Leprosy, also known as Hansen's disease, is a devastating chronic infectious disease caused by Mycobacterium leprae and Mycobacterium lepromatus. The disease predominantly affects the skin and peripheral nerves. Left untreated, it may cause progressive and permanent disabilities.
The bacteria are transmitted via droplets from the nose and mouth during close, prolonged and frequent contacts with untreated cases. Leprosy is curable with Multiple Drug Therapy (MDT). The patient stops transmitting the disease when they begin treatment.
In 2024, a total of 172 717 new cases of leprosy were reported across all six WHO regions. Of these, 19 171 new cases (11.1%) were reported in the African region, ranking third after the South-East Asia Region (SEAR) and the Americas Region (AMR). The most vulnerable and high-risk populations are living in the Democratic Republic of Congo, Ethiopia, Madagascar, Mozambique, Nigeria and Tanzania, which together reported more than 1 000 new cases each.
People affected by leprosy are often subject to discrimination and stigmatization.