M. ulcerans infection diagnosis by fine needle aspiration

Date du colloque&nbsp;: 04/2009</p

Report of the laboratory confirmation of cases from the CDTUB Pobé, Benin

In 2009, 420 diagnostic samples (corresponding to 301 patients suspected of M. ulcerans infection) from the Centre de Dépistage et de Traitement de l’Ulcère de Buruli of Benin were subjected to IS2404 PCR at the Centre Hospitalier Universitaire of Angers. 180 samples (corresponding to 141 patients) were confirmed positive to M. ulcerans infection by PCR

Defining and targeting high-risk populations in Buruli ulcer–Authors&#039; reply

We thank Jordi Landier and colleagues for their comments about our recent Article in The Lancet Global Health. 1 In their work, Landier and coworkers generalise some of our observations on Buruli ulcer in Benin to those for Cameroon, the country that has the fifth highest prevalence of Buruli ulcer worldwide. Briefly, they make use of age and sex distribution from the Cameroon national census to show that patients aged 5–14 years were twice as likely to be affected by Buruli ulcer as older individuals; and that boys were over-represented in individuals younger than 15 years, women were over-represented in patients aged 15–50 years, and that men and women were equally represented in patients older than 50 years. They advocate the use of national census references to produce incidence rates and incidence rate ratios (IRRs), which they believe to be the proper way to draw valid conclusions

Conidiobolomycose rhinofaciale avec localisations cervicales, thoraciques et brachiales : à propos d’un cas nigérian

We report here the clinical case of a Nigerian adult patient who received medical care during October 2010, at the Center for Diagnosis and Treatment of Buruli ulcer in Pobè (Benin). He presented a massive facial tumor associated with several subcutaneous (cervical, thoracic and upper limbs) nodules, evolving since several years. Tissue samples collected at Pobè medical center were addressed to the mycology and histology laboratories of Angers University Hospital (France), according to the medical exchange agreement between the two institutions about the diagnosis and treatment of Buruli ulcer disease. Histological examination showed a Splendore-Hoeppli phenomenon, consisting of a granulomatous reaction made of eosinophilic polynuclear cells surrounding rare, large and irregular, non-septate hyphae. A filamentous fungus was isolated by cultivation of the clinical samples, which was identified as Conidiobolus coronatus. The patient was treated orally with daily doses of ketoconazole (400 mg per day). After 4 months of treatment, a marked regression of the facial lesion was obtained. A first constructive facial surgery was achieved, but the patient did not attend the second step. This case report allows us to remind the mycological diagnosis of this exotic mycosis, but also to emphasize the main difficulties encountered in medical management in the developing countries

A multiplex kindred with severe Buruli Ulcer dis playing Mendelian inheritance

Buruli Ulcer (BU), caused by Mycobacterium ulcerans, is the third most common mycobacteriosis worldwide after tuberculosis and leprosy, and has been flagged in 1998 by the World Health Organization as an emerging neglected infectious disease.  The physiopathology of Mycobacterium ulcerans infection primarily involves the lipidic toxin mycolactone, a unique feature among mycobacteria. The resulting extensive skin ulcers and/or osteomyelitis cause pathologic scarring responsible for severe life-lasting functional disabilities in the affected population, mainly composed of children of less than 15 year of age.  Buruli ulcer mainly strikes in Western Sub-Saharan Africa but cases have been reported in more than 30 countries worldwide. A common characteristic of the endemic countries consists in the extreme clustering of BU cases in families living in the vicinity of slow-flowing or stagnant waters in rural areas.  However, only a fraction of these heavily exposed individuals develop Buruli ulcer, which leads us to hypothesize a genetic etiology accounting for this variability.    To tackle this issue, we adopted an extreme-phenotype strategy, which consisted in recruiting the most severe of  the  &gt;1,500 BU cases diagnosed and treated during the last 7 years at the Centre de Détection et de Traitement de l\u27Ulcère de Buruli in Pobè, Benin. We report here the analysis of a single highly-informative consanguineous family in which two siblings were affected with exceptionally severe PCR-confirmed BU. The index case suffered from a multifocal edematous form of BU, which disseminated under treatment and involved the four limbs, eventually requiring amputation to heal. Her sister suffered from an edematous form which affected the right arm from shoulder to fingers.  Blood was obtained from the 2 parents, 2 affected and 3 unaffected children. DNA was processed for the genotyping of &gt;900,000 Single Nucleotide Polymorphisms by the Affymetrix Genome-Wide 6.0 array.  After quality control procedures, 120,156 independent SNPs were used for linkage analysis by homozygosity mapping. Three regions, on chromosome 5 and 8, cosegregated with the affected status following a Mendelian recessive inheritance mode, i.e. were shared homozygous by descent by the 2 affected individuals but not the 3 unaffected siblings (yielding the maximum possible LOD score given the pedigree. Sequencing of genes in these regions is currently ongoing and show promising results.  This first description of a genetic etiology for extremely severe BU will have far reaching biological and medical implications. 

Fine needle aspiration for the diagnosis of M. ulcerans infection and for mycolactone detection

Over recent years, management of Buruli ulcer patients has considerably changed with advances in antibiotherapy. Antibiotherapy is particularly effective on nonulcerative forms. However, the bacteriological diagnosis in the early forms is difficult because simple and non-invasive methods are not available. In this study, the diagnostic effectiveness of the Fine Needle aspiration was evaluated on early lesions. Our results showed that PCR from FNA samples, unlike Ziehl-Neelsen staining, is very sensitive on nonulcerative forms like other standard sampling methods (biopsy and punch biopsy). Furthermore, mycolactone was detected in aspirated liquid from lesions in mouse experimentally infected by M. ulcerans and in FNA from Buruli ulcer patients. This is a crucial observation to encourage the development of diagnosis test based on mycolactone detection. Moreover, mycolactone was never detected in aspirated liquid from a patient treated by antibiotherapy. To conclude, fine needle aspiration is a simple, fast, painless, accurate and inexpensive method of sampling and could be used for diagnosis of M. ulcerans infection