Why did plagues stop?
In the early middle ages up to half of the population of Europe were wiped out by the Black Death, caused by the bacterium Yersinia pestis. But, following its arrival, the initial pandemic wave waned and was replaced by a series of localised epidemics around Europe until the 18th Century, when it abruptly disappeared. So how do we account for this behaviour? From the University of Tuebingen, Kirsten Bos explained why to Chris Smith...
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