New research suggests that the Black Death, which decimated London's population in the 14th century, was passed from human to human as a pneumonic plague. It was previously believed that the disease was a bubonic plague spread by rats.
A burial site has been uncovered in central London as part of the Crossrail excavation project, and samples from the victims have been analyzed to determine the cause of death. The new theory is that the disease spread to the lungs of sufferers, who then passed it on to others, by coughing. Many victims would have died within 24 hours with the survival rate being much lower than for the bubonic plague. Worldwide, the Black Death is estimated to have claimed 75 million lives.
For the full text of the article in The Telegraph and a video on the burial site discovery by Crossrail engineers, please see http://www.telegraph.co.uk/science/science-news/10731180/Bodies-of-Black-Death-victims-give-up-their-secrets.html.
The new research is discussed in the documentary "Secret History: Return of the Black Death," which will air on Channel 4 in the UK on April 6, 2014, at 8 p.m.