Ecological impacts of forest disturbance on La Crosse encephalitis virus dynamics

森林干扰对拉克罗斯脑炎病毒动态的生态影响

• 批准号: 7754503
• 负责人: Maria-Richetta Camille Harris
• 金额: $ 3.02万
• 依托单位: VIRGINIA POLYTECHNIC INST AND ST UNIV
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7754503
• 关键词: Antibodies; Antigens; Arboviruses; Area; Asians; Biological Assay; Birds; Blood; Centers for Disease Control and Prevention (U.S.); Child; Childhood; Communities; Competence; Complex; Culex pipiens; Culicidae; DNA; Disease; Disease Outbreaks; Ecological Change; Encephalitis; Encephalitis Viruses; Environmental Impact; Feeding behaviors; Goals; Habitats; Human; Hybrids; Incidence; La Crosse virus; Language; Life; Mammals; Mid-Atlantic Region; Modeling; Mosquito Control; Neurologic; Neutralization Tests; Orthobunyavirus; Patient currently pregnant; Pattern; Prevalence; Rift Valley Fever; Rodent; Sampling; Self-Sustained Sequence Replication; Site; Techniques; Testing; United States; Viral; Virginia; Virus; West Virginia; biosafety level 2 facility; density; environmental change; enzootic; feeding; forest; human disease; land use; predictive modeling; preference; research study; transmission process; vector; vector mosquito; yeast two hybrid system

DESCRIPTION (provided by applicant): La Crosse encephalitis virus (LAC), a devastating neurologic disease in children living in endemic areas like West Virginia and southwestern Virginia, is maintained through interactions between mosquito vectors and non-human vertebrate reservoir hosts in forests. Changes to interior forest habitat may impact viral dynamics leading ultimately to human disease outbreaks. Forest canopy disturbance (FCD) due to logging is rapidly increasing worldwide, with unknown potential impacts on arboviral transmission dynamics. We hypothesize that FCD will result in ecological changes that ultimately amplify LAC prevalence by altering enzootic transmission cycles. To test this hypothesis, we propose 4 studies: (1) FCD effects on mosquito vector and vertebrate host communities, (2) FCD effects on mosquito host-feeding behavior, (3) LAC vector competence of Cx. pipiens/quinquefasciatus hybrids in southwestern Virginia, and (4) natural prevalence of LAC across FCD study sites. The field component of this study will occur on three replicates of experimental forest disturbance regimes (undisturbed control, intermediate disturbance, and extreme disturbance) in southwestern Virginia. CDC gravid traps will be used to collect mosquitoes and estimate the abundance of native and introduced vector species across FCD sites. Live trapping of small mammals and point counts will be performed to assess the vertebrate community across disturbance regimes. DNA barcoding of mosquito blood meals will be used to determine host-feeding preferences of mosquitoes across the plots. Vector competence studies of Cx. hybrids will be performed in a BSL-2 facility that includes an insectory. A nucleic acid sequence-based amplification assay for LAC will be used to detect antigen in mosquitoes. Plaque reduction neutralization tests will be employed to assess LAC antibody prevalence in mammals. Our long-term goal is to use a mechanistic understanding of how land use change impacts LAC transmission dynamics to develop a predictive model. Such a model can help focus LAC mosquito control efforts and ultimately identify patterns applicable to other emerging bunyaviruses like Rift Valley fever. LAY LANGUAGE: As humans change the landscape, we may be altering disease dynamics. La Crosse encephalitis virus is maintained in forest through interactions between mosquitoes and small mammals. This study aims to determine how different logging techniques may impact the abundance of mosquitoes, small mammals and virus as well as mosquito feeding behavior. We will also perform experiments to assess how efficiently mosquito species can transmit this virus.

描述（由申请方提供）：拉克罗斯脑炎病毒（LAC）是一种生活在西弗吉尼亚州和弗吉尼亚州西南部等流行地区的儿童中的毁灭性神经系统疾病，通过蚊子媒介与森林中的非人类脊椎动物储库宿主之间的相互作用维持。森林内部栖息地的变化可能会影响病毒动态，最终导致人类疾病爆发。森林冠层干扰（FCD）由于伐木在世界范围内迅速增加，对虫媒病毒传播动力学的潜在影响未知。我们假设，FCD将导致生态变化，最终放大LAC的流行，改变地方性流行病的传播周期。为了验证这一假设，我们提出了4个研究：（1）FCD对蚊媒和脊椎动物宿主群落的影响，（2）FCD对蚊子宿主取食行为的影响，（3）Cx的LAC载体能力。pipiens/quinquefasciatus杂种在弗吉尼亚州西南部，和（4）自然流行的LAC整个FCD研究地点。本研究的现场部分将发生在弗吉尼亚州西南部的三个重复的实验性森林干扰制度（不受干扰的控制，中间干扰，极端干扰）。CDC妊娠诱捕器将用于收集蚊子，并估计FCD地点的本地和引入病媒物种的丰度。将进行小型哺乳动物的现场诱捕和点计数，以评估整个干扰制度下的脊椎动物群落。蚊子血粉的DNA条形码将用于确定整个地块中蚊子的宿主进食偏好。Cx的载体能力研究。杂交将在BSL-2设施中进行，其中包括昆虫。将使用基于核酸序列的LAC扩增试验检测蚊子中的抗原。将采用空斑减少中和试验评估哺乳动物中LAC抗体的流行率。我们的长期目标是使用土地利用变化如何影响LAC传输动态的机械理解，以开发预测模型。这样的模型可以帮助集中LAC蚊子控制工作，并最终确定适用于其他新兴布尼亚病毒（如裂谷热）的模式。通俗语言：随着人类改变景观，我们可能正在改变疾病动态。拉克罗斯脑炎病毒通过蚊子和小型哺乳动物之间的相互作用在森林中维持。这项研究旨在确定不同的伐木技术如何影响蚊子，小型哺乳动物和病毒的丰度以及蚊子的喂养行为。我们还将进行实验，以评估蚊子传播这种病毒的效率。