Diagnostic Utility of GeneXpert (CB-NAAT) and BACTEC (960) and Socio-clinical Profile of Children with Tuberculous Meningitis

Abstract

Introduction: Tuberculosis has always remained puzzling to diagnose. Many children with tuberculous meningitis are diagnosed late due to non-availability of rapid and sensitive diagnostic tests. This study examines the diagnostic utility of GeneXpert test and BACTEC (960) and compares of the sensitivity and specificity of these newer tests. Material and methods: This hospital-based prospective study was conducted in the Dept. of Pediatrics, Sir Padampat Mother and Child Health Institute, SMS Medical College, Jaipur, Rajasthan. Seventy children of >6 month and <18 years age, presenting with fever of >2 weeks duration, headache, signs of meningeal irritation, altered consciousness level and focal neurological deficits were included in the study. Results: Out of 14 patients detected positive by GeneXpert, BACTEC (960) was detected positive in only 4 patients. Out of 56 negative patients detected by GeneXpert, 2 patients were detected positive by BACTEC (960). The sensitivity was 66.67%, specificity was 84.38%, positive predictive value was 28.57%, negative predictive value was 96.63% and accuracy was 82.86%. Conclusions: The GeneXpert has higher sensitivity compared to other currently available diagnostic modalities including liquid culture BACTEC.