Current surveillance frameworks often fail to capture urban transmission of Lyme Borreliosis. The aim of this paper was not to privilege specific study designs, but to map the types of evidence currently informing risk assessment. The predominance of ecological proxies reflects how exposure is operationalized in the existing literature rather than a limitation of the paper itself. A scoping review was conducted in accordance with PRISMA-ScR guidelines. Peer-reviewed studies published between 2020 and 2025 were identified. Marked spatial heterogeneity was demonstrated.
Keywords
Borrelia burgdorferi Group. Europe. Lyme Disease. Urban Health
Introduction
Urban Lyme Borreliosis (LB) in Europe is not an emerging anomaly, but a persistent public health reality (Table 1, Table 2). Rather than providing a comprehensive epidemiological review, this article applies a structured evidence synthesis to identify monitoring-relevant blind spots in urban LB across the continent. The paper explicitly focuses on surveillance performance rather than ecological risk alone. This synthesis is intended to inform surveillance system design rather than to quantify absolute risk.
Table 1. Prevalence of Borrelia burgdorferi sensu lato in ticks collected from urban and peri-urban environments in selected European countries.
| Authors, Year, [Ref.*] | Country | Setting | Study objects | Key outcome |
| Robert et al.* 2025 [7] | Belgium | 185 urban, suburban, rural private gardens across Flanders | 1162 ticks (n*=1162) | Ticks found in all settings, 44.3% of gardens: 60.2% of rural gardens, 28.9% in suburban gardens, 50.0% of urban gardens. Bbsl* found in 19.6% of ticks. |
| Hoxha et al. 2025 [8] | Bosnia and Herzegovina | Urban, peri-urban, rural sites | 556 Ixodes ticks (n=556) | Ticks found in all sites; Bbsl detected in ∼18% of ticks |
| Balážová et al. 2024 [9] | Czech Republic | Urban areas (142 towns) | 12955 ticks (n=12955) | Bbsl detected in all sampled places with estimated prevalence 27.1% |
| Hansford et al. 2023 [10] | England | 18 urban, peri-urban, rural woodlands in and around the cities of Bath and Southampton | 1800 nymphs (n=1800) (100 from each of the woodlands) | I. ricinus found in all sampled places. Nymph density was similar across environments. The prevalence of Borrelia-infected nymphs was comparable. |
| Vikentjeva et al. 2024 [3] | Estonia | 14 urban areas of Tallinn | I. ricinus ticks | Ticks found at ∼71.4% places; Bbsl detected in 17.4% of the ticks |
| Sormunen et al. 2025 [11] | Finland | Urban and peri-urban (pets as sentinels) | 3697 I. ricinus (n=3697) and 2355 I. persulcatus* ticks (n=2355) | Borrelia spp. detected in 26.2% of adult ticks collected from pets |
| Mathews-Martin et al. 2020 [12] | France | 2 urban and 1 peri-urban parks | 506 I. ricinus ticks (n=506) | 7 ticks collected from 2 urban parks and 499 ticks from 1 peri-urban park. |
| Romiti et al. 2025 [13] | Italy | Urban (Rome) | 93 collected ticks (n=93) | No Bbsl detected in ticks, despite the presence of competent tick species. |
| Ciebiera et al. 2024 [14] | Poland | Urban green areas of the middle-sized city Zielona Góra | 115 I. ricinus ticks (n=115) | Borrelia spp. detected in 85.7% of I. ricinus ticks collected from ∼40.3% places |
Bbsl – Borrelia burgdorferi sensu lato; Borrelia spp. – Borrelia species; et al. – et alia (and others); I. persulcatus – Ixodes persulcatus; I. ricinus – Ixodes ricinus; n – number of examined ticks; Ref. – reference number (listed in References section).
Table 2. Surveillance-relevant risk signaling patterns of Lyme Borreliosis in selected European studies.
| Authors, Year, [Ref.*] | Urban risk interpretation |
| Robert et al.* 2025 [7] | Comparable risk |
| Hoxha et al. 2025 [8] | Comparable risk |
| Balážová et al. 2024 [9] | Sustained urban transmission |
| Hansford et al. 2023 [10] | Comparable risk |
| Vikentjeva et al. 2024 [3] | Sustained urban transmission |
| Sormunen et al. 2025 [11] | Potential urban exposure |
| Mathews-Martin et al. 2020 [12] | Reduced urban risk |
| Romiti et al. 2025 [13] | Reduced urban risk |
| Ciebiera et al. 2024 [14] | Elevated urban risk |
et al. – et alia (and others); Ref. – reference number (listed in References section).
