Mansfield Karen L, Schilling Mirjam, Sanders Christopher, Holding Maya, Johnson Nicholas
Vector Borne Diseases, Virology Department, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey KT15 3NB, UK.
The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK.
Microorganisms. 2024 Jun 27;12(7):1307. doi: 10.3390/microorganisms12071307.
The past three decades have seen an increasing number of emerging arthropod-borne viruses in temperate regions This process is ongoing, driven by human activities such as inter-continental travel, combined with the parallel emergence of invasive arthropods and an underlying change in climate that can increase the risk of virus transmission and persistence. In addition, natural events such as bird migration can introduce viruses to new regions. Despite the apparent regularity of virus emergence, arthropod-borne viruses circulating in temperate regions face the challenge of the late autumn and winter months where the arthropod vector is inactive. Viruses therefore need mechanisms to overwinter or they will fail to establish in temperate zones. Prolonged survival of arthropod-borne viruses within the environment, outside of both vertebrate host and arthropod vector, is not thought to occur and therefore is unlikely to contribute to overwintering in temperate zones. One potential mechanism is continued infection of a vertebrate host. However, infection is generally acute, with the host either dying or producing an effective immune response that rapidly clears the virus. There are few exceptions to this, although prolonged infection associated with orbiviruses such as bluetongue virus occurs in certain mammals, and viraemic vertebrate hosts therefore can, in certain circumstances, provide a route for long-term viral persistence in the absence of active vectors. Alternatively, a virus can persist in the arthropod vector as a mechanism for overwintering. However, this is entirely dependent on the ecology of the vector itself and can be influenced by changes in the climate during the winter months. This review considers the mechanisms for virus overwintering in several key arthropod vectors in temperate areas. We also consider how this will be influenced in a warming climate.
在过去三十年中，温带地区出现的节肢动物传播病毒数量不断增加。这一过程仍在持续，受洲际旅行等人类活动驱动，同时伴随着入侵节肢动物的平行出现以及气候的潜在变化，这些变化会增加病毒传播和持续存在的风险。此外，鸟类迁徙等自然事件也可将病毒引入新的地区。尽管病毒出现似乎有一定规律，但在温带地区传播的节肢动物传播病毒面临着深秋和冬季的挑战，此时节肢动物媒介不活跃。因此，病毒需要越冬机制，否则将无法在温带地区立足。节肢动物传播病毒在脊椎动物宿主和节肢动物媒介之外的环境中的长期存活被认为不会发生，因此不太可能有助于在温带地区越冬。一种潜在机制是持续感染脊椎动物宿主。然而，感染通常是急性的，宿主要么死亡，要么产生有效的免疫反应迅速清除病毒。虽然与蓝舌病毒等环状病毒相关的持续感染在某些哺乳动物中发生，但这种情况很少见，因此在某些情况下，病毒血症的脊椎动物宿主可以在没有活跃媒介的情况下提供病毒长期持续存在的途径。或者，病毒可以在节肢动物媒介中持续存在作为越冬机制。然而，这完全取决于媒介本身的生态学，并且可能受到冬季气候的影响。本综述考虑了温带地区几种关键节肢动物媒介中病毒越冬的机制。我们还考虑了在气候变暖的情况下这将如何受到影响。
