Bridging the gap: Insights in the immunopathology of Lyme borreliosis.

Lyme borreliosis (LB), caused by Borrelia burgdorferi sensu lato (Bbsl) genospecies transmitted by Ixodes spp. ticks, is a significant public health concern in the Northern Hemisphere. This review highlights the complex interplay between Bbsl infection and host-immune responses, impacting clinical manifestations and long-term immunity. Early localized disease is characterized by erythema migrans (EM), driven by T-helper 1 (Th1) responses and proinflammatory cytokines. Dissemination to the heart and CNS can lead to Lyme carditis and neuroborreliosis respectively, orchestrated by immune cell infiltration and chemokine dysregulation. More chronic manifestations, including acrodermatitis chronica atrophicans and Lyme arthritis, involve prolonged inflammation as well as the development of autoimmunity. In addition, dysregulated immune responses impair long-term immunity, with compromised B-cell memory and antibody responses. Experimental models and clinical studies underscore the role of Th1/Th2 balance, B-cell dysfunction, and autoimmunity in LB pathogenesis. Moreover, LB-associated autoimmunity parallels mechanisms observed in other infectious and autoimmune diseases. Understanding immune dysregulation in LB provides insights into disease heterogeneity and could provide new strategies for diagnosis and treatment.

Borrelia burgdorferi infections in children and adolescents in Switzerland - a seroprevalence study 2023/2024 (BOBUINCA).

BACKGROUND: Lyme borreliosis is one of the most prevalent tick-borne diseases in Europe. Studies on seroprevalence of Borrelia burgdorferi IgG antibodies in children are rare. The aim of this study was to determine the seroprevalence of B. burgdorferi IgG antibodies in children and adolescents residing in North-Western Switzerland and neighbouring countries. METHODS: Prospective cross-sectional observational single-centre study using left-over plasma of asymptomatic paediatric patients. Included were children aged 1-17 years living in North-Western Switzerland and bordering areas of France and Germany. Excluded were children with symptoms of Lyme borreliosis or a chronic disease possibly affecting plasma antibodies (immunodeficiency syndrome, systemic lupus erythematosus) or with such medication (e.g., intravenous immunoglobuline treatment, allogenic stem cell transplantation, immunosuppressive treatment) as well as refugees seeking asylum. IgG antibodies against B. burgdorferi were measured by ELISA and positive or borderline results by line blot. Positivity was defined as scenario 1: ELISA positive/line blot positive or borderline OR ELISA borderline/line blot positive. Scenario 2: ELISA positive or borderline/line blot positive. A multivariable logistic regression model for seropositivity was applied. RESULTS: 962 children were included (mean age 9.63 years, standard deviation 5.01, 54.5% males). Seroprevalence for scenario 1 was 13.3% (95% CI: 11.2-15.6) and for scenario 2 11.2% (95% CI: 9.3-13.4). Seroprevalence (scenario 1) was comparable for age groups, sex and rural versus urban residence. CONCLUSION: This study shows an increased seroprevalence for B. burgdorferi in the paediatric age compared to previous childhood studies. We also found an increased risk for B. burgdorferi infection at young age.

Lyme borreliosis and medical wandering: what do patients think about multidisciplinary management? A qualitative study in the context of scientific and social controversy.

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.

Genome-wide analyses in Lyme borreliosis: identification of a genetic variant associated with disease susceptibility and its immunological implications.

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).

Spatial multi-criteria decision analysis for the selection of sentinel regions in tick-borne disease surveillance.

BACKGROUND: The implementation of cost-effective surveillance systems is essential for tracking the emerging risk of tick-borne diseases. In Canada, where Lyme disease is a growing public health concern, a national sentinel surveillance network was designed to follow the epidemiological portrait of this tick-borne disease across the country. The surveillance network consists of sentinel regions, with active drag sampling carried out annually in all regions to assess the density of Ixodes spp. ticks and prevalence of various tick-borne pathogens in the tick population. The aim of the present study was to prioritize sentinel regions by integrating different spatial criteria relevant to the surveillance goals. METHODS: We used spatially-explicit multi-criteria decision analyses (MCDA) to map priority areas for surveillance across Canada, and to evaluate different scenarios using sensitivity analyses. Results were shared with stakeholders to support their decision making for the selection of priority areas to survey during active surveillance activities. RESULTS: Weights attributed to criteria by decision-makers were overall consistent. Sensitivity analyses showed that the population criterion had the most impact on rankings. Thirty-seven sentinel regions were identified across Canada using this systematic and transparent approach. CONCLUSION: This novel application of spatial MCDA to surveillance network design favors inclusivity of nationwide partners. We propose that such an approach can support the standardized planning of spatial design of sentinel surveillance not only for vector-borne disease BDs, but more broadly for infectious disease surveillance where spatial design is an important component.

