open access

Vol 88, No 3 (2020)
ORIGINAL PAPERS
Published online: 2020-07-18
Submitted: 2019-10-18
Accepted: 2020-03-18
Get Citation

Role of GeneXpert in the diagnosis of mycobacterium tuberculosis

Chinnu Sasikumar, Ketaki Utpat, Unnati Desai, Jyotsna Joshi
DOI: 10.5603/ARM.2020.0102
·
Pubmed: 32706101
·
Adv Respir Med 2020;88(3):183-188.

open access

Vol 88, No 3 (2020)
ORIGINAL PAPERS
Published online: 2020-07-18
Submitted: 2019-10-18
Accepted: 2020-03-18

Abstract

Introduction: GeneXpert (GX) is a novel, integrated, cartridge-based, nucleic acid amplification test with an established role for rapid diagnosis of Mycobacterium tuberculosis and detection of rifampicin resistance.
Aim: To evaluate the role of GX in pulmonary and extrapulmonary tuberculosis (TB) cases.
Material and methods: A prospective study was conducted in the pulmonary medicine department of a tertiary care hospital after the Ethics Comittee permission. Data of 257 presumptive TB patients was retrieved for GX, acid fast bacilli smear and cul-ture (AFB smear and culture) and drug susceptibility test (DST). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of GX in diagnosis and determination of rifampicin resistance in pulmonary and extrapulmonary TB cases were calculated and compared with culture and DST results.
Results: Our study included 132 pulmonary and 125 extrapulmonary cases. On the basis of clinicoradiological and microbiological correlation, diagnosis of TB was confirmed in 104 pulmonary and 103 extrapulmonary cases. Out of a total of 104 pulmonary TB cases, 73 were rifampicin-sensitive and 31 were rifampicin-resistant cases. 103 extrapulmonary TB patients included 66 rifampicin-sensitive and 37 rifampicin-resistant cases. The sensitivity, specificity, PPV, NPV of GX in diagnosis and detection of rifampicin resistance in pulmonary TB was 95%, 93%, 98%, 84% and 96%, 100%, 100%, 96%, respectively. The sensitivity, specificity, PPV, NPV of GX in diagnosis and detection of rifampicin resistance in extrapulmonary TB cases was 79%, 86%, 96%, 47% and 97%, 95%, 97%, 95%, respectively.
Conclusions: GX results are superior to smear microscopy and comparable to culture with shorter turnaround time.We recom-mend using it in routine TB diagnosis as this will expedite the management of patients with presumptive TB.

Abstract

Introduction: GeneXpert (GX) is a novel, integrated, cartridge-based, nucleic acid amplification test with an established role for rapid diagnosis of Mycobacterium tuberculosis and detection of rifampicin resistance.
Aim: To evaluate the role of GX in pulmonary and extrapulmonary tuberculosis (TB) cases.
Material and methods: A prospective study was conducted in the pulmonary medicine department of a tertiary care hospital after the Ethics Comittee permission. Data of 257 presumptive TB patients was retrieved for GX, acid fast bacilli smear and cul-ture (AFB smear and culture) and drug susceptibility test (DST). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of GX in diagnosis and determination of rifampicin resistance in pulmonary and extrapulmonary TB cases were calculated and compared with culture and DST results.
Results: Our study included 132 pulmonary and 125 extrapulmonary cases. On the basis of clinicoradiological and microbiological correlation, diagnosis of TB was confirmed in 104 pulmonary and 103 extrapulmonary cases. Out of a total of 104 pulmonary TB cases, 73 were rifampicin-sensitive and 31 were rifampicin-resistant cases. 103 extrapulmonary TB patients included 66 rifampicin-sensitive and 37 rifampicin-resistant cases. The sensitivity, specificity, PPV, NPV of GX in diagnosis and detection of rifampicin resistance in pulmonary TB was 95%, 93%, 98%, 84% and 96%, 100%, 100%, 96%, respectively. The sensitivity, specificity, PPV, NPV of GX in diagnosis and detection of rifampicin resistance in extrapulmonary TB cases was 79%, 86%, 96%, 47% and 97%, 95%, 97%, 95%, respectively.
Conclusions: GX results are superior to smear microscopy and comparable to culture with shorter turnaround time.We recom-mend using it in routine TB diagnosis as this will expedite the management of patients with presumptive TB.

Get Citation

Keywords

GeneXpert; presumptive TB cases; AFB culture

About this article
Title

Role of GeneXpert in the diagnosis of mycobacterium tuberculosis

Journal

Advances in Respiratory Medicine

Issue

Vol 88, No 3 (2020)

Pages

183-188

Published online

2020-07-18

DOI

10.5603/ARM.2020.0102

Pubmed

32706101

Bibliographic record

Adv Respir Med 2020;88(3):183-188.

