About 200 million people today have schistosomiasis, a serious chronic illness caused by a parasitic infection. A big part of why the disease runs rampant today is how our ancestors practiced irrigation...and it's a mistake 1500 years in the making.
The schistosomiasis parasite is generally carried by a type of freshwater snail. Irrigation can cause the snail population to increase and many more people to come into contact with the disease, which is particularly prevalent in Africa, Asia, and South America. Although schistosomiasis doesn't generally kill people, it can damage people's organs and cause developmental problems in children. It's generally considered to be one of the most socioeconomically devastating diseases, trailing only malaria.
But the prevalence of the disease isn't just a result of modern engineering errors. According to new research by Emory anthropologist Amber Campbell Hibbs, ancient mummies from the Nubia region of what is now Sudan tell a compelling story of how schistosomiasis first began to spread.
She studied two groups of mummies - the Kulubnarti population from 1200 years ago, who are not thought to have practiced irrigation, and the Wadi Halfa of 1500 years ago, which the archaeological record shows did indeed use irrigation. The evidence was compelling: 25 percent of the irrigation-using Wadi Halfa mummies carried the schistosomiasis parasite, whereas just 9 percent of the Kulubnarti did.
Campbell Hibbs explains that this doesn't just help us understand the history of the disease - it's also a reminder of how much control over the environment ancient peoples really had, even if that wasn't always a good thing:
"Often in the case of prehistoric populations, we tend to assume that they were at the mercy of the environment, and that their circumstances were a given. Our study suggests that, just like people today, these ancient individuals were capable of altering the environment in ways that impacted their health. We hope that understanding the impact of schistosomiasis in the past may help in finding ways to control what is one of the most prevalent parasitic diseases in the world today. Previously, it was generally assumed that in ancient populations schistosomiasis was primarily caused by S. haematobium, and that S. mansoni didn't become prevalent until Europeans appeared on the scene and introduced intensive irrigation schemes. That's a sort of Euro-centric view of what's going on in Africa, assuming that more advanced technology is needed to control the elements, and that irrigation conducted in a more traditional way doesn't have a big influence on the environment."
In fact, the Nubians were probably healthier than most other groups dealing with the disease, no matter what time or place. That's because they were getting regular doses of tetracycline, which can help mitigate the effects of the disease. And according to Campbell Hibbs's research partner George Armelagos, they probably got that from the beer they brewed. So let that be a lesson to you - when in doubt, beer will probably solve everything*.
*Not intended to be a factual lesson.