Spontaneous healing of Mycobacterium ulcerans disease in Australian patients.

BACKGROUND: Mycobacterium ulcerans causes necrotising infections of skin and soft tissue mediated by the polyketide exotoxin mycolactone that causes cell apoptosis and immune suppression. It has been postulated that infection can be eradicated before the development of clinical lesions but spontaneous resolution of clinical lesions has been rarely described. METHODOLOGY/PRINCIPAL FINDINGS: We report a case series of five Australian patients who achieved healing of small M. ulcerans lesions without antibiotics or surgery. The median age of patients was 47 years (IQR 30-68 years) and all patients had small ulcerative lesions (median size 144mm2, IQR 121-324mm2). The median duration of symptoms prior to diagnosis was 90 days (IQR 90-100 days) and the median time to heal from diagnosis without treatment was 68 days (IQR 63-105 days). No patients recurred after a median follow-up of 16.6 months (IQR 16.6-17.9 months) from the development of symptoms and no patients suffered long-term disability from the disease. CONCLUSIONS: We have shown that healing without specific treatment can occur for small ulcerated M. ulcerans lesions suggesting that in selected cases a robust immune response alone can cure lesions. Further research is required to determine what lesion and host factors are associated with spontaneous healing, and whether observation alone is an effective and safe form of management for selected small M. ulcerans lesions.

Life cycle assessment of municipal solid waste management scenarios on the small island of Mauritius.

The aim of this study was to use the life cycle assessment tool to assess, from an environmental point of view, the different possible municipal solid waste (MSW) management scenarios for the island of Mauritius. The scenarios include landfilling with energy recovery (S1), incineration with energy recovery (S2), composting, incineration and landfilling (S3) and finally composting, recycling, incineration and landfilling (S4). The MSW generated in 2010 was selected as the functional unit. Foreground data were collected through surveys and literature. Background data were obtained from ecoinvent data in SimaPro 8 libraries. The scenarios were compared both through the CML-IA baseline-midpoint method and the ReCiPe end-point method. From the midpoint method, the results obtained indicates that landfilling (S1) has the greatest impact in all the analyzed impact categories except ozone layer depletion and human toxicity, while incineration (S2) has the least impact on almost all the analyzed damage categories except in global warming potential and human toxicity. The collection and transportation of waste has a significant impact on the environment. From the end-point method, S4 reduces the damage impact categories on Human Health, Ecosystems and Resources due to the recycling process. S3 is not favorable due to the impact caused by the composting process. However, it is also very important to emphasize that for incineration, the best available technology with energy recovery shall be considered. It is recommended that S2 and S4 are considered for strategic planning.