Black Death: the exact origin of the pandemic identified centuries later

Long before the Covid-19 pandemicthere was that of the plague black, the most important that humanity has ever known. Caused by the bacterium Yersinia pestis, the disease entered Europe around 1347 via, in all likelihood, trade routes from Central Asia. Within seven years, the Black Death killed around 60% of Europe’s population. This first vague which swept between 1346 and 1353 allowed theemergence of a multitude ofepidemics secondary in Europe, the Middle East and North Africa which spread until the end of the XIX^e century.

Going back in time and pinpointing the origin of these 500 years of epidemic remained a real challenge for scientists, until the recent publication in Nature new genomic data which make it possible to locate geographically and temporally the start of the Black Death epidemic. According to this multidisciplinary team ofhistorians and biologists, it began in the mountainous surroundings of Lake Issyk-Kul, located today in Kyrgyzstan, in 1338 precisely.

Archaeological evidence…

This conclusion is based on archaeological evidence and genetic. Indeed, previous research, carried out in 1886, had identified tombs dating from 1338-1339 near Lake Issyk-Kul bearing a specific inscription in Syriac – the language spoken by these local communities – interpreted as meaning “pestilence”. Obviously, a disease claimed many victims in the region a few years before the Black Death arrived in Europe.

This hypothesis, debated for a long time in the scientific community, was opposed to the more popular one, which placed the beginnings of the Black Death in China. ” We were finally able to show that the epidemic mentioned on the tombstones was indeed caused by the plague », assures Phil Slavinhistorian at the University of Stirling.

…and genetics

Added to these archaeological clues is the genetic work carried out by the team from the University of Tübingen and Stirling. Of the’DNA of Yersinia pestiswas isolated from the remains interred in the “pestilential” graves; phylogenetically speaking, this one belongs to strains that emerged before a ” big Bang of genetic diversity. An event that allowed the bacterium to acquire abilities pandemic and that scientists placed between the X^e and the fourteenth^e century. ” We found that the ancient strain of Kyrgyzstan is located exactly at the heart of the massive diversification event. In other words, we have found the strain that caused the Black Death and we even know its exact date. [l’année 1338] “, explains Maria Spyrou, main author of this work.

The nomads of Lake Issyk-Kul probably became contaminated through close contact with animals carrying Yersinia pestis. Indeed, the rodents are the natural reservoir of the plague – humans catch the disease via the bite of fleas that live on infected animals or by contact with another patient. Moreover, even today, the bacterium remains sheltered in the organism of rodents and occasionally causes cases of plague, especially in Mongolia and in China.