ixodes was recorded of which I. ricinus was the most abundant species. Important tick hosts were the European robin (Erithacus rubecula), Blackbird (Turdus merula), Tree pipit (Anthus trivialis), Eurasian wren (Troglodytes troglodytes), Common redstart (Phoenicurus phoenicurus), Willow warbler (Phylloscopus trochilus), and Common whitethroat (Sylvia communis). Borrelia bacteria were detected in 25% (285/1,124) of the detached ticks available for analysis. Seven Borrelia species (B. afzelii, B. burgdorferi (s.s.), B. garinii, B. lusitaniae, B. turdi, B. valaisiana, and B. miyamotoi) were identified. B. turdi was recorded for the first time in ticks in Sweden. The number of Borrelia cells per tick ranged from 2.0 × 10 0 to 7.0 × 10 5 . B. miyamotoi-containing ticks contained a significantly higher median number of Borrelia cells than B. burgdorferi (s.l.)-containing ticks. B. garinii and B. miyamotoi were the most prevalent Borrelia species in tick larvae. Larvae of I. ricinus with B. garinii were removed from seven bird species, particularly S. communis and A. trivialis, which may suggest that the larvae had contracted the Borrelia bacteria from or via these birds. Also, a high percentage of tick larvae containing B. miyamotoi was removed from E. rubecula. All ticks were negative for TBEV., Conclusions: The results corroborate the view that the contributions of birds to human disease are substantial, particularly as blood hosts for ticks and for their short-, medium-, and long-distance dispersal. Moreover, several ground-foraging bird species appear to be important for the maintenance and dispersal of Borrelia species. The absence of TBEV in the ticks conforms to other similar studies.

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.

Background: Urban green spaces are important for human health, but they may expose visitors to tick-borne diseases. This not only presents a potential public health challenge but also undermines the expected public health gains from urban green spaces. The aim of this study is to assess the public health risk of tick-borne diseases in an urban green space used for recreation in Stockholm, Sweden. Methods: We used a mixed method approach identifying both the magnitude of the tick hazard and the extent of the human exposure to tick-borne diseases. At six entry points to an urban green space, we sampled ticks and documented microhabitat conditions from five randomly assigned 2 m × 2 m plots. Surrounding habitat data was analyzed using geographical information system (GIS). Nymphs and adult ticks were tested for Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum using TaqMan qPCR. Positive B. burgdorferi (s.l.) ticks were further analyzed by nested PCR amplification and sequence analysis. Population census data and visitor count data were used to estimate the degree of human exposure to tick-borne diseases. To further understand the degree to which visitors get in contact with infected ticks we also conducted interviews with visitors to green spaces. Results: High tick densities were commonly found in humid broadleaved forest with low field vegetation. High pathogen prevalence was significantly correlated with increasing proportions of artificial areas. Integrating the tick hazard with human exposure we found that the public health risk of tick-borne diseases was moderate to high at most of the studied entry points. Many of the visitors frequently used urban green spaces. Walking was the most common activity, but visitors also engaged in activities with higher risk for tick encounters. Individual protective measures were connected to specific recreational activities such as picking berries or mushrooms. Conclusions: The number of visitors can be combined with tick inventory data and molecular analyses of pathogen prevalence to make crude estimations of the public health risk of tick-borne diseases in urban green spaces. The risk of encountering infected ticks is omnipresent during recreational activities in urban green spaces, highlighting the need for public health campaigns to reduce the risk of tick-borne diseases. [ABSTRACT FROM AUTHOR]

Background: Borrelia burgdorferi (sensu lato) and rickettsiae of the spotted fever group are zoonotic tick-borne pathogens. While small mammals are confirmed reservoirs for certain Borrelia spp., little is known about the reservoirs for tick-borne rickettsiae. Between 2012 and 2014, ticks were collected from the vegetation and small mammals which were trapped in Saxony, Germany. DNA extracted from ticks and the small mammals' skin was analyzed for the presence of Rickettsia spp. and B. burgdorferi (s.l.) by qPCR targeting the gltA and p41 genes, respectively. Partial sequencing of the rickettsial ompB gene and an MLST of B. burgdorferi (s.l.) were conducted for species determination., Results: In total, 673 small mammals belonging to eight species (Apodemus agrarius, n = 7; A. flavicollis, n = 214; Microtus arvalis, n = 8; Microtus agrestis, n = 1; Mustela nivalis, n = 2; Myodes glareolus, n = 435; Sorex araneus, n = 5; and Talpa europaea, n = 1) were collected and examined. In total, 916 questing ticks belonging to three species (Ixodes ricinus, n = 741; Dermacentor reticulatus, n = 174; and I. trianguliceps, n = 1) were collected. Of these, 474 ticks were further investigated. The prevalence for Rickettsia spp. and B. burgdorferi (s.l.) in the investigated small mammals was 25.3 and 31.2%, respectively. The chance of encountering Rickettsia spp. in M. glareolus was seven times higher for specimens infested with D. reticulatus than for those which were free of D. reticulatus (OR: 7.0; 95% CI: 3.3-14.7; P < 0.001). In total, 11.4% of questing I. ricinus and 70.5% of D. reticulatus were positive for Rickettsia spp. DNA of B. burgdorferi (s.l.) was detected only in I. ricinus (5.5%). Sequence analysis revealed 9 R. helvetica, 5 R. raoultii, and 1 R. felis obtained from 15 small mammal samples., Conclusion: Small mammals may serve as reservoirs for Rickettsia spp. and B. burgdorferi (s.l.). While the prevalence for Rickettsia spp. in M. glareolus is most likely depending on the abundance of attached D. reticulatus, the prevalence for B. burgdorferi (s.l.) in small mammals is independent of tick abundance. Dermacentor reticulatus may be the main vector of certain Rickettsia spp. but not for Borrelia spp.

Background: As tick ranges expand across North America, the risk of tick bites and tick-borne diseases (TBDs, i.e. diseases or syndromes associated with ticks) rises for humans and animals, making prevention critical. Several U.S. studies have examined knowledge, attitudes, and practices regarding ticks and TBDs for various cohorts of people. However, among occupational groups with high exposure risk from ticks and TBDs are livestock producers, of which we know little about. To help address this gap, an electronic questionnaire was distributed to livestock producers in Ohio, U.S, a state with a robust agricultural sector. Methods: We generated descriptive statistics and conducted a multiple correspondence analysis followed by hierarchical clustering on principal components to identify producers with similar response profiles. Results: Responses from 57 producers showed that most (52.6%) think the American dog tick (Dermacentor variabilis) is found in Ohio but are unsure about other species. Although several TBDs are present in Ohio, most (> 50%) producers were unsure or unaware of their presence. Interestingly, most (54.4%) thought ticks pose major health risks for their livestock but fewer (49.1%) thought the same for humans. Regardless, most producers did employ at least one prevention method for themselves (96.5%) and their animals (82.5%). Cluster analysis (n = 48) identified three groups: the largest (n = 21) was considered "aware and cautious" consisting primarily of farm owners. The others generally practiced less prevention and consisted primarily of farm employees. Conclusions: Our findings indicate that producers in Ohio practice prevention for themselves and their livestock, but demonstrate gaps in knowledge (e.g., TBD occurrence) and attitudes (e.g., health risks) that could be addressed via educational formats we found producers preferred (e.g., extension materials), to encourage informed prevention. This is especially important for farm employees that may practice less prevention because of lower awareness. Our study can guide others in regions faced with similar tick and TBD risks to protect occupational and livestock health. [ABSTRACT FROM AUTHOR]

Background: Lyme borreliosis (LB), caused by Borrelia burgdorferi sensu lato (Bbsl), is the most common tick-borne disease in Europe. Although public health surveillance for LB has been conducted in Romania since 2007, the extent of under-detection of Bbsl infections by LB surveillance has not been estimated. We therefore estimated the under-detection of symptomatic Bbsl infections by LB surveillance to better understand the LB burden in Romania., Methods: The number of incident symptomatic Bbsl infections were estimated from a seroprevalence study conducted in six counties (population 2.3 M) and estimates of the symptomatic proportion and duration of persistence of anti-Bbsl immunoglobulin G (IgG) antibodies. The number of incident symptomatic Bbsl infections were compared with the number of surveillance-reported LB cases to derive an under-detection multiplier, and then the under-detection multiplier was applied to LB surveillance data to estimate the incidence of symptomatic Bbsl infection from 2018 to 2023., Results: We estimate that there were 1968 individuals with incident symptomatic Bbsl infection in the six counties where the seroprevalence study was conducted in 2020, compared with the 187 surveillance-reported LB cases, resulting in an under-detection multiplier of 10.5 (i.e., for every surveillance-reported LB case, there were 10.5 symptomatic incident Bbsl infections). The incidence of symptomatic Bbsl infection in the six counties was 86.9/100,000 population in 2023, similar to the incidence in 2018-2020 (86.0) and higher than in 2021-2022 (40.3)., Conclusions: There is a higher incidence of symptomatic Bbsl infection than is reported through public health surveillance for LB in Romania. Additional efforts are needed to strengthen disease prevention and address the important public health problem of LB., (© 2024. The Author(s).)

