What Did the Ancient Romans Do for Us? They Gave Us Parasites

'Clean' ancient Romans were crawling with worms, lice and fleas despite their baths, sewage systems and toilets, study proves.

The Romans are credited with introducing toilets to European towns some 2,000 years ago, much like this marble public latrine in Lepcis Magna, Libya.
The Romans are credited with introducing toilets to European towns some 2,000 years ago, much like this marble public latrine in Lepcis Magna, Libya. Craig Taylor

The people of ancient Rome were famed not only for their licentiousness but for their sanitation. Public baths were legion throughout the Roman Empire, and the Romans are also credited with introducing toilets and sewers to European towns some 2,000 years ago. Yet the Romans turn out to have been even more worm-infested than their unwashed peers, and also compared with earlier peoples, say archaeologists.

At least they probably smelled better, says Piers Mitchell of the Cambridge Archaeology and Anthropology Department.

The reasons for the pest infestations were apparently not that they didn’t know how to bathe, but they didn't realize the way they did it and other habits of theirs supported the life-cycle of parasites.

Studies of coprolites (fossil feces) and ancient Roman toilets found unexpectedly high levels of infestations by whipworm, roundworm, and an ameba causing dysentery, writes Mitchell.

If anything, the ancient Romans had even worse infections than their predecessors in the Iron Age. (Yes, worm eggs have hard shells and survive very nicely in fossil stools.)

Nor did their bathing habit, or the Roman laws designed to keep their towns free of excrement and garbage, reduce infestations of fleas, lice and crabs compared with relatively unsanitary folk such as the Vikings, or compared with later medieval populations, writes Mitchell, in a paper published Thursday in the journal Parasitology.

The huge baths of Caracalla, in Rome, were the second largest Roman public baths built in the city between AD 212 and 217, during the reigns of Septimius Severus and Caracalla. The baths remained in use until the 6th century.
Agnete, Wikimedia Commons

"Modern research has shown that toilets, clean drinking water and removing faeces from the streets all decrease risk of infectious disease and parasites," Mitchell says. "So we might expect the prevalence of faecal oral parasites such as whipworm and roundworm to drop in Roman times -- yet we find a gradual increase. The question is why?"

Can't resist that fish sauce

One possibility is that Romans used their feces to fertilize crops, a practice eschewed in modern society precisely because of the propensity to spread human disease.

Human droppings are as good for crop yields as horse manure. But unless the stools are composted for months in advance of use, they contain parasite eggs. Those eggs wind up in the plants and then in the plate.

Possibly the very law requiring feces to be removed from the streets had the very effect of making things worse, because it would be removed straight to the fields, reinfecting the people, Mitchell  speculates.

Another is location, location, location and conditions that a worm would love.

A whipworm egg found in the context of ancient Roman toilets in Turkey.
Piers Mitchell

The engineers of ancient Rome were famous for the hot-water bathhouses they built. Maintenance was another thing. Infrequently changed warm communal waters in the baths would cause accumulation of human dirt and cosmetics in a scum, and we all know what some people do in the bath. These conditions were a boon to the beasts. "Clearly, not all Roman baths were as clean as they might have been," Mitchell sniffs.

Another surprise was the widespread prevalence of fish tapeworm eggs found throughout the Roman empire, well beyond areas where the condition would have been endemic – northern Europe.

Mitchell suspects the reason is that ancient Romans had a huge weakness for an uncooked fish sauce called garum, which was also used in a medicinal context, not that it would cure anything. Garum contained spices, salt and fish and was left to ferment in the sun, which had absolutely no effect on the tapeworm eggs.

Because of the extensive Roman trading network, the fish tapeworm could have spread from its endemic areas throughout the empire. Fish tapeworm eggs were also found in Roman ruins studied in Israel, and could not have arisen from local sea fish, as the parasite is spread by eating fish that spend at least part of their life cycle in fresh water.

Mitchell's conclusion: "Romanization" did alter the balance of disease among the peoples of Europe and the Mediterranean 2,000 years ago, and not necessarily for the better, going by the parasite evidence. "This appears to be a good example of the negative health consequences of conquering an empire," Mitchell stated.

If it quacks like a doctor

So, ancient Romans had worms and lice from head to pubes to toe, but did they try to do anything about it aside from combing? Yes, but not effectively.

They did invent the lice comb, and the famous Roman doctor Galen (130AD - 210AD) described worm infestations that that may or may not refer to the parasites Mitchell found in his study. Whatever they were, his treatment recommendation was utterly useless.

What Have The Romans Ever Given us? (Monty Python)

Today we know theory of spontaneous generation to be farcical, but in fact it was only disproved in the late 17th century. Until that time, people believed that, for instance, if one wrapped wheat in a dirty cloth, one would make mice. (It won't work.)

Galen was therefore well within the theoretical framework of the time when he assumed the worms were created in warm rotting matter by spontaneous generation. He recommended treatment through modified diet (okay), bloodletting (not okay), and medicines believed to have a cooling and drying effect (useless at best), in an effort to restore balance to the 'four humors': black bile, yellow bile, blood and phlegm. It's little wonder that with a little help from Roman "hygiene" and fish sauce, parasites spread throughout the realm.