Overview

• Researchers identified Yersinia pestis in DNA recovered from eight teeth taken from mass-burial chambers beneath the Roman hippodrome in Jerash, Jordan.
• Sequenced strains were nearly identical and date to AD 550–660, consistent with a rapid, high-mortality outbreak within the Byzantine Empire.
• The hippodrome’s conversion into a mass grave highlights how an urban center was overwhelmed during the First Pandemic.
• A separate analysis of hundreds of ancient and modern genomes finds that pandemic-causing lineages emerged multiple times from deep regional reservoirs rather than from one continuous lineage.
• The team is expanding to Venice’s Lazaretto Vecchio with more than 1,200 Black Death–era samples now housed at USF, as rare contemporary cases underscore that the bacterium persists in animal hosts.