Scientists have successfully mapped the complete genome of the Black Death - the bubonic plague that wiped out 50 million Europeans between 1347 and 1351.

According to a study published Tuesday, a less virulent version of the 14th century's Black Death plague is still present today.

Black Death, one of the deadliest pandemics in human history, has been confirmed by anthropologists to have been caused by a germ called Yersinia pestis.

Prairie dogs, once abundant in the Rocky Mountains and Great Plains, have been decimated in recent decades by plague – a virulent bacterial disease spread by fleas.

LOUISVILLE, Ky., Oct.