Analyzing a 500-year-old latrine in the Christian quarter of the old city of Jerusalem, researchers found evidence of some species of intestinal parasites that seem to have been “imported” from medieval Europe.
Of the six species of parasitic eggs detected – including large quantities of roundworm and whipworm, both spread by faecal contamination of food and thought to be endemic to the region at the time – two had been normally very common in northern Europe, but almost absent in the Middle East.
“The analysis of this fifteenth century latrine in Jerusalem provides a vivid glimpse of the infectious diseases suffered by the people who used it,” reads the study.
The parasites in question are Entamoeba histolytica and fish tapeworm, explains the research published in the International Journal of Paleopathology. The researchers believe long distance travelers had taken these parasites with them as they journeyed to Jerusalem.
The fish tapeworm was prevalent in Europe and often eaten raw, smoked or pickled – which doesn’t kill the parasite. But, as per Arabic texts of the time, in inland cities such as Jerusalem, fish was either not commonly eaten, or was thoroughly cooked before being consumed. The cooking kills the parasite and prevents its spread.
The researchers found pieces of Italian pottery in the same cesspool, which – they believe – point to strong trading or religious links between Europe and Jerusalem during the late 1400s, according to the official press release with details of the study. Based on that, the researchers hypothesise that the latrine was either a town house owned by local merchants who traveled to Europe, contacting the parasite while there, or a hostel where European merchants or pilgrims stayed.
“While we can only suggest reasons as to why people made these journeys between northern Europe and Jerusalem’s Christian quarter, it does seem they brought with them unsuspecting hitchhikers in their intestines,” Piers Mitchell, biological anthropologist and author of the study, says.
The researchers also found quantities of Taenia parasite eggs, indicating pork or beef tapeworm. The Mamluk Period (1250-1516 AD) was Islamic but pigs would have still been consumed in the Christian quarter.
Though its effects varied, “a heavy load of these parasites in children, however, can lead to malnutrition, reduced intelligence and stunted growth. Dysentery may cause diarrhea and abdominal cramps for a week or two and then settle, or it may cause death from dehydration and septicaemia,” says Mitchell.
“This research highlights how we can use preserved parasite eggs in ancient toilets to spot past migrations and the spread of ancient diseases. Jerusalem’s importance to Christians in medieval Europe made it a key destination for both pilgrimage and trade. We can see these travellers took unexpected guests along with them.”