ABSTRACT

The emergence of SARS-CoV-2, a coronavirus with suspected bat origins, highlights a critical need for heightened understanding of the mechanisms by which bats maintain potentially zoonotic viruses at the population level and transmit these pathogens across species. We review mechanistic models, which test hypotheses of the transmission dynamics that underpin viral maintenance in bat systems. A search of the literature identified only twenty-five mechanistic models of bat-virus systems published to date, derived from twenty-three original studies. Most models focused on rabies and related lyssaviruses (eleven), followed by Ebola-like filoviruses (seven), Hendra and Nipah-like henipaviruses (five), and coronaviruses (two). The vast majority of studies has modelled bat virus transmission dynamics at the population level, though a few nested within-host models of viral pathogenesis in population-level frameworks, and one study focused on purely within-host dynamics. Population-level studies described bat virus systems from every continent but Antarctica, though most were concentrated in North America and Africa; indeed, only one simulation model with no associated data was derived from an Asian bat-virus system. In fact, of the twenty-five models identified, only ten population-level models were fitted to data – emphasizing an overall dearth of empirically derived epidemiological inference in bat virus systems. Within the data fitted subset, the vast majority of models were fitted to serological data only, highlighting extensive uncertainty in our understanding of the transmission status of a wild bat. Here, we discuss similarities and differences in the approach and findings of previously published bat virus models and make recommendations for improvement in future work.

摘要

SARS-CoV-2（一种疑似蝙蝠起源的冠状病毒）的出现，凸显了迫切需要加强对蝙蝠在群体水平上维持潜在人畜共患病毒以及跨物种传播这些病原体的机制的了解。我们回顾了机制模型，该模型测试了支持蝙蝠系统中病毒维持的传播动力学假设。对文献的检索仅发现了迄今为止发表的二十五个蝙蝠病毒系统的机械模型，这些模型源自二十三项原始研究。大多数模型集中于狂犬病和相关狂犬病病毒（11 种），其次是埃博拉样丝状病毒（7 种）、亨德拉病毒和尼帕样亨尼帕病毒（5 种）以及冠状病毒（2 种）。绝大多数研究都在群体水平上模拟了蝙蝠病毒的传播动态，尽管有一些研究在群体水平框架中嵌套了病毒发病机制的宿主内模型，而一项研究则专注于纯粹的宿主内动态。人群水平的研究描述了除南极洲以外的每个大陆的蝙蝠病毒系统，尽管大多数集中在北美和非洲；事实上，只有一个没有相关数据的模拟模型来自亚洲蝙蝠病毒系统。事实上，在确定的 25 个模型中，只有 10 个群体水平模型适合数据——这强调了蝙蝠病毒系统中总体缺乏经验得出的流行病学推断。在数据拟合子集中，绝大多数模型仅拟合血清学数据，这凸显了我们对野生蝙蝠传播状态的理解存在广泛的不确定性。在这里，我们讨论了先前发表的蝙蝠病毒模型的方法和结果的异同，并提出了未来工作的改进建议。