Intra-gastric string test: an effective tool for diagnosing tuberculosis in adults unable to produce sputum

Atwine, Daniel; Nansumba, Margaret; Orikiriza, Patrick; Riera, Manel; Nackers, Fabienne; Kamara, Nicholas; Beaudrap, Pierre De; Boum, Yap; Bonnet, Maryline

doi:10.5588/ijtld.14.0810

Cited by 10 publications

(9 citation statements)

References 23 publications

(25 reference statements)

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“…We have not described the clinical characteristics of the patients in this laboratorybased study, as these were published elsewhere. 8,9 CONCLUSION Xpert should be used with caution on stored frozen sediments, given its varying performance depending on the type of patient (children vs. adults) and the type of specimen (ST vs. IS). In our study, we found that Xpert performed better on frozen adult ST sediments.…”

Section: Discussionmentioning

confidence: 99%

“…8,9 Specimen collection and laboratory procedures As part of the main study, we collected fresh specimens using SI with 5% hypertonic saline for a maximum of 20 min and the ST with an intragastric downtime of 2 h. 8,9 The IS and ST specimens were then decontaminated using 0.5% N-acetyl-L-cysteine-1.5% sodium hydroxide, followed by neutralisation with phosphate buffer solution, centrifugation and inoculation into BACTECe MGITe (Mycobacterium Growth Indicator Tube; BD, Sparks, MD, USA) in Löwenstein-Jensen (LJ) medium. 8,9 The remaining sediment was frozen at À208C for 6-36 months and used in this substudy to evaluate Xpert performance on frozen samples in comparison with the original results on fresh samples.…”

Section: Study Settingmentioning

confidence: 99%

“…7 TB detection yield was recently found to be comparable between ST and SI using microscopy and culture in patients presumed to have TB but unable to produce good-quality sputum. 8,9 The traditional gold standard for TB diagnosis in samples from all body sites is standard microbiological culture, which is cumbersome in low-resource settings due to the long culture time, expensive reagents and difficult patient follow-up. To circumvent these challenges, alternative tools to diagnose TB have recently been developed, including the Xpert w MTB/RIF test (Cepheid, Sunnyvale, CA, USA).…”

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confidence: 99%

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Xpert® MTB/RIF for detection of Mycobacterium tuberculosis from frozen string and induced sputum sediments

Atwebembeire

Orikiriza

Bonnet³

et al. 2016

int j tuberc lung dis

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Section: Discussionmentioning

confidence: 99%

Section: Study Settingmentioning

confidence: 99%

mentioning

confidence: 99%

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Xpert® MTB/RIF for detection of Mycobacterium tuberculosis from frozen string and induced sputum sediments

Atwebembeire

Orikiriza

Bonnet³

et al. 2016

int j tuberc lung dis

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“…Because the string could also absorb sputum that has been swallowed, it has been proposed as a technique for obtaining lower respiratory specimens for tuberculosis testing in children. Several studies in adults have found that string samples have a diagnostic yield that is roughly similar to induced sputum [ 13 – 15 ]. The handful of studies in children have reported that > 80% could swallow the capsule and complete the test [ 4 , 16 , 17 ]; though this rate may vary by the child’s age, with the youngest children least able to swallow the capsule [ 13 ].…”

Section: Introductionmentioning

confidence: 99%

“…Several studies in adults have found that string samples have a diagnostic yield that is roughly similar to induced sputum [ 13 – 15 ]. The handful of studies in children have reported that > 80% could swallow the capsule and complete the test [ 4 , 16 , 17 ]; though this rate may vary by the child’s age, with the youngest children least able to swallow the capsule [ 13 ]. Among children who complete the test, diagnostic yield is comparable to sputum or gastric aspirate [ 13 , 18 ].…”

Section: Introductionmentioning

confidence: 99%

Feasibility of the string test for tuberculosis diagnosis in children between 4 and 14 years old

et al. 2018

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BackgroundThe enteric string test can be used to obtain a specimen for microbiological confirmation of tuberculosis in children, but it is not widely used for this. The aim of this analysis to evaluate this approach in children with tuberculosis symptoms.MethodsWe conducted a cross-sectional study to assess children’s ability to complete the test (feasibility), and self-reported pain (tolerability). We examined caregivers’ and children’s willingness to repeat the procedure (acceptability) and described the diagnostic yield of cultures for diagnostic tools. We stratified estimates by age and compared metrics to those derived for gastric aspirate (GA).ResultsAmong 148 children who attempted the string test, 34% successfully swallowed the capsule. Feasibility was higher among children aged 11–14 than in children 4–10 years (83% vs 22% respectively, p < 0.0001). The string test was better tolerated than GA in both age groups; however, guardians and older children reported higher rates of willingness to repeat GA than the string test (86% vs. 58% in children; 100% vs. 83% in guardians). In 9 children with a positive sputum culture, 6 had a positive string culture. The one children with a positive gastric aspirate culture also had a positive string culture.ConclusionAlthough the string test was generally tolerable and accepted by children and caregivers; feasibility in young children was low. Reducing the capsule size may improve test success rates in younger children.

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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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Intra-gastric string test: an effective tool for diagnosing tuberculosis in adults unable to produce sputum

Cited by 10 publications

References 23 publications

Xpert<SUP>®</SUP> MTB/RIF for detection of <I>Mycobacterium tuberculosis</I> from frozen string and induced sputum sediments

Xpert<SUP>®</SUP> MTB/RIF for detection of <I>Mycobacterium tuberculosis</I> from frozen string and induced sputum sediments

Feasibility of the string test for tuberculosis diagnosis in children between 4 and 14 years old

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

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