Author(s): Kenneth L. Gage
Publication: Advances in Yersinia Research
Publication Date: 2012
Introduction: Plague is an exceptionally virulent flea-borne illness caused by the gram-negative bacterium Yersinia pestis (Prentice and Rahalison 2007 ). Humans are accidental hosts of this bacterium, which normally circulates among certain rodent species and their fleas, occasionally causing widespread plague epizootics with high mortality among its hosts. Most people have little knowledge of plague’s status in the modern world, although many are aware that the disease causes outbreaks with high mortality and can spread very quickly within human populations. Some also remember that plague was the cause of the Black Death, an explosive epidemic that killed perhaps one-third of Europe’s population over an approximately 4 years period in the mid-fourteenth century (Carniel 2008 ) . Although the Black Death is the most widely recognized pandemic, plague also caused two other less well-known pandemics (Justinian’s Plague and the Modern Pandemic) that killed millions, as well as innumerable regional epidemics, some of which caused the deaths of tens of thousands. In addition to causing high mortality, these outbreaks were characterized by the explosive spread of plague among its victims.