Knock-on community impacts of a novel vector: spillover of emerging DWV-B from Varroa-infested honeybees to wild bumblebees

Novel transmission routes can directly impact the evolutionary ecology of infectious diseases, with potentially dramatic effect on host populations and knock-on effects on the wider host community. The invasion of Varroa destructor, an ectoparasitic viral vector in Western honeybees, provides a unique opportunity to examine how a novel vector affects disease epidemiology in a host community. This specialist honeybee mite vectors deformed wing virus (DWV), an important re-emerging honeybee pathogen that also infects wild bumblebees. Comparing island honeybee and wild bumblebee populations with and without V. destructor, we show that V. destructor drives DWV prevalence and titre in honeybees and sympatric bumblebees. Viral genotypes are shared across hosts, with the potentially more virulent DWV-B overtaking DWV-A in prevalence in a current epidemic. This demonstrates disease emergence across a host community driven by the acquisition of a specialist novel transmission route in one host, ...新型传播途径可直接影响传染病的进化生态学，对宿主种群产生潜在的显著影响，并对更广范围的宿主群落产生连锁效应。狄斯瓦螨（Varroa destructor）是西方蜜蜂的外寄生性病毒媒介，其入侵为研究新型媒介如何影响宿主群落的疾病流行病学提供了独特契机。这种专性蜜蜂螨可传播变形翼病毒（deformed wing virus, DWV）——一种重要的再暴发蜜蜂病原体，同时也可感染野生熊蜂。通过对比有无狄斯瓦螨的岛屿西方蜜蜂与野生熊蜂种群，我们发现狄斯瓦螨可提升西方蜜蜂以及同域分布熊蜂体内DWV的感染率与病毒滴度。不同宿主间共享病毒基因型，在当前的流行中，潜在致病力更强的DWV-B的感染率已超越DWV-A。该研究证实，单一宿主获得专性新型传播途径可驱动整个宿主群落的疾病暴发……