Background: As the third most common mycobacterial infection in the world after tuberculosis and ... more Background: As the third most common mycobacterial infection in the world after tuberculosis and leprosy, Mycobacterium ulcerans is a major health and development problem that has become the focus of a World Health Organisation (WHO) initiative seeking to reduce the burden of this disease. The Daintree River catchment in north Queensland is an endemic focus for Mycobacterium ulcerans infection, known locally as the 'Daintree Ulcer'. The aim of this study is to analyse the changing pattern of the disease over the last 44 years in the region. Methods: The study is a descriptive review of all human cases where infection had been acquired in an endemic region of far north Queensland. Demographic information, lesion characteristics, management and outcomes were recorded in a database. Results: Over the period there were 92 cases of M. ulcerans infection. The average age was 41.7 years and 56.7% were male. There was distinct clustering of cases in several defined locations in the area. Most cases (90%) presented with ulcers, and all but three patients were treated surgically. Excision and skin grafting was more commonly used in the period between 1964-1988. Excision alone was the most common treatment used thereafter. Earlier recognition and smaller lesion size is thought to have contributed to the change in surgical practice. Conclusions: Ulcers caused by M. ulcerans infection are a distinct clinical entity in tropical North Queensland. Early recognition, diagnosis and prompt surgical intervention has minimised morbidity associated with this disease.
LESSONS FROM PRACTICE MYCOBACTERIUM ULCERANS is an environmental bacterium causing skin ulcers. A... more LESSONS FROM PRACTICE MYCOBACTERIUM ULCERANS is an environmental bacterium causing skin ulcers. An endemic area of M. ulcerans disease in temperate southeast Victoria, where the disease is known as "Bairnsdale ulcer", has been extensively studied, and continues to involve new geographic areas. 1 A less well known endemic area exists in tropical far north Queensland between Mossman and the Daintree River (Douglas Shire) (Box 1), where it is called "Daintree ulcer". 2 Our patient presented with diffuse limb swelling of acute onset without ulceration and associated with systemic symptoms, which is unusual for M. ulcerans disease in Australia; only two previous cases from far north Queensland have presented in this way. 2 Most patients in Australia initially note a papular lesion, which subsequently ulcerates after weeks to months without associated systemic symptoms. 3 The classic ulcer is painless, with a sharp, undermined edge and surrounding induration, indicating the extent of necrotic subcutaneous tissue. Histopathological examination of excised tissue from patients with M. ulcerans disease shows large numbers of extracellular mycobacteria, a poorly developed immune response and widespread necrosis of subcutaneous tissue, 4 which may be mediated by a recently described lipid toxin (mycolactone) produced by M. ulcerans. 5 The accepted treatment of M. ulcerans disease remains complete surgical excision of all necrotic tissue, often extending well beyond the visible margins of the ulcer, with MJA Vol 176
Mycobacterium ulcerans , the cause of Buruli ulcer, is an environmental mycobacterium with a dist... more Mycobacterium ulcerans , the cause of Buruli ulcer, is an environmental mycobacterium with a distinct geographic distribution. The reasons why only some individuals who are exposed to M. ulcerans develop ulcers are not known but are likely to reflect individual differences in the immune response to infections with this bacterium. In this study, we investigated cytokine profiles of peripheral blood mononuclear cells (PBMC) from 23 Buruli ulcer patients and 25 household contacts in a region of Australia where Buruli ulcer is endemic. The results showed that following stimulation with M. ulcerans or Mycobacterium bovis BCG, PBMC from Buruli ulcer patients mounted a Th2-type response, which was manifested by the production of mRNA for interleukin 4 (IL-4), IL-5, IL-6, and IL-10, whereas unaffected contacts responded mainly with the Th1 cytokines gamma interferon (IFN-γ) and IL-12. For example, mRNA for IL-4 was detected in 18 of 23 patients but in only 3 of 25 control subjects ( P < ...
