Observational Study of Suspected Cases of the Abdominal Tuberculosis on the Basis of Cartridge Based Nucleic Acid Amplification Test (CBNAAT) Compared with Histopathology Examination

Background: Tuberculosis is a chronic granulomatous infectious disease, primarily affecting the lungs. However, it is a systemic infection and may involve any organ. Most of the abdominal tuberculosis cases are either missed or diagnosed late, both this late and missed diagnosis contributes to high mortality and morbidity. Aim: Comparison of diagnostic accuracy of CBNAAT and Histopathological examination in suspected case of abdominal tuberculosis. Methods: This is a prospective observational study on 37 operative cases with sub-acute intestinal obstruction, intestinal stricture, intestinal adhesion, appendicular lump, intestinal perforation and mesenteric lymphadenopathy with consecutive sampling during the period of 2 years (January 2021– December 2022) conducted in the department of surgery, JLN Hospital Ajmer. Results: Mean age of study population was 41.58±22.01 yrs. (age range of 7 month -76 yrs.). Adhesion (35.14 %) was found to be the most common intra operative finding followed by Intestinal perforation (32.43%), SAIO, or RIF mass (32.43%). About 73% patients were found to be tuberculosis positive in histopathology examination whereas only 24 % of the patients were found to be microbiologically confirmed for mycobacterium tuberculosis on CBNAAT. For CBNAAT sensitivity was 88.88% and specificity was 32.14%. Positive predictive value was 29.62% and negative predictive value was 90%. Mean length of hospital stay was 15.43±5.96 days. 2.70% had recurrence after discharge from hospital. Conclusion: In abdominal tuberculosis, CBNAAT had high sensitivity and low specificity, making it more a screening tool than a diagnostic tool.