Accuracy of GeneXpert in Diagnosis of Smear Negative Tuberculosis: A Cross-Sectional Study

Abstract

Objective: This study was aimed to compare the diagnostic accuracy of GeneXpert in smear negative as compared to smear positive pulmonary tuberculosis patients.
 Methods: This comparative cross sectional study was undertaken at Health Research Institute (National Institute of Health) TB Research Centre, Pulmonology King Edward Medical University Lahore, Pakistan. A total of 101 patients in each smear negative and positive groups were included. After taking the informed consent a predesigned questionnaire was used to collect the data.
 Results: A total of 202 patients consisting of 94 (46.5%) male and 108 (53.5%) females with mean age of patients as 39.83±18.14 years were included in this study. Highest proportion of 45% patients remained to be in age range of 18-35 years. Culture presented the highest accuracy of 96.1% with sensitivity, specificity and positive predictive value of 95.9%, 100%, and 100% respectively while GeneXpert remained to be 94.6%, 94.9%, 80%, and 99.5% respectively in this study.
 Conclusion: Accuracy of GeneXpert is excellent in diagnosis of smear positive pulmonary tuberculosis patients and very well in diagnosing smear negative pulmonary TB patients and a great addition in early and definite diagnosis of TB and keeps the ability to confirm around 75% smear negative pulmonary tuberculosis.

Diagnostic Accuracy of GeneXpert in Pulmonary and Extra-pulmonary Specimens in Tertiary Care Settings of South Punjab

“…A pre-designed questionnaire was used to collect demographic information, history, and other required information. Direct and concentrated smears were prepared from one sample and processed for culture on LJ medium 12 while second sample was processed for GeneXpert 13 . Statistical Analysis: Data was entered and analyzed in SPSS.…”