Black Death bacterial plague that devastated 14th century Europe traced to a lake in Central Asia

Maria Spyrou, a researcher on disease history at the University of Tuebingen in Germany and lead author of a new report on the Black Death, a bacterial plague that killed half of Europe’s population in the 14th century: “We found the Black Death’s source strain, and we even know its exact date — 1338.” (University of Tuebingen)

Scientists in Europe say they’ve pinpointed the origins of the Black Death, a bacterial plague that wiped out half of the continent’s population in the 14th century.

The findings counter other theories that the disease — which caused repeated outbreaks into the early 19th century and also left its mark across the Middle East and North Africa — might first have emerged in China.

Drawing on the work of historian Phil Slavin from the University of Stirling in Scotland, who had suggested the disease’s emergence might be linked to an unusual surge of deaths in a town in Central Asia in 1338-1339, the researchers examined DNA from bodies discovered there. They found genetic fingerprints of the bacterium Yersinia pestis in people who had been buried with tombstones referring to a “pestilence” at the site by Lake Issyk Kul in what’s now Kyrgyzstan.

In an article in the journal Nature, the researchers detail how the genetic fingerprints reveal that the strain that devastated the ancient trading community at Issyk Kul also was the precursor to many others that emerged around the same time.

“We found that the ancient strains from Kyrgyzstan are positioned exactly at the node of this massive diversification event,” said Maria Spyrou, a researcher on disease history at the University of Tuebingen in Germany who was the lead author of the new report. “In other words, we found the Black Death’s source strain, and we even know its exact date — 1338.”

The disease, which is spread by rats and their fleas, is known to have eventually made it to the Sicilian port of Messina, carried on trade ships arriving from the Black Sea in 1347.

Sharon DeWitte, a biological anthropologist at the University of South Carolina who wasn’t involved in the study, said it was exciting to have the DNA evidence to back up the previous theory that the disease emerged in Central Asia.

“This study is important because the very precisely dated burials allow for a direct study of the strain as it existed at the time of the initial emergence of the Black Death,” DeWitte said.

The researchers acknowledged that it’s theoretically possible for the bacterium to have originated elsewhere and spread to Central Asia without changing significantly, but the evidence suggested that this was unlikely, DeWitte said.