Tuesday, August 30, 2011

Black Death cause identified

A bacterial strain that is now extinct has been identified as the cause of the devastating Black Death plague in the 14th century.

The Black Death is estimated to have killed 30 to 50 million Europeans or about a third of Europe’s population between 1347 to 1351, after spreading there from China and the Middle East, making it one of the worst pandemics in human history.

Now, based on a DNA analysis conducted by researchers at McMaster University in Hamilton, Ont., and the Max Planck Institute in Leipzig, Germany, an international scientific team has concluded the pandemic was caused by a now-extinct strain of Yersinia pestis, the bacterium that causes bubonic plague.

The results were published Monday in an article in the Proceedings of the National Academy of Sciences. The lead authors are Verena Schuenemann at the University of Tubingen in Germany and Kirsten Bos, a graduate student at McMaster University.

While some researchers have always thought Yersinia pestis could be responsible for the Black Death, others had argued that the virulence of the Black Death and the way it spread through populations was so different from the modern bubonic plague that it couldn't be caused by the same bacterium. There are still 2,000 cases of the plague worldwide each year. more