Background: The number of Lyme disease risk areas in Canada is growing. In regions with emerging tick populations, it is important to emphasize peridomestic risk and the importance of protective behaviours in local public health communication. This study aims to identify characteristics associated with high levels of Lyme disease knowledge and adoption of protective behaviours among residents in the Ottawa, Ontario region., Methods: A geographically stratified web survey was conducted in November 2020 (n = 2018) to determine knowledge, attitudes, and practices regarding Lyme disease among adult residents. Responses were used to calculate: (i) composite scores for knowledge and adoption of protective practices; and (ii) an exposure risk index based on reported activity in woodlands during the spring-to-fall tick exposure risk period., Results: 60% of respondents had a high knowledge of Lyme disease, yet only 14% indicated they often use five or more measures to protect themselves. Factors strongly associated with a high level of Lyme disease knowledge included being 55 or older (Odds Ratio (OR) = 2.04), living on a property with a yard (OR = 3.22), having a high exposure index (OR = 1.59), and knowing someone previously infected with Lyme disease (OR = 2.05). Strong associations with the adoption of a high number of protective behaviours were observed with membership in a non-Indigenous racialized group (OR = 1.70), living on a property with a yard (OR = 2.37), previous infection with Lyme disease (OR = 2.13), prior tick bite exposure (OR = 1.62), and primarily occupational activity in wooded areas (OR = 2.31)., Conclusions: This study highlights the dynamics between Lyme disease knowledge, patterns of exposure risk awareness, and vigilance of personal protection in a Canadian region with emerging Lyme disease risk. Notably, this study identified gaps between perceived local risk and protective behaviours, presenting opportunities for targeted enhanced communication efforts in areas of Lyme disease emergence., (© 2024. The Author(s).)

Background: Lyme disease control strategies may include tick control interventions in high risk areas. Public authorities may be interested to assess how these types of interventions are perceived by the public which may then impact their acceptability. The aims of this paper are to compare socio-cognitive factors associated with high acceptability of tick control interventions and to describe perceived issues that may explain their low acceptability in populations living in two different regions, one being an endemic region for LD since the last 30 years, the Neuchâtel canton, in Switzerland, and another where the disease is emerging, the Montérégie region, in Canada., Methods: A mixed methods' design was chosen. Quantitative data were collected using web-surveys conducted in both regions (n = 814). Multivariable logistic regressions were used to compare socio-cognitive factors associated with high acceptability of selected interventions. Qualitative data were collected using focus group's discussions to describe perceived issues relative to these interventions., Results: Levels of acceptability in the studied populations were the lowest for the use of acaricides and landscaping and were under 50 % in both regions for six out of eight interventions, but were higher overall in Montérégie. High perceived efficacy of the intervention was strongly associated with high acceptability of tick control interventions. A high perceived risk about LD was also associated with a high acceptability of intervention under some models. High level of knowledge about LD was negatively associated with high acceptability of the use of acaricides in Neuchâtel. Perceived issues explaining low acceptability included environmental impacts, high costs to the public system, danger of individual disempowerment and perceptions that tick control interventions were disproportionate options for the level of LD risk., Conclusion: This study suggests that the perceived efficacy and LD risk perception may be key factors to target to increase the acceptability of tick control interventions. Community-level issues seem to be important considerations driving low acceptability of public health interventions. Results of this study highlight the importance for decision-makers to account for socio-cognitive factors and perceived issues that may affect the acceptability of public health interventions in order to maximize the efficacy of actions to prevent and control LD.

Background: Ticks are major vectors of diseases affecting humans such as Lyme disease or domestic animals such as anaplasmosis. Cross-alteration of the vertebrate host skin microbiome and the tick microbiome may be essential during the process of tick feeding and for the mechanism of pathogen transmission. However, it has been poorly investigated. Methods: We used mice bitten by field-collected ticks (nymphs and adult ticks) in different experimental conditions to investigate, by 16S rRNA gene metabarcoding, the impact of blood feeding on both the mouse skin microbiome and the tick microbiome. We also investigated by PCR and 16S rRNA gene metabarcoding, the diversity of microorganisms transmitted to the host during the process of tick bite at the skin interface and the dissemination of the pathogen in host tissues (blood, heart, and spleen). Results: Most of the commensal bacteria present in the skin of control mice were replaced during the blood-feeding process by bacteria originating from the ticks. The microbiome of the ticks was also impacted by the blood feeding. Several pathogens including tick-borne pathogens (Borrelia/Borreliella, Anaplasma, Neoehrlichia, Rickettsia) and opportunistic bacteria (Williamsia) were transmitted to the skin microbiome and some of them disseminated to the blood or spleen of the mice. In the different experiments of this study, skin microbiome alteration and Borrelia/Borreliella transmission were different depending on the tick stages (nymphs or adult female ticks). Conclusions: Host skin microbiome at the bite site was deeply impacted by the tick bite, to an extent which suggests a role in the tick feeding, in the pathogen transmission, and a potentially important impact on the skin physiopathology. The diversified taxonomic profiles of the tick microbiome were also modified by the blood feeding. FNmPmXVvH5C8zJYmhgJpvu Video Abstract [ABSTRACT FROM AUTHOR]

Background: To predict the risk of tick-borne disease, it is critical to understand the ecological factors that determine the abundance of ticks. In Europe, the sheep tick (Ixodes ricinus) transmits a number of important diseases including Lyme borreliosis. The aim of this long-term study was to determine the abiotic and biotic factors driving the annual abundance of I. ricinus at a location in Switzerland where Lyme borreliosis is endemic., Methods: Over a 15-year period (2004 to 2018), we monitored the abundance of I. ricinus ticks on a monthly basis at three different elevations on Chaumont Mountain in Neuchâtel, Switzerland. We collected climate variables in the field and from nearby weather stations. We obtained data on beech tree seed production from the literature, as the abundance of Ixodes nymphs can increase dramatically two years after a masting event. We used AIC-based model selection to determine which ecological variables drive annual variation in tick density., Results: We found that elevation site, year, seed production by beech trees two years prior, and mean annual relative humidity together explained 73.2% of the variation in our annual estimates of nymph density. According to the parameter estimates of our models, (i) the annual density of nymphs almost doubled over the 15-year study period, (ii) changing the beech tree seed production index from very poor mast (1) to full mast (5) increased the abundance of nymphs by 86.2% two years later, and (iii) increasing the field-collected mean annual relative humidity from 50.0 to 75.0% decreased the abundance of nymphs by 46.4% in the same year. Climate variables collected in the field were better predictors of tick abundance than those from nearby weather stations indicating the importance of the microhabitat., Conclusions: From a public health perspective, the increase in nymph abundance is likely to have increased the risk of tick-borne disease in this region of Switzerland. Public health officials in Europe should be aware that seed production by deciduous trees is a critical driver of the abundance of I. ricinus, and hence the risk of tick-borne disease.

