Gene Xpert MTB/RIF Assay: A New Hope for Extrapulmonary Tuberculosis

Abstract

The diagnostic efforts for extrapulmonary tuberculosis (TB) have been severely hampered by the lack of diagnostic tests that are accurate, simple to use and can be applied at the point of clinical care. This has been further enhanced by the widespread inability to test for drug resistance. Gene Xpert® MTB/RIF test offers new and essential possibilities for the diagnosis of TB especially extrapulmonary TB and rifampicin resistance. This unique test can be used almost everywhere with minimal technical expertise, enabling diagnosis of TB and simultaneous assessment of rifampicin resistance to be completed within 2 h. In low-income countries, however, its cost, environmental limitations and difficulties involved in supply and maintenance are major obstacles. While it may be suitable for major reference hospitals, operational research is needed to evaluate the test and its additional yield above high-quality smear microscopy. In high burden countries like India, WHO in 2010 endorsed some guidelines for implantation of Gene Xpert® MTB/RIF test for diagnosis of TB and drug resistance.