Mycobacterium ulcerans infection

Abstract

After tuberculosis and leprosy, Buruli-ulcer disease (caused by infection with Mycobacterium ulcerans) is the third most common mycobacterial disease in immunocompetent people. Countries in which the disease is endemic have been identified, predominantly in areas of tropical rain forest; the emergence of Buruli-ulcer disease in West African countries over the past decade has been dramatic. Current evidence suggests that the infection is transmitted through abraded skin or mild traumatic injuries after contact with contaminated water, soil, or vegetation; there is one unconfirmed preliminary report on possible transmission by insects. The clinical picture ranges from a painless nodule to large, undermined ulcerative lesions that heal spontaneously but slowly. Most patients are children. The disease is accompanied by remarkably few systemic symptoms, but occasionally secondary infections resulting in sepsis or tetanus cause severe systemic disease and death. Extensive scarring can lead to contractures of the limbs, blindness, and other adverse sequelae, which impose a substantial health and economic burden. Treatment is still primarily surgical, and includes excision, skin grafting, or both. Although BCG has a mild but significant protective effect, new vaccine developments directed at the toxins produced by M. ulcerans are warranted. In West Africa, affected populations are underprivileged, and the economic burden imposed by Buruli-ulcer disease is daunting. Combined efforts to improve treatment, prevention, control, and research strategies (overseen by the WHO and funded by international relief agencies) are urgently needed.

PIP: This paper focuses on Buruli-ulcer disease, the third most common mycobacterial disease among immunocompetent people. Buruli-ulcer disease is caused by an infection with Mycobacterium ulcerans, which belongs to the large group of environmental mycobacteria. It is endemic in many countries, usually in areas of tropical rain forest. Transmission of infection is through abraded skin or mild traumatic injuries after contact with contaminated water, soil, or vegetation. This disease mostly affects children which manifest from painless nodules to large, undermined ulcerative lesions that heals spontaneously but slowly. Buruli-ulcer disease is accompanied by few systemic symptoms, but occasionally secondary infections resulting in sepsis or tetanus cause severe systemic disease and death. However, extensive scarring can lead to contractures of the limbs, blindness, and other adverse complications. Management of the disease is still primarily surgical, and includes excision, skin grafting, or both. Although Bacillus Calmette-Guerin vaccine has mild but a significant protective effect, vaccine developments directed at the toxin produced by M. ulcerans are needed.