RCG Culex distribution, vector competence and threat of transmission of arboviruses to humans and animals in the UK

几十年来，英国人和动物首次受到蚊媒疾病的威胁。在过去的10-15年里，我们目睹了两种蚊子入侵英国。气候与我们相似的北欧部分地区正在经历蚊媒疾病，这种疾病可能很快会传播到英国。研究表明，如果提供机会，我们的一些本土蚊子物种可能会传播疾病。这种快速变化的情况可能是一系列因素的综合作用，包括气候变化(使蚊子能够占据新的地区并在其中传播疾病)以及越来越多的旅行和贸易，从而促进它们的传播。虽然大多数人都熟悉蚊子是疟疾寄生虫向人类传播的媒介，但蚊子也是许多不同病毒对人类和动物的重要传播者。蚊媒病毒的威胁是这项提案的重点。特别是，我们重点关注过去几年在北欧传播到人和动物并导致其患病的两种非洲病毒：西尼罗河病毒和乌苏图病毒。这两种病毒都是通过不同类型的库蚊传播的，这些蚊子包括常见的家蚊，一种在英国各地发现的本地物种，也包括某些入侵物种。为了准备应对西尼罗河或乌苏图未来在人和/或动物中爆发的疾病，我们想要了解病毒传播的风险，以及它在英格兰和威尔士可能会发生什么变化。了解这一风险将使我们能够识别风险较高或较低的年份或地区，并可能使控制措施成为目标。为了实现这一目标，我们将在英格兰和威尔士进行第一次全国性的库蚊调查。它们的分布在很大程度上是由它们繁殖的水体的性质决定的，我们将对它们进行描述。在英国建立这种病毒需要以鸟类(鸟类是病毒的自然宿主)为食的蚊子；而对人类/牲畜/同伴动物的威胁来自蚊子从鸟类感染，然后以哺乳动物为食。我们将通过分子方法来测量不同蚊子的取食偏好，以确定它们最后一次吸血的来源。病毒传播风险还要求蚊子能够感染病毒，然后通过唾液传播病毒；我们将在英国夏季典型的温度体系和一些更极端的条件下对这种能力(称为媒介能力)进行量化。最后，我们将把这些不同的数据集整合到一个创新的建模框架中，这将使我们能够绘制出英格兰和威尔士不同的风险水平，并显示这种风险可能会随着时间的推移而变化。一旦实现，这个项目将使英国在应对蚊媒病毒的威胁和应对疾病爆发方面处于更有利的地位，如果它们在未来发生--而且更有可能发生--。

The people and animals of the UK are threatened by mosquito-borne diseases for the first time in several decades. In the last 10-15 years we have witnessed two species of mosquito invade the UK. Parts of northern Europe with climates similar to our own are experiencing mosquito-borne disease which may imminently spread to the UK. And research has shown that some of our native mosquito species may be able to spread diseases, if provided the opportunity. The rapidly changing situation is likely due to a combination of factors including climate change (enabling mosquitoes to occupy new areas and transmit diseases in them) and ever greater volumes of travel and trade, facilitating their spread.While most people are familiar with mosquitoes as transmitters of malaria parasites to humans, mosquitoes are also important as transmitters of many different viruses to both humans and animals. The threat from mosquito-borne viruses is the focus of this proposal. In particular, we focus on two African viruses that have spread to, and caused disease in humans and animals, in northern Europe in the last few years: West Nile virus and Usutu virus. Both viruses are transmitted by types of Culex mosquito - these include the common house mosquito, a native species found across the UK, and also certain invasive species.To prepare for future disease outbreaks - in people and/or animals - of West Nile or Usutu, we want to develop an understanding of the risk of virus transmission and how it may vary across England and Wales. Understanding this risk will enable us to identify years or areas of higher or lower risk and may enable the targeting of control measures.To achieve this we will undertake the first national surveys for Culex mosquitoes across England and Wales. Their distributions are, in large part, determined by the nature of the water bodies in which they breed and we will characterise these. The establishment of the viruses in the UK requires mosquitoes that feed on birds (which are the natural hosts of the viruses); and threat to humans/livestock/companion animals arises from mosquitoes that become infected from a bird and then feed on mammals. We will measure the feeding preferences of the different Culex mosquitoes by using molecular methods to identify the sources of their last bloodmeal. Virus transmission risk also requires mosquitoes that are capable of being infected with virus, and then transmitting it in saliva; we will quantify this (termed vector competence) at temperature regimes typical of the UK summer and some more extreme conditions. Finally, we will integrate these different datasets into an innovative modelling framework that will enable us to map the different levels of risk across England and Wales and show how this may vary over time.Once achieved, this project will put the UK in a much stronger position for addressing the threat of mosquito-borne viruses and tackling disease outbreaks if - and more likely 'when' - they occur in the future.