Analytical Evaluation of Mycobacterium tuberculosis Detection in a Local Comprehensive Tuberculosis Center Following the Introduction of GeneXpert: A Cartridge‑Based Nucleic Acid Amplification Test

Abstract

Background: The policies and methods for preliminary evaluation of Mycobacterium tuberculosis(MTB) are evolving as TB becomes resistant to drugs worldwide. Evaluating the effectiveness of New GeneXpert as a first‑line protocol for replacing AFB/ZN microscopy in TB evaluation for more system future rollout was paramount for effective TB detection. Aim: The research was a retrospective analytical cohort study, evaluating the detection rates of MTB using Direct‑AFB microscopy and GeneXpert among samples from TB suspects. Materials and Methods: Data were collated from the National TB and Leprosy Control Programme register and laboratory records. The study period was from February 2015 to October 2017. The study period was divided into three, 11 months each, representing different preliminary testing policy. Proportions and rates were determined using Microsoft Excel and Chi‑square analysis. A P ≤ 0.05 was considered statistically significant. Results: A total of 1931 sample results were analyzed, of which 99.9% were sputum. Nearly 502,578 and 177 samples underwent AFB/ZN microscopy technique, whereas 0, 40, and 634 samples underwent GeneXpert for the respective three cohort periods. The results showed that MTB was present at rates of 8.17%, 5%, and 3.39% for ZN, whereas GeneXpert was 15% and 12.6% for the 2nd and 3rd cohort periods only. In addition, 10% detected by GeneXpert were rifampicin drug resistant, and 50% (4) were placed on therapy for resistant strain GeneXpert improved TB detection significantly. Conclusion: GeneXpert could improve the detection of MTB/RIF strains in developing countries through partnership and global funding for TB/ART centers.