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Kanade S, Mohammed Z, Kulkarni A, Nataraj G. Comparison of xpert MTB/RIF assay, line probe assay, and culture in diagnosis of pulmonary tuberculosis on bronchoscopic specimen. Int J Mycobacteriol 2023; 12:151-156. [PMID: 37338476 DOI: 10.4103/ijmy.ijmy_86_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2023] Open
Abstract
Background In patients unable to expectorate good quality sputum or with minimal to none sputum production, bronchoscopic specimens may be collected. The objective of the study is to determine the use of Xpert MTB/RIF assay and line probe assay (LPA) in the diagnosis of pulmonary TB (PTB) using specimens collected by bronchoscopy in a tertiary care center. Methods Bronchoscopy specimens received in the TB laboratory were processed by microscopy, Xpert MTB/RIF assay, LPA, and mycobacteria growth indicator tube (MGIT) culture. Results of MGIT culture are considered gold standard. Results Of the 173 specimens tested, MTB was detected in 48 (27.74%) samples by any of the above methods. Positivity in bronchoalveolar lavage was 31.4% (44/140) and in bronchial wash was 12.1% (4/33). Detection by microscopy, Xpert assay, and culture was 20 (11.56%), 45 (26.01%), and 38 (21.96%), respectively. Culture detected MTB in three additional specimens compared to Xpert assay. Xpert assay detected MTB in 45 (26%) specimens which include 10 specimens which were negative by culture. LPA detected MTB in 18 (90%) out of 20 smear-positive specimens. RIF resistance was detected in 20 (41.7%) specimens by Xpert and/or MGIT culture drug susceptibility testing (DST). Isoniazid (INH) resistance was detected in 19 specimens by LPA and MGIT culture DST. Conclusion Bronchoscopy can provide alternative respiratory specimens for diagnosing PTB in patients with difficulty to expectorate sputum. The utility of Xpert MTB/RIF as a rapid, sensitive, and specific test should always be supplemented with culture in difficult-to-obtain and precious respiratory specimens. LPA plays an important role in rapid detection of INH monoresistance.
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Affiliation(s)
- Swapna Kanade
- Department of Microbiology, Seth G.S. Medical College and KEM Hospital, Mumbai, Maharashtra, India
| | - Zakiuddin Mohammed
- Department of Microbiology, Seth G.S. Medical College and KEM Hospital, Mumbai, Maharashtra; Telangana Diagnostics Central Laboratory, Hyderabad, Telangana, India
| | - Anisha Kulkarni
- Department of Microbiology, Seth G.S. Medical College and KEM Hospital, Mumbai, Maharashtra, India
| | - Gita Nataraj
- Department of Microbiology, Seth G.S. Medical College and KEM Hospital, Mumbai, Maharashtra, India
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Karuniawati A, Burhan E, Koendhori EB, Sari D, Haryanto B, Nuryastuti T, Gayatri AAAY, Bahrun U, Kusumawati RL, Sugiyono RI, Susanto NH, Diana A, Kosasih H, Naysilla AM, Lokida D, Neal A, Siddiqui S, Lau CY, Karyana M. Performance of Xpert MTB/RIF and sputum microscopy compared to sputum culture for diagnosis of tuberculosis in seven hospitals in Indonesia. Front Med (Lausanne) 2023; 9:909198. [PMID: 36743681 PMCID: PMC9896521 DOI: 10.3389/fmed.2022.909198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 12/07/2022] [Indexed: 01/21/2023] Open
Abstract
Introduction Tuberculosis (TB) is a major public health concern in Indonesia, where the incidence was 301 cases per 100,000 inhabitants in 2020 and the prevalence of multi-drug resistant (MDR) TB is increasing. Diagnostic testing approaches vary across Indonesia due to resource limitations. Acid-fast bacilli (AFB) smear is widely used, though Xpert MTB/RIF has been the preferred assay for detecting TB and rifampicin resistance since 2012 due to higher sensitivity and ability to rapidly identify rifampicin resistance. However, <1,000 Xpert instruments were available in Indonesia as of 2020 and the Xpert supply chain has suffered interruptions. Methods We compared the performance of Xpert MTB/RIF and AFB smear to facilitate optimization of TB case identification. We analyzed baseline data from a cohort study of adults with pulmonary TB conducted at seven hospitals across Indonesia. We evaluated sensitivity and specificity of AFB smear and Xpert MTB/RIF using Mycobacterium tuberculosis (Mtb) culture as the gold standard, factors associated with assay results, and consistency of Xpert MTB/RIF with drug susceptibility test (DST) in detecting rifampicin resistance. Results Sensitivity of AFB smear was significantly lower than Xpert MTB/RIF (86.2 vs. 97.4%, p-value <0.001), but specificity was significantly better (86.7 vs. 73.3%, p-value <0.001). Performance varied by hospital. Positivity rate for AFB smear and Mtb culture was higher in subjects with pulmonary cavities and in morning sputum samples. Consistency of Xpert MTB/RIF with DST was lower in those with rifampicin- sensitive TB by DST. Discussion Additional evaluation using sputa from primary and secondary Indonesian health centers will increase the generalizability of the assessment of AFB smear and Xpert MTB/RIF performance, and better inform health policy. Clinical trial registration [https://clinicaltrials.gov/], identifier [NCT027 58236].
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Affiliation(s)
- Anis Karuniawati
- Department of Microbiology, Faculty of Medicine, Universitas Indonesia, Dr. Cipto Mangunkusumo Hospital, Jakarta, Indonesia
| | - Erlina Burhan
- Department of Pulmonary and Respiratory Medicine, Faculty of Medicine, Universitas Indonesia, Persahabatan Hospital, Jakarta, Indonesia
| | - Eko Budi Koendhori
- Department of Medical Microbiology, Faculty of Medicine, Universitas Airlangga, Dr. Soetomo Hospital, Surabaya, Indonesia
| | - Desvita Sari
- Department of Microbiology, Faculty of Medicine, Universitas Diponegoro, Dr. Kariadi Hospital, Semarang, Indonesia
| | - Budi Haryanto
- Microbiology Unit, Persahabatan Hospital, Jakarta, Indonesia
| | - Titik Nuryastuti
- Department of Microbiology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - A. A. A. Yuli Gayatri
- Department of Internal Medicine, Faculty of Medicine, Universitas Udayana, Prof. IGNG. Ngoerah General Hospital, Bali, Indonesia
| | - Uleng Bahrun
- Department of Clinical Pathology, Faculty of Medicine, University of Hasanuddin, Dr. Wahidin Sudirohusodo Hospital, Makassar, Indonesia
| | - R. Lia Kusumawati
- Department of Microbiology, Faculty of Medicine, Universitas Sumatera Utara, H. Adam Malik General Hospital, Medan, Indonesia
| | - Retna Indah Sugiyono
- Indonesia Research Partnership on Infectious Disease (INA-RESPOND), Jakarta, Indonesia
| | - Nugroho Harry Susanto
- Indonesia Research Partnership on Infectious Disease (INA-RESPOND), Jakarta, Indonesia
| | - Aly Diana
- Indonesia Research Partnership on Infectious Disease (INA-RESPOND), Jakarta, Indonesia,Department of Public Health, Faculty of Medicine, Universitas Padjadjaran, Sumedang, Indonesia
| | - Herman Kosasih
- Indonesia Research Partnership on Infectious Disease (INA-RESPOND), Jakarta, Indonesia,*Correspondence: Herman Kosasih,
| | | | - Dewi Lokida
- Department of Clinical Pathology, Tangerang District Hospital, Tangerang, Indonesia
| | - Aaron Neal
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Sophia Siddiqui
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Chuen-Yen Lau
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Muhammad Karyana
- National Institute of Health Research and Development, Ministry of Health, Republic of Indonesia, Jakarta, Indonesia
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Sharma G, Malhotra B, John PJ, Gautam S, Bhargava S. Evaluation of GeneXpert and liquid culture for detection of Mycobacterium tuberculosis in pediatric patients. Indian J Med Microbiol 2022; 40:547-551. [PMID: 35985872 DOI: 10.1016/j.ijmmb.2022.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 07/15/2022] [Accepted: 07/16/2022] [Indexed: 11/05/2022]
Abstract
PURPOSE Evaluation of GeneXpert in comparison to liquid culture using Mycobacteria Growth Indicator Tube (MGIT) as gold standard for detection of Mycobacterium tuberculosis (MTB) in children. METHODS A total of 8123 samples, both pulmonary (5830) and extra pulmonary (2293) received from pediatric patients were processed for Acid Fast Bacilli (AFB) smear, GeneXpert and MGIT culture simultaneously. RESULTS Out of 8123 samples, 493 (6.1%) samples were found positive by GeneXpert and 508 (6.2%) samples by MGIT culture, 371 (4.6%) were found positive by both GeneXpert and MGIT culture. MGIT detected 137 (1.7%) extra positive than GeneXpert while GeneXpert detected 122 (1.5%) extra samples more positive than by MGIT. Sensitivity of GeneXpert was 73% and concordance between both methods was 96.8%. Rifampicin resistance was found in 49 (9.9%) samples among MTB positive by GeneXpert. Turnaround time for GeneXpert was approx. 2 h and for MGIT, it was 12-28 days. CONCLUSION Good sensitivity (73%) and concordance (96.8%) were observed for GeneXpert against MGIT culture in this study. GeneXpert can simultaneously detect MTB and rifampicin resistance in less than 2 h while MGIT takes 12-28 days for MTB detection only.
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Affiliation(s)
- Gaurav Sharma
- Department of Microbiology and Immunology, SMS Medical College, Jaipur, Rajasthan, India; Department of Zoology, University of Rajasthan, Jaipur, Rajasthan, India.
| | - Bharti Malhotra
- Department of Microbiology and Immunology, SMS Medical College, Jaipur, Rajasthan, India.
| | - P J John
- Department of Zoology, University of Rajasthan, Jaipur, Rajasthan, India.
| | - Swati Gautam
- Department of Microbiology and Immunology, SMS Medical College, Jaipur, Rajasthan, India.
| | - Shipra Bhargava
- International Centre for Excellence in Laboratory Training (ICELT), National Tuberculosis Institute, Bengaluru, India.
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Yusoof KA, García JI, Schami A, Garcia-Vilanova A, Kelley HV, Wang SH, Rendon A, Restrepo BI, Yotebieng M, Torrelles JB. Tuberculosis Phenotypic and Genotypic Drug Susceptibility Testing and Immunodiagnostics: A Review. Front Immunol 2022; 13:870768. [PMID: 35874762 PMCID: PMC9301132 DOI: 10.3389/fimmu.2022.870768] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 06/06/2022] [Indexed: 12/24/2022] Open
Abstract
Tuberculosis (TB), considered an ancient disease, is still killing one person every 21 seconds. Diagnosis of Mycobacterium tuberculosis (M.tb) still has many challenges, especially in low and middle-income countries with high burden disease rates. Over the last two decades, the amount of drug-resistant (DR)-TB cases has been increasing, from mono-resistant (mainly for isoniazid or rifampicin resistance) to extremely drug resistant TB. DR-TB is problematic to diagnose and treat, and thus, needs more resources to manage it. Together with+ TB clinical symptoms, phenotypic and genotypic diagnosis of TB includes a series of tests that can be used on different specimens to determine if a person has TB, as well as if the M.tb strain+ causing the disease is drug susceptible or resistant. Here, we review and discuss advantages and disadvantages of phenotypic vs. genotypic drug susceptibility testing for DR-TB, advances in TB immunodiagnostics, and propose a call to improve deployable and low-cost TB diagnostic tests to control the DR-TB burden, especially in light of the increase of the global burden of bacterial antimicrobial resistance, and the potentially long term impact of the coronavirus disease 2019 (COVID-19) disruption on TB programs.
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Affiliation(s)
- Kizil A. Yusoof
- Graduate School of Biomedical Sciences, University of Texas Health San Antonio, San Antonio, TX, United States
| | - Juan Ignacio García
- Population Health Program, Tuberculosis Group, Texas Biomedical Research Institute, San Antonio, TX, United States
- *Correspondence: Juan Ignacio García, ; Blanca I. Restrepo, ; Marcel Yotebieng, ; Jordi B. Torrelles,
| | - Alyssa Schami
- Graduate School of Biomedical Sciences, University of Texas Health San Antonio, San Antonio, TX, United States
- Population Health Program, Tuberculosis Group, Texas Biomedical Research Institute, San Antonio, TX, United States
| | - Andreu Garcia-Vilanova
- Population Health Program, Tuberculosis Group, Texas Biomedical Research Institute, San Antonio, TX, United States
| | - Holden V. Kelley
- Population Health Program, Tuberculosis Group, Texas Biomedical Research Institute, San Antonio, TX, United States
| | - Shu-Hua Wang
- Department of Internal Medicine, Division of Infectious Diseases, College of Medicine and Global One Health Initiative, The Ohio State University, Columbus, OH, United States
| | - Adrian Rendon
- Centro de Investigación, Prevención y Tratamiento de Infecciones Respiratorias (CIPTIR), Hospital Universitario de Monterrey Universidad Autónoma de Nuevo León (UANL), Monterrey, Mexico
| | - Blanca I. Restrepo
- School of Public Health, University of Texas Health Science Center at Houston, Brownsville, TX, United States
- School of Medicine, South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley, Edinburg, TX, United States
- *Correspondence: Juan Ignacio García, ; Blanca I. Restrepo, ; Marcel Yotebieng, ; Jordi B. Torrelles,
| | - Marcel Yotebieng
- Division of General Internal Medicine, Department of Medicine, Albert Einstein College of Medicine, New York City, NY, United States
- *Correspondence: Juan Ignacio García, ; Blanca I. Restrepo, ; Marcel Yotebieng, ; Jordi B. Torrelles,
| | - Jordi B. Torrelles
- Graduate School of Biomedical Sciences, University of Texas Health San Antonio, San Antonio, TX, United States
- Population Health Program, Tuberculosis Group, Texas Biomedical Research Institute, San Antonio, TX, United States
- *Correspondence: Juan Ignacio García, ; Blanca I. Restrepo, ; Marcel Yotebieng, ; Jordi B. Torrelles,
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Mbelele PM, Sabiiti W, Heysell SK, Sauli E, Mpolya EA, Mfinanga S, Gillespie SH, Addo KK, Kibiki G, Sloan DJ, Mpagama SG. Use of a molecular bacterial load assay to distinguish between active TB and post-TB lung disease. Int J Tuberc Lung Dis 2022; 26:276-278. [PMID: 35197168 PMCID: PMC8886960 DOI: 10.5588/ijtld.21.0459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- P M Mbelele
- Kibong´oto Infectious Diseases Hospital, Sanya Juu, Siha, Kilimanjaro, Tanzania, Department of Global Health and Biomedical Sciences, School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology (NM-AIST), Arusha, Tanzania
| | - W Sabiiti
- Division of Infection and Global Health, School of Medicine, University of St Andrews, St Andrews, Scotland, UK
| | - S K Heysell
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA
| | - E Sauli
- Department of Global Health and Biomedical Sciences, School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology (NM-AIST), Arusha, Tanzania
| | - E A Mpolya
- Department of Global Health and Biomedical Sciences, School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology (NM-AIST), Arusha, Tanzania
| | - S Mfinanga
- Department of Global Health and Biomedical Sciences, School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology (NM-AIST), Arusha, Tanzania, National Institute for Medical Research (NIMR), Muhimbili Center, Dar es salaam, Tanzania
| | - S H Gillespie
- Division of Infection and Global Health, School of Medicine, University of St Andrews, St Andrews, Scotland, UK
| | - K K Addo
- Department of Bacteriology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - G Kibiki
- Kibong´oto Infectious Diseases Hospital, Sanya Juu, Siha, Kilimanjaro, Tanzania, East African Health Research Commission (EAHRC), Bujumbura, Burundi
| | - D J Sloan
- Division of Infection and Global Health, School of Medicine, University of St Andrews, St Andrews, Scotland, UK
| | - S G Mpagama
- Kibong´oto Infectious Diseases Hospital, Sanya Juu, Siha, Kilimanjaro, Tanzania, Department of Global Health and Biomedical Sciences, School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology (NM-AIST), Arusha, Tanzania
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Jafari C, Olaru ID, Daduna F, Lange C, Kalsdorf B. Rapid Diagnosis of Recurrent Paucibacillary Tuberculosis. Pathog Immun 2022; 7:189-202. [PMID: 37207169 PMCID: PMC10189871 DOI: 10.20411/pai.v7i2.565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 03/20/2023] [Indexed: 05/21/2023] Open
Abstract
Introduction The rapid diagnosis of tuberculosis recurrence can be challenging due to persistently positive detection of Mycobacterium tuberculosis-specific DNA from sputum and bronchopulmonary samples in the absence of active disease. Methods We compared the diagnostic accuracy of the detection of M. tuberculosis-specific DNA by either Xpert (January 2010-June 2018) or Xpert Ultra (July 2018-June 2020) and M. tuberculosis-specific ELISPOT in bronchoalveolar lavage (BAL) samples with M. tuberculosis culture results from sputum or bronchopulmonary samples in patients with suspected recurrence of pulmonary tuberculosis. Results Among 44 individuals with previous tuberculosis and a presumptive diagnosis of recurrent pulmonary tuberculosis, 4/44 (9.1%) were diagnosed with recurrent tuberculosis by culture. DNA of M. tuberculosis was detected by Xpert in BAL fluid in 1/4 (25%) individuals with recurrent tuberculosis and in 2/40 (5%) cases with past tuberculosis without recurrence, while BAL-ELISPOT with a cut-off of >4,000 early secretory antigenic target-6-specific or culture filtrate protein-10-specific interferon-γ-producing lymphocytes per 1 million BAL-lymphocytes was positive in 4/4 (100%) individuals with recurrent tuberculosis and in 2/40 (5%) cases of past tuberculosis without recurrence. Conclusion M. tuberculosis-specific BAL-ELISPOT is more accurate than BAL-Xpert for the diagnosis of paucibacillary tuberculosis recurrence.
