The disease struck three times during the war, in 430, 429, and 427-6 B.C. By some estimates 100,000 peoplealmost one-third of the Athenian populationdied.
Thucydides, an ancient Greek historian who chronicled the war, contracted the disease and lived to write about it. His is the only known description of the outbreak.
The symptoms of the disease began, Thucydides wrote, with a sudden attack of "violent heats in the head," along with inflammation of the eyes, throat, and tongue, and the emission of fetid breath.
Sneezing, hoarseness, and painful coughing followed. Then came dry retching, spasms, fever, reddish pustules, and ulcers all over the skin.
The University of Athens researchers randomly collected three intact teeth from bodies found in the mass grave at Kerameikos.
The scientists extracted pulp from the teeth and used a technique called polymerase chain reaction to amplify its DNA so that they had enough to work with.
The researchers were then able to match the genetic material to that of Salmonella enterica, the bacteria that causes typhoid fever.
Although his team found that typhoid fever was a cause of the Athens plague, Papagrigorakis acknowledged that it may not have been the only one.
"We have not excluded the possibility of the concurrent existence of another pathogen as well," he said.
Further investigations of the DNA material will be needed to confirm the finding, he said.
Some symptoms mentioned by Thucydides do not coincide with the symptoms of typhoid feverthe acute and sudden onset, for example.
The authors speculate that differences between ancient and present-day Salmonella enterica may partly account for this.
Inaccuracies in Thucydides' description, he said, are also possible. "This is the subject of further investigations, which are already underway," Papagrigorakis said.
The Course of History
In addition to claiming the lives of 100,000 people, the plague caused a great loss of confidence in Pericles.
"A lot of people started to blame Pericles for the plague," said Richard A. Billows, professor of history at Columbia University in New York City.
"'It was your idea that we refuse to submit, it was your idea that we fight the war this way by evacuating people, and now look, we're all dying of the plague,'" he said, imagining what the Athenians may have thought.
After 30 years of war, the Athenians surrendered, and their empire dissolved.
Would the course of history have been altered if there had been no plague?
Pericles himself caught the disease, and although he survived it, he died a year later, probably due to its lingering effects.
"It's likely that if there had been no plague, Pericles would have lived longer," Billows said.
"A lot of upper-class Athenians lived into their 70s and 80s. And [Pericles] was a charismatic and persuasive leader, so with his leadership, the Athenians very likely would have conducted the war differently than they in fact did.
"Whether that would have changed the outcome, it's hard to say."
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