News Medical (01.22.2014)
Aids Weekly Plus
News-Medical.net reported on a second systematic review of the Xpert® MTB/RIF TB test, which is endorsed by the World Health Organization (WHO). WHO commissioned this updated Cochrane Review as part of the process to update the policy on the use of the test. Xpert® MTB/RIF can detect TB and whether the strain of TB is resistant to rifampicin, a first-line anti-TB drug. The test is automated and detects TB bacteria at low concentrations without the use of expert staff or an advanced laboratory.
This updated review included new studies published since the original review of January 2013. The researchers led by Karen Steingart, an editor with the Cochrane Infectious Diseases Group at the Liverpool School of Tropical Medicine, analyzed data from an additional nine studies along with the 18 studies from the original review. The studies were conducted in low- or middle-income countries and involved approximately 9,500 people.
Results showed the Xpert® MTB/RIF to be accurate for TB detection with 89 percent sensitivity and 99 percent specificity. The test also had 95 percent sensitivity and 98 percent specificity for detecting rifampicin resistance. Its accuracy seemed to be the same with HIV-positive and HIV-negative individuals. Xpert® MTB/RIF proved to be more accurate than the smear microscopy test, which requires high concentrations of bacteria, expert staff, and an advanced laboratory, and does not detect drug resistance.
The full report, “Xpert® MTB/RIF Assay for Pulmonary Tuberculosis and Rifampicin Resistance in Adults,” is published online in the Cochrane Library (2014; doi: 10.1002/14651858.CD009593.pub3).