Performance evaluation of Abbott real-time PCR in the diagnosis of Mycobacterium tuberculosis in Addis Ababa, Ethiopia: A cross-sectional descriptive study

Abstract

Abstract Background In 2018, an estimated 10 million people developed tuberculosis, of whom more than 1.45 million died. The microscopy method used in most tuberculosis high burden and resource-limited countries is less accurate for diagnosing the disease. Thus, evaluation of the available diagnostic modalities in the country is crucial, and this study aimed to evaluate the performance of Abbott real-time PCR as a diagnostic technique for tuberculosis in Ethiopia. Methods A cross-sectional survey was conducted using sputum specimens collected from 150 presumptive tuberculosis patients from both public and private health facilities in Addis Ababa, Ethiopia, from May to June 2019. The laboratory investigation was conducted at the National Reference Laboratories of the Ethiopian Public Health Institute (EPHI). Results This finding indicated that 84.7% (127/150) and 61.3% (92/150) were smear and culture-negative, respectively. The overall diagnostic sensitivity of the Abbott real-time polymerase chain reaction (PCR) technique for the diagnosis of tuberculosis was 89.7% (52/58), that for smear-negative was 80.6% (29/36), and that for specificity was 92.4% (85/92). Drug resistance testing demonstrated diagnostic specificities of 87.5% and 100% for isoniazid and rifampicin, respectively, and a sensitivity of 92.3% for both. Conclusions This study demonstrated an outstanding performance of the Abbott real-time PCR technique for diagnosing tuberculosis using sputum specimens using culture as a reference standard. Thus, we recommend that Ethiopia's ministry and tuberculosis program implementers consider the Abbott real-time PCR technique for diagnosing tuberculosis and drug resistance testing, which is likely to be included in the national guidelines.