Molecular diagnosis by cartridge based nucleic acid amplification test (xpert mtb /rif assay) - an early diagnosis and breakthrough in initiation of treatment in childhood tb meningitis and primary mdr cases

Background: Tuberculosis (TB) still remains the major public health threat in India. Early diagnosis, so as to initiate early treatment is a priority as any delay, may complicate the prognosis further leading to the failure of an effective control. India accounts for 6% incidence of pediatric TB cases in a population that has 40% as estimated latent TB cases. Pediatric samples as the key population. Tuberculosis remains the commonest cause of childhood meningitis in high burden countries (Raj et al., 2014). India accounted for highest number of TB deaths among children in the year 2015 followed by Nigeria and China. Out of which TBM stands to be the most common cause of morbidity. Extra pulmonary TB accounts for 25% out of the total TB cases reported among which the most severe form being the TBM. Though severe and difficult to diagnose due to lack of specific tests to get confirmed, CBNAAT is the only solution for microbiological confirmation of the disease for early treatment initiation and reduction of morbidity and mortality. Previously, due to lower case detection rates owing to inadequate diagnostic facilities of higher analytical sensitivity the mortality and morbidity continued to be in the higher range and empirical treatment modality was the main stay till the Cartridge based Nucleic acid amplification tests came into existence. The increase in the case detection for Tubercular meningitis at a manageable stage of the disease would help in decreasing the mortality rates. The study explores the increased case detection rates among pediatric population suffering from tubercular meningitis from referral units to Intermediate Reference Lab Kolkata. CSF from the pediatric patients has not been very difficult procedure though invasive specially in the pediatric age group and can be practiced at peripheral unit having CBNAAT facility. Methods: Cerebrospinal fluid from pediatric patients showing obvious clinical signs of meningitis were collected from tertiary unit linked to Intermediate Reference Laboratory Kolkata and tested on CBNAAT by Xpert Mycobacterium tuberculosis Rifampicin (MTB/RIF) (Cepheid) along with all the pulmonary and extra pulmonary samples based on the manufacturer’s instruction. The data were captured in the Xpert software automatically during the tests and exported to the Microsoft Excel sheets for further analysis. A defined study design against each and every objective was set up to analyze the effective detection of tubercular meningitis case and their resistance to Rifampicin along with the other pulmonary and extra pulmonary samples. Result and Conclusions: The study concluded that confirmation of tubercular meningitis cases by the help of CBNAAT. The detection of microbiologically confirmed tuberculosis by these specimen sent from the referral unit linked with IRL Kolkata for pulmonary and extra pulmonary cases along with tubercular meningitis cases is significant and facilitate the early initiation of treatment for tuberculosis and more so to those who are newly detected as MDR TB especially below the 6 months of age. About 5% prevalence and around 4.9% incidence is an alarming situation in the TB control scenario of West Bengal. The positive case detection among the CSF samples was found to be more in the 0.6 to one year group followed by the age group of one to five years. The percentage positivity of CSF is recorded as 2.38% and the percentage of Rifampicin resistance among positive cases from CSF was found to be 13.79% (n=28).