Very Short Introductions: Brilliant, Sharp, Inspiring Infectious disease is a moving target: new diseases emerge every year, old diseases evolve into new forms, and ecological and socioeconomic upheavals change the transmission pathways that spread disease. But where does disease come from? How is it transmitted from one person to another? And why are some individuals more susceptible than others? In this Very Short Introduction, Marta Wayne and Benjamin Bolker address these questions through the lenses of ecology and evolution. Assessing the management of outbreaks of diseases such as influenza, HIV/AIDS, cholera, and COVID-19, they provide specific examples to illustrate why major diseases still threaten populations all over the world. ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost every subject area. These pocket-sized books are the perfect way to get ahead in a new subject quickly. Our expert authors combine facts, analysis, perspective, new ideas, and enthusiasm to make interesting and challenging topics highly readable. 1. Introduction 2. Transmission at different scales 3. Influenza 4. HIV/AIDS 5. Cholera 6. Malaria 7. Amphibian chytrid fungus 8. SARS-CoV-2/COVID-19 9. Looking ahead Marta L. Wayne is an evolutionary geneticist at the University of Florida. She has studied virus evolutionary ecology in the fruit fly Drosophila melanogaster, a model system for disease in both humans and mosquitoes. Benjamin M. Bolker is a theoretical ecologist at McMaster University in Hamilton, Ontario. He has studied the dynamics of disease in organisms as diverse as humans, red grouse, gopher tortoises, and fruit flies.