Ancient jerash Reveals Millennia-Long history of Plague, Reshaping Pandemic Understanding
Recent research led by the University of south Florida (USF) and Florida Atlantic University (FAU) has yielded groundbreaking insights into the origins and evolution of Yersinia pestis, the bacterium responsible for plague. A study of remains from Jerash, a once-thriving city in the Eastern Roman Empire, revealed evidence of a plague outbreak dating back approximately 1,500 years, offering a crucial window into the disease’s long history.
Jerash, known as a meaningful trade hub with impressive architecture, became a mass burial site during this emergency, indicating the overwhelming impact of the outbreak on urban populations. Analysis of ancient Y. pestis genomes recovered from Jerash, alongside hundreds of other ancient and modern samples, demonstrated that the bacteria circulated among human populations for millennia before the well-known Justinianic Plague outbreak.
This discovery challenges previous assumptions about plague’s origins. researchers found that subsequent plague pandemics, including the devastating Black Death in the 14th century and contemporary cases, did not originate from a single ancestral strain. Instead, they repeatedly emerged from established animal reservoirs in multiple waves across different regions and time periods. This pattern contrasts sharply with the SARS-CoV-2 virus (COVID-19), which stemmed from a single spillover event and spread primarily through human-to-human transmission.
The findings underscore that pandemics are not isolated events, but recurring biological phenomena driven by factors like human congregation, mobility, and environmental change. The research team, acknowledging the personal resonance of studying ancient disease during a modern pandemic, emphasizes the importance of understanding our shared history and utilizing science to recover and share the stories of those affected.
The study highlights the enduring connection between connectivity and pandemic risk, and the difficulty of fully eradicating certain pathogens. As stated by researchers, plague has been a persistent threat for thousands of years, and despite containment efforts, continues to evolve and cause illness today.
Building on the Jerash discovery, the team is now focusing its research on Venice, Italy, and the Lazaretto Vecchio, a historical quarantine island and significant plague burial site. Over 1,200 samples from the Black Death era are currently housed at USF, providing a unique possibility to investigate the interplay between early public health interventions, pathogen evolution, urban vulnerability, and cultural memory.
The research was supported by grants from the USF Provost’s CREATE Award, the USF College of Public Health Research Award, and the USF Microbiome Institute, alongside international collaborations in archaeology and genomics.
