The current SARS-CoV-2 pandemic is a harsh reminder of the fact that, whether in a single human host or a wave of infection across continents, viral dynamics is often a story about the numbers. In this snapshot, our aim is to provide a one-stop, curated graphical source for the key numbers that help us understand the virus driving our current global crisis. The discussion is framed around two broad themes: 1) the biology of the virus itself and 2) the characteristics of the infection of a single human host. Our one-page summary provides the key numbers pertaining to SARS-CoV-2, based mostly on peer-reviewed literature. The numbers reported in summary format are substantiated by the annotated references below. Readers are urged to remember that much uncertainty remains and knowledge of this pandemic and the virus driving it is rapidly evolving. In the paragraphs below we provide 'back of the envelope' calculations that exemplify the insights that can be gained from knowing some key numbers and using quantitative logic. These calculations serve to improve our intuition through sanity checks, but do not replace detailed epidemiological analysis.

中文翻译：

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SARS-CoV-2（COVID-19）的编号

当前的SARS-CoV-2大流行严重提醒了这样一个事实，无论是在单个人类宿主中还是在各大洲的感染浪潮中，病毒动力学通常都是有关数字的故事。在此快照中，我们的目标是为关键数字提供一站式，精选的图形源，以帮助我们了解导致当前全球危机的病毒。讨论围绕两个广泛的主题进行：1）病毒本身的生物学特性，以及2）单个人类宿主感染的特征。我们的一页摘要提供了与SARS-CoV-2相关的关键数字，这些数字主要基于同行评审的文献。摘要格式报告的数字由以下带注释的参考文献证实。敦促读者记住，仍然存在很多不确定性，并且对这种大流行及其驱动的病毒的知识正在迅速发展。在下面的段落中，我们提供“封底”计算，这些计算例证了通过了解一些关键数字并使用定量逻辑可以获得的见解。这些计算可通过健全性检查来改善我们的直觉，但不能代替详细的流行病学分析。