PNAS:预测人类流行性病毒
澳大利亚悉尼大学一项研究发现，识别出预测何种病毒最可能在人类中间传播的生物因素，有可能帮助预防和控制暴发。多数新发感染源于从动物到人的病毒传播，但是没有造成导致一场流行所必需的持续的人与人之间的传播。及早探测到有能力在人类中间有效传播的病毒感染对于大流行规划至关重要。Edward Holmes及其同事编纂并分析了203种人类病毒的一个数据库，并且使用统计模型识别出预测哪种病毒最可能在人群中成功出现的生物因素。人与人之间传播的可能性因为宿主死亡率低和长期慢性感染而增加，这两种情况都能让病毒有更多时间传播。相比之下，人与人之间的传播的可能性因为一个病毒外壳的存在而减少，病毒外壳容易降解而且在环境中不稳定。此外，病媒传播的病毒比非病媒传播的病毒在人类中间传播的可能性更低，这可能是由于适应多个宿主的困难。这组作者说，这些生物因素可能用于预测哪些病毒可能导致流行，让公共卫生官员采取合适的手段预防和控制这些暴发。
原文链接：
Virological factors that increase the transmissibility of emerging human viruses
原文摘要：
The early detection of pathogens with epidemic potential is of major importance to public health. Most emerging infections result in dead-end “spillover” events in which a pathogen is transmitted from an animal reservoir to a human but is unable to achieve the sustained human-to-human transmission necessary for a full-blown epidemic. It is therefore critical to determine why only some virus infections are efficiently transmitted among humans whereas others are not. We sought to determine which biological features best characterized those viruses that have achieved sustained human transmission. Accordingly, we compiled a database of 203 RNA and DNA human viruses and used an information theoretic approach to assess which of a set of key biological variables were the best predictors of human-to-human transmission. The variables analyzed were as follows: taxonomic classification; genome length, type, and segmentation; the presence or absence of an outer envelope; recombination frequency; duration of infection; host mortality; and whether or not a virus exhibits vector-borne transmission. This comparative analysis revealed multiple strong associations. In particular, we determined that viruses with low host mortality, that establish long-term chronic infections, and that are nonsegmented, nonenveloped, and, most importantly, not transmitted by vectors were more likely to be transmissible among humans. In contrast, variables including genome length, genome type, and recombination frequency had little predictive power. In sum, we have identified multiple biological features that seemingly determine the likelihood of interhuman viral transmissibility, in turn enabling general predictions of whether viruses of a particular type will successfully emerge in human populations.
作者：Jemma L. Geoghegan
