Twenty five years follow up of MB leprosy patients retreated with a modified MDT regimen after a full course of dapsone mono-therapy.

BACKGROUND The relentless emergence of dapsone resistance amongst M. leprae threatened leprosy control programmes, and increased the relapse rate of patients cured with dapsone monotherapy. OBJECTIVE The study aimed to analyse the effect on the relapse rate of dapsone-cured multibacillary (MB) leprosy patients, of re-treatment, using a multidrug therapy (MDT) regimen which differed from the WHO recommended regimen. DESIGN 794 MB leprosy patients who had been released from treatment after dapsone monotherapy were selected, amongst them 657 were re-treated for 1 year using the modified multidrug therapy regimen (mMDT) including rifampicin, clofazimine and dapsone, and 137 patients were observed as control cases. RESULTS The regimen was well tolerated with good compliance: 620 patients completed re-treatment with mild side effects and a low incidence of leprosy reactions. There was a statistically significant difference between the relapse rates of re-treated and control groups (chi squaredf = 57.44, P < 0.001). Furthermore, the relapses in the re-treated group were significantly more likely to be later than those in the control group (t = 25.62, P < 0.001). CONCLUSIONS Re-treatment with this modified regimen is acceptable and can reduce the risk of early relapse in dapsone-cured patients. The problem of persisters causing late relapse is likely to remain.