unsanitary conditions

They were infected by roundworm, whipworm, and microscopic protozoans called Giardia duodenalis.

Third-century baths and latrine block at Vindolanda, the Roman fort close to Hadrian’s Wall in the UK. Credit: Vindolanda Trust

It probably sucked to be a Roman soldier guarding Hadrian’s Wall circa the third century CE. W.H. Auden imagined the likely harsh conditions in his poem “Roman Wall Blues,” in which a soldier laments enduring wet wind and rain with “lice in my tunic and a cold in my nose.” We can now add chronic nausea and bouts of diarrhea to his list of likely woes, thanks to parasitic infections, according to a new paper published in the journal Parasitology.

As previously reported, archaeologists can learn a great deal by studying the remains of intestinal parasites in ancient feces. For instance, in 2022, we reported on an analysis of soil samples collected from a stone toilet found within the ruins of a swanky 7th-century BCE villa just outside Jerusalem. That analysis revealed the presence of parasitic eggs from four different species: whipworm, beef/pork tapeworm, roundworm, and pinworm. (It’s the earliest record of roundworm and pinworm in ancient Israel.)

Later that same year, researchers from the University of Cambridge and the University of British Columbia analyzed the residue on an ancient Roman ceramic pot excavated at the site of a 5th-century CE Roman villa at Gerace, a rural district in Sicily. They identified the eggs of intestinal parasitic worms commonly found in feces—strong evidence that the 1,500-year-old pot in question was most likely used as a chamber pot.

Other prior studies have compared fecal parasites found in hunter-gatherer and farming communities, revealing dramatic dietary changes, as well as shifts in settlement patterns and social organization coinciding with the rise of agriculture. This latest paper analyzes sediment collected from sewer drains at the Roman fort at Vindolanda, located just south of the defense fortification known as Hadrian’s Wall.

An antiquarian named William Camden recorded the existence of the ruins in a 1586 treatise. Over the next 200 years, many people visited the site, discovering a military bathhouse in 1702 and an altar in 1715. Another altar found in 1914 confirmed that the fort had been called Vindolanda. Serious archaeological excavation at the site began in the 1930s. The site is most famous for the so-called Vindolanda tablets, among the oldest surviving handwritten documents in the UK—and for the 2023 discovery of what appeared to be an ancient Roman dildo, although others argued the phallus-shaped artifact was more likely to be a drop spindle used for spinning yarn.

The worms crawl in

Per the authors of this latest paper, analyzing fecal matter (paleoparasitology) from Roman Britain has thus far largely been done at urban centers such as London and York, and the only site where it has been done along Hadrian’s Wall is Carlisle. Vindolanda’s exceptional preservation makes it a prime candidate for learning more about the transmission of parasites and resulting gastrointestinal diseases among the Roman military manning the northern frontiers at that time.

The material was collected in 2019 from the main drain carrying latrine waste from the bath house toilet down to the stream and valley to the north. The team also excavated what was left of a 17th-century farmhouse, where they found sealed deposits from a previous third-century bath house drain at the site. They collected and analyzed 58 samples of sediment from those drains, as well as one sample collected from a nearby fort ditch circa 90 CE.

The analysis revealed that 28 percent of the samples contained eggs from either roundworms or whipworms, intestinal parasites typically spread as a result of poor sanitation, either via food, drink, or hands that come in contact with fecal matter. The first-century fort sample also contained roundworms and whipworms. Using a biomolecular method that binds antibodies to proteins produced by single-cell organisms, they found traces of a microscopic protozoan parasite called Giardia duodenalis. According to the authors, this suggests Roman solders regularly suffered from diarrhea and malnutrition.

Even having communal latrines and a sewer system apparently didn’t prevent parasitic transmission. “While the Romans were aware of intestinal worms, there was little their doctors could do to clear infection by these parasites or help those experiencing diarrhoea, meaning symptoms could persist and worsen,” said co-author Marissa Ledger of the University of Cambridge. “These chronic infections likely weakened soldiers, reducing fitness for duty. Helminths alone can cause nausea, cramping and diarrhea.”

DOI: Parasitology, 2025. 10.1017/S0031182025101327 (About DOIs).

Jennifer is a senior writer at Ars Technica with a particular focus on where science meets culture, covering everything from physics and related interdisciplinary topics to her favorite films and TV series. Jennifer lives in Baltimore with her spouse, physicist Sean M. Carroll, and their two cats, Ariel and Caliban.