Heterogeneity among Mycobacterium ulcerans isolates from Africa

Mycobacterium ulcerans causes Buruli ulcer, an ulcerative skin disease in tropical and subtropical areas. Despite restricted genetic diversity, mycobacterial interspersed repetitive unit-variable-number tandem repeat analysis on M. ulcerans revealed 3 genotypes from different African countries. It is the first time this typing method succeeded directly on patient samples

Urbanisation and women's health in Khayelitsha Part I. Demographic and socio-economic profile

Demographic and socio-economic data and information on migration patterns and urban/rural links was collected from 722 households in the formal housing area and the serviced and the unserviced site areas of Khayelitsha; 659 women and 61 men were interviewed. Thirty-eight per cent of the population were aged under 15 years and 77% under 35 years. There was a predominance of females in the 5 - 35-year age group. There was a mean of 4,9 persons per household, and 93,5% of sites contained 1 dwelling. Of the 659 female respondents, 7% had received no formal education, 39% had primary school education, and 54% had secondary school education. unemployment among women was 45%. Domestic service accounted for 66,2% of formal employment. Of all women 86% were unskilled, 71,9% had been born in a 'homeland', and 69,7% had migrated to an urban area before 1985. Ties to the rural areas were strong, particularly in the 'shack' areas. 'New arrivals' to an urban area were young, mostly unemployed, and lived in the worst environmental conditions. In the unserviced 'shack' areas, 47,5% of women had migrated to an urban area in the last 5 years. These are important target areas for a study of the health effects of urbanisation and for possible interventions. This study tends to confirm the 'quadruple' oppression of women in Khayelitsha, on the basis of race, social class and gender and as new arrivals in an urban environment

Urbanisation and women's health in Khayelitsha Part 11. Health status and use of health services

A study was conducted among women in Khayelitsha to determine the relationship between urbanisation, health status and use of health services; 722 households were visited, and 659 female respondents provided information on acute and chronic illness for the 3229 individuals who were members of their households. In addition, they provided information concerning their reproductive health, AIDS awareness, knowledge of cervical smears and use and knowledge of health services. Acute illness was reported for .4,3% of the study population, the commonest complaints being diarrhoea, abdominal pain and upper respiratory infections; 4,4% reported chronic illness, the commonest complaints being hypertension and tuberculosis; 16,2% of women reported gynaecological illness; 86% had of heard of AIDS (although their knowledge of transmission and prevention was poor); and 45% had heard of cervical smears. Patterns of illness and knowledge and use of health services vary in the different areas of residence of Khayelitsha. This appears to be related to urbanisation, age, and environmental and socio-economic factors

Radical palliative surgery: new limits to pursue

This case report describes the radical subtotal palliative resection of a massive recurrent desmoid tumor encompassing the abdomen, pelvis, and groin in a child who was 13 years old at the time of initial resection. Given the extensive distribution of the tumor en bloc resection, which is the standard treatment of desmoid tumors, would have meant performing a hemipelvectomy and repair of a large abdominal wall defect, likely with skin grafts and mesh. The patient’s personal goals however were to alleviate the pain and limited mobility that would allow her to re-attend high school and appear normal to her peers. Therefore, palliative surgery was pursued and currently the patient is 5 years out from her last surgery doing well. We believe that the option of surgical palliation in this case was warranted and should be an option for similar cases in the future

The Role of Vaccine Coverage within Social Networks in Cholera Vaccine Efficacy

Traditional vaccine trial methods have an underlying assumption that the effect of a vaccine is the same throughout the trial area. There are, however, many spatial and behavioral factors that alter the rates of contact among infectious and susceptible individuals and result in different efficacies across a population. We reanalyzed data from a field trial in Bangladesh to ascertain whether there is evidence of indirect protection from cholera vaccines when vaccination rates are high in an individual's social network.We analyzed the first year of surveillance data from a placebo-controlled trial of B subunit-killed whole-cell and killed whole-cell-only oral cholera vaccines in children and adult women in Bangladesh. We calculated whether there was an inverse trend for the relation between the level of vaccine coverage in an individual's social network and the incidence of cholera in individual vaccine recipients or placebo recipients after controlling for potential confounding variables.Using bari-level social network ties, we found incidence rates of cholera among placebo recipients were inversely related to levels of vaccine coverage (5.28 cases per 1000 in the lowest quintile vs 3.27 cases per 1000 in the highest quintile; p = 0.037 for trend). Receipt of vaccine by an individual and the level of vaccine coverage of the individual's social network were independently related to a reduced risk of cholera.Findings indicate that progressively higher levels of vaccine coverage in bari-level social networks can lead to increasing levels of indirect protection of non-vaccinated individuals and could also lead to progressively higher levels of total protection of vaccine recipients

Phase Change Material for Thermotherapy of Buruli Ulcer: A Prospective Observational Single Centre Proof-of-Principle Trial

