Comparative Diagnostic Accuracy Of Genexpert, AFB Microscopy, LAMP And Symptom-Based Screening Against Culture In Pulmonary Tuberculosis
DOI:
https://doi.org/10.64252/q66tsj91Keywords:
Pulmonary tuberculosis, Diagnostic accuracy, GeneXpert MTB/RIF, Loop-mediated isothermal amplification (LAMP), AFB microscopy, Symptom-based screeningAbstract
Drug resistance and continued transmission of pulmonary tuberculosis (TB) are caused by delayed diagnosis, which is still a significant worldwide health concern. Mycobacterial culture is the gold standard for diagnosing tuberculosis, although it takes a lot of time and resources. In order to assess their usefulness in government healthcare settings with limited resources, this study compares the diagnosis accuracy of four alternative techniques; GeneXpert, AFB microscopy, LAMP, and symptom-based screening vs against culture.
282 adult patients exhibiting pulmonary tuberculosis symptoms participated in a cross-sectional observational study. AFB microscopy, LAMP, symptom-based screening, GeneXpert, and culture (reference standard) were used to examine each subject. Sensitivity, specificity, receiver operating characteristic (ROC) curves, positive predictive value (PPV), and negative predictive value (NPV) were used to evaluate diagnostic accuracy.
Out of 282 subjects, 61.4% had TB confirmed by culture. Among the diagnostic methods, GeneXpert had the greatest positivity rate (76.2%), followed by symptom-based screening (88.3%), chest X-ray (70.3%), and AFB microscopy (69.0%). The positive rate for LAMP was the lowest at 39.7%. When compared to alternative techniques, GeneXpert showed acceptable specificity (66.0%) and better sensitivity (84.8%). Despite its high sensitivity (95.5%), symptom-based screening has a high false positive rate due to its low specificity (18.8%). LAMP exhibited the highest specificity (81.3%) but the lowest sensitivity (40.4%). The best diagnostic performance, according to ROC analysis, was GeneXpert (AUC: 0.801).
GeneXpert proved to be the most accurate and well-rounded diagnostic tool, especially in environments with inadequate infrastructure. Although symptom-based screening is helpful for preliminary triage, confirmation testing is necessary due to its low specificity.
