The Black Death is believed to have been the result of plague, an infectious fever caused by the bacterium Yersinia pestis. The disease was likely transmitted from rodents to humans by the bite of infected fleas.The disease dates back to the Middle Ages, when it killed millions in a Europe, before the age of antibiotics. At the time, they did not realize the plague was carried by the fleas who lived on rats. Although the idea of the plague sounds dire, another "black death" is not coming.
