Initial experience with GeneXpert MTB/RIF assay in the Arkansas Tuberculosis Control Program
Naveen Patil, Hamida Saba, Asween Marco, Rohan Samant, Leonard Mukasa
Abstract
Background
Mycobacterium tuberculosis remains one of the most significant causes of death from an infectious agent. Rapid and accurate diagnosis of pulmonary and extra-pulmonary tuberculosis (TB) is still a great challenge. The GeneXpert MTB/RIF assay is a novel integrated diagnostic device for the diagnosis of tuberculosis and rapid detection of Rifampin (RIF) resistance in clinical specimens. In 2012, the Arkansas Tuberculosis Control Program introduced GeneXpert MTB/RIF assay to replace the labour-intensive Mycobacterium Tuberculosis Direct (MTD) assay.
Aims
To rapidly diagnose tuberculosis within 2 hours and to detect RIF resistance.
Objectives
1. Describe the procedure used to introduce GeneXpert MTB/RIF assay in the Arkansas Tuberculosis Control Program. 2. Characterize the current gap in rapid M. tuberculosis diagnosis in Arkansas. 3. Assess factors that predict AFB smear-negative but culture-positive cases in Arkansas. 4. Illustrate, with two case reports, the role of GeneXpert MTB/RIF assay in reduction of time to confirmation of M. tuberculosis diagnosis in the first year.
Method
Between June 2012 and June 2013, all sputum smear-positive cases and any others, on request by the physician, had GeneXpert MTB/RIF assay performed as well as traditional M. tuberculosis culture and susceptibilities using Mycobacteria Growth Indicator Tube (MGIT) 960 and Löwenstein-Jensen (LJ) slants. Surveillance data for January 2009–June 2013 were analysed to characterize sputum smear-negative but culture-positive cases. Results Seventy-one TB cases were reported from June 2012–June 2013. GeneXpert MTB/RIF assay identified all culture-positive cases as well as three cases that were negative on culture. Also, this rapid assay identified all 6 smear-negative but culture-positive cases; 2 of these cases are described as case reports.
Conclusion
GeneXpert MTB/RIF assay has made rapid TB diagnosis possible, with tremendous potential in determining isolation of TB suspects on one hand, and quickly ruling out TB whenever suspected.
Full Text:
Mycobacterium tuberculosis remains one of the most significant causes of death from an infectious agent. Rapid and accurate diagnosis of pulmonary and extra-pulmonary tuberculosis (TB) is still a great challenge. The GeneXpert MTB/RIF assay is a novel integrated diagnostic device for the diagnosis of tuberculosis and rapid detection of Rifampin (RIF) resistance in clinical specimens. In 2012, the Arkansas Tuberculosis Control Program introduced GeneXpert MTB/RIF assay to replace the labour-intensive Mycobacterium Tuberculosis Direct (MTD) assay.
Aims
To rapidly diagnose tuberculosis within 2 hours and to detect RIF resistance.
Objectives
1. Describe the procedure used to introduce GeneXpert MTB/RIF assay in the Arkansas Tuberculosis Control Program. 2. Characterize the current gap in rapid M. tuberculosis diagnosis in Arkansas. 3. Assess factors that predict AFB smear-negative but culture-positive cases in Arkansas. 4. Illustrate, with two case reports, the role of GeneXpert MTB/RIF assay in reduction of time to confirmation of M. tuberculosis diagnosis in the first year.
Method
Between June 2012 and June 2013, all sputum smear-positive cases and any others, on request by the physician, had GeneXpert MTB/RIF assay performed as well as traditional M. tuberculosis culture and susceptibilities using Mycobacteria Growth Indicator Tube (MGIT) 960 and Löwenstein-Jensen (LJ) slants. Surveillance data for January 2009–June 2013 were analysed to characterize sputum smear-negative but culture-positive cases. Results Seventy-one TB cases were reported from June 2012–June 2013. GeneXpert MTB/RIF assay identified all culture-positive cases as well as three cases that were negative on culture. Also, this rapid assay identified all 6 smear-negative but culture-positive cases; 2 of these cases are described as case reports.
Conclusion
GeneXpert MTB/RIF assay has made rapid TB diagnosis possible, with tremendous potential in determining isolation of TB suspects on one hand, and quickly ruling out TB whenever suspected.
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