Mycobacterium ulcerans Population Genomics To Inform on the Spread of Buruli Ulcer across Central Africa.

Buruli ulcer is a neglected tropical disease of skin and subcutaneous tissue caused by infection with the pathogen Mycobacterium ulcerans Many critical issues for disease control, such as understanding the mode of transmission and identifying source reservoirs of M. ulcerans, are still largely unknown. Here, we used genomics to reconstruct in detail the evolutionary trajectory and dynamics of M. ulcerans populations at a central African scale and at smaller geographical village scales. Whole-genome sequencing (WGS) data were analyzed from 179 M. ulcerans strains isolated from all Buruli ulcer foci in the Democratic Republic of the Congo, The Republic of Congo, and Angola that have ever yielded positive M. ulcerans cultures. We used both temporal associations and the study of the mycobacterial demographic history to estimate the contribution of humans as a reservoir in Buruli ulcer transmission. Our phylogeographic analysis revealed one almost exclusively predominant sublineage of M. ulcerans that arose in Central Africa and proliferated in its different regions of endemicity during the Age of Discovery. We observed how the best sampled endemic hot spot, the Songololo territory, became an area of endemicity while the region was being colonized by Belgium (1880s). We furthermore identified temporal parallels between the observed past population fluxes of M. ulcerans from the Songololo territory and the timing of health policy changes toward control of the Buruli ulcer epidemic in that region. These findings suggest that an intervention based on detecting and treating human cases in an area of endemicity might be sufficient to break disease transmission chains, irrespective of other reservoirs of the bacterium.IMPORTANCE Buruli ulcer is a destructive skin and soft tissue infection caused by Mycobacterium ulcerans The disease is characterized by progressive skin ulceration, which can lead to permanent disfigurement and long-term disability. Currently, the major hurdles facing disease control are incomplete understandings of both the mode of transmission and environmental reservoirs of M. ulcerans As decades of spasmodic environmental sampling surveys have not brought us much closer to overcoming these hurdles, the Buruli ulcer research community has recently switched to using comparative genomics. The significance of our research is in how we used both temporal associations and the study of the mycobacterial demographic history to estimate the contribution of humans as a reservoir in Buruli ulcer transmission. Our approach shows that it might be possible to use bacterial population genomics to assess the impact of health interventions, providing valuable feedback for managers of disease control programs in areas where health surveillance infrastructure is poor.

Insertion sequence element single nucleotide polymorphism typing provides insights into the population structure and evolution of Mycobacterium ulcerans across Africa.

Buruli ulcer is an indolent, slowly progressing necrotizing disease of the skin caused by infection with Mycobacterium ulcerans. In the present study, we applied a redesigned technique to a vast panel of M. ulcerans disease isolates and clinical samples originating from multiple African disease foci in order to (i) gain fundamental insights into the population structure and evolutionary history of the pathogen and (ii) disentangle the phylogeographic relationships within the genetically conserved cluster of African M. ulcerans. Our analyses identified 23 different African insertion sequence element single nucleotide polymorphism (ISE-SNP) types that dominate in different areas where Buruli ulcer is endemic. These ISE-SNP types appear to be the initial stages of clonal diversification from a common, possibly ancestral ISE-SNP type. ISE-SNP types were found unevenly distributed over the greater West African hydrological drainage basins. Our findings suggest that geographical barriers bordering the basins to some extent prevented bacterial gene flow between basins and that this resulted in independent focal transmission clusters associated with the hydrological drainage areas. Different phylogenetic methods yielded two well-supported sister clades within the African ISE-SNP types. The ISE-SNP types from the "pan-African clade" were found to be widespread throughout Africa, while the ISE-SNP types of the "Gabonese/Cameroonian clade" were much rarer and found in a more restricted area, which suggested that the latter clade evolved more recently. Additionally, the Gabonese/Cameroonian clade was found to form a strongly supported monophyletic group with Papua New Guinean ISE-SNP type 8, which is unrelated to other Southeast Asian ISE-SNP types.

