Epidemiology and disease burden of Buruli ulcer: a review

Buruli ulcer (BU) is a neglected tropical skin disease caused by Mycobacterium ulcerans. Infection foci occur mainly in remote, rural areas of Central and West Africa, but also in Australia and Papua New Guinea. In addition, infections caused by M. ulcerans strains of a different lineage are sporadically reported from scattered foci in Asia and the Americas. While in the past decade more than 42,000 BU cases have been reported worldwide, an assessment of the actual global disease burden is complicated by the remoteness of affected populations and a lack of data on the incidence of BU in a number of countries, from which cases have been historically reported. Moreover, as BU patients present with diverse clinical manifestations ranging from relatively unspecific nodules, plaques, or edema to necrotic, ulcerative lesions, differential diagnosis is manifold and thus clinical misclassification may occur. Since to date reservoirs and transmission pathways of M. ulcerans remain equivocal, early diagnosis and treatment of patients are key determinants to control the disease. Particularly in view of the apparent decline in BU incidence in regions of West Africa, awareness and knowledge of BU in endemic regions must be retained to ensure a continuous monitoring and control. An integrated approach for the control of tropical skin diseases should be considered to cope with this difficult task. This review article aims at providing an overview of the current global burden of BU and summarizes the state of knowledge on the various epidemiological aspects of this enigmatic disease.