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

乌苏图病毒感染某些野生鸟类（如黑鸟和乌鸦）并造成大规模死亡；但近年来，它被认为是人畜共患疾病，会感染人类，引起发烧，在某些情况下还会引起脑炎和脑膜脑炎等神经侵袭性疾病。乌苏图病毒通过蚊子传播，正在整个欧洲出现。 2020 年温暖的夏季，在大伦敦的两种野鸟中检测到了人畜共患的蚊媒乌苏图病毒。此外，在很长一段时间内在非迁徙麻雀中检测到乌苏图病毒，强烈表明该病毒已在英国定居，并且英国当地的蚊子正在传播该病毒。乌苏图病毒在欧洲的主要蚊媒北方屋蚊存在于英国，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能够传播它。此外，英国存在的其他种类的蚊子以鸟类和人类为食，因此可能能够将病毒从鸟类宿主传播给人类。这些物种在野外传播乌苏图病毒的能力尚不清楚。该提案的总体目标是评估在英国实际温度下，当地和入侵蚊子将乌苏图病毒传播给鸟类和人类对英国的风险。然后，我们将利用这些结果，结合当地蚊子和水库鸟类地理范围的数据，对英国气候的适宜性进行数学建模。这将产生风险地图，显示乌苏图病毒能够在英国传播的地点和时间。在该项目结束时，我们将收集有关乌苏图病毒以及蚊子传播该病毒的能力的大量数据。如果未来几年爆发疫情，这将使英国在有效管理疫情方面处于更有利的地位。一些数据还将提供有关其他蚊媒病毒威胁的信息。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证明的那样，虫媒病毒威胁可能会突然出现并迅速传播。如果要有效遏制此类疫情的爆发，同时将对人类和动物种群的影响降到最低，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.