Global trade of coronavirus hosts: bringing geographically isolated hosts and viruses together risks novel recombination and spillover to humans

新型致病性冠状病毒——如SARS-CoV，可能还有SARS-CoV-2——是由两种冠状病毒在单个宿主细胞中共同感染其他病毒，然后“交换”它们的部分基因组而产生的。这种交换（称为同源重组）的结果是一种新的子病毒，它含有每个亲本病毒的成分。这些病毒随后在宿主动物种群中传播，然后扩散到人类。我们之前的工作已经确定了对每种冠状病毒敏感的哺乳动物和鸟类宿主以及对多种冠状病毒株（重组宿主）具有生物学敏感性的宿主。在这里，我们将使用一种新的生态网络方法，整合宿主物种的存在、栖息地和行为，表明宿主物种的生态特征，我们将在之前的工作基础上预测接触促进的冠状病毒共享。将这些预测与流行病学相关的空间预测因子相结合，将使我们能够预测冠状病毒重组的地理热点（工作包1），从而能够开展有针对性的空间监测和缓解工作。许多冠状病毒宿主与人类相互作用（例如通过地理/栖息地重叠），或被人类用作（例如宠物/食物）。通过利用开放获取来源的宿主物种利用数据丰富WP1的新网络，我们将估计先前确定的宿主的原位溢出可能性（工作包2）。强调减轻溢出效应工作的优先物种和地理热点。野生动物贸易与包括SARS-CoV-2在内的冠状病毒对人类的溢出有关。贸易也可以很容易地促进在地理上隔离的宿主及其各自的冠状病毒之间的同源重组。在我们的预测框架中利用全球动物贸易及其使用将使我们能够评估贸易对外溢和重组风险的影响（工作包3）。了解野生宿主贸易的相对风险将有助于深入了解可避免的人类对新型冠状病毒产生的影响。

Novel pathogenic coronaviruses - such as SARS-CoV and probably SARS-CoV-2 - arise by two coronaviruses co-infecting viruses a single host cell, and then 'swapping' parts of their genome. The result of this swapping (termed homologous recombination) is a novel daughter virus containing components of each parent virus. These viruses then circulate in reservoir animal populations before spillover to humans.Our previous work has identified mammalian and avian hosts susceptible to each coronavirus and hosts biologically susceptible to multiple coronavirus strains (recombination hosts).Here, using a novel ecological network approach, integrating presence, habitat, and behaviour indicating ecological traits of host species, we will build on our previous work to predict contact facilitated sharing of coronaviruses. Combining these predictions with epidemiologically-relevant spatial predictors, will allow us to predict geographical hotspots of coronavirus recombination (Work package 1), and therefore enable specific spatially-targeted surveillance and mitigation efforts.Many coronavirus hosts interact with humans (e.g. through geographic/habitat overlap), or are used by humans as (e.g. pets/food). By enriching our novel network from WP1 with host species utilisation data from open-access sources, we will estimate the in situ likelihood of spillover from our previously identified hosts (Work package 2). Highlighting priority species and geographic hotspots for spillover mitigation efforts.Wild animal trade has been implicated in the spillover of coronaviruses, including SARS-CoV-2, to humans. Trade could also readily facilitate homologous recombination in otherwise geographically isolated hosts and their respective coronaviruses. Utilising global animal trade and usages in our predictive framework will enable us to assess the impact of trade on spillover and recombination risk (Work package 3). Understanding the relative risk of wild host trade will allow insight into avoidable human influence on novel coronavirus generation.