Why were medieval monks so sensitive to intestinal worms? by Brian Handwerk

The monks in Cambridge, England, were almost twice as likely to be infected with these parasites as the average unbathed citizen

The Augustinian friars of medieval England swore to live in poverty, but their friars provided a fairly high standard of collective living. The monks lived in intricate buildings of stone and glass, studied in libraries and ate the products of the rich garden. When naturally needed, they enjoyed dedicated toilets and handwashing facilities, complete with running water systems, a rarity in the wealthiest families of the era. But the latest research on the remains of a female friar buried underground at Cambridge University suggests that the monks were afflicted by a gastrointestinal disease – worms.

Scientists have found centuries-old parasite eggs that are buried along with the bones of monks in the private cemeteries of female friars. To compare their findings with the number of parasites found among contemporaneous civilians in a cemetery near Cambridge, they found the number of parasite eggs. The rate of intestinal helminthiasis among monks is almost twice that of the Cambridge population – despite the fact that many Cambridge residents have similar sanitation facilities and holes in the ground.

Pierce Mitchell, an orthopaedic archaeologist at the University of Cambridge, said: "We expect that if anything, it should be that monks have fewer intestinal parasites, which are transmitted by poor sanitary conditions." "Because they have handwashing and good toilets, poor farmers may not have toilets at all, or even fresh water, they will have more parasites."

Such research may help clarify which factors have historically contributed to parasite affliction, and which factors have helped humans control parasites. This study shows that while sanitary conditions are always key, other factors may also play a role.

Built in the 1280s, the Augustinian Monastery in Cambridge was a major venue for reading and studying manuscripts, hosting clergy from across England and Europe for about 250 years. In 1538, when Henry VIII broke with the Roman Catholic Church, it closed like many English monasteries. What remains is the grave of the deceased monk, shared with the intestinal pests that accompanied them during their lifetime.

Mitchell and his colleagues sampled the soil in the graves, which fell into the body cavity where the intestines once lived during the decomposition. The dirt was mixed with remnants of the abdominal cavity and its contents, including worm eggs that parasitized the intestines while the corpse was alive. Using digital light microscopy, the team screened and sorted ancient parasite eggs in the soil that were still found with each skeleton many centuries later.

"Most intestinal worms have eggs that are very hard, otherwise you would digest them, and they wouldn't be able to reproduce and infect other people," Mitchell said. Mitchell is part of another team that recently discovered parasites in the feces left behind by the builders of Stonehenge 4,500 years ago. "The hard walls that prevent you from digesting them also make it difficult for soil fungi and bacteria to break down these things." So under the right conditions, many of them can survive in the soil for hundreds or thousands of years. ”

While examining the remains of 19 monks buried in the monastery, the team found that at least 11 people (58%) were infected with worms. Most of these monks are from the 13th and 14th centuries. When they similarly tested the remains of 25 adults from the Halloween Necropolis next to the parish church of the castle, only 8 townspeople (32%) carried the parasite.

The research team was not surprised that 30% of medieval Cambridge's citizens suffered from parasites; These figures are consistent with the results of other studies around Europe. But the rate of infection among monks, almost twice the average, is eye-catching.

Why are roundworms and whipworms so infestationally rated? Scientists speculate that the monks may have contracted the parasites when they used their manure as fertilizer, either by emptying their toilets to fertilize crops or by bringing fertilizer contaminated with parasites from human or pig manure into the outside world. These hands-on methods were certainly used in medieval and Roman times, just as they are today in other places around the world where fertilizer options are scarce.

"It's an effective practice, but the problem is that you have to make sure you break the cycle of infection," Mitchell noted. Roundworm parasites can grow up to a foot long, and their eggs are excreted in human feces. When humans eat food or water contaminated with this feces, they become infected and become hosts for a new generation of parasites. To prevent infection, farmers can compost human waste to a temperature sufficient to kill pathogens, making safe fertilizer, but this can be a tricky thing.

Many people infected with helminths may have gastrointestinal discomfort but never know the parasite is the cause. In other cases, worms that are clearly visible in the feces can make the problem disgusting. But medieval medical experts, while aware of the existence of worms, did not know that they could spread from person to person, especially through poor hygiene.

The learned inhabitants of medieval Cambridge wrote that parasites were an unpleasant part of life, and in the process they showed a misunderstanding of the subject. John Stockton, a 17th-century physician, wrote a manuscript arguing that different intestinal worms were caused by an imbalance of the body's four bodily fluids; Blood, phlegm, black bile and yellow bile. "Long, round worms come from excess salt sputum, short, round worms from sour sputum, and short, wide worms from natural or sweet sputum," he wrote. Stockton's treatment includes medicinal plants such as absinthe, which can kill some parasites, but may come at the cost of persistent diarrhea. In the 15th century, a monk named Simon Wells opened his mouth to a more palatable cure, a therapeutic drink made from mole powder. For some, Wells' approach involving small mammals may make living with worms seem like a bad choice.

Scientists delved into many ancient toilets to find evidence of ancient diets and intestinal parasites. Studying this parasite can yield a lot of important information, but it does involve some challenges. For example, one expert noted that the small sample sizes used in such studies make it difficult to draw broader conclusions. Another expert warned that what looks like parasite eggs is sometimes confused with plant or fungal remains.

But studying these pests can provide the best way to control and eradicate them today. This often means improved sanitation, which often reduces the level of harmful parasite problems.

Medieval Cambridge was home to several nuns and nuns, as well as other typical inhabitants of medieval cities, including merchants, craftsmen, laborers, peasants, and even early university students. Centuries later, Cambridge University pioneered efforts to study their past.

Studies like this comparing parasite infection rates in discrete subsets in a single community are rare, because when bodies have been mingled in cemeteries for centuries, it's hard for researchers to know exactly who is who. But the monastery's private cemetery offers a unique opportunity. Except for a few wealthy outsiders, who paid for the privilege of being buried on sacred ground, burials were mostly limited to brothers who lived there. These people were easily spotted, but overlooked in research because they did not wear revealing robes and the existing rusty belt buckles, with which monks in monasteries were buried.

These unique historical environments, like the castle toilets that preserve the parasites excreted by the crusaders, provide us with more opportunities to learn how different humans responded to intestinal pests that were very common in the past and help us eliminate their descendants, who still live with us today and are very uncomfortable.