Since the beginning of time, Hansen's disease has been recognized as a problem. Reported in Egypt in as early as 1350 BC, Lepresy is the oldest disease known to man; this is according to the Guinness World Records. Frequently, Lepers have lived outside of society. This is partly due to the fact that for a long time the disease was believed to have been caused by a divine, often times associated with demons, curse or punishment. This idea changed in the middle ages, when people started to beleive that lepers are loved by God, and that it is humans that have cursed them

Another reason for secluding the Lepers what that in the past it was believed that leprosy was highly contagious. If was even taken to the extent that leprosy could be spread by the glance of a leper or an unseen leper standing upwind of healthy people. Today we know that the disease is much less contagious than we once believed in the past. Lepresy is caused by a mycobacterium that will multiply at a very slow rate. The disease mainly affects the skin, nerves, and mucous membranes. The organism has never been grown in cell culture, because of the difficulty that is involved with doing so. This difficulty is as a result of the fact that the organism is an obligate intra-cellular parasite. This means that it lacks many necessary genes for independent survival. This is also evident and provides proof for it having such a slow rate of replication.

Uncertain today, is the method of transmission of Hansen's disease. Many people beleive that it is spread person to person in respiratory droplets. What we do know though, is that most of the population is naturally immune to the disease. The disease is chronic, and often times patients are classified as having paucibacillary, which is a form of multibacillary Hansen's disease.