Background: Both incidence and geographical range of tick-borne disease has increased across the USA. Similar to people, dogs are hosts for Anaplasma spp., Babesia spp., Ehrlichia spp. and Borrelia burgdorferi. Dogs also share our homes and beds, making them both a sentinel for the ticks in our backyards but also increasing our exposure to ticks. Measures to better track, prevent, and/or treat tick-borne diseases in companion animals can lead to better control and prevention of human tick-borne disease. This study identifies demographic and co-infection risk factors for canine seropositivity to tick-borne infections in a cohort of hunting dogs across the USA., Results: Human patterns of tick-borne disease co-infection in the USA have been predominantly driven by the geographical distribution of the tick vector. Dogs who tested seropositive for Anaplasma spp. were 1.40 times more likely (P = 0.0242) to also test seropositive for Babesia spp. and vice versa (1.60 times more likely, P = 0.0014). Dogs living in the West had 5% lower risk (P = 0.0001) for Ehrlichia spp. seropositivity compared to other regions. Controlling for age and Anaplasma spp. seroprevalence, dogs in all three other regions were 2.30 times more likely (P = 0.0216) to test seropositive for B. burgdorferi than dogs in the West. Dogs seropositive for B. burgdorferi were 1.60 times more likely (P = 0.0473) to be seropositive for Anaplasma spp., Conclusions: Tick geographical distributions have a prominent impact on the regional distribution of hunting dog exposure to tick-borne diseases. Education concerning regional tick prevalence and disease risk is important for everyone, but particularly dog owners, regarding ticks in their region and protection from infection and co-infection of tick-borne pathogens as they travel or move with their dogs. Dogs are sentinel species for human exposure to ticks, and as such surveillance of canine tick-borne infections and understanding the probability that these infections might be seen together as co-infections helps predict emerging areas where people are more likely to be exposed as well.

Background: The increased incidence of Lyme disease in Europe necessitates permanent monitoring of the occurrence and activity of its vector. Therefore, in this study, we have investigated the presence and seasonal activity of Ixodes ricinus ticks in various habitats of a large industrial region in south-western Poland in correlation with environmental factors present in urban heat islands. Additionally, the risk of borreliosis in this part of Poland has been assessed., Methods: The investigations were carried out at two-week intervals between April and October 2001 and 2002. Ticks were collected from four localities in Upper Silesia, i.e. in a city park (CH), on the outskirts of two large cities (KO, MI), and in a forest (KL). We analysed the impact of temperature and humidity measured during the collection period in the I. ricinus habitats, the climatic conditions prevailing in the study area, and the degree of environmental contamination on the abundance and activity of these ticks in the respective sites. The degree of borreliosis risk in the region was determined on the basis of the results of research on the prevalence of Borrelia burgdorferi s.l. in ticks and reports from sanitary-epidemiological stations., Results: In total, 2061 I. ricinus ticks, including 606 nymphs and 1455 adults, were collected in the study area. The number and activity of the ticks varied during the collection in the different sites. In the urban locality CH, tick abundance was the lowest (455 throughout the investigation period), and the seasonal activity of females was unimodal and persisted for as long as 4 months. In the suburban localities KO and MI, tick abundance was higher (485 and 481 specimens, respectively) and the activity of females was unimodal. The highest abundance (640 ticks) and a bimodal pattern of female activity were reported from the forest locality KL. In all the localities, the activity of nymphs was unimodal. Humidity was found to be a factor influencing I. ricinus abundance and activity, whereas temperature did not affect their number and behaviour significantly. The climate parameters within the urban heat islands noted during the investigations contributed to dispersal of dust and gas pollutants. The analysis of the data reveals that there is a risk of borreliosis in the entire study area; however, it is higher in the urban localities than in the suburban sites., Conclusions: Environmental conditions (habitat, climate, and dust and gas pollution) prevailing within urban heat islands may exert an impact on tick abundance and activity and the prevalence of Lyme disease in the study area. The greatest effect of the environmental factors on ticks was found in the city park, where the risk of human infection with B. burgdorferi s.l. spirochetes is the highest as well.

Background: After antibiotic treatment of Lyme borreliosis, a subset of patients report persistent symptoms, also referred to as post-treatment Lyme disease syndrome. The reported prevalence of persistent symptoms varies considerably, and its pathophysiology is under debate. The LymeProspect study has been designed to investigate the prevalence, severity, and a wide range of hypotheses on the etiology of persistent symptoms among patients treated for Lyme borreliosis in the Netherlands., Methods: LymeProspect is a prospective, observational cohort study among adults with proven or probable Lyme borreliosis, either erythema migrans or disseminated manifestations, included at the start of antibiotic treatment. During one year of follow-up, participants are subjected to questionnaires every three months and blood is collected repeatedly during the first three months. The primary outcome is the prevalence of persistent symptoms after treatment, assessed by questionnaires online focusing on fatigue (CIS, subscale fatigue severity), pain (SF-36, subscale pain) and neurocognitive dysfunction (CFQ). Potential microbiological, immunological, genetic, epidemiological and cognitive-behavioral determinants for persistent symptoms are secondary outcome measures. Control cohorts include patients with long-lasting symptoms and unconfirmed Lyme disease, population controls, and subjects having reported a tick bite not followed by Lyme borreliosis., Discussion: This article describes the background and design of the LymeProspect study protocol. This study is characterized by a prospective, explorative and multifaceted design. The results of this study will provide insights into the prevalence and determinants of persistent symptoms after treatment for Lyme borreliosis, and may provide a rationale for preventive and treatment recommendations., Trial Registration: NTR4998 (Netherlands Trial Register). Date of registration: 13 February 2015.

Background: Many pathogens and parasites can infect multiple host species, and the competence of different hosts as pathogen reservoirs is key to understanding their epidemiology. Small mammals are important hosts for the instar stages of Ixodes ricinus ticks, the principal vector of Lyme disease in Europe. Small mammals also act as reservoirs of Borrelia afzelii, the most common genospecies of the Borrelia burgdorferi sensu lato (s.l.) spirochetes causing Lyme disease in Europe. However, we lack quantitative estimates on whether different small mammal species are equally suitable hosts for feeding I. ricinus and whether they show differences in pathogen transmission from host to tick., Methods: Here, we analysed the feeding success and prevalence of B. burgdorferi s.l. infections in 12,987 instar I. ricinus found on captured small mammals with known infection status in Norway (2018-2022)., Results: We found that larvae were more likely to acquire a blood meal from common shrews (Sorex araneus, 46%) compared to bank voles (Myodes glareolus, 36%) and wood mice (Apodemus sylvaticus, 31%). Nymphs tended to be more likely to acquire a blood meal from wood mice (66%) compared to bank voles (54%). Common shrews harboured few nymphs (n=19). Furthermore, we found that larvae feeding on infected bank voles (11%) were more likely to be infected with B. burgdorferi s.l. than larvae on infected common shrews (7%) or wood mice (4%)., Conclusions: Our study provides quantitative evidence of differences in suitability for the instar stages of I. ricinus across taxa of small mammals and highlights how even known small mammal host species can differ in their ability to feed ticks and infect larval ticks with the pathogen causing Lyme disease., (© 2024. The Author(s).)

