Does ecological connectivity drives tick abundance and pathogen presence in urban parks

Abstract

Introduction. Urban green spaces represent potential hotspots for tick-borne disease transmission. In Chișinău, the capital of Moldova, numerous parks serve as habitats for Ixodes ricinus and other tick species. However, the influence of ecological connectivity on tick abundance and pathogen circulation in these urban ecosystems has not been systematically studied. Purpose of the study. O assess how ecological connectivity and landscape composition influence tick abundance and pathogen presence in urban parks of Chișinău. Material and methods. Ticks were collected by flag-dragging in six urban parks during spring 2021–2022. Species were identified morphologically, and DNA was extracted for real-time PCR screening using AmpliSens® multiplex assays targeting Borrelia burgdorferi s.l., Anaplasma phagocytophilum, Ehrlichia chaffeensis/E. muris, and tick-borne encephalitis virus. Parks were categorized as “connected” (linked to external natural areas) or “isolated” (surrounded by urban structures). Environmental parameters such as artificial surface cover, tree canopy, mowing frequency, and stray dog abundance were recorded. Data were analyzed using multiple and logistic regression models. Results. A total of 519 ticks were collected, belonging to four species: I. ricinus (67.4%), Dermacentor reticulatus (22.1%), D. marginatus (9.6%), and Haemaphysalis punctata (0.9%). Connected parks yielded 84% of all ticks, with a mean density over fourfold higher than isolated parks. Pathogen DNA was detected in 17.9% of ticks, predominantly Borrelia burgdorferi s.l. (11.6%), Anaplasma phagocytophilum (4.4%), and Ehrlichia spp. (1.9%). Infection prevalence was significantly higher in connected parks (20%) compared to isolated ones (6%) (χ², p = 0.002). Regression analysis indicated that artificial surface fraction negatively correlated with tick abundance (p = 0.002), while ecological connectivity remained a significant predictor of pathogen presence (OR = 3.74, p = 0.019). Conclusions. Ecological connectivity strongly enhances both tick density and pathogen prevalence in urban parks of Chișinău. However, urban landscape features such as artificial surface cover and vegetation structure also play key roles. Integrating ecological and management variables is essential for assessing tick-borne disease risk in cities. Surveillance and preventive measures should prioritize highly connected parks bordering natural areas.