Vector-borne transmission of lumpy skin disease virus

疙瘩状皮肤病病毒（LSDV）是疙瘩状皮肤病（LSD）的病原体，后者是非洲和中东牛的一种地方病，在那里造成重大经济损失并成为贸易壁垒。自2012年以来，LSDV已经蔓延到土耳其、欧洲、高加索和俄罗斯。这一流行病导致成千上万头牛被屠宰、大规模疫苗接种运动、动物流动限制和出口禁令。阻碍控制工作的关键知识差距之一是对LSD如何在动物之间和畜群之间传播的理解。近年来，LSD专家小组和许多LSD主题研讨会都将LSD病媒传播的研究确定为高度优先事项。这将在本研究项目中解决。该项目的假设是：可存活的LSDV在适当地点的昆虫媒介中持续存在，并有足够的时间允许向数百公里外的牛传播。这项拟议的工作涉及两个在18个月内并行运行的目标。目的1确定LSDV最可能传播的媒介群。这一目标将在皮尔布赖特研究所的高度封闭设施中，通过潜在的昆虫媒介对受感染的牛进行LSDV传播的实验。这些研究将使用现代病毒检测技术来区分机械传播和生物传播，并估计欧洲存在的不同昆虫媒介的风险。调查四种昆虫的传播媒介潜力，分别是稳定蝇、棕纹库蚊、埃及伊蚊和致倦库蚊。选择这四个物种的依据是它们在受影响和/或受威胁地区的分布、它们与LSDV传播的实验或流行病学联系的文献证据，以及它们代表不同的摄食机制（螺线虫和端食虫）。目的2评估LSDV的风险及不同控制措施的潜在影响。本目标将把实验结果整合到LSDV模型中，从而探索不同控制措施的疾病风险和影响。总体而言，该项目将提供LSDV病媒传播的科学证据，以便能够设计有效和成比例的LSDV控制方案，并遏制目前欧亚LSDV流行病。该项目利用Pirbright在块状皮肤病研究、家畜病毒性疾病的多尺度建模、吸血昆虫生物学、自然反刍动物宿主与媒介之间病毒的体内传播研究以及节肢动物的尖端生物成像等方面的独特和世界级专业知识，研究LSDV的媒介传播。该项目由工业合作伙伴MSD动物保健公司赞助，该公司是广泛使用的抗LSD Lumpyvax疫苗的生产商。MSD动物卫生部门正在与Pirbright合作开展这一项目，使LSDV疫苗接种运动能够通过科学合理的控制规划得到加强，旨在减少LSDV病媒传播。这种方法符合默克动物保健公司的理念，即他们的责任超出了他们的主要业务目标。通过支持这一研究项目，他们的目标是为控制和根除LSD的努力增加价值，从而为环境和整个更广泛的社会带来好处。该项目也得到了DEFRA的支持，DEFRA是英国政府部门，负责保护英国免受诸如疙瘩性皮肤病（LSD）等外来疾病的侵害。这种支持强调了这项研究将对降低LSD入侵英国的风险产生的影响，并在它确实发生时促进其迅速根除。

Lumpy skin disease virus (LSDV) is the causative agent of lumpy skin disease (LSD), an endemic disease of cattle in Africa and the Middle East where it produces significant economic loss and acts as a barrier to trade. Since 2012 LSDV has spread into Turkey, Europe, the Caucasus and Russia . The epidemic has resulted in the slaughter of thousands of cattle, mass vaccination campaigns, animal movement restrictions and export bans. One of the key knowledge gaps hampering control efforts is an understanding of how LSD is transmitted from animal to animal and herd to herd. LSD expert panels and numerous LSD-themed workshops in recent years have all identified research into vector-borne transmission of LSD as a high priority. This will be addressed in this research project.The project hypothesis is:Viable LSDV persists in insect vectors at suitable sites and for sufficient time to allow onward transmission to cattle hundreds of kilometres distant.This proposed work involves two objectives running in parallel over 18 months. Objective 1 To identify the most likely vector group responsible for transmission of LSDV. This objective will undertake experimental transmission of LSDV from infected cattle by potential insect vectors in the high containment facilities at The Pirbright Institute. These studies will use contemporary virus detection techniques to distinguish between mechanical and biological transmission, and estimate the risk of different insect vectors that are present in Europe. The vector potential of four insect species, Stomoxysis calcitrans (stable flies), Culicoides nubeculosus midge, and Aedes aegypti and Culex quinquefasciatus mosquitoes, will be investigated. The four species were each selected on the basis of their distribution in affected and / or threatened areas, evidence from the literature of their experimental or epidemiological link to LSDV transmission, and because they represent different feeding mechanisms (solenophagous vs telmophagous).Objective 2 To assess the risk posed by LSDV and the potential impact of different control measures.This objective will integrate the experimental results into models of LSDV and, hence, explore the risk of disease and impact of different control measures. Overall the project will provide scientific evidence on vector-borne transmission of LSDV to enable effective and proportional LSD control programmes to be designed and the current Eurasian LSD epidemic to be contained.The project utilises the unique and world-class expertise at Pirbright in lumpy skin disease research, multi-scale modelling of viral diseases of livestock, the biology of blood-feeding insects, in vivo transmission studies of viruses between natural ruminant hosts and vectors, and cutting-edge bioimaging of arthropods to study vector-borne transmission of LSDV. The project is sponsored by an industrial partner MSD Animal Health, producer of the widely used Lumpyvax vaccine against LSD. MSD Animal Health are partnering Pirbright in this project to enable LSD vaccination campaigns to be augmented with scientifically rational control programmes aimed at reducing vector-borne transmission of LSDV. This approach is in accordance with Merck Animal Health's philosophy that their responsibilities extend beyond their primary business goals. By supporting this research project they aim to add value to efforts to control and eradicate LSD and thereby provide benefit to the environment and wider society as a whole.The project is also supported by DEFRA, the UK government department responsible for protecting the UK from exotic diseases such as lumpy skin disease (LSD). This support emphasises the impact this research will have on reducing the risk of LSD incursion into the UK, and facilitating its rapid eradication if it does occur.