The Food and Drug Administration (FDA) has granted clearance for the Cepheid Xpert MTB/RIF Assay to help determine if patients with suspected tuberculosis (TB) can be removed from airborne infection isolation with one or two negative test results.
The Xpert MTB/RIF test is a nucleic acid amplification test that can test specifically for the mycobacterial DNA that causes TB. The test can detect TB even when the smear test appears negative.
The FDA’s expanded approval was supported by a large clinical study that demonstrated the ability of one or two consecutive negative MTB/RIF test results to correctly identify patients who would also test negative for the TB bacteria by AFB smearing testing of the sputum. The study showed that a single negative MTB/RIF test result predicted the absence of MTB-complex on AFB smears 99.7% of the time. Also, two consecutive negative MTB/RIF test results predicted the absence of bacteria 100% of the time.
The Centers for Disease Control and Prevention (CDC) has warned that the MTB/RIF test may not detect all patients with active TB disease. Healthcare workers are to continue following the current CDC guidelines to collect consecutive sputum specimens for TB culture testing, even with negative MTB/RIF test results.
For more information visit FDA.gov.