Role of Genexpert in Extra Pulmonary Tuberculosis

Diagnosis of extra pulmonary tuberculosis remains especially challenging since the number of Mycobacterium tuberculosis bacilli present in tissues at sites of disease is often low and clinical specimens from deep-seated organs may be difficult to obtain. Histology is time-consuming to undertake and establishing a diagnosis of tuberculosis with high specificity remains difficult. Tissue microscopy after special staining is often negative and when mycobacteria are seen, it is impossible to distinguish Mycobacterium tuberculosis from non tuberculous mycobacterial disease. Reliance on culture, the mainstay of diagnosis, often leads to considerable delays, compromising patient care and outcomes.

Evidence from 138 studies published before 2008 suggested that nucleic acid amplification technologies could not replace conventional mycobacterial tests (microscopy, culture) for diagnosing pulmonary and, especially, extra pulmonary tuberculosis