Background: As the third most common mycobacterial infection in the world after tuberculosis and ... more Background: As the third most common mycobacterial infection in the world after tuberculosis and leprosy, Mycobacterium ulcerans is a major health and development problem that has become the focus of a World Health Organisation (WHO) initiative seeking to reduce the burden of this disease. The Daintree River catchment in north Queensland is an endemic focus for Mycobacterium ulcerans infection, known locally as the 'Daintree Ulcer'. The aim of this study is to analyse the changing pattern of the disease over the last 44 years in the region. Methods: The study is a descriptive review of all human cases where infection had been acquired in an endemic region of far north Queensland. Demographic information, lesion characteristics, management and outcomes were recorded in a database. Results: Over the period there were 92 cases of M. ulcerans infection. The average age was 41.7 years and 56.7% were male. There was distinct clustering of cases in several defined locations in the area. Most cases (90%) presented with ulcers, and all but three patients were treated surgically. Excision and skin grafting was more commonly used in the period between 1964-1988. Excision alone was the most common treatment used thereafter. Earlier recognition and smaller lesion size is thought to have contributed to the change in surgical practice. Conclusions: Ulcers caused by M. ulcerans infection are a distinct clinical entity in tropical North Queensland. Early recognition, diagnosis and prompt surgical intervention has minimised morbidity associated with this disease.
LESSONS FROM PRACTICE MYCOBACTERIUM ULCERANS is an environmental bacterium causing skin ulcers. A... more LESSONS FROM PRACTICE MYCOBACTERIUM ULCERANS is an environmental bacterium causing skin ulcers. An endemic area of M. ulcerans disease in temperate southeast Victoria, where the disease is known as "Bairnsdale ulcer", has been extensively studied, and continues to involve new geographic areas. 1 A less well known endemic area exists in tropical far north Queensland between Mossman and the Daintree River (Douglas Shire) (Box 1), where it is called "Daintree ulcer". 2 Our patient presented with diffuse limb swelling of acute onset without ulceration and associated with systemic symptoms, which is unusual for M. ulcerans disease in Australia; only two previous cases from far north Queensland have presented in this way. 2 Most patients in Australia initially note a papular lesion, which subsequently ulcerates after weeks to months without associated systemic symptoms. 3 The classic ulcer is painless, with a sharp, undermined edge and surrounding induration, indicating the extent of necrotic subcutaneous tissue. Histopathological examination of excised tissue from patients with M. ulcerans disease shows large numbers of extracellular mycobacteria, a poorly developed immune response and widespread necrosis of subcutaneous tissue, 4 which may be mediated by a recently described lipid toxin (mycolactone) produced by M. ulcerans. 5 The accepted treatment of M. ulcerans disease remains complete surgical excision of all necrotic tissue, often extending well beyond the visible margins of the ulcer, with MJA Vol 176
Mycobacterium ulcerans , the cause of Buruli ulcer, is an environmental mycobacterium with a dist... more Mycobacterium ulcerans , the cause of Buruli ulcer, is an environmental mycobacterium with a distinct geographic distribution. The reasons why only some individuals who are exposed to M. ulcerans develop ulcers are not known but are likely to reflect individual differences in the immune response to infections with this bacterium. In this study, we investigated cytokine profiles of peripheral blood mononuclear cells (PBMC) from 23 Buruli ulcer patients and 25 household contacts in a region of Australia where Buruli ulcer is endemic. The results showed that following stimulation with M. ulcerans or Mycobacterium bovis BCG, PBMC from Buruli ulcer patients mounted a Th2-type response, which was manifested by the production of mRNA for interleukin 4 (IL-4), IL-5, IL-6, and IL-10, whereas unaffected contacts responded mainly with the Th1 cytokines gamma interferon (IFN-γ) and IL-12. For example, mRNA for IL-4 was detected in 18 of 23 patients but in only 3 of 25 control subjects ( P < ...
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