Comparison of Different Methods for the Diagnosis of Mycobacterium Tuberculosis and Rifampin-Resistance

Xpert MTB/RIF is recommended by the World Health Organization (WHO) for a rapid and simultaneous detection of Mycobacterium tuberculosis (Mtb) and rifampicin resistance specific to patients who have symptoms and signs.

The aim of this study was to evaluate the diagnostic significance possessed by various assays specific to the detection of Mtb. This study included 345 suspected TB patients who received treatment at the Shandong Public Health Clinical Center during May 2019 and August 2019. Related data included demographics, gender, age, past medical history (PMH), country of birth, country of residence, clinical information and laboratory test outcomes. The smear method was performed three times, the BD960 method was conducted two times and the MTB/ RIF and Xpert Ultra (phlegm precipitation) assays were performed once. All methods were completed simultaneously.

The Xpert Ultra MTB (phlegm precipitation) method exhibited the highest consistency and sensitivity, followed by the Xpert MTB, Mtb culture, and smear methods, respectively. The Xpert Ultra MTB method also exhibited a significantly higher detection rate relative to the smear method (X2 = 13.411, p < 0.001).

Xpert MTB/RIF along with Xpert Ultra (phlegm precipitation) exhibited higher sensitivity specific for the diagnosis of TB and rifampicin-resistance. The combined effects of these four methods showed outstanding sensitivity compared with single methods alone.