Evaluation of GeneXpert MTB for detection of Mycobacterium tuberculosis in Fayoum Governorate

Abstract

Background Despite being one of the most ancient diseases, tuberculosis (TB) is still a major health problem globally. It is one of the most important causes of death worldwide. GeneXpert MTB/RIF assay is a fast nucleic acid amplification test used for detection of TB as well as identification of rifampicin resistance. Design This was a cross-sectional study. Setting The study was conducted at Fayoum Chest Hospital, Egypt, between December 2017 and December 2018. Objectives To evaluate GeneXpert MTB/RIF in detection of Mycobacterium tuberculosis in Fayoum Chest Hospital. Patients and methods One hundred participants were enrolled in this study with clinical or radiological susceptibility of pulmonary or extrapulmonary TB. All patients underwent the following: full history taking, clinical examination, plain chest radiography, examination of specimen by Ziehl–Neelsen stain, cultivation on Lowenstein–Jensen media, and processed in GeneXpert MTB/RIF. Results GeneXpert assay is a good, fast, noninvasive, and accurate diagnostic tool for detection of M. tuberculosis, showing sensitivity of 100.0%, specificity of 85.0%, positive predictive value of 96.4%, negative predictive value of 100%, and accuracy of 97%. On the contrary, Ziehl–Neelsen had sensitivity of 83.75%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 60.61%. Conclusion GeneXpert is a fast, accurate, and promising technique with good sensitivity and specificity, but it cannot be used alone as a diagnostic tool for TB.

Keywords

• extrapulmonary tuberculosis
• fayoum governorate
• genexpert mtb/rif
• pulmonary tuberculosis