Comparison of recoveries of Mycobacterium tuberculosis using the Automated BACTEC MGIT 960 System and Lowenstein-Jensen Medium in clinically suspected cases of tubercular meningitis in children

Abstract

Background: Tubercular meningitis (TBM) remains a major complication in children with a considerable mortality and morbidity. Inconsistent and variable clinical features coupled with lack of rapid, sensitive and specific tests poses a diagnostic challenge to the clinical acumen. This study was carried out to diagnose TBM by a combination of direct microscopy by Ziehl-Neelsen (ZN) staining, culture by conventional Lowenstein Jensen (LJ) media and Bactec MGIT 960 system in clinically suspected cases TBM and compare the utility of these diagnostic modalities in the diagnosis of paediatric TBM. Methods: A total of 50 cerebrospinal fluid (CSF) samples from suspected cases of TBM in children aged 0-12 years of age were processed for direct acid fast bacilli (AFB) smear examination, and culture on LJ media and automated Bactec MGIT 960 system. Results: The study comprised of 32 male and 18 female patients in the age group of 0-12 years with a male to female ratio of 1.77: 1. 1 (2%) out of 50 samples was positive for AFB by ZN staining. Overall culture was positive in 15 cases (30%). Culture by LJ media was positive in 4 (8%) of the cases while culture by Bactec MGIT 960 system was positive in 14 cases (28%). The mean time of detection of Mycobacterium tuberculosis in LJ media and MGIT were 13.2 days and 32.4 days, respectively. Conclusion: Automated Bactec MGIT 960 system increases the sensitivity of diagnosing TBM in comparison to conventional microscopy and culture and reduces the mean time to diagnosis.