TB Research

Evaluation of GeneXpert MTB/RIF Assay for Detection of Pulmonary Tuberculosis on Sputum Samples

Yasemin A, Ahmad S, Afzal S, Ullah A, Sheed A

Journal of the College of Physicians and Surgeons--Pakistan : JCPSP · 2019-01

Abstract

Objective To analyse the diagnostic performance of MTB/RIF assay for the diagnosis of pulmonary tuberculosis and detection of rifampicin resistance using sputum samples. Study design Observational cross-sectional study. Place and duration of study Provincial TB Reference Laboratory (PTRL), Hayatabad Medical Complex, Peshawar, Pakistan, from January to October 2015. Methodology A total of 268 participants were consecutively enrolled in the study after meeting the inclusion criteria. Their sputum samples were collected and processed by N-acetyl-L-cysteine-sodium hydroxide (NALC-NaOH) method and GeneXpert MTB/RIF assay. Results This study determined the overall sensitivity and specificity of MTB/RIF assay, it was 92.4% (86/93) and 97.1% (138/142), respectively. The sensitivity was 98.4% (60/61) in culture proven smear positive samples, whilst sensitivity in culture proven smear negative samples was 93.7% (30/32), using culture as reference standard. Conclusion GeneXpert MTB/RIF assay could greatly improve early diagnosis of PTB in smear negative cases as well as multidrug resistant tuberculosis.

MeSH terms

  • Sputum
  • Humans
  • Mycobacterium tuberculosis
  • Tuberculosis, Multidrug-Resistant
  • Tuberculosis, Pulmonary
  • Rifampin
  • Antibiotics, Antitubercular
  • Molecular Diagnostic Techniques
  • Bacteriological Techniques
  • Sensitivity and Specificity
  • Cross-Sectional Studies
  • Polymerase Chain Reaction
  • Sequence Analysis, DNA
  • Female
  • Male