The Xpert® MTB/RIF assay in routine diagnosis of pulmonary tuberculosis: A multicentre study in Lithuania.

Abstract

INTRODUCTION:

Drug-resistant tuberculosis (TB) is an important public health problem in Lithuania with MDR rates in new cases reaching 11% in 2012. Currently available diagnostic tools are not fully adequate for an accurate and rapid result for diagnosis of TB and MDR-TB.

OBJECTIVES:

To evaluate the performance of Xpert(®) MTB/RIF assay for an early diagnosis of TB and detection of rifampicin (RIF) resistance in routine settings in Lithuania.

METHODS:

A total of 833 individual respiratory samples obtained from patients previously treated for TB and MDR-TB contacts were tested using the Xpert MTB/RIF assay. Performance characteristics of the assay for TB and RIF resistance detection were calculated using culture and phenotypical DST results as a gold standard.

RESULTS:

The overall sensitivity and specificity of the Xpert MTB/RIF assay for TB detection were 93.7% and 91.7%, respectively with the sensitivity for smear-negative specimens reaching 82.5%. Resistance to RIF was detected in 81 (20.7%) primary specimens with no false negative results; there were 4/225 (1.8%) false-positives among strains sensitive to rifampicin. Overall sensitivity and specificity of the molecular assay for detection of RIF resistance calculated against phenotypic DST results were 100% and 98.2%, respectively.

CONCLUSIONS:

Our results demonstrate very good performance of the Xpert MTB/RIF assay for the detection of TB and RIF resistance on primary respiratory specimens. It provides strong evidence that implementation of the assay for routine laboratory diagnosis in high drug-resistance settings may improve and facilitate TB diagnosis.

• Authors: Edita Pimkina, Rolandas Zablockis, Vladyslav Nikolayevskyy, Edvardas Danila, Edita Davidaviciene
• Journal: Respiratory medicine (Respir Med) Vol. 109 Issue 11 Pg. 1484-9 (Nov 2015) ISSN: 1532-3064 [Electronic] England
• PMID: 26403251 (Publication Type: Evaluation Study, Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 Elsevier Ltd. All rights reserved.

Chemical References

• Antibiotics, Antitubercular
• Rifampin

Topics

• Adult
• Antibiotics, Antitubercular (pharmacology, therapeutic use)
• Early Diagnosis
• Female
• Humans
• Male
• Microbial Sensitivity Tests (methods)
• Middle Aged
• Mycobacterium tuberculosis (drug effects, genetics, isolation & purification)
• Point-of-Care Systems
• Polymerase Chain Reaction (methods)
• Retrospective Studies
• Rifampin (pharmacology, therapeutic use)
• Sputum (microbiology)
• Tuberculosis, Multidrug-Resistant (diagnosis, drug therapy)
• Tuberculosis, Pulmonary (diagnosis, drug therapy)