Low rate of relapse after twelve-dose multidrug therapy for hansen’s disease: A 20-year cohort study in a brazilian reference center

Abstract

The World Health Organization has raised concerns about the increasing number of Hansen disease (HD) relapses worldwide, especially in Brazil, India, and Indonesia that report the highest number of recurrent cases. Relapses are an indicator of MDT effectiveness and can reflect Mycobacterium leprae persistence or re-infection. Relapse is also a potential marker for the development or progression of disability. In this research, we studied a large cohort of persons affected by HD treated with full fixed-dose multibacillary (MB) multidrug therapy (MDT) followed for up to 20 years and observed that relapses are a rare event. We estimated the incidence density of relapse in a cohort of patients classified to receive MB regime (bacillary index (BI) > 0), diagnosed between September 1997 and June 2017, and treated with twelve-dose MB-MDT at a HD reference center in Rio de Janeiro, Brazil. We obtained the data from the data management system of the clinic routine service. We linked the selected cases to the dataset of relapses of the national HD data to confirm possible relapse cases diagnosed elsewhere. We diagnosed ten cases of relapse in a cohort of 713 patients followed-up for a mean of 12.1 years. This resulted in an incidence rate of 1.16 relapse cases per 1000 person-year (95% CI = 0.5915–2.076). The accumulated risk was 0.025 in 20 years. The very low risk observed in this cohort of twelve-dose-treated MB patients reinforces the success of the current MDT scheme. People affected by Hansen disease that have many skin patches or lumps receive twelve-dose multibacillary multidrug therapy. After the fixed-dose regime, they are released from treatment and are considered cured. However, some of these people may have a recurrence of skin lesions or peripheral nerve problems after several years. Clinicians, scientists, and the World Health Organization are concerned about this problem, known as relapse, which seems to be increasing in countries where Hansen disease is common, especially in Brazil, India, and Indonesia. It is important to demonstrate regular proof that the therapy remains effective to treat people affected by Hansen disease. In this study, we showed that the recurrence of signs and symptoms of Hansen disease after the twelve-dose multibacillary treatment is rare. These findings are good evidence of the success of the current multibacillary scheme.