What can parasite eggs preserved in medieval poop tell us about human history?

Parasite eggs preserved in medieval poop may not be everyone’s cup of tea, but for Marissa Ledger, they are a treasure trove of information. As a biological anthropologist and post-doctoral fellow at McMaster University’s Ancient DNA Centre in Hamilton, Ont., Ledger is fascinated by the insights that ancient fecal material can provide about human history.

Recently, Ledger and her Belgian colleagues made a groundbreaking discovery while examining the remnants of a medieval latrine in Bruges, Belgium. They found thousands of parasitic eggs in the ancient toilet, revealing a wealth of information about the trade networks and daily life of the medieval period.

The latrine, located in a building known as the Spanish nation house, was home to Spanish traders who were active in Bruges from the late 15th century onwards. Excavated in 1996, the latrine’s contents were only recently studied using modern technology. Ledger’s analysis of soil samples from the latrine revealed thousands of parasitic eggs in just one gram of soil, indicating that multiple individuals using the washroom were infected with different parasites.

One particularly intriguing find was the presence of Schistosoma mansoni, a water-borne parasitic flatworm typically found in Africa and South America. The presence of this parasite in Bruges suggests a link to Africa during the medieval period, likely through trade routes or the Atlantic slave trade.

While the discovery of parasite eggs in medieval poop may seem unusual, it provides valuable insights into human migration patterns and the spread of diseases throughout history. Understanding how parasites and diseases have evolved and spread over time can help modern doctors treat and prevent them more effectively.

Kirsten Bos, a physical anthropologist specializing in ancient DNA and infectious diseases, notes that Schistosoma mansoni likely did not spread within Belgium due to the absence of freshwater snails needed for its life cycle. Nonetheless, the presence of this parasite in medieval Bruges sheds light on the city’s international connections and the complexities of life in a medieval urban center.

The findings from the medieval latrine in Bruges underscore the importance of studying organic material to learn about past populations’ diet, health, hygiene, and mobility. As researchers continue to explore ancient toilets and cesspits, they uncover new insights into the lives of people in the past and the global connections that shaped their world.

In conclusion, the study of parasite eggs preserved in medieval poop may not be glamorous, but it offers a unique window into the past. By analyzing ancient fecal material, researchers like Marissa Ledger are piecing together the puzzle of human history one parasite egg at a time.