This world map shows the origins and spreading paths of Malaria, Leprosy and Small Pox. No legend, but the implication is that as the main arteries diminish in width down to small capillaries represents the number of infection cases.  Key dates and locations are also identified with event description.

There is no designer byline on the graphic, but map is credited to Haisam Hussein.  I don't see the map in the gallery on Haisam's website, but he is given credit for the map on Lapham's Quarterly.

Found on digg.com.