Keywords

GeneXpert
presumptive TB cases
AFB culture

Authors

Chinnu Sasikumar
Ketaki Utpat
Unnati Desai
Jyotsna Joshi

References (22)
  1. Luetkemeyer A, Firnhaber C, Kendall M, et al. Evaluation of xpert MTB/RIF versus AFB smear and culture to identify pulmonary tuberculosis in patients with suspected tuberculosis from low and higher prevalence settings. Clinical Infectious Diseases. 2016; 62(9): 1081–1088.
  2. Walusimbi S, Bwanga F, Costa ADe, et al. Meta-analysis to compare the accuracy of GeneXpert, MODS and the WHO 2007 algorithm for diagnosis of smear-negative pulmonary tuberculosis. BMC Infectious Diseases. 2013; 13(1).
  3. Opota O, Senn L, Prod'hom G, et al. Added value of molecular assay Xpert MTB/RIF compared to sputum smear microscopy to assess the risk of tuberculosis transmission in a low-prevalence country. Clinical Microbiology and Infection. 2016; 22(7): 613–619.
  4. Lawn S, Nicol M. Xpert®MTB/RIF assay: development, evaluation and implementation of a new rapid molecular diagnostic for tuberculosis and rifampicin resistance. Future Microbiology. 2011; 6(9): 1067–1082.
  5. Chang K, Lu W, Wang J, et al. Rapid and effective diagnosis of tuberculosis and rifampicin resistance with Xpert MTB/RIF assay: A meta-analysis. Journal of Infection. 2012; 64(6): 580–588.
  6. Marlowe EM, Novak-Weekley SM, Cumpio J, et al. Evaluation of the cepheid xpert MTB/RIF assay for direct detection of mycobacterium tuberculosis complex in respiratory specimens. Journal of Clinical Microbiology. 2011; 49(4): 1621–1623.
  7. WHO, Rapid implementation of Xpert MTB/RIF Diagnostic test, WHO, 2011. Available at http://Whqubdoc.who.int?Publication/2011/9789241501569. [Last accessed on Nov 15th, 2017].
  8. Hillemann D, Rusch-Gerdes S, Boehme C, et al. Rapid molecular detection of extrapulmonary tuberculosis by the automated genexpert MTB/RIF system. Journal of Clinical Microbiology. 2011; 49(4): 1202–1205.
  9. Blakemore R, Story E, Helb D, et al. Evaluation of the analytical performance of the xpert MTB/RIF assay. Journal of Clinical Microbiology. 2010; 48(7): 2495–2501.
  10. Maynard-Smith L, Larke N, Peters J, et al. Diagnostic accuracy of the Xpert MTB/RIF assay for extrapulmonary and pulmonary tuberculosis when testing non-respiratory samples: a systematic review. BMC Infectious Diseases. 2014; 14(1).
  11. Sharma S, Kohli M, Yadav R, et al. Evaluating the diagnostic accuracy of Xpert MTB/RIF assay in pulmonary tuberculosis. PLOS ONE. 2015; 10(10): e0141011.
  12. Ramirez HLB, García-Clemente MM, Álvarez-Álvarez C, et al. Impact of the Xpert® MTB/RIF molecular test on the late diagnosis of pulmonary tuberculosis. The International Journal of Tuberculosis and Lung Disease. 2014; 18(4): 435–437.
  13. Boehme C, Nicol M, Nabeta P, et al. Feasibility, diagnostic accuracy, and effectiveness of decentralised use of the Xpert MTB/RIF test for diagnosis of tuberculosis and multidrug resistance: a multicentre implementation study. The Lancet. 2011; 377(9776): 1495–1505.
  14. Armand S, Vanhuls P, Delcroix G, et al. Comparison of the Xpert MTB/RIF Test with an IS6110-TaqMan Real-Time PCR Assay for Direct Detection of Mycobacterium tuberculosis in Respiratory and Nonrespiratory Specimens. Journal of Clinical Microbiology. 2011; 49(5): 1772–1776.
  15. Causse M, Ruiz P, Gutierrez-Aroca JB, et al. Comparison of two molecular methods for rapid diagnosis of extrapulmonary tuberculosis. Journal of Clinical Microbiology. 2011; 49(8): 3065–3067.
  16. Tortoli E, Russo C, Piersimoni C, et al. Clinical validation of Xpert MTB/RIF for the diagnosis of extrapulmonary tuberculosis. European Respiratory Journal. 2012; 40(2): 442–447.
  17. Denkinger CM, Schumacher SG, Boehme CC, et al. Xpert MTB/RIF assay for the diagnosis of extrapulmonary tuberculosis: a systematic review and meta-analysis. European Respiratory Journal. 2014; 44(2): 435–446.
  18. Penz E, Boffa J, Roberts DJ, et al. Diagnostic accuracy of the Xpert® MTB/RIF assay for extra-pulmonary tuberculosis: a meta-analysis. The International Journal of Tuberculosis and Lung Disease. 2015; 19(3): 278–284.
  19. Held M, Laubscher M, Zar HJ, et al. GeneXpert polymerase chain reaction for spinal tuberculosis. The Bone & Joint Journal. 2014; 96-B(10): 1366–1369.
  20. Jain A, Dixit P, Prasad R. Pre-XDR & XDR in MDR and ofloxacin and kanamycin resistance in non-MDR mycobacterium tuberculosis isolates. Tuberculosis. 2012; 92(5): 404–406.
  21. Kozińska M, Brzostek A, Krawiecka D, et al. MDR, pre-XDR and XDR drug-resistant tuberculosis in Poland in 2000–2009. Pneumonol Alergol Pol. 2011; 79: 278–87.
  22. Jain A, Mondal R, Prasad R, et al. Prevalence of multidrug resistant Mycobacterium tuberculosis in Lucknow, Uttar Pradesh. Indian J Med Res. 2008; 128: 300–306.

Important: This website uses cookies. More >>

The cookies allow us to identify your computer and find out details about your last visit. They remembering whether you've visited the site before, so that you remain logged in - or to help us work out how many new website visitors we get each month. Most internet browsers accept cookies automatically, but you can change the settings of your browser to erase cookies or prevent automatic acceptance if you prefer.

Czasopismo Pneumonologia i Alergologia Polska dostęne jest również w Ikamed - księgarnia medyczna

Wydawcą serwisu jest "Via Medica sp. z o.o." sp.k., ul. Świętokrzyska 73, 80–180 Gdańsk

tel.:+48 58 320 94 94, faks:+48 58 320 94 60, e-mail: viamedica@viamedica.pl