There are millions of cases of leprosy (Hansen's disease) worldwide, but predominately in Asia and Africa. The clinical spectrum of Hansen's disease is best characterized by

Leprosy (Hansen's disease) affects primarily skin, peripheral nerves, and mucous membranes. The disease ranges from tuberculoid leprosy, which is characterized by few lesions containing small numbers of acid-fast mycobacteria, to lepromatous leprosy, which is characterized by multiple lesions containing many microorganisms. Chronic pulmonary infection is more characteristic of infection with Mycobacterium tuberculosis than M. leprae.