A sharper picture of a pandemic: Uncovering the complex history of the plague after the Black Death

Key Points:

• Researchers from the University of Tartu analyzed DNA from 26 Yersinia pestis genomes across Europe, revealing that plague recurred in multiple waves from the 14th to 18th centuries rather than persisting in a single location after the Black Death.
• The study identified a major diversification of plague lineages around 1450–1500, possibly linked to climatic changes such as the Great Renaissance Drought, which may have influenced plague reservoirs in wild rodent populations.
• A novel method was developed to more precisely date ancient plague genomes by placing them on the bacterium’s evolutionary tree, enabling researchers to connect genetic data with specific historical outbreaks.
• The research highlights that human activities, including warfare during the Thirty Years' War and the Great Northern War, significantly facilitated plague spread along troop and refugee routes.
• By combining genetics, archaeology, history, and radiocarbon dating, the study provides new insights into the long-term dynamics of plague, offering valuable knowledge for understanding infectious disease persistence and aiding modern public health surveillance.