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Affiliation(s)
- Claudia Jafari
- Division of Clinical Infectious Diseases, Research Center Borstel, Borstel, Germany
| | - Ioana D Olaru
- Division of Clinical Infectious Diseases, Research Center Borstel, Borstel, Germany
- London School of Hygiene and Tropical Medicine, London, United Kingdom
- Institute of Medical Microbiology, University of Münster, Münster, Germany
| | - Franziska Daduna
- Division of Clinical Infectious Diseases, Research Center Borstel, Borstel, Germany
| | - Christoph Lange
- Division of Clinical Infectious Diseases, Research Center Borstel, Borstel, Germany
- Respiratory Medicine & International Health, University of Lübeck, Lübeck, Germany
- German Center for Infection Research (DZIF), Partner site Hamburg-Lübeck-Borstel, Germany
- Baylor College of Medicine and Texas Children's Hospital, Houston, Texas
| | - Barbara Kalsdorf
- Division of Clinical Infectious Diseases, Research Center Borstel, Borstel, Germany
- Respiratory Medicine & International Health, University of Lübeck, Lübeck, Germany
- German Center for Infection Research (DZIF), Partner site Hamburg-Lübeck-Borstel, Germany
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7
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Bai W, Liu L, Wu L, Chen S, Wu S, Wang Z, Xu K, Chi Q, Pan Y, Xu X. Assessing the utility of the Xpert Mycobacterium tuberculosis/rifampin assay for analysis of bronchoalveolar lavage fluid in patients with suspected pulmonary tuberculosis. J Clin Lab Anal 2021; 36:e24154. [PMID: 34850984 PMCID: PMC8761447 DOI: 10.1002/jcla.24154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 11/09/2021] [Accepted: 11/17/2021] [Indexed: 11/20/2022] Open
Abstract
Background There is limited research assessing the utility of the Xpert Mycobacterium tuberculosis/rifampin (MTB/RIF) assay for the analysis of bronchoalveolar lavage fluid (BALF) in Chinese patients with suspected pulmonary tuberculosis (PTB). Thus, our objective was to determine the diagnostic accuracy of the Xpert MTB/RIF assay and evaluate its utility for the determination of rifampicin resistance. Methods We retrospectively analyzed BALF from 214 patients with suspected PTB between January 2018 and March 2019. Using mycobacterial culture or final clinical diagnosis as the reference standard, the diagnostic accuracy of the smear microscopy (SM), tuberculosis bacillus DNA (TB‐DNA), Xpert MTB/RIF assay, and the determination of rifampicin resistance based on the Xpert MTB/RIF assay were compared. Results As compared to mycobacterial culture, the sensitivity of the Xpert MTB/RIF assay, SM, and TB‐DNA were 85.5% (74.2%–93.1%), 38.7% (26.6%–51.9%), and 67.7% (54.7%–79.1%), respectively. As compared to the final diagnosis, the specificity of the Xpert MTB/RIF assay, SM, and TB‐DNA were 100.0% (95.9%–100.0%), 94.3% (87.1%–98.1%), and 98.9% (93.8%–100.0%), respectively. The sensitivity and specificity of the rifampicin resistance detection using the Xpert MTB/RIF assay were 100% and 98.0%, respectively, with liquid culture as the reference. Conclusions This study demonstrates that the analysis of BALF with the Xpert MTB/RIF assay provides a rapid and accurate tool for the early diagnosis of PTB. The accuracy of diagnosis was superior compared with the SM and TB‐DNA. Moreover, Xpert is a quick and accurate method for the diagnosis of rifampicin‐resistant tuberculosis and can also provide more effective guidance for the treatment of PTB or multidrug‐resistant tuberculosis (MDR‐TB).
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Affiliation(s)
- Wenjing Bai
- Department of Clinical Laboratory Medicine, Wenzhou Central Hospital, Wenzhou, China
| | - Lingling Liu
- Department of Clinical Laboratory Medicine, Wenzhou Longwan First People's Hospital, Wenzhou, China
| | - Lianpeng Wu
- Department of Clinical Laboratory Medicine, Wenzhou Central Hospital, Wenzhou, China
| | - Shanshan Chen
- Department of Blood Transfusion, People's Hospital of Pingyang County, Wenzhou, China
| | - Shuangliao Wu
- Department of Clinical Laboratory Medicine, Wenzhou Central Hospital, Wenzhou, China
| | - Zhihui Wang
- Department of Obstetrics and Gynecology, Wenzhou Central Hospital, Wenzhou, China
| | - Ke Xu
- Department of Clinical Laboratory Medicine, Wenzhou Central Hospital, Wenzhou, China
| | - Qiong Chi
- Department of Respiratory and Critical Care Medicine, Key Laboratory of precision medicine of Wenzhou, Wenzhou Central Hospital, Wenzhou, China
| | - Yong Pan
- Department of Clinical Laboratory Medicine, Key Laboratory of precision medicine of Wenzhou, Wenzhou Central Hospital, Wenzhou, China
| | - Xueqin Xu
- Department of Clinical Laboratory Medicine, Key Laboratory of precision medicine of Wenzhou, Wenzhou Central Hospital, Wenzhou, China
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Performance of Xpert MTB/RIF Ultra for diagnosis of pulmonary and extra-pulmonary tuberculosis, one year of use in a multi-centric hospital laboratory in Brussels, Belgium. PLoS One 2021; 16:e0249734. [PMID: 33831077 PMCID: PMC8031447 DOI: 10.1371/journal.pone.0249734] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 03/23/2021] [Indexed: 02/07/2023] Open
Abstract
Among the challenges in controlling tuberculosis, a rapid and accurate diagnostic test for the detection of Mycobacterium tuberculosis complex (MTBc) and its resistance to first line therapies is crucial. We evaluated the performance of the Xpert MTB/RIF Ultra assay (Xpert Ultra) for the rapid detection of MTBc and rifampicin resistance (RR) in 1120 pulmonary and 461 extra-pulmonary clinical specimens and compared it with conventional phenotypic techniques. The Xpert Ultra assay detected MTBc in 223 (14.1%) samples with an overall sensitivity and specificity, using culture as the "gold standard", of 91.1% (95% CI, 85.6-95.1) and 94.5% (95% CI, 93.1-95.6), respectively. The sensitivity of the Xpert Ultra test for smear-negative extra-pulmonary specimens was high (87.1%), even higher than with smear-negative pulmonary specimens (81.8%). But this enhanced sensitivity came with a low overall specificity of smear-negative extra-pulmonary specimens (66.7%). For 73 patients, 79/1423 (3.4%) negative mycobacterial culture samples were found to be positive with Xpert Ultra. Clinical data was necessary to correctly interpret potential false-positive results, especially trace-positive results. Sensitivity of the Xpert Ultra to detect RR compared to drug susceptibility testing was 100% (95% CI, 29.2-100) and specificity was 99.2% (95% CI, 95.8-100). We concluded that the Xpert Ultra test is able to provide a reliable TB diagnosis within a significantly shorter turnaround time than culture. This is especially true for paucibacillary samples such as smear-negative pulmonary specimens and extra-pulmonary specimens.
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9
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Tomaz APDO, Raboni SM, Kussen GMB, da Silva Nogueira K, Lopes Ribeiro CE, Costa LMD. The Xpert® MTB/RIF diagnostic test for pulmonary and extrapulmonary tuberculosis in immunocompetent and immunocompromised patients: Benefits and experiences over 2 years in different clinical contexts. PLoS One 2021; 16:e0247185. [PMID: 33657113 PMCID: PMC7928506 DOI: 10.1371/journal.pone.0247185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 02/02/2021] [Indexed: 11/19/2022] Open
Abstract
Xpert® MTB/RIF has been widely used for tuberculosis (TB) diagnosis in Brazil, since 2014. This prospective observational study aimed to evaluate the performance of Xpert in different contexts during a two-year period: (i) laboratory and clinical/epidemiological diagnosis; (ii) HIV-positive and -negative populations; (iii) type of specimens: pulmonary and extrapulmonary. Overall, 924 specimens from 743 patients were evaluated. The performance of the assays was evaluated considering culture (Lowenstein Jensen or LJ medium) results and composite reference standard (CRS) classification as gold standard. According to CRS evaluation, 219 cases (29.5%) were classified as positive cases, 157 (21.1%) as ‘possible TB’, and 367 (49.3%) as ‘not TB’. Based on culture, Xpert and AFB smear achieved a sensitivity of 96% and 62%, respectively, while based on CRS, the sensitivities of Xpert, AFB smear, and culture were 40.7%, 20%, and 25%, respectively. The pooled sensitivity and specificity of Xpert were 96% and 94%, respectively. Metric evaluations were similar between pulmonary and extrapulmonary samples against culture, whereas compared to CRS, the sensitivities were 44.6% and 29.3% for the pulmonary and extrapulmonary cases, respectively. The Xpert detected 42/69 (60.9%) patients with confirmed TB and negative culture on LJ medium, and 52/69 (75.4%) patients with negative AFB smear results. There was no significant difference in the diagnostic accuracy based on the types of specimens and population (positive- and negative-HIV). Molecular testing detected 13 cases of TB in culture-negative patients with severe immunosuppression. Resistance to rifampicin was detected in seven samples. Herein, Xpert showed improved detection of pulmonary and extrapulmonary TB cases, both among HIV-positive and -negative patients, even in cases with advanced immunosuppression, thereby performing better than multiple other diagnostic parameters.
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Affiliation(s)
- Ana Paula de Oliveira Tomaz
- Programa de Pós graduação em Biotecnologia Aplicada à Saúde da Criança e do Adolescente da Faculdades Pequeno Príncipe (FPP), Instituto de Pesquisa Pelé Pequeno Príncipe (IPPPP), Curitiba, Paraná, Brasil
- Complexo Hospital de Clínicas, Universidade Federal do Paraná (CHC-UFPR), Setor de Infectologia, Setor de Bacteriologia, Unidade de Laboratório de Análises Clínicas (ULAC) Curitiba, Paraná, Brasil
| | - Sonia Mara Raboni
- Complexo Hospital de Clínicas, Universidade Federal do Paraná (CHC-UFPR), Setor de Infectologia, Setor de Bacteriologia, Unidade de Laboratório de Análises Clínicas (ULAC) Curitiba, Paraná, Brasil
| | - Gislene Maria Botão Kussen
- Complexo Hospital de Clínicas, Universidade Federal do Paraná (CHC-UFPR), Setor de Infectologia, Setor de Bacteriologia, Unidade de Laboratório de Análises Clínicas (ULAC) Curitiba, Paraná, Brasil
| | - Keite da Silva Nogueira
- Programa de Pós graduação em Biotecnologia Aplicada à Saúde da Criança e do Adolescente da Faculdades Pequeno Príncipe (FPP), Instituto de Pesquisa Pelé Pequeno Príncipe (IPPPP), Curitiba, Paraná, Brasil
- Complexo Hospital de Clínicas, Universidade Federal do Paraná (CHC-UFPR), Setor de Infectologia, Setor de Bacteriologia, Unidade de Laboratório de Análises Clínicas (ULAC) Curitiba, Paraná, Brasil
| | - Clea Elisa Lopes Ribeiro
- Secretaria Municipal da Saúde, Setor Vigilância Epidemiológica de HIV/AIDS, Curitiba, Paraná, Brasil
| | - Libera Maria Dalla Costa
- Programa de Pós graduação em Biotecnologia Aplicada à Saúde da Criança e do Adolescente da Faculdades Pequeno Príncipe (FPP), Instituto de Pesquisa Pelé Pequeno Príncipe (IPPPP), Curitiba, Paraná, Brasil
- Complexo Hospital de Clínicas, Universidade Federal do Paraná (CHC-UFPR), Setor de Infectologia, Setor de Bacteriologia, Unidade de Laboratório de Análises Clínicas (ULAC) Curitiba, Paraná, Brasil
- * E-mail:
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Zifodya JS, Kreniske JS, Schiller I, Kohli M, Dendukuri N, Schumacher SG, Ochodo EA, Haraka F, Zwerling AA, Pai M, Steingart KR, Horne DJ. Xpert Ultra versus Xpert MTB/RIF for pulmonary tuberculosis and rifampicin resistance in adults with presumptive pulmonary tuberculosis. Cochrane Database Syst Rev 2021; 2:CD009593. [PMID: 33616229 DOI: 10.1002/14651858.cd009593.pub5] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Xpert MTB/RIF and Xpert MTB/RIF Ultra (Xpert Ultra) are World Health Organization (WHO)-recommended rapid tests that simultaneously detect tuberculosis and rifampicin resistance in people with signs and symptoms of tuberculosis. This review builds on our recent extensive Cochrane Review of Xpert MTB/RIF accuracy. OBJECTIVES To compare the diagnostic accuracy of Xpert Ultra and Xpert MTB/RIF for the detection of pulmonary tuberculosis and detection of rifampicin resistance in adults with presumptive pulmonary tuberculosis. For pulmonary tuberculosis and rifampicin resistance, we also investigated potential sources of heterogeneity. We also summarized the frequency of Xpert Ultra trace-positive results, and estimated the accuracy of Xpert Ultra after repeat testing in those with trace-positive results. SEARCH METHODS We searched the Cochrane Infectious Diseases Group Specialized Register, MEDLINE, Embase, Science Citation Index, Web of Science, LILACS, Scopus, the WHO ICTRP, the ISRCTN registry, and ProQuest to 28 January 2020 with no language restriction. SELECTION CRITERIA We included diagnostic accuracy studies using respiratory specimens in adults with presumptive pulmonary tuberculosis that directly compared the index tests. For pulmonary tuberculosis detection, the reference standards were culture and a composite reference standard. For rifampicin resistance, the reference standards were culture-based drug susceptibility testing and line probe assays. DATA COLLECTION AND ANALYSIS Two review authors independently extracted data using a standardized form, including data by smear and HIV status. We assessed risk of bias using QUADAS-2 and QUADAS-C. We performed meta-analyses comparing pooled sensitivities and specificities, separately for pulmonary tuberculosis detection and rifampicin resistance detection, and separately by reference standard. Most analyses used a bivariate random-effects model. For tuberculosis detection, we estimated accuracy in studies in participants who were not selected based on prior microscopy testing or history of tuberculosis. We performed subgroup analyses by smear status, HIV status, and history of tuberculosis. We summarized Xpert Ultra trace results. MAIN RESULTS We identified nine studies (3500 participants): seven had unselected participants (2834 participants). All compared Xpert Ultra and Xpert MTB/RIF for pulmonary tuberculosis detection; seven studies used a paired comparative accuracy design, and two studies used a randomized design. Five studies compared Xpert Ultra and Xpert MTB/RIF for rifampicin resistance detection; four studies used a paired design, and one study used a randomized design. Of the nine included studies, seven (78%) were mainly or exclusively in high tuberculosis burden countries. For pulmonary tuberculosis detection, most studies had low risk of bias in all domains. Pulmonary tuberculosis detection Xpert Ultra pooled sensitivity and specificity (95% credible interval) against culture were 90.9% (86.2 to 94.7) and 95.6% (93.0 to 97.4) (7 studies, 2834 participants; high-certainty evidence) versus Xpert MTB/RIF pooled sensitivity and specificity of 84.7% (78.6 to 89.9) and 98.4% (97.0 to 99.3) (7 studies, 2835 participants; high-certainty evidence). The difference in the accuracy of Xpert Ultra minus Xpert MTB/RIF was estimated at 6.3% (0.1 to 12.8) for sensitivity and -2.7% (-5.7 to -0.5) for specificity. If the point estimates for Xpert Ultra and Xpert MTB/RIF are applied to a hypothetical cohort of 1000 patients, where 10% of those presenting with symptoms have pulmonary tuberculosis, Xpert Ultra will miss 9 cases, and Xpert MTB/RIF will miss 15 cases. The number of people wrongly diagnosed with pulmonary tuberculosis would be 40 with Xpert Ultra and 14 with Xpert MTB/RIF. In smear-negative, culture-positive participants, pooled sensitivity was 77.5% (67.6 to 85.6) for Xpert Ultra versus 60.6% (48.4 to 71.7) for Xpert MTB/RIF; pooled specificity was 95.8% (92.9 to 97.7) for Xpert Ultra versus 98.8% (97.7 to 99.5) for Xpert MTB/RIF (6 studies). In people living with HIV, pooled sensitivity was 87.6% (75.4 to 94.1) for Xpert Ultra versus 74.9% (58.7 to 86.2) for Xpert MTB/RIF; pooled specificity was 92.8% (82.3 to 97.0) for Xpert Ultra versus 99.7% (98.6 to 100.0) for Xpert MTB/RIF (3 studies). In participants with a history of tuberculosis, pooled sensitivity was 84.2% (72.5 to 91.7) for Xpert Ultra versus 81.8% (68.7 to 90.0) for Xpert MTB/RIF; pooled specificity was 88.2% (70.5 to 96.6) for Xpert Ultra versus 97.4% (91.7 to 99.5) for Xpert MTB/RIF (4 studies). The proportion of Ultra trace-positive results ranged from 3.0% to 30.4%. Data were insufficient to estimate the accuracy of Xpert Ultra repeat testing in individuals with initial trace-positive results. Rifampicin resistance detection Pooled sensitivity and specificity were 94.9% (88.9 to 97.9) and 99.1% (97.7 to 99.8) (5 studies, 921 participants; high-certainty evidence) for Xpert Ultra versus 95.3% (90.0 to 98.1) and 98.8% (97.2 to 99.6) (5 studies, 930 participants; high-certainty evidence) for Xpert MTB/RIF. The difference in the accuracy of Xpert Ultra minus Xpert MTB/RIF was estimated at -0.3% (-6.9 to 5.7) for sensitivity and 0.3% (-1.2 to 2.0) for specificity. If the point estimates for Xpert Ultra and Xpert MTB/RIF are applied to a hypothetical cohort of 1000 patients, where 10% of those presenting with symptoms have rifampicin resistance, Xpert Ultra will miss 5 cases, and Xpert MTB/RIF will miss 5 cases. The number of people wrongly diagnosed with rifampicin resistance would be 8 with Xpert Ultra and 11 with Xpert MTB/RIF. We identified a higher number of rifampicin resistance indeterminate results with Xpert Ultra, pooled proportion 7.6% (2.4 to 21.0) compared to Xpert MTB/RIF pooled proportion 0.8% (0.2 to 2.4). The estimated difference in the pooled proportion of indeterminate rifampicin resistance results for Xpert Ultra versus Xpert MTB/RIF was 6.7% (1.4 to 20.1). AUTHORS' CONCLUSIONS Xpert Ultra has higher sensitivity and lower specificity than Xpert MTB/RIF for pulmonary tuberculosis, especially in smear-negative participants and people living with HIV. Xpert Ultra specificity was lower than that of Xpert MTB/RIF in participants with a history of tuberculosis. The sensitivity and specificity trade-off would be expected to vary by setting. For detection of rifampicin resistance, Xpert Ultra and Xpert MTB/RIF had similar sensitivity and specificity. Ultra trace-positive results were common. Xpert Ultra and Xpert MTB/RIF provide accurate results and can allow rapid initiation of treatment for rifampicin-resistant and multidrug-resistant tuberculosis.
