Just the thing for a cheerful dinner discussion. I recently read a book on The Black Death in which I discovered that there was a controversy over whether the Black Death was the same disease that’s now known as bubonic plague. There’s a similar controversy over leprosy, and it goes in both directions timewise: is the disease known as leprosy in biblical times the same as the disease known as leprosy in medieval times, and the same as the modern Hansen’s disease? The ancient Greeks distinguished two kinds of leprosy; one was almost certainly the filarial disease now known as elephantiasis, and the other was skin disease that might or might not have included Hansen’s disease. The geographic pattern appears to have changed with time; it was first a warm climate disease, and this book suggests that returning Crusaders may have brought it back to Europe. However, by latter medieval times the endemic areas were in colder climates - England and Scandinavia. It was never an epidemic in sense that plague or smallpox was, but the incidence got up to two or three cases per thousand - maybe.


The “maybe” part is there because it’s not clear that all the people diagnosed with leprosy in medieval times had it. Leprosy was diagnosed by a priest and members of the congregation, so if there was somebody in the parish who was annoying or unlikeable or just plain odd, they could be sent off to a leprosarium. The accused could get a doctor’s certificate stating that they were “clean”, but they had to do this at their own expense; this might mean a journey from Cornwall to London or the Aland Islands to Stockholm which would probably be beyond the means of your average leper.


In England, leprosaria were typically religious institutions and the lepers were lay brothers and sisters. The lepers were generally put to work chanting prayers (sometimes up to 250 a day) for the soul of the founder, and could be punished if they failed to keep up the prayer quota. As the incidence of the disease diminished, some of these places experienced a leper shortage, with the staff outnumbering the lepers two or three to one.


The last third of the book discusses disease identification and concludes that medieval leprosy was the same as modern Hansen’s disease. Archeological investigations of leper cemeteries show a large fraction of the skeletons have bone changes identical with those seen in modern patients. (Interestingly, the facial bone changes were discovered in the leper cemetery first, which then led doctors to find them in X-rays of modern patients).


This is an older (1977) book, so there’s probably more recent information. It’s still pretty interesting. ( )