Changes in Inflammatory Markers in Patients Treated for Buruli Ulcer and Their Ability to Predict Paradoxical Reactions.

Mycobacterium ulcerans causes Buruli ulcer, the third most frequent mycobacterial disease after tuberculosis and leprosy. Transient clinical deteriorations, known as paradoxical reactions (PRs), occur in some patients during or after antibiotic treatment. We investigated the clinical and biological features of PRs in a prospective cohort of 41 patients with Buruli ulcer from Benin. Neutrophil counts decreased from baseline to day 90, and interleukin 6 (IL-6), granulocyte colony-stimulating factor, and vascular endothelial growth factor were the cytokines displaying a significant monthly decrease relative to baseline. PRs occurred in 10 (24%) patients. The baseline biological and clinical characteristics of the patients presenting with PRs did not differ significantly from those of the other patients. However, the patients with PRs had significantly higher IL-6 and tumor necrosis factor alpha (TNF-α) concentrations on days 30, 60, and 90 after the start of antibiotic treatment. The absence of a decrease in IL-6 and TNF-α levels during treatment should alert clinicians to the possibility of PR onset.

An Overview of 10 Years of Activity of a Molecular Laboratory for Buruli Ulcer Diagnosis at a Field Hospital in Benin.

Buruli ulcer (BU) is a neglected tropical disease caused by Mycobacterium ulcerans. Early diagnosis is crucial to prevent morbidity. In November 2012, a field laboratory fully equipped for the rapid on-site quantitative PCR (qPCR) diagnosis of M. ulcerans was established at the Buruli ulcer treatment center (CDTLUB) center in Pobè Benin, a region where BU is endemic. We describe its first 10 years of activity and its gradual evolution into an expert laboratory for BU diagnosis. From 2012 to 2022, the laboratory analyzed 3,018 samples from patients attending consultations for suspected BU at the CDTLUB in Pobè. Ziehl-Neelsen staining and qPCR targeting the IS2404 sequence were performed. Since 2019, the laboratory has also received and analyzed 570 samples from other centers. The laboratory confirmed the diagnosis of BU by qPCR for 39.7% samples: M. ulcerans DNA was detected in 34.7% of swabs, 47.2% of all fine needle aspiration samples (FNA) and 44.6% of all skin biopsy specimens. Positive Ziehl-Neelsen staining results were obtained for 19.0% samples. Bacterial load, estimated by qPCR, was significantly greater for the Ziehl-Neelsen-positive samples than for Ziehl-Neelsen-negative samples, and detection rates were highest for FNA samples. Overall, 26.3% of the samples received from other centers were positive for BU. Most of these samples were sent by the CDTLUBs of Lalo, Allada, and Zagnanado, Benin. The establishment of the laboratory in the CDTLUB of Pobè has been a huge success. Optimal patient care depends on the close proximity of a molecular biology structure to BU treatment centers. Finally, FNA should be promoted among caregivers. IMPORTANCE Here, we describe the first 10 years of activity at a field laboratory established at the Buruli ulcer treatment center (CDTLUB) in Pobè, Benin, a country in which Mycobacterium ulcerans is endemic. Between 2012 and 2022, the laboratory analyzed 3,018 samples from patients consulting the CDTLUB of Pobè with a suspected clinical BU. Ziehl-Neelsen staining and qPCR targeting the IS2404 sequence were performed. In total, 39.7% of samples tested positive by qPCR and 19.0% tested positive by Ziehl-Neelsen staining. Detection rates were highest for FNA samples, and the bacterial loads estimated by qPCR were significantly higher for Ziehl-Neelsen-positive samples than for Ziehl-Neelsen-negative samples. Since 2019, the laboratory has also analyzed 570 samples received from outside the CDTLUB of Pobè, 26.3% of which were positive for BU. Most of these samples were sent by the CDTLUBs of Lalo, Allada, and Zagnanado in Benin. The establishment of the laboratory in the CDTLUB of Pobè has been a huge success, with major benefits for both the medical staff and patients. Our findings illustrate that the usefulness and feasibility of having a diagnostic center in rural Africa, where the disease is endemic, is a key part of optimal patient care, and that FNA should be promoted to increase detection rates.

