Landscape ecology of the deer tick and its associated Lyme disease pathogen

莱姆病是由伯氏疏螺旋体细菌引起的，该细菌由一系列脊椎动物宿主携带，并通过受感染的蜱虫媒介传播给人和动物。在加拿大，莱姆病的发病率正在迅速增加，这与鹿蜱（肩胛骨蜱）向北扩展的范围有关。尽管莱姆病在加拿大许多地区日益重要，但莱姆病生态学的许多方面仍不清楚，特别是在最近引进的地区。这包括了解蜱和病原体的地理分布，不同物种作为蜱和莱姆病宿主的重要性，以及蜱和病原体在景观尺度上的传播途径。本研究旨在：1)通过野外调查，确定伯氏疏螺旋体在散养哺乳动物和蜱类中的宿主范围和流行情况；2)通过生态建模了解水库宿主、媒介和病原体生态位的生态决定因素；3)通过分子研究表征宿主、媒介和病原体的遗传多样性；4)利用群体遗传学和景观遗传学研究蜱虫和莱姆病传播的潜在途径。为了更好地了解莱姆病在位于鹿蜱入侵北部前沿的城郊环境中的生态和传播，我提出的研究将结合宿主和蜱虫媒介的实地研究，宿主、媒介和病原体的分子和遗传特征，以及空间和统计建模。这些研究将增加我们对小型哺乳动物宿主和蜱虫媒介参与伯氏疏螺旋体传播和传播的认识，并揭示环境因素如何影响莱姆病的传播模式。此外，这些研究将确定与最近莱姆病传入地区的鹿蜱和伯氏疏螺旋体传播相关的因素。值得注意的是，这项研究将有助于为媒介传播的疾病监测和控制战略提供信息，这将最终减少疾病传播并预防家畜和人类中的感染。

Lyme disease is caused by the bacterium Borrelia burgdorferi, which is carried by a range of vertebrate reservoir hosts and transmitted to people and animals by infected tick vectors. In Canada, the incidence of Lyme disease is increasing rapidly in association with the northward range expansion of the deer tick (Ixodes scapularis). Despite the growing importance of Lyme disease in many parts of Canada, many aspects of Lyme disease ecology remain unclear, especially in areas of recent introduction. This includes knowledge on the geographic distribution of the tick and pathogen, the importance of different species as hosts for ticks and Lyme disease, and the pathways of tick and pathogen spread at the landscape scale. This research aims to: 1) determine the host range and prevalence of B. burgdorferi in free-ranging mammals and ticks through field studies; 2) understand the ecological determinants of reservoir host, vector and pathogen niche through ecological modelling; 3) characterize the genetic diversity of reservoir hosts, vectors and pathogens through molecular studies; and, 4) investigate potential pathways of tick and Lyme disease spread using population and landscape genetics. My proposed research combines field studies of reservoir hosts and tick vectors, molecular and genetic characterization of reservoir hosts, vectors and pathogens, and spatial and statistical modelling in order to better understand Lyme disease ecology and spread in peri-urban environments situated at the northern range front of deer tick invasion. These studies will increase our understanding of the involvement of small mammal reservoir hosts and tick vectors in B. burgdorferi transmission and spread, and reveal how Lyme disease transmission patterns are affected by environmental factors. Furthermore, these studies will identify factors associated with the spread of deer ticks and B. burgdorferi in a region of recent Lyme disease introduction. Notably, this research will help to inform vector-borne disease surveillance and control strategies, which will ultimately reduce disease spread and prevent infections in domestic animals and humans.