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Affiliation(s)
- Jerry S Zifodya
- Department of Medicine, Section of Pulmonary, Critical Care, & Environmental Medicine , Tulane University, New Orleans, LA, USA
| | - Jonah S Kreniske
- Department of Internal Medicine, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | - Ian Schiller
- Centre for Outcomes Research, McGill University Health Centre - Research Institute, Montreal, Canada
| | - Mikashmi Kohli
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Canada
| | - Nandini Dendukuri
- Centre for Outcomes Research, McGill University Health Centre - Research Institute, Montreal, Canada
| | | | - Eleanor A Ochodo
- Centre for Evidence-based Health Care, Department of Global Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Frederick Haraka
- Elizabeth Glaser Pediatric AIDS Foundation, Dar es Salaam, Tanzania
- Ifakara Health Institute, Bagamoyo, Tanzania
| | - Alice A Zwerling
- School of Epidemiology & Public Health, University of Ottawa, Ottawa, Canada
| | - Madhukar Pai
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Canada
| | - Karen R Steingart
- Honorary Research Fellow, Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - David J Horne
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, and Firland Northwest TB Center, University of Washington, Seattle, WA, USA
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Ngabonziza JCS, Decroo T, Maniliho R, Habimana YM, Van Deun A, de Jong BC. Low Cycle Threshold Value in Xpert MTB/RIF Assay May Herald False Detection of Tuberculosis and Rifampicin Resistance: A Study of Two Cases. Open Forum Infect Dis 2021; 8:ofab034. [PMID: 33614819 PMCID: PMC7885858 DOI: 10.1093/ofid/ofab034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 01/19/2021] [Indexed: 11/15/2022] Open
Abstract
We report 2 cases for whom Xpert MTB/RIF falsely signaled rifampicin-resistant tuberculosis, based on unusually low cycle threshold and 3 of 5 probes missing. Other mycobacterial tests were negative. Further optimization of the Xpert MTB/RIF algorithm is warranted.
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Affiliation(s)
- Jean Claude S Ngabonziza
- National Reference Laboratory Division, Department of Biomedical Services, Rwanda Biomedical Centre, Kigali, Rwanda
- Mycobacteriology Unit, Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Tom Decroo
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Research Foundation Flanders, Brussels, Belgium
| | | | - Yves M Habimana
- Tuberculosis and Other Respiratory Diseases Division, Institute of HIV/AIDS Disease Prevention and Control, Rwanda Biomedical Center, Kigali, Rwanda
| | | | - Bouke C de Jong
- Mycobacteriology Unit, Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
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Omar A, Elfadl AEA, Ahmed Y, Hosny M. Valuing the use of GeneXpert test as an unconventional approach to diagnose pulmonary tuberculosis. THE EGYPTIAN JOURNAL OF BRONCHOLOGY 2019. [DOI: 10.4103/ejb.ejb_88_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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13
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Horne DJ, Kohli M, Zifodya JS, Schiller I, Dendukuri N, Tollefson D, Schumacher SG, Ochodo EA, Pai M, Steingart KR. Xpert MTB/RIF and Xpert MTB/RIF Ultra for pulmonary tuberculosis and rifampicin resistance in adults. Cochrane Database Syst Rev 2019; 6:CD009593. [PMID: 31173647 PMCID: PMC6555588 DOI: 10.1002/14651858.cd009593.pub4] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND Xpert MTB/RIF (Xpert MTB/RIF) and Xpert MTB/RIF Ultra (Xpert Ultra), the newest version, are the only World Health Organization (WHO)-recommended rapid tests that simultaneously detect tuberculosis and rifampicin resistance in persons with signs and symptoms of tuberculosis, at lower health system levels. A previous Cochrane Review found Xpert MTB/RIF sensitive and specific for tuberculosis (Steingart 2014). Since the previous review, new studies have been published. We performed a review update for an upcoming WHO policy review. OBJECTIVES To determine diagnostic accuracy of Xpert MTB/RIF and Xpert Ultra for tuberculosis in adults with presumptive pulmonary tuberculosis (PTB) and for rifampicin resistance in adults with presumptive rifampicin-resistant tuberculosis. SEARCH METHODS We searched the Cochrane Infectious Diseases Group Specialized Register, MEDLINE, Embase, Science Citation Index, Web of Science, Latin American Caribbean Health Sciences Literature, Scopus, the WHO International Clinical Trials Registry Platform, the International Standard Randomized Controlled Trial Number Registry, and ProQuest, to 11 October 2018, without language restriction. SELECTION CRITERIA Randomized trials, cross-sectional, and cohort studies using respiratory specimens that evaluated Xpert MTB/RIF, Xpert Ultra, or both against the reference standard, culture for tuberculosis and culture-based drug susceptibility testing or MTBDRplus for rifampicin resistance. DATA COLLECTION AND ANALYSIS Four review authors independently extracted data using a standardized form. When possible, we also extracted data by smear and HIV status. We assessed study quality using QUADAS-2 and performed meta-analyses to estimate pooled sensitivity and specificity separately for tuberculosis and rifampicin resistance. We investigated potential sources of heterogeneity. Most analyses used a bivariate random-effects model. For tuberculosis detection, we first estimated accuracy using all included studies and then only the subset of studies where participants were unselected, i.e. not selected based on prior microscopy testing. MAIN RESULTS We identified in total 95 studies (77 new studies since the previous review): 86 studies (42,091 participants) evaluated Xpert MTB/RIF for tuberculosis and 57 studies (8287 participants) for rifampicin resistance. One study compared Xpert MTB/RIF and Xpert Ultra on the same participant specimen.Tuberculosis detectionOf the total 86 studies, 45 took place in high tuberculosis burden and 50 in high TB/HIV burden countries. Most studies had low risk of bias.Xpert MTB/RIF pooled sensitivity and specificity (95% credible Interval (CrI)) were 85% (82% to 88%) and 98% (97% to 98%), (70 studies, 37,237 unselected participants; high-certainty evidence). We found similar accuracy when we included all studies.For a population of 1000 people where 100 have tuberculosis on culture, 103 would be Xpert MTB/RIF-positive and 18 (17%) would not have tuberculosis (false-positives); 897 would be Xpert MTB/RIF-negative and 15 (2%) would have tuberculosis (false-negatives).Xpert Ultra sensitivity (95% confidence interval (CI)) was 88% (85% to 91%) versus Xpert MTB/RIF 83% (79% to 86%); Xpert Ultra specificity was 96% (94% to 97%) versus Xpert MTB/RIF 98% (97% to 99%), (1 study, 1439 participants; moderate-certainty evidence).Xpert MTB/RIF pooled sensitivity was 98% (97% to 98%) in smear-positive and 67% (62% to 72%) in smear-negative, culture-positive participants, (45 studies). Xpert MTB/RIF pooled sensitivity was 88% (83% to 92%) in HIV-negative and 81% (75% to 86%) in HIV-positive participants; specificities were similar 98% (97% to 99%), (14 studies).Rifampicin resistance detectionXpert MTB/RIF pooled sensitivity and specificity (95% Crl) were 96% (94% to 97%) and 98% (98% to 99%), (48 studies, 8020 participants; high-certainty evidence).For a population of 1000 people where 100 have rifampicin-resistant tuberculosis, 114 would be positive for rifampicin-resistant tuberculosis and 18 (16%) would not have rifampicin resistance (false-positives); 886 would be would be negative for rifampicin-resistant tuberculosis and four (0.4%) would have rifampicin resistance (false-negatives).Xpert Ultra sensitivity (95% CI) was 95% (90% to 98%) versus Xpert MTB/RIF 95% (91% to 98%); Xpert Ultra specificity was 98% (97% to 99%) versus Xpert MTB/RIF 98% (96% to 99%), (1 study, 551 participants; moderate-certainty evidence). AUTHORS' CONCLUSIONS We found Xpert MTB/RIF to be sensitive and specific for diagnosing PTB and rifampicin resistance, consistent with findings reported previously. Xpert MTB/RIF was more sensitive for tuberculosis in smear-positive than smear-negative participants and HIV-negative than HIV-positive participants. Compared with Xpert MTB/RIF, Xpert Ultra had higher sensitivity and lower specificity for tuberculosis and similar sensitivity and specificity for rifampicin resistance (1 study). Xpert MTB/RIF and Xpert Ultra provide accurate results and can allow rapid initiation of treatment for multidrug-resistant tuberculosis.
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Affiliation(s)
- David J Horne
- University of WashingtonDepartment of Medicine, Division of Pulmonary and Critical Care Medicine, and Firland Northwest TB CenterSeattleUSA
| | - Mikashmi Kohli
- McGill UniversityDepartment of Epidemiology, Biostatistics and Occupational HealthMontrealCanada
| | - Jerry S Zifodya
- University of WashingtonPulmonary and Critical Care Medicine325 9th Avenue – Campus Box 359762SeattleUSA98104
| | - Ian Schiller
- McGill University Health Centre ‐ Research InstituteDivision of Clinical EpidemiologyMontrealCanada
| | - Nandini Dendukuri
- McGill University Health Centre ‐ Research InstituteDivision of Clinical EpidemiologyMontrealCanada
| | | | | | - Eleanor A Ochodo
- Stellenbosch UniversityCentre for Evidence‐based Health Care, Faculty of Medicine and Health SciencesPO Box 241Cape TownSouth Africa8000
| | - Madhukar Pai
- McGill UniversityDepartment of Epidemiology, Biostatistics and Occupational HealthMontrealCanada
| | - Karen R Steingart
- Department of Clinical Sciences, Liverpool School of Tropical MedicineHonorary Research FellowPembroke PlaceLiverpoolUK
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Hu P, Zhang H, Fleming J, Zhu G, Zhang S, Wang Y, Liu F, Yi S, Chen Z, Chen Z, Liu B, Gong D, Wan L, Wang X, Tan Y, Bai L, Bi L. Retrospective Analysis of False-Positive and Disputed Rifampin Resistance Xpert MTB/RIF Assay Results in Clinical Samples from a Referral Hospital in Hunan, China. J Clin Microbiol 2019; 57:e01707-18. [PMID: 30674578 PMCID: PMC6440781 DOI: 10.1128/jcm.01707-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 01/16/2019] [Indexed: 11/20/2022] Open
Abstract
Concerns about the specificity of the Xpert MTB/RIF (Xpert) assay have arisen, as false-positive errors in the determination of Mycobacterium tuberculosis complex (MTBC) infection and rifampin (RIF) resistance in clinical practice have been reported. Here, we investigated 33 cases where patients were determined to be RIF susceptible using the Bactec MGIT 960 (MGIT) culture system but RIF resistant using the Xpert assay. Isolates from two of these patients were found not to have any mutations in the rifampin resistance determining region (RRDR) region of rpoB and had good treatment outcomes with first-line antituberculosis (anti-TB) drugs. The remaining 31 patients included 5 new cases and 26 previously treated patients. A large number of well-documented disputed mutations, including Leu511Pro, Asp516Tyr, His526Asn, His526Leu, His526Cys, and Leu533Pro, were detected, and mutations, including a 508 to 509 deletion and His526Gly, were described here as disputed mutations for the first time. Twenty-one (81%) of the 26 previously treated patients had poor treatment outcomes, and isolates from 19 (90%) of these 21 patients were resistant to isoniazid (INH) as determined using the MGIT culture system. Twenty-seven of the 31 isolates with disputed rpoB mutations were phenotypically resistant to INH, 21 (78%) being predicted by GenoType MTBDRplus to have a high level of INH resistance. Most (77.4%) of the isolates with disputed mutations were of the Beijing lineage. These findings have implications for the interpretation of false-positive and disputed rifampin resistance Xpert MTB/RIF results in clinical samples and provide guidance on how clinicians should manage patients carrying isolates with disputed rpoB mutations.
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Affiliation(s)
- Peilei Hu
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
- Clinical Laboratory, Hunan Chest Hospital, Changsha, China
| | - Hongtai Zhang
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Joy Fleming
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Guofeng Zhu
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Shuai Zhang
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Yaguo Wang
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Fengping Liu
- Clinical Laboratory, Hunan Chest Hospital, Changsha, China
| | - Songlin Yi
- Clinical Laboratory, Hunan Chest Hospital, Changsha, China
| | - Zhongnan Chen
- Clinical Laboratory, Hunan Chest Hospital, Changsha, China
| | - Zhenhua Chen
- Clinical Laboratory, Hunan Chest Hospital, Changsha, China
| | - Binbin Liu
- Clinical Laboratory, Hunan Chest Hospital, Changsha, China
| | - Daofang Gong
- Clinical Laboratory, Hunan Chest Hospital, Changsha, China
| | - Li Wan
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Xingyun Wang
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Yunhong Tan
- Clinical Laboratory, Hunan Chest Hospital, Changsha, China
| | - Liqiong Bai
- Clinical Laboratory, Hunan Chest Hospital, Changsha, China
| | - Lijun Bi
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- School of Stomatology and Medicine, Foshan University, Foshan, Guangdong, China
- Guangdong Province Key Laboratory of TB Systems Biology and Translational Medicine, Foshan, Guangdong, China
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15
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Piersimoni C, Gherardi G, Gracciotti N, Pocognoli A. Comparative evaluation of Xpert MTB/RIF and the new Xpert MTB/RIF ultra with respiratory and extra-pulmonary specimens for tuberculosis case detection in a low incidence setting. J Clin Tuberc Other Mycobact Dis 2019; 15:100094. [PMID: 31720421 PMCID: PMC6830143 DOI: 10.1016/j.jctube.2019.100094] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Background The Xpert MTB/RIF assay (Xpert) is an automated molecular test for the detection of tuberculosis and rifampin resistance (RIF-R), but it lacks sensitivity in smear-negative samples and some limitations in determination of RIF-R have also been reported. The new Xpert MTB/RIF Ultra (Ultra) was developed to overcome these limitations. We aimed to compare Ultra and Xpert diagnostic accuracy setting culture and drug susceptibility testing as reference standards. Methods A retrospective analysis was performed on 359 consecutive, respiratory (269) and extrapulmonary (90) specimens collected from 340 patients investigated for TB along a two-year period. Patients presenting at primary health-care centres and hospitals were recruited on the basis of symptoms and abnormal X-ray imaging. One-hundred seventy-four subjects were identified to have active tuberculosis by culture and 2 were MDR. Findings Sensitivities of Ultra and Xpert were 87% and 75% for the 48 individuals with smear-negative and culture-positive respiratory TB (difference of 12%, 95% CI 3 to 21); 95% and 72% for the 40 individuals with smear-negative and culture-positive extrapulmonary disease (22%, 95% CI 10 to 34); and 95% and 86%, respectively, across all 174 individuals with culture-positive samples (8.5%, 95% CI 4.5 to 12.5). Specificities of Ultra and Xpert for tuberculosis case detection were 98% and 100% (-2.0%, 95% CI -4.3 to +0.3). Ultra and Xpert performed equal in detecting RIF-R. Interpretation Sensitivity of Ultra was superior to that of Xpert in all categories of clinical samples. However, improved sensitivity was associated with a modest reduction in specificity.
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Affiliation(s)
- Claudio Piersimoni
- Regional Reference Mycobacteriology Laboratory, Clinical Pathology Laboratory, United Hospitals, Ancona, Italy
| | - Giancarlo Gherardi
- Regional Reference Mycobacteriology Laboratory, Clinical Pathology Laboratory, United Hospitals, Ancona, Italy
| | - Natascia Gracciotti
- Regional Reference Mycobacteriology Laboratory, Clinical Pathology Laboratory, United Hospitals, Ancona, Italy
| | - Antonella Pocognoli
- Regional Reference Mycobacteriology Laboratory, Clinical Pathology Laboratory, United Hospitals, Ancona, Italy
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Silva TMD, Soares VM, Ramos MG, Santos AD. Accuracy of a rapid molecular test for tuberculosis in sputum samples, bronchoalveolar lavage fluid, and tracheal aspirate obtained from patients with suspected pulmonary tuberculosis at a tertiary referral hospital. ACTA ACUST UNITED AC 2019; 45:e20170451. [PMID: 30864607 PMCID: PMC6733743 DOI: 10.1590/1806-3713/e20170451] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 08/12/2018] [Indexed: 12/03/2022]
Abstract
Tuberculosis continues to be a major public health problem worldwide. The aim of the present study was to evaluate the accuracy of the Xpert MTB/RIF rapid molecular test for tuberculosis, using pulmonary samples obtained from patients treated at the Júlia Kubitschek Hospital, which is operated by the Hospital Foundation of the State of Minas Gerais, in the city of Belo Horizonte, Brazil. This was a retrospective study comparing the Xpert MTB/RIF test results with those of standard culture for Mycobacterium tuberculosis and phenotypic susceptibility tests. Although the Xpert MTB/RIF test showed high accuracy for the detection of M. tuberculosis and its resistance to rifampin, attention must be given to the clinical status of the patient, in relation to the test results, as well as to the limitations of molecular tests.