Not bitten by Ixodes ticks or bitten without symptoms, why still to worry?

OBJECTIVES: The purpose of the current study was to analyse the risks of Lyme borreliosis (LB) among 1,070 forestry workers, the influence of responsible behaviour (use of repellents, skin self-inspection) on Borrelia screening result status, and the occurrence of immediate and mid-term symptoms after tick bites and LB positive serological screening test. METHODS: The questionnaire was conducted as well as blood tests for LB disease by one-stage serological screening procedure using ELISA for specific B. burgdorferi IgM and IgG antibodies (EuroImmun AG company, Germany). RESULTS: While 39.6% of foresters were LB positive among bitten foresters, as many as 27.0% were LB positive among those, who did not recall any tick attacks at all. Individuals with known history of tick bites had significantly higher odds (1.770×) of being LB positive (p < 0.05), while the use of repellents or skin self-inspection after visiting woods had no influence on LB results. The odds of skin discolouration after tick bites was significantly lower (0.682×) in case of LB positive test compared to LB negative test (p < 0.05), which can be explained by the fact that foresters could be unaware about erythema migrans appearance and timing, considering tick bite and developed later rash as completely separate events. Moreover, 69.1% of the bitten foresters with LB positive result developed no secondary symptoms (excluding those related to the skin), and the most frequent clinical symptoms were arthralgia (24.9%), followed by myalgia (7.6%), headache (5.7%), and damage to facial nerve (2.7%), which are non-specific and can be present in other illnesses. CONCLUSION: Therefore, the recommendations proposed would be the regular laboratory testing for LB of sensitive and at-risk population, who visits endemic woody areas, irrespective of all other factors involved.

Lyme Borreliosis, a public health concern in India: Findings of Borrelia burgdorferi serosurvey from two states.

Background: Lyme borreliosis is a public health concern in India. The prevalence of the disease is still undetermined with major entomological and epidemiological gaps. The present study was conducted to determine the seropositivity of Borrelia burgdorferi in Sikkim and Arunachal Pradesh, India. Methods: A cross-sectional serosurvey was conducted in Sikkim and Arunachal Pradesh. Data collection tools were developed and standardized for the collection of clinico-socio-demographic data. Sample size for each site was calculated using the formula for the estimation of a single proportion. Qualitative detection of IgG antibodies in serum samples was done using NovaLisa™ Lyme Borrelia IgG ELISA kit. Results: A total of 793 participants were enrolled, 484 (61%) from Arunachal Pradesh and 309 (39%) from Sikkim. Out of 793 participants, 21 (2.7%), 22 (2.8%), 6 (0.8%), 29 (3.7%), 44 (5.5%), and 16 (2.1%) gave history of tick bite, rash, erythema migrans, migratory muscle pain, migratory joint pain, and numbness, respectively, in the past one year. The adjusted seroprevalence (for sensitivity and specificity of kit) for the study is 3.7 (2.4-5.2). No signs or symptoms were found to be associated with IgG ELISA positivity. The state-wise distribution of seropositivity for Arunachal Pradesh and Sikkim was 4.1 (95% CI: 2.5-6.3) and 2.3 (95% CI: 0.9-4.6), respectively. Conclusion: This study establishes the state of Sikkim as a new endemic area in India of Lyme disease besides its already reported endemicity in Arunachal Pradesh. No association was conclusively established between symptoms of Lyme and IgG seropositivity emphasizing the need for detailed history taking and clinical suspicion in endemic areas.

Erythema Migrans Caused by Borrelia spielmanii, France.

We describe a rare case of early Lyme borreliosis in France caused by Borrelia spielmanii, which manifested as a large erythema chronicum migrans rash. The patient completely recovered after a 15-day course of amoxicillin. Absence of pathognomonic signs prevented distinguishing B. spielmanii from other etiologies as cause in this case-patient.

The emergence and shift in seasonality of Lyme borreliosis in Northern Europe.

