Vindolanda Reveals Intestinal Parasites in Roman Britain

In a remote fortress on the former frontier of the Roman Empire, fossilised sewage has revealed an uncomfortable aspect of military life.

Archaeologists already knew a great deal about Roman weapons, walls and strategy in Roman Britain. Far less visible was what took place inside the latrines. Microscopic analysis of the drainage system at Vindolanda fort, south of Hadrian’s Wall, now indicates that soldiers - and their families - lived with a heavy burden of intestinal parasites around 1,800 years ago.

Vindolanda: the fortress where sewage became a historical record

Vindolanda was a strategically positioned Roman fort near Hadrian’s Wall in northern England. Soldiers sent to guard the Empire’s frontier lived there, alongside women, children and civilians connected to everyday military life.

In 2019, researchers from the Universities of Cambridge, Oxford and British Columbia collected 58 sediment samples from the main drainage channel of the fort’s latrines, which dates from the third century AD. The feature stood beside an aqueduct-fed bath complex and had a drainage system regarded as advanced for its time.

Built up at the base of the drain and preserved for almost two millennia, these sediments provide a kind of health “black box” for the community. They trapped microscopic faecal fragments, food remains, worm eggs and traces of micro-organisms.

In the muddy layers of the latrines, scientists found what ancient texts rarely describe: the quiet impact of intestinal diseases on everyday Roman life.

What the microscopes found at Vindolanda

In the laboratory, the samples were concentrated and inspected under microscopes for helminth eggs - intestinal worms. To identify protozoa, which do not leave visible eggs, the researchers used an immunological test called ELISA (enzyme-linked immunosorbent assay).

The findings were striking:

• Ascaris eggs (human roundworm) in 22% of samples;
• Trichuris eggs (the whipworm) in 4% of samples;
• one sample containing both worm types at once;
• confirmed presence of Giardia duodenalis, a protozoan that causes giardiasis.

This was the first confirmed archaeological detection of Giardia in Roman Britain. Finding three parasites that share the same transmission route leaves little doubt: the environment around the latrines and the water used every day was extensively contaminated with human faeces.

Even with aqueducts, baths and drainage channels, Roman technology could not stop the parasite cycle moving through water and food.

Three parasites, one route of infection

All three identified organisms share a classic means of transmission: the faecal-oral route. In other words, eggs or cysts passed in the faeces of infected people contaminate water, food or surfaces before being swallowed by others.

Ascaris: the persistent roundworm

Ascaris lumbricoides is a roundworm that can grow to several tens of centimetres inside the human intestine. A single female can lay up to 200,000 eggs each day, and those eggs can remain viable in damp soil for years.

After being ingested, they hatch in the small intestine, may migrate through the body, and can lead to:

• recurring abdominal pain;
• changes in appetite;
• malnutrition in severe infections;
• intestinal blockage in extreme cases.

Trichuris: slow, chronic infection

Trichuris trichiura, the whipworm, is less prolific but no less troublesome. It mainly inhabits the large intestine. Infections are generally chronic and subtle, with symptoms including:

• persistent tiredness;
• progressive anaemia;
• intermittent diarrhoea;
• delayed growth in children.

Giardia: the mark of contaminated water

Giardia duodenalis is a single-celled protozoan that signals water contamination. Its cysts are resilient and can readily travel through water from springs, rivers and reservoirs.

Among the people of Vindolanda, giardiasis probably presented as:

• watery diarrhoea;
• wind and abdominal bloating;
• recurring cramps;
• weight loss and impaired nutrient absorption.

Found together in the same sewage system, Ascaris, Trichuris and Giardia indicate constant exposure rather than isolated outbreaks.

How soldiers lived surrounded by worms

Archaeological evidence shows that Vindolanda was not merely a male barracks. Children’s sandals, women’s jewellery and household utensils confirm that families lived inside or around the fort.

Roman soldiers were legally forbidden from officially marrying while in service. In reality, they lived with partners and children. This family life appears in the celebrated wooden tablets recovered at the site, which mention requests for food and clothing, as well as invitations to parties.

In these cramped conditions, with heavy movement through public baths, communal latrines and food-preparation areas, parasites had an ideal setting in which to keep circulating. Children, whose immune systems were still developing, were more severely affected.

Affected group	Main risks	Likely impact at Vindolanda
Children	Dehydration, delayed growth, cognitive impairment	Greater vulnerability to repeated infections
Adult soldiers	Abdominal pain, fatigue, reduced physical performance	Temporary decline in fighting and working capacity
Women and civilians	Anaemia, chronic digestive complications	Overall weakening of community health

Although it is impossible to reconstruct the exact number of infected people, concentrations reached 787 Trichuris eggs per gram of sediment in some locations. Comparative data suggest that between 10% and 40% of the Roman Empire’s population may have been infected with intestinal worms at some point.

A problem extending far beyond Vindolanda

Vindolanda is not an isolated case. Studies at other Roman forts - including Carnuntum in present-day Austria, Viminacium in Serbia and Bearsden in Scotland - reveal a similar pattern: the recurring presence of Ascaris and Trichuris.

Interestingly, more complex parasites, such as tapeworms and certain flukes (trematodes), are almost absent from this type of military site. This suggests that life in garrisons favoured specific forms of transmission, especially those connected with water and the poor management of human waste.

Another important point is that no typically zoonotic parasites - those transmitted from animals to people - were found at Vindolanda. Pigs were raised and eaten there, which could have encouraged this type of contamination. Even so, most pollution appears to have been human in origin.

The fortress, viewed from outside as a symbol of order and discipline, concealed a sanitary reality in which the danger came from within: from the community itself and its waste.

Why Roman engineering could not ensure hygiene

The Romans were renowned for aqueducts, baths and drainage systems. On paper, these should have meant better health. The Vindolanda study shows that the equation was not so straightforward.

Several factors probably helped parasites persist:

• the short distance between latrines, bathing areas and water points;
• water reused for several purposes without adequate treatment;
• soil with a high water table, encouraging sewage seepage;
• limited cleaning, without knowledge of effective disinfectants;
• inconsistent hand-hygiene habits.

In practice, the same structures that helped collect and remove waste could also disperse eggs and cysts in low doses across wide areas, keeping the infection cycle active for years.

What the Vindolanda findings teach public health today

Although this may seem purely historical, the Vindolanda case speaks directly to conditions in many parts of the world today, where basic sanitation remains inadequate. Ascaris, Trichuris and Giardia are still present in numerous countries, including Brazil, particularly in places with open sewers or untreated water.

From a public-health perspective, the study underlines that infrastructure alone does not solve the problem. It must be combined with:

• suitable sewage collection and treatment systems;
• genuinely safe drinking water, tested regularly;
• hygiene education, particularly for children;
• regular deworming programmes in at-risk areas.

A term frequently used in this field of research is palaeoparasitology. It is the study of parasites in ancient settings using microscopic remains preserved in sediments, mummies, coprolites (fossilised faeces) and even latrine dust. The discipline helps explain the history of diseases that still circulate today, acting like a long-term medical record for humanity.

If Vindolanda’s situation were projected on to a modern setting, it would resemble a neighbourhood with sewers and running water, but with illegal connections, leaks and poorly sealed septic tanks contaminating the surrounding ground. The infrastructure exists, but works only partially, allowing persistent worm infections to flourish. The difference is that, on the Empire’s frontier, there were no antibiotics, stool tests or public-health campaigns.