By examining DNA bacteria from medieval plague victims, scientists believe that they have properly identified the bacterium that so readily swept through Europe.
Archaeologists studying the Bubonic Plague in London have determined that the evidence from plague burials and water-front graves suggest that the disease was spread from human to human contact (rather than from flea infested rats).
“The evidence just isn’t there to support it,” said Barney Sloane, author of The Black Death in London. “We ought to be finding great heaps of dead rats in all the waterfront sites but they just aren’t there. And all the evidence I’ve looked at suggests the plague spread too fast for the traditional explanation of transmission by rats and fleas. It has to be person to person – there just isn’t time for the rats to be spreading it.” (Guardian)
Scientists working in China have recently linked climate conditions with outbreaks of the plague bacteria, Yersinia pestis. Plague bacteria is primarily spread by fleas that reside on rodents. During warm, wet months there is more vegetation growth which means an abundance food for rodents. More rodents means more fleas, hence greater spread of plague.
Yersinia pestis is the leading culprit in the Black Death, an epidemic that swept through Europe in the 14th century and ultimately killed 1/3 of the world’s population. The Black Death originated in China and made its way to Europe via traders – most famously when a ship filled with dead or dying men stricken by the plague landed in a Sicilian port in 1347. From there, the plague spread exponentially leaving a swath of death in its wake.
While the plague bacteria still exists today, it is largely controlled and treatable (if detected early). Additionally, better sanitation conditions help to keep the disease at bay. To read more about the new scientific determinations about the connection between weather conditions and the plague, read this article by Discovery News. If you would like to read more about the Chinese origins of the Bubonic Plague, read this article by Discovery News.