A Review of the Efficacy, Safety, and Feasibility of Rifamycin-Based Post-Exposure Chemoprophylaxis for Leprosy

In 2021, the World Health Organization (WHO) recommended scaling up leprosy prevention activities, including chemoprophylaxis, as one of the pillars of their 'Towards Zero Leprosy' strategy. This recommendation was primarily based on a 57% overall reduction in leprosy incidence among contacts who received chemoprophylaxis in the COLEP study conducted in Bangladesh. Since this landmark study, further research on the efficacy, feasibility, and implementation of leprosy chemoprophylaxis has been conducted. Additionally, concerns have been raised regarding the strength of evidence supporting the overall benefit of chemoprophylaxis and the potential for propagation of drug resistance in M. leprae strains. This literature review presents the current evidence for the efficacy and safety of rifamycin-based chemoprophylaxis in preventing clinical disease, and the feasibility of implementing chemoprophylaxis programmes. Post-exposure prophylaxis (PEP) has a reported efficacy of 45-80%, depending on the degree of case contact, the classification of the index case, the selected chemoprophylaxis regimen, the geographical setting, childhood BCG coverage and the implementation approach. As an intervention, it appears to be feasible, cost-effective, and acceptable to patients, contacts, and healthcare staff, with minimal harm. Implementation strategies need to be tailored to specific epidemiological and sociocultural settings for maximal benefit. Further research is required to optimise PEP regimens and strategies in various epidemiological settings and to assess the impact of these programmes on the susceptibility profile of local M. leprae strains.