Evaluation of GeneXpert MTB/Rif Assay and the Conventional Methods for Detection of Pulmonary Tuberculosis in Internally Displaced Persons (IDP) Camps in Gombe State
Lynn Maori
*
Molecular Diagnostic Laboratory, State Specialist Hospital Gombe, Gombe State, Nigeria.
Kabiru Muhammed
Department of Medical Microbiology, School of Medical Laboratory Science, Usmanu Danfodio University, Sokoto, Sokoto State, Nigeria.
Garba Ibrahim
Department of Medical Microbiology, School of Medical Laboratory Science, Usmanu Danfodio University, Sokoto, Sokoto State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
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.
Keywords: GeneXpert, TB culture, ZN staining, tuberculosis, malnutrition and overcrowding.