Last year, we reported on an analysis of soil samples collected from a stone toilet found within the ruins of a swanky villa, revealing the presence of parasitic eggs from four different species. Conclusion: The wealthy, privileged elite of Jerusalem in the seventh century BCE were plagued by poor sanitary conditions and resulting parasitic intestinal diseases. Now scientists have found evidence of a parasite that causes dysentery in soil samples collected from that same stone toilet, as well as a second stone toilet from the same region that is nearly identical in design. The results appear in a new paper published in the journal Parasitology.
"The fact that these parasites were present in sediment from two Iron Age cesspits suggests that dysentery was endemic in the Kingdom of Judah," said co-author Piers Mitchell, an archaeologist at the University of Cambridge. "Dysentery is spread by feces contaminating drinking water or food, and we suspected it could have been a big problem in early cities of the ancient Near East due to overcrowding, heat and flies, and limited water available in the summer."
Archaeologists can learn a great deal by studying the remains of intestinal parasites in ancient feces. For instance, prior studies have compared fecal parasites found in hunter-gatherer and farming communities, thereby revealing dramatic dietary changes, as well as shifts in settlement patterns and social organization coinciding with the rise of agriculture. The domestication of animals, in particular, led to more parasitic infections in farming communities, while hunter-gatherer groups were exposed to fewer parasites and transmissible diseases given their nomadic lifestyle. This is even reflected in modern nomadic communities of hunter-gatherers.
There are references to intestinal parasites in many ancient texts from the Israel region, with the Fertile Crescent likely predating other regions for evidence of intestinal parasitic infection. But there is limited archaeological evidence of toilets in ancient Israel, with the earliest three examples dating back to the late Bronze Age—all located in palatial areas, indicating that toilets were a privilege afforded primarily to members of ruling groups. But there have been only two studies examining possible parasitic remains at any of the toilets found thus far, and only one of them reported the recovery of the eggs of intestinal parasites.
That changed in 2022. A few years earlier, the Israel Antiquity Authority began excavating the ruins of a large estate known as Armon Hanatziv, or the Commissioner's Palace, dating back to the mid-seventh century BCE—i.e., the First Temple period, likely falling between the reigns of King Hezekiah and King Josiah. When the garden was excavated, archaeologists found evidence of a large water reservoir and a cubical limestone object with a hole in the center—likely the remains of a primitive toilet seat.
Dafna Langgut of Tel Aviv University and the Steinhardt Museum of Natural History—a leading researcher in the emerging field of archeoparasitology—and her team collected 15 sediment samples from the cesspit below the stone toilet seat. They chemically extracted the parasite eggs and examined them under a microscope to identify and measure them. Langgut et al. found eggs from four intestinal parasites in six of those samples: whipworm, beef/pork tapeworm, roundworm, and pinworm. It was the earliest record of roundworm and pinworm in ancient Israel.
Mitchell and his fellow co-authors on this latest paper were intrigued by descriptions of diarrhea among the people of what is now the Near and Middle East in texts dating back to Mesopotamia during the first and second millennium BCE. "If a person eats bread and drinks beer and subsequently his stomach is colicky, he has cramps and has a flowing of the bowels, setu has gotten him," one sample passage read. Sometimes there were suggested incantations to speed recovery. "Those early written sources do not provide causes of diarrhea but they encouraged us to apply modern techniques to investigate which pathogens might have been involved," said Mitchell.
They decided to analyze fecal samples collected from sediment underneath two ancient stone toilets located just south of the Old City. One was the toilet at Armon Hanatziv that was the focus of last year's study. The other was of a virtually identical design, positioned above a plastered cesspit. It was found at a site known as the House of Ahiel, a domestic building with seven rooms that likely housed an upper-class family around the 8th century BCE when Jerusalem was the capital of the Kingdom of Judah. The building was destroyed in 586 BCE when Babylonian King Nebuchadnezzar II sacked Jerusalem for the second time, effectively destroying the Kingdom of Judah.
Detecting the kinds of parasites that cause dysentery is a bit more challenging than detecting the eggs of tapeworms or whipworms, because they are so fragile. So Mitchell et al. used a biomolecular method (called ELISA) that binds antibodies onto proteins produced only by the single-celled organisms they were interested in studying. They tested specifically for three different parasitic microorganisms known to commonly cause diarrhea in humans: Entamoeba, Giardia, and Cryptosporidium.
Tests for the first two parasites came up negative; tests for Giardia were positive. Ergo, "We know for sure that Giardia was one of those infections responsible [for outbreaks of diarrhea]," said Mitchell. It's the earliest known evidence yet of Giardia in the world, and according to the authors, "likely indicate[s] the long-term presence of this parasite in the populations of the Near East."
DOI: Parasitology, 2023. 10.1017/S0031182023000410 (About DOIs).