Background: The present study investigated the prevalence of Borrelia burgdorferi sensu lato (s.l.) genospecies in Ixodes ricinus ticks collected in Hanover, Northern Germany, in 2010. At the same time the study served as fifth-year-follow-up study for data comparison with 2005., Methods: A total of 2100 questing ticks were collected and analysed by quantitative real-time PCR (qPCR) with subsequent species differentiation via Reverse Line Blot and Sanger sequencing. Simultaneously, results obtained in 2010 were compared to infection rates from 2005 to evaluate the development of B. burgdorferi s.l. infection rates in Hanoverian ticks., Results: Overall, 22.7% (476/2,100) of collected ticks were tested positive for B. burgdorferi s.l. infections. Adult ticks showed an infection rate of 33.3% (124/372), subdivided into 29.6% (58/196) positive males and 37.5% (66/176) positive females. Nymph and larvae infection rates were found to be 20.3% (344/1,697) and 25.8% (8/31), respectively. Species identification was successful for 59.2% (282/476) of positive ticks with B. afzelii as the most frequently detected genospecies, followed by B. garinii (including B. bavariensis) and B. spielmanii. B. burgdorferi sensu stricto (s.s.), B. bissettii, B. valaisiana and B. lusitaniae were also identified. Significant differences concerning seasonal fluctuations as well as local differences were observed. Comparing infection rates of Hanoverian ticks between years, a significant increase (P = 0.002) could be observed for larvae with 1.7% positives (2/60) in 2005 and 25.8% positives (8/31) in 2010. In the latter year, coinfections with Borrelia and Rickettsiales were detected in a total of 7.8% (163/2,100) of collected ticks. Of these, 7.3% (153/2,100) were coinfected with Rickettsia spp., 0.3% (7/2,100) with A. phagocytophilum and 0.1% (3/2,100) were coinfected with all three pathogens. Between years 2005 and 2010, no statistically significant differences in coinfection rates were found., Conclusions: Comparing B. burgdorferi s.l. infections in Hanoverian I. ricinus ticks in 2010 with data from 2005, a statistically significant increase of infected larvae was noted, whereas the other stages revealed no statistically significant differences. Whether the increased larvae infection rate is an isolated event or results from factual circumstances, e.g. increasing effectiveness of transovarial transmission due to unknown factors, has to be evaluated in further studies.

Background: Severe fever with thrombocytopenia syndrome (SFTS), caused by the SFTS virus (SFTSV), is an acute infectious disease transmitted by ticks that has recently been identified. There are no reports of epidemic serotypes in Liaoning Province, PR China. The aim of this study was, therefore, to identify genotypes of SFTSV in this province. Methods: In 2019, quantitative PCR testing was performed on 17 patients suspected of being infected with SFTS in Liaoning Province and on 492 ticks from the counties and cities surrounding the patients' residences. Four samples were subjected to virus isolation and whole-genome amplification. Results: Molecular diagnostic results confirmed SFTSV infection in five of the 17 suspected cases of SFTS and in 12 of the 492 ticks, with a prevalence of 2.4%. Four strains of SFTSV were successfully isolated from patients' blood and ticks. Phylogenetic analysis after whole-genome amplification and sequencing showed that they all belonged to genotype A of SFTSV. Conclusions: This study is the first to determine the genotype of SFTSV in patients and ticks in Liaoning Province, PR China. The results deepen our understanding of the SFTS epidemic and provide information on the variability in mortality rate among genotypes. [ABSTRACT FROM AUTHOR]

Malaria and Lyme disease were the largest vector-borne epidemics in recent US history. Malaria, a mosquito-borne disease with intense transmission, had higher morbidity and mortality, whereas Lyme and other tick-borne diseases are more persistent in the environment. The responses to these two epidemics were markedly different. The anti-malaria campaign involved large-scale public works eradicating the disease within two decades. In contrast, Lyme disease control and prevention focused on the individual, advocating personal protection and backyard control, with the disease incidence steeply increasing since 1980s. Control of Lyme and other tick-borne diseases will require a paradigm shift emphasizing measures to reduce tick and host (deer) populations and a substantial R&D effort. These steps will require changing the political climate, perceptions and opinions to generate support among governmental levels and the general public. Such support is essential for providing a real solution to one of the most intractable contemporary public health problems.

Background: Lyme borreliosis (LB) is the most commonly reported vector-borne disease in north temperate regions worldwide, affecting an estimated 300,000 people annually in the United States alone. The incidence of LB is correlated with human exposure to its vector, the blacklegged tick (Ixodes scapularis). To date, attempts to model tick encounter risk based on environmental parameters have been equivocal. Previous studies have not considered (1) the differences between relative humidity (RH) in leaf litter and at weather stations, (2) the RH threshold that affects nymphal blacklegged tick survival, and (3) the time required below the threshold to induce mortality. We clarify the association between environmental moisture and tick survival by presenting a significant relationship between the total number of tick adverse moisture events (TAMEs - calculated as microclimatic periods below a RH threshold) and tick abundance each year., Methods: We used a 14-year continuous statewide tick surveillance database and corresponding weather data from Rhode Island (RI), USA, to assess the effects of TAMEs on nymphal populations of I. scapularis. These TAMEs were defined as extended periods of time (>8 h below 82% RH in leaf litter). We fit a sigmoid curve comparing weather station data to those collected by loggers placed in tick habitats to estimate RH experienced by nymphal ticks, and compiled the number of historical TAMEs during the 14-year record., Results: The total number of TAMEs in June of each year was negatively related to total seasonal nymphal tick densities, suggesting that sub-threshold humidity episodes >8 h in duration naturally lowered nymphal blacklegged tick abundance. Furthermore, TAMEs were positively related to the ratio of tick abundance early in the season when compared to late season, suggesting that lower than average tick abundance for a given year resulted from tick mortality and not from other factors., Conclusions: Our results clarify the mechanism by which environmental moisture affects blacklegged tick populations, and offers the possibility to more accurately predict tick abundance and human LB incidence. We describe a method to forecast LB risk in endemic regions and identify the predictive role of microclimatic moisture conditions on tick encounter risk.

Background: Understanding the variation in prevalence of Borrelia burgdorferi sensu lato (Lyme Borreliosis Spirochaetes, LBS) and Anaplasma phagocytophilum (causing tick-borne fever in ruminants and human granulocytic ehrlichiosis) in ticks is vital from both a human and an animal disease perspective to target the most effective mitigation measures. From the host competence hypothesis, we predicted that prevalence of LBS would decrease with red deer density, while prevalence of A. phagocytophilum would increase., Methods: Based on a sample of 112 adult and 686 nymphal Ixodes ricinus ticks collected with flagging during questing from 31 transects (4-500 m long) corresponding to individual seasonal home ranges of 41 red deer along the west coast of Norway, we tested whether there were spatial and seasonal variations in prevalence with a special emphasis on the population density of the most common large host in this area, the red deer (Cervus elaphus). We used a multiplex real-time PCR assay for detection of A. phagocytophilum and LBS., Results: Prevalence of LBS was higher in adult female ticks (21.6%) compared to adult male ticks (11.5%) and nymphs (10.9%), while prevalence was similar among stages for prevalence of A. phagocytophilum (8.8%). Only partly consistent with predictions, we found a lower prevalence of LBS in areas of high red deer density, while there was no relationship between red deer density and prevalence of A. phagocytophilum in ticks. Prevalence of both bacteria was much higher in ticks questing in May compared to August., Conclusions: Our study provides support to the notion that spatial variation in host composition forms a role for prevalence of LBS in ticks also in a northern European ecosystem, while no such association was found for A. phagocytophilum. Further studies are needed to fully understand the similar seasonal pattern of prevalence of the two pathogens.