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Affiliation(s)
- Tatiane Maria da Silva
- . Faculdade de Biomedicina, Universidade da Fundação Mineira de Educação e Cultura - FUMEC - Belo Horizonte (MG) Brasil
| | - Valéria Martins Soares
- . Setor de Microbiologia, Laboratório do Hospital Júlia Kubitschek, Fundação Hospitalar do Estado de Minas Gerais - FHEMIG - Belo Horizonte (MG) Brasil
| | - Mariana Gontijo Ramos
- . Faculdade de Biomedicina, Universidade da Fundação Mineira de Educação e Cultura - FUMEC - Belo Horizonte (MG) Brasil
| | - Adriana Dos Santos
- . Faculdade de Biomedicina, Universidade da Fundação Mineira de Educação e Cultura - FUMEC - Belo Horizonte (MG) Brasil
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Ahmed S. GeneXpert MTB/RIF assay – A major milestone for diagnosing Mycobacterium tuberculosis and rifampicin-resistant cases in pulmonary and extrapulmonary specimens. MEDICAL JOURNAL OF BABYLON 2019. [DOI: 10.4103/mjbl.mjbl_62_19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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18
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Hasnain SE, Ehtesham NZ, Grover S. Clinical Aspects and Principles of Management of Tuberculosis. MYCOBACTERIUM TUBERCULOSIS: MOLECULAR INFECTION BIOLOGY, PATHOGENESIS, DIAGNOSTICS AND NEW INTERVENTIONS 2019. [PMCID: PMC7120521 DOI: 10.1007/978-981-32-9413-4_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Tuberculosis over the ages, has killed more people than any other infection has. Notwithstanding the advances in modern science, clinical diagnosis sometimes remains elusive, owing principally to the frequent paucibacillary occurrence of the disease and the slow doubling time of the organism; empiric treatment is often fraught with risks in the era of increasing drug resistance. This chapter attempts to provide an overview of the disease, beginning with the pathogenesis and its protean clinical presentations. It also discusses the recent evolution of molecular methods that have lately provided an impetus to early diagnosis with a clear opportunity to unmask drug resistance before initiating “blind”, potentially ineffective, and sometimes harmful treatment with standard therapy. The chapter also provides insight into tuberculosis in special situations, and discusses briefly the treatments in uncomplicated cases as well as in special situations, and in instances of drug resistance. Preventive methods including current and upcoming vaccines are mentioned. Finally, a short discussion of the sequelae of tuberculosis—which have the potential to be confused with active disease—is presented.
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Affiliation(s)
| | - Nasreen Z. Ehtesham
- Inflammation Biology and Cell Signaling Laboratory, ICMR-National Institute of Pathology, Safdarjung Hospital Campus, New Delhi, Delhi India
| | - Sonam Grover
- JH Institute of Molecular Medicine, Jamia Hamdard, New Delhi, Delhi India
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Tratamiento de la enfermedad tuberculosa pulmonar y extrapulmonar. Enferm Infecc Microbiol Clin 2018; 36:507-516. [DOI: 10.1016/j.eimc.2017.10.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 10/12/2017] [Indexed: 11/19/2022]
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21
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Kohli M, Schiller I, Dendukuri N, Dheda K, Denkinger CM, Schumacher SG, Steingart KR. Xpert ® MTB/RIF assay for extrapulmonary tuberculosis and rifampicin resistance. Cochrane Database Syst Rev 2018; 8:CD012768. [PMID: 30148542 PMCID: PMC6513199 DOI: 10.1002/14651858.cd012768.pub2] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Tuberculosis (TB) is the world's leading infectious cause of death. Extrapulmonary TB accounts for 15% of TB cases, but the proportion is increasing, and over half a million people were newly diagnosed with rifampicin-resistant TB in 2016. Xpert® MTB/RIF (Xpert) is a World Health Organization (WHO)-recommended, rapid, automated, nucleic acid amplification assay that is used widely for simultaneous detection of Mycobacterium tuberculosis complex and rifampicin resistance in sputum specimens. This Cochrane Review assessed the accuracy of Xpert in extrapulmonary specimens. OBJECTIVES To determine the diagnostic accuracy of Xpert a) for extrapulmonary TB by site of disease in people presumed to have extrapulmonary TB; and b) for rifampicin resistance in people presumed to have extrapulmonary TB. SEARCH METHODS We searched the Cochrane Infectious Diseases Group Specialized Register, MEDLINE, Embase, Science Citation Index, Web of Science, Latin American Caribbean Health Sciences Literature (LILACS), Scopus, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform, the International Standard Randomized Controlled Trial Number (ISRCTN) Registry, and ProQuest up to 7 August 2017 without language restriction. SELECTION CRITERIA We included diagnostic accuracy studies of Xpert in people presumed to have extrapulmonary TB. We included TB meningitis and pleural, lymph node, bone or joint, genitourinary, peritoneal, pericardial, and disseminated TB. We used culture as the reference standard. For pleural TB, we also included a composite reference standard, which defined a positive result as the presence of granulomatous inflammation or a positive culture result. For rifampicin resistance, we used culture-based drug susceptibility testing or MTBDRplus as the reference standard. DATA COLLECTION AND ANALYSIS Two review authors independently extracted data, assessed risk of bias and applicability using the QUADAS-2 tool. We determined pooled predicted sensitivity and specificity for TB, grouped by type of extrapulmonary specimen, and for rifampicin resistance. For TB detection, we used a bivariate random-effects model. Recognizing that use of culture may lead to misclassification of cases of extrapulmonary TB as 'not TB' owing to the paucibacillary nature of the disease, we adjusted accuracy estimates by applying a latent class meta-analysis model. For rifampicin resistance detection, we performed univariate meta-analyses for sensitivity and specificity separately to include studies in which no rifampicin resistance was detected. We used theoretical populations with an assumed prevalence to provide illustrative numbers of patients with false positive and false negative results. MAIN RESULTS We included 66 unique studies that evaluated 16,213 specimens for detection of extrapulmonary TB and rifampicin resistance. We identified only one study that evaluated the newest test version, Xpert MTB/RIF Ultra (Ultra), for TB meningitis. Fifty studies (76%) took place in low- or middle-income countries. Risk of bias was low for patient selection, index test, and flow and timing domains and was high or unclear for the reference standard domain (most of these studies decontaminated sterile specimens before culture inoculation). Regarding applicability, in the patient selection domain, we scored high or unclear concern for most studies because either patients were evaluated exclusively as inpatients at tertiary care centres, or we were not sure about the clinical settings.Pooled Xpert sensitivity (defined by culture) varied across different types of specimens (31% in pleural tissue to 97% in bone or joint fluid); Xpert sensitivity was > 80% in urine and bone or joint fluid and tissue. Pooled Xpert specificity (defined by culture) varied less than sensitivity (82% in bone or joint tissue to 99% in pleural fluid and urine). Xpert specificity was ≥ 98% in cerebrospinal fluid, pleural fluid, urine, and peritoneal fluid.Xpert testing in cerebrospinal fluidXpert pooled sensitivity and specificity (95% credible interval (CrI)) against culture were 71.1% (60.9% to 80.4%) and 98.0% (97.0% to 98.8%), respectively (29 studies, 3774 specimens; moderate-certainty evidence).For a population of 1000 people where 100 have TB meningitis on culture, 89 would be Xpert-positive: of these, 18 (20%) would not have TB (false-positives); and 911 would be Xpert-negative: of these, 29 (3%) would have TB (false-negatives).For TB meningitis, ultra sensitivity and specificity against culture (95% confidence interval (CI)) were 90% (55% to 100%) and 90% (83% to 95%), respectively (one study, 129 participants).Xpert testing in pleural fluidXpert pooled sensitivity and specificity (95% CrI) against culture were 50.9% (39.7% to 62.8%) and 99.2% (98.2% to 99.7%), respectively (27 studies, 4006 specimens; low-certainty evidence).For a population of 1000 people where 150 have pleural TB on culture, 83 would be Xpert-positive: of these, seven (8%) would not have TB (false-positives); and 917 would be Xpert-negative: of these, 74 (8%) would have TB (false-negatives).Xpert testing in urineXpert pooled sensitivity and specificity (95% CrI) against culture were 82.7% (69.6% to 91.1%) and 98.7% (94.8% to 99.7%), respectively (13 studies, 1199 specimens; moderate-certainty evidence).For a population of 1000 people where 70 have genitourinary TB on culture, 70 would be Xpert-positive: of these, 12 (17%) would not have TB (false-positives); and 930 would be Xpert-negative: of these, 12 (1%) would have TB (false-negatives).Xpert testing for rifampicin resistanceXpert pooled sensitivity (20 studies, 148 specimens) and specificity (39 studies, 1088 specimens) were 95.0% (89.7% to 97.9%) and 98.7% (97.8% to 99.4%), respectively (high-certainty evidence).For a population of 1000 people where 120 have rifampicin-resistant TB, 125 would be positive for rifampicin-resistant TB: of these, 11 (9%) would not have rifampicin resistance (false-positives); and 875 would be negative for rifampicin-resistant TB: of these, 6 (1%) would have rifampicin resistance (false-negatives).For lymph node TB, the accuracy of culture, the reference standard used, presented a greater concern for bias than in other forms of extrapulmonary TB. AUTHORS' CONCLUSIONS In people presumed to have extrapulmonary TB, Xpert may be helpful in confirming the diagnosis. Xpert sensitivity varies across different extrapulmonary specimens, while for most specimens, specificity is high, the test rarely yielding a positive result for people without TB (defined by culture). Xpert is accurate for detection of rifampicin resistance. For people with presumed TB meningitis, treatment should be based on clinical judgement, and not withheld solely on an Xpert result, as is common practice when culture results are negative.
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Affiliation(s)
- Mikashmi Kohli
- McGill UniversityDepartment of Epidemiology, Biostatistics and Occupational HealthMontrealCanada
| | - Ian Schiller
- McGill University Health Centre ‐ Research InstituteDivision of Clinical EpidemiologyMontrealCanada
| | - Nandini Dendukuri
- McGill University Health Centre ‐ Research InstituteDivision of Clinical EpidemiologyMontrealCanada
| | - Keertan Dheda
- University of Cape Town3 Centre for Lung Infection and Immunity Unit, Department of Medicine and UCT Lung InstituteCape TownSouth Africa
| | | | | | - Karen R Steingart
- Department of Clinical Sciences, Liverpool School of Tropical MedicineHonorary Research FellowPembroke PlaceLiverpoolUK
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Patterson B, Morrow C, Singh V, Moosa A, Gqada M, Woodward J, Mizrahi V, Bryden W, Call C, Patel S, Warner D, Wood R. Detection of Mycobacterium tuberculosis bacilli in bio-aerosols from untreated TB patients. Gates Open Res 2018; 1:11. [PMID: 29355225 PMCID: PMC5757796 DOI: 10.12688/gatesopenres.12758.2] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2018] [Indexed: 12/02/2022] Open
Abstract
Background: Tuberculosis (TB) is predominantly an airborne disease. However, quantitative and qualitative analysis of bio-aerosols containing the aetiological agent,
Mycobacterium tuberculosis (Mtb), has proven very challenging. Our objective is to sample bio-aerosols from newly diagnosed TB patients for detection and enumeration of
Mtb bacilli. Methods: We monitored each of 35 newly diagnosed, GeneXpert sputum-positive, TB patients during 1 hour confinement in a custom-built Respiratory Aerosol Sampling Chamber (RASC). The RASC (a small clean-room of 1.4m
) incorporates aerodynamic particle size detection, viable and non-viable sampling devices, real-time CO
2 monitoring, and cough sound-recording. Microbiological culture and droplet digital polymerase chain reaction (ddPCR) were used to detect
Mtb in each of the bio-aerosol collection devices. Results:
Mtb was detected in 27/35 (77.1%) of aerosol samples; 15/35 (42.8%) samples were positive by mycobacterial culture and 25/27 (92.96%) were positive by ddPCR. Culturability of collected bacilli was not predicted by radiographic evidence of pulmonary cavitation, sputum smear positivity. A correlation was found between cough rate and culturable bioaerosol.
Mtb was detected on all viable cascade impactor stages with a peak at aerosol sizes 2.0-3.5μm. This suggests a median of 0.09 CFU/litre of exhaled air (IQR: 0.07 to 0.3 CFU/l) for the aerosol culture positives and an estimated median concentration of 4.5x10
CFU/ml (IQR: 2.9x10
-5.6x10
) of exhaled particulate bio-aerosol. Conclusions:
Mtb was identified in bio-aerosols exhaled by the majority of untreated TB patients using the RASC. Molecular detection was more sensitive than mycobacterial culture on solid media, suggesting that further studies are required to determine whether this reflects a significant proportion of differentially detectable bacilli in these samples.
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Affiliation(s)
- Benjamin Patterson
- Division of Infectious Diseases, Department of Medicine, Columbia University, College of Physicians and Surgeons, New York, NY, USA
| | - Carl Morrow
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,Desmond Tutu HIV Centre,Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
| | - Vinayak Singh
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Atica Moosa
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Melitta Gqada
- Desmond Tutu HIV Centre,Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
| | - Jeremy Woodward
- Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Valerie Mizrahi
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | | | | | - Shwetak Patel
- Computer Science and Engineering, Electrical Engineering DUB group, University of Washington, Seattle, USA
| | - Digby Warner
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Robin Wood
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,Desmond Tutu HIV Centre,Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
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23
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Patterson B, Morrow C, Singh V, Moosa A, Gqada M, Woodward J, Mizrahi V, Bryden W, Call C, Patel S, Warner D, Wood R. Detection of Mycobacterium tuberculosis bacilli in bio-aerosols from untreated TB patients. Gates Open Res 2018; 1:11. [PMID: 29355225 DOI: 10.12688/gatesopenres.12758.1] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2017] [Indexed: 11/20/2022] Open
Abstract
Background: Tuberculosis (TB) is predominantly an airborne disease. However, quantitative and qualitative analysis of bio-aerosols containing the aetiological agent, Mycobacterium tuberculosis (Mtb), has proven very challenging. Our objective is to sample bio-aerosols from newly diagnosed TB patients for detection and enumeration of Mtb bacilli. Methods: We monitored each of 35 newly diagnosed, GeneXpert sputum-positive, TB patients during 1 hour confinement in a custom-built Respiratory Aerosol Sampling Chamber (RASC). The RASC (a small clean-room of 1.4m ) incorporates aerodynamic particle size detection, viable and non-viable sampling devices, real-time CO 2 monitoring, and cough sound-recording. Microbiological culture and droplet digital polymerase chain reaction (ddPCR) were used to detect Mtb in each of the bio-aerosol collection devices. Results: Mtb was detected in 27/35 (77.1%) of aerosol samples; 15/35 (42.8%) samples were positive by mycobacterial culture and 25/27 (92.96%) were positive by ddPCR. Culturability of collected bacilli was not predicted by radiographic evidence of pulmonary cavitation, sputum smear positivity. A correlation was found between cough rate and culturable bioaerosol. Mtb was detected on all viable cascade impactor stages with a peak at aerosol sizes 2.0-3.5μm. This suggests a median of 0.09 CFU/litre of exhaled air (IQR: 0.07 to 0.3 CFU/l) for the aerosol culture positives and an estimated median concentration of 4.5x10 CFU/ml (IQR: 2.9x10 -5.6x10 ) of exhaled particulate bio-aerosol. Conclusions: Mtb was identified in bio-aerosols exhaled by the majority of untreated TB patients using the RASC. Molecular detection was more sensitive than mycobacterial culture on solid media, suggesting that further studies are required to determine whether this reflects a significant proportion of differentially detectable bacilli in these samples.
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Affiliation(s)
- Benjamin Patterson
- Division of Infectious Diseases, Department of Medicine, Columbia University, College of Physicians and Surgeons, New York, NY, USA
| | - Carl Morrow
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,Desmond Tutu HIV Centre,Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
| | - Vinayak Singh
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Atica Moosa
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Melitta Gqada
- Desmond Tutu HIV Centre,Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
| | - Jeremy Woodward
- Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Valerie Mizrahi
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | | | | | - Shwetak Patel
- Computer Science and Engineering, Electrical Engineering DUB group, University of Washington, Seattle, USA
| | - Digby Warner
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,MRC/NHLS/UCT Molecular Mycobacteriology Research Unit & DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Robin Wood
- Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,Desmond Tutu HIV Centre,Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
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Mohr E, Daniels J, Muller O, Furin J, Chabalala B, Steele SJ, Cox V, Dolby T, Ferlazzo G, Shroufi A, Duran LT, Cox H. Missed opportunities for earlier diagnosis of rifampicin-resistant tuberculosis despite access to Xpert ® MTB/RIF. Int J Tuberc Lung Dis 2018; 21:1100-1105. [PMID: 28911352 DOI: 10.5588/ijtld.17.0372] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE To assess the proportion of rifampicin-resistant tuberculosis (RR-TB) patients with potential earlier RR-TB diagnoses in Khayelitsha, South Africa. DESIGN We conducted a retrospective analysis among RR-TB patients diagnosed from 2012 to 2014. Patients were considered to have missed opportunities for earlier diagnosis if 1) they were incorrectly screened according to the Western Cape diagnostic algorithm; 2) the first specimen was not tested using Xpert® MTB/RIF; 3) no specimen was ever tested; or 4) the initial Xpert test showed a negative result, but no subsequent specimen was sent for follow-up testing in human immunodeficiency virus-positive patients. RESULTS Among 543 patients, 386 (71%) were diagnosed with Xpert and 112 (21%) had had at least one presentation at a health care facility within the 6 months before the presentation at which RR-TB was diagnosed. Overall, 95/543 (18%) patients were screened incorrectly at some point: 48 at diagnostic presentation only, 38 at previous presentation only, and 9 at both previous and diagnostic presentations. CONCLUSIONS These data show that a significant proportion of RR-TB patients might have been diagnosed earlier, and suggest that case detection could be improved if diagnostic algorithms were followed more closely. Further training and monitoring is required to ensure the greatest benefit from universal Xpert implementation.