Climate change has had a major impact on seasonal weather patterns, resulting in marked phenological changes in a wide range of taxa. However, empirical studies of how changes in seasonality impact the emergence and seasonal dynamics of vector-borne diseases have been limited. Lyme borreliosis, a bacterial infection spread by hard-bodied ticks, is the most common vector-borne disease in the northern hemisphere and has been rapidly increasing in both incidence and geographical distribution in many regions of Europe and North America. By analysis of long-term surveillance data (1995-2019) from across Norway (latitude 57°58'-71°08' N), we demonstrate a marked change in the within-year timing of Lyme borreliosis cases accompanying an increase in the annual number of cases. The seasonal peak in cases is now six weeks earlier than 25 years ago, exceeding seasonal shifts in plant phenology and previous model predictions. The seasonal shift occurred predominantly in the first 10 years of the study period. The concurrent upsurgence in case number and shift in case timing indicate a major change in the Lyme borreliosis disease system over recent decades. This study highlights the potential for climate change to shape the seasonal dynamics of vector-borne disease systems.

Out of Asia? Expansion of Eurasian Lyme borreliosis causing genospecies display unique evolutionary trajectories.

Vector-borne pathogens exist in obligate transmission cycles between vector and reservoir host species. Host and vector shifts can lead to geographic expansion of infectious agents and the emergence of new diseases in susceptible individuals. Three bacterial genospecies (Borrelia afzelii, Borrelia bavariensis, and Borrelia garinii) predominantly utilize two distinct tick species as vectors in Asia (Ixodes persulcatus) and Europe (Ixodes ricinus). Through these vectors, the bacteria can infect various vertebrate groups (e.g., rodents, birds) including humans where they cause Lyme borreliosis, the most common vector-borne disease in the Northern hemisphere. Yet, how and in which order the three Borrelia genospecies colonized each continent remains unclear including the evolutionary consequences of this geographic expansion. Here, by reconstructing the evolutionary history of 142 Eurasian isolates, we found evidence that the ancestors of each of the three genospecies probably have an Asian origin. Even so, each genospecies studied displayed a unique substructuring and evolutionary response to the colonization of Europe. The pattern of allele sharing between continents is consistent with the dispersal rate of the respective vertebrate hosts, supporting the concept that adaptation of Borrelia genospecies to the host is important for pathogen dispersal. Our results highlight that Eurasian Lyme borreliosis agents are all capable of geographic expansion with host association influencing their dispersal; further displaying the importance of host and vector association to the geographic expansion of vector-borne pathogens and potentially conditioning their capacity as emergent pathogens.

Acceptance of diagnosis and management satisfaction of patients with "suspected Lyme borreliosis" after 12 months in a multidisciplinary reference center: a prospective cohort study.

INTRODUCTION: Because patients with a "suspicion of Lyme borreliosis (LB)" may experience medical wandering and difficult care paths, often due to misinformation, multidisciplinary care centers were started all over Europe a few years ago. The aim of our study was to prospectively identify the factors associated with the acceptance of diagnosis and management satisfaction of patients, and to assess the concordance of the medical health assessment between physicians and patients 12 months after their management at our multidisciplinary center. METHODS: We included all adults who were admitted to the Tick-Borne Diseases Reference Center of Paris and the Northern Region (TBD-RC) (2017-2020). A telephone satisfaction survey was conducted 12 months after their first consultation. It consisted of 5 domains and 13 items rated between 0 (lowest) and 10 (highest grade): (1)Reception; (2)Care and quality of management; (3)Information/explanations given to the patients; (4)Current medical condition and acceptance of the final diagnosis; (5)Overall appreciation. Factors associated with diagnosis acceptance and management satisfaction at 12 months were identified using logistic regression models. The concordance of the health status as assessed by doctors and patients was calculated using a Cohen's kappa test. RESULTS: Of the 569 patients who consulted, 349 (61.3%) answered the questionnaire. Overall appreciation had a median rating of 9 [8;10] and 280/349 (80.2%) accepted their diagnoses. Patients who were "very satisfied" with their care paths at TBD-RC (OR = 4.64;CI95%[1.52-14.16]) had higher odds of diagnosis acceptance. Well-delivered information was strongly associated with better satisfaction with the management (OR = 23.39;CI95%[3.52-155.54]). The concordance between patients and physicians to assess their health status 12 months after their management at TBD-RC was almost perfect in the groups of those with confirmed and possible LB (κ = 0.99), and moderate in the group with other diagnoses (κ = 0.43). CONCLUSION: Patients seemed to approve of this multidisciplinary care organization for suspected LB. It helped them to accept their final diagnoses and enabled a high level of satisfaction with the information given by the doctors, confirming the importance of shared medical decisions, which may help to reduce health misinformation. This type of structure may be useful for any disease with a complex and controversial diagnosis.

