Performance of conventional laboratory tests and Xpert MTB/RIF in the diagnosis of tuberculosis

The laboratory diagnosis of tuberculosis (TB) represents a continuous challenge due to the variability and complexity of the required clinical samples. Although molecular technologies have considerably improved diagnostic accuracy, their combined use with traditional methods like microscopy and bacterial culture remains a subject of debate. This study aims to compare the performance of microscopy, bacterial culture on Löwenstein-Jensen medium, and the molecular Xpert MTB/RIF test in diagnosing pulmonary and extrapulmonary TB. In this retrospective study, conducted over a period from January 2016 to January 2023, data were collected from pulmonary TB and extrapulmonary TB samples of patients hospitalized in the pneumonology departments of the Bihor County Emergency Hospital. The study included 1796 patients, of whom 85.2% had samples collected from the respiratory tract. The variability of sensitivity and specificity depending on the type of sample indicates the need for a differentiated approach in diagnosis. The results show that the Xpert MTB/RIF test detected a higher number of positive cases (16%) compared to microscopy (9%) and bacterial culture (15%). Statistical analysis revealed a high sensitivity and specificity of Xpert MTB/RIF, suggesting superior accuracy compared to traditional methods. Our conclusions underline the importance of the Xpert MTB/RIF as a valuable tool in the diagnosis of TB, but it is recommended to use it in combination with other methods to ensure a complete and efficient diagnosis.