Parasite Egg Found in 6,200-Year Old Grave Suggests Ancient Irrigation Systems Spread Disease

Posted on June 20, 2014

Burial site at Chalcolithic cemetery in Syria

The discovery of a schistosomiasis parasite egg in a 6,200-year-old grave suggests ancient irrigation systems may have inadvertently helped spread disease. Schistosomiasis is caused by flatworm parasites and can result in anaemia, kidney failure and bladder cancer. The egg was found in a grave located at a prehistoric town by the Euphrates River in Syria.

Piers Mitchell at Cambridge, one of the study's authors, says the discovery might be among the oldest evidence of man-made technology inadvertently causing disease outbreaks. The finding indicates schistosomiasis may have been spread by the introduction of crop irrigation in ancient Mesopotamia.

The image below shows the schistosome egg recovered from the pelvic sediment of a human individual.

Schistosome egg found at ancient grave site


Mitchell says in a statement, "The individual who contracted the parasite might have done so through the use of irrigation systems that were starting to be introduced in Mesopotamia around 7,500 years ago. The parasite spends part of its life cycle in snails that live in warm fresh water, before leaving the snail to burrow through the skin of people wading or swimming in the water. These irrigation systems distributed water to crops and may have triggered the beginning of the enormous disease burden that schistosomiasis has caused over the past 6,000 years."

A research paper on the finding is published here in The Lancet. The researchers report in The Lancet, "The individual who contracted the parasite at Tell Zeidan around 6000 years ago might have done so by wading in natural freshwater, or in one of the man-made irrigation systems that were starting to be introduced in the Middle East from 7500 BP to improve crop productivity. Domesticated wheat and barley were farmed at Tell Zeidan despite its location in a climate too arid to support those crops, which suggests the use of an irrigation system."

Photo: Gil Stein, Oriental Institute, University of Chicago

Photo: Piers Mitchell