CityLab’s Marie Patino looks at some of the maps tracking the spread of the COVID-19 coronavirus and from there pivots to some of the ways we’ve tracked disease outbreaks and epidemics in the past. Examples can be found as far back as the 17th century—long before John Snow’s cholera map, in other words.

Related reading: Tom Koch’s Disease Maps: Epidemics on the Ground (University of Chicago Press, 2011) and Cartographies of Disease (Esri Press, 2nd ed 2016), Sandra Hempel’s Atlas of Disease (White Lion, 2018) and, of course, The Ghost Map by Steven Johnson (2006).