Leprosy is an infectious disease that has affected people throughout history and one which is marked by painful and disfiguring symptoms. Throughout history, people with leprosy have been treated with fear and disdain with many cultures banning or shunning the victims of this disease. That stigma has slowed the study of the disease, since, throughout much of history, treatment was a low priority for some cultures. The ancient civilizations of China, Egypt, and India feared the disease, presuming it to be incurable and highly contagious.In truth, leprosy isn't as contagious as the myths suggest. The disease can't be transferred from person to person, unless there's repeated close contact with leakage from the nose and mouth of a leper. Additionally, the disease most often affects children, so it's rare for an adult to contract the disease. The World Health Organization reports that there are 180,000 cases of leprosy worldwide today with most cases occurring in Africa and Asia. In the United States, approximately 100 individuals are diagnosed with leprosy each year. Most incidences occur in the southern states, California, Hawaii, and outlaying U.S. territories.
The disease is caused by exposure to Mycobacterium leprae (M. leprae), a bacteria that grows slowly in the body, once a person has been exposed. The condition may also be called Hansen's disease, named after the scientist credited for discovering M. leprae in 1873. Since the bacteria grows slowly, it can take three to five years for symptoms to develop, after a person has been exposed. In some cases, it can even take up to 20 years for symptoms to present. For that reason, it can be nearly impossible to know where or when exposure to the M. leprae bacteria occurred. This slow incubation period is also the reason it's important to be aware of the following early signs of infection.
