At https://phys.org/print449220213.html … a medieval leprosy hospital at Odense in Denmark has been excavated and some of the bones have been analysed. The hospital was the final resting place of people that died from the disease around 700 years ago – caused by an infection of Mycobacterium leprus bacterium. Scientists have found traces of the infection in the skeletons. Results of the study on well preserved DNA will, it is hoped, shed light on the outbreak that ravaged Denmark and large areas of Europe, and also on how diabetis developed (which still impacts the modern world).
Leprosy can lead to stunted hands and feet, ugly weeping wounds, collapsed noses and blindness. To the surprise of the researchers the ancient bones were infested by several different types of the bacteria. These different strands developed outside Denmark – when people from outside the area brought the streams into Scandinavia. Leprosy is an old disease – mentioned in the Bible for example and in old Egyptian texts. It was in India as early as 2000BC and there is therefore the possibility it could have been introduced into Denmark (and elsewhere in Europe) by the returning crusaders. The disease disappeared from Denmark during the 1500s for reasons unknown. Of course, the Black Death became a bigger problem that leprosy – and that too disappeared (eventually). See Science Nordic for more information.
It is also a coincidence that as I printed off the above link that I came across another article on leprosy – this time in the Australian science magazine Cosmos. New research shows than many armadilloes in the Brazilian Amazon basin carry the bacteria that causes leprosy – published in PLOS Neglected Tropical Diseases journal. We are told that leprosy is slow but develops into a chronic disease that causes the well known skin lesions and nerve damage. It can lead to muscular atrophy, paralysis and blindness and recent evidence seems to show it affects immune cells in the vicinity of nerve endings. The cells that destroy the protective myelin layer on the nerves and nerve fibres. Most people are able to fight it off, apparently, before it can fully develop – but some people cannot. In 2016 80% of all cases occurred in India, Indonesia, and Brazil. It is thought it is a disease that is transported by other humans – and animals (such as armadilloes). The latter is trapped as bush meat and many people in Brazil eat the armadillo. It is thought that this may be responsible for high leprosy levels in the country.