The Cartography of Contagion: A Narrative Review of Medical Geography from Snow's Cholera Map to Networked Epidemics

Abstract

Medical geography---the study of where disease occurs and why place matters to health---began with a map: John Snow's 1855 tracing of cholera's deaths to the Broad Street pump, the field's founding demonstration that contagion has an address. This article presents a narrative review of that arc's canonical line: Snow's 1855 On the Mode of Communication of Cholera, May's 1958 The Ecology of Human Disease, Learmonth's 1988 Disease Ecology, Cliff and Haggett's 1988 Atlas of Disease Distributions, Gould's 1993 The Slow Plague, Smallman-Raynor and Cliff's 2004 War Epidemics, Haggett's 2000 The Geographical Structure of Epidemics, Meade and Earickson's 2000 Medical Geography, Mayer's 2000 essay on emerging infections, Ostfeld, Keesing, and Eviner's 2008 Infectious Disease Ecology, Keeling and Rohani's 2008 Modeling Infectious Diseases, and Brockmann and Helbing's 2013 hidden geometry of networked contagion. The review is organized around three themes: origin, in which Snow's mapping established place's causal role; diffusion, in which the waves' and hierarchies' and war's structures of epidemic spread were mapped; and synthesis, in which ecology's, modeling's, and network science's frameworks unified the field. It is concluded that medical geography is epidemiology's spatial conscience---the discipline that remembers every epidemic is also a map---and that its methods now run the world's outbreak responses.