Mapping and monitoring tick (Acari, Ixodida) distribution, seasonality, and host associations in the United Kingdom between 2017 and 2020.

Tick-borne disease risk is intrinsically linked to the distribution of tick vector species. To assess risk and anticipate disease emergence, an understanding of tick distribution, host associations, and seasonality is needed. This can be achieved, to some extent, using passive surveillance supported by engagement with the public, animal health, and public health experts. The Tick Surveillance Scheme (TSS) collects data and maps tick distribution across the United Kingdom (UK). Between 2017 and 2020, 3720 tick records were received and 39 tick species were detected. Most records were acquired in the UK, with a subset associated with recent overseas travel. The dominant UK acquired species was Ixodes ricinus (Ixodida: Ixodidae, Linnaeus), the main vector of Lyme borreliosis. Records peaked during May and June, highlighting a key risk period for tick bites. Other key UK species were detected, including Dermacentor reticulatus (Ixodida: Ixodidae, Fabricius) and Haemaphysalis punctata (Ixodida: Ixodidae, Canestrini & Fanzago) as well as several rarer species that may present novel tick-borne disease risk to humans and other animals. Updated tick distribution maps highlight areas in the UK where tick exposure has occurred. There is evidence of increasing human tick exposure over time, including during the COVID-19 pandemic, but seasonal patterns remain unchanged.

Can protection motivation theory predict protective behavior against ticks?

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.

Spatial and seasonal determinants of Lyme borreliosis incidence in France, 2016 to 2021.

BackgroundLyme borreliosis (LB) is the most widespread hard tick-borne zoonosis in the northern hemisphere. Existing studies in Europe have focused mainly on acarological risk assessment, with few investigations exploring human LB occurrence.AimWe explored the determinants of spatial and seasonal LB variations in France from 2016 to 2021 by integrating environmental, animal, meteorological and anthropogenic factors, and then mapped seasonal LB risk predictions.MethodsWe fitted 2016-19 LB national surveillance data to a two-part spatio-temporal statistical model. Spatial and temporal random effects were specified using a Besag-York-Mollie model and a seasonal model, respectively. Coefficients were estimated in a Bayesian framework using integrated nested Laplace approximation. Data from 2020-21 were used for model validation.ResultsA high vegetation index (≥ 0.6) was positively associated with seasonal LB presence, while the index of deer presence (> 60%), mild soil temperature (15-22 °C), moderate air saturation deficit (1.5-5 mmHg) and higher tick bite frequency were associated with increased incidence. Prediction maps show a higher risk of LB in spring and summer (April-September), with higher incidence in parts of eastern, midwestern and south-western France.ConclusionWe present a national level spatial assessment of seasonal LB occurrence in Europe, disentangling factors associated with the presence and increased incidence of LB. Our findings yield quantitative evidence for national public health agencies to plan targeted prevention campaigns to reduce LB burden, enhance surveillance and identify further data needs. This approach can be tested in other LB endemic areas.

Seroprevalence, seroconversion and seroreversion of Borrelia burgdorferi-specific IgG antibodies in two population-based studies in children and adolescents, Germany, 2003 to 2006 and 2014 to 2017.

BackgroundLyme borreliosis (LB), caused by Borrelia burgdorferi (Bb), is the most common tick-borne infection in Germany. Antibodies against Bb are prevalent in the general population but information on temporal changes of prevalence and estimates of seroconversion (seroincidence) and seroreversion are lacking, especially for children and adolescents.AimWe aimed at assessing antibodies against Bb and factors associated with seropositivity in children and adolescents in Germany.MethodsWe estimated seroprevalence via two consecutive cross-sectional surveys (2003-2006 and 2014-2017). Based on a longitudinal survey component, we estimated annual seroconversion/seroreversion rates.ResultsSeroprevalence was 4.4% (95% confidence interval (CI): 3.9-4.9%) from 2003 to 2006 and 4.1% (95% CI: 3.2-5.1%) from 2014 to 2017. Seroprevalence increased with age, was higher in male children, the south-eastern regions of Germany and among those with a high socioeconomic status. The annual seroconversion rate was 0.3% and the annual seroreversion rate 3.9%. Males were more likely to seroconvert compared with females. Low antibody levels were the main predictor of seroreversion.ConclusionWe did not detect a change in seroprevalence in children and adolescents in Germany over a period of 11 years. Potential long-term changes, for example due to climatic changes, need to be assessed in consecutive serosurveys. Seroconversion was more likely among children and adolescents than among adults, representing a target group for preventive measures. Seroreversion rates are over twice as high in children and adolescents compared with previous studies among adults. Thus, seroprevalence estimates and seroconversion rates in children are likely underestimated.

