Researchers analyzing ancient sewer drains at the Roman fort of Vindolanda near Hadrian’s Wall have found clear evidence that people living at the site were infected with three intestinal parasites: roundworm, whipworm, and Giardia duodenalis.
All three parasites spread through poor sanitation, typically when food, water, or hands are contaminated with human feces. Roundworms can grow to 20-30cm in length, while whipworms reach about 5cm. Giardia duodenalis is a microscopic protozoan parasite known for causing outbreaks of diarrhea. This discovery marks the first confirmed evidence of Giardia duodenalis in Roman Britain.
Vindolanda and Rome’s Northern Frontier
Vindolanda was located near Hadrian’s Wall in what is now northern England. Hadrian’s Wall was built by the Romans in the early 2nd century AD to protect the province of ‘Britannia’ from northern tribes and remained in use until the late 4th century. The fort itself sits between Carlisle and Corbridge in Northumberland, Britain.
The wall stretches east to west from the North Sea to the Irish Sea and was built with forts and towers placed at regular intervals. These defenses were manned by infantry, archers, and cavalry units drawn from across the Roman Empire.
A Site Known for Exceptional Preservation
Vindolanda is well known for the remarkable preservation of organic materials within its waterlogged soil. Archaeologists have uncovered more than 1,000 thin wooden writing tablets that record daily life at the fort, along with over 5,000 Roman leather shoes.
How the Sewer Samples Were Studied
The parasite investigation focused on sediment collected from a sewer drain connected to a latrine block at a 3rd century CE bath complex. The work was carried out jointly by researchers from the universities of Cambridge and Oxford and published in the journal Parasitology.
Scientists collected 50 sediment samples along the drain, which measured about nine meters and carried waste from the communal latrine to a stream north of the fort. Objects recovered from the drain included Roman beads, fragments of pottery, and animal bones.
The samples were divided between laboratories at Cambridge and Oxford, where researchers examined them under microscopes to search for ancient helminth eggs. Helminths are parasitic worms that infect humans and other animals.
Evidence of Worms and Giardia Infection
About 28% of the samples contained eggs from either roundworm or whipworm. One sample showed evidence of both species. That same sample was further tested using a bio-molecular method known as ‘ELISA’, which works by using antibodies that bind to proteins produced by single-celled organisms. This test revealed traces of Giardia duodenalis.
The research team also examined sediment linked to an earlier fort dating to the 1st century CE. That fort was built around 85 CE and abandoned by 91/92 CE. The sample came from a ditch that formed part of the fort’s defensive system and contained both roundworm and whipworm eggs.
How Parasites Affected Roman Soldiers
“The three types of parasites we found could have led to malnutrition and cause diarrhea in some of the Roman soldiers,” said Dr. Marissa Ledger, who led the Cambridge portion of the study as part of her PhD at the University of Cambridge’s Department of Archaeology.
“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 diarrhea, meaning symptoms could persist and worsen. These chronic infections likely weakened soldiers, reducing fitness for duty. Helminths alone can cause nausea, cramping, and diarrhea.”
Study senior author Dr. Piers Mitchell, an Affiliated Scholar at Cambridge’s McDonald Institute for Archaeological Research, explained that Giardia could have caused serious illness during warmer months. “Some soldiers could have become severely ill from dehydration during summer outbreaks of Giardia, which are often linked to contaminated water and can infect dozens of people at a time. Untreated giardiasis can drag on for weeks, causing dramatic fatigue and weight loss.”
Mitchell also noted that “The presence of the fecal-oral parasites we found suggests conditions were ripe for other intestinal pathogens such as Salmonella and Shigella, which could have triggered additional disease outbreaks.”
How Vindolanda Compares to Other Roman Sites
According to the researchers, the dominance of fecal-oral parasites at Vindolanda closely matches findings from other Roman military sites, including Carnuntum in Austria, Valkenburg on Rhine in the Netherlands, and Bearsden in Scotland. In contrast, large Roman cities such as London and York show a wider variety of parasites, including fish and meat tapeworms.
“Despite the fact that Vindolanda had communal latrines and a sewer system, this still did not protect the soldiers from infecting each other with these parasites,” said Dr. Patrik Flammer, who analyzed samples at the University of Oxford.
What Ancient Parasites Reveal About Roman Life
“The study of ancient parasites helps us to know the pathogens that infected our ancestors, how they varied with lifestyle, and how they changed over time,” said Prof Adrian Smith, who led the Oxford laboratory involved in the research.
Dr. Andrew Birley, CEO of the Vindolanda Charitable Trust and leader of ongoing excavations at the site, said the findings continue to reshape our understanding of life on Rome’s northern frontier. “Excavations at Vindolanda continue to find new evidence that helps us to understand the incredible hardships faced by those posted to this northwestern frontier of the Roman Empire nearly 2,000 years ago, challenging our preconceptions about what life was really like in a Roman frontier fort and town.”
W. H. Auden’s well-known poem about a miserable Roman soldier guarding a rain-soaked wall in northern Europe mentions “lice in my tunic and a cold in my nose.” Based on this research, serious stomach trouble could easily be added to that list.
Reference: “Parasite infections at the Roman fort of Vindolanda by Hadrian’s Wall, UK” by Marissa L. Ledger, Patrik G. Flammer, Adrian L. Smith, Andrew Birley and Piers D. Mitchell, 2 December 2025, Parasitology.
DOI: 10.1017/S0031182025101327
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2 Comments
I was taught that Roman soldiers used short tabbing swords and large slightly curved rectangular shields as well as a stabbing spear and a heavier throwing spear. That picture of a RS using a long sword designed for slashing and waving in the air a small round shield on his left arm just ain’t right.
For all the Roman’s believed they were clean by bathing and shaving,the same can’t be said about hygiene after going to the toilet then eating food,but they were ignorant of these bacteria and viruses that beset them,I wonder if they were better of in sunny Italy,was there this infection there too?