Abstract:

Background: Report at the lunch of 1^st Nigeria, National Strategic Plan for TB Control report opined that, at the current rate of transmission and development of Tuberculosis, over four million cases are forecasted to occur in Nigeria between 2015 and 2020 (WHO, 2015). Objectives: A study was conducted to examine diagnostic accuracy of GeneXpert, smear microscopy and TB LAM Rapid Urine Antigen Screening Assay for TB and HIV co-infected Population. Methods: 323 specimens from approximately 400 patients were enrolled using probability sampling technique. Selection intensity (CD4 count < 100, critical symptoms of TB and HIV) with stringent conditions was set to reduce eligible population for TB-LAM test. Differences between two groups was tested using t-test in SPSS-24 statistical package. Sensitivity, specificity, NPV and PPV were computed using Diagnostic or Screening Test Evaluation 1.0 using OpenEpi (version 2.3). Results: There were significant differences (P<0.05) among diagnostic accuracy for sensitivity, specificity, PPV, NPV and prevalence rate. The highest sensitivity was in GeneXpert (86.2%, 25/29) while TB-LAM the least sensitivity (57.5%, 46/80). EMS-AFB was significant (P<0.05) and more sensitive than Spot-AFB and TB-LAM. Specificity was significant (P=0.04) and slightly lower in the group tested with GeneXpert (90.8%) as compared to TB-LAM (100%), EMS-AFB (93.1%) and Spot-AFB (92.7%). The proportion of total study population with TB-LAM decreased linearly (23.2% - 7.4%) as the grades increases. Conclusion: This clearly suggest that TB-LAM might not be a robust testing for point of care diagnostics among TB-HIV co-infected Population using Zaria Metropolis of North Western, Nigeria.

Keywords: GeneXpert, Lipoarabinomannan, Tuberculosis, Human Immunodeficiency Virus, Sensitivity.

References:

[1].     Bowles, E.C, Freyee, B., van Ingen, J., Mulder, B., Boeree, M.J & van Soolingen, D. (2011). Xpert MTB/RIF(R), a novel automated polymerase chain reaction-based tool for the diagnosis of tuberculosis. Int J Tuberc Lung Dis; 15: 988-9.

[2].     Corbett, E.L, Marston, B., Churchyard, G.J & De Cock, K.M. (2006). Tuberculosis in sub Saharan Africa: opportunities, challenges, and change in the era of antiretroviral treatment. Lancet; 367: 926-37.

[3].     Davies, G.R, Pillay, M., Sturm, A. & Wilkinson D. (1999). Emergence of multi-drug resistant tuberculosis in a community-based directly observed treatment programme in rural South Africa. Int J Tuberc Lung Dis; 3: 799-804.

[4].     Davies, N.E, Homfray, M & Venables, E.C. (2013). Nurse and manager perceptions of nurse initiated and managed antiretroviral therapy (NIMART) implementation in South Africa: a qualitative study. BMJ Open; 3: e003840.

[5].     Dye, C., & Williams, B.G. (2008). Eliminating human tuberculosis in the twenty-first century.
J R Soc Interface; 5: 653-62.

[6].     Dye, C., Glaziou, P., Floyd, K & Raviglione, M. (2013). Prospects for tuberculosis elimination.
Annu Rev Public Health; 34: 271-86.

[7].     Lawn, S.D, Kerkhoff, A.D, Vogt, M & Wood, R. (2012). Diagnostic accuracy of a low-cost, urine antigen, point-of-care screening assay for HIV-associated pulmonary tuberculosis before antiretroviral therapy: a descriptive study. The Lancet infectious diseases; 12(3):201-9.

[8].     Moodley, P., Shah, N.S, Tayob, N., Connolly, C., Zetola, N., Gandhi, N. (2011). Spread of extensively drug-resistant tuberculosis in KwaZulu-Natal province, South Africa. PLoS One; 6: e17513.

[9].     Peter, J.G, Theron, G., Muchinga, T.E, Govender, U & Dheda, K. (2012). The diagnostic accuracy of urine-based Xpert MTB/RIF in HIV-infected hospitalized patients who are smear-negative or sputum scarce. 27.

[10]. Theron, G., Peter, J., van Zyl-Smit, R., Mishra, H., Streicher, E & Murray, S. (2011). Evaluation of the Xpert MTB/RIF assay for the diagnosis of pulmonary tuberculosis in a high HIV prevalence setting. Am J Respir Crit Care Med 2011; 184: 132-40.

[11]. Theron, G., Zijenah, L., Chanda, D., Clowes, P., Rachow, A & Lesosky, M. (2014) Feasibility, accuracy, and clinical effect of point-of-care Xpert MTB/RIF testing for tuberculosis in primary-care settings in Africa: a multicentre, randomised, controlled trial. The Lancet; 383(9915):424-35.

[12]. Wells, C.D, Cegielski, J.P, Nelson, L.J, Laserson, K.F, Holtz, T.H, & Finlay A, (2007). HIV infection and multidrug-resistant tuberculosis: the perfect storm. J Infect Dis; 196 Suppl 1: S86-107.

[13]. World Health Organization (2015). The use of lateral flow urine lipoarabinomannan assay (LF-LAM) for the diagnosis and screening of active tuberculosis in people living with HIV. WHO Library Cataloguing-in-Publication Data.