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1. Introduction
Human alteration of natural ecosystems is now evident on more of 75% of the Earth’s ice-free land mass as a result of urbanization, agricultural and other land uses, with less than a quarter remaining as intact habitats [1]. Urbanization, in particular, has increased worldwide in recent decades and more than half of the world’s population now lives in urban areas, with the expectation that 66% will live in urban areas by 2050 [2,3].
Human land use and exploitation of natural ecosystems represent one of the major drivers of zoonotic disease emergence by disrupting disease dynamics and cross-species transmission in multi-host, multi-pathogen systems (‘perturbation hypothesis’) and/or by increasing exposure of hosts to novel pathogens (‘novel pathogen pool hypothesis’) [4]. However, understanding the mechanisms by which land use change leads to disease emergence is still rudimentary.
Vector borne diseases, and in particular those transmitted by ticks, appear to be particularly sensitive to land use changes [5] and, therefore, they represent a valuable model to quantify the indirect impact of anthropization and land use changes on human and animal health.
The widespread occurrence of the castor bean tick, Ixodes ricinus in Europe, and the pathogens it transmits, together with the rise of clinical cases of tick-borne diseases (TBDs) in humans and livestock, have made TBDs one of the major One Health issues in recent years [6]. I. ricinus has a broad ecological plasticity and capacity to exploit anthropic landscapes, and its distribution has increased in the last three decades as a result of more favorable biotic and abiotic conditions [5]. Concomitantly, the annual incidences of bacterial diseases such as Lyme borreliosis and rickettsiosis have also increased steadily [7,8]. Several authors have suggested that the prediction of ‘acarological hazard’ in different habitat conditions could be useful to public health authorities for planning and implementing targeted educational and preventive actions for TBDs [9,10]. Hazard is defined in epidemiological risk assessment procedures as “the set of circumstances that could lead to harm” [11], i.e., in this case, the occurrence within natural enzootic cycles of certain tick-borne pathogens (TPBs) with known pathogenic potential. In turn, “risk is the actual exposure of susceptible hosts to TBPs” [11] that takes into account the interaction between infected ticks and humans [11]. The acarological...