Since 1998 the recommended duration of treatment for multi- bacillary (MB) leprosy cases has been 12 months. Further shortening the duration of multi-drug therapy (MDT) for MB cases has been proposed, but evidence regarding long term outcomes is still needed. Disability outcomes are as important for the affected individual as the bacteriological response.

Newly diagnosed MB leprosy cases were recruited from 2 NGO projects in Bangladesh for treatment with 6m MB-MDT, and followed up for 10 years from diagnosis. Their outcomes were compared with those in a similar annual cohort of MB cases from the same projects who were diagnosed during the previous year, treated with 12m MB-MDT, and followed up in the same way.

Over a 10 year period there were no differences in outcomes between the 6m MB-MDT group and the control group who received 12m MB-MDT in regard to WHO disability grade or degree of nerve function impairment (NFI). The proportion of subjects ever needing steroids for reaction/neuritis did not differ between regimens. Mean duration of steroid therapy was longer in the 12m group. Only one relapse was diagnosed in 10 years of follow-up. This occurred at 9 years follow up, from a patient in the 6m treatment group.

In 2 cohorts of leprosy affected people who were actively followed up, the level of disability and the rate of relapse at 10 years after diagnosis was not significantly different between those receiving either 6m or 12m MB-MDT.