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 xpert positive. 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.

1. Ortblad KF, Lozano R, and Murray CJ.The burden of HIV: insights from the GBD2010. AIDS. 2013; 27: 2003–
2. World Health Organization. Global tuberculosis report 2014. Geneva: WHO 2014.Availablefrom:URL:http://apps.who.int/iris/bitstream/10665/137094/1/9789241564809_eng.pdf?ua=1. (Last accessed on 18.16.2016).
3. LondheyHIV and Tuberculosis-A “Cursed Duo” in theHAART Era, J Assoc Physicians India 2009; 57: 681-82.
4. Longo Dan L, Kasper Dennis L, Jameson J et Harrison’s Principles of Internal Medicine, 19^th edMcGraw-Hill, 2015: 1216-54.
5. Arzu N. Zeka, Sezai Tasbakan, Cengiz Cavusoglu. Evaluation of the Gene Xpert MTB/RIF Assay for Rapid Diagnosis of Tuberculosis and Detection of Rifampin Resistance in Pulmonary and Extrapulmonary Specimen Journal of Clinical Microbiology. Dec, 2011; 49 (12) 4138-41.
6. Longo Dan L, Kasper Dennis L,Jameson J et al. Harrison’s Principles of Internal Medicine .19th edMcGraw-Hill2015:1133
7. World Health Organization: Automated real-time nucleic acid amplification technology for rapid and simultaneous detection of tuberculosis and rifampicin resistance: Xpertmtb/rif Policy statement 2011.Available from URL http://whqlibdoc.who. int/publications/2011/9789241501545_eng.pdf.
8. Southwick F. Chapter 4 Pulmonary Infections. Infectious Diseases: A clinical Short Course. 2^nded McGraw-Hill Medical Publishing Division,2007; 313-14.
9. Lawn SD, Zumla AI. Tuberculosis. 2011 Jul 2;378(9785):57-72.
10. Zumla A, Raviglione M, Hafner R et al. Tuberculosis. N Engl J Med.2013 Feb 21;368(8):745-55.
11. Corbett EL, Marston B, Churchyard GJ et al. Tuberculosis in sub-Saharan Africa: opportunities, challenges, and change in the era of antiretroviral treatment. Lancet 2006; 367: 926-37.
12. Golub JE, Mohan CI, Comstock GW et al. Active case finding of tuberculosis: historical perspective and future prospects. Int J Tuberc Lung Dis.2005 Nov;9(11): 1183-203.
13. Wood R,Middelkoop K,Myer L et al. Undiagnosed tuberculosis in a community with high HIV prevalence: implications for tuberculosis control. Am J RespirCrit Care Med. 2007 Jan 1;175(1):87-93.
14. Davis JL, Worodria W,Kisembo H et al. Clinical and radiographic factors do not accurately diagnose smear-negative tuberculosis in HIV-infected inpatients in Uganda: a cross-sectional study. PLoS One. 2010 Mar 26;5(3):e9859.
15. Boehme CC, Nabeta P, Hillemann D et al. Rapid Molecular Detection of Tuberculosis and Rifampin Resistance. N Engl J Med. 2010;363:1005–15.
16. Steingart K, Sohn H,Schiller I et al. Xpert® MTB / RIF assay for pulmonary tuberculosis and rifampicin resistance in adults. Cochrane Database Syst Rev. 2013 Jan 31;(1):CD009593.
17. Chang K, Lu W, Wang J et al. Rapid and effective diagnosis of tuberculosis and rifampicin resistance with Xpert MTB/RIF assay: a meta-analysis. J Infect.2012 Jun;64(6):580-8.
18. World Health Organization (WHO) (2011) Rapid Implementation of the Xpert MTB / RIF diagnostic test: technical and operational “How-to”; practical Geneva.
19. Guidelines for prevention and management of common opportunistic infections/malignanciesamong HIV –infected adults and adolescents. NACO, 2007; 12-17.
20. Agarwal U, KumarA, Behera Profile of HIV-Associated Tuberculosis at a Tertiary Institute in Setting of Free Anti-Retroviral Therapy, J AssocPhysicians India 2009;57: 685-690
21. Bhagyabati S, Naorem S, Singh J et al. HIV and TB Co-infection. Journal, Indian Academy of Clinical Medicine 2005;6(3):220-223.
22. Ghiya R, Naik E, Casanas B et al. Clinical-epidemiological profile of HIV/TB coinfected patients in Vadodara, Gujarat. Indian journal of sexually transmitted diseases 2009; 30:10-15.
23. Sharma SK, Kohli M, Yadav RN et al. Evaluating the Diagnostic Accuracy of Xpert MTB/RIF Assay in Pulmonary Tuberculosis. PLoS ONE 2015;10(10): e0141011.
24. Kamath R, Sharma V, Pattanshetty S et al. HIV–TB coinfection: Clinico-epidemiological determinants at an antiretroviral therapy center in Southern India. Lung India 2013; 30(4):302-06.

Dr Kamini Randhawa

Junior resident, Department of Anaesthesia, IGMC Shimla, India