Recent scientific evidence shows the historic bubonic plague originated more than 2,000 years earlier than previously thought. Researchers set up their search for the origin of the bacterium Yersinia pestis, an ancient bacterium responsible for killing millions of people in the second human pandemic or Black Death in Europe from 1347 to 1351, and discovered the microbe’s existence in humans thousands of years earlier.
Scientists took DNA samples from the teeth of 101 European and Asian Bronze Age human skeletal remains and found the Yersinia pestis strain in seven human remains in recovered sites that stretch from Poland to Serbia.
On Thursday, researchers at the University of Copenhagen in Denmark wrote their findings concerning their plague endemic breakthrough and discovery in the journal Cell.
“Our results show that plague infection was endemic in the human populations of Eurasia at least 3,000 years before any historical recordings of pandemics.”
The bacteria Yersinia pestis is the microorganism that caused the plague and other human pandemics with millions of deaths throughout human history. However, how and when the bacterium originated has remained a mystery.
Researchers of this recent study report they discovered the oldest direct evidence of Yersinia pestis. Microbiologists identified the microbe in the ancient DNA of human teeth from Europe and Asia dating from 2,800 to 5,000 years ago. By using a DNA sequencing laboratory, researchers found the origins of the Yersinia pestis lineage to be at least two times older than earlier estimations.
The results of this recent plague study show that the plague infection was endemic in the human populations of Eurasia at least 3,000 years before any historical recordings of pandemics.
The plague, or the pneumonic plague, is caused by the bacteria Yersinia pestis, which is being directly transmitted through human-to-human contact. When the plague is transmitted via fleas, this is referred to as a common vector, a bubonic or septicemic plague.
As of today, three historic human plague pandemics have been documented. The First Pandemic started with the Plague of Justinian (541–544 AD), but continued sporadically until close to 750 AD. Some suspect the Plague of Justinian was responsible for weakening the Byzantine Empire.
The Second Pandemic began with the Black Death in Europe that started from 1347 to 1351 AD. Waves of other plagues followed, such as the Great Plague of 1665–1666 AD, and lasted until the 18th century.
The Black Death alone is estimated to have killed 30 – 50 percent of the European population. Many believe this plague is responsible for an economic and political collapse across Europe.
The Third Pandemic, which emerged in China in the 1850s, erupted into a major epidemic in 1894 before it globally spread. This plague contributed to a series of epidemics until the middle of the 20th century.
According to the authors of this recent study, earlier outbreaks such as the Plague of Athens (430–427 BC) and the Antonine Plague (165–180 AD) may have also occurred; however, there is no direct proof confirming that the Yersinia pestis microbe was responsible for those outbreaks.
It is nearly impossible to know exactly what caused the earlier plague outbreaks. However, the authors of this study suggest the plague epidemics during the Bronze Age may be a contributing factor as to why large groups of people migrated to other geographical areas – far from their indigenous habitats. Earlier ancestors may have been trying to escape from the deadly grip of the fatal disease.
The New York Times reports a comment made by Eske Willerslev, director of the Center for GeoGenetics at the University of Copenhagen and co-author of the study.
“To my mind, this leaves little doubt that this has played a major role in those population replacements.”
For decades, microbiologists and historians have been searching for the origin of the plague.
In a NBC News article, Eske Willerslev added that this recent scientific discovery of Yersinia pestis DNA evidence dating back to the Bronze Age opens doors for new studies involving the progression of diseases.
“This study changes our view of when and how plague influenced human populations and opens new avenues for studying the evolution of diseases.”
The Yersinia pestis microbe still causes plague, and it is still sporadically infecting and killing people. The bacterium has infected 15 people and killed four of them this year in the United States. On a global scale, approximately 1,000 to 2,000 cases of the plague are reported to the World Health Organization every year.
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