Comparison between Gene Expert MTB/RIF Assay and Sputum Microscopy in Diagnosis of Tuberculosis in HIV Patients at Tertiary Care Centre

Background: HIV is a major contributor to the global burden of disease. The HIV patients are prone to develop many opportunistic infections, consequent to immune-deficiency caused by it. TB is the primary cause of death for 10-15% of patients with HIV infection. Tuberculosis (TB) is the most common opportunistic infection among people living with HIV. It is also leading cause of death among people living with HIV. People living with HIV are 29 times more likely to develop active TB disease than those without HIV. Patients with HIV pulmonary tuberculosis co-infection are most likely benefitted by Xpert MTB/RIF assay. Aim and Objective: Comparison between gene expert MTB/RIF assay and sputum microscopy in diagnosis of tuberculosis in HIV patients at tertiary care centre. Material and Methods: The study was cross sectional study conducted in a period of one year from 1 st July 2015 to 30 th June 2016 in the department of medicine at Indira Gandhi medical college and hospital. The study population included the HIV positive patient attending ART clinic/Medicine OPD/Pulmonary medicine OPD admitted in medicine ward. Out of these patients with HIV positive, the diagnosis of tuberculosis was established by gene expert or sputum microscopy .Data collected was entered and analysed in excel sheet, using appropriate statistical software and test of significance. Results: Among 95 patients with HIV infection, the diagnosis of tuberculosis was established in 54 patients after further workup. Seven (26.9%) out of twenty-six with pulmonary tuberculosis were sputum smear positive on Zeihl-Neelsen staining. All patients with sputumsmear-positive tuberculosis had CD4 count below 200cells/cumm. Nineteen (73.1%) out of twenty-six with pulmonary tuberculosis were gene xpertpositive. Sixteen (61.5%) with Xpert MTB/RIF positive tuberculosis had CD4 count below 200cells/cumm. Out of 19 XpertMTB/RIF positive patients only two were rifampicin resistant. Conclusion: This study has shown that the detection of acid fast bacilli by Xpert MTB/RIF increased by 2.7 times as compared to sputum smear microscopy.