An olden burial site called Tell Zeidan in northern Syria was holding for thousands of years what could be the earliest evidence of human parasitic infection: the egg of a parasite that was found close to the pelvis of a buried child who lived some 6,200 years ago in one of the ancient farming communities.
The scientists who discovered the evidence reveal that the egg dates back to the time when early communities made use of irrigation techniques in growing their crops, which only means that people then spent much time walking in warm water that is an ideal condition for parasites to attach to human skins. Such agricultural irrigation conditions may have initiated the epidemics of a water-born flatworm disease dubbed as schistosomiasis and may have contributed to a widespread of other related diseases.
"We found the earliest evidence for a parasite [that causes] Schistosomiasis in humans," study co-author Dr. Piers Mitchell says to Live Science. Mitchell is also biological anthropologist at the University of Cambridge in England.
Otherwise known as Katayama fever, snail fever or bilharzia, schistosomiasis is triggered by flatworm parasites living in the blood vessels of intestines and bladder. This can bring about bladder cancer, kidney failure and anemia.
Further research also shows that the oldest of such type of egg was found in Egyptian mummies some 5,200 years back. The recent evidence, meanwhile, was from the Fertile Crescent region, which is around the Euphrates and Tigris Rivers in Middle East. The Middle East is said to have several of the first systems invented in irrigation around 7,500 years back.
“The invention of irrigation was a major technological breakthrough (but) it had unintended consequences,” one of the study authors Gil Stein tells The Washington Post in an email.
Stein, who is a Near Eastern archaeology professor at University of Chicago, adds that with more dependable food supply, more diseases came along.
Other experts, meanwhile, issue a word of caution regarding drawing conclusions based on single and initial evidence.
“A single egg simply tells us that the particular person was infected with schistosomiasis; so, drawing any major conclusions regarding route of infection is difficult. It could have been through irrigation, it could have been through natural water ways, it may have even been an infection picked up from travelling elsewhere in the Middle East or North Africa,” Scott Lawton, a parasitologist at the Kingston University London, explains to Science Mag. “There is certainly more work to be done to disentangle the causes of infection in the Syrian gravesite.”
The World Health Organization says schistosomiasis continues to affect nearly 240 million people around the world, and over 700 million people live in areas where it is prevalent.
The study, New diagnostics reform infectious parasite epidemiology, was first published in the online edition of The Lancet Infectious Disease journal on March 19, 2014 and in print on June 2014. The team of biological anthropologists and archaeologists who conducted the study is working at the Oriental Institute at University of Chicago in the U.S., The Cyprus Institute in Cyprus and University of Cambridge.
