Usutu virus risk to the UK: Determining local vector competence and modelling climate suitability

病毒感染并导致某些野生鸟类（如黑鸟和乌鸦）的大规模死亡;但近年来，它已被认为是人畜共患病，感染人，并引起发烧，在某些情况下，神经侵入性疾病，如脑炎和脑膜脑炎。病毒通过蚊子传播，并在整个欧洲出现。2020年温暖的夏季，在大伦敦地区的两种野生鸟类中检测到人畜共患的蚊媒登革热病毒。此外，在非迁徙家雀中，在很长一段时间内都检测到了埃因霍温病毒，这强烈表明该病毒已经在英国定居，英国当地的蚊子正在传播它。埃因霍温病毒在欧洲的主要蚊媒是北方家蚊，它存在于英国，主要以鸟类为食。最近的研究表明，该物种的实验室菌落能够在温暖的温度下传播病毒。因此，我们的本地蚊子可能因此能够传播它。此外，在英国存在的其他种类的蚊子既以鸟类也以人类为食，因此可能能够将病毒从鸟类宿主传播给人类。目前尚不清楚这些物种在野生环境中传播登革热病毒的能力。本提案的总体目标是评估在英国实际温度下，当地和入侵性蚊子将登革热病毒传播给鸟类和人类对英国的风险。利用这些结果，我们将数学模型的英国气候的适合性，结合当地蚊子和水库鸟类的地理范围的数据。这将产生风险地图，显示出在哪里以及何时能够在英国传播登革热病毒。在这个项目结束时，我们将收集到大量关于登革热病毒和我们的蚊子传播能力的数据。这将使英国处于更有利的地位，以有效地管理疫情，如果疫情在未来几年发生。一些数据还将为其他蚊媒病毒威胁提供信息。正如北方欧洲的蓝舌病、世界各地的西尼罗河病毒和南美洲的寨卡病毒所证明的那样，虫媒病毒的威胁可能突然出现并迅速传播。如果要有效地控制这种疾病的爆发，并尽量减少对人类和动物种群的影响，就需要事先进行基础研究。

Usutu virus infects and causes large scale mortality in certain species of wild bird (such as blackbird and crows); but in recent years it has been recognised as zoonotic, infecting people, and causing fever and, in some cases, neuro-invasive disease such as encephalitis and meningoencephalitis.Usutu virus is spread by mosquitoes and is emerging throughout Europe. During the warm summer of 2020, zoonotic mosquito-borne Usutu virus was detected in two species of wild birds in Greater London. Furthermore, Usutu virus was detected over a long time period and in the non-migrating house sparrow, strongly suggesting that the virus has established in the UK and local British mosquitoes are transmitting it.The primary mosquito vector of Usutu virus in Europe, the Northern House mosquito, is present in the UK where it feeds predominantly on birds. Recent studies have shown that a laboratory colony of this species is competent to transmit the virus at warm temperatures. Therefore, our native mosquitoes may therefore be capable of transmitting it. In addition, other species of mosquito present in the UK feed on both birds and humans and may therefore be capable of spreading the virus from the bird reservoir to humans. The ability of these species to transmit Usutu virus in the wild is not known.The overall aim of this proposal is to assess the risk to the UK of local and invasive mosquitoes transmitting Usutu virus to birds and humans, at realistic UK temperatures. Using these results, we will then mathematically model the suitability of the UK climate, in conjunction with data on the geographical range of local mosquitoes and reservoir bird species. This will yield risk maps, showing where and when Usutu virus is capable of being transmitted in the UK.At the end of this project, we will have collected extensive data on Usutu virus and the ability of our mosquitoes to transmit it. This will put the UK in a stronger position to effectively manage an outbreak, should one occur in the next few years. Some of the data will also inform on other mosquito-borne viral threats. As demonstrated by bluetongue in northern Europe, West Nile across the world, and Zika in South America, arboviral threats can appear suddenly and spread quickly. Basic research in advance is needed if such outbreaks are to be effectively contained with minimal impact on human and animal populations.