Elimination of leprosy as a public health problem: progress and prospects.

Leprosy is still an important problem in about 80 countries of Asia, Africa and Latin America, some 2.4 million persons being estimated to have the disease in 1994. The WHO-recommended standard multidrug therapy (MDT) was introduced in the 1980s and has been shown to be effective in combating the disease. Experiences based on many thousands of patients treated with MDT over the past decade indicate extremely low relapse rates (cumulative relapse rates around 1%). By the end of 1993, some 5.6 million patients had been cured, and the global cumulative MDT coverage of registered patients had reached 89%. The number of registered cases fell from 5.4 million in 1985 to 1.7 million in 1994. The significant progress made in leprosy control enabled the World Health Assembly in 1991 to set a goal for eliminating leprosy as a public health problem by the year 2000. One important epidemiological factor is that leprosy is very unevenly distributed: 80% of the problem is confined to only five countries and 92% to just 25 countries. The elimination strategy envisages identifying and treating with MDT a total of about 5 million cases from 1994 to the year 2000. The cost of dealing with these cases has been estimated at US$ 420 million, including US$ 150 million for the drugs.