Xpert(®) MTB/RIF detection of rifampin resistance and time to treatment initiation in Harare, Zimbabwe.
Int J Tuberc Lung Dis
; 20(7): 882-9, 2016 07.
Article
em En
| MEDLINE
| ID: mdl-27287639
ABSTRACT
BACKGROUND:
Patients at elevated risk of drug-resistant tuberculosis (TB) are prioritized for Xpert(®) MTB/RIF testing; however, the clinical usefulness of the test in this population is understudied.DESIGN:
From November 2011 to June 2014, consecutive out-patients with a history of previous TB in high-density suburbs of Harare, Zimbabwe, were tested using Xpert, solid and liquid culture, and the microscopic observation drug susceptibility assay. Diagnostic accuracy for rifampin (RMP) resistance and time to initiation of second-line regimens were ascertained. The rpoB gene was sequenced in cases with culture-confirmed RMP resistance and genotypic susceptibility.RESULTS:
Among 352 retreatment patients, 71 (20%) were RMP-resistant, 98 (28%) RMP-susceptible, 64 (18%) culture-negative/Xpert-positive, and 119 (34%) culture-negative/Xpert-negative. Xpert had a sensitivity of 86% (95%CI 75-93) and a specificity of 98% (95%CI 92-100) for RMP-resistant TB. The positive predictive value of Xpert-determined RMP resistance for multidrug-resistant TB (MDR-TB) was 82% (95%CI 70-91). Of 71 (83%) participants, 59 initiated treatment with second-line drugs, with a median time to treatment initiation of 18 days (IQR 10-44).CONCLUSION:
The diagnostic accuracy of Xpert for RMP resistance is high, although the predictive value for MDR-TB was lower than anticipated. Xpert allows for faster initiation of second-line treatment than culture-based drug susceptibility testing under programmatic conditions.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Rifampina
/
Proteínas de Bactérias
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Tuberculose
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RNA Polimerases Dirigidas por DNA
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Análise Mutacional de DNA
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Técnicas de Diagnóstico Molecular
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Farmacorresistência Bacteriana
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Tempo para o Tratamento
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Mutação
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Mycobacterium tuberculosis
Tipo de estudo:
Diagnostic_studies
/
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
País/Região como assunto:
Africa
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article