The Black Death arrived in Britain from central Asia in the autumn of 1348, and by late the next spring it had killed 6 out of every 10 people in London. Such a rate of destruction would kill 5 million now. By extracting the DNA of the disease bacterium, Yersinia pestis, from the largest teeth in some of the skulls retrieved from the square, the scientists were able to compare the strain of bubonic plague preserved there with that which was recently responsible for killing 60 people in Madagascar. To their surprise, the 14th-century strain, the cause of the most lethal catastrophe in recorded history, was no more virulent than today’s disease. The DNA codes were an almost perfect match.
According to scientists working at Public Health England (an executive agency of the U.K.’s Department of Health) in Porton Down, southwest England, for any plague to spread at such a pace it must have gotten into the lungs of those victims who were most malnourished and then been spread by coughs and sneezes.
It was therefore a pneumonic plague rather than a bubonic plague — one in which infection is spread from human to human, rather than by rat fleas.
“As an explanation for the Black Death in its own right, it simply isn’t good enough. It cannot spread fast enough from one household to the next to cause the huge number of cases that we saw during the Black Death epidemics,” said Dr. Tim Brooks from Porton Down.
In support of the growing case that this was a fast-acting, direct contagion, archaeologist Dr. Barney Sloane discovered that in the medieval City of London, all wills had to be registered at the Court of Hustings. The documents lead him to believe that 60 percent of Londoners were wiped out.
Today, antibiotics can prevent the disease from becoming pneumonic.
