DIAGNOSTIC ACCURACY OF GASTRIC ASPIRATE (GENEXPERT&ACID-FAST BACILLUS) IN PATIENTS WITH SUSPECTED PLEURAL TUBERCULOSIS.

Abstract

Introduction: Globally, pulmonary tuberculosis is a vital communicable disease. Amongst countries with the highest burden of Tuberculosis (TB), Pakistan is now on 5th position, together with the 4th greatest burden of drug-resistant TB worldwide. Detection of early-stage TB cases is important, for the successful treatment and reduction of transmission. For the rapid diagnosis of TB, the World health organization endorsed the GeneXpert MTB/RIF (Mycobacterium TB/Rifampin), in which an automated cartridge-based molecular technique detects MTB and rifampicin resistance within two hours. The study aimed to determine the diagnostic accuracy of gastric aspirate (GeneXpert and Acid-fast bacilli Smear) in patients with suspected pleural TB tanking pleural biopsy as the gold standard. Materials and Methods: This cross-sectional study was conducted at the department of pulmonology Jinnah Medical Postgraduate College, Karachi, Pakistan from July-December 2019 among 200 patients suspected with pleural effusion of 30-70 years of age with either gender. The gastric aspirate was sent for Acid-fast bacilli (AFB) smear andGeneXpert. Meanwhile,an ultrasound-guided pleural biopsy was also done. To check the diagnostic accuracy of AFBsmear and geneXpert, results were compared with pleural biopsy. Results: Mean of age and duration of symptoms was 35.38±6.32 years and 6.23±2.41 weeks respectively. The diagnostic accuracy of GeneXpert and AFB smear was 65.50% and 90.05% respectively forthe diagnosis of pleural effusion. The sensitivity, specificity, positive predictive value, and negative predictive value for GeneXpert was 29.03%, 97.20%, 90.00%, and 61.18%, respectively while for AFB sputum, the values were 83.87%, 93.48%, 85.25%, and 92.81% respectively. Conclusion: It is concluded that AFB smear has high diagnostic accuracy with high sensitivity and specificity as compared to GeneXpert. AFB is a cheap, readily available, and non-invasive modality that is reasonably good and relatively comparable with the biopsy in the diagnosis of pleural TB.