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Park JS. Issues Related to the Updated 2014 Korean Guidelines for Tuberculosis. Tuberc Respir Dis (Seoul) 2016; 79:1-4. [PMID: 26770228 PMCID: PMC4701788 DOI: 10.4046/trd.2016.79.1.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 11/06/2015] [Accepted: 11/10/2015] [Indexed: 11/24/2022] Open
Abstract
Tuberculosis (TB) remains a major public health problem in South Korea. The Joint Committee for the Development of Korean Guidelines for Tuberculosis published the Korean Guidelines for Tuberculosis in 2011 to provide evidence-based practical recommendations to health care workers caring for patients with TB in South Korea. After reviewing recent national and international scientific data on TB, the committee updated the Korean guidelines for TB in 2014. This article presents some practical issues related to the 2014 updated guidelines: namely use of the Mycobacterium tuberculosis - polymerase chain reaction assay and the Xpert MTB/RIF assay in the diagnosis of TB, as well as medical treatment for patients with multidrug-resistant TB.
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Affiliation(s)
- Jae Seuk Park
- Department of Internal Medicine, Dankook University College of Medicine, Cheonan, Korea
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53
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Lee RS, Behr MA. The implications of whole-genome sequencing in the control of tuberculosis. Ther Adv Infect Dis 2015; 3:47-62. [PMID: 27034776 DOI: 10.1177/2049936115624630] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The availability of whole-genome sequencing (WGS) as a tool for the diagnosis and clinical management of tuberculosis (TB) offers considerable promise in the fight against this stubborn epidemic. However, like other new technologies, the best application of WGS remains to be determined, for both conceptual and technical reasons. In this review, we consider the potential value of WGS in the clinical laboratory for the detection of Mycobacterium tuberculosis and the prediction of antibiotic resistance. We also discuss issues pertaining to data generation, interpretation and dissemination, given that WGS has to date been generally performed in research labs where results are not necessarily packaged in a clinician-friendly format. Although WGS is far more accessible now than it was in the past, the transition from a research tool to study TB into a clinical test to manage this disease may require further fine-tuning. Improvements will likely come through iterative efforts that involve both the laboratories ready to move TB into the genomic era and the front-line clinical/public health staff who will be interpreting the results to inform management decisions.
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Affiliation(s)
- Robyn S Lee
- McGill University, Department of Epidemiology, Biostatistics and Occupational Health, The Research Institute of the McGill University Health Centre and McGill International TB Centre, Montreal, QC, Canada
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Abstract
The phenotypic methods of smear microscopy, culture and indirect drug susceptibility testing (DST) remain the 'gold standard' diagnostics for tuberculosis (TB) in 2015. However, this review demonstrates that genotypic methods are in the ascendancy. Current-generation nucleic acid amplification tests (NAATs) are important supplementary tests for the rapid direct detection of (multidrug-resistant) TB in specific clinical settings. Genotypic detection is already the preferred method of detecting rifampicin and pyrazinamide resistance. Next-generation NAATs able to detect about 10 colony forming units/mL of sputum could replace culture as the initial test for detecting TB. Whole genome sequencing could also plausibly replace phenotypic DST but much work is required in method standardisation, database development and elucidation of all resistance gene determinants. The challenge then will be to rollout these increasingly complex and expensive diagnostics in the low-income countries where TB is prevalent.
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Kumar K, Abubakar I. Clinical implications of the global multidrug-resistant tuberculosis epidemic. Clin Med (Lond) 2015; 15 Suppl 6:s37-42. [PMID: 26634680 DOI: 10.7861/clinmedicine.15-6-s37] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Multidrug-resistant tuberculosis (MDR TB) is a significant threat to global health estimated to account for nearly half a million new cases and over 200,000 deaths in 2013. The number of MDR TB cases in the UK has risen over the last 15 years, with ever more complex clinical cases and associated challenging public health and societal implications. In this review, we provide an overview of the epidemiology of MDR TB globally and in the UK, outline the clinical management of MDR TB and summarise recent advances in diagnostics and prospects for new treatment.
