17 08 11 - 21:57So about that great plague:
Sloane believes there was little difference in mortality rates between rich and poor, because they lived so closely packed together. The plague, he is convinced, spread from person to person in the crowded city.
Mortality continued to rise throughout the bitterly cold winter, when fleas could not have survived, and there is no evidence of enough rats.
Black rat skeletons have been found at 14th-century sites, but not in high enough numbers to make them the plague carriers, he said. - The Guardian
Looks like it was our greed in living so close together that did it, and nothing more.
Now we are packing people in even closer. Woe to us if nature finds a way around our defenses.