Fixed-duration multidrug therapy in multibacillary leprosy

Six-hundred-fifty-seven active multibacillary (MB) leprosy patients were put on fixed-duration multidrug therapy (FD-MDT) between 1985 and 1992 (190 had had no and 235 had had previous treatment with dapsone) and were followed for 5 years after therapy. Two relapses occurred during year 5 of surveillance and both had received dapsone prior to chemotherapy, giving an overall relapse rate of 0.08/100 person-years (py). Excluding the two relapses, 99.4% of the MB patients converted to smear negativity at year 6 after a regular course of FD-MDT. The relapse rate for 35 MB patients with an initial bacterial index (BI) of > 4 with 5 years of surveillance was 0.24/100 py. Reactions occurred more frequently during the first 6 months of MDT, decreasing gradually thereafter, and reaching 0 in year 4 of surveillance. The deformity rate at intake was 22.7% and only 1.8% of MB patients developed new deformities or an increased grade in deformity during therapy.

Risk of relapse in leprosy after fixed-duration multidrug therapy

Between 1986 and 1995, 8307 leprosy patients have completed fixed-duration multidrug therapy (FD-MDT) and were followed annually for possible relapse. The mean relapse rate for multibacillary (MB) leprosy is 0.15/1000 person-years (py) and for paucibacillary (PB) 0.55/1000 py. There is no difference in the relapse rates between patients with or without chemotherapy before FD-MDT. In MB patients, the five relapses occurred between 4 and 7 years; in PB patients, five relapses occurred at 4-5 years after FD-MDT. Six additional PB relapses self-reported 1-4 years after the 5-year surveillance period and were not included in the relapse rates. Most PB patients relapsed into MB due to wrong classification and insufficient therapy. For the known 62 irregular MB patients the cumulative relapse rate is 6.5%.