Diagnosis and Antimicrobial Susceptibility of Mycobacterium Tuberculosis in a Tertiary Care Hospital in Bangladesh

ABSTRACT

Background: Tuberculosis (TB) is a common condition all over the world but more common in developing countries like Bangladesh38. This is second only to HIV/AIDS as the greatest killer worldwide due to a single infectious agent. In 2013, 9 million people fell ill with TB and 1.5 million died from the disease globally. Approximately 15-20 % of total TB cases are extrapulmonary in non-HIV patients. Among extrapulmonary TB, abdominal tuberculosis (ATB) accounts for 11%-16%. Abdominal TB is difficult to diagnose because of its lack of specific symptoms, low yield of acid-fast bacilli (AFB) on smear and culture due to paucibacillary lesion; and variable manifestations depending upon anatomical localization of the disease. The diagnosis of abdominal TB classically requires histopathological, microbiological and culture confirmation of Mycobacterium tuberculosis. Investigations like Imaging (Ultrasound, Barium X-Rays, and CT scan) and the Mantoux test have only supportive value. Aim of the study The aim of the study was to diagnose modalities and antimicrobial susceptibility in abdominal tuberculosis patients.Material & Methods:This cross-sectional hospital-based observational study was carried out among 73 adult patients with the diagnosis of abdominal TB who met the selection criteria and attended in Gastroenterology department of DMCH through either admission or referral from May 2015 to April 2016.Results:The most frequent symptoms were weight loss (96.9%), abdominal pain (75%), and fever (75%). The most frequent signs were anaemia (34.4%), followed by ascites (27.9%). Basis of diagnosis in abdominal tuberculosis was histolopathogy in 37.5%, Gene Xpert in 28.1%, Positive AFB on culture in 9.4%, ADA value in ascitic fluid (Cutoff >40 IU/L) in 25%, and good clinical response (Based on weight gain and general improvement in wellbeing) to a therapeutic trial of anti-TB treatment in 18.7% patients. Drug sensitivity pattern was analyzed in all three AFB culture-positive patients; resistance was detected in one which showed multidrug resistance (MDR TB).Conclusions:The result of this study highlighted the diagnostic yield of various investigation modalities, particularly newer modalities (Gene Xpert, culture sensitivity in Bactec MGIT 960) and basis of diagnosis in abdominal TB. This study also determined the MTB culture positivity from tissue biopsies in patients with abdominal TB and demonstrated drug-resistant MTB in culture-confirmed abdominal TB.