Evaluation of GeneXpert MTB/Rif Assay and the Conventional Methods for Detection of Pulmonary Tuberculosis in Internally Displaced Persons (IDP) Camps in Gombe State

Background: Tuberculosis is a global health problem associated with high morbidity and mortality. Rapid diagnosis of tuberculosis is essential for early disease management.

Aim: This study evaluated the performance of gene expert MTB/ RIF assay for the diagnosis of pulmonary tuberculosis and rifampin (RIF) resistance with conventional methods.

Methods: A total of 130 sputum samples from suspected tuberculosis patients were examined from July 2019 to August 2019.

Results: Fifty-nine patients 59(45.4%) were males and seventy-one 71 patients (54.6%) were females. Seventeen patients (13.07%) had tuberculosis. Of the 17 Confirmed tuberculosis patients, 6(35.2%) were ZN positive, 11(64.7%) were GeneXpert positive and 17(100%) were positive to TB Culture. One sample showed false-positive GeneXpert result. The GeneXpert assay achieved 47.1% sensitivity, 97.3% specificity, 72.7% Positive Predictive Value (PPV) and 92.4% Negative Predictive Value (NPV) while ZN Staining method had 35.3% Sensitivity, 97.27% Specificity, 100% PPV and 91.1% NPV. GeneXpert detected 5(29.41%) Rifampicin resistant TB. The risk factors associated with tuberculosis in this study had HIV (17.6%), Malnutrition (13.8%) and Overcrowding (15.3%).

Conclusion: GeneXpert MTB/RIF assay is a helpful tool for rapid diagnosis and prompt treatment of TB. However, the use of Genexpert does not eliminate the need of conventional microscopy, culture and anti-tubercular sensitivity that are required to monitor the progression of treatment.