Background: In Mongolia, the taiga tick Ixodes persulcatus is the major vector of tick-borne pathogens. Knowledge about co-infections of these pathogens in ticks is necessary both for understanding their persistence in nature and for diagnosing and treating tick-borne diseases. Methods: The prevalence of seven tick-borne infections in 346 I. persulcatus collected from the Selenge and Bulgan provinces of Mongolia was evaluated using real-time PCR. Quantification of Borrelia spp. was performed using multiplex quantitative PCR targeting the 16S rRNA gene. Genetic analysis of Borrelia spp. in 11 ticks infected with Borrelia miyamotoi, including six ticks co-infected with Borrelia burgdorferi sensu lato (s.l.), was performed by high-throughput sequencing of the flaB gene fragment. Results: Six ticks (1.7%) were infected with tick-borne encephalitis virus (TBEV); 171 (49.4%), with B. burgdorferi sensu lato; 17 (4.9%), with B. miyamotoi; 47 (13.6%), with Anaplasma phagocytophilum; and 56 (16.2%), with Ehrlichia sp. Neither Rickettsia sibirica nor R. heilongjiangensis were detected. Borrelia burgdorferi s.l. occurred as co-infection in 55 (32.2%) of all infected ticks. The other pathogens co-infected ticks in 58.8–70.2% of cases. No pairwise associations between co-infecting pathogens were observed, with the exception of a positive association between A. phagocytophilum and Ehrlichia sp. infections. The spirochete loads of B. miyamotoi were significantly higher than those of B. burgdorferi s.l. (mean: 5.2 vs 4.0 log10 genome copies/tick, respectively). Ten isolates of B. miyamotoi belonged to the Siberian lineage. Borrelia burgdorferi s.l was represented by nine isolates of B. afzelii, B. bavariensis and B. garinii. Conclusions: In populations of I. persulcatus inhabiting the Selenge and Bulgan provinces of Mongolia, five vector-borne pathogens, i.e. TBEV, B. burgdorferi s.l., B. miyamotoi, A. phagocytophilum and Ehrlichia sp., persist independently from each other, with the exception of A. phagocytophilum and Ehrlichia sp. which seem to share the circulation mode. The discrepancies in B. burgdorferi s.l. and B. miyamotoi prevalence and spirochete load per tick suggest that different ecological niches are occupied by Lyme disease and relapsing fever agents. High-throughput sequencing allows genetic identification of borreliae species in co-infected ticks. [ABSTRACT FROM AUTHOR]

Introduction: To answer to patients' medical wandering, often due to "unexplained symptoms" of "unexplained diseases" and to misinformation, multidisciplinary care centers for suspected Lyme borreliosis (LB), such as the 5 Tick-Borne Diseases (TBDs) Reference Centers (TBD-RC), were created a few years ago in France, the Netherlands and Denmark. Our study consisted of a comprehensive analysis of the satisfaction of the patients managed at a TBD-RC for suspected LB in the context of scientific and social controversy., Methods: We included all adults who were admitted to one of the TBD-RC from 2017 to 2020. A telephone satisfaction survey was conducted 12 months after their first consultation. It consisted of 5 domains, including 2 free-text items: "What points did you enjoy?" and "What would you like us to change or to improve?". In the current study, the 2 free-items were analyzed with a qualitative method called reflexive thematic analysis within a semantic and latent approach., Results: The answer rate was 61.3% (349/569) and 97 distinctive codes from the 2-free-text items were identified and classified into five themes: (1) multidisciplinarity makes it possible to set up quality time dedicated to patients; (2) multidisciplinarity enables seamless carepaths despite the public hospital crisis compounded by the COVID-19 pandemic; (3) multidisciplinarity is defined as trust in the team's competences; (4) an ambivalent opinion and uncertainty are barriers to acceptance of the diagnosis, reflecting the strong influence of the controversy around LB; and (5) a lack of adapted communication about TBDs, their management, and ongoing research is present., Conclusion: The multidisciplinary management for suspected LB seemed an answer to medical wandering for the majority of patients and helped avoid misinformation, enabling better patient-centered shared information and satisfaction, despite the context of controversy., (© 2024. The Author(s).)

Background: Genetic variation underly inter-individual variation in host immune responses to infectious diseases, and may affect susceptibility or the course of signs and symptoms., Methods: We performed genome-wide association studies in a prospective cohort of 1138 patients with physician-confirmed Lyme borreliosis (LB), the most common tick-borne disease in the Northern hemisphere caused by the bacterium Borrelia burgdorferi sensu lato. Genome-wide variants in LB patients-divided into a discovery and validation cohort-were compared to two healthy cohorts. Additionally, ex vivo monocyte-derived cytokine responses of peripheral blood mononuclear cells to several stimuli including Borrelia burgdorferi were performed in both LB patient and healthy control samples, as were stimulation experiments using mechanistic/mammalian target of rapamycin (mTOR) inhibitors. In addition, for LB patients, anti-Borrelia antibody responses were measured. Finally, in a subset of LB patients, gene expression was analysed using RNA-sequencing data from the ex vivo stimulation experiments., Results: We identified a previously unknown genetic variant, rs1061632, that was associated with enhanced LB susceptibility. This polymorphism was an eQTL for KCTD20 and ETV7 genes, and its major risk allele was associated with upregulation of the mTOR pathway and cytokine responses, and lower anti-Borrelia antibody production. In addition, we replicated the recently reported SCGB1D2 locus that was suggested to have a protective effect on B. burgdorferi infection, and associated this locus with higher Borrelia burgdorferi antibody indexes and lower IL-10 responses., Conclusions: Susceptibility for LB was associated with higher anti-inflammatory responses and reduced anti-Borrelia antibody production, which in turn may negatively impact bacterial clearance. These findings provide important insights into the immunogenetic susceptibility for LB and may guide future studies on development of preventive or therapeutic measures., Trial Registration: The LymeProspect study was registered with the International Clinical Trials Registry Platform (NTR4998, registration date 2015-02-13)., (© 2024. The Author(s).)

Background: Performing a tick check after visiting nature is considered the most important preventive measure to avoid contracting Lyme disease. Checking the body for ticks after visiting nature is the only measure that can fully guarantee whether one has been bitten by a tick and provides the opportunity to remove the tick as soon as possible, thereby greatly reducing the chance of contracting Lyme disease. However, compliance to performing the tick check is low. In addition, most previous studies on determinants of preventive measures to avoid Lyme disease lack a clear definition and/or operationalization of the term "preventive measures". Those that do distinguish multiple behaviors including the tick check, fail to describe the systematic steps that should be followed in order to perform the tick check effectively. Hence, the purpose of this study was to identify determinants of systematically performing the tick check, based on social cognitive theory., Methods: A cross-sectional self-administered survey questionnaire was filled out online by 508 respondents (M age  = 51.7, SD = 16.0; 50.2% men; 86.4% daily or weekly nature visitors). Bivariate correlations and multivariate regression analyses were conducted to identify associations between socio-cognitive determinants (i.e. concepts related to humans' intrinsic and extrinsic motivation to perform certain behavior), and the tick check, and between socio-cognitive determinants and proximal goal to do the tick check., Results: The full regression model explained 28% of the variance in doing the tick check. Results showed that performing the tick check was associated with proximal goal (β = .23, p < 0.01), self-efficacy (β = .22, p < 0.01), self-evaluative outcome expectations (β = .21, p < 0.01), descriptive norm (β = .16, p < 0.01), and experience (β = .13, p < 0.01)., Conclusions: Our study is among the first to examine the determinants of systematic performance of the tick check, using an extended version of social cognitive theory to identify determinants. Based on the results, a number of practical recommendations can be made to promote the performance of the tick check.

Background: Anaplasmataceae and Borrelia burgdorferi s.l. are important tick-borne bacteria maintained in nature by transmission between ticks and vertebrate hosts. However, the potential role of lizards as hosts has not been sufficiently studied., Results: The current study showed that 23 of 171 examined sand lizards Lacerta agilis were PCR positive for Anaplasmataceae. The nucleotide sequences of the several selected PCR products showed 100% homology with Anaplasma spp. found in Ixodes ricinus collected in Tunisia and Morocco (AY672415 - AY672420). 1.2% of lizard collar scale samples were PCR positive for B. lusitaniae. In addition, 12 of 290 examined I. ricinus were PCR positive for B. burgdorferi s.l. and 82 were PCR positive for Anaplasmatacea. The number of ticks per lizard and the number of ticks PCR positive for both microorganisms per lizard were strongly correlated. Moreover, we found a significant correlation between numbers of ticks infected with Anaplasmataceae and with B. burgdorferi s.l. living on the same lizard. However, there was no significant correlation between detection of both bacteria in the same tick., Conclusions: To the best of our knowledge, this is the first report of Anaplasmataceae DNA and additionally the second report of B. burgdorferi s.l DNA detection in the sand lizard.

