Data from: When viruses don’t go viral: the importance of host phylogeographic structure in the spatial spread of arenaviruses

Many emerging infections are RNA virus spillovers from animal reservoirs. Reservoir identification is necessary for predicting the geographic extent of infection risk, but rarely are taxonomic levels below the animal species considered as reservoir, and only key circumstances in nature and methodology allow intrinsic virus-host associations to be distinguished from simple geographic (co-)isolation. We sampled and genetically characterized in detail a contact zone of two subtaxa of the rodent Mastomys natalensis in Tanzania. We find two distinct arenaviruses, Gairo and Morogoro virus, each spatially confined to a single M. natalensis subtaxon, only co-occurring at the contact zone’s centre. Inter-subtaxon hybridization at this centre and a continuum of quality habitat for M. natalensis show that both viruses have the ecological opportunity to spread into the other substaxon’s range, but do not, strongly suggesting host-intrinsic barriers. Such barriers could explain why human cases of another M. natalensis-borne arenavirus, Lassa virus, are limited to West Africa.诸多新发传染病均为来自动物宿主的RNA病毒跨种溢出事件。确定宿主种群对于预测感染风险的地理分布范围至关重要，但目前极少有研究将动物物种以下的分类学层级纳入宿主考量范畴，唯有结合关键自然条件与研究方法，方能将病毒与宿主的内在关联与单纯的地理共分布现象区分开来。我们对坦桑尼亚境内两个亚类群的 Natal 多乳鼠（Mastomys natalensis）的接触带进行了采样，并开展了详细的遗传学特征分析。研究发现两种截然不同的沙粒病毒：盖罗病毒（Gairo virus）与莫罗戈罗病毒（Morogoro virus），二者分别仅分布于对应的 Natal 多乳鼠亚类群范围内，仅在接触带的中部区域存在共分布现象。该区域内存在亚类群间的杂交现象，且 Natal 多乳鼠的适宜栖息地呈连续分布，这表明两种病毒均具备向对方亚类群分布范围扩散的生态学条件，但实际并未发生扩散，这强烈提示存在宿主内在的传播障碍。这类宿主内在障碍或可解释为何另一种由 Natal 多乳鼠携带的沙粒病毒——拉沙病毒（Lassa virus）的人类感染病例仅局限于西非地区。