Findings in patients from Benin with osteomyelitis and polymerase chain reaction-confirmed Mycobacterium ulcerans infection.

BACKGROUND: Mycobacterium ulcerans is known to cause Buruli ulcer (BU), a necrotizing skin disease leading to extensive cutaneous and subcutaneous destruction and functional limitations. However, M. ulcerans infections are not limited to skin, and osteomyelitis, still poorly described in the literature, occurs in numerous young patients in Africa. METHODS: In a retrospective matched case-control study conducted in a highly endemic area in Benin, we analyzed demographic, clinical, biological, and radiological features in all patients with M. ulcerans infections with bone involvement, identified from a cohort of 1257 patients with polymerase chain reaction-proved M. ulcerans infections. RESULTS: The 81 patients studied had a median age of 11 years (interquartile range, 7-16 years) and were predominantly male (male-female ratio, 2:1). Osteomyelitis was observed beneath active BU lesions (60.5%) or at a distance from active or apparently healed BU lesions (14.8%) but also in patients without a history of BU skin lesions (24.7%). These lesions had an insidious course, with nonspecific clinical findings leading to delayed diagnosis. A comparison with findings in 243 age- and sex-matched patients with BU without osteomyelitis showed that case patients were less likely to have received BCG immunization than controls (33.3% vs 52.7%; P = .01). They were also at higher risk of longer hospital stay (118 vs 69 days; P = .001), surgery (92.6% vs 63.0%; P = .001), and long-term crippling sequelae (55.6% vs 15.2%; P < .001). CONCLUSIONS: This study highlighted the difficulties associated with diagnosis of M. ulcerans osteomyelitis, with one-fourth of patients having no apparent history of BU skin lesions, including during the current course of illness. Delays in treatment contributed to the high proportion (55.6%) of patients with crippling sequelae.

Establishment of quantitative PCR (qPCR) and culture laboratory facilities in a field hospital in benin: 1-year results.

No simple diagnostic tool is available to confirm Mycobacterium ulcerans infection, which is an emerging disease reported in many rural areas of Africa. Here, we report the 1-year results of a hospital laboratory that was created in an area of endemicity of Benin to facilitate the diagnosis of M. ulcerans infection.

Wound colonization with methicillin-resistant Staphylococcus aureus and hypotheses about acquisition routes in rural health care settings in Sub-Saharan Africa: Perspective from a center devoted to the treatment of cutaneous neglected tropical diseases.

We identified a high prevalence (46.4%) of wound colonization with methicillin-resistant Staphylococcus aureus (MRSA) in patients hospitalized in a center devoted to the treatment of cutaneous tropical diseases in Benin. The proportion of MRSA among S aureus isolates was 54.3%. Thirty percent of these MRSA were identified in outpatients. The analysis of pulsed-field gel electrophoresis demonstrated an important diversity of strains but also identified 8 small clusters containing between 2 and 4 isolates suggesting cross-transmission.

Oral treatment for Mycobacterium ulcerans infection: results from a pilot study in Benin.

Mycobacterium ulcerans infection is responsible for severe skin lesions in sub-Saharan Africa. We enrolled 30 Beninese patients with Buruli ulcers in a pilot study to evaluate efficacy of an oral chemotherapy using rifampicin plus clarithromycin during an 8-week period. The treatment was well tolerated, and all patients were healed by 12 months after initiation of therapy without relapse.

Disseminated and ulcerative basidiobolomycosis simulating a Buruli ulcer in an immunocompetent girl in Southern Benin.

Basidiobolomycosis is a subcutaneous mycosis, for which non-specific clinical presentation can be a source of diagnostic wandering. A 5-year-old girl was brought for consultation with chronic ulcers of the pelvic limbs evolving for 8 months. The lesions started when the girl was 18 months old with a painless, pruritic nodule of the right buttock, indurated placard following progressive extension to the pelvic limbs, back and abdomen, and secondarily ulcerated in several places. On examination, there was an alteration of the general condition, a large, indurated and erythematous plaque, with sharp edges. On this plaque, there were nodular lesions and necrotic ulcers, with detached margins. The left knee was blocked in flexion. Ziehl staining and polymerase chain reaction for Mycobacterium ulcerans were negative. The histopathological picture was suggestive of basidiobolomycosis. The evolution was favorable after giving her ketoconazole (100mg per day) for 14 weeks associated with surgery and physiotherapy. This clinical case confirms the difficulties in diagnosing basidiobolomycosis, especially in endemic areas of Buruli ulcer.