Background: Borrelia burgdorferi sensu lato (s.l.) are the causative agent for Lyme borreliosis (LB), the most common tick-borne disease in the northern hemisphere. Birds are considered important in the global dispersal of ticks and tick-borne pathogens through their migration. The present study is the first description of B. burgdorferi prevalence and genotypes in Ixodes ricinus ticks feeding on birds during spring and autumn migration in Norway., Methods: 6538 migratory birds were captured and examined for ticks at Lista Bird Observatory during the spring and the autumn migration in 2008. 822 immature I. ricinus ticks were collected from 215 infested birds. Ticks were investigated for infection with B. burgdorferi s.l. by real-time PCR amplification of the 16S rRNA gene, and B. burgdorferi s.l. were thereafter genotyped by melting curve analysis after real-time PCR amplification of the hbb gene, or by direct sequencing of the PCR amplicon generated from the rrs (16S)-rrl (23S) intergenetic spacer., Results: B. burgdorferi s.l. were detected in 4.4% of the ticks. The most prevalent B. burgdorferi genospecies identified were B. garinii (77.8%), followed by B.valaisiana (11.1%), B. afzelii (8.3%) and B. burgdorferi sensu stricto (2.8%)., Conclusion: Infection rate in ticks and genospecies composition were similar in spring and autumn migration, however, the prevalence of ticks on birds was higher during spring migration. The study supports the notion that birds are important in the dispersal of ticks, and that they may be partly responsible for the heterogeneous distribution of B. burgdorferi s.l. in Europe.

Background: Rickettsial diseases associated with the spotted fever group constitute a growing number of newly identified Rickettsia pathogens and their tick vectors in various parts of the world. At least 15 distinct tick species belonging to six genera have shown the presence of Rickettsia raoultii. Herein, we report the detection of R. raoultii in ticks from the Republic of Korea (ROK). Methods: Thirty-five ticks were collected from 29 patients with tick bites in Gwangju Metropolitan City, Jeollanam Province, ROK. The ticks were identified using molecular, morphological, and taxonomic characteristics. All samples were screened for presence of Rickettsia species using nested polymerase chain reactions of their outer membrane protein (ompA) and citrate synthase (gltA) genes. The amplified products were sequenced for subsequent phylogenetic analyses. Results: Sequencing data showed the DNA sequences of R. raoultii in three Haemaphysalis longicornis ticks. All three tick samples were 99.4–100% similar to previously reported partial sequences of ompA of R. raoultii strains CP019435 and MF002523, which formed a single clade with the reference strains. Conclusions: We provide the first description and molecular identification of R. raoultii detected in H. longicornis ticks in the ROK. This observation extends the geographical distribution of R. raoultii. Screening of human samples for this pathogen will provide information about the prevalence of rickettsial infections in this region. [ABSTRACT FROM AUTHOR]

Background: Lyme disease continues to expand in Canada and the USA and no single intervention is likely to curb the epidemic. Methods: We propose a platform to quantitatively assess the effectiveness of a subset of Ixodes scapularis tick management approaches. The platform allows us to assess the impact of different control treatments, conducted either individually (single interventions) or in combination (combined efforts), with varying timings and durations. Interventions include three low environmental toxicity measures in differing combinations, namely reductions in white-tailed deer (Odocoileus virginianus) populations, broadcast area-application of the entomopathogenic fungus Metarhizium anisopliae, and fipronil-based rodent-targeted bait boxes. To assess the impact of these control efforts, we calibrated a process-based mathematical model to data collected from residential properties in the town of Redding, southwestern Connecticut, where an integrated tick management program to reduce I.xodes scapularis nymphs was conducted from 2013 through 2016. We estimated parameters mechanistically for each of the three treatments, simulated multiple combinations and timings of interventions, and computed the resulting percent reduction of the nymphal peak and of the area under the phenology curve. Results: Simulation outputs suggest that the three-treatment combination and the bait boxes–deer reduction combination had the overall highest impacts on suppressing I. scapularis nymphs. All (single or combined) interventions were more efficacious when implemented for a higher number of years. When implemented for at least 4 years, most interventions (except the single application of the entomopathogenic fungus) were predicted to strongly reduce the nymphal peak compared with the no intervention scenario. Finally, we determined the optimal period to apply the entomopathogenic fungus in residential yards, depending on the number of applications. Conclusions: Computer simulation is a powerful tool to identify the optimal deployment of individual and combined tick management approaches, which can synergistically contribute to short-to-long-term, costeffective, and sustainable control of tick-borne diseases in integrated tick management (ITM) interventions. [ABSTRACT FROM AUTHOR]

Background: Tick-borne diseases are a growing public health threat in the United States. Despite the prevalence and rising burden of tick-borne diseases, there are major gaps in baseline knowledge and surveillance efforts for tick vectors, even among vector control districts and public health agencies. To address this issue, an online tick training course (OTTC) was developed through the Southeastern Center of Excellence in Vector-Borne Diseases (SECOEVBD) to provide a comprehensive knowledge base on ticks, tick-borne diseases, and their management. Methods: The OTTC consisted of training modules covering topics including tick biology, tick identification, tick-borne diseases, and public health, personal tick safety, and tick surveillance. The course was largely promoted to vector control specialists and public health employees throughout the Southeastern US. We collected assessment and survey data on participants to gauge learning outcomes, perceptions of the utility of knowledge gained, and barriers and facilitators to applying the knowledge in the field. Results: The OTTC was successful in increasing participants' baseline knowledge across all course subject areas, with the average score on assessment increasing from 62.6% (pre-course) to 86.7% (post-course). More than half of participants (63.6%) indicated that they would definitely use information from the course in their work. Barriers to using information identified in the delayed assessment included lack of opportunities to apply skills (18.5%) and the need for additional specialized training beyond what the OTTC currently offers (18.5%), while the main facilitator (70.4%) for applying knowledge was having opportunities at work, such as an existing tick surveillance program. Conclusions: Overall, this OTTC demonstrated capacity to improve knowledge in a necessary and underserved public health field, and more than half of participants use or plan to use the information in their work. The geographic reach of this online resource was much larger than simply for the Southeastern region for which it was designed, suggesting a much broader need for this resource. Understanding the utility and penetrance of training programs such as these is important for refining materials and assessing optimal targets for training. [ABSTRACT FROM AUTHOR]

Background: Lyme disease (LD) has become the most common vector borne illness in the Northern hemisphere. Prevention relies predominantly on fostering protective behaviors (e.g., avoiding tick areas, using protective clothing and repellent, and doing routine tick checks post-exposure). The objective of this study was to evaluate the effectiveness (in terms of knowledge, perceived severity and susceptibility, self-efficacy, response efficacy, intention, and behavior over time) and appreciation of a leaflet and a movie as tools for informing the public in the Netherlands about ticks and LD protective behaviors., Methods: Participants (1,677 at t1 and 361 extra at t2) were members of a representative Internet panel (adults aged 18 years and above). A four group randomized controlled design was used to test the effect of an information leaflet and a movie (two intervention groups), compared to a control group and a follow-up only control group. Data were collected over two periods: July 15-29, 2013 (t1) and at follow-up 4 weeks later, August 16-31, 2013 (t2)., Results: Post-intervention results show all respondents in all groups possess good general basic knowledge of ticks and LD. Respondents in both the leaflet and movie groups knew more than respondents in the control group, and had greater awareness of best practices after a tick bite. Intention to perform protective behavior in future was stronger among respondents in the intervention groups. While respondents generally appreciated both the movie and the leaflet, they found the movie ran too long. Follow-up revealed no lasting positive effects from either the leaflet or the movie., Conclusions: Our results suggest that both the movie and the leaflet are valued and effective intervention tools for improving knowledge about tick bites and strengthening self-efficacy and intentions to perform protective behavior against ticks and LD . Achieving lasting effects, however, calls for more action.

