The recent introduction of diaminodiphenylsulfone (DDS) and the thiosemicarbazones represents a significant contribution in the treatment of leprosy. The efficacy of DDS has been confirmed by a number of well-controlled observations (1, 2, 4, 5, 8, 10, 11). The effectiveness of thiosemicarbazone still remains to be evaluated (3, 7, 9, 12, 13, 14). For both drugs, the periods of observation have...