Seroprevalence for Borrelia burgdorferi sensu lato and tick-borne encephalitis virus antibodies and associated risk factors among forestry workers in northern France, 2019 to 2020.

BackgroundLyme borreliosis (LB) is the most common tick-borne disease (TBD) in France. Forestry workers are at high risk of TBD because of frequent exposure to tick bites.AimWe aimed to estimate the seroprevalence of Borrelia burgdorferi sensu lato and tick-borne encephalitis virus (TBEV) antibodies among forestry workers in northern France. We compared seroprevalence by geographical area and assessed factors associated with seropositivity.MethodsBetween 2019 and 2020, we conducted a randomised cross-sectional seroprevalence survey. Borrelia burgdorferi sl seropositivity was defined as positive ELISA and positive or equivocal result in western blot. Seropositivity for TBEV was defined as positive result from two ELISA tests, confirmed by serum neutralisation. We calculated weighted seroprevalence and adjusted prevalence ratios to determine association between potential risk factors and seropositivity.ResultsA total of 1,778 forestry workers participated. Seroprevalence for B. burgdorferi sl was 15.5% (95% confidence interval (CI): 13.9-17.3), 3.5 times higher in the eastern regions than in the western and increased with seniority and with weekly time in a forest environment. Seroprevalence was 2.5 times higher in forestry workers reporting a tick bite during past years and reporting usually not removing ticks rapidly. Seroprevalence for TBEV was 0.14% (95% CI: 0.05-0.42).ConclusionWe assessed for the first time seroprevalence of B. burgdorferi sl and TBEV antibodies among forestry workers in northern France. These results will be used, together with data on LB and tick-borne encephalitis (TBE) incidence and on exposure to tick-bites, to target prevention programmes.

Estimated number of symptomatic Lyme borreliosis cases in Germany in 2021 after adjusting for under-ascertainment.

BACKGROUND: Although nine of 16 federal states in Germany conduct public health surveillance for Lyme borreliosis (LB), the extent of under-ascertainment is unknown. OBJECTIVE: As a model for European countries that conduct LB surveillance, we sought to estimate the population-based incidence of symptomatic LB after adjusting for under-ascertainment. METHODS: Estimating seroprevalence-derived under-ascertainment relies on data from seroprevalence studies, public health surveillance, and published literature. The number of symptomatic LB cases in states that conduct LB surveillance was estimated from studies reporting the seroprevalence of antibodies against Borrelia burgdorferi sensu lato, the proportion of LB cases that are asymptomatic, and the duration of antibody detection. The number of estimated incident symptomatic LB cases was compared with the number of surveillance-reported LB cases to derive under-ascertainment multipliers. The multipliers were applied to the number of 2021 surveillance-reported LB cases to estimate the population-based incidence of symptomatic LB in Germany. RESULTS: Adjusting for seroprevalence-based under-ascertainment multipliers, the estimated number of symptomatic LB cases in states that conducted surveillance was 129,870 (408 per 100,000 population) in 2021. As there were 11,051 surveillance-reported cases in 2021 in these states, these data indicate there were 12 symptomatic LB cases for every surveillance-reported LB case. CONCLUSIONS: We demonstrate that symptomatic LB is underdetected in Germany and that this seroprevalence-based approach can be applied elsewhere in Europe where requisite data are available. Nationwide expansion of LB surveillance would further elucidate the true LB disease burden in Germany and could support targeted disease prevention efforts to address the high LB disease burden.

Lyme disease in Poland in 2021.

