Bioarchaeological insights into the last plague of Imola (1630-1632)

The plague of 1630-1632 was one of the deadliest plague epidemics to ever hit Northern Italy, and for many of the affected regions, it was also the last. While accounts on plague during the early 1630s in Florence and Milan are frequent, much less is known about the city of Imola. We analyzed the full skeletal assemblage of four mass graves (n = 133 individuals) at the Lazaretto dell'Osservanza, which date back to the outbreak of 1630-1632 in Imola and evaluated our results by integrating new archival sources. The skeletons showed little evidence of physical trauma and were covered by multiple layers of lime, which is characteristic for epidemic mass mortality sites. We screened 15 teeth for Yersinia pestis aDNA and were able to confirm the presence of plague in Imola via metagenomic analysis. Additionally, we studied a contemporaneous register, in which a friar recorded patient outcomes at the lazaretto during the last year of the epidemic. Our multidisciplinary approach combining historical, osteological and genomic data provided a unique opportunity to reconstruct an in-depth picture of the last plague of Imola through the city's main lazaretto.