Serum levels of neopterin during antimicrobial treatment for Mycobacterium ulcerans infection.

Neopterin is closely associated with activation of the cellular immune system. Neopterin levels differed between controls and patients with Buruli ulcer disease. No differences between patients with or without paradoxical responses were observed. Therefore, neopterin has no value in detecting paradoxical responses among patients with limited Buruli ulcer disease. Neopterin levels were lower in patients receiving clarithromycin. This finding might indicate a slower cellular immune recovery, with possible consequences in future therapy with clarithromycin.

Paradoxical responses after start of antimicrobial treatment in Mycobacterium ulcerans infection.

BACKGROUND: Antimicrobial killing in mycobacterial infections may be accompanied by (transient) clinical deterioration, known as paradoxical reaction. To search for patterns reflecting such reactions in the treatment of Buruli ulcer (Mycobacterium ulcerans infection), the evolution of lesions of patients treated with antimicrobials was prospectively assessed. METHODS: The lesion size of participants of the BURULICO antimicrobial trial (with lesions ≤10 cm cross-sectional diameter) was assessed by careful palpation and recorded by serial acetate sheet tracings. Patients were treated with antimicrobials for 8 weeks. For the size analysis, participants whose treatment had failed, had skin grafting, or were coinfected with human immunodeficiency virus were excluded. For every time point, surface area was compared with the previous assessment. A generalized additive mixed model was used to study lesion evolution. Nonulcerative lesions were studied using digital images recording possible subsequent ulceration. RESULTS: Of 151 participants, 134 were included in the lesion size analysis. Peak paradoxical response occurred at week 8; >30% of participants showed an increase in lesion size as compared with the previous (week 6) assessment. Seventy-five of 90 (83%) of nonulcerative lesions ulcerated after start of treatment. Nine participants developed new lesions during or after treatment. All lesions subsequently healed. CONCLUSIONS: After start of antimicrobial treatment for Buruli ulcer, new or progressive ulceration is common before healing sets in. This paradoxical response, most prominent at the end of the 8-week antimicrobial treatment, should not be misinterpreted as failure to respond to treatment. Clinical Trials Registration. ClinicalTrials.gov, NCT00321178.

A genotypic approach for detection, identification, and characterization of drug resistance in Mycobacterium ulcerans in clinical samples and isolates from Ghana.

Standardized antimycobacterial therapy is considered the treatment of choice for Buruli ulcer disease. To assess the prevalence of drug resistance among clinical Mycobacterium ulcerans isolates in Ghana, we conducted a sequence-based approach to detect mutations associated with drug resistance. We subjected clinical samples to direct DNA sequencing of rpoB and rpsL genes and compared culture and whole-genome extracts regarding the efficiency of sequence analysis; 99.1% (rpoB) and 100% (rpsL) of the patients harbored M. ulcerans wild type. In one isolate (0.9%), a point mutation of the rpoB gene at codon Ser522 leading to an amino acid change was detected. Culture extracts yielded a significantly higher sequencing efficiency than whole-genome extracts. Our data suggest a low level of drug resistance in Ghana. However, mutations associated with drug resistance do occur and require monitoring. Improved techniques are necessary to enhance the efficiency of sequence analysis of whole-genome extracts.

Antimicrobial treatment for early, limited Mycobacterium ulcerans infection: a randomised controlled trial.

BACKGROUND: Surgical debridement was the standard treatment for Mycobacterium ulcerans infection (Buruli ulcer disease) until WHO issued provisional guidelines in 2004 recommending treatment with antimicrobial drugs (streptomycin and rifampicin) in addition to surgery. These recommendations were based on observational studies and a small pilot study with microbiological endpoints. We investigated the efficacy of two regimens of antimicrobial treatment in early-stage M ulcerans infection. METHODS: In this parallel, open-label, randomised trial undertaken in two sites in Ghana, patients were eligible for enrolment if they were aged 5 years or older and had early (duration <6 months), limited (cross-sectional diameter <10 cm), M ulcerans infection confirmed by dry-reagent-based PCR. Eligible patients were randomly assigned to receive intramuscular streptomycin (15 mg/kg once daily) and oral rifampicin (10 mg/kg once daily) for 8 weeks (8-week streptomycin group; n=76) or streptomycin and rifampicin for 4 weeks followed by rifampicin and clarithromycin (7.5 mg/kg once daily), both orally, for 4 weeks (4-week streptomycin plus 4-week clarithromycin group; n=75). Randomisation was done by computer-generated minimisation for study site and type of lesion (ulceration or no ulceration). The randomly assigned allocation was sent from a central site by cell-phone text message to the study coordinator. The primary endpoint was lesion healing at 1 year after the start of treatment without lesion recurrence or extensive surgical debridement. Analysis was by intention-to-treat. This trial is registered with ClinicalTrials.gov, number NCT00321178. FINDINGS: Four patients were lost to follow-up (8-week streptomycin, one; 4-week streptomycin plus 4-week clarithromycin, three). Since these four participants had healed lesions at their last assessment, they were included in the analysis for the primary endpoint. 73 (96%) participants in the 8-week streptomycin group and 68 (91%) in the 4-week streptomycin plus 4-week clarithromycin group had healed lesions at 1 year (odds ratio 2.49, 95% CI 0.66 to infinity; p=0.16, one-sided Fisher's exact test). No participants had lesion recurrence at 1 year. Three participants had vestibulotoxic events (8-week streptomycin, one; 4-week streptomycin plus 4-week clarithromycin, two). One participant developed an injection abscess and two participants developed an abscess close to the initial lesion, which was incised and drained (all three participants were in the 4-week streptomycin plus 4-week clarithromycin group). INTERPRETATION: Antimycobacterial treatment for M ulcerans infection is effective in early, limited disease. 4 weeks of streptomycin and rifampicin followed by 4 weeks of rifampicin and clarithromycin has similar efficacy to 8 weeks of streptomycin and rifampicin; however, the number of injections of streptomycin can be reduced by switching to oral clarithromycin after 4 weeks. FUNDING: European Union (EU FP6 2003-INCO-Dev2-015476) and Buruli Ulcer Groningen Foundation.