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Affiliation(s)
- Kartik Kumar
- Centre for Infectious Disease Epidemiology, Research Department of Infection and Population Health, University College London, London, UK, and The Whittington Hospital NHS Trust, Whittington Health, London, UK
| | - Ibrahim Abubakar
- Centre for Infectious Disease Epidemiology, University College London, London, UK, and MRC Clinical Trials Unit, University College London, London, UK
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Yan L, Xiao H, Zhang Q. Systematic review: Comparison of Xpert MTB/RIF, LAMP and SAT methods for the diagnosis of pulmonary tuberculosis. Tuberculosis (Edinb) 2015; 96:75-86. [PMID: 26786658 DOI: 10.1016/j.tube.2015.11.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 09/29/2015] [Accepted: 11/17/2015] [Indexed: 11/17/2022]
Abstract
Technological advances in nucleic acid amplification have led to breakthroughs in the early detection of PTB compared to traditional sputum smear tests. The sensitivity and specificity of loop-mediated isothermal amplification (LAMP), simultaneous amplification testing (SAT), and Xpert MTB/RIF for the diagnosis of pulmonary tuberculosis were evaluated. A critical review of previous studies of LAMP, SAT, and Xpert MTB/RIF for the diagnosis of pulmonary tuberculosis that used laboratory culturing as the reference method was carried out together with a meta-analysis. In 25 previous studies, the pooled sensitivity and specificity of the diagnosis of tuberculosis were 93% and 94% for LAMP, 96% and 88% for SAT, and 89% and 98% for Xpert MTB/RIF. The I(2) values for the pooled data were >80%, indicating significant heterogeneity. In the smear-positive subgroup analysis of LAMP, the sensitivity increased from 93% to 98% (I(2) = 2.6%), and specificity was 68% (I(2) = 38.4%). In the HIV-infected subgroup analysis of Xpert MTB/RIF, the pooled sensitivity and specificity were 79% (I(2) = 72.9%) and 99% (I(2) = 64.4%). In the HIV-negative subgroup analysis for Xpert MTB/RIF, the pooled sensitivity and specificity were 72% (I(2) = 49.6%) and 99% (I(2) = 64.5%). LAMP, SAT and Xpert MTB/RIF had comparably high levels of sensitivity and specificity for the diagnosis of tuberculosis. The diagnostic sensitivity and specificity of three methods were similar, with LAMP being highly sensitive for the diagnosis of smear-positive PTB. The cost effectiveness of LAMP and SAT make them particularly suitable tests for diagnosing PTB in developing countries.
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Affiliation(s)
- Liping Yan
- Tuberculosis Clinic and Research Center, Shanghai Pulmonary Hospital, Tongji University School of Medicine, No. 507, Zhengmin Road, Shanghai 200433, China
| | - Heping Xiao
- Tuberculosis Clinic and Research Center, Shanghai Pulmonary Hospital, Tongji University School of Medicine, No. 507, Zhengmin Road, Shanghai 200433, China
| | - Qing Zhang
- Tuberculosis Clinic and Research Center, Shanghai Pulmonary Hospital, Tongji University School of Medicine, No. 507, Zhengmin Road, Shanghai 200433, China.
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Alvarez GG, Dyk DDV, Desjardlns M, Yasseen AS, Aaron SD, Cameron DW, Obed N, Baikie M, Pakhale S, Denklnger CM, Sohn H, Pal M. The Feasibility, Accuracy, and Impact of Xpert MTB/RIF Testing in a Remote Aboriginal Community in Canada. Chest 2015; 148:767-773. [PMID: 25789458 DOI: 10.1378/chest.14-2948] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Xpert MTB/RIF testing for Mycobacterium tuberculosis and rifampin resistance is being used extensively in countries with a high burden of TB. However, recent evidence suggests that it may not have the same accuracy or impact in high-income, low-burden TB countries. METHODS A prospective, pragmatic study was done between March 2012 and March 2014 to determine the feasibility, accuracy, and impact on TB disease management provided by the Xpert test in a remote, medically underserved, predominantly Inuit population in Iqaluit, Nunavut, Canada. RESULTS A total of 453 Xpert tests were run on sputum samples from 344 patients with suspected TB. Twenty-seven patients were identified as having active TB disease by culture. There were no cases of drug-resistant TB. Using culture as the gold standard, one Xpert test compared with one, two, or three sputum samples cultured per patient had a sensitivity of 85% (95% CI, 66%-95%) and a specificity of 99% (95% CI, 97%-100%) for detection of M tuberculosis. The indeterminate rate was 4.4% of all samples run. Treatment initiation was significantly shortened using Xpert vs the national standard of three smears (1.8 days vs 7.7 days, P < .007) and particularly shorter in smear-negative, culture-positive cases (1.8 days vs 37.1 days, P < .008). CONCLUSIONS In a predominantly Inuit population in a remote region of Canada where the burden of TB is high and no TB testing facilities are available, onsite Xpert testing was feasible and accurate and shortened the time to TB treatment initiation.
