[James C. Bennett]

I understand, but distribution doesn’t mean Europeans are in physical contact with black rats like they once were when the plagues raged.

http://acsonline.org/wp-content/uploads/2011/11/BlueWhaleRangeMap-xsm.gif

Going by the distribution map of blue whales, you’d be led to believe they are teeming in numbers, in all the Earth’s oceans. They aren’t.

[muawiyah]

That's why rats carry fleas! Remember, this is a multi-host disease. Rats to fleas to humans to humans to humans ~ and it takes several forms depending on how its transmitted.

Europe hasn't had a really good black plague since they got control of their rats ~ but that could disappear in a year with a bumper crop of rats.