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Affiliation(s)
- E Mohr
- Médecins Sans Frontières (MSF), Khayelitsha, South Africa
| | - J Daniels
- Médecins Sans Frontières (MSF), Khayelitsha, South Africa
| | - O Muller
- Médecins Sans Frontières (MSF), Khayelitsha, South Africa
| | - J Furin
- Harvard Medical School, Boston, Massachusetts, USA
| | - B Chabalala
- Médecins Sans Frontières (MSF), Khayelitsha, South Africa
| | | | - V Cox
- MSF, Eshowe, University of Cape Town Center for Infectious Disease Epidemiology and Research, Cape Town
| | - T Dolby
- National Health Laboratory Service, Cape Town
| | | | | | - L T Duran
- Médecins Sans Frontières (MSF), Khayelitsha, South Africa
| | - H Cox
- Division of Medical Microbiology and the Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
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25
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Click ES, Murithi W, Ouma GS, McCarthy K, Willby M, Musau S, Alexander H, Pevzner E, Posey J, Cain KP. Detection of Apparent Cell-free M. tuberculosis DNA from Plasma. Sci Rep 2018; 8:645. [PMID: 29330384 PMCID: PMC5766485 DOI: 10.1038/s41598-017-17683-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 11/29/2017] [Indexed: 11/26/2022] Open
Abstract
New diagnostics are needed to improve clinicians’ ability to detect tuberculosis (TB) disease in key populations such as children and persons living with HIV and to rapidly detect drug resistance. Circulating cell-free DNA (ccfDNA) in plasma is a diagnostic target in new obstetric and oncologic applications, but its utility for diagnosing TB is not known. Here we show that Mycobacterium tuberculosis complex DNA can be detected in plasma of persons with sputum smear-positive TB, even in the absence of mycobacteremia. Among 40 participants with bacteriologically-confirmed smear-positive TB disease who had plasma tested by quantitative PCR (qPCR), 18/40 (45%) had a positive result on at least one triplicate reaction. Our results suggest that plasma DNA may be a useful target for improving clinicians’ ability to diagnose TB. We anticipate these findings to be the starting point for optimized methods of TB ccfDNA testing and sequence-based diagnostic applications such as molecular detection of drug resistance.
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Affiliation(s)
- E S Click
- Centers for Disease Control and Prevention, Atlanta, GA, USA.
| | - W Murithi
- Kenya Medical Research Institute, Kisumu, Kenya
| | - G S Ouma
- Kenya Medical Research Institute, Kisumu, Kenya
| | - K McCarthy
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - M Willby
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - S Musau
- Kenya Medical Research Institute, Kisumu, Kenya
| | - H Alexander
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - E Pevzner
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - J Posey
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - K P Cain
- Centers for Disease Control and Prevention, Kisumu, Kenya
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Gowda NC, Ray A, Soneja M, Khanna A, Sinha S. Evaluation of Xpert ®Mycobacterium tuberculosis/rifampin in sputum-smear negative and sputum-scarce patients with pulmonary tuberculosis using bronchoalveolar lavage fluid. Lung India 2018; 35:295-300. [PMID: 29970767 PMCID: PMC6034363 DOI: 10.4103/lungindia.lungindia_412_17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Context: Sputum smear-negative and sputum-scarce pulmonary tuberculosis (PTB) is a diagnostic challenge. Xpert®Mycobacterium tuberculosis/rifampin (MTB/RIF) provides a rapid diagnosis on high-quality biological specimen obtained by bronchoscopy. Aims: The aim of this study is to evaluate Xpert® MTB/RIF on bronchoalveolar lavage (BAL) fluid in sputum smear-negative and sputum-scarce PTB patients. Settings: Tertiary care hospital in India. Design: This was prospective observational study. Materials and Methods: Between January 2015 and November 2016, we prospectively recruited sputum-smear negative and sputum-scarce patients under evaluation for PTB and performed BAL. Sensitivity, specificity, positive, and negative predictive values were calculated for the diagnosis of PTB on BAL fluid for acid-fast bacilli smear and Xpert® MTB/RIF using liquid culture as the reference standard and compared to the final diagnosis based on composite reference standard. Sensitivity, specificity, and predictive values were calculated with 95% class intervals. McNemar's test was used for comparison of sensitivities. Results: Of the 60 patients included, 52 (88.3%) had a final diagnosis of PTB and 16 (26.7%) were culture confirmed. Xpert® MTB/RIF had a sensitivity and specificity of 81% (54%–96%) and 73% (56%–85%) in culture confirmed cases; 46% (32%–60%) and 100% (63%–100%) for the final diagnosis; 32% (17%–51%) and 100% (54%–100%) in culture negative cases, respectively. Culture had a sensitivity of 32% (20%–47%) for the final diagnosis. Conclusions: In sputum smear-negative and sputum-scarce patients with clinico-radiological features of PTB Xpert® MTB/RIF has good sensitivity for diagnosis on BAL fluid. It is useful even when cultures are negative.
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Affiliation(s)
- Nikhil C Gowda
- Department of Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Animesh Ray
- Department of Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Manish Soneja
- Department of Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Arjun Khanna
- Department of Pulmonary Medicine and Critical Care Medicine, Yashoda Superspeciality Hospital, Kaushambi, Uttar Pradesh, India
| | - Sanjeev Sinha
- Department of Medicine, All India Institute of Medical Sciences, New Delhi, India
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Huang H, Zhang Y, Li S, Wang J, Chen J, Pan Z, Gan H. Rifampicin Resistance and Multidrug-Resistant Tuberculosis Detection Using Xpert MTB/RIF in Wuhan, China: A Retrospective Study. Microb Drug Resist 2017; 24:675-679. [PMID: 29053085 DOI: 10.1089/mdr.2017.0114] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The Xpert MTB/RIF test (Cepheid, Sunnyvale, CA) can simultaneously detect the Mycobacterium tuberculosis (MTB) complex DNA and rifampicin (RFP) resistance and can rapidly determine RFP resistance and predict multidrug-resistant tuberculosis (MDR-TB). In this study, we analyzed clinical examination results of a hospital specializing in TB treatment in Wuhan, Hubei, China, and examined the use of traditional culture and drug-sensitive test (DST) results as a gold standard to assess the diagnosis value of the Xpert MTB/RIF test in RFP resistance and MDR-TB. MATERIALS AND METHODS A total of 2,910 specimens were received in the Mycobacteriology Laboratory, Wuhan Pulmonary Hospital, for Xpert MTB/RIF testing between December 2013 and December 2014. After the results were reviewed by exclusion criteria, 1,066 Xpert test results were eligible for our study. We then compared the Xpert test results with sputum acid-fast bacilli staining, cultures, and DST results. RESULTS In total, Xpert correctly identified 96.71% (147/152) RFP-resistant TB and 98.25% (898/914) RFP-sensitive TB specimens. Of the 147 RFP-resistant TB specimens detected by Xpert, 122 MDR-TB (82.99%) were identified by traditional culture and DST techniques. CONCLUSIONS Xpert can simultaneously detect MTB and RFP resistance with high sensitivity and specificity. Thus, Xpert testing aids in saving a considerable amount of time in the diagnosis and treatment of MDR-TB.
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Affiliation(s)
- Hai Huang
- 1 Department of Tuberculosis Specialty, Wuhan Pulmonary Hospital , Wuhan, China
| | - Yanlin Zhang
- 1 Department of Tuberculosis Specialty, Wuhan Pulmonary Hospital , Wuhan, China
| | - Sheng Li
- 1 Department of Tuberculosis Specialty, Wuhan Pulmonary Hospital , Wuhan, China
| | - Jun Wang
- 1 Department of Tuberculosis Specialty, Wuhan Pulmonary Hospital , Wuhan, China
| | - Jun Chen
- 2 Department of Mycobacteriology Laboratory, Wuhan Pulmonary Hospital , Wuhan, China
| | - Zhiyun Pan
- 1 Department of Tuberculosis Specialty, Wuhan Pulmonary Hospital , Wuhan, China
| | - Hui Gan
- 1 Department of Tuberculosis Specialty, Wuhan Pulmonary Hospital , Wuhan, China .,3 Department of Allergy, Zhongnan Hospital of Wuhan University, Wuhan University , Wuhan, China
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The New Xpert MTB/RIF Ultra: Improving Detection of Mycobacterium tuberculosis and Resistance to Rifampin in an Assay Suitable for Point-of-Care Testing. mBio 2017; 8:mBio.00812-17. [PMID: 28851844 PMCID: PMC5574709 DOI: 10.1128/mbio.00812-17] [Citation(s) in RCA: 368] [Impact Index Per Article: 52.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The Xpert MTB/RIF assay (Xpert) is a rapid test for tuberculosis (TB) and rifampin resistance (RIF-R) suitable for point-of-care testing. However, it has decreased sensitivity in smear-negative sputum, and false identification of RIF-R occasionally occurs. We developed the Xpert MTB/RIF Ultra assay (Ultra) to improve performance. Ultra and Xpert limits of detection (LOD), dynamic ranges, and RIF-R rpoB mutation detection were tested on Mycobacterium tuberculosis DNA or sputum samples spiked with known numbers of M. tuberculosis H37Rv or Mycobacterium bovis BCG CFU. Frozen and prospectively collected clinical samples from patients suspected of having TB, with and without culture-confirmed TB, were also tested. For M. tuberculosis H37Rv, the LOD was 15.6 CFU/ml of sputum for Ultra versus 112.6 CFU/ml of sputum for Xpert, and for M. bovis BCG, it was 143.4 CFU/ml of sputum for Ultra versus 344 CFU/ml of sputum for Xpert. Ultra resulted in no false-positive RIF-R specimens, while Xpert resulted in two false-positive RIF-R specimens. All RIF-R-associated M. tuberculosis rpoB mutations tested were identified by Ultra. Testing on clinical sputum samples, Ultra versus Xpert, resulted in an overall sensitivity of 87.5% (95% confidence interval [CI], 82.1, 91.7) versus 81.0% (95% CI, 74.9, 86.2) and a sensitivity on sputum smear-negative samples of 78.9% (95% CI, 70.0, 86.1) versus 66.1% (95% CI, 56.4, 74.9). Both tests had a specificity of 98.7% (95% CI, 93.0, 100), and both had comparable accuracies for detection of RIF-R in these samples. Ultra should significantly improve TB detection, especially in patients with paucibacillary disease, and may provide more-reliable RIF-R detection. The Xpert MTB/RIF assay (Xpert), the first point-of-care assay for tuberculosis (TB), was endorsed by the World Health Organization in December 2010. Since then, 23 million Xpert tests have been procured in 130 countries. Although Xpert showed high overall sensitivity and specificity with pulmonary samples, its sensitivity has been lower with smear-negative pulmonary samples and extrapulmonary samples. In addition, the prediction of rifampin resistance (RIF-R) in paucibacillary samples and for a few rpoB mutations has resulted in both false-positive and false-negative results. The present study is the first demonstration of the design features and operational characteristics of an improved Xpert Ultra assay. This study also shows that the Ultra format overcomes many of the known shortcomings of Xpert. The new assay should significantly improve TB detection, especially in patients with paucibacillary disease, and provide more-reliable detection of RIF-R.
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Kohli M, Schiller I, Dendukuri N, Ryan H, Dheda K, Denkinger CM, Schumacher SG, Steingart KR. Xpert® MTB/RIF assay for extrapulmonary tuberculosis and rifampicin resistance. Cochrane Database Syst Rev 2017; 2017:CD012768. [PMCID: PMC6483559 DOI: 10.1002/14651858.cd012768] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
Abstract
This is a protocol for a Cochrane Review (Diagnostic test accuracy). The objectives are as follows:
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Affiliation(s)
- Mikashmi Kohli
- All India Institute of Medical Sciences (AIIMS)New DelhiIndia
| | - Ian Schiller
- McGill University Health Centre ‐ Research InstituteDivision of Clinical EpidemiologyMontrealCanada
| | - Nandini Dendukuri
- McGill University Health Centre ‐ Research InstituteDivision of Clinical EpidemiologyMontrealCanada
| | - Hannah Ryan
- Liverpool School of Tropical MedicineDepartment of Clinical SciencesLiverpoolUK
| | - Keertan Dheda
- University of Cape TownLung Infection and Immunity Unit, Department of MedicineCape TownSouth Africa
| | | | | | - Karen R Steingart
- Liverpool School of Tropical MedicineCochrane Infectious Diseases GroupPembroke PlaceLiverpoolUK
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Rufai SB, Singh A, Singh J, Kumar P, Sankar MM, Singh S. Diagnostic usefulness of Xpert MTB/RIF assay for detection of tuberculous meningitis using cerebrospinal fluid. J Infect 2017; 75:125-131. [PMID: 28501491 DOI: 10.1016/j.jinf.2017.04.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 04/01/2017] [Accepted: 04/05/2017] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Tuberculous meningitis (TBM) is the most severe form of extra-pulmonary tuberculosis (TB) due to association of diseases with high rates of mortality and morbidity. Diagnosis continues to be a clinical challenge as microbiological confirmation is rare and time consuming resulting in delayed treatment. Xpert MTB/RIF assay is a rapid and simple test, which has been endorsed by World Health Organization as an initial diagnostic test for the diagnosis of TBM. However, evidence still lacks for its performance on cerebrospinal fluid (CSF) for the diagnosis of TBM especially from India. METHODS A total of 267 CSF samples from patients with high clinico-radiological suspicion of TBM were included in this study. Ziehl-Neelsen (ZN) staining, BACTEC Mycobacterial Growth Indicator Tube (MGIT-960) culture system, and Xpert MTB/RIF assay (using cartridge version G4) were tested on all samples. RESULTS Of total 267 samples, all were negative for smear AFB and 52 (19.5%) were culture positive by MGIT-960 culture system. However, out of 52 (19.5%) cultures detected positive by MGIT-960, 5 (9.6%) were detected as resistant to rifampicin. Xpert MTB/RIF assay was positive in 38 (14.2%) samples and negative in 223 (83.5%) samples. Cartridge error was detected in 6 (2.2%) samples, which could not be repeated due to insufficient sample volume. The sensitivity and specificity of Xpert MTB/RIF assay in comparison to MGIT-960 was 55.1% (95%, CI: 40.2-69.3) and 94.8% (95%, CI: 90.9-97.4) respectively. Overall, Xpert MTB/RIF assay detected 38 (14.2%) as positive for MTB of which 4 (10.5%), 31 (81.6%) and 3 (7.9%) were found to be rifampicin resistant, sensitive and indeterminate respectively. CONCLUSION Xpert MTB/RIF assay showed lower sensitivity as compared to MGIT 960 culture for the diagnosis of TBM from CSF samples.
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Affiliation(s)
- Syed Beenish Rufai
- Division of Clinical Microbiology and Molecular Medicine, Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Amit Singh
- Division of Clinical Microbiology and Molecular Medicine, Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Jitendra Singh
- Division of Clinical Microbiology and Molecular Medicine, Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Parveen Kumar
- Division of Clinical Microbiology and Molecular Medicine, Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Manimuthu Mani Sankar
- Division of Clinical Microbiology and Molecular Medicine, Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Sarman Singh
- Division of Clinical Microbiology and Molecular Medicine, Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi, India.
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- Division of Clinical Microbiology and Molecular Medicine, Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi, India
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Utility of Second-Generation Line Probe Assay (Hain MTBDR plus) Directly on 2-Month Sputum Specimens for Monitoring Tuberculosis Treatment Response. J Clin Microbiol 2017; 55:1508-1515. [PMID: 28249999 PMCID: PMC5405268 DOI: 10.1128/jcm.00025-17] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 02/23/2017] [Indexed: 11/20/2022] Open
Abstract
The utility of a line probe assay (Genotype MTBDRplus) performed directly on 2-month sputa to monitor tuberculosis treatment response is unknown. We assessed if direct testing of 2-month sputa with MTBDRplus can predict 2-month culture conversion and long-term treatment outcome. Xpert MTB/RIF-confirmed rifampin-susceptible tuberculosis cases were recruited at tuberculosis diagnosis and followed up at 2 and 5 to 6 months. MTBDRplus was performed directly on 2-month sputa and on all positive cultured isolates at 2 and 5 to 6 months. We also investigated the association of a positive direct MTBDRplus at 2 months with subsequent unsuccessful tuberculosis treatment outcome (failure/death during treatment or subsequent disease recurrence). A total of 279 patients (62% of whom were HIV-1 coinfected) were recruited. Direct MTBDRplus at 2 months had a sensitivity of 78% (95% confidence interval [CI], 65 to 87) and specificity of 80% (95% CI, 74 to 84) to predict culture positivity at 2 months with a high negative predictive value of 93% (95% CI, 89 to 96). Inconclusive genotypic susceptibility results for both rifampin and isoniazid were seen in 26% of MTBDRplus tests performed directly on sputum. Compared to a reference of MTBDRplus performed on positive cultures, the false-positive resistance rate for direct testing of MTBDRplus on sputa was 4% for rifampin and 2% for isoniazid. While a positive 2-month smear was not significantly associated with an unsuccessful treatment outcome (adjusted odds ratio [aOR], 2.69; 95% CI, 0.88 to 8.21), a positive direct MTBDRplus at 2 months was associated with an unsuccessful outcome (aOR 2.87; 95% CI, 1.11 to 7.42). There is moderate utility of direct 2-month MTBDRplus to predict culture conversion at 2 months and also to predict an unfavorable outcome.
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Tiberi S, Carvalho ACC, Sulis G, Vaghela D, Rendon A, Mello FCDQ, Rahman A, Matin N, Zumla A, Pontali E. The cursed duet today: Tuberculosis and HIV-coinfection. Presse Med 2017; 46:e23-e39. [PMID: 28256380 DOI: 10.1016/j.lpm.2017.01.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 12/23/2016] [Accepted: 01/17/2017] [Indexed: 01/22/2023] Open
Abstract
The tuberculosis (TB) and HIV syndemic continues to rage and are a major public health concern worldwide. This deadly association raises complexity and represent a significant barrier towards TB elimination. TB continues to be the leading cause of death amongst HIV-infected people. This paper reports the challenges that lay ahead and outlines some of the current and future strategies that may be able to address this co-epidemic efficiently. Improved diagnostics, cheaper and more effective drugs, shorter treatment regimens for both drug-sensitive and drug-resistant TB are discussed. Also, special topics on drug interactions, TB-IRIS and TB relapse are also described. Notwithstanding the defeats and meagre investments, diagnosis and management of the two diseases have seen significant and unexpected improvements of late. On the HIV side, expansion of ART coverage, development of new updated guidelines aimed at the universal treatment of those infected, and the increasing availability of newer, more efficacious and less toxic drugs are an essential element to controlling the two epidemics. On the TB side, diagnosis of MDR-TB is becoming easier and faster thanks to the new PCR-based technologies, new anti-TB drugs active against both sensitive and resistant strains (i.e. bedaquiline and delamanid) have been developed and a few more are in the pipeline, new regimens (cheaper, shorter and/or more effective) have been introduced (such as the "Bangladesh regimen") or are being tested for MDR-TB and drug-sensitive-TB. However, still more resources will be required to implement an integrated approach, install new diagnostic tests, and develop simpler and shorter treatment regimens.
