William Johnston, the John E. Andrus Professor of History, is a historian who studies disease and medicine, with expertise in epidemics of infectious diseases. In this Q&A, Johnston discusses the novel coronavirus outbreak and what can be learned from the past. Q: How and when did you start studying the history of disease and medicine? A: About 30 years ago, I wrote my dissertation on the subject, which became my first book, The Modern Epidemic: A History of Tuberculosis in Japan. Around that time, people were starting to consider epidemics of infectious diseases a thing of the past that were…