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Affiliation(s)
- Gonzalo G Alvarez
- Department of Medicine, Division of Respirology and Infectious Diseases, Ottawa Hospital Research Institute, University of Ottawa, Ottawa Hospital, Ottawa, ON.
| | - Deborah D Van Dyk
- Department of Medicine, Division of Respirology and Infectious Diseases, Ottawa Hospital Research Institute, University of Ottawa, Ottawa Hospital, Ottawa, ON
| | - Marc Desjardlns
- Department of Laboratory Medicine, Eastern Ontario Regional Laboratories, Ottawa, ON
| | - Abdool S Yasseen
- Department of Medicine, Division of Respirology and Infectious Diseases, Ottawa Hospital Research Institute, University of Ottawa, Ottawa Hospital, Ottawa, ON
| | - Shawn D Aaron
- Department of Medicine, Division of Respirology and Infectious Diseases, Ottawa Hospital Research Institute, University of Ottawa, Ottawa Hospital, Ottawa, ON
| | - D William Cameron
- Department of Medicine, Division of Respirology and Infectious Diseases, Ottawa Hospital Research Institute, University of Ottawa, Ottawa Hospital, Ottawa, ON
| | | | - Maureen Baikie
- Department of Health, Government of Nunavut, Iqaluit, NU
| | - Smita Pakhale
- Department of Medicine, Division of Respirology and Infectious Diseases, Ottawa Hospital Research Institute, University of Ottawa, Ottawa Hospital, Ottawa, ON
| | - Claudla M Denklnger
- Respiratory Epidemiology and Clinical Research Unit and McGill International Tuberculosis Centre, McGill University, Montreal, QC, Canada
| | - Hojoon Sohn
- Respiratory Epidemiology and Clinical Research Unit and McGill International Tuberculosis Centre, McGill University, Montreal, QC, Canada
| | - Madhukar Pal
- Respiratory Epidemiology and Clinical Research Unit and McGill International Tuberculosis Centre, McGill University, Montreal, QC, Canada
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Fluctuating Behavior and Influential Factors in the Performance of the QuantiFERON-TB Gold In-Tube Assay in the Diagnosis of Tuberculosis. PLoS One 2015; 10:e0103763. [PMID: 26287382 PMCID: PMC4545827 DOI: 10.1371/journal.pone.0103763] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 07/01/2014] [Indexed: 01/08/2023] Open
Abstract
Background The QuantiFERON-TB Gold In-Tube (QFT-GIT) is a newly developed but widely used interferon-γ release assay for diagnosing tuberculosis (TB). However, research has not determined whether age or the use of an immune suppressive or anti-TB treatment influences this assay’s ability to detect TB. We assessed the QFT-GIT diagnostic performance for active tuberculosis (ATB) in children and adults in an endemic country and explored the effects of glucocorticoids and anti-TB therapy on the diagnostic value of the QFT-GIT. Methods A total of 60 children and 212 adults with suspected ATB were evaluated with the QFT-GIT. The association between the QFT-GIT diagnostic value and pretreatment factors was qualitatively and quantitatively assessed. Results The sensitivity of the QFT-GIT was 83.9% (95% CI 66.3%-94.6%) in children, and 73.7% (95% CI 57.8%-85.2%) in adults. Glucocorticoids affected the mitogen-stimulated response in both children and adults. In subjects undergoing glucocorticoid pretreatment, 25.0% of the children presented with false-negative QFT-GIT results, 28.6% of adults presented with indeterminate results. For subjects pre-treated with anti-TB drugs, 44.4% presented with false-negative QFT-GIT results. Conclusions The QFT-GIT has higher sensitivity and specificity in children than adults. Glucocorticoid treatment negatively impacts the diagnostic value of the QFT-GIT in all age groups. Anti-TB treatment decreases the sensitivity of the QFT-GIT. Therefore, we recommend that the QFT-GIT assay be performed before TB-specific treatment is initiated and the test should not be used on people undergoing immunosuppression treatment, regardless of their age. A quantitative analysis of the QFT-GIT could be useful for assessing and monitoring TB-specific and non-specific immunity during conversion of the disease.
