Abstract
The idea of "Patient Zero" was originally linked to the 1980s HIV/AIDS epidemic when the public, as well as the health professionals, searched for an easily identifiable source of the infection. In this paper I argue that although the term itself was coined relatively recently it describes a phenomenon which is far older, going all the way back to early modern and possibly even medieval sources.
I also explain that, despite its antiquity, the "Patient Zero" stories were controversial because they were related to the way in which particular applications of medical theory intersected with empirical observations. In order to demonstrate my point I present several cases of epidemics being brought into the community by a single individual, taken from early modern plague treatises written in Italy, Netherlands, and Central Europe.
Then I describe the link between these "Patient Zero" stories and contemporary medical theories. I examine the place this phenomenon had within the Galenic, Fracastorean and other medical frameworks with particular attention being paid to three points.
First, whether the plague was understood as an individual nosological unit or whether it was more an umbrella term for any disease that was both infectious and deadly. Second, I focus on the relationship between the plague and an epidemic.
In other words, did the term "plague" equal "epidemic"? Finally I ask if the plague was believed to be an infectious disease.