The occurrence of LB varies widely across the continent, both between countries and within regions [1]. The highest regional seropositivity of antibodies against Bbsl is presented in Central Europe [2]. The expansion of urban green spaces may inadvertently increase human contact with ticks. Urban-adapted wildlife species and domestic animals create novel human-animal-vector interfaces [3,4], consistent with a One Health framework [5]. These ecological and social dynamics contribute to heterogeneity in LB risk along the urban-rural gradient.
In contrast to previous systematic reviews focusing on incidence and epidemiological burden, the primary novelty of this review lies in its surveillance-focused synthesis rather than epidemiological quantification. Urban LB should be considered a surveillance priority rather than an ecological curiosity. This paper demonstrates that urban-rural dichotomy is epidemiologically out-of-date for LB risk assessment in Europe.
Methods
Study design and scope
A scoping review was conducted to map the risk of LB in urban, peri-urban, and rural environments across Europe. This scoping review was conducted and reported in accordance with the PRISMA extension for Scoping Reviews (PRISMA-ScR) guidelines [6]. The selection process is summarized in a PRISMA-ScR flow diagram (Figure 1).
Figure 1. Flowchart of selection process for the scoping review of Lyme Borreliosis in Europe, 1 January 2020–31 December 2025.
Records were identified through database searches and other sources, screened according to predefined eligibility criteria, and assessed for inclusion. A total of 21 studies met the inclusion criteria and were included in the study.
Data sources and search strategy
PubMed/MEDLINE, Web of Science, and Scopus were searched for peer-reviewed studies. To ensure that the findings reflect the most current data, this paper was restricted to studies published between 2020 and 2025. This period captures recent developments in urbanization, climate change, and tick ecology, which are known to influence the distribution of Ixodes ticks and the risk of LB. Search terms included “Lyme borreliosis”, “Borrelia burgdorferi”, “Ixodes ricinus”, “urbanization”, and “Europe”.
Eligibility criteria
Included studies:
- Conducted in European countries;
- Focused on LB, Borrelia burgdorferi sensu lato (Bbsl) spp., or Ixodes tick infection;
- Reported tick abundance, Bbsl prevalence, or exposure indicators across urban, peri-urban, or rural settings.
Excluded studies:
- No urban/peri-urban stratification;
- No Borrelia-specific outcomes;
- Non-Ixodes focus / other tick-borne diseases;
- Study design not eligible;
- Non-European study;
- Non-English studies.
Data extraction and synthesis
Data on tick abundance, Bbsl prevalence, and environmental context were extracted. Urban risk patterns were classified into 5 categories: sustained transmission, comparable risk, elevated risk, reduced risk, or potential exposure, based on relative tick density and infection prevalence.
Limitations in sampling methodology and proxy outcomes were documented to contextualize surveillance gaps. Given the objectives of surveillance signal detection, studies relying on entomological and ecological proxy indicators were considered relevant sources of evidence. Disagreements were resolved by consensus among all authors.
Results
Comparative studies assessing tick abundance and Bbsl prevalence across urban, peri-urban, and rural environments are summarized in Table 1 and classified in Table 2.
Balážová et al. (2024) demonstrated widespread distribution of Bbsl across urban areas [9], while Ciebiera et al. (2024) revealed that pathogen prevalence in urban ticks may reach exceptionally high levels at specific locations [14]. Brzozowska et al. (2021) found that the frequency of infections was similar among urban and rural residents [15]. Mathews-Martin et al. (2020) reported substantially lower tick abundance in urban parks compared with peri-urban green spaces. The pronounced variability highlights strong spatial heterogeneity in tick exposure risk within urban settings, with peri-urban areas representing key transition zones [12]. Romiti et al. assessments demonstrated that tick populations infected with spotted fever group rickettsiae are present along commonly used park pathways. Although Bbsl was not detected in this sample, these findings underscore the importance of incorporating systematic risk assessment into urban tick-borne disease surveillance [13]. Sormunen et al. (2025) reported that almost all ticks collected from domestic cats and dogs were adults (99% of 14,889), highlighting differences between urban/peri-urban and natural tick populations [11].
