Understanding risk factors is key to defining the source and transmission route of Mycobacterium ulcerans
Mycobacterium ulcerans causes an infectious disease known internationally as Buruli ulcer, and also as Bairnsdale ulcer or Daintree ulcer in Australia. It causes severe destructive lesions of skin and soft tissue, resulting in significant morbidity, in attributable mortality and often in long term disability and cosmetic deformity.1 All age groups, including young children, are affected, and the emotional and psychological impact on patients and their carers is substantial (Box 1). Although treatment effectiveness has improved in recent years, with cure rates approaching 100% using combination antibiotic regimens such as rifampicin and clarithromycin,2 these antibiotics are not covered by the Pharmaceutical Benefits Scheme for this condition and are, therefore, expensive to patients. Moreover, these antibiotics have severe side effects in up to one-quarter of patients,1 and many people also require reparative plastic surgery, sometimes with prolonged hospital admissions. The disease thus results in substantial costs, averaging $14 000 per patient including direct3 and indirect costs (eg, transport, lost productivity and dressings) — it had an estimated cost to Victoria in 2016 of $2 548 000 (Paul Mwebaze, Research Scientist, Adaptive Urban and Social Systems, Land and Water, CSIRO, Australia, personal communication, June 2017).
- 1. O’Brien DP, Friedman ND, Cowan R, et al. Mycobacterium ulcerans in the elderly: more severe disease and suboptimal outcomes. PLoS Negl Trop Dis 2015; 9: e0004253.
- 2. Friedman ND, Athan E, Walton AL, O’Brien DP. Increasing experience with primary oral medical therapy for Mycobacterium ulcerans disease in an Australian cohort. Antimicrob Agents Chemother 2016; 60: 2692-2695.
- 3. Pak J, O’Brien DP, Quek TY, Athan E. Treatment costs of Mycobacterium ulcerans in the antibiotic era. Int Health 2012; 4: 123-127.
- 4. World Health Organization. Buruli ulcer — number of new cases of Buruli ulcer reported: 2016 [website]. http://apps.who.int/neglected_diseases/ntddata/buruli/buruli.html (viewed Nov 2017).
- 5. Steffen CM, Freeborn H. Mycobacterium ulcerans in the Daintree 2009–2015 and the mini-epidemic of 2011. ANZ J Surg 2016.
- 6. Centers for Disease Control and Prevention. Lesson 6: investigating an outbreak [website]. Atlanta: CDC; 2016. https://www.cdc.gov/ophss/csels/dsepd/ss1978/lesson6/section2.html (viewed Nov 2017).
- 7. Tai A, Athan E, Friedman ND, et al. Increased severity and spread of Mycobacterium ulcerans, southeastern Australia. Emerg Infect Dis 2018. doi:10.3201/eid2401.171070. [Epub ahead of print].
- 8. Williamson HR, Benbow ME, Nguyen KD, et al. Distribution of Mycobacterium ulcerans in Buruli ulcer endemic and non-endemic aquatic sites in Ghana. PLoS Negl Trop Dis 2008; 2: e205.
- 9. Veitch MG, Johnson PD, Flood PE, et al. A large localized outbreak of Mycobacterium ulcerans infection on a temperate southern Australian island. Epidemiol Infect 1997; 119: 313-318.
- 10. Quek TYJ, Athan E, Henry MJ, et al. Risk factors for Mycobacterium ulcerans infection, southeastern Australia. Emerg Infect Dis 2007; 13: 1661-1666.
- 11. Portaels F, Elsen P, Guimaraes-Peres A, et al. Insects in the transmission of Mycobacterium ulcerans infection. Lancet 1999; 353: 986.
- 12. Wallace JR, Mangas KM, Porter JL, et al. Mycobacterium ulcerans low infectious dose and mechanical transmission support insect bites and puncturing injuries in the spread of Buruli ulcer. PLoS Negl Trop Dis 2017; 11: e0005553.
- 13. Fyfe JAM, Lavender CJ, Handasyde KA, et al. A major role for mammals in the ecology of Mycobacterium ulcerans. PLoS Negl Trop Dis 2010; 4: e791.
- 14. Yerramilli A, Tay EL, Stewardson AJ, et al. The location of Australian Buruli ulcer lesions — implications for unravelling disease transmission. PLoS Negl Trop Dis 2017; 11: e0005800.
- 15. O’Brien DP, Wynne JW, Buultjens AH, et al. Exposure risk for infection and lack of human-to-human transmission of Mycobacterium ulcerans disease, Australia. Emerg Infect Dis 2017; 23: 837-840.
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