Maps, [Tom Koch] cogently explains, “make arguments about disease, their pattern of incidence, and their method of diffusion. They are workbenches on which we craft our theories about the things that cause health to fail, imaging data collected in this or that disease outbreak. They are not, as some might argue, either mere representations of the world or simple illustrations of work completed in other media.”

During the great plague epidemics of the Middle Ages, for example, maps played a key role in the public health responses of the day including the quarantine. With the realization that the path of the Black Plague pandemic of 1347-1348 was identical to the human network of trade, the ruling government of Venice developed a way to impede that spread by halting the movement of goods and people into its port for a period of forty days, hence quarantine or quarantenaria. During the seventeenth century, cordon sanitaires were developed across Europe thanks to the practice of disease mapping. Borders of armed guards prevented potentially plague-ridden travelers from entering a specific area and sequestered regions were delineated to house those who were stricken with the disease. And while such an approach may sound terribly antiquated, if not outright cruel, modified versions of these “non-pharmaceutical interventions,” as the U.S. Centers for Disease Control and Prevention now terms them, not only played a major role in attenuating the terrible influenza pandemic of 1918, they also helped save lives during the more recent H1N1 flu pandemic in 2009.

Howard Markel Reviews Tom Koch’s “Disease Maps” | The New Republic. Probably should be some tip of the hat to Steven Johnson’s The Ghost Map even in this review.