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

Usutu病毒在某些种类的野生鸟类(如黑鸟和乌鸦)中感染并导致大规模死亡；但近年来，它被认为是人畜共患病，感染人，并导致发烧，在某些情况下，还会引起脑炎和脑膜炎等神经侵袭性疾病。Usutu病毒通过蚊子传播，正在整个欧洲出现。在2020年温暖的夏天，在大伦敦的两种野生鸟类中检测到了人畜共患蚊媒Usutu病毒。此外，在很长一段时间内，在非迁徙的家雀身上检测到了Usutu病毒，这有力地表明该病毒已经在英国建立，英国当地的蚊子正在传播它。Usutu病毒在欧洲的主要蚊子媒介--北方屋蚊子--存在于英国，在那里它主要以鸟类为食。最近的研究表明，该物种的实验室群体能够在温暖的温度下传播病毒。因此，我们的本土蚊子可能因此有能力传播这种病毒。此外，英国存在的其他种类的蚊子既以鸟类为食，也以人类为食，因此可能能够将病毒从鸟类的储藏室传播给人类。这些物种在野外传播Usutu病毒的能力尚不清楚。这项建议的总体目标是评估在英国现实温度下，本地和入侵蚊子将Usutu病毒传播给鸟类和人类的风险。利用这些结果，我们将结合当地蚊子和水库鸟类的地理范围的数据，对英国气候的适宜性进行数学建模。这将产生风险地图，显示Usutu病毒能够在哪里以及何时在英国传播。在这个项目结束时，我们将收集关于Usutu病毒和我们的蚊子传播它的能力的大量数据。这将使英国在有效管理疫情方面处于更有利的地位，如果在未来几年发生疫情的话。其中一些数据还将告知其他蚊子传播的病毒威胁。正如北欧的蓝舌病、世界各地的西尼罗河病毒和南美洲的寨卡病毒所表明的那样，虫媒病毒威胁可以突然出现并迅速传播。如果要在对人类和动物种群影响最小的情况下有效地控制这种暴发，就需要提前进行基础研究。

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.