Piles of bones and historical records tell us the Black Death pandemic wiped out as much as half of the population of Europe during the Middle Ages. But how and what, exactly, caused the grisly
The final bell has rung, according to a new study, and the bubonic plague (which is caused by a bacterium also known as Yersinia pestis) is the winner. What’s more, the authors say the same bacteria caused smaller outbreaks during the next four centuries throughout Europe.
“Our data … ends the debate about the etiology of the Black Death, and unambiguously demonstrates that Y. pestis was the causative agent of the epidemic plague that devastated Europe during the Middle Ages,” the authors wrote in the Oct. 7 issue of PLoS Pathogens.
The bubonic plague makes its first deadly appearance in historical records during the sixth century, and scientists and historians have long eyed it as the culprit of the Black Death that went down from 1347-1353 A.D. as well as other plagues throughout history. But uncertainty in genetic data has produced other suspects, including viral hemorrhagic fever or some yet-to-be-discovered disease.
If left untreated, a bubonic plague infection can kill a person in as little as two days, either by causing lymph nodes to burst and flood the bloodstream or by attacking lung tissue to cause an pneumonia. Most often, the disease spreads via fleas that are carried around by rodents. In either case, the bacteria’s genetic signatures can be found in bones long after a victim dies.
To build their case, the study’s authors extracted DNA from more than 75 skeletons in mass graves or plague pits across Europe. As an added measure, the scientists compared the samples to bones in nearby regions unaffected by the disease. All of this data, according to the study, points to bubonic plague as the cause of the 400-year-long pandemic and not other diseases.
Images: 1) Flickr, 2) Sites where scientists collected DNA from bones (green dots) and two possible paths the bubonic plague of 1347 A.D. entered Europe (black, red dotted arrows). PLoS Pathogens
Citation: Haensch, S. et al. “Distinct Clones of Yersinia pestis Caused the Black Death.” PLoS Pathogens. October 7, 2010.
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Authors: Dave Mosher