creakingcricket
Huck said:
The plague did reach Milan in 1348, but brutal quarantine measures controlled it:
"When the pestilence reached Milan, the occupants of the first three houses it struck were walled up -- sick or not -- and left to die. This horrifyingly harsh measure, ordered by the Archbishop, appeared to succeed to some degree, for Milan suffered less from the plague than any other major Italian city.
Florence -- the thriving, prosperous center of trade and culture -- was particularly hard-hit, by some estimates losing as much as 65,000 residents."
http://historymedren.about.com/od/theblackdeath/ig/Spread-of-the-Black-Death/msItalyBD.htm
Florence as the traditional enemy of Milan:
"Another popular explanation for the Italian Renaissance is the thesis, first advanced by historian Hans Baron, that states that the primary impetus of the early Renaissance was the long-running series of wars between Florence and Milan. By the late fourteenth century, Milan had become a centralized monarchy under the control of the Visconti family. Giangaleazzo Visconti, who ruled the city from 1378 to 1402, was renowned both for his cruelty and for his abilities, and set about building an empire in Northern Italy. He launched a long series of wars, with Milan steadily conquering neighbouring states and defeating the various coalitions led by Florence that sought in vain to halt the advance. This culminated in the 1402 siege of Florence, when it looked as though the city was doomed to fall, before Giangaleazzo suddenly died and his empire collapsed."
http://en.wikipedia.org/wiki/Italian_Renaissance
Enemies are typically blamed for disease -- "the French disease." I speculate that in Milan plague would be the "Florence disease" and associated with the Death card.
cc
... then a lot of others were also Florentians, though possibly had been never in Florence. 
