A LARGE LOCALIZED OUTBREAK OF MYCOBACTERIUM-ULCERANS INFECTION ON A TEMPERATE SOUTHERN AUSTRALIAN ISLAND

Mycobacterium ulcerans, the organism which causes Buruli or Bairnsdale ulcer, has never been isolated in culture from an environmental sampl e. Most foci of infection are in tropical regions. The authors describ e the first 29 cases of M. ulcerans infection from a new focus on an i sland in temperate southern Australia, 1992-5. Cases were mostly elder ly, had predominantly distal limb lesions and were clustered in a smal l region in the eastern half of the main town on the island. The autho rs suspected that an irrigation system which lay in the midst of the c luster was a source of infection. Limitation of irrigation was associa ted with a dramatic reduction in the number of new cases. These findin gs support the hypothesis that M. ulcerans has an aquatic reservoir an d that persons may be infected directly or indirectly by mycobacteria disseminated locally by spray irrigation.