Current challenges in leprosy research

Leprosy is an infectious disease caused by Mycobacterium leprae; it is uncommon but widespread globally and remains an important cause of peripheral neuropathy, especially in poor communities. An important reason to pay continued attention to leprosy is that, in contrast to many more common causes of disability, the impairments caused by leprosy are preventable through quite simple interventions, if identified early enough. In addition, it is well recognized that the stigma and psychosocial problems associated with leprosy cause immense suffering that is not easily measured. There are many areas of current interest in leprosy research, so this article will focus on areas of more immediate operational importance for leprosy control. The neglected tropical diseases (NTDs), of which leprosy is one, are now receiving attention on two fronts. First, as infectious diseases, innovative ways to reduce transmission to new hosts and, thus, reduce the future burden of disease in populations at risk are being developed. For several NTDs this can be done through annual mass drug administration (MDA); in leprosy, there are encouraging new developments in the prevention of transmission through chemoprophylaxis, which need further research, as outlined below. The second area in which further work is needed for many NTDs is morbidity management. Many NTDs cause chronic illness and disability; while interruption of transmission will help future generations, new ways to reduce the suffering of those already infected should also be promoted. Disability prevention has been an important area of research in leprosy and other conditions for many years, but there has been little cross-fertilization of ideas across diseases until recently. The challenge now is to apply the lessons learned to a whole range of diseases in an integrated manner, and to disseminate this knowledge and expertise at the community level.