Molecular Diagnosis of Extrapulmonary Tuberculosis and Rifampicin Resistance Using Genexpert MTB/RIF in Morocco

Extrapulmonary tuberculosis (EPT) is a form of tuberculosis caused by Mycobacterium tuberculosis, affecting sites other than the lungs. GeneXpert MTB/RIF is an automated PCR-based assay for rapid detection of the Mycobacterium tuberculosis complex and rifampicin resistance and is recommended by the WHO as a reliable alternative. This study aimed to evaluate the performance of GeneXpert in diagnosing EPT in a hospital laboratory in Morocco. A retrospective descriptive study over 36 months included 155 confirmed EPT cases, with a mean age of 34.32 ± 20.67 years and a male-to-female ratio of 0.87. The most frequent site was neuro-meningeal, followed by lymphatic and digestive sites. Tuberculosis was sensitive in 98.71% of cases, with rifampicin resistance in 1.29%. Positivity rates were 0.57% for microscopy, 14.61% for GeneXpert, and 32.26% for culture. Compared to culture, GeneXpert showed a sensitivity of 85.71%, specificity of 88.63%, and a negative predictive value of 100%. GeneXpert is a rapid and effective diagnostic tool and may be considered a reference method for EPT diagnosis.