Recent changes in leprosy control

Abstract

The implementation of the secondary prevention strategy for leprosy control based on dapsone monotherapy had to face many difficulties. The main global results obtained during the period of the dapsone monotherapy approach may be summarized as follows: Worldwide. More than 5 million leprosy cases out of an estimated total of about 10 million existing cases are now under treatmeant. It can be estimated that from 1 to 1 1/2 million leprosy patients have been released from control during the last decade. Under favourable circumstances reductions of prevalence of 80% were achieved in a few countries or areas. The shortcomings of dapsone monotherapy have been increasingly realized over the last 15 years. A new approach to secondary prevention of leprosy through multidrug therapy of all cases has been recently recommended by WHO. The contribution of the THELEP Scientif Working Group to the development of the newly recommended regimens has been essential, clearly demonstrating transfer of the results of research to control efforts. For the first time the results of worldwide research efforts, stimulated and coordinated at the global level, have been translated into important changes in the strategy for leprosy control. However, in the long term, primary prevention methods, the most important being an effective vaccine, are an essential need in an effective strategy for leprosy control. In addition, immunological tools which would allow the identification of individuals at high risk of developing lepromatous leprosy will be of great help. In any case, it is unlikely that conclusions on the efficacy of a vaccine will be available within the next decade, or that new potent drugs can be developed. Therefore, for the years to come, and despite the shortcomings and limitations of the secondary prevention approach, the implementation of effective chemotherapeutic regimens based on combinations of bactericidal drugs is a must if we do not want the leprosy problem to become unmanageable and the gains made so far to be lost. Consequently, in the WHO leprosy programme for the next quinquennium top priority has been given to the implementation of multidrug therapy.