Screening for HIV-associated tuberculosis and rifampicin resistance before antiretroviral therapy using the Xpert MTB/RIF assay: a prospective study

 

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dc.contributor.author Lawn, Stephen D en_ZA
dc.contributor.author Brooks, Sophie V en_ZA
dc.contributor.author Kranzer, Katharina en_ZA
dc.contributor.author Nicol, Mark P en_ZA
dc.contributor.author Whitelaw, Andrew en_ZA
dc.contributor.author Vogt, Monica en_ZA
dc.contributor.author Bekker, Linda-Gail en_ZA
dc.contributor.author Wood, Robin en_ZA
dc.date.accessioned 2016-01-11T06:50:53Z
dc.date.available 2016-01-11T06:50:53Z
dc.date.issued 2011 en_ZA
dc.identifier.citation Lawn, S. D., Brooks, S. V., Kranzer, K., Nicol, M. P., Whitelaw, A., Vogt, M., ... & Wood, R. (2011). Screening for HIV-associated tuberculosis and rifampicin resistance before antiretroviral therapy using the Xpert MTB/RIF assay: a prospective study. PLoS medicine, 8(7), 910. doi:10.1371/journal.pmed.1001067 en_ZA
dc.identifier.uri http://hdl.handle.net/11427/16236
dc.identifier.uri http://dx.doi.org/10.1371/journal.pmed.1001067
dc.description.abstract Background: The World Health Organization has endorsed the Xpert MTB/RIF assay for investigation of patients suspected of having tuberculosis (TB). However, its utility for routine TB screening and detection of rifampicin resistance among HIV-infected patients with advanced immunodeficiency enrolling in antiretroviral therapy (ART) services is unknown. Methods and Findings: Consecutive adult HIV-infected patients with no current TB diagnosis enrolling in an ART clinic in a South African township were recruited regardless of symptoms. They were clinically characterised and invited to provide two sputum samples at a single visit. The accuracy of the Xpert MTB/RIF assay for diagnosing TB and drug resistance was assessed in comparison with other tests, including fluorescence smear microscopy and automated liquid culture (gold standard) and drug susceptibility testing. Of 515 patients enrolled, 468 patients (median CD4 cell count, 171 cells/µl; interquartile range, 102–236) produced at least one sputum sample, yielding complete sets of results from 839 samples. Mycobacterium tuberculosis was cultured from 81 patients (TB prevalence, 17.3%). The overall sensitivity of the Xpert MTB/RIF assay for culture-positive TB was 73.3% (specificity, 99.2%) compared to 28.0% (specificity, 100%) using smear microscopy. All smear-positive, culture-positive disease was detected by Xpert MTB/RIF from a single sample (sensitivity, 100%), whereas the sensitivity for smear-negative, culture-positive TB was 43.4% from one sputum sample and 62.3% from two samples. Xpert correctly identified rifampicin resistance in all four cases of multidrug-resistant TB but incorrectly identified resistance in three other patients whose disease was confirmed to be drug sensitive by gene sequencing (specificity, 94.1%; positive predictive value, 57%). Conclusions: In this population of individuals at high risk of TB, intensive screening using the Xpert MTB/RIF assay increased case detection by 45% compared with smear microscopy, strongly supporting replacement of microscopy for this indication. However, despite the ability of the assay to rapidly detect rifampicin-resistant disease, the specificity for drug-resistant TB was sub-optimal. en_ZA
dc.language.iso eng en_ZA
dc.publisher Public Library of Science en_ZA
dc.rights This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. en_ZA
dc.rights.uri http://creativecommons.org/licenses/by/4.0 en_ZA
dc.source PLOS Medicince en_ZA
dc.source.uri http://journals.plos.org/plosmedicine en_ZA
dc.subject.other Tuberculosis en_ZA
dc.subject.other Mycobacterium tuberculosis en_ZA
dc.subject.other Tuberculosis diagnosis and management en_ZA
dc.subject.other Sputum en_ZA
dc.subject.other Multi-drug-resistant tuberculosis en_ZA
dc.subject.other Diagnostic medicine en_ZA
dc.subject.other Coughing en_ZA
dc.subject.other Extensively drug-resistant tuberculosis en_ZA
dc.title Screening for HIV-associated tuberculosis and rifampicin resistance before antiretroviral therapy using the Xpert MTB/RIF assay: a prospective study en_ZA
dc.type Journal Article en_ZA
dc.rights.holder © 2011 Lawn et al en_ZA
uct.type.publication Research en_ZA
uct.type.resource Article en_ZA
dc.publisher.institution University of Cape Town
dc.publisher.faculty Faculty of Health Sciences en_ZA
dc.publisher.department Desmond Tutu HIV Centre en_ZA
uct.type.filetype Text
uct.type.filetype Image


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This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Except where otherwise noted, this item's license is described as This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.