Evaluation of XpertMTB/RIF performance for diagnosis of tuberculosis among HIV positive patients in northern Tanzania

Background: Diagnosis of tuberculosis (TB) in patients co-infected with HIV poses an important challenge because of the low sensitivity and specificity of microscopy, the standard diagnostic method. This study aimed to evaluate the performance of the XpertMTB/RIF tool for TB diagnosis among TB-HIV co-infected patients.
Methods: This was a cross-sectional analytical study conducted at Kibong’oto Infectious Disease Hospital in northern Tanzania and involved 69 patients. The performance of the XpertMTB/RIF and microscopy using LJ culture were determined and compared. Demographic, clinical, laboratory and radiological data were collected.
Results: XpertMTB/RIF had a higher sensitivity (100%), specificity (100%), positive predictive value (79.2%) and negative predictive value (98.9%) as compared to microscopy. There was a strong correlation between XpertMTB/RIF, microscopy and Löwenstein–Jensen (LJ) culture in terms of their sensitivity and specificity.
Conclusion: While using TB symptoms screening tool alone in HIV infected individuals may result into overtreatment, relying on microscopy alone has the potential of TB under-diagnosing, miss-diagnosing and delayed treatment. Our results show XpertMTB/RIF to be highly sensitive and specific to detect all culture positive TB cases among HIV patients. We recommend the adoption of XpertMTB/RIF as an early TB diagnosis tool among HIV patients for early detection of TB among HIV patients.