Leprosy is a disease caused by the bacterium Mycobacterium leprae. Leprosy is often also referred to as Hansen's disease, after the discoverer of the bacterium. While in ancient history, the term leprosy has been used to denote a wide range of afflictions that cause boils, sores, or other skin diseases, in modern usage it refers exclusively to Hansen's disease as caused by Mycobacterium leprae. While the exact mode of transmission for leprosy is unknown, most people believe the bacterium passes through moisture exuded from the body.

There are two prevalent myths about leprosy, both of which are totally false. The first is that leprosy is incurable. In truth, leprosy is treatable by using a regimen of drugs. The first real treatments for leprosy, using a drug called dapsone, were established in the 1940s. The World Health Organization (WHO) provides this Multi Drug Therapy (MDT) to any country in need as part of their ongoing efforts to eliminate leprosy as a world health problem.

The second myth is that leprosy is extremely contagious. In actuality, most people are naturally immune to the disease, and for those that are not, transmission is still unlikely. It is estimated that more than 90% of the world's population possesses total immunity to leprosy. For those that are susceptible, close contact with infected persons, particularly those exhibiting strong signs of the disease, is recommended against. In no way, however, is transmission anywhere near as easy as most people believe -- in the popular mindset, simple contact with a leper virtually guarantees becoming infected oneself, a scenario that is highly unlikely, if not outright impossible.

Since the World Health Organization has made a determined effort to eliminate the threat of leprosy worldwide, incidence of the disease has been drastically reduced. Between 2003 and 2004 there was a reduction of more than 20% in new cases, down to just over 400,000 worldwide. Of the remaining cases of leprosy, the majority are found in Africa, Latin America, and Asia, with nearly 90% of all leprosy cases found in Nepal, Brazil, Madagascar, Mozambique, and Tanzania. India has proven a strong model for what education and disbursement of drugs can do to eliminate leprosy, with the number of cases in that country reduced greatly over just a few years.

One of the most difficult challenges for groups like the World Health Organization to overcome in their fight against leprosy is the deeply entrenched social stigma associated with the disease. In many cultures, leprosy is viewed as a divine punishment, and those afflicted are often ostracized from society as a whole. Leper colonies and asylums have existed in many countries for many hundreds of years as places for a group to ship off their lepers to and let them die of the disease in exile. While leper colonies primarily exist in developing nations such as the Philippines and India, in recent years the Japanese government has come under intense criticism for their own colonies.

In general, the global outlook on leprosy seems to be very favorable, with the World Health Organization's "Final Push" program making significant inroads, even in countries once thought to be virtually beyond assistance. If things continue as they are, leprosy may go the way of smallpox and polio, becoming nothing more than a historical artifact.