Parasite found in 6,200-year-old grave

Proof that even the earliest agricultural irrigation systems contributed to disease burden may lie in the discovery of a schistosomiasis parasite egg in a 6,200-year-old Syrian grave, it is revealed today.

Schistosomiasis is a disease caused by flatworm parasites that live in the blood vessels of the bladder and intestines.

The oldest schistosomiasis egg found previously was in Egyptian mummies from 5,200 years ago but new research by an international team of archaeologists and biological anthropologists shows it may have been spread by the introduction of crop irrigation in ancient Mesopotamia a 1,000 years earlier.

Their claim, published in The Lancet Infectious Diseases comes after the egg was found in the grave at Tell Zeidan in Syria, the region along the Tigris-Euphrates river system that covers parts of modern-day Iraq, Iran, Kuwait, Syria, and Turkey.

The egg was found in the pelvic area of the burial where the intestines and bladder would have been. Control soil samples from the head and foot areas of the grave contained no parasitic eggs, suggesting that the gravesite was not later contaminated with the parasite.

Dr Piers Mitchell, of the University of Cambridge, UK, who worked with colleagues at The Cyprus Institute and the University of Chicago’s Oriental Institute, said the finding might be among the oldest evidence of man-made technology inadvertently causing disease outbreaks.

“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,” he said.

“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.”

Mitchell P et al. Prehistoric schistosomiasis parasite found in the Middle East. The Lancet Infectious Diseases. 20 June 2014. http://dx.doi.org/10.1016/S1473­3099(14)70794­7 [abstract]