Researchers have genotyped leprosy through a medieval pilgrim's skeleton
Multidisciplinary analysis also revealed details of medieval life for a pilgrim
In excavating the medieval site of the St. Mary Magdalen hospital cemetery and chapel in Winchester, England, researchers were looking to genotype a strain of leprosy. They wanted to shed light on the origins and evolution of the epidemic that plagued Europe in the Middle Ages.
Among the lesion-ridden skeletons they found and studied, they were intrigued to discover the undisturbed remains of a young man who once traveled a long way to die in a foreign land.
By studying the skeleton of this medieval pilgrim, researchers have been able to genotype the disease, according to a study published Thursday in the journal PLOS Neglected Tropical Diseases. They also discovered that leprosy-causing bacteria have changed little over hundreds of years, possibly explaining the decline in the disease after it peaked in medieval Europe as humans developed resistance.
The 2F strain lineage they genotyped is still associated today with cases in south-central and western Asia. Although leprosy still occurs, it was eliminated as a public health problem in 2000, according to the World Health Organization, which means that there is less than one case per 10,000 people.
Leprosy, which mainly affects the skin, eyes and nerves, is curable with multidrug therapy, which the WHO has made available for free since 1995.
But during the Middle Ages, there was no cure. Although it was not highly contagious, leprosy could spread through droplets from the nose and mouth during close or frequent contact.
“Hospitals at this time were places where people were looked after rather than subject to any medical treatments,” said Simon Roffey, lead study author and lecturer of medieval archaeology at the University of Winchester.
By studying the cemetery of the hospital, the earliest-dated leprosy hospital in western Europe, this eight-year project looks at the wider relationship between leprosy, medieval pilgrimage and disease transmission.
Portrait of a pilgrim
Using multidisciplinary analysis by studying the skeleton with genotyping, radiocarbon dating, biomolecular analysis, osteology and other archaeological methods, the researchers were able to paint a portrait of a young medieval man.
The undisturbed remains of the pilgrim, buried with a symbolic scallop shell, were found under the chapel. The shell, pierced with two holes, was the sign of those who made the pilgrimage to the shrine of St. James in Santiago de Compostela, Spain.
Along with Jerusalem and Rome, Santiago was one of three great pilgrimage sites allowed to distribute the scallop shells. Religious pilgrimages to sites in medieval Europe were at their peak during the 12th century, when an estimated 5,000 pilgrims a day visited Santiago.
Though other skeletons in the cemetery had obviously been moved, the body seems to have been left on purpose, as though he were associated with the chapel itself. The remains, belonging to a man who was between 18 and 25 years old, were designated Sk27 by the researchers from the University of Winchester Department of Archaeology and University of Surrey.
The leprosy strain sampled from the skeleton was also found to be genetically distinct, meaning that in life, he was quite the traveler. Analysis of skull and tooth enamel showed that he was not local to Winchester or even northern Europe and possibly came from southern Europe or northern Africa.
He also showed signs of early leprosy, although unlike with other skeletons in the cemetery, his bones were not riddled with lesions. DNA evidence of the bacteria and skeletal lesions were found only in the area of his feet and legs, but the researchers believe that he suffered from obvious skin and soft tissue lesions and perhaps facial paralysis due to nerve damage. Tests for other pathogens were negative.
Carbon and nitrogen isotope results revealed that his diet was high in animal protein, most likely of the seafood variety. Compared with others in the cemetery who were lacking in such a rich diet, Sk27 was either a man of some means or a newcomer to the population.
“Life would have been increasingly uncomfortable for the pilgrim, and even though he had early stage leprosy, he would have been fully aware of the implications of this,” Roffey said. “For a man who had probably traveled widely, including the arduous journey to Santiago de Compostela, he would have been aware that he was likely to see out the rest of his days in the more sedentary context of the hospital in Winchester.”
Researchers have questioned the link between the increase in pilgrimages and the spread of leprosy. At the time, pilgrims associated visiting religious shrines and sites with miraculous cures and healing, including those who suffered from leprosy.
Winchester itself was attractive in this regard because it was full of shrines and hospitals in the 12th century and was a bustling city in its own right. It was also a key focal point within a network of pilgrim routes.
Now, it is also an attractive site for researchers because over 85% of skeletons in its cemetery had evidence of leprosy, the highest in the country. This also means that the diagnosis rate was high and that the hospital was part of a dedicated response to the epidemic, Roffey said.
What history gets wrong
Due to the unsightly nature of the lesions that leprosy can cause, history tells us that lepers were treated as social outcasts. But Sk27 tells a story of acceptance. He was buried with the rest of the cemetery population rather than separately.
“The presence of a pilgrim burial in the cemetery of a leprosy hospital also challenges modern misconceptions regarding leprosy sufferers as outcasts and that the disease was linked to sinfulness,” Roffey said.
The idea of sinfulness, and the misconception that leprosy was highly contagious, was largely influenced by Victorian medical historians with a segregationist agenda when regarding other colonies, Roffey said. The idea of contagion wasn’t formed until the 14th century, when leprosy was receding. When Sk27 was alive, leprosy was regarded by some to represent Christ-like suffering before death, providing them with a passport to paradise.
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“Our archaeological evidence supports this and indicates that far from being excluded as outcasts, they were treated very much like the religious,” Roffey said. “The wider implications of our research ultimately is that it can help challenge long-held and false notions.”