Imagine a 2- to 3-foot long (0.6- to 1-meter) worm slowly working its way out of your body… with the possibility of other worms doing so in the future. Such is the horror of the guinea worm, which has been plaguing mankind for millennia.

Some of the oldest guinea worms are known from the calcified remains of one found in an ancient Egyptian mummy and another possible case mentioned in the Old Testament of the Bible. Now, scientists are studying a painting from an Italian church with what appears to be the oldest image of a guinea worm – one coming out of the leg of a 14th century French saint.

The worm is not presently known in Italy, and its range is limited to the countries of South Sudan, Chad, Mali, and Ethiopia in Africa, where great progress has been made in eradicating them. Although it is painful, the worm does not kill the parasitized person.

Some Africans drink from stagnant water, which is the source of the guinea worm. ( Carter Center photo )

The parasitic condition is called dracunculiasis. It seems to be clearly depicted in the altarpiece in the Painting Gallery in Bari in the southern Puglia region of Italy. The painting is of St. Roch, a 14th century Frenchman who legends say visited Italy and healed plague victims, but who later got the plague himself.

Some paintings of St. Roch show a bubo, or pustulent sore from the plague. But this altarpiece painting also shows a long worm coming out of his upper thigh.

St Roch. Oil painting by Santa Cruz. ( Wellcome Images ) This depiction of St. Roch doesn’t show dracunculiasis, but a pustulent sore instead.

"We believe instead that the painter portrayed an ancient case of dracunculiasis, an infectious disease caused by a nematode worm, the Dracunculus medinensis , well known in antiquity," Raeffele Gaeta and colleagues wrote in their study in the Journal of Infection , as quoted in Live Science.

In the Old Testament of around 1450 BC, the worm is mentioned, calling it the “fiery serpent,” says the Carter Center . It is also identified in the Ebers Papyrus of ancient Egypt from 1550 BC. That document suggests removing the worm by winding it around a stick, a method still in practice today.

The World Health Organization said by the mid-1980s there were 3.5 million cases of dracunculiasis in 20 countries. Seventeen of these nations were in Africa. The number dipped below 10,000 by 2007, and by 2016 there were only 25 cases in the world.

Perhaps the most horrifying aspect of the parasite is that people who have it seek out water to quell the burning sensation as it exits the body, but doing that makes the worm discharge larvae, which causes the cycle to recur.

The worm after is has been partially wound out of the body with a stick. Part of the worm remains in the foot. (Otis Historical Archives photo/ CC BY 2.0 )

The Carter Center describes the full horror of the disease:

“Considered a neglected tropical disease, Guinea worm disease (dracunculiasis) is a parasitic infection caused by the nematode roundworm parasite Dracunculus medenisis. It is contracted when people consume water from stagnant sources contaminated with Guinea worm larvae. Inside a human's abdomen, Guinea worm larvae mate and female worms mature and grow. After about a year of incubation, the female Guinea worm, one meter long, creates an agonizingly painful lesion on the skin and slowly emerges from the body. Guinea worm sufferers may try to seek relief from the burning sensation caused by the emerging worm and immerse their limbs in water sources, but this contact with water stimulates the emerging worm to release its larvae into the water and begin the cycle of infection all over again.

Guinea worm is a particularly devastating disease that incapacitates people for extended periods of time, making them unable to care for themselves, work, grow food for their families, or attend school.”

However, the Carter Center also reports that there is hope that dracunculiasis is set to become the second disease, after smallpox, to be eliminated. It is also the first to be eradicated without use of any medications because there are no known medications for it.

Top image: A painting of 14th century St. Roch shows the dracunculiasis worm exiting the upper part of his leg. Source: Raeffele Gaeta

By Mark Miller