Comparative study of the sensitivity of different diagnostic methods for the laboratory diagnosis of Buruli ulcer disease.

BACKGROUND: Several diagnostic laboratory methods are available for case confirmation of Buruli ulcer disease. This study assessed the sensitivity of various diagnostic tests in relation to clinical presentation of the disease, type of diagnostic specimen, and treatment history. METHODS: Swab samples, 3-mm punch biopsy tissue specimens, and surgically excised tissue specimens from 384 individuals with suspected Buruli ulcer disease were obtained at 9 different study sites in Ghana and were evaluated with dry reagent-based polymerase chain reaction (PCR), microscopic examination, culture, and histopathological analysis. The study subjects presented with nonulcerative and ulcerative lesions and were divided into 3 treatment groups: (1) previously untreated patients scheduled for antimycobacterial treatment, (2) patients treated with surgery alone, and (3) patients treated with surgery in combination with previous antimycobacterial treatment. RESULTS: Of 384 suspected cases of Buruli ulcer disease, 268 were confirmed by at least 1 positive test result. The overall sensitivity of PCR (85%) was significantly higher than that of microscopic examination (57%) and culture (51%). After data were stratified by treatment group, type of lesion, and diagnostic specimen type, analysis revealed that PCR of 3-mm punch biopsy tissue specimens (obtained from previously untreated nonulcerative lesions) and of swab samples (obtained from previously untreated ulcers) had the highest diagnostic sensitivity (94% and 90%, respectively). Although duration of the disease did not significantly influence the sensitivity of any test, previous antimycobacterial treatment was significantly associated with decreased sensitivity of PCR and culture. CONCLUSIONS: Across all subgroups, PCR had the highest sensitivity. PCR assessment of 3-mm punch biopsy tissue specimens proved to be the best diagnostic tool for nonulcerative lesions, and PCR assessment of swab samples was the best diagnostic tool for ulcerative lesions. For monitoring of antimycobacterial treatment success within controlled trials, however, only culture is appropriate.

Measuring impairment caused by leprosy: inter-tester reliability of the WHO disability grading system.

This paper reports the results of a study on the inter-tester reliability of the WHO disability grading system. The WHO disability grading system is the most frequently used method of grading impairment in leprosy patients. With this method, a grade of 0-2 is assigned to each of six individual body sites (both eyes, hands and feet). The maximum grade of any of these sites is used as an overall indicator of the person's impairment status. To date, the WHO disability grading scale has not been subjected to reliability testing. The reliability of the grading system depends on the operational definitions of the grades, the way the tester interprets these definitions and the skill of the tester. It is therefore important that the definitions are unambiguous and leave as little room as possible for multiple interpretations. Three testers with varying degrees of experience did paired assessments on a total of 150 leprosy patients in the Leprosy Mission Hospital Purulia, India, using recently published operational definitions of the WHO disability grades. For every patient, they determined the maximum grade (minimum 0, maximum 2), and calculated the impairment sum-score (EHF score), adding up the six grades for eyes, hands and feet (minimum 0, maximum 12). The weighted Kappa statistic (Kw) was used as the coefficient of inter-tester reliability. A kappa of 0 represents agreement no better than chance, and 1.0 complete (chance-corrected) agreement. Kw values of > or = 0.80 are considered very good and adequate for monitoring and research. Weighted Kappa analysis yielded a reliability coefficient of 0.89 (95%CI 0.84-0.94) for the maximum grade and a Kw of 0.97 (95%CI 0.96-0.98) for the EHF score. We concluded that, when using standard operational definitions, the WHO disability grading system can be used reliably in the hands of both experienced and inexperienced testers, provided adequate training has been given. Reliability should be evaluated further in a field setting, when used by primary health care workers. It is recommended that the 'WHO disability grading' be renamed 'WHO impairment grading', using the terminology as defined by the International Classification of Functioning, Disability and Health (ICF).