A molecular surveillance of tick-borne diseases was performed in Hulunbuir City, Inner Mongolia. A total of 149 ticks including three species (Ixodes persulcatus, Haemaphysalis concinna, and Dermacentor silvarum) were collected. As many as 11 tick-borne bacterial pathogens were identified in them. Some of them have high positive rates. For example, Candidatus Rickettsia tarasevichiae was detected with a high prevalence of 72.48%, while Candidatus Lariskella sp. was detected in 31.54% of ticks. For both Rickettsia raoultii and Anaplasma phagocytophilum, two distinct genotypes were identified based on their phylogenetic trees based on 16S rRNA, gltA, and groEL sequences. Remarkable genetic diversity was also observed for 16S and flaB genes of Borreliella garinii, an agent of Lyme disease. Rickettsia heilongjiangensis causing Far-Eastern spotted fever (2.68%, 4/149), Ehrlichia muris causing human ehrlichiosis (4.70%, 7/149), Borrelia miyamotoi causing relapsing fever (2.01%, 3/149), and Borreliella afzelii causing Lyme disease (2.01%, 3/149) were also detected. Additionally, a previously uncharacterized Anaplasma species closely related to Anaplasma ovis was identified. Herein we name it "Candidatus Anaplasma mongolica". Based on these results, we propose that Yakeshi City might be a potential hotspot of tick-borne diseases., (© 2023. The Author(s).)

Domestic dogs are susceptible to numerous vector-borne pathogens that are of significant importance for their health. In addition to being of veterinary importance, many of these pathogens are zoonotic and thus may pose a risk to human health. In the USA, owned dogs are commonly screened for exposure to or infection with several canine vector-borne pathogens. Although the screening data are widely available to show areas where infections are being diagnosed, testing of owned dogs is expected to underestimate the actual prevalence in dogs that have no access to veterinary care. The goal of this study was to measure the association between the widely available data from a perceived low-risk population with temporally and spatially collected data from shelter-housed dog populations. These data were then used to extrapolate the prevalence in dogs that generally lack veterinary care. The focus pathogens included Dirofilaria immitis, Ehrlichia spp., Anaplasma spp., and Borrelia burgdorferi. There was a linear association between the prevalence of selected vector-borne pathogens in shelter-housed and owned dog populations and, generally, the data suggested that prevalence of heartworm (D. immitis) infection and seroprevalence of Ehrlichia spp. and B. burgdorferi are higher in shelter-housed dogs, regardless of their location, compared with the owned population. The seroprevalence of Anaplasma spp. was predicted to be higher in areas that have very low to low seroprevalence, but unexpectedly, in areas of higher seroprevalence within the owned population, the seroprevalence was expected to be lower in the shelter-housed dog population. If shelters and veterinarians make decisions to not screen dogs based on the known seroprevalence of the owned group, they are likely underestimating the risk of exposure. This is especially true for heartworm. With this new estimate of the seroprevalence in shelter-housed dogs throughout the USA, shelters and veterinarians can make evidence-based informed decisions on whether testing and screening for these pathogens is appropriate for their local dog population. This work represents an important step in understanding the relationships in the seroprevalences of vector-borne pathogens between shelter-housed and owned dogs, and provides valuable data on the risk of vector-borne diseases in dogs., (© 2023. The Author(s).)

Background: Lyme borreliosis is the most common vector-borne disease in Europe and North America. The objective of this study is to estimate the incidence of tick bites and Lyme borreliosis, representative of our entire country, including erythema migrans, disseminated Lyme borreliosis and persisting symptoms attributed to Lyme borreliosis., Methods: A questionnaire on clinical diagnoses of Lyme borreliosis was sent to all GPs, company physicians, and medical specialists. To adjust for possible misclassification and telescoping bias, we sent additional questionnaires to categorize reported cases according to likelihood of the diagnosis and to exclude cases diagnosed outside the target period., Results: Adjusted annual incidence rate for disseminated Lyme borreliosis was 7.7 GP reports per 100,000 inhabitants, and for persisting symptoms attributed to Lyme borreliosis was 5.5 GP reports per 100,000 inhabitants, i.e. approximately 1,300 and 900 cases respectively. GP consultations for tick bites and erythema migrans diagnoses were 495 and 132 per 100,000 inhabitants, respectively, i.e. 82,000 and 22,000 cases in 2010., Conclusions: This is the first reported nationwide physician survey on the incidence of tick bites and the whole range of manifestations of Lyme borreliosis, including persisting symptoms attributed to Lyme borreliosis. This is crucial for complete assessment of the public health impact of Lyme borreliosis.

Background: Within-host microbial communities and interactions among microbes are increasingly recognized as important factors influencing host health and pathogen transmission. The microbial community associated with a host is indeed influenced by a complex network of direct and indirect interactions between the host and the lineages of microbes it harbors, but the mechanisms are rarely established. We investigated the within-host interactions among strains of Borrelia burgdorferi, the causative agent of Lyme disease, using experimental infections in mice. We used a fully crossed-design with three distinct strains, each group of hosts receiving two sequential inoculations. We used data from these experimental infections to assess the effect of coinfection on bacterial dissemination and fitness (by measuring the transmission of bacteria to xenodiagnostic ticks) as well as the effect of coinfection on host immune response compared to single infection., Results: The infection and transmission data strongly indicate a competitive interaction among B. burgdorferi strains within a host in which the order of appearance of the strain is the main determinant of the competitive outcome. This pattern is well described by the classic priority effect in the ecological literature. In all cases, the primary strain a mouse was infected with had an absolute fitness advantage primarily since it was transmitted an order of magnitude more than the secondary strain. The mechanism of exclusion of the secondary strain is an inhibition of the colonization of mouse tissues, even though 29% of mice showed some evidence of infection by secondary strain. Contrary to expectation, the strong and specific adaptive immune response evoked against the primary strain was not followed by production of immunoglobulins after the inoculation of the secondary strain, neither against strain-specific antigen nor against antigens common to all strains. Hence, the data do not support a major role of the immune response in the observed priority effect., Conclusion: The strong inhibitory priority effect is a dominant mechanism underlying competition for transmission between coinfecting B. burgdorferi strains, most likely through resource exploitation. The observed priority effect could shape bacterial diversity in nature, with consequences in epidemiology and evolution of the disease.

Background: Lyme disease (LD) is a vector-borne disease that is endemic in many temperate countries, including Switzerland, and is currently emerging in Canada. This study compares the importance of knowledge, exposure and risk perception for the adoption of individual preventive measures, within and between two different populations, one that has been living in a LD endemic region for several decades, the Neuchâtel canton in Switzerland, and another where the disease is currently emerging, the Montérégie region in the province of Québec, Canada., Methods: A web-based survey was carried out in both study regions (814 respondents) in 2012. Comparative analysis of the levels of adoption of individual preventive measures was performed and multivariable logistic regression analyses were used to test and compare how knowledge, exposure and risk perception were associated with the adoption of selected measures in both regions and globally., Results: In Montérégie, the proportion of reported adoption of five of the most commonly recommended preventive measures varied from 6% for 'applying acaricides on one's property' to 49% for 'wearing protective clothing', and in Neuchâtel, proportions ranged from 6% (acaricides) to 77% for 'checking for ticks (tick check)'. Differences were found within gender, age groups and exposure status in both regions. The perceived efficacy of a given measure was the strongest factor associated with the adoption of three specific preventive behaviors for both regions: tick check, protective clothing and tick repellent. Risk perception and a high level of knowledge about LD were also significantly associated with some of these specific behaviors, but varied by region., Conclusions: These results strongly suggest that social and contextual factors such as the epidemiological status of a region are important considerations to take into account when designing effective prevention campaigns for Lyme disease. It furthermore underlines the importance for public health authorities to better understand and monitor these factors in targeted populations in order to be able to implement preventive programs that are well adapted to a population and the epidemiological contexts therein.

