Leprosy (Hansen’s disease) is caused by the bacillus Mycobacterium leprae that multiplies very slowly. The incubation period of the disease is often five years or more and symptoms can take as long as 20 years to appear. More than 200,000 new cases per year are reported globally, with most of the cases found in low-income communities in India, Brazil and Indonesia. The disease mainly affects the skin, the peripheral nerves, mucosa of the upper respiratory tract and the eyes. Leprosy is curable and early treatment with multidrug therapy (MDT) usually prevents disability. When left untreated the disease can cause progressive and permanent damage to the skin, nerves, limbs and eyes. Once peripheral nerves are affected, loss of sensation can occur in eyes, hands and feet. As a result, injuries may go unnoticed (i.e. burns or cuts), become infected and lead to permanent impairments, including blindness, shortening of fingers and toes, contractures of fingers and toes and weakness or paralysis of hands and feet.

Treatment halts the progression of the disease itself, but it cannot reverse these impairments. New nerve damage may even occur after completing leprosy treatment, due to immunological reactions to the bacterial antigen, which is cleared from the body only very slowly. While contractures of fingers and paralysis of hands or feet may be restored with reconstructive surgery, any loss of feeling in hands and feet is permanent, unless treated very early. This means that persons with nerve impairment can easily injure themselves repeatedly, which in turn may lead to the above secondary impairments. The total number of individuals who live with leprosy-related chronic disfigurement and physical disabilities is estimated to be between one and two million. Notwithstanding, worse than the physical impairments is social exclusion due to leprosy-related stigma which is common in most endemic areas. The stigma and social exclusion leads to many forms of discrimination and human rights abuses. Frequently, the stigma is internalized leading people to isolate themselves due to fear of disclosure, rejection, negative impact on their family, less favorable marriage prospects etc.

The above has caused leprosy to have a frightening image in history and human memory; one of mutilation, disability, rejection and social exclusion. The fear of having leprosy is often caused by the wrong perceptions regarding heredity, contagiousness, curability and mutilating. New preventive measures, effective treatment and interventions aimed at reducing stigma and enhancing social inclusion of those affected and within the community (i.e. rehabilitation) are hoped to contribute to a more positive image of leprosy and to its eventual elimination. 

Current leprosy situation
Global leprosy update, 2015: time for action, accountability and inclusion. Wkly Epidemiol Rec. 2016 Sep 2;91(35):405-20. English, French.

Towards elimination

Early detection and complete treatment with MDT are the main principles to leprosy control. In the mid 1980s, multidrug therapy (MDT) was introduced to leprosy programmes which has resulted in a significant reduction in the prevalence of the disease from 5.4 million at that time to a few hundred thousand currently. In 1991, the World Health Assembly called for the global elimination of leprosy as a public health problem by the year 2000. This was indeed achieved at a global level, and subsequently at a national level by most countries in 2005. The 5-year global leprosy strategies since then have focused on the reduction of disease burden measured in terms of new cases with visible deformities or grade-2 disabilities.