Charles Kenny, senior fellow at the Center for Global Development, begins his history of infectious disease with a two-century old quote from An Essay on the Principle of Population (1798): “Premature death must in some shape or other visit the human race.” Malthus reasoned that the power of population was so superior to the power of the earth to produce subsistence that periodic outbreaks of “misery”—either war, pestilence, or famine—were inevitable. Kenny begins his story circa 1800 on purpose. It was an inflection point in the history of infectious disease. Two hundred years ago half of all people born in the world died before their fifth birthday; today it is one in twenty-five. Life expectancy at birth was below 30 in 1870; now it is above 70. Only recently has our ability to control infectious disease made premature death the exception and not the given that Malthus believed it to be. In chapters 2 and 3, Kenny updates Malthus's story of misery's past by noting that infectious disease actually played a relatively minor role when humans lived in hunting and gathering groups and while they gradually spread from Africa across the globe. It assumed a central role, more important than war and famine combined, only with the rise of farming and “civilization,” when humans and animals began clustering together in villages and cities. The virulence of infectious disease rose dramatically with increased density, social interaction, and trade. With over half the world's population now living in cities, and trade and travel at record levels, our current containment of infectious disease is historically unprecedented. In fact, Kenny believes, these levels of globalization and urbanization cannot exist without this containment.

On this larger frame, Kenny appends specific narratives of major pandemics, strategies of containment, public health innovations, vaccines, and responses to new infections. Chapter 4 tells of the massive die-offs that happened when European explorers with their Eurasian diseases of “civilization” arrived in long isolated regions. Chapter 5 tells of the “exclusion instinct” that people repeatedly exposed to deadly outbreaks developed: treating the infected with disgust and quarantine, and fleeing them when possible. Chapter 6 examines various “cleaning up” attempts: cooking food, reducing bad odors, sequestering excrement. By tracing responses to cholera, a fecal-oral bacterial infection which first appeared as a global pandemic in 1817, Kenny documents the trial and error attempts to reduce contamination in water supplies that finally produced tangible infection control. Chapter 7 examines the similar trial and error process that produced beneficial vaccines. Chapter 8 reports the good news that arrived by the mid-twentieth century with the completion of the first stage of the sanitation and medical revolutions: city living being more healthy than rural, life becoming healthier and longer, families becoming smaller and better educated, and trade and travel making the world more interconnected and prosperous.

The concluding chapters examine the vulnerability of our urban and globalized world to new outbreaks of infection. We have lost tens of millions of lives to HIV/AIDS, and face a continual emergence of new threats: avian influenza, Nipah virus, Hendra virus, Ebola, Marburg fever, Lassa fever, cryptosporidiosis, cyclosporiasis, Zika, and hantavirus. Our response often has been too late and too uncoordinated. We have allowed older foes like tuberculosis and malaria to developed multidrug resistance due to our misuse of antibiotics. Covid-19 is proving just how difficult it is to contain and control an emerging viral threat in a world like ours. Kenny argues that we need consistently good sanitation and health systems throughout the world, and better systems of surveillance, screening, isolation, and research. Our modern world simply cannot exist without it.

全球发展中心的高级研究员查尔斯·肯尼 (Charles Kenny)以一篇关于人口原理的论文中的两百年前引用开始了他的传染病史（1798 年）：“过早死亡必须以某种形式或其他形式降临人类。” 马尔萨斯推断，人口的力量远胜于地球的力量来生产生计，以至于“苦难”——战争、瘟疫或饥荒——的周期性爆发是不可避免的。肯尼有意在 1800 年左右开始他的故事。这是传染病史上的一个转折点。200 年前，世界上出生的人中，有一半在五岁生日前死去；今天是二十五分之一。1870 年出生时的预期寿命低于 30 岁；现在它高于 70。直到最近，我们控制传染病的能力才使过早死亡成为例外，而不是马尔萨斯认为的那样。在第 2 章和第 3 章中，肯尼更新了马尔萨斯的悲惨故事” 过去，当人类生活在狩猎和采集群体中，并逐渐从非洲传播到全球时，传染病实际上发挥了相对较小的作用。只有随着农业和“文明”的兴起，当人类和动物开始聚集在村庄和城市中时，它才发挥了核心作用，比战争和饥荒的总和还要重要。随着人口密度、社会交往和贸易的增加，传染病的毒力急剧上升。现在世界上超过一半的人口居住在城市，贸易和旅行达到创纪录的水平，我们目前对传染病的控制在历史上是前所未有的。事实上，肯尼认为，如果没有这种遏制，全球化和城市化的水平就不可能存在。只有随着农业和“文明”的兴起，人类和动物开始聚集在村庄和城市中。随着人口密度、社会交往和贸易的增加，传染病的毒力急剧上升。现在世界上一半以上的人口居住在城市，贸易和旅行达到创纪录的水平，我们目前对传染病的控制在历史上是前所未有的。事实上，肯尼认为，如果没有这种遏制，全球化和城市化的水平就不可能存在。只有随着农业和“文明”的兴起，人类和动物开始聚集在村庄和城市中。随着人口密度、社会交往和贸易的增加，传染病的毒力急剧上升。现在世界上一半以上的人口居住在城市，贸易和旅行达到创纪录的水平，我们目前对传染病的控制在历史上是前所未有的。事实上，肯尼认为，如果没有这种遏制，全球化和城市化的水平就不可能存在。我们目前对传染病的控制在历史上是前所未有的。事实上，肯尼认为，如果没有这种遏制，全球化和城市化的水平就不可能存在。我们目前对传染病的控制在历史上是前所未有的。事实上，肯尼认为，如果没有这种遏制，全球化和城市化的水平就不可能存在。

在这个更大的框架上，肯尼附加了对重大流行病、遏制策略、公共卫生创新、疫苗和对新感染的反应的具体叙述。第 4 章讲述了当欧洲探险家带着他们的欧亚“文明”病来到长期与世隔绝的地区时发生的大规模死亡事件。第 5 章讲述了人们反复暴露在致命爆发中所形成的“排斥本能”：以厌恶和隔离的方式对待感染者，并在可能的情况下逃离他们。第 6 章探讨了各种“清理”尝试：烹饪食物、减少异味、隔离排泄物。通过追踪对霍乱的反应，霍乱是一种粪口细菌感染，于 1817 年首次作为全球大流行病出现，肯尼记录了为减少供水中的污染而进行的反复试验，最终实现了切实的感染控制。第 7 章检查了生产有益疫苗的类似试错过程。第 8 章报告了 20 世纪中叶随着卫生和医疗革命第一阶段的完成而带来的好消息：城市生活比农村更健康，生活变得更健康更长，家庭变得更小，教育程度更高，以及贸易和旅行使世界更加互联和繁荣。

最后几章考察了我们的城市和全球化世界对新的感染爆发的脆弱性。我们已经因艾滋病毒/艾滋病夺去了数以千万计的生命，并面临着不断出现的新威胁：禽流感、尼帕病毒、亨德拉病毒、埃博拉、马尔堡热、拉沙热、隐孢子虫病、环孢子虫病、寨卡病毒和汉坦病毒。我们的反应往往为时已晚，而且过于不协调。由于我们滥用抗生素，我们已经让像结核病和疟疾这样的老对手产生了多药耐药性。Covid-19 证明了在像我们这样的世界中遏制和控制新出现的病毒威胁是多么困难。肯尼认为，我们需要全世界始终如一的良好卫生和卫生系统，以及更好的监测、筛查、隔离和研究系统。