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Denkinger CM, Kik SV, Cirillo DM, Casenghi M, Shinnick T, Weyer K, Gilpin C, Boehme CC, Schito M, Kimerling M, Pai M. Defining the needs for next generation assays for tuberculosis. J Infect Dis 2015; 211 Suppl 2:S29-38. [PMID: 25765104 DOI: 10.1093/infdis/jiu821] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
To accelerate the fight against tuberculosis, major diagnostic challenges need to be addressed urgently. Post-2015 targets are unlikely to be met without the use of novel diagnostics that are more accurate and can be used closer to where patients first seek care in affordable diagnostic algorithms. This article describes the efforts by the stakeholder community that led to the identification of the high-priority diagnostic needs in tuberculosis. Subsequently target product profiles for the high-priority diagnostic needs were developed and reviewed in a World Health Organization (WHO)-led consensus meeting. The high-priority diagnostic needs included (1) a sputum-based replacement test for smear-microscopy; (2) a non-sputum-based biomarker test for all forms of tuberculosis, ideally suitable for use at levels below microscopy centers; (3) a simple, low cost triage test for use by first-contact care providers as a rule-out test, ideally suitable for use by community health workers; and (4) a rapid drug susceptibility test for use at the microscopy center level. The developed target product profiles, along with complimentary work presented in this supplement, will help to facilitate the interaction between the tuberculosis community and the diagnostics industry with the goal to lead the way toward the post-2015 global tuberculosis targets.
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Affiliation(s)
- Claudia M Denkinger
- FIND, Geneva, Switzerland Division of Infectious Disease, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Sandra V Kik
- McGill International TB Centre and Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Canada
| | | | | | - Thomas Shinnick
- Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Karin Weyer
- World Health Organization, Geneva, Switzerland
| | | | | | - Marco Schito
- HJF-DAIDS, A division of The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland
| | | | - Madhukar Pai
- McGill International TB Centre and Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Canada
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Pinyopornpanish K, Chaiwarith R, Pantip C, Keawvichit R, Wongworapat K, Khamnoi P, Supparatpinyo K, Sirisanthana T. Comparison of Xpert MTB/RIF Assay and the Conventional Sputum Microscopy in Detecting Mycobacterium tuberculosis in Northern Thailand. Tuberc Res Treat 2015; 2015:571782. [PMID: 26064681 PMCID: PMC4430669 DOI: 10.1155/2015/571782] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 04/15/2015] [Indexed: 11/24/2022] Open
Abstract
Background. Despite low sensitivity in detection of Mycobacterium tuberculosis, sputum acid-fast smear remains the main diagnostic method. This study aimed to compare the diagnostic performance of Xpert MTB/RIF assay versus conventional sputum acid-fast smear. Materials and Methods. A cross-sectional study was conducted at Chiang Mai University Hospital, Thailand. Patients who were ≥15 years old and had clinically suspected pulmonary tuberculosis were included. Results. 109 specimens from 57 patients were included. Using MGIT sputum culture as a reference standard, the sensitivity (SEN) and specificity (SPEC) for Xpert were 95.3% (95% CI, 84.2%, 99.4%) and 86.4% (95% CI, 75.7%, 93.6%). The SEN and SPEC for sputum acid-fast smear were 60.5% (95% CI, 44.4%, 75.0%) and 98.5% (95% CI, 91.8%, 100%). Xpert had significantly higher sensitivity (p value < 0.001) and lower specificity (p value = 0.022) than sputum acid-fast smear. Among 43 culture-proven M. tuberculosis specimens, sensitivity of Xpert was 100% (95% CI, 86.7%, 100%) in acid-fast positive smears (n = 26) and 88.2% (95% CI, 63.5%, 98.5%) in acid-fast negative smears (n = 17). Conclusions. The good sensitivity and specificity of Xpert assay in detecting M. tuberculosis from sputum specimens may help in early diagnosis and treatment of pulmonary tuberculosis, particularly among patients who had acid-fast negative sputum smear.
