Evaluation of GeneXpert, as a New Diagnostic Tool for Detection of Pulmonary Tuberculosis

Abstract

Infection with Mycobacterium tuberculosis has plagued humanity since antiquity. Globally in 2014, there were an estimated 9.6 million incident cases of TB: 5.4 million among men, 3.2 million among women and 1.0 million among children. Tuberculosis remains a public health problem in Egypt. Although Egypt is in the era of epidemiological transition from communicable to non- communicable diseases like many other countries, TB, still, must be addressed and handled as a health problem affecting large sectors in the society, especially the poor and the vulnerable. No single diagnostic test currently satisfies all the demands of “rapid”, “affordable”, and “easy”. Mycobacterial culture is the gold standard for detecting M. tuberculosis, but it is time-consuming and so imperfect. It is generally able to detect 100 bacilli/ml of sputum, but results take weeks and approximately 20 percent of clinically suspected pulmonary M. tuberculosis infections remain culture-negative. Smear microscopy is highly specific in settings where tuberculosis is more prevalent. Direct examination of specimens by means of an acid-fast stain such as Ziehl-Neelsen or Kinyoun provides supportive evidence of mycobacterial disease weeks before the culture and identification may be available. The Xpert MTB/RIF assay is a new test that is revolutionizing tuberculosis (TB) control by contributing to the rapid diagnosis of TB disease and drug resistance. The test simultaneously detects Mycobacterium tuberculosis complex (MTBC) and resistance to rifampin (RIF) in less than