Accuracy of GenoQuick MTB test in detection of Mycobacterium tuberculosis in sputum from TB presumptive patients in Uganda

Sylvia Kaswabuli; Emmanuel Musisi; Patrick Byanyima; Abdul Sessolo; Ingvar Sanyu; Josephine Zawedde; William Worodria; Laurence Huang; Alfred Okeng; Freddie Bwanga

doi:10.1177/20503121221116861

Accuracy of GenoQuick MTB test in detection of Mycobacterium tuberculosis in sputum from TB presumptive patients in Uganda

SAGE Open Med. 2022 Aug 16:10:20503121221116861. doi: 10.1177/20503121221116861. eCollection 2022.

Authors

Affiliations

¹ Infectious Diseases Research Collaboration, Kampala, Uganda.
² Division of Infection and Global Health, School of Medicine, University of St Andrews, St Andrews, UK.
³ Division of HIV, Infectious Diseases & Global Medicine, University of California San Francisco, San Francisco, CA, USA.
⁴ Division of Pulmonary and Critical Care Medicine, University of California San Francisco, San Francisco, CA, USA.
⁵ MBN Clinical Laboratories, Kampala, Uganda.
⁶ Department of Medical Microbiology, Makerere University College of Health Sciences, Kampala, Uganda.

Abstract

Objective: The objective of the study was to determine the diagnostic performance of the GenoQuick MTB test on heated sputum against the conventional Lowenstein-Jensen Mycobacterium tuberculosis culture as the reference method for tuberculosis diagnosis.

Introduction: Fast, reliable, and easy-to-use tests for tuberculosis diagnosis are essential to achieving the Sustainable Development Goal of diagnosing and treating 90% of tuberculosis patients by 2030. We evaluated the diagnostic performance of the GenoQuick MTB, a polymerase chain reaction-lateral flow test, in Uganda, a resource-constrained, high tuberculosis- and HIV-burden setting.

Methods: Fresh sputum samples from presumptive tuberculosis patients at Mulago Hospital were tested for M. tuberculosis using smear microscopy, GenoQuick MTB test, and Lowenstein-Jensen culture. For the GenoQuick MTB test, mycobacterial DNA was extracted by heating sputum at 95°C for 30 min while DNA amplification and detection were done following the manufacturer's protocol (Hain Lifescience, Nehren, Germany). Sensitivity, specificity, and kappa agreements were calculated against Lowenstein-Jensen M. tuberculosis culture as a reference test using STATA V12.

Results: Of the 86 tested samples, 30.2% had culture-confirmed pulmonary tuberculosis. Overall, sensitivity was higher for GenoQuick MTB (81%, 95% confidence interval: 60%-93%) than for smear microscopy (69%, 95% confidence interval: 48%-86%). Among people living with HIV, sensitivity was identical for GenoQuick MTB and smear tests (75%, 95% confidence interval: 42%-95%). Contrastingly, smear had a higher overall specificity (98%, 95% confidence interval: 91%-100%) than for GenoQuick MTB (92%, 95% confidence interval: 81%-97%). A similar trend of specificity was observed among the people living with HIV for smear microscopy (100%, 95% CI: 87%-100%) and for GenoQuick MTB (96%, 95% confidence interval: 81%-100%).

Conclusion: The GenoQuick MTB test could be a potential tuberculosis diagnostic test given its higher sensitivity. Evaluation of this test in larger studies is recommended.

Keywords: Diagnosis; GenoQuick MTB; Mycobacterium tuberculosis; and resource-limited settings; diagnostic accuracy; nucleic acid amplification.

Abstract

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