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Affiliation(s)
- Simon Tiberi
- Barts health NHS trust, Royal London hospital, division of infection, 80, Newark street, E1 2ES London, United Kingdom.
| | - Anna Cristina C Carvalho
- Oswaldo Cruz institute (IOC), laboratory of innovations in therapies, education and bioproducts, (LITEB), Fiocruz, Rio de Janeiro, Brazil.
| | - Giorgia Sulis
- University of Brescia, university department of infectious and tropical diseases, World health organization collaborating centre for TB/HIV co-infection and TB elimination, Brescia, Italy.
| | - Devan Vaghela
- Barts Health NHS Trust, Royal London hospital, department of respiratory medicine, 80, Newark street, E1 2ES London, United Kingdom.
| | - Adrian Rendon
- Hospital universitario de Monterrey, centro de investigación, prevención y tratamiento de infecciones respiratorias, Monterrey, Nuevo León UANL, Mexico.
| | - Fernanda C de Q Mello
- Federal university of Rio de Janeiro, instituto de Doenças do Tórax (IDT)/Clementino Fraga Filho hospital (CFFH), rua Professor Rodolpho Paulo Rocco, n° 255 - 1° Andar - Cidade Universitária - Ilha do Fundão, 21941-913, Rio De Janeiro, Brazil.
| | - Ananna Rahman
- Papworth hospital NHS foundation trust, department of respiratory medicine, Papworth Everard, Cambridge, United Kingdom.
| | - Nashaba Matin
- Barts Health NHS Trust, Royal London hospital, HIV medicine, infection and immunity, London, United Kingdom.
| | - Ali Zumla
- UCL hospitals NHS Foundation Trust, university college London, NIHR biomedical research centre, division of infection and immunity, London, United Kingdom.
| | - Emanuele Pontali
- Galliera hospital, department of infectious diseases, Genoa, Italy.
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Somily AM, Barry MA, Habib HA, Alotaibi FE, Al-Zamil FA, Khan MA, Sarwar MS, Bakhash ND, Alrabiaah AA, Shakoor ZA, Senok AC. Evaluation of GeneXpert MTB/RIF for detection of Mycobacterium tuberculosis complex and rpo B gene in respiratory and non-respiratory clinical specimens at a tertiary care teaching hospital in Saudi Arabia. Saudi Med J 2016; 37:1404-1407. [PMID: 27874159 PMCID: PMC5303782 DOI: 10.15537/smj.2016.12.15506] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 08/31/2016] [Indexed: 12/05/2022] Open
Abstract
OBJECTIVES To assess the performance of Xpert MTB/RIF, an automated molecular test for Mycobacterium tuberculosis (MTB) and resistance to rifampin (RIF), against smear microscopy and culture method for diagnosis of MTB infection. Methods: This is a retrospective analysis of 103 respiratory and 137 non-respiratory patient specimens suspected of tuberculosis at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia performed between April 2014 and March 2015. Each sample underwent smear microscopy, mycobacterial culture, and GeneXpert MTB/RIF test. Results: Fifteen out of 103 respiratory samples were smear and culture positive, whereas 9 out of 137 non-respiratory samples were smear positive. Out of 9 smear positive specimens, 8 were also culture positive. All 15 culture positive respiratory samples were detected by Xpert MTB/RIF (sensitivity and positive predictive value [PPV]=100%). Similarly, all 8 culture positive non-respiratory specimens were identified by Xpert MTB/RIF (sensitivity 100%; PPV 88.8%). The Xpert MTB/RIF detected only one false positive result in 88 smear negative respiratory specimens (specificity 98.9%; negative predictive value [NPV]= 100%). All 125 smear negative non-respiratory specimens tested negative by culture and Xpert MTB/RIF (sensitivity, specificity, PPV, NPV= 100%). Conclusion: The performance of Xpert MTB/RIF was comparable to the gold standard culture method for identification of MTB in both respiratory and non-respiratory clinical specimens.
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Affiliation(s)
- Ali M Somily
- Department of Pathology/Microbiology, College of Medicine, King Khalid University Hospital, King Saud University, Riyadh, Kingdom of Saudi Arabia. E-mail.
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Walusimbi S, Kwesiga B, Rodrigues R, Haile M, de Costa A, Bogg L, Katamba A. Cost-effectiveness analysis of microscopic observation drug susceptibility test versus Xpert MTB/Rif test for diagnosis of pulmonary tuberculosis in HIV patients in Uganda. BMC Health Serv Res 2016; 16:563. [PMID: 27724908 PMCID: PMC5057383 DOI: 10.1186/s12913-016-1804-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 09/28/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Microscopic Observation Drug Susceptibility (MODS) and Xpert MTB/Rif (Xpert) are highly sensitive tests for diagnosis of pulmonary tuberculosis (PTB). This study evaluated the cost effectiveness of utilizing MODS versus Xpert for diagnosis of active pulmonary TB in HIV infected patients in Uganda. METHODS A decision analysis model comparing MODS versus Xpert for TB diagnosis was used. Costs were estimated by measuring and valuing relevant resources required to perform the MODS and Xpert tests. Diagnostic accuracy data of the tests were obtained from systematic reviews involving HIV infected patients. We calculated base values for unit costs and varied several assumptions to obtain the range estimates. Cost effectiveness was expressed as costs per TB patient diagnosed for each of the two diagnostic strategies. Base case analysis was performed using the base estimates for unit cost and diagnostic accuracy of the tests. Sensitivity analysis was performed using a range of value estimates for resources, prevalence, number of tests and diagnostic accuracy. RESULTS The unit cost of MODS was US$ 6.53 versus US$ 12.41 of Xpert. Consumables accounted for 59 % (US$ 3.84 of 6.53) of the unit cost for MODS and 84 % (US$10.37 of 12.41) of the unit cost for Xpert. The cost effectiveness ratio of the algorithm using MODS was US$ 34 per TB patient diagnosed compared to US$ 71 of the algorithm using Xpert. The algorithm using MODS was more cost-effective compared to the algorithm using Xpert for a wide range of different values of accuracy, cost and TB prevalence. The cost (threshold value), where the algorithm using Xpert was optimal over the algorithm using MODS was US$ 5.92. CONCLUSIONS MODS versus Xpert was more cost-effective for the diagnosis of PTB among HIV patients in our setting. Efforts to scale-up MODS therefore need to be explored. However, since other non-economic factors may still favour the use of Xpert, the current cost of the Xpert cartridge still needs to be reduced further by more than half, in order to make it economically competitive with MODS.
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Affiliation(s)
- Simon Walusimbi
- Department of Microbiology, Makerere University College of Health Sciences, Kampala, Uganda.,Department of Public Health Sciences, Karolinska Institute, Solna, Sweden
| | | | - Rashmi Rodrigues
- Department of Public Health Sciences, Karolinska Institute, Solna, Sweden
| | - Melles Haile
- Department of Microbiology, Public Health Agency of Sweden, Solna, Sweden
| | - Ayesha de Costa
- Department of Public Health Sciences, Karolinska Institute, Solna, Sweden
| | - Lennart Bogg
- Department of Public Health Sciences, Karolinska Institute, Solna, Sweden.,School of Health, Care and social Welfare, Malardalen University, Vasteras, Sweden
| | - Achilles Katamba
- Department of Medicine, Clinical Epidemiology Unit, Makerere University, College of Health Sciences, Kampala, Uganda.
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Nahid P, Dorman SE, Alipanah N, Barry PM, Brozek JL, Cattamanchi A, Chaisson LH, Chaisson RE, Daley CL, Grzemska M, Higashi JM, Ho CS, Hopewell PC, Keshavjee SA, Lienhardt C, Menzies R, Merrifield C, Narita M, O'Brien R, Peloquin CA, Raftery A, Saukkonen J, Schaaf HS, Sotgiu G, Starke JR, Migliori GB, Vernon A. Official American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America Clinical Practice Guidelines: Treatment of Drug-Susceptible Tuberculosis. Clin Infect Dis 2016; 63:e147-e195. [PMID: 27516382 DOI: 10.1093/cid/ciw376] [Citation(s) in RCA: 641] [Impact Index Per Article: 80.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 06/06/2016] [Indexed: 02/06/2023] Open
Abstract
The American Thoracic Society, Centers for Disease Control and Prevention, and Infectious Diseases Society of America jointly sponsored the development of this guideline for the treatment of drug-susceptible tuberculosis, which is also endorsed by the European Respiratory Society and the US National Tuberculosis Controllers Association. Representatives from the American Academy of Pediatrics, the Canadian Thoracic Society, the International Union Against Tuberculosis and Lung Disease, and the World Health Organization also participated in the development of the guideline. This guideline provides recommendations on the clinical and public health management of tuberculosis in children and adults in settings in which mycobacterial cultures, molecular and phenotypic drug susceptibility tests, and radiographic studies, among other diagnostic tools, are available on a routine basis. For all recommendations, literature reviews were performed, followed by discussion by an expert committee according to the Grading of Recommendations, Assessment, Development and Evaluation methodology. Given the public health implications of prompt diagnosis and effective management of tuberculosis, empiric multidrug treatment is initiated in almost all situations in which active tuberculosis is suspected. Additional characteristics such as presence of comorbidities, severity of disease, and response to treatment influence management decisions. Specific recommendations on the use of case management strategies (including directly observed therapy), regimen and dosing selection in adults and children (daily vs intermittent), treatment of tuberculosis in the presence of HIV infection (duration of tuberculosis treatment and timing of initiation of antiretroviral therapy), as well as treatment of extrapulmonary disease (central nervous system, pericardial among other sites) are provided. The development of more potent and better-tolerated drug regimens, optimization of drug exposure for the component drugs, optimal management of tuberculosis in special populations, identification of accurate biomarkers of treatment effect, and the assessment of new strategies for implementing regimens in the field remain key priority areas for research. See the full-text online version of the document for detailed discussion of the management of tuberculosis and recommendations for practice.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Julie M Higashi
- Tuberculosis Control Section, San Francisco Department of Public Health, California
| | - Christine S Ho
- Division of Tuberculosis Elimination, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | | | | | | | | | - Masahiro Narita
- Tuberculosis Control Program, Seattle and King County Public Health, and University of Washington, Seattle
| | - Rick O'Brien
- Ethics Advisory Group, International Union Against TB and Lung Disease, Paris, France
| | | | | | | | - H Simon Schaaf
- Department of Paediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
| | | | | | - Giovanni Battista Migliori
- WHO Collaborating Centre for TB and Lung Diseases, Fondazione S. Maugeri Care and Research Institute, Tradate, Italy
| | - Andrew Vernon
- Division of Tuberculosis Elimination, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia
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Madico G, Mpeirwe M, White L, Vinhas S, Orr B, Orikiriza P, Miller NS, Gaeddert M, Mwanga-Amumpaire J, Palaci M, Kreiswirth B, Straight J, Dietze R, Boum Y, Jones-López EC. Detection and Quantification of Mycobacterium tuberculosis in the Sputum of Culture-Negative HIV-infected Pulmonary Tuberculosis Suspects: A Proof-of-Concept Study. PLoS One 2016; 11:e0158371. [PMID: 27391604 PMCID: PMC4938528 DOI: 10.1371/journal.pone.0158371] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 06/14/2016] [Indexed: 12/11/2022] Open
Abstract
RATIONALE Rapid diagnosis of pulmonary tuberculosis (TB) is critical for timely initiation of treatment and interruption of transmission. Yet, despite recent advances, many patients remain undiagnosed. Culture, usually considered the most sensitive diagnostic method, is sub-optimal for paucibacillary disease. METHODS We evaluated the Totally Optimized PCR (TOP) TB assay, a new molecular test that we hypothesize is more sensitive than culture. After pre-clinical studies, we estimated TOP's per-patient sensitivity and specificity in a convenience sample of 261 HIV-infected pulmonary TB suspects enrolled into a TB diagnostic study in Mbarara, Uganda against MGIT culture, Xpert MTB/RIF and a composite reference standard. We validated results with a confirmatory PCR used for sequencing M. tuberculosis. MEASUREMENTS AND RESULTS Using culture as reference, TOP had 100% sensitivity but 35% specificity. Against a composite reference standard, the sensitivity of culture (27%) and Xpert MTB/RIF (27%) was lower than TOP (99%), with similar specificity (100%, 98% and 87%, respectively). In unadjusted analyses, culture-negative/TOP-positive patients were more likely to be older (P<0·001), female (P<0·001), have salivary sputum (P = 0·05), sputum smear-negative (P<0.001) and less advanced disease on chest radiograph (P = 0.05). M. tuberculosis genotypes identified in sputum by DNA sequencing exhibit differential growth in culture. CONCLUSIONS These findings suggest that the TOP TB assay is accurately detecting M. tuberculosis DNA in the sputum of culture-negative tuberculosis suspects. Our results require prospective validation with clinical outcomes. If the operating characteristics of the TOP assay are confirmed in future studies, it will be justified as a "TB rule out" test.
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Affiliation(s)
- Guillermo Madico
- Section of Infectious Diseases, Department of Medicine, Boston Medical Center and Boston University School of Medicine, Boston, Massachusetts, United States of America
- Thisis Diagnostics Inc., Boston, Massachusetts, United States of America
| | - Moses Mpeirwe
- Epicentre, Médecins sans Frontières, Mbarara, Uganda
- Mbarara University of Science and Technology, Mbarara, Uganda
| | - Laura White
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts, United States of America
| | - Solange Vinhas
- Núcleo de Doenças Infecciosas, Universidade Federal do Espírito Santo, Vitória, Brazil
| | - Beverley Orr
- Clinical Microbiology Laboratory, Boston Medical Center, Boston, Massachusetts, United States of America
| | | | - Nancy S. Miller
- Clinical Microbiology Laboratory, Boston Medical Center, Boston, Massachusetts, United States of America
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Mary Gaeddert
- Section of Infectious Diseases, Department of Medicine, Boston Medical Center and Boston University School of Medicine, Boston, Massachusetts, United States of America
| | | | - Moises Palaci
- Núcleo de Doenças Infecciosas, Universidade Federal do Espírito Santo, Vitória, Brazil
| | - Barry Kreiswirth
- Public Health Research Institute (PHRI) – Rutgers University, Newark, New Jersey, United States of America
| | - Joe Straight
- Thisis Diagnostics Inc., Boston, Massachusetts, United States of America
| | - Reynaldo Dietze
- Núcleo de Doenças Infecciosas, Universidade Federal do Espírito Santo, Vitória, Brazil
| | - Yap Boum
- Epicentre, Médecins sans Frontières, Mbarara, Uganda
| | - Edward C. Jones-López
- Section of Infectious Diseases, Department of Medicine, Boston Medical Center and Boston University School of Medicine, Boston, Massachusetts, United States of America
- Thisis Diagnostics Inc., Boston, Massachusetts, United States of America
- * E-mail:
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Al-Darraji HAA, Altice FL, Kamarulzaman A. Undiagnosed pulmonary tuberculosis among prisoners in Malaysia: an overlooked risk for tuberculosis in the community. Trop Med Int Health 2016; 21:1049-1058. [DOI: 10.1111/tmi.12726] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
| | - Frederick L. Altice
- Centre of Excellence for Research in AIDS; University of Malaya; Kuala Lumpur Malaysia
- AIDS Program; Department of Medicine; Yale University School of Medicine; New Haven CT USA
- Department of Microbial Epidemiology; Yale University School of Public Health; New Haven CT USA
| | - Adeeba Kamarulzaman
- Centre of Excellence for Research in AIDS; University of Malaya; Kuala Lumpur Malaysia
- AIDS Program; Department of Medicine; Yale University School of Medicine; New Haven CT USA
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Ho J, Nguyen PTB, Nguyen TA, Tran KH, Van Nguyen S, Nguyen NV, Nguyen HB, Luu KB, Fox GJ, Marks GB. Reassessment of the positive predictive value and specificity of Xpert MTB/RIF: a diagnostic accuracy study in the context of community-wide screening for tuberculosis. THE LANCET. INFECTIOUS DISEASES 2016; 16:1045-1051. [PMID: 27289387 DOI: 10.1016/s1473-3099(16)30067-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 04/21/2016] [Accepted: 04/22/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND Community-wide screening for tuberculosis with Xpert MTB/RIF as a primary screening tool overcomes some of the limitations of conventional screening. However, concerns exist about the low positive predictive value of this test in screening settings. We did a cross-sectional assessment of this diagnostic test to directly estimate the actual positive predictive value of Xpert MTB/RIF when used in the setting of community-wide screening for tuberculosis, and to draw an inference about the specificity of the test for tuberculosis detection. METHODS Field staff visited households in 60 randomly selected villages in Ca Mau province, Vietnam. We included people aged 15 years or older who provided written informed consent and were able to produce 0·5 mL or more of sputum, irrespective of reported symptoms. Participants were tested with Xpert MTB/RIF, then those with positive results had two further sputum samples tested for smear microscopy and culture, and underwent chest radiography at the provincial TB Health Center. The positive predictive value of Xpert MTB/RIF was compared against two reference standards for tuberculosis diagnosis-a positive sputum culture for Mycobacterium tuberculosis, and a positive sputum culture or a chest radiograph consistent with active pulmonary tuberculosis. We then calculated the specificity of Xpert MTB/RIF for tuberculosis detection on the basis of these positive predictive values and disease prevalence in this setting. FINDINGS 43 435 adults consented to screening with Xpert MTB/RIF. Sputum samples of 0·5 mL or greater were collected from 23 202 participants, producing 22 673 valid results. 169 participants had positive Xpert MTB/RIF results (0·39% of those screened and 0·75% of those with valid sputum results). The positive predictive value of Xpert MTB/RIF was 61·0% (95% CI 52·8-68·7) when compared against a positive sputum culture and 83·9% (76·8-89·2) when compared against a positive sputum culture or chest radiograph consistent with active tuberculosis. On the basis of these positive predictive values, the specificity of Xpert MTB/RIF was determined to be between 99·78% (95% CI 99·71-99·84) and 99·93% (99·88-99·96). INTERPRETATION The positive predictive value and specificity of Xpert MTB/RIF in the context of community-wide screening for tuberculosis is substantially higher than that predicted in previous studies. Our findings support the potential role of Xpert MTB/RIF as a primary screening tool to detect prevalent cases of tuberculosis in the community. FUNDING Australian National Health and Medical Research Council.
