JERASH, JORDAN—The world’s first pandemic, known as the Plague of Justinian after the sitting Byzantine emperor, killed an estimated 25 to 100 million people between a.d. 541 and 750. Scientists have long speculated about what caused the outbreak and where it originated, though historical sources from the period suggest that it may have begun around Pelusium, Egypt, before spreading rapidly throughout the Middle East and the Mediterranean world. According to a statement released by the University of South Florida (USF), researchers participated in an interdisciplinary study that has uncovered—for the first time—direct genomic evidence pinpointing the bacterium Yersinia pestis as the cause of the plague. The team sequenced genetic material from eight human teeth taken from individuals buried in a mid-sixth to early seventh-century a.d. mass grave beneath the former Roman hippodrome in Jerash, Jordan, a city just 200 miles from ancient Pelusium. The study determined that the plague victims carried nearly identical strains of Y. pestis, confirming for the first time that the microbe was present within the Byzantine Empire between a.d. 550 and 660. “For centuries, we’ve relied on written accounts describing a devastating disease, but lacked any hard biological evidence of plague’s presence,” said USF researcher Rays H.Y. Jiang. “Our findings provide the missing piece of that puzzle, offering the first direct genetic window into how this pandemic unfolded at the heart of the empire.” Yersinia pestis was also responsible for causing the infamous Black Death, which may have wiped out as much as 50 percent of Europe’s population in the fourteenth century. Read the original scholarly article about this research in Genes. To read about evidence of a virulent form of the bacterium that circulated as early as 1800 b.c., go to "Bronze Age Plague," one of ARCHAEOLOGY's Top 10 Discoveries of 2018.
