The Black Death, the worst plague in Europe's history, killed between 30 million and 50 million people in the 14th century. Now, after analyzing dozens of skeletons, scientists claim to have cracked its genetic code. They say simple antibiotics available today can beat the disease.
According to a study published online in the journal Nature on Wednesday, the 14th century bug, Yersinia pestis, is nearly identical to the modern-day version of the same germ. Its bacterial descendants haven't changed much over 650 years. There are only a few dozen changes among the more than 4 million building blocks of the DNA.
The evolution of society, medicine and human bodies has outpaced that of Y. pestis. This means the Black Death was deadly for reasons beyond its DNA. The circumstances of the world back then made it deadly, say scientists.
The Black Death hit at the worst possible time. The climate was suddenly getting colder, wars and famines had already ravaged populations, and people were moving into closer quarters where the disease could infect them and spread easily, said the study's lead author, Johannes Krause of the University of Tubingen in Germany.
Antibiotics like tetracycline could beat the plague bacteria and the bacteria didn't seem to have the properties that enabled other germs to become drug-resistant, said study co-author Hendrik Poinar of McMaster University in Ontario.
Changes in the treatment of the sick, improved sanitation and economics and better immune system put humanity in a safer position now, Poinar added.