Plague's centuries-long European persistence traced through ancient genomes
Researchers reconstructed 26 Yersinia pestis genomes from human remains across five European countries, showing that plague re-emerged from multiple reservoirs rather than a single source. They also developed a method to date ancient plague genomes more precisely, linking many to specific historical outbreaks.
The study's 26 reconstructed genomes span roughly four centuries of European plague activity, drawn from remains at 11 sites across five countries. Genetic evidence indicates the bacterium entered Estonia repeatedly from the late 1300s onward, with previously unknown lineages appearing in both urban and rural contexts. Around 1450–1500, plague lineages expanded dramatically, splitting into three distinct branches that may have seeded new wild rodent reservoirs.
Researchers also linked the Great Renaissance Drought to this expansion, noting that modern plague systems respond strongly to climate shifts affecting rodent host populations. Dating ancient genomes precisely remains difficult—radiocarbon methods often yield windows exceeding a century—so the team developed a new approach to align genetic data with historically documented outbreaks, improving temporal resolution for these centuries-old infections.
This research could reshape how historians and epidemiologists understand disease persistence in premodern Europe. If plague repeatedly re-entered from multiple reservoirs rather than lingering in one location, public health planning for zoonotic diseases may benefit from broader surveillance of wildlife hosts and trade corridors. The improved dating method could also help researchers correlate ancient outbreaks with climate events and historical records, potentially refining models of how environmental factors drive disease emergence across centuries.