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Affiliation(s)
- Jennifer Ho
- Woolcock Institute of Medical Research, University of Sydney, Sydney, NSW, Australia; South Western Sydney Clinical School, University of New South Wales, Sydney, NSW, Australia.
| | | | | | - Khoa Hien Tran
- Ca Mau Centre for Social Disease Prevention, Ca Mau, Vietnam
| | - Son Van Nguyen
- Ca Mau Centre for Social Disease Prevention, Ca Mau, Vietnam
| | | | - Hoa Binh Nguyen
- National Tuberculosis Program, Hanoi, Vietnam; Centre for Operational Research, International Union Against Tuberculosis and Lung Disease, Paris, France
| | - Khanh Boi Luu
- Woolcock Institute of Medical Research, Hanoi, Vietnam
| | - Greg J Fox
- Woolcock Institute of Medical Research, University of Sydney, Sydney, NSW, Australia; Central Clinical School, Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| | - Guy B Marks
- Woolcock Institute of Medical Research, University of Sydney, Sydney, NSW, Australia; South Western Sydney Clinical School, University of New South Wales, Sydney, NSW, Australia
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Theron G, Venter R, Calligaro G, Smith L, Limberis J, Meldau R, Chanda D, Esmail A, Peter J, Dheda K. Xpert MTB/RIF Results in Patients With Previous Tuberculosis: Can We Distinguish True From False Positive Results? Clin Infect Dis 2016; 62:995-1001. [PMID: 26908793 PMCID: PMC4803105 DOI: 10.1093/cid/civ1223] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 12/22/2015] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Patients with previous tuberculosis may have residual DNA in sputum that confounds nucleic acid amplification tests such as Xpert MTB/RIF. Little is known about the frequency of Xpert-positive, culture-negative ("false positive") results in retreatment patients, whether these are distinguishable from true positives, and whether Xpert's automated filter-based wash step reduces false positivity by removing residual DNA associated with nonintact cells. METHODS Pretreatment patients (n = 2889) with symptoms of tuberculosis from Cape Town, South Africa, underwent a sputum-based liquid culture and Xpert. We also compared Xpert results from dilutions of intact or heat-lysed and mechanically lysed bacilli. RESULTS Retreatment cases were more likely to be Xpert false-positive (45/321 Xpert-positive retreatment cases were false-positive) than new cases (40/461) (14% [95% confidence interval {CI}, 10%-18%] vs 8% [95% CI, 6%-12%];P= .018). Fewer years since treatment completion (adjusted odds ratio [aOR], 0.85 [95% CI, .73-.99]), less mycobacterial DNA (aOR, 1.14 [95% CI, 1.03-1.27] per cycle threshold [CT]), and a chest radiograph not suggestive of active tuberculosis (aOR, 0.22 [95% CI, .06-.82]) were associated with false positivity. CThad suboptimal accuracy for false positivity: 46% of Xpert-positives with CT> 30 would be false positive, although 70% of false positives would be missed. CT's predictive ability (area under the curve, 0.83 [95% CI, .76-.90]) was not improved by additional variables. Xpert detected nonviable, nonintact bacilli without a change in CTvs controls. CONCLUSIONS One in 7 Xpert-positive retreatment patients were culture negative and potentially false positive. False positivity was associated with recent previous tuberculosis, high CT, and a chest radiograph not suggestive of active tuberculosis. Clinicians may consider awaiting confirmatory testing in retreatment patients with CT> 30; however, most false positives fall below this cut-point. Xpert can detect DNA from nonviable, nonintact bacilli.
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Affiliation(s)
- Grant Theron
- Lung Infection and Immunity Unit, Division of Pulmonology and University of Cape Town Lung Institute, Department of Medicine, University of Cape Town and
- DST/NRF of Excellence for Biomedical Tuberculosis Research, and MRC Centre for Molecular and Cellular Biology, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa
| | - Rouxjeane Venter
- DST/NRF of Excellence for Biomedical Tuberculosis Research, and MRC Centre for Molecular and Cellular Biology, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa
| | - Greg Calligaro
- Lung Infection and Immunity Unit, Division of Pulmonology and University of Cape Town Lung Institute, Department of Medicine, University of Cape Townand
| | - Liezel Smith
- Lung Infection and Immunity Unit, Division of Pulmonology and University of Cape Town Lung Institute, Department of Medicine, University of Cape Townand
| | - Jason Limberis
- Lung Infection and Immunity Unit, Division of Pulmonology and University of Cape Town Lung Institute, Department of Medicine, University of Cape Townand
| | - Richard Meldau
- Lung Infection and Immunity Unit, Division of Pulmonology and University of Cape Town Lung Institute, Department of Medicine, University of Cape Townand
| | - Duncan Chanda
- Lung Infection and Immunity Unit, Division of Pulmonology and University of Cape Town Lung Institute, Department of Medicine, University of Cape Town and
- Institute for Medical Research and Training, Lusaka, Zambia
| | - Aliasgar Esmail
- Lung Infection and Immunity Unit, Division of Pulmonology and University of Cape Town Lung Institute, Department of Medicine, University of Cape Townand
| | - Jonny Peter
- Lung Infection and Immunity Unit, Division of Pulmonology and University of Cape Town Lung Institute, Department of Medicine, University of Cape Townand
| | - Keertan Dheda
- Lung Infection and Immunity Unit, Division of Pulmonology and University of Cape Town Lung Institute, Department of Medicine, University of Cape Town and
- Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, South Africa
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Diagnostic Accuracy of the Small Membrane Filtration Method for Diagnosis of Pulmonary Tuberculosis in a High-HIV-Prevalence Setting. J Clin Microbiol 2016; 54:1520-1527. [PMID: 27030493 DOI: 10.1128/jcm.00017-16] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 03/21/2016] [Indexed: 11/20/2022] Open
Abstract
Sputum acid-fast bacilli (AFB) smear microscopy has suboptimal sensitivity but remains the most commonly used laboratory test to diagnose pulmonary tuberculosis (TB). We prospectively evaluated the small membrane filtration (SMF) method that concentrates AFB in a smaller area to facilitate detection to improve the diagnostic performance of microscopy. We enrolled adults with suspicion of pulmonary TB from health facilities in southwestern Uganda. Clinical history, physical examination, and 3 sputum samples were obtained for direct fluorescent AFB smear, SMF, Xpert MTB/RIF, and MGIT culture media. Sensitivity and specificity were estimated for SMF, AFB smear, and Xpert MTB/RIF, using MGIT as the reference standard. The analysis was stratified according to HIV status. From September 2012 to April 2014, 737 participants were included in the HIV-infected stratum (146 [20.5%] were culture positive) and 313 were in the HIV-uninfected stratum (85 [28%] were culture positive). In HIV-infected patients, the sensitivity of a single SMF was 67.4% (95% confidence interval [CI], 59.9% to 74.1%); for AFB, 68.0% (95% CI, 60.6% to 74.6%); and for Xpert MTB/RIF, 91.0% (95% CI, 85.0% to 94.8%). In HIV-uninfected patients, the corresponding sensitivities were 72.5% (95% CI, 62.1% to 80.9%), 80.3% (95% CI, 70.8% to 87.2%), and 93.5% (95% CI, 85.7% to 97.2%). The specificity for all 3 tests in both HIV groups was ≥96%. In this setting, the SMF method did not improve the diagnostic accuracy of sputum AFB. The Xpert MTB/RIF assay performed well in both HIV-infected and -uninfected groups.
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Barnard DA, Irusen EM, Bruwer JW, Plekker D, Whitelaw AC, Deetlefs JD, Koegelenberg CFN. The utility of Xpert MTB/RIF performed on bronchial washings obtained in patients with suspected pulmonary tuberculosis in a high prevalence setting. BMC Pulm Med 2015; 15:103. [PMID: 26377395 PMCID: PMC4573925 DOI: 10.1186/s12890-015-0086-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 07/30/2015] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Xpert MTB/RIF has been shown to have a superior sensitivity to microscopy for acid fast bacilli (AFB) in sputum and has been recommended as a standard first line investigation for pulmonary tuberculosis (PTB). Bronchoscopy is a valuable tool in diagnosing PTB in sputum negative patients. There is limited data on the utility of Xpert MTB/RIF performed on bronchial lavage specimens. Our aim was to evaluate the diagnostic efficiency of Xpert MTB/RIF performed on bronchial washings in sputum scarce/negative patients with suspected PTB. METHODS All patients with a clinical and radiological suspicion of PTB who underwent bronchoscopy between January 2013 and April 2014 were included. The diagnostic efficiencies of Xpert MTB/RIF and microscopy for AFB were compared to culture for Mycobacterium tuberculosis. RESULTS Thirty nine of 112 patients were diagnosed with culture-positive PTB. Xpert MTB/RIF was positive in 36/39 with a sensitivity of 92.3% (95% CI 78-98%) for PTB, which was superior to that of smear microscopy (41%; 95% CI 26.0-57.8%, p = 0.005). The specificities of Xpert MTB/RIF and smear microscopy were 87.7% (95% CI 77.4-93.9%) and 98.6% (95% CI 91.6%-99.9%) respectively. Xpert MTB/RIF had a positive predictive value of 80% (95% CI; 65-89.9%) and negative predictive value of 95.5% (95% CI 86.6-98.8%). 3/9 patients with Xpert MTB/RIF positive culture negative results were treated for PTB based on clinical and radiological findings. CONCLUSION Xpert MTB/RIF has a higher sensitivity than smear microscopy and similar specificity for the immediate confirmation of PTB in specimens obtained by bronchial washing, and should be utilised in patients with a high suspicion of pulmonary tuberculosis.
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Affiliation(s)
- Dewald A Barnard
- Divisions of Pulmonology, Department of Medicine, Stellenbosch University, PO Box 19063, 7505, Cape Town, South Africa. .,Tygerberg Academic Hospital, Cape Town, South Africa.
| | - Elvis M Irusen
- Divisions of Pulmonology, Department of Medicine, Stellenbosch University, PO Box 19063, 7505, Cape Town, South Africa. .,Tygerberg Academic Hospital, Cape Town, South Africa.
| | - Johannes W Bruwer
- Divisions of Pulmonology, Department of Medicine, Stellenbosch University, PO Box 19063, 7505, Cape Town, South Africa. .,Tygerberg Academic Hospital, Cape Town, South Africa.
| | | | - Andrew C Whitelaw
- Tygerberg Academic Hospital, Cape Town, South Africa. .,Division of Medical Microbiology and Immunology, Department of Pathology, Stellenbosch University, Cape Town, South Africa. .,National Health Laboratory Services, Cape Town, South Africa.
| | | | - Coenraad F N Koegelenberg
- Divisions of Pulmonology, Department of Medicine, Stellenbosch University, PO Box 19063, 7505, Cape Town, South Africa. .,Tygerberg Academic Hospital, Cape Town, South Africa.
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Calligaro GL, Theron G, Khalfey H, Peter J, Meldau R, Matinyenya B, Davids M, Smith L, Pooran A, Lesosky M, Esmail A, Miller MG, Piercy J, Michell L, Dawson R, Raine RI, Joubert I, Dheda K. Burden of tuberculosis in intensive care units in Cape Town, South Africa, and assessment of the accuracy and effect on patient outcomes of the Xpert MTB/RIF test on tracheal aspirate samples for diagnosis of pulmonary tuberculosis: a prospective burden of disease study with a nested randomised controlled trial. THE LANCET RESPIRATORY MEDICINE 2015. [PMID: 26208996 DOI: 10.1016/s2213-2600(15)00198-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND There are few prospective data about the incidence and mortality associated with pulmonary tuberculosis in intensive care units (ICUs), and none on the accuracy and clinical effect of the Xpert-MTB/RIF assay in this setting. We aimed to measure the frequency of culture-positive tuberculosis in ICUs in Cape Town, South Africa and to assess the performance and effect on patient outcomes of Xpert MTB/RIF versus smear microscopy for diagnosis of tuberculosis. METHODS We did a prospective burden of disease study with a randomised controlled substudy at the ICUs of four hospitals in Cape Town. Mechanically ventilated adults (≥18 years) with suspected pulmonary tuberculosis admitted between Aug 1, 2010, and July 31, 2013 (irrespective of the reason for admission), were prospectively investigated by culture, and by Xpert-MTB/RIF testing or smear microscopy, of tracheal aspirate samples. In the substudy, patients were randomly assigned (1:1), via a computer-generated allocation list, to smear microscopy or Xpert MTB/RIF. Participants, caregivers, and outcome assessors were not masked to group assignment. Only the laboratory staff were blinded to the clinical details of the participants. In November, 2012, Xpert MTB/RIF was adopted as the initial diagnostic test for respiratory samples in Western Cape province. Thereafter, patients received Xpert MTB/MIF and culture as standard of care. For the whole study cohort, the primary outcome was the frequency of bacteriologically confirmed tuberculosis. The primary endpoint of the randomised substudy was the proportion of culture-positive patients on treatment at 48 h after enrolment. The randomised substudy is registered with ClinicalTrials.gov, number NCT01530568. FINDINGS We investigated 341 patients for suspected pulmonary tuberculosis out of a total of 2309 ICU admissions. 46 (15%) of 317 patients included in the final analysis had a positive test for tuberculosis (Xpert MTB/RIF or culture). Culture-positive patients who failed to initiate treatment (adjusted HR 4·49, 95% CI 1·45-13·89) or who received inotropes (4·33, 1·49-12·60) were more likely to die. However, tuberculosis status was not associated with 28-day or 90-day mortality. In the substudy, we randomly assigned 115 patients to smear microscopy and 111 to Xpert MTB/RIF. Smear microscopy detected six (43%) of 14 culture-positive patients, and Xpert MTB/RIF detected 11 (100%) of 11 culture-positive patients (p=0·002). The proportion of culture-positive patients on treatment at 48 h was higher in the Xpert MTB/RIF group than in the smear microscopy group (11 [92%] of 12 vs nine [53%] of 17; p=0·043), although use of Xpert MTB/RIF had no effect on mortality or other patient outcomes. INTERPRETATION Tuberculosis is fairly common in ICUs in high-burden settings, and clinicians should screen and test patients for tuberculosis with Xpert MTB/RIF where available. This test improves diagnostic yield and rates of treatment initiation, and reduces unnecessary treatment, but might not increase the total number of patients on treatment when empirical treatment is widely used. A suspected diagnosis of pulmonary tuberculosis should not exclude patients from ICU care in resource-limited settings because mortality is unaffected by the presence of this disease. FUNDING European and Developing Countries Clinical Trials Partnership, South African Medical Research Council, and the Discovery Foundation.
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Affiliation(s)
- Gregory L Calligaro
- Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - Grant Theron
- Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - Hoosain Khalfey
- Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - Jonathan Peter
- Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - Richard Meldau
- Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - Brian Matinyenya
- Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - Malika Davids
- Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - Liezel Smith
- Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - Anil Pooran
- Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - Maia Lesosky
- Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Aliasgar Esmail
- Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - Malcolm G Miller
- Division of Critical Care, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - Jenna Piercy
- Division of Critical Care, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - Lancelot Michell
- Division of Critical Care, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - Rodney Dawson
- Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - Richard I Raine
- Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - Ivan Joubert
- Division of Critical Care, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
| | - Keertan Dheda
- Lung Infection and Immunity Unit, Division of Pulmonology and UCT Lung Institute, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa.
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Review of nucleic acid amplification tests and clinical prediction rules for diagnosis of tuberculosis in acute care facilities. Infect Control Hosp Epidemiol 2015; 36:1215-25. [PMID: 26166303 DOI: 10.1017/ice.2015.145] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Tuberculosis (TB) remains an important cause of hospitalization and mortality in the United States. Prevention of TB transmission in acute care facilities relies on prompt identification and implementation of airborne isolation, rapid diagnosis, and treatment of presumptive pulmonary TB patients. In areas with low TB burden, this strategy may result in inefficient utilization of airborne infection isolation rooms (AIIRs). We reviewed TB epidemiology and diagnostic approaches to inform optimal TB detection in low-burden settings. Published clinical prediction rules for individual studies have a sensitivity ranging from 81% to 100% and specificity ranging from 14% to 63% for detection of culture-positive pulmonary TB patients admitted to acute care facilities. Nucleic acid amplification tests (NAATs) have a specificity of >98%, and the sensitivity of NAATs varies by acid-fast bacilli sputum smear status (positive smear, ≥95%; negative smear, 50%-70%). We propose an infection prevention strategy using a clinical prediction rule to identify patients who warrant diagnostic evaluation for TB in an AIIR with an NAAT. Future studies are needed to evaluate whether use of clinical prediction rules and NAATs results in optimized utilization of AIIRs and improved detection and treatment of presumptive pulmonary TB patients.
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van Kampen SC, Susanto NH, Simon S, Astiti SD, Chandra R, Burhan E, Farid MN, Chittenden K, Mustikawati DE, Alisjahbana B. Effects of Introducing Xpert MTB/RIF on Diagnosis and Treatment of Drug-Resistant Tuberculosis Patients in Indonesia: A Pre-Post Intervention Study. PLoS One 2015; 10:e0123536. [PMID: 26075722 PMCID: PMC4468115 DOI: 10.1371/journal.pone.0123536] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 02/19/2015] [Indexed: 12/01/2022] Open
Abstract
Background In March 2012, the Xpert MTB/RIF assay (Xpert) was introduced in three provincial public hospitals in Indonesia as a novel diagnostic to detect tuberculosis and rifampicin resistance among high risk individuals. Objective This study assessed the effects of using Xpert in place of conventional solid and liquid culture and drug-susceptibility testing on case detection rates, treatment initiation rates, and health system delays among drug-resistant tuberculosis (TB) patients. Methods Cohort data on registration, test results and treatment initiation were collected from routine presumptive patient registers one year before and one year after Xpert was introduced. Proportions of case detection and treatment initiation were compared using the Pearson Chi square test and median time delays using the Mood’s Median test. Results A total of 975 individuals at risk of drug-resistant TB were registered in the pre-intervention year and 1,442 in the post-intervention year. After Xpert introduction, TB positivity rate increased by 15%, while rifampicin resistance rate reduced by 23% among TB positive cases and by 9% among all tested. Second-line TB treatment initiation rate among rifampicin resistant patients increased by 19%. Time from client registration to diagnosis was reduced by 74 days to a median of a single day (IQR 0–4) and time from diagnosis to treatment start was reduced by 27 days to a median of 15 days (IQR 7–51). All findings were significant with p<0.001. Conclusion Compared to solid and liquid culture and drug-susceptibility testing, Xpert detected more TB and less rifampicin resistance, increased second-line treatment initiation rates and shortened time to diagnosis and treatment. This test holds promise to improve rapid case finding and management of drug-resistant TB patients in Indonesia.
