Evaluating the Ability of the Invasive Asian Longhorned Tick, Haemaphysalis longicornis, to Maintain and Transmit North American Tick-borne Viruses

评估入侵性亚洲长角蜱（长角血蜱）维持和传播北美蜱传病毒的能力

• 批准号: 10287181
• 负责人: Meghan Elizabeth Hermance
• 金额: $ 23.1万
• 依托单位: UNIVERSITY OF SOUTH ALABAMA
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-04 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10287181
• 关键词: Adult; Amblyomma; Ambylomma americanum; American; Animals; Asia; Asians; Awareness; Biology; Black-legged Tick; China; Climate; Country; Deer Tick; Development; Diagnostic; Disease; Epidemiology; Evaluation; Far East; Farming environment; Fever; Flavivirus; Functional disorder; Genus Phlebovirus; Geography; Goals; Haemaphysalis longicornis; Heartland virus; Horizontal Disease Transmission; Human; Indigenous; Infectious Skin Diseases; Kinetics; Leukopenia; Life; Measures; Mexico; Molecular; Molting; New Jersey; North America; Nymph; Outcome; Pacific Northwest; Population; Public Health; Quarantine; Reproduction; Research; Role; Salivary Proteins; Serology; Severe Fever with Thrombocytopenia Syndrome Virus; Sheep; Testing; Thrombocytopenia; Ticks; United States; Vertical Disease Transmission; Viral; Viremia; Virus; Virus Replication; Zoonoses; adverse outcome; base; falls; feeding; human disease; innovation; pathogen; predictive modeling; screening; surveillance study; tick population; tick transmission; tick-borne; tick-borne flavivirus; tick-borne virus; transmission process; transmission-blocking vaccine; vector; vector competence; viral transmission; virus host interaction

PROJECT SUMMARY & ABSTRACT The invasive Asian Longhorned tick, Haemaphysalis longicornis, is native to eastern Asia but recently established populations in the United States and continues to expand its geographic range. This is a public health threat, because in its native range, H. longicornis is an established vector of viruses closely related to Heartland virus (HRTV) and Deer tick virus (DTV), which are the two main North American tick-borne viruses. The capacity of H. longicornis to transmit North American tick-borne phleboviruses (HRTV) and flaviviruses (DTV) is unknown, leaving us unaware of the epidemiologic impact of this invasive tick species. The overall objective for this application is to assess the ability of H. longicornis to acquire, maintain, and transmit North American tick-borne phleboviruses and flaviviruses. The central hypothesis is that H. longicornis is a competent vector for HRTV and DTV, and co-feeding transmission of HRTV or DTV between infected native ticks and uninfected H. longicornis ticks can occur in the absence of host viremia. The rationale for this project is that if H. longicornis is capable of maintaining HRTV and DTV in tick populations and transmitting these viruses to mammalian hosts, we can begin to forecast evolving epidemiologic and transmission dynamics of these viruses in North America. The central hypothesis will be tested by pursuing two specific aims: 1) Assess the vector competence of H. longicornis ticks for HRTV and DTV; and, 2) Investigate whether non-viremic transmission of HRTV or DTV occurs between infected native ticks (Amblyomma americanum or Ixodes scapularis) co-feeding on the same host with uninfected H. longicornis. Under the first aim, H. longicornis will be infected with HRTV or DTV, and viral replication kinetics in the tick will be examined. To assess horizontal transmission of HRTV and DTV, infected H. longicornis will receive a bloodmeal and exposed hosts will undergo serology and viremia screening. After molting to the next life stage, ticks will be tested for the presence of virus to evaluate vertical transmission. For the second aim, uninfected H. longicornis nymphs will be co-fed on the same host with HRTV- infected A. americanum or DTV-infected I. scapularis adults. The H. longicornis nymphs will be tested for the presence of virus at different feeding proximities on the host. The proposed research is conceptually innovative because it is the first to evaluate H. longicornis’ vector competency for the North American viruses, HRTV and DTV, which circulate in regions where invasive H. longicornis populations recently established. This contribution will be significant because it frames the basic biology of this invasive tick species in relation to North American tick-borne viruses, which is extremely important as we seek to understand the public health implications of H. longicornis establishment in regions of North America where these viruses are endemic.

项目摘要和摘要 侵入性的亚洲长壁虱（Haemaphysalis longicornis）是东亚的原产地，但最近 在美国建立的人口，并继续扩大其地理范围。这是公众 健康威胁，因为在其本地范围内，H。Longicornis是与 Heartland病毒（HRTV）和鹿tick病毒（DTV）是北美主要的两个主要壁虱病毒。 H. longicornis传输北美tick虫的静脉病毒（HRTV）和黄病毒的能力 （DTV）未知，使我们没有意识到这种侵入性tick物种的流行病学影响。总体 此应用的目的是评估远离远北的H. longicornis的能力 美国tick传播的静脉病毒和黄病毒。中心假设是H. longicornis是一个有能力的 HRTV和DTV的向量，以及在受感染的本地壁虱和DTV的共同进媒体传播 在没有宿主病毒血症的情况下，可能会发生未感染的longicornis tick虫。该项目的理由是，如果 H. longicornis能够在壁虱种群中维持HRTV和DTV，并将这些病毒传播到 哺乳动物宿主，我们可以开始预测这些病毒的流行病学和传播动态 在北美。中心假设将通过追求两个具体目标来检验：1）评估矢量 H. longicornis tick的能力在HRTV和DTV中； 2）调查是否非侵犯性传播 HRTV或DTV发生在感染的本地壁虱（Amblyomma Americanum或Ixodes capularis）之间 在与未感染H. longicornis的同一宿主上。在第一个目标下，H。Longicornis将被HRTV感染或 将检查tick中的DTV和病毒复制动力学。评估HRTV的水平传播和 DTV，感染的H. longicornis将获得血液的伴侣，暴露的宿主将患血清学和病毒血症 筛选。在分s下一个生命阶段后，将测试tick虫的存在，以评估垂直的病毒 传播。在第二个目标中，未感染的远科氏二若虫将与HRTV-一起在同一宿主上共馈 感染的A. ameriverum或DTV感染的I.肩cap骨成年人。 H. longicornis若虫将进行测试 病毒在宿主的不同喂养持续性处存在。拟议的研究在概念上是创新的 因为它是第一个评估H. longicornis的媒介能力的北美病毒，HRTV和 DTV，该区域在侵入性H. longicornis种群最近成立的地区。这个贡献 这将是重要的，因为它构成了这种侵入性壁虱物种与北美有关的基本生物学 tick传播病毒，这非常重要，因为我们试图了解H的公共卫生影响。 朗西尼（Longicornis）在北美地区建立了这些病毒是内在的地区。