Pediatric Infectious Disease

Register      Login

VOLUME 1 , ISSUE 4 ( October-December, 2019 ) > List of Articles

Original Article

Utility of GeneXpert for Detection of Mycobacterium tuberculosis and Rifampicin Resistance in Pediatric Tuberculosis

Ashwani K Sood, Mohit Bajaj, Ravinder Kumar, Anil Kanga

Keywords : Cartridge-based nucleic acid amplification test, Childhood, GeneXpert, MGIT culture, Tuberculosis

Citation Information : Sood AK, Bajaj M, Kumar R, Kanga A. Utility of GeneXpert for Detection of Mycobacterium tuberculosis and Rifampicin Resistance in Pediatric Tuberculosis. Pediatr Inf Dis 2019; 1 (4):137-141.

DOI: 10.5005/jp-journals-10081-1229

License: CC BY-NC 4.0

Published Online: 23-07-2020

Copyright Statement:  Copyright © 2019; Jaypee Brothers Medical Publishers (P) Ltd.


Abstract

Background: Childhood tuberculosis (TB) is an important cause of morbidity and mortality in the developing countries. In 2014, the World Health Organization (WHO) recommended the use of GeneXpert as the initial diagnostic test for detecting all cases of pediatric TB. Only limited data are available on the utility of GeneXpert in the diagnosis of pediatric TB. The present study was done to evaluate the efficacy of GeneXpert as diagnostic tool for pediatric TB detection. Objectives: To understand the utility of GeneXpert for detecting Mycobacterium tuberculosis and rifampicin resistance in pediatric TB. Materials and methods: This was a prospective cross-sectional study done in a tertiary care teaching hospital over a period of 1 year. After obtaining consent, sputum/induced sputum (IS)/gastric aspirate (GA)/fine needle aspiration cytology (FNAC)/cerebrospinal fluid (CSF)/pleural tap samples were obtained and subjected for cartridge-based nucleic acid amplification test (CBNAAT) and Mycobacterium growth indicator tube (MGIT) culture, respectively. Results: Based on the inclusion criteria, 128 children with presumptive TB were enrolled; of which 76 children were diagnosed with TB [30 with pulmonary TB (PTB) and 46 with extrapulmonary tuberculosis (EPTB)]. In EPTB, lymph node TB was most commonly seen in 37.0% subjects. In pulmonary TB, GeneXpert sensitivity and specificity were 85.71% (95% confidence interval, CI 62.64–96.23%) and 77.7% (95% CI 40.19–96.05%), respectively. Observed positive predictive value (PPV) and negative predictive value (NPV) of GeneXpert were 90% (95% CI 66.87–98.24%) and 70% (95% CI 35.36–91.90%), respectively. Sensitivity and specificity in EPTB was observed to be 50% (95% CI 28.80–71.19%) and 83.33% (95% CI 61.81–94.52%) with PPV of 73.33% (44.82–91.08%) and NPV of 64.51% (45.38–80.17%), with an overall sensitivity and specificity of GeneXpert of 67.39 and 92.68%, respectively, and PPV and NPV of 83.78 and 83.51, respectively. All the recruited subjects were found to be rifampicin sensitive. Conclusion: GeneXpert is a very useful test with a high sensitivity and specificity for diagnosing pediatric TB and for detection of rifampicin resistance in a short period of time.


PDF Share
  1. Sager P, Schalimtzek M, Moller-Christensen V. A case of spondylitis tuberculosa in the danish neolithic age. Dan Med Bull 1972;19(5): 176–180.
  2. Global Tuberculosis Report 2016, WHO Report 2014. http://www.who.int/tb/publications/global_report/2017/en/index.html. accessed 31 October, 2017).
  3. Udani PM. Tuberculosis in general. In: Parthasarathy A. Text book of Paediatrics. 1st ed., New Delhi: Jay Pee Brothers Publishers; 1991. pp. 995–1236.; National Guidelines on diagnosis and treatment of Pediatric Tuberculosis 2017, https://tbcindia.gov.in/showfile.php?lid=2904 page 8–15.
  4. World Health Organization. Automated real-time nucleic acid amplification technology for rapid and simultaneous detection of tuberculosis and rifampicin resistance: Xpert MTB/RIF assay for the diagnosis of pulmonary and extrapulmonary TB in adults and children: policy update. Geneva, Switzerland: WHO; 2013.
  5. Kumar A, Gupta D, Nagaraja SB, et al. Updated national guidelines for pediatric TB in India, 2012. Indian Pediatr 2013;50:301–306.
  6. Global laboratory initiative advancing TB diagnosis mycobacteriology laboratory manual April 2014. http://www.who.int/tb/laboratory/mycobacteriology-laboratory-manual.pdf. Accessed August 2014. pp. 33–46.
  7. Garg P. Childhood tuberculosis in a community hospital from a region of high environmental exposure in north India. J Clin Diagn Res 2008:2:634–638.
  8. Franco R, Santana M. Clinical and radiological analysis of children and adolescents with tuberculosis in Bahia, Brazil. Braz J Infect Dis 2003;7:73–81.
  9. de Pontual L, Balu L, Ovetchkine P, et al. Tuberculosis in adolescents: a French retrospective study of 52 cases. Pediatr Infect Dis J 2006;25:930–932.
  10. Van Zyl-Smit RN, Binder A, Meldau R, et al. Comparison of quantitative techniques including Xpert MTB/RIF to evaluate mycobacterial burden. PLoS ONE 2011;6(12):e28815. DOI: 10.1371/journal. pone.0028815.
  11. World Health Organization (WHO). Automated real-time nucleic acid amplification technology for rapid and simultaneous detection of tuberculosis and rifampicin resistance: Xpert MTB/RIF assay for the diagnosis of pulmonary and extra pulmonary TB in adults and children. Geneva: World Health Organization; 2011. Available from: http://apps.who.int/iris/bitstream/10665/112472/1/9789241506335_eng.pdf?ua=1.
  12. Rachow A, Clowes P, Saathoff E, et al. Increased and expedited case detection by Xpert MTB/RIF assay in childhood tuberculosis: a prospective cohort study. Clin Infect Dis 2012;54; 1388–1396.
  13. Sekadde MP, Wobudeya E, Joloba ML, et al. Evaluation of the Xpert MTB/RIF test for the diagnosis of childhood pulmonary tuberculosis in Uganda: a cross-sectional diagnostic study. BMC Infect Dis 2013;13;133.
  14. Marais BJ, Gie RP, Hesseling AC, et al. A refined symptom based approach to diagnose pulmonary tuberculosis in children. Pediatrics 2006;118:e1350–e1359.
  15. Helb D, Jones M, Story E, et al. Rapid detection of Mycobacterium tuberculosis and rifampin resistance by use of on-demand, near-patient technology. J Clin Microbiol 2010;1:229–232.
PDF Share
PDF Share

© Jaypee Brothers Medical Publishers (P) LTD.