University of Tartu study reveals plague persisted in Europe for 400 years

An international research team led by the University of Tartu has published a study in PNAS revealing that the plague continued to affect Europe for nearly 400 years after the initial Black Death of the mid-14th century. By reconstructing the genomes of the bacterium Yersinia pestis, scientists have mapped how the pathogen evolved and spread through various regions until the 18th century.

The study analyzed 26 reconstructed genomes from 11 archaeological sites across Estonia, Russia, England, the Netherlands, and Switzerland. By combining genetic data with radiocarbon dating, historical records, and local death tolls, researchers were able to refine the dating for 75 total plague genomes.

A key finding is the significant diversification of genetic lineages between 1450 and 1500. Researchers suggest this period may have seen the formation of new animal host reservoirs, allowing the bacteria to persist in nature and resurface in human populations. The spread of the disease was likely influenced by environmental changes, such as droughts, and large-scale population movements.