Increased detection of smear-negative pulmonary tuberculosis by GeneXpert MTB/RIF® assay after bleach concentration

Tadesse, Mulualem; Aragaw, Dossegnaw; Rigouts, Leen; Abebe, Gemeda

doi:10.1016/j.ijmyco.2016.03.005

Cited by 24 publications

(30 citation statements)

References 18 publications

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“…However, the high proportion (49.3%) of smear-negative Xpert-positive results could be partially ascribed to performing smear microscopy directly on unprocessed sample, differently from Xpert that was carried out on concentrated sample. In line with this evidence, recently, Tadesse and colleagues demonstrated that bleach concentration and pelleting of smear-negative samples increase Xpert sensitivity from 63.2% to 73.8% [34]. …”

Section: Discussionmentioning

confidence: 75%

Diagnosis of smear-negative tuberculosis is greatly improved by Xpert MTB/RIF

et al. 2017

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BackgroundDiagnosis of pulmonary (PTB) and extra-pulmonary tuberculosis (EPTB) in smear-negative patients can be difficult. We assessed retrospectively the performance of Xpert MTB/RIF system (Xpert, Cepheid) in diagnosing smear-negative tuberculosis (TB), which represents the most common form of TB in a low incidence setting.MethodsPerformance of Xpert was compared to acid-fast microscopic examination using Ziehl-Neelsen (ZN) stain in patients with culture-confirmed TB.Results386 Mycobacterium tuberculosis (MTB) culture-positive samples were detected out of 5170 specimens tested with smear microscopy, Xpert and culture: 323 were both culture- and Xpert-positive, and 63 culture-positive only. Of these, 234 (60.6%) were smear-negative. In addition Xpert detected 40 probable TB cases, based on clinical findings, which were culture-negative.Compared to culture, Xpert showed an overall sensitivity of 83.7% and a specificity of 99.1%; sensitivity was higher for respiratory samples (86.5%) than for non-respiratory samples (76.8%). Xpert sensitivity for smear-negative culture-confirmed TB was 73.1% and was not influenced by TB localization. As sensitivity of microscopy alone was poor (39.4%), Xpert improved both diagnosis of pulmonary TB (Δ = 36.5%) and extra-pulmonary TB (Δ = 63.4%).ConclusionsXpert MTB/RIF is a sensitive method for rapid diagnosis of TB compared to the conventional ZN staining. Xpert can serve as a sensitive and time-saving diagnostic method for microbiological diagnosis of smear-negative TB in countries with a low TB prevalence.

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Section: Discussionmentioning

confidence: 75%

Diagnosis of smear-negative tuberculosis is greatly improved by Xpert MTB/RIF

et al. 2017

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“…In the Patient Selection domain, we considered 55 studies (64%) to have low risk of bias because the study enrolled a consecutive or random sample of eligible participants and avoided inappropriate exclusions. We considered 16 studies (19%) to have high risk of bias because the study did not avoid inappropriate exclusions: 13 studies enrolled participants whose sputum specimens were primarily or exclusively smear‐positive or smear‐negative ( Barnard 2015 ; Friedrich 2011 ; Jo 2016 ; Lee 2013 ; Le Palud 2014 ; Meyer 2017 ; Mok 2016 ; Moure 2011 ; Tadesse 2016 ; Theron 2013 ; Van Rie 2013 ; Walusimbi 2013a ; Williamson 2012 ) and three studies exclusively enrolled participants who had previously received tuberculosis treatment ( Meawed 2016 ; Metcalfe 2015 ; Pimkina 2015 ). In addition, we considered 15 studies (17%) to have unclear risk of bias because the manner of participant selection was not stated ( Atwebembeire 2016 ; Barmankulova 2015 ; Bates 2013a ; Boum 2016 ; Chen 2017 ; Huang 2015 ; Kim CH 2015 ; Luetkemeyer 2016 ; Mbelele 2017 ; Moussa 2016 ; Mutingwende 2015 ; Nosova 2013a ; Reechaipichitkul 2017 ; Shao 2017 ; Shenai 2016 ).…”