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Affiliation(s)
- Sanne C. van Kampen
- Access to Laboratory Services Team, KNCV Tuberculosis Foundation, The Hague, the Netherlands
- * E-mail:
| | - Nugroho H. Susanto
- Medical Faculty, Universitas Padjadjaran, Bandung, Indonesia
- Tuberculosis Operational Research Group, Ministry of Health, Jakarta, Indonesia
| | - Sumanto Simon
- Tuberculosis Operational Research Group, Ministry of Health, Jakarta, Indonesia
- Medical Faculty, Universitas Atmadjaja, Jakarta, Indonesia
| | - Shinta D. Astiti
- Tuberculosis Operational Research Group, Ministry of Health, Jakarta, Indonesia
| | - Roni Chandra
- Laboratory Team TB CARE I, KNCV Tuberculosis Foundation, Jakarta, Indonesia
| | - Erlina Burhan
- Department of Lung and Respiratory Health, Persahabatan Hospital, Jakarta, Indonesia
| | - Muhammad N. Farid
- Tuberculosis Operational Research Group, Ministry of Health, Jakarta, Indonesia
- Sub-Directorate Statistics and Design, Central Bureau of Statistics, Jakarta, Indonesia
| | - Kendra Chittenden
- Health Division, United States Agency for International Development, Jakarta, Indonesia
| | - Dyah E. Mustikawati
- National Tuberculosis Control Program, Ministry of Health, Jakarta, Indonesia
| | - Bachti Alisjahbana
- Medical Faculty, Universitas Padjadjaran, Bandung, Indonesia
- Tuberculosis Operational Research Group, Ministry of Health, Jakarta, Indonesia
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Arora D, Jindal N, Bansal R, Arora S. Rapid Detection of Mycobacterium tuberculosis in Sputum Samples by Cepheid Xpert Assay: A Clinical Study. J Clin Diagn Res 2015; 9:DC03-5. [PMID: 26155475 DOI: 10.7860/jcdr/2015/11352.5935] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Accepted: 10/17/2014] [Indexed: 11/24/2022]
Abstract
BACKGROUND AND OBJECTIVE Tuberculosis (TB) is one of the commonest opportunistic infection and the leading cause of death in HIV patients in developing countries. HIV infection is a well recognised risk factor for both activation of initial infection and reactivation of latent infection. This study was done to find out the co-prevalence and the trend of HIV infection among tuberculosis patients and to determine the prevalence of MDR Tuberculosis in HIV positive patients using Xpert MTB/RIF assay (Cepheid, Sunnyvale, CA, United States). MATERIALS AND METHODS The sputum samples are received from five districts of Punjab. Sputum samples of the patients with symptoms suggestive of pulmonary tuberculosis including both new cases and on treatment are received from the various district and civil hospitals of five districts. Sputum specimen was processed for TB detection by Cartridge Based Nucleic Acid Amplification testing (CB-NAAT) using Xpert MTB/RiF assay technology. RESULTS The study period is from October 2013 to September 2014. A total of 907 patients with symptoms suggestive of pulmonary tuberculosis including both new cases and on treatment. Out of these patients 733 were reported MTB detected. Out of these 907 patients 29 were reported HIV positive and out of 733 patients 19(2.5%) were reported positive for (HIV +TUBERCULOSIS). Of these 19 cases 16(84.21%) cases were sensitive to rifampicin (RIF) and 3(15.78%) cases were showing resistance to rifampicin (RIF) Drug. CONCLUSION Co-existence of HIV and tuberculosis is high and there is high Prevalence of MDR tuberculosis in HIV patients.
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Affiliation(s)
- Deepak Arora
- Associate Professor, Department of Microbiology, GGSMC Faridkot, Punjab, India
| | - Neerja Jindal
- Professor & Head, Department of Microbiology, GGSMC Faridkot, Punjab, India
| | - Renu Bansal
- Professor, Department of Microbiology, GGSMC Faridkot Punjab, India
| | - Shilpa Arora
- Senior Resident, Department of Microbiology, GGSMC Faridkot Punjab, India
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Metcalfe JZ, Makumbirofa S, Makamure B, Mutetwa R, Peñaloza RA, Sandy C, Bara W, Mungofa S, Hopewell PC, Mason P. Suboptimal specificity of Xpert MTB/RIF among treatment-experienced patients. Eur Respir J 2015; 45:1504-6. [PMID: 25792637 DOI: 10.1183/09031936.00214114] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 01/05/2015] [Indexed: 11/05/2022]
Affiliation(s)
- John Z Metcalfe
- Curry International Tuberculosis Centre, Division of Pulmonary and Critical Care Medicine, San Francisco General Hospital, University of California, San Francisco, CA, USA
| | | | - Beauty Makamure
- Biomedical Research and Training Institute, Harare, Zimbabwe
| | - Reggie Mutetwa
- Biomedical Research and Training Institute, Harare, Zimbabwe
| | - Renée A Peñaloza
- Curry International Tuberculosis Centre, Division of Pulmonary and Critical Care Medicine, San Francisco General Hospital, University of California, San Francisco, CA, USA
| | - Charles Sandy
- National Tuberculosis Control Program, Harare, Zimbabwe
| | | | | | - Philip C Hopewell
- Curry International Tuberculosis Centre, Division of Pulmonary and Critical Care Medicine, San Francisco General Hospital, University of California, San Francisco, CA, USA
| | - Peter Mason
- Biomedical Research and Training Institute, Harare, Zimbabwe University of Zimbabwe College of Health Sciences, Harare, Zimbabwe
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Kelly JD, Grace Lin SY, Barry PM, Keh C, Higashi J, Metcalfe JZ. Xpert MTB/RIF false detection of rifampin-resistant tuberculosis from prior infection. Am J Respir Crit Care Med 2015; 190:1316-8. [PMID: 25436783 DOI: 10.1164/rccm.201408-1500le] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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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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Cox HS, Mbhele S, Mohess N, Whitelaw A, Muller O, Zemanay W, Little F, Azevedo V, Simpson J, Boehme CC, Nicol MP. Impact of Xpert MTB/RIF for TB diagnosis in a primary care clinic with high TB and HIV prevalence in South Africa: a pragmatic randomised trial. PLoS Med 2014; 11:e1001760. [PMID: 25423041 PMCID: PMC4244039 DOI: 10.1371/journal.pmed.1001760] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 10/13/2014] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Xpert MTB/RIF is approved for use in tuberculosis (TB) and rifampicin-resistance diagnosis. However, data are limited on the impact of Xpert under routine conditions in settings with high TB burden. METHODS AND FINDINGS A pragmatic prospective cluster-randomised trial of Xpert for all individuals with presumptive (symptomatic) TB compared to the routine diagnostic algorithm of sputum microscopy and limited use of culture was conducted in a large TB/HIV primary care clinic. The primary outcome was the proportion of bacteriologically confirmed TB cases not initiating TB treatment by 3 mo after presentation. Secondary outcomes included time to TB treatment and mortality. Unblinded randomisation occurred on a weekly basis. Xpert and smear microscopy were performed on site. Analysis was both by intention to treat (ITT) and per protocol. Between 7 September 2010 and 28 October 2011, 1,985 participants were assigned to the Xpert (n = 982) and routine (n = 1,003) diagnostic algorithms (ITT analysis); 882 received Xpert and 1,063 routine (per protocol analysis). 13% (32/257) of individuals with bacteriologically confirmed TB (smear, culture, or Xpert) did not initiate treatment by 3 mo after presentation in the Xpert arm, compared to 25% (41/167) in the routine arm (ITT analysis, risk ratio 0.51, 95% CI 0.33-0.77, p = 0.0052). The yield of bacteriologically confirmed TB cases among patients with presumptive TB was 17% (167/1,003) with routine diagnosis and 26% (257/982) with Xpert diagnosis (ITT analysis, risk ratio 1.57, 95% CI 1.32-1.87, p<0.001). This difference in diagnosis rates resulted in a higher rate of treatment initiation in the Xpert arm: 23% (229/1,003) and 28% (277/982) in the routine and Xpert arms, respectively (ITT analysis, risk ratio 1.24, 95% CI 1.06-1.44, p = 0.013). Time to treatment initiation was improved overall (ITT analysis, hazard ratio 0.76, 95% CI 0.63-0.92, p = 0.005) and among HIV-infected participants (ITT analysis, hazard ratio 0.67, 95% CI 0.53-0.85, p = 0.001). There was no difference in 6-mo mortality with Xpert versus routine diagnosis. Study limitations included incorrect intervention allocation for a high proportion of participants and that the study was conducted in a single clinic. CONCLUSIONS These data suggest that in this routine primary care setting, use of Xpert to diagnose TB increased the number of individuals with bacteriologically confirmed TB who were treated by 3 mo and reduced time to treatment initiation, particularly among HIV-infected participants. TRIAL REGISTRATION Pan African Clinical Trials Registry PACTR201010000255244. Please see later in the article for the Editors' Summary.
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Affiliation(s)
- Helen S. Cox
- Division of Medical Microbiology and Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- Médecins Sans Frontières, Khayelitsha, South Africa
- * E-mail:
| | - Slindile Mbhele
- Division of Medical Microbiology, University of Cape Town, Cape Town, South Africa
| | - Neisha Mohess
- Division of Medical Microbiology, University of Cape Town, Cape Town, South Africa
| | - Andrew Whitelaw
- Division of Medical Microbiology, University of Cape Town, Cape Town, South Africa
- National Health Laboratory Service, Johannesburg, South Africa
| | | | - Widaad Zemanay
- Division of Medical Microbiology, University of Cape Town, Cape Town, South Africa
| | - Francesca Little
- Department of Statistical Science, University of Cape Town, Cape Town, South Africa
| | | | - John Simpson
- National Health Laboratory Service, Johannesburg, South Africa
| | | | - Mark P. Nicol
- Division of Medical Microbiology and Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
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Steingart KR, Schiller I, Horne DJ, Pai M, Boehme CC, Dendukuri N. Xpert® MTB/RIF assay for pulmonary tuberculosis and rifampicin resistance in adults. Cochrane Database Syst Rev 2014; 2014:CD009593. [PMID: 24448973 PMCID: PMC4470349 DOI: 10.1002/14651858.cd009593.pub3] [Citation(s) in RCA: 427] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND Accurate, rapid detection of tuberculosis (TB) and TB drug resistance is critical for improving patient care and decreasing TB transmission. Xpert® MTB/RIF assay is an automated test that can detect both TB and rifampicin resistance, generally within two hours after starting the test, with minimal hands-on technical time. The World Health Organization (WHO) issued initial recommendations on Xpert® MTB/RIF in early 2011. A Cochrane Review on the diagnostic accuracy of Xpert® MTB/RIF for pulmonary TB and rifampicin resistance was published January 2013. We performed this updated Cochrane Review as part of a WHO process to develop updated guidelines on the use of the test. OBJECTIVES To assess the diagnostic accuracy of Xpert® MTB/RIF for pulmonary TB (TB detection), where Xpert® MTB/RIF was used as both an initial test replacing microscopy and an add-on test following a negative smear microscopy result.To assess the diagnostic accuracy of Xpert® MTB/RIF for rifampicin resistance detection, where Xpert® MTB/RIF was used as the initial test replacing culture-based drug susceptibility testing (DST).The populations of interest were adults presumed to have pulmonary, rifampicin-resistant or multidrug-resistant TB (MDR-TB), with or without HIV infection. The settings of interest were intermediate- and peripheral-level laboratories. The latter may be associated with primary health care facilities. SEARCH METHODS We searched for publications in any language up to 7 February 2013 in the following databases: Cochrane Infectious Diseases Group Specialized Register; MEDLINE; EMBASE; ISI Web of Knowledge; MEDION; LILACS; BIOSIS; and SCOPUS. We also searched the metaRegister of Controlled Trials (mRCT) and the search portal of the WHO International Clinical Trials Registry Platform to identify ongoing trials. SELECTION CRITERIA We included randomized controlled trials, cross-sectional studies, and cohort studies using respiratory specimens that allowed for extraction of data evaluating Xpert® MTB/RIF against the reference standard. We excluded gastric fluid specimens. The reference standard for TB was culture and for rifampicin resistance was phenotypic culture-based DST. DATA COLLECTION AND ANALYSIS For each study, two review authors independently extracted data using a standardized form. When possible, we extracted data for subgroups by smear and HIV status. We assessed the quality of studies using QUADAS-2 and carried out meta-analyses to estimate pooled sensitivity and specificity of Xpert® MTB/RIF separately for TB detection and rifampicin resistance detection. For TB detection, we performed the majority of analyses using a bivariate random-effects model and compared the sensitivity of Xpert® MTB/RIF and smear microscopy against culture as reference standard. For rifampicin resistance detection, we undertook univariate meta-analyses for sensitivity and specificity separately to include studies in which no rifampicin resistance was detected. MAIN RESULTS We included 27 unique studies (integrating nine new studies) involving 9557 participants. Sixteen studies (59%) were performed in low- or middle-income countries. For all QUADAS-2 domains, most studies were at low risk of bias and low concern regarding applicability.As an initial test replacing smear microscopy, Xpert® MTB/RIF pooled sensitivity was 89% [95% Credible Interval (CrI) 85% to 92%] and pooled specificity 99% (95% CrI 98% to 99%), (22 studies, 8998 participants: 2953 confirmed TB, 6045 non-TB).As an add-on test following a negative smear microscopy result, Xpert®MTB/RIF pooled sensitivity was 67% (95% CrI 60% to 74%) and pooled specificity 99% (95% CrI 98% to 99%; 21 studies, 6950 participants).For smear-positive, culture-positive TB, Xpert® MTB/RIF pooled sensitivity was 98% (95% CrI 97% to 99%; 21 studies, 1936 participants).For people with HIV infection, Xpert® MTB/RIF pooled sensitivity was 79% (95% CrI 70% to 86%; 7 studies, 1789 participants), and for people without HIV infection, it was 86% (95% CrI 76% to 92%; 7 studies, 1470 participants). Comparison with smear microscopy In comparison with smear microscopy, Xpert® MTB/RIF increased TB detection among culture-confirmed cases by 23% (95% CrI 15% to 32%; 21 studies, 8880 participants).For TB detection, if pooled sensitivity estimates for Xpert® MTB/RIF and smear microscopy are applied to a hypothetical cohort of 1000 patients where 10% of those with symptoms have TB, Xpert® MTB/RIF will diagnose 88 cases and miss 12 cases, whereas sputum microscopy will diagnose 65 cases and miss 35 cases. Rifampicin resistance For rifampicin resistance detection, Xpert® MTB/RIF pooled sensitivity was 95% (95% CrI 90% to 97%; 17 studies, 555 rifampicin resistance positives) and pooled specificity was 98% (95% CrI 97% to 99%; 24 studies, 2411 rifampicin resistance negatives). Among 180 specimens with nontuberculous mycobacteria (NTM), Xpert® MTB/RIF was positive in only one specimen that grew NTM (14 studies, 2626 participants).For rifampicin resistance detection, if the pooled accuracy estimates for Xpert® MTB/RIF are applied to a hypothetical cohort of 1000 individuals where 15% of those with symptoms are rifampicin resistant, Xpert® MTB/RIF would correctly identify 143 individuals as rifampicin resistant and miss eight cases, and correctly identify 833 individuals as rifampicin susceptible and misclassify 17 individuals as resistant. Where 5% of those with symptoms are rifampicin resistant, Xpert® MTB/RIF would correctly identify 48 individuals as rifampicin resistant and miss three cases and correctly identify 931 individuals as rifampicin susceptible and misclassify 19 individuals as resistant. AUTHORS' CONCLUSIONS In adults thought to have TB, with or without HIV infection, Xpert® MTB/RIF is sensitive and specific. Compared with smear microscopy, Xpert® MTB/RIF substantially increases TB detection among culture-confirmed cases. Xpert® MTB/RIF has higher sensitivity for TB detection in smear-positive than smear-negative patients. Nonetheless, this test may be valuable as an add-on test following smear microscopy in patients previously found to be smear-negative. For rifampicin resistance detection, Xpert® MTB/RIF provides accurate results and can allow rapid initiation of MDR-TB treatment, pending results from conventional culture and DST. The tests are expensive, so current research evaluating the use of Xpert® MTB/RIF in TB programmes in high TB burden settings will help evaluate how this investment may help start treatment promptly and improve outcomes.
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Affiliation(s)
- Karen R Steingart
- Liverpool School of Tropical MedicineCochrane Infectious Diseases GroupPembroke PlaceLiverpoolUK
| | - Ian Schiller
- McGill University Health CentreDepartment of Clinical EpidemiologyMcGill UniversityMontrealCanada
| | - David J Horne
- University of WashingtonDivision of Pulmonary and Critical Care MedicineSeattleUSA
| | - Madhukar Pai
- McGill UniversityDepartment of Epidemiology, Biostatistics and Occupational HealthPurvis Hall, Room 501020 Pine Avenue WestMontrealCanadaH3A 1A2
| | - Catharina C Boehme
- Foundation for Innovative New Diagnostics (FIND)16, Av de BudéGenevaSwitzerland
| | - Nandini Dendukuri
- McGill UniversityDepartment of Epidemiology, Biostatistics and Occupational HealthPurvis Hall, Room 501020 Pine Avenue WestMontrealCanadaH3A 1A2
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