Thursday, January 29, 2009

Pharaohs' Plague

The National Geographic magazine had this running article: Bubonic Plague Traced to Ancient Egypt

Panagiotakopulu came upon clues to the plague's presence in ancient Egypt by accident. She had been looking at fossil insect remains to learn about daily life more than 3,000 years ago.

"People lived close to their domestic animals and to the pests that infected their household," Panagiotakopulu said. "I just started looking at what diseases people might have, what diseases their pigs might have, and what diseases might have been passed from other animals to humans."

The researcher used a fine sieve to strain out remains of insects and small mammals from several sites. Panagiotakopulu, who is conducting similar work on Viking ruins in Greenland, said that looking at insects is a key way to reconstruct the past. "I can learn about how people lived by looking in their homes and at what was living with and on them," she said.

In Egypt Panagiotakopulu combed the workers'-village site in Amarna, where the builders of the tombs of Egyptian kings Tutankhamun and Akhenaton lived. There, the researcher unearthed cat and human fleas—known to be plague carriers in some cases—in and around the workers' homes. That find spurred Panagiotakopulu to believe that the bubonic plague's fleaborne bacteria could also have been lurking in the area, so she went in search of other clues.

Previous excavations along the Nile Delta had turned up Nile rats, an endemic species, dating to the 16th and 17th century B.C. The plague's main carrier flea is thought to be native to the Nile Valley and is known to be a Nile rat parasite.

According to Panagiotakopulu, the Nile provided an ideal spot for rats to carry the plague into urban communities. Around 3500 B.C., people began to build cities next to the Nile. During floods, the habitat of the Nile rat was disturbed, sending the rodent—and its flea and bacterial hitchhikers—into the human domain.

Egyptian writings from a similar time period point to an epidemic disease with symptoms similar to the plague. A 1500 B.C. medical text known as the Ebers Papyrus identifies a disease that "has produced a bubo, and the pus has petrified, the disease has hit."

It's possible that trade spread the disease to black rats, which then carried the bacteria to other sites of plague epidemics. Panagiotakopulu suspects that black rats, endemic to India, arrived in Egypt with sea trade. In Egypt the rats picked up plague-carrying fleas and were later born on ships that sailed across the Mediterranean to southern Europe.

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