The Fielding H. Garrison Lecture: "Break-Bone" Fever in Philadelphia, 1780: Reflections on the History of Disease.

In the Autumn of 1780 an epidemic hit the city of Philadelphia. The symptoms of the disease resembled those of present day dengue fever, and subsequent observers argued that the disease was in fact dengue. But was it? The question forces us to confront the challenges of retrospective epidemiology and how we examine the history of a disease. This paper examines the 1780 epidemic from two perspectives. First, it looks at evidence that the disease was dengue and examines what this tells us about the epidemic and the conditions that caused it. Second, it looks at the disease from the perspective of Dr. Benjamin Rush, who treated hundreds of patients during the epidemic. In other words, it examines the disease through the lens of eighteenth century medical ideas. The paper concludes that each approach is valuable and reveals different aspects of the relationship between society and disease.