Hansen’s disease or leprosy was previously present in most parts of the world. Now it is a problem in regions of extreme poverty. The number of registered cases is falling: 5.37 million in 1985 ® 3.1 million in 1992 and approximately 1.8 million in 2000. There are probably as many patients who have not yet been discovered. The number of severe infections is clearly decreasing. In 1996 only 70,000 new multibacillary patients were found. It is hoped to bring the general incidence of the infection below 1/10,000 in the near future. By 1999, 80% of all leprosy cases were occurring in 6 countries: India, Brazil, Bangladesh, Indonesia, Burma and Nigeria. HIV-infected patients usually die of infections caused by faster growing bacteria (e.g. tuberculosis), and not from the slow-growing Mycobacterium leprae. The AIDS epidemic has therefore had little effect on the incidence of leprosy. The illness is characterised by skin and nerve lesions. This leads to neural dysfunction, which together with progressive tissue destruction causes mutilation. Resistance to dapsone became a significant problem around 1980. This is why combination therapy has been used since that time.