Microdeletion on chromosome 8p23.1 in a familial form of severe Buruli ulcer.

Buruli ulcer (BU), the third most frequent mycobacteriosis worldwide, is a neglected tropical disease caused by Mycobacterium ulcerans. We report the clinical description and extensive genetic analysis of a consanguineous family from Benin comprising two cases of unusually severe non-ulcerative BU. The index case was the most severe of over 2,000 BU cases treated at the Centre de Dépistage et de Traitement de la Lèpre et de l'Ulcère de Buruli, Pobe, Benin, since its opening in 2003. The infection spread to all limbs with PCR-confirmed skin, bone and joint infections. Genome-wide linkage analysis of seven family members was performed and whole-exome sequencing of both patients was obtained. A 37 kilobases homozygous deletion confirmed by targeted resequencing and located within a linkage region on chromosome 8 was identified in both patients but was absent from unaffected siblings. We further assessed the presence of this deletion on genotyping data from 803 independent local individuals (402 BU cases and 401 BU-free controls). Two BU cases were predicted to be homozygous carriers while none was identified in the control group. The deleted region is located close to a cluster of beta-defensin coding genes and contains a long non-coding (linc) RNA gene previously shown to display highest expression values in the skin. This first report of a microdeletion co-segregating with severe BU in a large family supports the view of a key role of human genetics in the natural history of the disease.

Buruli ulcer in South Western Nigeria: a retrospective cohort study of patients treated in Benin.

Nigeria is known to be endemic to Buruli ulcer, but epidemiological data are remarkably rare. Here, we present a large cohort of 127 PCR-confirmed M. ulcerans infection patients coming from Nigeria and treated in a neighbouring country, Benin. Severe lesions and delay of consultation are factors that should encourage establishment of a treatment centre in South Western Nigeria.

Clinical epidemiology of laboratory-confirmed Buruli ulcer in Benin: a cohort study.

BACKGROUND: Buruli ulcer, caused by Mycobacterium ulcerans, was identified as a neglected emerging infectious disease by WHO in 1998. Although Buruli ulcer is the third most common mycobacterial disease worldwide, understanding of the disease is incomplete. We analysed a large cohort of laboratory-confirmed cases of Buruli ulcer from Pobè, Benin, to provide a comprehensive description of the clinical presentation of the disease, its variation with age and sex, and its effect on the occurrence of permanent functional sequelae. METHODS: Between Jan 1, 2005, and Dec 31, 2011, we prospectively collected clinical and laboratory data from all patients with Buruli ulcer diagnosed at the Centre de Dépistage et de Traitement de l'Ulcère de Buruli in Pobè, Benin. We followed up patients to assess the frequency of permanent functional sequelae. All analyses were done on cases that were laboratory confirmed. FINDINGS: 1227 cases of laboratory-confirmed Buruli ulcer were included in the analysis. Typically, patients with Buruli ulcer were children (median age at diagnosis 12 years) presenting with a unique (1172 [96%]) large (≥15 cm, 444 [36%]) ulcerative (805 [66%]) lesion of the lower limb (733 [60%]). Atypical clinical presentation of Buruli ulcer included Buruli ulcer osteomyelitis with no identifiable present or past Buruli ulcer skin lesions, which was recorded in at least 14 patients. The sex ratio of Buruli ulcer widely varied with age, with male patients accounting for 57% (n=427) of patients aged 15 years and younger, but only 33% (n=158) of those older than 15 years (odds ratio [OR] 2·59, 95% CI 2·04-3·30). Clinical presentation of Buruli ulcer was significantly dependent on age and sex. 54 (9%) male patients had Buruli ulcer osteomyelitis, whereas only 28 (4%) of female patients did (OR 2·21, 95% CI 1·39-3·59). 1 year after treatment, 229 (22% of 1043 with follow-up information) patients presented with permanent functional sequelae. Presentation with oedema, osteomyelitis, or large (≥15 cm in diameter), or multifocal lesions was significantly associated with occurrence of permanent functional sequelae (OR 7·64, 95% CI 5·29-11·31) and operationally defines severe Buruli ulcer. INTERPRETATION: Our findings have important clinical implications for daily practice, including enhanced surveillance for early detection of osteomyelitis in boys; systematic search for M ulcerans in osteomyelitis cases of non-specific aspect in areas endemic for Buruli ulcer; and specific disability prevention for patients presenting with osteomyelitis, oedema, or multifocal or large lesions. Our findings also suggest a crucial underestimation of the burden of Buruli ulcer in Africa and raise key questions about the contribution of environmental and physiopathological factors to the recorded heterogeneity of the clinical presentation of Buruli ulcer. FUNDING: Agence Nationale de la Recherche (ANR), Fondation Raoul Follereau, Fondation pour la Recherche Médicale (FRM), and Institut des Maladies Génétiques (IMAGINE).