Background: Borrelia miyamotoi is a newly described relapsing fever spirochete transmitted by ixodid tick species. Little is known about the prevalence of B. miyamotoi infections in humans and ticks in Inner Mongolia, China. Therefore, we investigated the prevalence of B. miyamotoi in Ixodes persulcatus ticks, and we aimed to isolateB. miyamotoi from I. persulcatus from four regions of Greater Khingan, Inner Mongolia, China. Methods: From May to June each year during the period 2016–2019, host-seeking adult I. persulcatus ticks were collected from vegetation. Genomic DNA was prepared from half of each tick body for PCR template, and the remaining half was used to cultivate B. miyamotoi in BSK-M medium. We employed quantitative real-time PCR (qPCR) to detect Borrelia DNA in the ticks and to calculate the prevalence of B. miyamotoi and infections with other borreliae. For characterization of the isolated B. miyamotoi, we performed draft genome sequencing and multilocus sequencing analysis (MLSA). Results: A total of 2656 adult I. persulcatus ticks were collected. The overall prevalence of relapsing fever (RF) borreliae in ticks was 5.0% (134/2656) and that of Lyme disease (LD) borreliae was 43.8% (1164/2656). Co-infection with RF and LD borreliae was observed in 63 ticks (2.4%). Ticks that were positive for RF borreliae by qPCR were subjected to glycerophosphodiester diester phosphodiesterase gene (glpQ) PCR amplification and sequencing, through which we identified the RF borrelia specimens as B. miyamotoi. Furthermore, the B. miyamotoi strain Hetao-1 was isolated from I. persulcatus, and a draft genome sequence was obtained from the isolate. Sequencing determined the strain Hetao-1 genome to be approximately 906.1 kbp in length (28.9% average GC content), and MLSA identified the strain as ST633, which has previously been reported in Japan and Mongolia. Conclusion: We detected B. miyamotoi from I. persulcatus ticks collected in Inner Mongolia, and successfully isolated a B. miyamotoi strain. To our knowledge, this is the first study to culture a B. miyamotoi isolate from China. The data on the prevalence of B. miyamotoi and other borreliae in I. persulcatus ticks will be fundamental for future epidemiological studies of B. miyamotoi disease in Inner Mongolia. [ABSTRACT FROM AUTHOR]

Background: The blacklegged tick, Ixodes scapularis, is the primary vector of the Lyme disease spirochete Borrelia burgdorferi in North America. Though the tick is found across the eastern United States, Lyme disease is endemic to the northeast and upper midwest and rare or absent in the southern portion of the vector's range. In an effort to better understand the tick microbiome from diverse geographic and climatic regions, we analysed the bacterial community of 115 I. scapularis adults collected from vegetation in Texas and Massachusetts, representing extreme ends of the vector's range, by massively parallel sequencing of the 16S V4 rRNA gene. In addition, 7 female I. scapularis collected from dogs in Texas were included in the study. Results: Male I. scapularis ticks had a more diverse bacterial microbiome in comparison to the female ticks. Rickettsia spp. dominated the microbiomes of field-collected female I. scapularis from both regions, as well as half of the males from Texas. In addition, the male and female ticks captured from Massachusetts contained high proportions of the pathogens Anaplasma and Borrelia, as well as the arthropod endosymbiont Wolbachia. None of these were found in libraries generated from ticks collected in Texas. Pseudomonas, Acinetobacter and Mycobacterium were significantly differently abundant (p < 0.05) between the male ticks from Massachusetts and Texas. Anaplasma and Borrelia were found in 15 and 63% of the 62 Massachusetts ticks, respectively, with a co-infection rate of 11%. Female ticks collected from Texas dogs were particularly diverse, and contained several genera including Rickettsia, Pseudomonas, Bradyrhizobium, Sediminibacterium, and Ralstonia. Conclusions: Our results indicate that the bacterial microbiomes of I. scapularis ticks vary by sex and geography, with significantly more diversity in male microbiomes compared to females. We found that sex plays a larger role than geography in shaping the composition/diversity of the I. scapularis microbiome, but that geography affects what additional taxa are represented (beyond Rickettsia) and whether pathogens are found. Furthermore, recent feeding may have a role in shaping the tick microbiome, as evident from a more complex bacterial community in female ticks from dogs compared to the wild-caught questing females. These findings may provide further insight into the differences in the ability of the ticks to acquire, maintain and transmit pathogens. Future studies on possible causes and consequences of these differences will shed additional light on tick microbiome biology and vector competence. [ABSTRACT FROM AUTHOR]

Background: Lyme disease is one of the most commonly reported infectious diseases in the United States (US), accounting for more than [Formula: see text] of all vector-borne diseases in North America., Objective: In this paper, self-reported tweets on Twitter were analyzed in order to predict potential Lyme disease cases and accurately assess incidence rates in the US., Methods: The study was done in three stages: (1) Approximately 1.3 million tweets were collected and pre-processed to extract the most relevant Lyme disease tweets with geolocations. A subset of tweets were semi-automatically labelled as relevant or irrelevant to Lyme disease using a set of precise keywords, and the remaining portion were manually labelled, yielding a curated labelled dataset of 77, 500 tweets. (2) This labelled data set was used to train, validate, and test various combinations of NLP word embedding methods and prominent ML classification models, such as TF-IDF and logistic regression, Word2vec and XGboost, and BERTweet, among others, to identify potential Lyme disease tweets. (3) Lastly, the presence of spatio-temporal patterns in the US over a 10-year period were studied., Results: Preliminary results showed that BERTweet outperformed all tested NLP classifiers for identifying Lyme disease tweets, achieving the highest classification accuracy and F1-score of [Formula: see text]. There was also a consistent pattern indicating that the West and Northeast regions of the US had a higher tweet rate over time., Conclusions: We focused on the less-studied problem of using Twitter data as a surveillance tool for Lyme disease in the US. Several crucial findings have emerged from the study. First, there is a fairly strong correlation between classified tweet counts and Lyme disease counts, with both following similar trends. Second, in 2015 and early 2016, the social media network like Twitter was essential in raising popular awareness of Lyme disease. Third, counties with a high incidence rate were not necessarily related with a high tweet rate, and vice versa. Fourth, BERTweet can be used as a reliable NLP classifier for detecting relevant Lyme disease tweets., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Background: Lyme borreliosis and other tick-borne diseases emerge from increased interactions between humans, other animals, and infected ticks. The risk of acquiring a tick-borne infection varies across space and time, so knowledge of the occurrence and prevalence of pathogens in ticks can facilitate disease diagnosis in a specific area and the implementation of mitigation measures and awareness campaigns. Here we identify the occurrence and prevalence of several pathogens in Ixodes ricinus ticks in Wester Ross, Northwest Scotland, a region of high tourism and tick exposure, yet data-poor in terms of tick-borne pathogens. Methods: Questing I. ricinus nymphs (n = 2828) were collected from 26 sites in 2018 and 2019 and tested for the presence of tick-borne pathogens using PCR-based methods. Prevalence was compared with other regions of Scotland, England, Wales, and the Netherlands. Results: Anaplasma phagocytophilum (4.7% prevalence), Borrelia burgdorferi sensu lato (s.l.) (2.2%), Babesia from clade X (0.2%), Rickettsia helvetica (0.04%), and Spiroplasma ixodetis (0.4%) were detected, but no Neoehrlichia mikurensis, Borrelia miyamotoi, or Babesia microti. Typing of A. phagocytophilum using a fragment of the GroEL gene identified the presence of both ecotype I and ecotype II. Genospecies identification of Borrelia burgdorferi s.l. revealed B. afzelii (53% of infected nymphs), B. garinii (9%), B. burgdorferi sensu stricto (7%), and B. valaisiana (31%). We found similar prevalence of A. phagocytophilum in Wester Ross as in the Netherlands, but higher than in other parts of Great Britain. We found lower B. burgdorferi s.l. prevalence than in England or the Netherlands, and similar to some other Scottish studies. We found higher prevalence of B. valaisiana and lower prevalence of B. garinii than in other Scottish studies. We found S. ixodetis at much lower prevalence than in the Netherlands, and R. helvetica at much lower prevalence than in England and the Netherlands. Conclusions: As far as we know, this is the first description of S. ixodetis in Great Britain. The results are relevant for disease surveillance and management for public and veterinary health. The findings can also aid in designing targeted public health campaigns and in raising awareness among outdoor recreationists and professionals. [ABSTRACT FROM AUTHOR]