Comparative Study of the Sensitivity of Different Diagnostic Methods for the Laboratory Diagnosis of Buruli Ulcer Disease (original) (raw)
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A stepwise approach to the laboratory diagnosis of Buruli ulcer disease
Tropical Medicine and International Health, 2006
objective In view of technical and financial limitations in areas of endemicity, the current practice and recommendations for the laboratory diagnosis of Buruli ulcer disease (BUD) may have to be reconsidered. We reviewed diagnostic results in order to explore options for a modified, more practicable, cost-effective and timely approach to the laboratory diagnosis of BUD.
Journal of Clinical Microbiology, 2005
Punch biopsy specimens from Mycobacterium ulcerans disease lesions were used to compare the sensitivities and specificities of direct smear, culture, PCR, and histopathology in making a diagnosis of M. ulcerans disease in a field setting. PCR for the insertion element IS2404 was modified to include uracil-N-glycosylase and deoxyuridine triphosphate instead of deoxythymidine triphosphate to reduce the risk of cross contamination. The "gold standard" for confirmation of clinically diagnosed Buruli ulcer was a definite histological diagnosis, a positive culture for M. ulcerans, or a smear positive for acid-fast bacilli (AFB), together with a possible histological diagnosis. For 70 clinically diagnosed cases of M. ulcerans disease, the modified PCR was 98% sensitive and gave a rapid result. The sensitivities of microscopy, culture, and histology were 42%, 49%, and 82%, respectively. The use of a 4-mm punch biopsy specimen was preferred to a 6-mm punch biopsy specimen since the wound was less likely to bleed and to need stitching. Given adequate technical expertise and the use of controls, the PCR was viable in a teaching hospital setting in Ghana; and in routine practice, we would recommend the use of Ziehl-Neelsen staining of biopsy specimens to detect AFB, followed by PCR, in AFBnegative cases only, in order to minimize costs. Histology and culture remain important as quality control tests, particularly in studies of treatment efficacy.
Journal of Clinical Microbiology, 2009
Invasive punch or incisional skin biopsy specimens are currently employed for the bacteriological confirmation of the clinical diagnosis of Buruli ulcer (BU), a cutaneous infectious disease caused by Mycobacterium ulcerans. The efficacy of fine-needle aspirates (FNA) using fine-gauge needles (23G by 25 mm) for the laboratory confirmation of BU was compared with that of skin tissue fragments obtained in parallel by excision or punch biopsy. In three BU treatment centers in Benin, both types of diagnostic material were obtained from 33 clinically suspected cases of BU and subjected to the same laboratory analyses: i.e., direct smear examination, IS2404 PCR, and in vitro culture. Twenty-three patients, demonstrating 17 ulcerative and 6 nonulcerative lesions, were positive by at least two tests and were therefore confirmed to have active BU. A total of 68 aspirates and 68 parallel tissue specimens were available from these confirmed patients. When comparing the sensitivities of the three confirmation tests between FNA and tissue specimens, the latter yielded more positive results, but only for PCR was this significant. When only nonulcerative BU lesions were considered, however, the sensitivities of the confirmation tests using FNA and tissue specimens were not significantly different. Our results show that the minimally invasive FNA technique offers enough sensitivity to be used for the diagnosis of BU in nonulcerative lesions.
Clinical and Laboratory Diagnosis of Buruli Ulcer Disease: A Systematic Review
Canadian Journal of Infectious Diseases and Medical Microbiology, 2016
Background.Buruli ulcer (BU) is a necrotizing cutaneous infection caused byMycobacterium ulcerans.Early diagnosis is crucial to prevent morbid effects and misuse of drugs. We review developments in laboratory diagnosis of BU, discuss limitations of available diagnostic methods, and give a perspective on the potential of using aptamers as point-of-care.Methods.Information for this review was searched through PubMed, web of knowledge, and identified data up to December 2015. References from relevant articles and reports from WHO Annual Meeting of the Global Buruli Ulcer initiative were also used. Finally, 59 articles were used.Results.The main laboratory methods for BU diagnosis are microscopy, culture, PCR, and histopathology. Microscopy and PCR are used routinely for diagnosis. PCR targetingIS2404is the gold standard for laboratory confirmation. Culture remains the only method that detects viable bacilli, used for diagnosing relapse and accrued isolates for epidemiological investiga...
