A Comparative Study between Genexpert and Smear Microscopy for Diagnosis of Tuberculosis in Paediatric Patients

Diagnosis of tuberculosis (TB) in children is challenging due to insufficient specimen material and the scarcity of bacilli in specimens. In this study we compare the diagnostic yield of geneXpert and smear microscopy in detection of Tuberculosis in children. We have compared sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of GeneXpert with smear microscopy in detection of Mycobacterium Tuberculosis in children. Out of the total 100 cases of suspected tuberculosis evaluated in a tertiary care hospital, 80 patients were clinically TB positive and 20 patients were clinically TB negative. Both genexpert and AFB smear microscopy showed 100 % specificity and positive predictive value. However sensitivity of genexpert was 48.7 %& that of AFB smear was 16.3. Negative predictive value of genexpert was 32.8 %& that of AFB smear microscopy was 22.9 %. Sensitivity of GeneXpert was approximately 3 times higher than AFB smear microscopy and Negative predictive value of GeneXpert is also higher as compared to AFB smear microscopy. Hence genexpert was found to be a better diagnostic test as compared to smear microscopy and can significantly reduce false negatives and the delay in treatment initiation, reducing premature death and ongoing transmission