Increasing experience with primary oral medical therapy for mycobacterium ulcerans disease in an Australian cohort

Buruli ulcer (BU) is a necrotizing infection of subcutaneous tissue that is caused by Mycobacterium ulcerans and is responsible for disfiguring skin lesions. The disease is endemic to specific geographic regions in the state of Victoria in southeastern Australia. Growing evidence of the effectiveness of antibiotic therapy for M. ulcerans disease has evolved our practice to the use of primarily oral medical therapy. An observational cohort study was performed on all confirmed M. ulcerans cases treated with primary rifampin-based medical therapy at Barwon Health between October 2010 and December 2014 and receiving 12 months of follow-up. One hundred thirty-two patients were managed with primary medical therapy. The median age of patients was 49 years, and nearly 10% had diabetes mellitus. Lesions were ulcerative in 83.3% of patients and at WHO stage 1 in 78.8% of patients. The median duration of therapy was 56 days, with 22 patients (16.7%) completing fewer than 56 days of antimicrobial treatment. Antibiotic-associated complications requiring cessation of one or more antibiotics occurred in 21 (15.9%) patients. Limited surgical debridement was performed on 30 of these medically managed patients (22.7%). Cure was achieved, with healing within 12 months, in 131 of 132 patients (99.2%), and cosmetic outcomes were excellent. Primary rifampin-based oral medical therapy for M. ulcerans disease, combined with either clarithromycin or a fluoroquinolone, has an excellent rate of cure and an acceptable toxicity profile in Australian patients. We advocate for further research to determine the optimal and safest minimum duration of medical therapy for BU.