Secondary Buruli ulcer skin lesions emerging several months after completion of chemotherapy: paradoxical reaction or evidence for immune protection?

BACKGROUND: The neglected tropical disease Buruli ulcer (BU) caused by Mycobacterium ulcerans is an infection of the subcutaneous tissue leading to chronic ulcerative skin lesions. Histopathological features are progressive tissue necrosis, extracellular clusters of acid fast bacilli (AFB) and poor inflammatory responses at the site of infection. After the recommended eight weeks standard treatment with rifampicin and streptomycin, a reversal of the local immunosuppression caused by the macrolide toxin mycolactone of M. ulcerans is observed. METHODOLOGY/PRINCIPAL FINDINGS: We have conducted a detailed histopathological and immunohistochemical analysis of tissue specimens from two patients developing multiple new skin lesions 12 to 409 days after completion of antibiotic treatment. Lesions exhibited characteristic histopathological hallmarks of Buruli ulcer and AFB with degenerated appearance were found in several of them. However, other than in active disease, lesions contained massive leukocyte infiltrates including large B-cell clusters, as typically found in cured lesions. CONCLUSION/SIGNIFICANCE: Our histopathological findings demonstrate that the skin lesions emerging several months after completion of antibiotic treatment were associated with M. ulcerans infection. During antibiotic therapy of Buruli ulcer development of new skin lesions may be caused by immune response-mediated paradoxical reactions. These seem to be triggered by mycobacterial antigens and immunostimulators released from clinically unrecognized bacterial foci. However, in particular the lesions that appeared more than one year after completion of antibiotic treatment may have been associated with new infection foci resolved by immune responses primed by the successful treatment of the initial lesion.

Promising clinical efficacy of streptomycin-rifampin combination for treatment of buruli ulcer (Mycobacterium ulcerans disease).

According to recommendations of the 6th WHO Advisory Committee on Buruli ulcer, directly observed treatment with the combination of rifampin and streptomycin, administered daily for 8 weeks, was recommended to 310 patients diagnosed with Buruli ulcer in Pobè, Bénin. Among the 224 (72%) eligible patients for whom treatment was initiated, 215 (96%) were categorized as treatment successes, and 9, including 1 death and 8 losses to follow-up, were treatment failures. Of the 215 successfully treated patients, 102 (47%) were treated exclusively with antibiotics and 113 (53%) were treated with antibiotics plus surgical excision and skin grafting. The size of lesions at treatment initiation was the major factor associated with surgical intervention: 73% of patients with lesions of >15 cm in diameter underwent surgery, whereas only 17% of patients with lesions of <5 cm had surgery. No patient discontinued therapy for side effects from the antibiotic treatment. One year after stopping treatment, 208 of the 215 patients were actively retrieved to assess the long-term therapeutic results: 3 (1.44%) of the 208 retrieved patients had recurrence of Mycobacterium ulcerans disease, 2 among the 107 patients treated only with antibiotics and 1 among the 108 patients treated with antibiotics plus surgery. We conclude that the WHO-recommended streptomycin-rifampin combination is highly efficacious for treating M. ulcerans disease. Chemotherapy alone was successful in achieving cure in 47% of cases and was particularly effective against ulcers of less than 5 cm in diameter.