Relapses in leprosy patients after release from dapsone monotherapy; experience in the leprosy control program of the all Africa Leprosy and Rehabilitation Training Center (ALERT) in Ethiopia

Abstract

Before implementation of multidrug therapy (MDT), leprosy patients who were clinically inactive, skin-smear negative and had been treated with dapsone monotherapy for at least 5 years (paucibacillary patients) or for at least 10 years (multibacillary patients) were released from treatment. An analysis was made of self-reporting relapses in 1081 paucibacillary (PB) patients and 1123 multibacillary (MB) patients who had been released in Addis Ababa and two rural districts of the leprosy control program of the All Africa Leprosy and Rehabilitation Training Center (ALERT). During an average period of 6.6 years after stopping dapsone, 44 relapses were diagnosed among the PB patients and 148 relapses among the MB patients. The overall relapse rate was 4.1% or 7.2 per 1000 patient-years after release from treatment for PB patients and 13.2% and 24.8, respectively, for MB patients. The annual relapse rate in PB patients did not differ significantly from year to year. However the relapse rate for MB patients was significantly lower during the fifth to seventh years after stopping treatment compared with the first 4 years. Based on clinical findings there was a strong suspicion of relapse with dapsone-resistant bacilli in 40.4% of MB relapses. It is concluded that the relapse rate for PB patients is acceptable. However, the relapse rate for MB patients is considered too high. It is strongly recommended to administer to all MB patients, including those who have been on long-term treatment with dapsone and have become clinically and bacteriologically inactive, a 2-year course of MDT.