Evaluating Effect of Woody Plant Encroachment on Tick-borne Pathogens in the South Central United States

评估美国中南部木本植物入侵对蜱传病原体的影响

• 批准号: 10553162
• 负责人: Scott Loss
• 金额: $ 7.27万
• 依托单位: OKLAHOMA STATE UNIVERSITY STILLWATER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-20 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10553162
• 关键词: Address; Affect; Amblyomma; Ambylomma americanum; Area; Arthropods; Biomass; Characteristics; Chronic Disease; Communities; Deer; Deforestation; Dermacentor; Disease; Domestic Animals; Ecology; Ecosystem; Ehrlichia; Ehrlichia chaffeensis; Ehrlichia ewingii; Ehrlichiosis; Environmental Impact; Future; Goals; Grasslands; Health; Health Resources; Human; Humidity; Incidence; Individual; Infection; Influentials; Invaded; Investigation; Juniperus virginiana; Kansas; Knowledge; Link; Lyme Disease; Microclimate; Modeling; Oklahoma; Outcome; Pattern; Personal Satisfaction; Pilot Projects; Plants; Prevalence; Public Health; Research; Rickettsia; Rickettsia Infections; Role; Sampling; Site; System; Tail; Temperature; Testing; Texas; Tick Control; Tick-Borne Diseases; Ticks; Trees; United States; Urbanization; Vector-transmitted infectious disease; Work; density; disorder risk; environmental change; forest; human disease; improved; innovation; land cover; non-Native; pathogen; spatiotemporal; spotted fever; tick-borne pathogen; transmission process; vector; vector tick; virtual

PROJECT SUMMARY/ABSTRACT The south-central U.S. has among the highest human incidences of tick-borne diseases (TbDs) like spotted fever group rickettsiosis and Ehrlichiosis. Yet, it is one of the least-studied regions with regard to the ecology of tick species and hosts, and their associations with human-caused environmental change. A pervasive form of human-caused land cover change ongoing globally, including in the south-central U.S., is encroachment of woody plants in grasslands and shrublands (woody plant encroachment; WPE). WPE’s ecological impacts (e.g., alteration of microclimates and arthropod communities) mirror mechanisms by which other land cover changes influence transmission of pathogens, including tick-borne pathogens (TbPs). However, WPE’s wholesale transformation of ecosystems makes it fundamentally different from other well-studied woody cover changes like deforestation and non-native shrub invasions in forests. A virtually unstudied consequence of WPE is its potential foundational role in influencing distributions of tick vectors and spatiotemporal patterns of TbP transmission. Our long-term goal is to clarify how WPE affects tick-borne diseases in the south-central U.S., and to apply this knowledge to better predict human disease risk and target public health resources and WPE management that benefit human health. Our overall aim is to assess relationships between WPE by eastern redcedar (ERC; Juniperus virginiana), the primary encroaching species in the south-central U.S, and TbP transmission systems in Oklahoma (where WPE extent is 5-7x greater than elsewhere in the U.S.). Our central hypothesis is that the many WPE-caused changes to ecosystems facilitate spatial expansion and persistence of key tick vectors and increase rates of vector infection for multiple pathogens. To address this hypothesis, we propose 2 objectives: 1) Quantify tick abundance and diversity relative to ERC encroachment; and 2) Evaluate links between TbP infection prevalence and ERC encroachment. Preliminary studies indicate that numbers of key tick species (Amblyomma americanum & Dermacentor variabilis), and of ticks infected with SFG rickettsia and Ehrlichia spp., are higher with ERC encroachment. This study will include 2 years of field sampling ticks at 40 sites representing 4 ERC encroachment stages, including control sites with no ERC. Ticks will be identified and tested for 5 pathogen groups, and we will analyze whether ERC stage is related to tick diversity, abundance, and TbP prevalence. This study is innovative because no research globally has considered effects of WPE under a whole-disease system framework. Addressing our objectives will increase understanding of WPE’s impact on ticks and TbP transmission dynamics; future research will address other mechanisms including WPE effects on reservoir hosts and tick-host interactions. This study will provide critical information that improves public health by informing tick control strategies based on assessment of land cover characteristics, and by focusing distribution of public health resources and enactment of WPE management.

项目摘要/摘要 美国中南部拥有tick传播疾病（TBD）的最高人类造成 发烧组立克氏病和ehrlichiosis。然而，它是关于生态学最不研究的地区之一 壁虱物种和宿主及其与人为引起的环境变化的关联。普遍的形式 在全球范围内，包括美国中南部在内的全球持续发生的土地覆盖范围是侵占 草原和灌木丛中的木本植物（木本植物侵占； WPE）。 WPE的生态影响 （例如，微气候和节肢动物社区的改变）其他土地覆盖物的镜像机制 变化会影响病原体的传播，包括tick传播病原体（TBP）。但是，WPE的 生态系统的批发转化使其与其他研究的木质封面根本不同 森林中的森林砍伐和非本地灌木入侵等变化。几乎没有研究的结果 WPE是其在壁虱向量和时空模式的影响分布中的潜在基础作用 TBP传输。我们的长期目标是阐明WPE如何影响中南部的tick传播疾病 美国，并运用这些知识来更好地预测人类疾病的风险并针对公共卫生资源和 受益于人类健康的WPE管理。我们的总体目的是评估WPE之间的关系 东部redcedar（ERC; Juniperus Virginiana），美国中南部的主要侵占物种， 俄克拉荷马州的TBP传输系统（WPE范围比美国其他地方大5-7倍）。我们的 中心假设是生态系统的许多WPE引起的变化有助于空间扩张和 键tick矢量的持久性和增加多种病原体的矢量感染率。解决这个问题 假设，我们提出了2个目标：1）量化相对于ERC加密的刻度抽象和多样性； 2）评估TBP感染率和ERC加密之间的联系。初步研究表明 关键的壁虱物种（Amblyomma Americanum＆Dermacentor variabilis）和被感染的壁虱 ERC侵占，伴有SFG人力素和ehrlichia spp。这项研究将包括2年 代表4个ERC加密阶段的40个站点​​的现场采样刻度，包括没有ERC的控制位点。 tick将被识别并测试5个病原体，我们将分析ERC阶段是否与 tick多样性，抽象和TBP患病率。这项研究具有创新性，因为全球没有研究 在整个疾病系统框架下考虑了WPE的效果。解决我们的目标将增加 了解WPE对壁虱和TBP传输动态的影响；未来的研究将解决其他 包括WPE对储层宿主和tick-host相互作用的机制。这项研究将提供关键 通过基于土地覆盖的评估来告知tick控制策略来改善公共卫生的信息 特征，并通过关注公共卫生资源的分配和WPE管理的颁布。