Diagnostic performance of the Xpert MTB/RIF assay for tuberculous lymphadenitis on fine needle aspirates from Ethiopia
College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia; Institute of Medical Microbiology and Epidemiology of Infectious Diseases, University Hospital, University of Leipzig, Leipzig, Germany; Institute of Clinical Immunology, University Hospital, University of Leipzig, Leipzig, Germany; College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia; Institute of Medical Virology, University Hospital, University of Leipzig, Leipzig, Germany; Translational Centre for Regenerative Medicine (TRM)-Leipzig, University of Leipzig, Leipzig, Germany
The Xpert MTB/RIF (Xpert) test is a novel automated molecular diagnostic recently endorsed by the World Health Organization for rapid diagnosis of tuberculosis (TB). Nevertheless, performance related data from high TB prevalence regions to investigate clinically suspected TB lymphadenitis are limited. To evaluate the performance of Xpert test for direct detection of the Mycobacterium tuberculosis complex (MTBC) and rifampicin (RIF) resistance in lymph node aspirates, a cross-sectional study was conducted at four main hospitals in northern Ethiopia. Culture served as a reference standard for growth of MTBC and phenotypic and MTBDRplus drug susceptibility testing for detecting RIF resistance. Two-hundred-thirty-one fine needle aspirate (FNAs) specimens were processed simultaneously for smear, culture, and Xpert test. When compared to culture, the Xpert test correctly identified 29 out of 32 culture positive cases, 5 out of 11 contaminated cases, and 56 out of 188 culture negative cases. The overall sensitivity of the test was 93.5% [95% CI, 78.3-98.9%] and specificity 69.2% [95% CI, 66.4-70.0%]. The Xpert test identified the rpoB mutations associated with RIF resistance concordant with GenoType MTBDRplus and phenotypic drug susceptibility testing. In conclusion, the Xpert assay was found to perform well in detecting MTBC and RIF resistance in TB lymphadenitis patients. Furthermore, the test is simple and suitable to use in remote and rural areas for the diagnosis of TB lymphadenitis directly from FNAs in Ethiopia where TB/MDR-TB is rampant. © 2014 Elsevier Ltd. All rights reserved.
rifampicin; RNA polymerase beta subunit; bacterial protein; diagnostic kit; rifampicin; rpoB protein, Mycobacterium tuberculosis; tuberculostatic agent; adolescent; adolescent; antibiotic resistance; antibiotic resistance; antibiotic sensitivity; antibiotic sensitivity; Article; Article; bacterial growth; bacterial growth; bacterium culture; bacterium culture; bacterium detection; bacterium detection; controlled study; controlled study; cross-sectional study; cross-sectional study; diagnostic accuracy; diagnostic accuracy; diagnostic test accuracy study; diagnostic test accuracy study; diagnostic value; diagnostic value; Ethiopia; Ethiopia; female; female; fine needle aspiration biopsy; fine needle aspiration biopsy; gene mutation; gene mutation; human; human; lymph node biopsy; lymph node biopsy; major clinical study; major clinical study; male; male; molecular diagnosis; molecular diagnosis; multicenter study; multicenter study; Mycobacterium tuberculosis; Mycobacterium tuberculosis; Mycobacterium tuberculosis test kit; Mycobacterium tuberculosis test kit; nonhuman; nonhuman; phenotype; phenotype; sensitivity and specificity; sensitivity and specificity; tuberculous lymphadenitis; tuberculous lymphadenitis; antibiotic resistance; cell culture; clinical trial; comparative study; diagnostic kit; drug effects; evaluation study; fine needle aspiration biopsy; genetics; genotype; isolation and purification; lymph node; microbial sensitivity test; microbiology; mutation; Mycobacterium tuberculosis; nucleotide sequence; predictive value; prevalence; procedures; real time polymerase chain reaction; Tuberculosis, Lymph Node; Tuberculosis, Multidrug-Resistant; Adolescent; Antitubercular Agents; Bacterial Proteins; Biopsy, Fine-Needle; Cells, Cultured; Cross-Sectional Studies; DNA Mutational Analysis; Drug Resistance, Bacterial; Ethiopia; Female; Genotype; Humans; Lymph Nodes; Male; Microbial Sensitivity Tests; Mutation; Mycobacterium tuberculosis; Phenotype; Predictive Value of Tests; Prevalence; Reagent Kits, Diagnostic; Real-Time Polymerase Chain Reaction; Rifampin; Tuberculosis, Lymph Node; Tuberculosis, Multidrug-Resistant
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