Black Death wasn't actually bubonic plague, study finds

In this Wednesday, March 26, 2014 photo, one of the skeletons found by construction workers under central London's Charterhouse Square is pictured. (AP Photo/Lefteris Pitarakis)

A fascinating sidebar to the news that some of the skeletons dug up in London during excavation for a train line last year are indeed the remains of Black Death victims: The Observer zeroes in on a new theory as to how the disease spread, and according to researchers, we might want to stop pinning the blame on fleas.

The long-running assumption has been that fleas living on rats spread the strain by biting a sick person then biting a healthy person. But the DNA extracted from the 14th-century skeletons' teeth wasn't any more virulent than a strain that recently hit Madagascar.

That country saw 60 deaths, while 60% of Londoners are believed to have died centuries ago. The Week zeroes in on the nagging question that followed the finding: Why was the earlier strain so much deadlier? Scientists with Public Health England posit that the plague must have been spread in an airborne manner, via coughs and sneezes, in order to travel so pervasively.

If that's indeed true, then the Black Death wasn't a bubonic plague at all, but a pneumonic one. The rat flea "explanation ... simply isn't good enough," explains Public Health England's Tim Brooks, whose theory will air in a UK documentary on Sunday.

"It cannot spread fast enough from one household to the next to cause the huge number of cases that we saw." Other Black Death secrets revealed: A second wave of victims lived during a "period of lawlessness."