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.

诸多新兴传染病均为来自动物储存宿主（animal reservoir）的RNA病毒跨种溢出事件。精准识别病毒储存宿主，是预测传染病风险地理分布范围的必要前提，但现有研究极少将储存宿主的分类层级细化至动物物种以下；且仅在特定自然条件与研究方法的支撑下，才能将病毒与宿主的内在关联，与单纯的地理（共）分布隔离现象区分开来。我们在坦桑尼亚境内针对啮齿动物南非硕鼠（Mastomys natalensis）的两个亚分类群接触带开展了系统采样，并完成了详尽的遗传学特征鉴定。我们检出两种截然不同的沙粒病毒（arenavirus）：盖罗病毒（Gairo virus）与莫罗戈罗病毒（Morogoro virus）。二者的空间分布均各自局限于南非硕鼠的一个特定亚群，仅在该接触带的中心区域存在共同检出的情况。该接触带中心区域存在的亚分类群间杂交现象，以及南非硕鼠拥有连续优质的栖息环境，表明两种病毒均具备扩散至对方亚分类群分布范围的生态学可能性，但实际并未发生，这强烈提示存在宿主内在的传播障碍。这类宿主内在的传播障碍，或可解释为何另一种由南非硕鼠携带的沙粒病毒——拉沙病毒（Lassa virus）的人类感染病例仅局限于西非地区。