Implementation of a National Reference Laboratory for Buruli Ulcer Disease in Togo
PLoS Neglected Tropical Diseases, 2013
Background: In a previous study PCR analysis of clinical samples from suspected cases of Buruli ulcer disease (BUD) from Togo and external quality assurance (EQA) for local microscopy were conducted at an external reference laboratory in Germany. The relatively poor performance of local microscopy as well as effort and time associated with shipment of PCR samples necessitated the implementation of stringent EQA measures and availability of local laboratory capacity. This study describes the approach to implementation of a national BUD reference laboratory in Togo.
Clinical Infectious Diseases, 2018
See the Editorial Commentary by van der Werf on pages 835-6.) Background. The diagnosis of the neglected tropical skin and soft tissue disease Buruli ulcer (BU) is made on clinical and epidemiological grounds, after which treatment with BU-specific antibiotics is initiated empirically. Given the current decline in BU incidence, clinical expertise in the recognition of BU is likely to wane and laboratory confirmation of BU becomes increasingly important. We therefore aimed to determine the diagnostic accuracy of clinical signs and microbiological tests in patients presenting with lesions clinically compatible with BU. Methods. A total of 227 consecutive patients were recruited in southern Benin and evaluated by clinical diagnosis, direct smear examination (DSE), polymerase chain reaction (PCR), culture, and histopathology. In the absence of a gold standard, the final diagnosis in each patient was made using an expert panel approach. We estimated the accuracy of each test in comparison to the final diagnosis and evaluated the performance of 3 diagnostic algorithms. Results. Among the 205 patients with complete data, the attending clinicians recognized BU with a sensitivity of 92% (95% confidence interval [CI], 85%-96%), which was higher than the sensitivity of any of the laboratory tests. However, 14% (95% CI, 7%-24%) of patients not suspected to have BU at diagnosis were classified as BU by the expert panel. The specificities of all diagnostics were high (≥91%). All diagnostic algorithms had similar performances. Conclusions. A broader clinical suspicion should be recommended to reduce missed BU diagnoses. Taking into consideration diagnostic accuracy, time to results, cost-effectiveness, and clinical generalizability, a stepwise diagnostic approach reserving PCR to DSE-negative patients performed best.
Journal of Clinical Microbiology, 2003
West Africa. Laboratory confirmation of BUD is complicated as no "gold standard" for diagnosis exists. A nested primer PCR based on IS2404 has shown promise as a diagnostic assay. We evaluated the IS2404-based PCR to detect M. ulcerans DNA in tissue specimens from 143 BUD patients diagnosed according to the World Health Organization BUD clinical case definition in Ghana. Comparisons were made with culture and histopathology results. Variables influencing detection rate tested in this PCR protocol included the amount of tissue used and the stage of disease. The nested PCR was repeated on DNA extracted from a different part of the same biopsy specimen of 21 culture-positive samples. Of all 143 specimens, 107 (74.8%; 95% confidence interval, 68 to 82%) showed the presence of M. ulcerans DNA by PCR. Of the 78 histology-confirmed BUD patient samples, 64 (83%) were PCR positive. Detection rates were influenced neither by the amount of tissue processed for PCR nor by the stage of disease (preulcerative or ulcerative). Taken together, the two nested PCR tests on the subset of 21 culture-positive samples were able to detect M. ulcerans DNA in all 21 cultureconfirmed patients. For future studies, small tissue samples, e.g., punch biopsy samples, might be sufficient for case confirmation.
PLOS Neglected Tropical Diseases
Buruli ulcer is one of the 20 neglected tropical diseases in the world. This necrotizing hypodermitis is a chronic debilitating disease caused by an environmental Mycobacterium ulcerans. At least 33 countries with tropical, subtropical and temperate climates have reported Buruli ulcer in African countries, South America and Western Pacific regions. Majority of cases are spread across West and Central Africa. The mode of transmission is unclear, hindering the implementation of adequate prevention for the population. Currently, early diagnosis and treatment are crucial to minimizing morbidity, costs and preventing long-term disability. Biological confirmation of clinical diagnosis of Buruli ulcer is essential before starting chemotherapy. Indeed, differential diagnosis are numerous and Buruli ulcer has varying clinical presentations. Up to now, the gold standard biological confirmation is the quantitative PCR, targeting the insertion sequence IS2404 of M. ulcerans performed on cutaneo...