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Affiliation(s)
- Kanokwan Pinyopornpanish
- Department of Medicine, Faculty of Medicine, Chiang Mai University, Muang, Chiang Mai 50200, Thailand
| | - Romanee Chaiwarith
- Department of Medicine, Faculty of Medicine, Chiang Mai University, Muang, Chiang Mai 50200, Thailand
| | - Chansom Pantip
- Research Institute for Health Sciences, Faculty of Medicine, Chiang Mai University, Muang, Chiang Mai 50200, Thailand
| | - Rassamee Keawvichit
- Research Institute for Health Sciences, Faculty of Medicine, Chiang Mai University, Muang, Chiang Mai 50200, Thailand
| | - Kanlaya Wongworapat
- Research Institute for Health Sciences, Faculty of Medicine, Chiang Mai University, Muang, Chiang Mai 50200, Thailand
| | - Phadungkiat Khamnoi
- Central Diagnostic Laboratory, Chiang Mai University Hospital, Muang, Chiang Mai 50200, Thailand
| | - Khuanchai Supparatpinyo
- Department of Medicine, Faculty of Medicine, Chiang Mai University, Muang, Chiang Mai 50200, Thailand
- Research Institute for Health Sciences, Faculty of Medicine, Chiang Mai University, Muang, Chiang Mai 50200, Thailand
| | - Thira Sirisanthana
- Research Institute for Health Sciences, Faculty of Medicine, Chiang Mai University, Muang, Chiang Mai 50200, Thailand
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Chaisson LH, Davis JL. Reply to Baker and Holtom. Clin Infect Dis 2015; 60:1288-9. [PMID: 25586685 DOI: 10.1093/cid/civ008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Lelia H Chaisson
- Division of Pulmonary and Critical Care Medicine Department of Medicine, San Francisco General Hospital, University of California
| | - J Lucian Davis
- Division of Pulmonary and Critical Care Medicine Curry International Tuberculosis Center Department of Medicine, San Francisco General Hospital, University of California
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Huh HJ, Jeong BH, Jeon K, Koh WJ, Ki CS, Lee NY. Performance evaluation of the Xpert MTB/RIF assay according to its clinical application. BMC Infect Dis 2014; 14:589. [PMID: 25395048 PMCID: PMC4247199 DOI: 10.1186/s12879-014-0589-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 10/24/2014] [Indexed: 01/20/2023] Open
Abstract
Background The Xpert MTB/RIF assay (Xpert assay; Cepheid, Sunnyvale, CA) is becoming the test of choice for the rapid diagnosis of tuberculosis and rifampin (RIF) resistance. The aim of this study was to evaluate the performance of the Xpert assay with respect to its clinical application at a tertiary care hospital in Korea, a country with an intermediate tuberculosis burden and high-resource. Methods A total of 303 Xpert assay results from 109 smear-positive and 194 smear-negative respiratory specimens were retrospectively reviewed. Based on patients’ medical records, four categories of clinical applications of the Xpert assay were identified: (1) the diagnosis of pulmonary tuberculosis in patients with a high probability of pulmonary tuberculosis according to their clinical and radiological features; (2) the exclusion of tuberculosis in clinically indeterminate patients for pulmonary tuberculosis; (3) the differentiation of Mycobacterium tuberculsosis (MTB) from nontuberculous mycobacteria in a smear-positive specimen; and (4) the diagnosis of RIF resistance. Standard culture and drug susceptibility tests were used as reference methods. Results The sensitivity of the Xpert assay for MTB detection in category 1 was 89.8% (95% confidence interval [CI], 78.5-95.8%), but 66.7% (95% CI, 12.5-98.2%) in category 2. The positive predictive values ranged from 33.3% (95% CI, 6.0-75.9%) in category 2 to 91.3% and 91.7% in categories 1 and 3, respectively. The negative predictive values were over 90% in all categories. The Xpert assay correctly detected RIF resistance in six of the seven (85.7%) isolates tested. Conclusions The Xpert assay exhibited variable performance according to its clinical application; this finding cautions that careful interpretation for the results of this assay would be needed according to its intended purpose. Electronic supplementary material The online version of this article (doi:10.1186/s12879-014-0589-x) contains supplementary material, which is available to authorized users.
