Spread of Bubonic Plague, 1347-1351

Not be all-pestilence, all-the-time, but this graph of bubonic plague spread in 14th century Europe is interesting. Notice how it moved in contiguous bands from its starting point in the south to the more northern latitudes over a period of four years.

[via Leonardo Monasterio]

If you were to compare the above to pandemic spread today there would be similarities, of course, but there would also be big differences. Instead of contiguous, banded advance you would see viruses hurled ahead of the index cases by air travel, like spot fires a mile ahead of a Santa Ana-driven wildfire. Instead of bands you would have clusters and jumps, mostly corresponding to airline disease vectors. And instead of four years to travel through a corner of the known world, you would have the virus around the world in four days, as is the case today with this H1N1 swine outbreak.