Buruli ulcer is an infection of the subcutaneous tissue leading to chronic necrotizing skin ulcers. The causative pathogen, Mycobacterium ulcerans, grows best at 30°C–33°C and not above 37°C, and this property makes the application of heat a treatment option. We achieved a breakthrough in heat treatment of Buruli ulcer by employing the phase change material sodium acetate trihydrate as a heat application system for thermotherapy, which is widely used in commercial pocket heat pads. It is easy to apply, rechargeable in hot water, non-toxic and non-hazardous to the environment. Six laboratory reconfirmed patients with ulcerative Buruli lesions were included in the proof-of-principle study and treated for four to six weeks. In patients with small ulcers, wounds healed completely without further intervention. Patients with large defects had skin grafting after successful heat treatment. Heat treatment was not associated with marked increases in local inflammation or the development of ectopic lymphoid tissue. One and a half years after completion of treatment, all patients are relapse-free. The reusable phase change material–based heat application device appears perfectly suited for use in remote Buruli ulcer–endemic areas of countries with limited resources and infrastructure

Health Services for Buruli Ulcer Control: Lessons from a Field Study in Ghana

Buruli ulcer (BU), caused by Mycobacterium ulcerans infection, is a debilitating disease of the skin and underlying tissue which starts as a painless nodule, oedema or plaque and could develop into painful and massive ulcers if left untreated. Using a combination of quantitative and qualitative methods, the study assessed the effectiveness of the BUPaT programme to improve early detection and management of BU in an endemic area in Ghana. The results of the study showed extensive collaboration across all levels, (national, municipality and community), which contributed to strengthening the programme. Health staff were trained to manage all BU cases. School teachers, municipal environmental staff and community surveillance volunteers were trained to give the right health messages, screen for detection of early cases and refer for medical treatment. WHO-recommended antibiotics improved treatment and cure, particularly for early lesions, and prevented recurrences. Improving access to antibiotic treatment is critical for early case management. Health education is required to emphasise the effectiveness of treatment with antibiotics to reduce deformities and the importance of seeking medical treatment for all skin lesions. Further research is needed to explain the role of environmental factors in BU contagion

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.This study was supported by the Directorate-General for Development and Cooperation (DGDC), Brussels, Belgium, the European Commission (International Science and Technology Cooperation Development Program) (project no. INCO-CT-2005-051476-BURULICO), and by a grant from the Health Services of Fundacao Calouste Gulbenkian. K.K. was supported by a grant from DGDC. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Diagnosis of Human Visceral Pentastomiasis

Visceral pentastomiasis in humans is caused by the larval stages (nymphs) of the arthropod-related tongue worms Linguatula serrata, Armillifer armillatus, A. moniliformis, A. grandis, and Porocephalus crotali. The majority of cases has been reported from Africa, Malaysia, and the Middle East, where visceral pentastomiasis may be an incidental finding in autopsies, and less often from China and Latin America. In Europe and North America, the disease is only rarely encountered in immigrants and long-term travelers, and the parasitic lesions may be confused with malignancies, leading to a delay in the correct diagnosis. Since clinical symptoms are variable and serological tests are not readily available, the diagnosis often relies on histopathological examinations. This laboratory symposium focuses on the diagnosis of this unusual parasitic disease and presents its risk factors and epidemiology

LTC: a novel algorithm to improve the efficiency of contig assembly for physical mapping in complex genomes

<p>Abstract</p> <p>Background</p> <p>Physical maps are the substrate of genome sequencing and map-based cloning and their construction relies on the accurate assembly of BAC clones into large contigs that are then anchored to genetic maps with molecular markers. High Information Content Fingerprinting has become the method of choice for large and repetitive genomes such as those of maize, barley, and wheat. However, the high level of repeated DNA present in these genomes requires the application of very stringent criteria to ensure a reliable assembly with the FingerPrinted Contig (FPC) software, which often results in short contig lengths (of 3-5 clones before merging) as well as an unreliable assembly in some difficult regions. Difficulties can originate from a non-linear topological structure of clone overlaps, low power of clone ordering algorithms, and the absence of tools to identify sources of gaps in Minimal Tiling Paths (MTPs).</p> <p>Results</p> <p>To address these problems, we propose a novel approach that: (i) reduces the rate of false connections and Q-clones by using a new cutoff calculation method; (ii) obtains reliable clusters robust to the exclusion of single clone or clone overlap; (iii) explores the topological contig structure by considering contigs as networks of clones connected by significant overlaps; (iv) performs iterative clone clustering combined with ordering and order verification using re-sampling methods; and (v) uses global optimization methods for clone ordering and Band Map construction. The elements of this new analytical framework called Linear Topological Contig (LTC) were applied on datasets used previously for the construction of the physical map of wheat chromosome 3B with FPC. The performance of LTC vs. FPC was compared also on the simulated BAC libraries based on the known genome sequences for chromosome 1 of rice and chromosome 1 of maize.</p> <p>Conclusions</p> <p>The results show that compared to other methods, LTC enables the construction of highly reliable and longer contigs (5-12 clones before merging), the detection of "weak" connections in contigs and their "repair", and the elongation of contigs obtained by other assembly methods.</p