To people in Western societies leprosy is usually the punchline of a joke. To us leprosy is now rare and fairly treatable, although interestingly around 200 people a year are still diagnosed in the USA.
However Leprosy still affects around 180, 000 people worldwide acutely, with up to a million suffering chronic complications most of them in Africa and Asia. It is a disease that has only been controlled in very recent history, mainly due to increased hygiene practices. Prior to that it has been something that has stalked humanity for almost all of known history.
The earliest recorded account of a disease resembling leprosy appears in an Egyptian papyrus document in 1550 BC. Indian writings also mention a similar illness in 600 BC. It appears that the army of Alexander the Great may have brought leprosy back from India with them - as accounts of it appeared in their writings around this time. Similarly it began to be recorded by the Romans around 62 BC when Pompeii's soldiers came back from Asia minor.