Catching the plague. New insights into the transmission of teh early modern plague

Guido Alfani, Università Bocconi
Samuel K. Cohn, Glasgow University

It is commonly thought that plague in the past was caused by the same bacillus responsible for the present-day “plague”: Yersinia pestis. This, though, is difficult to spread person to person. As a result, historians and scientists began to question whether Yersinia pestis was the agent of the highly contagious plagues of the past. The authors of this paper have amassed large data sets on Early Modern plagues. Utilizing statistical methods on disease transmission, the data at the authors’ disposal suggest that men and women were transmitting the plague person to person. With family reconstitution methods applied to data from over seven plague waves in Nonantola and Milan, the paper will study plague epidemics and the characteristics of plague mortality. The paper will then comment upon different possibilities: was historical plague Yersinia pestis? Was it an entirely different malady, or a different variant (biovar) of the same malady?