DETECTION OF PULMONARY TUBERCULOSIS IN SUSPECTED CASES USING THE GENEXPERT ASSAY AT INTERNAL MEDICINE DEPARTMENT

The early diagnosis of pulmonary tuberculosis remains a critical priority in clinical practice. Although the GeneXpert MTB/RIF assay has been recommended for tuberculosis diagnosis, its implementation has not been widely adopted in many regions of Vietnam. This study aimed to evaluate the diagnostic value of the GeneXpert MTB/RIF assay on sputum samples for detecting pulmonary tuberculosis and to compare its results with those from direct sputum smear microscopy (AFB). A cross-sectional descriptive study was conducted on 270 patients with suspected pulmonary tuberculosis who were examined and treated at the Internal Medicine Department, Thong Nhat Hospital, between January 2024 and July 2025. Among the participants, 72.2% were male and 27.8% were female. The mean age was 79.5 ± 15.1 years, and the mean body mass index (BMI) was 21.1 ± 3.4 kg/m². The detection rate of tuberculosis was 14.1% using the GeneXpert MTB/RIF assay, compared to 4.8% by AFB smear microscopy.Compared to AFB smear microscopy, the GeneXpert MTB/RIF assay demonstrated a sensitivity of 84.6%, a specificity of 89.5%, a positive predictive value (PPV) of 28.9%, and a negative predictive value (NPV) of 99.1%. The rate of rifampicin resistance among detected cases was 7.9%. Patients with suspected pulmonary tuberculosis presented with diverse clinical manifestations and comorbidities. The GeneXpert MTB/RIF assay on sputum samples showed high sensitivity and specificity for diagnosing pulmonary tuberculosis, with a rifampicin resistance rate of 7.9%.