Mycobacterium ulcerans, the agent of Buruli/Bairnsdale ulcer, causes severe destructive lesions of skin and soft tissue, resulting in significant morbidity and often long-term disability. This disease has been reported in 33 countries across Africa, Americas, Asia and Western Pacific, including 340 notified cases in Victoria in 2018. It is a major issue around the Port Philip Bay Area where cases have spread rapidly (415% increase over 5 years), necessitating urgent research on treatment and prevention. Besides spreading to new geographical areas, the epidemic is also worsening in terms of case numbers as well as severity.
The environmental reservoir and the mode of transmission to humans are unknown, and there are no proven vaccines, prophylactic therapies or established animal models. Treatment is mostly through strong antibiotics, raising the likelihood of AMR (antimicrobial resistance); surgery is a mainstay of treatment, especially when antibiotics are not tolerated by the patient. This paper discusses ongoing collaboration between the CSIRO (Animal Services, Bacteriology and Dangerous Pathogens Teams; and Manufacturing and Werribee sites), Deakin University (Michelle Harvey Group) and Barwon Health (Daniel O’Brien Laboratory) on three related areas.
Firstly, we are exploring the use maggots of the common green bottle fly (Lucilia sericata) and other blowfly species for the debridement of wounds, as a less invasive and cheaper treatment which avoids hospitalisation and reduces AMR risk. Secondly, we are developing and validating suitable ex vivo and in vivo models to demonstrate the safety, efficacy and cost-effectiveness of maggot debridement therapy for Buruli ulcer. Finally, we are exploring the use of this in vivo model to evaluate the doses and duration of antibiotics required to achieve shortened treatment regimens and effective chemoprophylaxis -- the latter to prevent the development of secondary cases and to give health authorities and communities the first opportunity to control the disease incidence. Through these joint efforts, we hope to improve patient outcomes, as well as reduce (a) time to recovery; (b) estimated 6.5% risk of another family member developing the disease, and (c) burden on the Australian health system.