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Shinnick TM, Starks AM, Alexander HL, Castro KG. Evaluation of the Cepheid Xpert MTB/RIF assay. Expert Rev Mol Diagn 2014; 15:9-22. [PMID: 25373876 DOI: 10.1586/14737159.2015.976556] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The lack of capacity to provide laboratory confirmation of a diagnosis of tuberculosis disease (TB) is contributing to enormous gaps in the ability to find, treat and follow TB patients. WHO estimates that globally only about 57% of the notified new cases of pulmonary TB in 2012 and about 19% of rifampicin-resistant TB cases were laboratory confirmed. The Cepheid Xpert(®) MTB/RIF assay has been credited with revolutionizing laboratory testing to aid in the diagnosis of TB and rifampicin-resistant TB. This semi-automated test can detect both the causative agent of TB and mutations that confer rifampicin resistance from clinical specimens within 2 h after starting the test. In this article, we review the performance of the test, its pathway to regulatory approval and endorsement, guidelines for its use and lessons learned from the implementation of the test in low-burden, high-resource countries and in high-burden, low-resource countries.
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Affiliation(s)
- Thomas M Shinnick
- Division of Tuberculosis Elimination, National Center for HIV, Viral Hepatitis, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA, USA 30333
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El Sahly HM. Performance of Xpert MTB/RIF in Induced Sputum Samples at Detecting Mycobacterium Tuberculosis. Clin Infect Dis 2014; 59:911-2. [DOI: 10.1093/cid/ciu375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Denkinger CM, Pai M. Reply to El Sahly. Clin Infect Dis 2014; 59:912. [PMID: 24855148 DOI: 10.1093/cid/ciu376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Claudia M Denkinger
- McGill International Tuberculosis Centre and Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Canada Division of Infectious Disease, Beth Israel Deaconess Medical Centre, Boston, Massachusetts
| | - Madhukar Pai
- McGill International Tuberculosis Centre and Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Canada Respiratory Epidemiology and Clinical Research Unit, Montreal Chest Institute, Montreal, Canada
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Davis JL, Kawamura LM, Chaisson LH, Grinsdale J, Benhammou J, Ho C, Babst A, Banouvong H, Metcalfe JZ, Pandori M, Hopewell PC, Cattamanchi A. Impact of GeneXpert MTB/RIF on patients and tuberculosis programs in a low-burden setting. a hypothetical trial. Am J Respir Crit Care Med 2014; 189:1551-9. [PMID: 24869625 DOI: 10.1164/rccm.201311-1974oc] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
RATIONALE Guidelines recommend routine nucleic-acid amplification testing in patients with presumed tuberculosis (TB), but these tests have not been widely adopted. GeneXpert MTB/RIF (Xpert), a novel, semiautomated TB nucleic-acid amplification test, has renewed interest in this technology, but data from low-burden countries are limited. OBJECTIVES We sought to estimate Xpert's potential clinical and public health impact on empiric treatment, contact investigation, and housing in patients undergoing TB evaluation. METHODS We performed a prospective, cross-sectional study with 2-month follow-up comparing Xpert with standard strategies for evaluating outpatients for active pulmonary TB at the San Francisco Department of Public Health TB Clinic between May 2010 and June 2011. We calculated the diagnostic accuracy of standard algorithms for initial empiric TB treatment, contact investigation, and housing in reference to three Mycobacterium tuberculosis sputum cultures, as compared with that of a single sputum Xpert test. We estimated the incremental diagnostic value of Xpert, and the hypothetical reductions in unnecessary treatment, contact investigation, and housing if Xpert were adopted to guide management decisions. MEASUREMENTS AND MAIN RESULTS A total of 156 patients underwent Xpert testing. Fifty-nine (38%) received empiric TB treatment. Thirteen (8%) had culture-positive TB. Xpert-guided management would have hypothetically decreased overtreatment by 94%, eliminating a median of 44 overtreatment days (interquartile range, 43-47) per patient and 2,169 total overtreatment days (95% confidence interval, 1,938-2,400) annually, without reducing early detection of TB patients. We projected similar benefits for contact investigation and housing. CONCLUSIONS Xpert could greatly reduce the frequency and impact of unnecessary empiric treatment, contact investigation, and housing, providing substantial patient and programmatic benefits if used in management decisions.