Discussion
Surveillance-relevant urban risk signals presented in Table 2 were derived from the authors’ synthesis of reported tick abundance, Borrelia prevalence, and exposure indicators within each study included in Table 1.
The grouping and classification of factors are based on an interpretative synthesis of heterogeneous studies and are intended to facilitate comparison across different study designs and contexts.
Legend: Urban risk categories are based on tick density, Bbsl density, and human exposure.
- Sustained urban transmission: ongoing presence of infected ticks in multiple urban areas.
- Comparable risk: similar infection risk in urban and rural/peri-urban areas.
- Elevated urban risk: locally high infection rates or tick density in urban areas.
- Reduced urban risk: lower infection risk or tick density compared to rural/peri-urban areas.
- Potential urban exposure: possible contact with infected ticks, but no evidence of sustained transmission.
These categories highlight that urban risk is context-dependent and shaped more by local social and ecological factors than by urbanization per se. The descriptors “comparable”, “elevated”, or “reduced” urban risk refer to relative patterns observed within individual studies, rather than to direct quantitative comparisons across studies. The classification is intended as a heuristic surveillance tool rather than a reproducible quantitative metric. This approach mirrors how surveillance analysts interpret heterogeneous signal data in real-world settings.
Instead of following a linear decline in risk with increasing urbanization, LB exhibits a mosaic of localized exposure patterns. Tick density and Borrelia prevalence vary widely across urban locations, demonstrating the focal nature of risk. Urban areas frequently contain microhabitats in which infection risk is comparable to or even higher than in rural areas. Conversely, some urban green spaces exhibit markedly lower tick densities. Urban LB risk is increasing in relevance due to concurrent trends in urban greening, climate adaptation strategies, and changes in recreational behavior.
Where does Lyme borreliosis surveillance fail in urban Europe?
Although the European Centre for Disease Prevention and Control (ECDC) provides maps of tick distribution and tick surveillance activities in Europe, it does not currently publish integrated epidemiological maps of confirmed human LB cases or Bbsl infections at the EU/EEA level [16]. Consequently, current LB surveillance systems across Europe exhibit structural blind spots that systematically underestimate urban exposure and transmission. Key points of failure include:
Misclassification of exposure location
Peri-urban settlements represent a growing but frequently overlooked zone of increased infectious disease risk [17]. In routine surveillance, exposure is frequently recorded as “rural” or “unknown” by default, even when infection likely occurred in urban or peri-urban settings. This practice results in systematic misidentification of infection sources and masks urban transmission signals.
- Aggregation bias at national and regional levels
National-level reporting masks localized urban hotspots and prevents detection of fine-scale exposure patterns relevant for early warning and targeted interventions.
- Absence of routine urban entomological surveillance
Reliance on regional or national incidence data may obscure localized urban hotspots [1]. Tick monitoring is predominantly conducted in forests and rural habitats [16]. Urban green spaces, private gardens, and recreational areas are rarely included in routine surveillance.
- Clinician perception bias in urban settings
Clinicians in cities may be less likely to consider local tick exposure when evaluating compatible clinical presentations. LB is classically classified into three stages: early localized, early disseminated, and late. Most patients exhibit symptoms only during the early localized stage. Approximately 20% of cases progress to the early disseminated stage, mostly presented with multiple erythema migrans lesions. Other signs are less specific and may include headache, fatigue, myalgia, and arthralgia [1]. This may contribute to diagnostic delays. LB should be considered in the differential diagnosis even in patients without a clear history of rural exposure. Routine clinical assessment should include questions about time spent in urban green spaces, contact with pets, and other potential sources of tick exposure.
- Reliance on passive surveillance systems
Most European LB surveillance systems depend on passive case reporting. It captures clinically diagnosed cases but fails to detect emerging urban hotspots. The lack of integration between human, veterinary, and entomological data further limits early warning capacity.
These gaps contribute to the under-ascertainment of urban LB and impede accurate assessment of disease burden.
