Leprosy or Hansen’s disease is caused by the bacterium Mycobacterium leprae and it is commonly known as Ma-Feng (痲瘋), Lai disease (癩病), or Thái ko in Taiwanese (癩哥). We still do not know how leprosy is contracted. But it is a chronic, easily curable, and difficult to contract disease. Ninety percent of people in the world are immune to leprosy. People who have received the BCG (​Bacillus Calmette-Guérin) vaccine also have a degree of resistance to the disease.​ Leprosy can harm human skin, mucosa, and surrounding nerves, and infected parts of the body may become numb, uncontrollable, and disabled. But if patients receive treatment early, leprosy can be fully cured.

 

  Mycobacterium leprae was discovered in 1873 by the Norwegian physician G. A. Hansen. T​he first International Leprosy Conference​ in Berlin confirmed that leprosy is infectious and advocated the establishment of sanatoriums to contain it. The government of Japan also sent researchers to the conference who brought its findings and recommendations back to East Asia. Chaulmoogra oil was introduced at the third International Leprosy Conference in 1923 to treat the disease. Dr. Gueshue-Taylor brought this treatment to Taiwan in the 1920s.

 

  Starting from the 1940s, substances such as Dapsone (Diammino Diphenyl Sulphone, DDS) and Rifampicin and Clofaziminekill were developed to control and kill ​Mycobacterium leprae, respectively. As a result, leprosy became curable. Today, Multidrug Th​erapy (MDT) has become the standard treatment for leprosy.