Section: Resultsmentioning

confidence: 99%

“…In the Patient Selection domain, we considered 36 studies (63%) to have low risk of bias because the study enrolled a consecutive or random sample of eligible participants and avoided inappropriate exclusions. We considered 10 studies (18% ) to have high risk of bias because the study did not avoid inappropriate exclusions and instead enrolled participants preselected on the basis of their sputum specimens being either smear‐positive or smear‐negative or the study exclusively enrolled retreatment participants ( Ali 2017 ; Friedrich 2011 ; Lee 2013 ; Le Palud 2014 ; Makamure 2017 ; N'Guessan 2016 ; Tadesse 2016 ; Theron 2013 ; Van Rie 2013 ; Williamson 2012 ). We considered 11 studies (19%) to have unclear risk of bias because the manner of participant selection was not reported ( Barmankulova 2015 ; Barnard 2015 ; Bates 2013a ; Huang 2015 ; Kim CH 2015 ; Luetkemeyer 2016 ; Meawed 2016 ; Moussa 2016 ; Nosova 2013a ; Pimkina 2015 ; Singh 2016 ).…”

Section: Resultsmentioning

confidence: 99%

“…We excluded 16 studies, i.e. 13 studies that preselected participants on the basis of a prior smear microscopy result (participants whose sputum specimens were primarily or exclusively smear‐positive or smear‐negative) ( Barnard 2015 ; Friedrich 2011 ; Jo 2016 ; Lee 2013 ; Le Palud 2014 ; Meyer 2017 ; Mok 2016 ; Moure 2011 ; Tadesse 2016 ; Theron 2013 ; Van Rie 2013 ; Walusimbi 2013a ; Williamson 2012 ) and three studies that preselected participants who had previously received tuberculosis treatment ( Meawed 2016 ; Metcalfe 2015 ; Pimkina 2015 ) ( Figure 10 ).

Figure 10 Forest plots of Xpert sensitivity and specificity for detection of pulmonary tuberculosis in studies with unselected participants.…”

Section: Resultsmentioning

confidence: 99%

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Xpert MTB/RIF and Xpert MTB/RIF Ultra for pulmonary tuberculosis and rifampicin resistance in adults

Horne

Kohli

Zifodya

et al. 2019

Cochrane Database of Systematic Reviews

182

157

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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 ( ). 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 MTBDR plus 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 detection Of 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 ...

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“…Ethiopia remains a high burden country for tuberculosis and most cases are smear negative (58.9%) (11). Gene Xpert has increased the diagnostic yield in smear negative patients (12), however, a signi cant number of patients still undergo tuberculosis treatment based on clinical observation alone. In our patient population, 7 of 18 patients suspect of TB but who were originally smear negative had tuberculosis con rmed with BAL.…”

Section: Discussionmentioning

confidence: 99%

Utility of Fiberoptic Bronchoscopy at Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia

Ahmed¹,

Parekh

Binegdie

et al. 2019

Preprint

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Objective Fiberoptic bronchoscopy (FOB) is a widely used tool in the diagnosis and treatment of pulmonary diseases. However, little is known regarding the indications and diagnostic yield of FOB in Ethiopia. The objective of this study was to determine the indications and diagnostic yield of FOB at Tikur Anbessa Specialized Hospital (TASH), the largest public health hospital in Ethiopia. Results In this retrospective chart review, all patients undergoing FOB between January and December 2013 in the bronchoscopy suite were studied. Data included: patient demographics, smoking, HIV status, procedure indications, and microbiologic, cytological and pathologic results. During the study period, 141 patients underwent FOB. The mean age was 42 years; 90(63%) were men. Among those whose smoking status was known, 15% were current or former smokers. The most common indications for FOB were: lung mass (presumed malignancy) 54% (76), tuberculosis 13% (18), and pleural effusion with possible underlying lung cancer 9%(13). 65 patients had endobronchial and/or transbronchial biopsies; 48% (31/65) were diagnostic and of these 68% (21/31) had malignancies. 57 patients had BAL performed; 33% (19/57) were diagnostic and of these 37% (7/19) had tuberculosis. We found that bronchoscopy was a safe and effective tool for diagnosing lung disease in Ethiopia.

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Increased detection of smear-negative pulmonary tuberculosis by GeneXpert MTB/RIF® assay after bleach concentration

Cited by 24 publications

References 18 publications

Diagnosis of smear-negative tuberculosis is greatly improved by Xpert MTB/RIF

Diagnosis of smear-negative tuberculosis is greatly improved by Xpert MTB/RIF

Xpert MTB/RIF and Xpert MTB/RIF Ultra for pulmonary tuberculosis and rifampicin resistance in adults

Utility of Fiberoptic Bronchoscopy at Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia

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