According to a new study, parasitic worms, such as those found in the 15th century relics of King Richard III, were relatively common among medieval Europeans.
Susie Kearley / World Stock Photo
By Michael Price
Finger-shaped roundworms are a curse in less economically developed countries, where they cause diarrhea, stunt growth and even death in children. A new study suggests that these parasites were as common in medieval Europe as they are today, suggesting that later improvements in hygiene and sanitation in Europe proved to be enough to win them over.
Roger Pritchard, a parasitologist at McGill University who was not involved in the work, says the new study is “comprehensive and well done.” It confirms, he says, that Europe’s successful eradication efforts are not just the result of naturally low parasite numbers.
The two most insidious roundworms – whipworms and hookworms – infect the intestines and expel their eggs from the feces, where they contaminate soil, crops and water supplies. Currently more than 1.5 billion people are affected.
This parasitic worm, which belongs to a group called helminths, has been parasitizing humans for thousands of years. Scientists have also placed them in medieval bones and feces in the remains of King Richard III. Although researchers knew that parasites were there, they did not have a good way of estimating their prevalence.
In the new study, Oxford University zoologist Adrian Smith and colleagues embarked on an ambitious parasitic journey. The team collected about 600 clay samples from the pelvic regions of skeletons buried in cemeteries in the Czech Republic, Germany and the United Kingdom between the 7th and 18th centuries. As the body decomposes, Smith explains, its intestines settle along the pelvic surface, making it a good place to find any parasitic eggs that went to the grave with their host.
Researchers then analyzed the DNA in those samples, today finding the genetic traces of two common types of parasitic worms locally in many countries: the whipworm Trichuris trichura, And various hookworms Ascaris.
After examining the DNA of the specimens, the scientists looked closely at the specimens under a microscope and confirmed the presence of significantly intact parasitic eggs. Trichurios “Looks like an American footballer,” Smith explains. Ascaris Is a round, lumpy orb. All told, the team found that about 25% of the individuals were infected Tricuris, And with about 40% Ascaris, And it remained fairly stable over time, even in the 18th century.
That’s compared to the broader estimates for the same parasites in sub-Saharan Africa, Mexico, South America, East Asia and other countries today, researchers reported last week. PLOS Neglected Tropical Diseases.
Chemotherapeutic drugs developed in the 1960s may have eradicated the worms, but medical records state that Europe was largely helminth-free in the early 20th century (although it was filled in the trenches of World War I). This suggests that improvements in plumbing, sanitation and sanitation in Europe have made a difference, concludes Smith and his colleagues. And that, in turn, strengthens the World Health Organization’s call for reforms in other nations, along with other groups, he says. “Such changes in Europe are very powerful.”
