Role of CBNAAT in Diagnosing of Extra-Pulmonary Tuberculosis at a Tertiary Care Centre in a City of Karnataka: A Cross Sectional Study

Abstract

Background: Cartridge based nucleic acid amplification test(CBNAAT) detects the presence of TB bacilli and also
Rifampicin susceptibility.This test is currentlyrecommended as a ‘‘first line’’ fast diagnostic test inhigh TB burden
countries like India.
Aim & Objective: 1. To assess the yield of CBNAAT in detecting extra-pulmonary tuberculosis for patient
attending S.S.I.M.S & RC, Davanagere.
2. To assess the Rifampicin susceptibility in samples of presumptive extra-pulmonary TB patients using CBNAAT.
Settings and Design: Cross sectional study was conducted among the patients after screening them with symptoms
suggestive of extra-pulmonary TB coming to S. S.I.M.S & RC. Davangere.
Methods and Material: 107 samples were collected and subjected to CBNAAT for detection of Mycobacterium
tuberculosis and Rifampicin Susceptibility.
Statistical analysis used: chi square test was applied to find out the association between Extra-pulmonary
Tuberculosis with demographiccharacteristics and to find out the association between CBNAAT with demographic
characteristics.
Results: The yield of CBNAAT was of sensitivity of 100%, specificity of 98.7%, Positive predictive value (PPV) of
96.9%, Negative predictive value(NPV) was 100% and Accuracy was 99.1%.
Conclusions: This study reinforces the importance of CBNAAT which has an impact on early detection, treatment
and outcome of Extra-pulmonary Tuberculosis.