Evaluating the diagnostic accuracy of gene xpert analysis in pediatric pulmonary tuberculosis: a prospective clinical study in North-Western India

Background: The diagnosis of tuberculosis (TB) by microbiological tests is a major challenge particularly in children. The use of Xpert analysis, a rapid genetic testing modality is not widely reported in our locality. The aim of the study to evaluate the diagnostic accuracy of Gene xpert analysis in diagnosis of pediatric Pulmonary TB.Methods: A prospective hospital-based study was conducted among 140 participants with symptomatology pertaining to pulmonary TB as per Revised national tuberculosis control program (RNTCP, India) criteria. The Xpert testing (GXT) was performed as per standards and was compared with erythrocyte sedimentation rate (ESR), tuberculin test (TT) and chest X-rays (CXR). The obtained results were reported in terms of Sensitivity %, Specificity %, Positive Predictive Value % (PPV) and Negative Predictive Value % (NPV) for comparisons. The receiver operating curve (ROC) analysis was employed to evaluate the accuracy of diagnosis.Results: The GXT was positive (10.71 %) in suspected TB patients. TT has significantly (10 %) with a73.33% sensitivity, 93.60% specificity and a PPV of 57.89 % when compared with xpert. The ESR showed a sensitivity of 53.33% and a specificity of 56%. The CXR showed sensitivity of 93.33%. The ROC analysis showed that TT had a higher confidence interval (0.699-0.970) t5`han other methods. The Rifampicin resistance was found 7.5% (n=2) of 15 GXT positive cases.Conclusions: The xpert based diagnosis of gastric lavage samples after a tuberculin test (TT) had high sensitivity and specificity, followed by chest X ray while the ESR had lower clinical accuracy. The ‘gene xpert analysis’ is highly useful rapid tool for diagnosis of children with TB.