The word comes from the Greek "lepra", meaning "scale" or "flake". It is also known as Hansen's disease, named after its discoverer Gerhard Hansen.
Leprosy is transmitted via the respiratory tract or skin contact and mainly affects the skin, the peripheral nerves, mucosa of the upper respiratory tract and the eyes, afflicting all ages and both sexes. The incubation period can last anywhere between three months and 40 years, with the average being three to five years. Leprosy is chronic, but much less contagious than has been commonly supposed. It is curable and if detected early and treated with a prescribed duration of drug therapy, it will not cause any permanent disability.
Leprosy is one of the world's oldest known diseases, known to the ancient civilizations of China, Egypt and India. Leprosy was also rampant during the 13th century in Europe. Historically, it is one of the most stigmatized diseases with a reputation of being highly contagious, disfiguring and incurable. In the past leprosy sufferers were banished to leper colonies. Unfortunately, this practice still exists is some countries today,[Citation Needed] even though leprosy is now curable and is not considered highly contagious.
Worldwide there are 290,000 leprosy cases being treated as of January 2005; according to the World Health Organization, 75 percent of leprosy cases arise in nine countries in Africa, Asia, and Latin America. Significant illegal immigration occurs from of these countries to the United States, potentially circumventing public health measures concerning leprosy as well as other contagious diseases.
"According to Dr. Barbara Stryjdwska, Clinician at the National Hansen’s Disease Programs in Louisiana, there are only approximately 150 new leprosy cases each year in the United States, and most of these are in immigrants coming from countries where Hansen’s Disease is endemic. In 2002, 96 cases were reported to the Center for Disease Control and Prevention. The incidence may be greater however, because many patients do not want to be reported because of their immigrant status. Additionally, if patients do not seek or purchase treatment, they are hard to be tracked. ... Because leprosy is such a small problem in the United States, and since 90% of cases are imported (immigrants from countries where leprosy is endemic), there is little reason for a leprosy vaccine to actually be utilized in the United States ...."
- "Doctor says he treated woman with leprosy," The Macon Telegraph (Georgia), June 7, 2007.