Response to treatment in a prospective cohort of patients with large ulcerated lesions suspected to be Buruli Ulcer (Mycobacterium ulcerans disease).

BACKGROUND: The World Health Organization (WHO) advises treatment of Mycobacterium ulcerans disease, also called "Buruli ulcer" (BU), with a combination of the antibiotics rifampicin and streptomycin (R+S), whether followed by surgery or not. In endemic areas, a clinical case definition is recommended. We evaluated the effectiveness of this strategy in a series of patients with large ulcers of > or =10 cm in longest diameter in a rural health zone of the Democratic Republic of Congo (DRC). METHODS: A cohort of 92 patients with large ulcerated lesions suspected to be BU was enrolled between October 2006 and September 2007 and treated according to WHO recommendations. The following microbiologic data were obtained: Ziehl-Neelsen (ZN) stained smear, culture and PCR. Histopathology was performed on a sub-sample. Directly observed treatment with R+S was administered daily for 12 weeks and surgery was performed after 4 weeks. Patients were followed up for two years after treatment. FINDINGS: Out of 92 treated patients, 61 tested positive for M. ulcerans by PCR. PCR negative patients had better clinical improvement than PCR positive patients after 4 weeks of antibiotics (54.8% versus 14.8%). For PCR positive patients, the outcome after 4 weeks of antibiotic treatment was related to the ZN positivity at the start. Deterioration of the ulcers was observed in 87.8% (36/41) of the ZN positive and in 12.2% (5/41) of the ZN negative patients. Deterioration due to paradoxical reaction seemed unlikely. After surgery and an additional 8 weeks of antibiotics, 98.4% of PCR positive patients and 83.3% of PCR negative patients were considered cured. The overall recurrence rate was very low (1.1%). INTERPRETATION: Positive predictive value of the WHO clinical case definition was low. Low relapse rate confirms the efficacy of antibiotics. However, the need for and the best time for surgery for large Buruli ulcers requires clarification. We recommend confirmation by ZN stain at the rural health centers, since surgical intervention without delay may be necessary on the ZN positive cases to avoid progression of the disease. PCR negative patients were most likely not BU cases. Correct diagnosis and specific management of these non-BU ulcers cases are urgently needed.

Therapeutic itineraries of patients with ulcerated forms of Mycobacterium ulcerans (Buruli ulcer) disease in a rural health zone in the Democratic Republic of Congo.

OBJECTIVE: To describe lay perceptions of the ulcerated forms of Mycobacterium ulcerans, commonly called Buruli ulcer (BU), and therapeutic itineraries of BU patients in a rural area of the Democratic Republic of Congo. METHODS: Qualitative research consisting of semi-structured interviews of 19 patients with clinical signs of BU and 12 in-depth interviews of confirmed cases allowing for a detailed reconstruction of the itineraries followed. RESULTS: The first symptoms of BU are perceived as mild. The perceived seriousness of the disease increases as the ulceration persists, increases in size or results in complications. Knowledge about the biomedical aetiology of the disease is scarce; it is commonly believed to be due to witches' attacks or bad fate. Four therapeutic paths are taken: self-medication, traditional therapy, the church and the health centre. However lay perception, recourse to traditional treatments and self-medication only partially explain the long delays in diagnosis (on average 6 months); the main problem lies with health providers, particularly the lack of proper diagnostic capability. CONCLUSIONS: Diagnostic capabilities at health centre level need to be strengthened through training and supervision. Engaging with the population and the traditional healers would render health promotion messages on BU more relevant and culturally acceptable.

New foci of Buruli ulcer, Angola and Democratic Republic of Congo.

We report 3 patients with laboratory-confirmed Buruli ulcer in Kafufu/Luremo, Angola, and Kasongo-Lunda, Democratic Republic of Congo. These villages are near the Kwango/Cuango River, which flows through both countries. Further investigation of artisanal alluvial mining as a risk factor for Buruli ulcer is recommended.