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Johnson DH, Via LE, Kim P, Laddy D, Lau CY, Weinstein EA, Jain S. Nuclear imaging: a powerful novel approach for tuberculosis. Nucl Med Biol 2014; 41:777-84. [PMID: 25195017 DOI: 10.1016/j.nucmedbio.2014.08.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 07/16/2014] [Accepted: 08/03/2014] [Indexed: 02/06/2023]
Abstract
Nearly 20 years after the World Health Organization declared tuberculosis (TB) a global public health emergency, TB still remains a major global threat with 8.6 million new cases and 1.3 million deaths annually. Mycobacterium tuberculosis adapts to a quiescent physiological state, and is notable for complex interaction with the host, producing poorly-understood disease states ranging from latent infection to fully active disease. Of the approximately 2.5 billion people latently infected with M. tuberculosis, many will develop reactivation disease (relapse), years after the initial infection. While progress has been made on some fronts, the alarming spread of multidrug-resistant, extensively drug-resistant, and more recently totally-drug resistant strains is of grave concern. New tools are urgently needed for rapidly diagnosing TB, monitoring TB treatments and to allow unique insights into disease pathogenesis. Nuclear bioimaging is a powerful, noninvasive tool that can rapidly provide three-dimensional views of disease processes deep within the body and conduct noninvasive longitudinal assessments of the same patient. In this review, we discuss the application of nuclear bioimaging to TB, including the current state of the field, considerations for radioprobe development, study of TB drug pharmacokinetics in infected tissues, and areas of research and clinical needs that could be addressed by nuclear bioimaging. These technologies are an emerging field of research, overcome several fundamental limitations of current tools, and will have a broad impact on both basic research and patient care. Beyond diagnosis and monitoring disease, these technologies will also allow unique insights into understanding disease pathogenesis; and expedite bench-to-bedside translation of new therapeutics. Finally, since molecular imaging is readily available for humans, validated tracers will become valuable tools for clinical applications.
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Affiliation(s)
| | | | | | | | | | | | - Sanjay Jain
- Center for Infection and Inflammation Imaging Research, Center for Tuberculosis Research and Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD
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Lippincott CK, Miller MB, Popowitch EB, Hanrahan CF, Van Rie A. Xpert MTB/RIF assay shortens airborne isolation for hospitalized patients with presumptive tuberculosis in the United States. Clin Infect Dis 2014; 59:186-92. [PMID: 24729506 PMCID: PMC4133562 DOI: 10.1093/cid/ciu212] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 02/28/2014] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND In the United States, individuals with presumptive pulmonary tuberculosis are placed in airborne infection isolation (AII) and assessed by smear microscopy on 3 respiratory specimens collected 8-24 hours apart. Xpert MTB/RIF assay (Xpert) on 1, 2, or 3 specimens may be more efficient for determining AII discontinuation. METHODS This single-center, observational cohort study of inpatients with presumptive pulmonary tuberculosis enrolled adults with 1 or more sputum specimens submitted for smear microscopy. Smear microscopy and Xpert were performed on each sputum specimen. Clinicians were blinded to Xpert results. The primary endpoint was AII duration. Secondary endpoints were laboratory processing time, strategy-based tuberculosis detection, and sensitivity and specificity. RESULTS Among 207 subjects, the median AII duration was 68.0 hours (interquartile range [IQR], 47.1-97.5) for smear microscopy compared with 20.8 hours (IQR, 16.8-32.0) for the 1-specimen Xpert, 41.2 hours (IQR, 26.6-54.8) for the 2-specimen Xpert, and 54.0 hours (IQR, 43.3-80.0) for the 3-specimen Xpert strategies (P ≤ .004). Median laboratory processing time for smear microscopy was 2.5 times as long as Xpert (P < .001). The 2- and 3-specimen Xpert and smear microscopy strategies captured all 6 tuberculosis cases. The 1-specimen Xpert strategy missed 1 case. No difference was observed between smear microscopy and Xpert in sensitivity or specificity for detection of Mycobacterium tuberculosis. CONCLUSIONS Xpert-based strategies significantly reduced AII duration compared with the smear-based strategy. The 2-specimen Xpert strategy was most efficient in minimizing AII time while identifying all tuberculosis cases among individuals with presumptive tuberculosis in this low-burden setting.
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Affiliation(s)
| | - Melissa B Miller
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill
| | - Elena B Popowitch
- Clinical Microbiology/Immunology Laboratories, University of North Carolina Health Care, Chapel Hill
| | | | - Annelies Van Rie
- Department of Epidemiology, University of North Carolina at Chapel Hill
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Salfinger M. Molecular laboratory testing for tuberculosis: innovators, early adopters, or laggards? Clin Infect Dis 2014; 58:977-9. [PMID: 24429435 DOI: 10.1093/cid/ciu024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Max Salfinger
- Department of Medicine, National Jewish Health, Denver, Colorado
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