The dreaded Bubonic Plague that decimated European during the mid-1300s appeared to have first afflicted people thousands of years earlier.
Danish researchers analyzing fossilized teeth of Bronze Age humans have discovered evidence of the plague 4,800 years ago, thousands of years before the disease wiped out between 50 to 60 percent of Europe’s population.
But the bacterium that caused the so-called Black Death was not nearly as aggressive during the Bronze Age, according to the study's lead author, Dr. Simon Rasmussen of Denmark’s Technical University.
He helped analyze 101 fossilized teeth of individuals who lived in a region stretching from what is now central Europe to the border between Russia and Outer Mongolia during the Bronze Age, which lasted from about 3000 BC to 1500 BC.
Only seven of the teeth — from skulls dating between 2,800 BC and 900 BC — contained evidence of the plague, suggesting the bacterium at that point did not spread as easily as it did later. Today, even infected fleas can transmit the disease to humans.
“The plague in the Bronze Age is missing the gene that makes it able to survive inside the flea," said Rasmussen. "So what we think is the plague could not actually be transmitted by fleas back then.”
In a highly publicized paper a few months back, the Danish researchers reported on genomic studies suggesting the plague may have contributed to widespread disease that led to the decline of Classical Greece and weakened the ancient Roman army. Rasmussen says the epidemics may also have led to a number of ancient mass migrations.
“Still today, and also in the Middle Ages, if there were some kind of disease onset, then people would try to flee from it to not be affected by this disease," he said, explaining that migrants carried the disease with them to new settlements.
Plague remains a rare infection in today's world, most recently striking India in 1994, when almost 700 cases were reported to the World Health Organization.
With swift antibiotic treatment, Rasmussen says the plague is almost completely curable.
The latest findings are published in the journal Cell.