In Garrett’s use of the term, amplifiers are sets of circumstances that enable infectious diseases to rise far more rapidly than they would otherwise. Among the amplifiers she highlights are the emergence of new social norms in sexual practice (specifically, multiple-partner sex), the reuse of syringes in medical and drug-use contexts, medical environments that promote drug resistance, and air-recirculation technology.

“Disease cowboys” is a phrase Garrett uses to designate a class of doctors active from the 1950s to the 1980s who did fieldwork around the world and often undertook great personal risks to stem the rising tide of new infectious outbreaks. This includes many of the leading players in the stories of The Coming Plague, such as Karl Johnson, Joe McCormick, Daniel Tarantola, and Peter Piot. In Garrett’s view, their on-site research gave them a broad understanding of multiple fields of disease management—from ecology to immunology to tropical disease—that was not available through the conventional, highly-specialized medical training common in the US. With the passing of the disease cowboys’ generation, other medical professionals have lost a robust and holistic view of disease emergence and management.