Increased Severity and Spread of Mycobacterium ulcerans, Southeastern Australia

Abstract

Reported cases of Mycobacterium ulcerans disease (Buruli ulcer) have been increasing in southeastern Australia and spreading into new geographic areas. We analyzed 426 cases of M. ulcerans disease during January 1998-May 2017 in the established disease-endemic region of the Bellarine Peninsula and the emerging endemic region of the Mornington Peninsula. A total of 20.4% of cases-patients had severe disease. Over time, there has been an increase in the number of cases managed per year and the proportion associated with severe disease. Risk factors associated with severe disease included age, time period (range of years of diagnosis), and location of lesions over a joint. We highlight the changing epidemiology and pathogenicity of M. ulcerans disease in Australia. Further research, including genomic studies of emergent strains with increased pathogenicity, are urgently needed to improve the understanding of disease to facilitate implementation of effective public health measures to halt its spread.

Keywords: Australia; Buruli ulcer; Mycobacteria ulcerans; Mycobacteria ulcerans disease; bacteria; severe disease; severity; spread; tuberculosis and other mycobacteria; zoonoses.

Figure 1

Locations (circles) of 426 cases of Mycobacterium ulcerans disease in Bellarine and Mornington Peninsulas, Barwon Health Cohort, Geelong, Victoria, Australia, January 1998–May 2017. Size of circles indicates number of cases, given in parentheses. Box in inset shows study region in southeastern Australia.

Figure 2

Proportion of severe and nonsevere cases of Mycobacterium ulcerans disease, Barwon Health Cohort, Geelong, Victoria, Australia, January 1998–May 2017.