The recent death of a laboratory assistant at the Irkutsk Anti-Plague Research Institute in Siberia has revived questions about the plague's enduring threat. While the cause of the 28-year-old's lung infection remains unconfirmed, the case has drawn international attention, including from US President Donald Trump. But how worried should Europe be? To answer that, German experts point to the continent's long and well-documented history with the disease.
A history far older than the Black Death
Johannes Krause, an archaeogeneticist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, notes that the plague bacterium Yersinia pestis has been present in Central Europe for millennia. "The plague bacterium can be identified via DNA from skeletons dating back to the Neolithic and Bronze Age, including in southern Germany – for example in the Augsburg region," he explains.
The most infamous outbreak, however, remains the Black Death of 1346–1353. "It reached the territory of the Holy Roman Empire from 1348 onwards via Italy and France," Krause says. "According to tradition, Mühldorf am Inn was the first German-speaking town to be affected, on 29 June 1348. The port cities of Lübeck and Hamburg followed in the summer of 1350, probably via sea routes."
Pinpointing the worst-hit city is difficult. "It is not really possible to name a single 'worst' city; the sources are patchy," says Krause. "Chronicles, for example, report around 12,000 deaths in Erfurt in 1350, and Vienna is thought to have lost around a third of its inhabitants. Overall, probably between a third and a half of the population died, with considerable regional variation."
Trade routes and the spread of disease
The plague's spread was closely tied to human mobility. "The spread of the plague was also rooted in long-distance trade links," explains Martin Bauch from the Leibniz Institute for the History and Culture of Eastern Europe (GWZO). "In a sense it was a side-effect of early 'globalisation'."
Krause echoes this: "Pathogens spread along human trade and travel routes – then via the Silk Road and the Black Sea, today by aeroplane." While the Russian case remains unconfirmed, the current geopolitical context adds a layer of complexity. European travel to Siberia is minimal, partly due to sanctions imposed over Russia's full-scale invasion of Ukraine. The EU's expanding sanctions have further limited contact.
Lessons from the plague: quarantine and scapegoats
The plague's history offers practical lessons. "Quarantine was invented as a response to the plague," Krause notes. Early, determined measures proved effective, a lesson that resonates with modern pandemic responses.
But the Black Death also had darker social consequences. "Epidemics change societies, up to and including the persecution of minorities," Krause warns. "The pogroms against Jewish women and men in 1348 and 1349 are a sobering warning." Bauch agrees: "What we can see very clearly is society's search for scapegoats: in the context of the Black Death there were pogroms against the Jewish population, and even with coronavirus there were deep social tensions."
Plague today: treatable but not gone
Despite its historical terror, the plague is no longer a major threat. "The plague has not disappeared: it survives in rodent populations and repeatedly causes outbreaks, but today it can be treated very effectively with antibiotics and therefore does not pose a threat to humanity," says Krause.
Still, the disease remains a subject of scientific interest. A recent discovery near Erfurt may offer new insights into the Black Death's mortality. An interdisciplinary team from Leipzig, including Bauch, has identified what could be a plague mass grave. "For the first time we may be able to understand the reasons for the high mortality during the 'Black Death': did it make a major difference that people at the time were repeatedly exposed to periods of malnutrition, also because of climatic fluctuations and cooling processes?" Bauch asks.
Chronicles record that around 12,000 dead were buried in eleven large pits outside Erfurt in 1350. Using sediment cores, researchers reconstructed the medieval landscape and found a pit roughly 10 by 15 metres and 3.5 metres deep, containing human bone fragments dated to the 14th century. Krause notes: "Particularly interesting is the fact that the grave was deliberately searched for and found. Experts point out that there are fewer than ten securely dated mass graves of the Black Death in Europe."
Confirmation requires excavation and DNA analysis. "Whether this is really a plague grave can only be shown by an excavation with DNA analysis," Krause says. "Alternative explanations, such as famines or other disasters, cannot yet be ruled out. If the suspicion is confirmed, the material would make it possible to compare the plague genomes from this region with those from other parts of Europe."
The ongoing Siberian plague case may not pose a direct threat to Europe, but it underscores the importance of vigilance and international cooperation. As the history of the Black Death shows, pathogens do not respect borders – and neither should preparedness.