Implications for European Surveillance Systems
Synthesized evidence challenges traditional rural-focused prevention paradigms and underscores the need for urban-adapted public health strategies [18]. EU surveillance aims to ensure comparability, early detection, and situational awareness. Under Decision No 1082/2013/EU, EU Member States are required to ensure comparable epidemiological surveillance data to support early warning and risk assessment [19]. Additionally, active public involvement and data support environmental management of LB [18].
As suggested by the ECDC, integration of human, veterinary, and environmental data is essential to detect urban transmission hotspots and guide targeted interventions [16]. The involvement of domestic animals and urban-adapted wildlife highlights the importance of a One Health approach to LB prevention [11].
ECDC provides maps of tick distribution [16], focused predominantly on rural habitats. They do not integrate confirmed human cases or Bbsl prevalence in urban settings. To address these gaps, we recommend:
- Introduction of urban exposure as a mandatory reporting category;
- Systematic entomological monitoring in urban and peri-urban green areas;
- One Health approach to detect emerging urban hotspots and guide interventions.
Urban planning and green infrastructure initiatives should include vector-borne disease risk. Although urbanization often brings improvements in healthcare access, these benefits are unevenly distributed [17].
Procedures, such as wearing protective clothing, applying tick repellents, and performing regular tick checks, are essential to minimize occupational exposure [21]. Incorporating risk-aware vegetation management and informational measures in high-use areas may help reduce burden without compromising the benefits of urban nature [12]. Physicians are uniquely positioned to raise awareness of tick-borne diseases. Patient education should also address the availability of vaccination against selected tick-borne diseases. The fact that ticks transmit a broader range of pathogens beyond Bbsl should be emphasized.
Early diagnosis is challenging. Standard two-step serological testing is indirect and stage dependent. Accurate tools to evaluate patients are needed [20]. Standardizing diagnostic criteria and case definitions is crucial for generating reliable and comparable epidemiological data [1,15].
Introducing urban exposure categories would strengthen compliance with Decision No 1082/2013/EU and improve early warning capacity for LB in Europe. In the absence of such adaptations, current surveillance systems continue to misclassify exposure settings and underestimate the true risk of LB in increasingly urbanized populations.
Advantages and Limitations of The Study
The use of a scoping review methodology enabled the inclusion of diverse study designs and outcome measures, allowing identification of recurring patterns and knowledge gaps across heterogeneous studies. While not intended as a quantitative risk assessment, this approach supports structured comparison across studies and highlights the context-dependent nature of urban LB risk in Europe.
The interpretative classification of surveillance-relevant risk signaling patterns provides a structured framework for synthesizing complex findings, thereby supporting future research and informing urban public health planning.
By situating the findings within a One Health perspective, this paper integrates ecological and epidemiological domains and offers relevant insights for urban surveillance, risk communication, and clinical awareness.
Limitations of the study:
- Heterogeneous methods: Studies designs, tick measures, and outcomes vary, limiting direct comparisons.
- Proxy outcomes: Many use tick abundance or infection rates, not actual human cases.
- Subjective synthesis: “Urban risk” patterns are inferred without standardized thresholds.
- Language bias: Only English-language studies were included, potentially missing local evidence.
- Temporal gaps: Seasonal and annual variation in tick activity was inconsistently addressed.
Despite these limitations, the consistency of observed patterns across diverse settings supports the validity of the main conclusions.
Conclusions
Urban and peri-urban environments actively sustain infected tick populations. Human exposure risk can be comparable to, or greater than in rural areas. These findings challenge the traditional rural-focused model of Lyme borreliosis and call for One Health oriented strategies.
Failure to capture urban exposure leads to systematic under-ascertainment and misclassification of infection settings. We propose that urban exposure should be introduced as a mandatory reporting category in European Lyme borreliosis surveillance systems, aligned with ECDC case definitions.
Addressing Lyme borreliosis needs a multi-faceted approach to reduce transmission. Standardized monitoring and diagnostic protocols are essential to accurately assess infection risk and guide public health strategies.
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Ethical approval was not required for this review as it synthesizes data from previously published studies.
Color does not have to be used for any figures in print.
During the preparation of this work the authors used chatbox in order to improve the language. After using this tool, the authors reviewed and edited the content as needed and take full responsibility for the content of the published article.
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
source: https://www.sciencedirect.com/science/article/pii/S1201971226004169
(C) Lyme Borreliosis Foundation
