Ecological impacts of forest disturbance on La Crosse encephalitis virus dynamics

描述(申请人提供)：拉克罗斯脑炎病毒(LAC)是一种居住在西弗吉尼亚州和弗吉尼亚州西南部流行地区的儿童的毁灭性神经疾病，通过蚊子媒介和森林中非人类脊椎动物水库宿主之间的相互作用来维持。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。由于采伐引起的森林冠层干扰(FCD)正在全球范围内迅速增加，对虫媒病毒传播动态的潜在影响尚不清楚。我们假设，FCD将导致生态变化，最终通过改变地方性传播周期放大LAC的流行。为了验证这一假设，我们提出了4项研究：(1)FCD对蚊媒和脊椎动物宿主群落的影响；(2)FCD对蚊子寄主取食行为的影响；(3)CX的LAC媒介能力。(4)在FCD研究地点的LAC自然流行率。这项研究的现场部分将发生在弗吉尼亚州西南部的三个实验森林干扰制度(未受干扰的控制、中等干扰和极端干扰)的重复上。CDC将使用妊娠诱捕器收集蚊子，并估计FCD地点本地和引进的媒介物种的丰度。将进行小型哺乳动物的活体诱捕和点数，以评估不同干扰区域的脊椎动物群落。蚊子血粉的DNA条形码将被用来确定蚊子在整个地块的寄主取食偏好。Cx.的媒介能力研究。混合动力车将在BSL-2设施中进行，其中包括昆虫室。一种基于核酸序列的LAC扩增分析将被用于检测蚊子的抗原。将使用空斑减少中和试验来评估哺乳动物中LAC抗体的流行率。我们的长期目标是利用对土地利用变化如何影响LAC传播动态的机械性理解来开发一个预测模型。这样的模型可以帮助集中拉丁美洲和加勒比地区的蚊子控制工作，并最终确定适用于其他新出现的本雅热病毒的模式，如裂谷热。通俗语言：随着人类改变地貌，我们可能正在改变疾病的动态。拉克罗斯脑炎病毒是通过蚊子和小型哺乳动物之间的相互作用在森林中维持的。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数量以及蚊子的取食行为。我们还将进行实验，以评估蚊子物种传播这种病毒的效率。

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.