[Streptomycin injections for the treatment of Mycobacterium ulcerans (Buruli ulcer) in a rural health zone in the Democratic Republic of the Congo]. / Les injections répétées de streptomycine dans le traitement de l'infection à Mycobacterium ulcerans (ulcère de Buruli): à propos d'une enquête dans une zone de santé rurale en République démocratique du Congo.

This paper presents the results of a study conducted in a rural zone of the Democratic Republic of the Congo (DRC) in two groups of 14 patients with Mycobacterium ulcerans infection, also known as Buruli ulcer. The first group underwent the treatment recommended by the World Health Organization (WHO): rifampicin and streptomycin, combined with surgery. They were surveyed after treatment, while the control group was awaiting the onset of treatment. Most patients in this study were children. The patients in first group found the treatment acceptable, although the patients in both groups preferred to avoid surgery. Patients' knowledge about the effects of streptomycin was rather poor: 58% in the first group and 28% in the second had inadequate knowledge. In the first group, 70% found the injections acceptable, and in the second group, 57%. Most patients would prefer oral administration of a different but equally effective drug rather than injected streptomycin.

[The contribution of skin autograft in open air in the treatment of the Buruli ulcer]. / Apport de l'autogreffe cutanée à l'air libre dans le traitement de l'ulcère de Buruli.

The Buruli ulcer (BU) rages in a lot of tropical and subtropical countries. In Democratic Republic of Congo, some BU cases were reported between the 50s and 70s. This disease offers resistance to the usual chemotherapy. The only alternative for the treatment remains the surgical one (trimming, wound dressing, graft). The overarching aim of this study, conducted in the province of Lower Congo, is to put forward a surgical therapeutic approach adapted to the precarious conditions met on the ground in our rural areas. The evidence of a Mycobacterium ulcerans infection has been bacteriological and histopathological. The slight skin autograft or "of Davis", in open air or with dressing was performed in 37 patients. After three months this skin autograft in open air has experienced 78.5% of complete healing against 70% for the skin autograft with dressing. The exposure of skin graftings to open air favors an hyperoxygenation which also fights against the Mycobacterium ulcerans, for this latter develops better in an hypoxical area.

[Knowledge-attitudes-practices survey of the Songololo population (D.R. Congo) about Buruli ulcers]. / Enquête connaissances-attitudes-pratiques (CAP) de la population de Songololo (R.D. Congo) sur l'ulcère de Buruli.

The Buruli ulcer (B. U.) is rampant in many tropical and subtropical countries. In D.R. of Congo, some cases of Buruli ulcer have been reported between 1950 and 1970 in the endemic focus of Songololo-Kimpese (Lower-Congo Province). The objective of this study was to provide some anthropological knowledge for better treatment of this pathology; to confirm the presence of Buruli ulcer in that focus and to describe general caracteristics of the subjects. This disease looked upon as "mbasu" (in the Ndibu population in majority in that focus) is experienced as a malediction, or punishment. The success of a program to fight against Buruli ulcer lies on health education which takes into account the representation systems of diseases.

[Buruli ulcer in Angolese refugees in the Kimpese area, Lower Congo, D.R. Congo]. / L'ulcère de Buruli chez les réfugiés angolais des sites de Kimpesse, Bas-Congo, RD Congo.

Many epidemiological studies on Buruli ulcer have established the endemic zones in the Congolese Democratic Republic. But the situation about the areas where the refugees are located in high endemicity zones has not yet been studied. The present study describes the presence of the Mycobacterium ulcerans infection in the angolese refugee populationat Kimpese. The data obtained reveal that 50% of patients in the region are angolese refugees. All patients were infected two years before their insertion. The group most affected are children under 15 with a predominance of masculine patients. The legs were the most affected. The most frequent form is the ulcerative form.