Introduction: Lyme disease, a zoonosis transmitted by vector (by ticks), may manifest itself in several different forms, such as: erythema migrans, osteoarticular or neuroborreliosis. Infection occurs when an infected common tick (Ixodes ricinus) feeds. Lyme disease is seasonal due to the cycle of tick activity throughout the year. Aim of the study: The aim of the study was to assess the epidemiological situation of Lyme disease in Poland in 2021 compared to the situation in previous years. Material and methods: To assess the epidemiological situation of Lyme disease in Poland, data sent to NIPH NIH - NRI by the Voivodeship Sanitary-Epidemiological Stations and published in the annual bulletin: "Infectious diseases and poisonings in Poland in 2021" were used. Results: In 2021, 12,500 cases of Lyme disease and 411 hospitalizations were registered, which means a decrease in the number of cases by 3.4% and a decrease in hospitalizations by 10.5%. The number of cases was similar to 2020, and Lyme disease cases did not return to the pre-COVID-19 pandemic level (approx. 20,000 cases per year). The quarterly distribution of cases remained unchanged, with cases occurring most frequently in Q3 and least frequently in Q1. Summary and conclusions: The impact of the COVID-19 pandemic on the number of reported Lyme disease cases was still noticeable, the number of recorded cases was lower than in the first pandemic year. The distribution of cases in quarters retained the seasonality characteristic of Lyme disease.

IMPACT OF CLINICAL CHARACTERISTICS OF LYME BORRELIOSIS ON PATIENTS' LIFE QUALITY.

OBJECTIVE: The aim: To study the impact of clinical characteristics of the disease on the life quality of patients with Lyme borreliosis. PATIENTS AND METHODS: Materials and methods: Forty-eight (33 women and 15 men) patients with Lyme borreliosis aged 23-77 years and 48 individuals who did not have any somatic diseases that would impact the quality of life (experimental group) were examined. The MOS 36-item Short Form Health Survey (SF-36) was used to study the quality of life. Cognitive function was assessed using the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). RESULTS: Results: According to the SF-36 questionnaire, patients with Lyme borreliosis had a significant decrease in scores for all indicators of physical health (р < 0.001), as well as impaired social (р < 0.001) and emotional (p = 0.027) functioning compared with healthy individuals. The deterioration of the quality of life indicators essentially depends on the clinical characteristics of the disease, namely its duration, the presence of Lyme arthritis, neuroborreliosis, cognitive disorders, multiple organ involvement, disease stage. CONCLUSION: Conclusions: Lyme borreliosis and its certain clinical characteristics have a significant impact on the life quality of patients.

Approach to prediction and receiver operating characteristic analysis of a regression model for assessing the severity of the course Lyme borreliosis in children.

Introduction: Lyme borreliosis (LB) is a multisystemic zoonotic disease transmitted by the bite of infected tick vectors.The aim of the study is to develop a mathematical model for predicting the risk of severity of Lyme disease by the risk factor of the disseminated form of LB in children who have had a tick attack. To test the effectiveness of the formula for predicting the development of the disseminated stage of LB, we built a receiver operating characteristic (ROC) curve and determined the specificity and sensitivity of our model. The results of the examination of 122 patients with the confirmed local and disseminated stages of LB were taken as a basis. Material and methods: To build a prognostic model for prediction of the risk of the developing of the stage in LB predicting the risk of severity of course in Lyme borreliosis (PRSCLB), 122 children (aged 13 ±3 years) with LB were examined using multivariate regression analysis, including 52 boys and 70 girls. Groups of patients: 79 children with erythema migrans, 16 with Lyme arthritis, and 27 with nervous system involvement by LB. The quality of the prognostic model was checked by the Nagelkerke R Square (Nagelkerke R2) and the acceptability of this model was assessed using ROC analysis. Results: The method of multivariate regression analysis for predicting severe course and organ and system damage in LB in children, taking into account the factors and variants of the disease itself, makes it possible to develop a mathematical model for predicting the relative response factors (RRF) of severe forms of Lyme disease and will improve the effectiveness of treatment. This will create all the prerequisites for high-quality preventive measures and reduce the relative response factors rate.The initial data for predicting the severity of LB were 28 factors. According to the results of regression analysis, 24 factors were included in the model for predicting the severity of LB. Conclusions: The results of the study showed that the multifactorial model predicts the severity and organ and system damage in LB in children with an accuracy of 95%. The ROC curve, which was built on the basis of the results, has an area under the curve of 0.94, which indicates the high efficiency of the model.