Researchers from the Cochrane Infectious Diseases Group, hosted at LSTM, have conducted an independent review to examine the diagnostic accuracy of the GenoType® MTBDRsl assay for the detection of resistance to second-line anti-tuberculosis drugs.
While there are a number of different drugs available to people suffering from tuberculosis (TB), resistance to these drugs is a growing problem. People suffering from a drug-resistant strain of TB are more likely to die from the disease, and require treatment with what are described as “second-line” drugs. These drugs can cause more side effects and must be taken for longer.
A rapid and accurate test that could identify people with resistant TB, including a type of TB that is resistant to almost all anti-TB drugs, called XDR-TB, is likely to improve patient care and reduce the spread of drug-resistant TB.
GenoType® MTBDRsl is the only rapid test that detects resistance to second-line fluoroquinolone (FQ) drugs and second-line injectable drugs (SLID) as well as detecting XDR-TB. MTBDRsl can be performed on TB bacteria grown from sputum, which is called indirect testing and can take a long time, or can be performed immediately on sputum, which is called direct testing.
The authors reviewed the results from 21 studies, 14 of which reported the accuracy of MTBDRsl with direct testing, five of which looked at indirect testing and two of which looked at both.
By indirect testing, the test detected 83% of people with FQ resistance and rarely gave a positive result for people without resistance. In a population of 1000 people, where 170 have FQ resistance, MTBDRsl will correctly identify 141 people with FQ resistance and miss 29 people.
Of the 830 people who do not have FQ resistance, the test will correctly classify 811 people as not having FQ resistance and misclassify 19 people as having resistance. By direct testing, the test detected 85% of people with FQ resistance and rarely gave a positive result for people without resistance.
By indirect testing, the test detected 77% of people with SLID resistance and rarely gave a positive result for people without resistance. In a population of 1000 people, where 230 have SLID resistance, MTBDRsl will correctly identify 177 people with SLID resistance and miss 53 people.
Of the 770 people who do not have SLID resistance, the test will correctly classify 766 people as not having SLID resistance and misclassify four people as having resistance. By direct testing, the test detected 94% of people with SLID resistance and rarely gave a positive result for people without resistance.
By indirect testing, the test detected 71% of people with XDR-TB and rarely gave a positive result for people without XDR-TB. In a population of 1000 people, where 80 have XDR-TB, MTBDRsl will correctly identify 57 people with XDR-TB and miss 23 people. In this same population of 1000 people, where 920 do not have XDR-TB, the test will correctly classify 909 people as not having XDR-TB and misclassify 11 people as having XDR-TB. There was insufficient evidence recorded to determine the accuracy of MTBDRsl by direct testing for XDR-TB.
Dr Grant Theron from The University of Cape Town, lead author of the review said: “Our review shows that in adults with TB, a positive result for second-line drugs, either fluoroquinolone or injectable, or XDR-TB can be treated with confidence. However, given that a number of people tested negative while having a resistant strain, clinicians may still want to carry out conventional testing in some cases.”
Gill Wareing | EurekAlert!
Researchers identify cause of hereditary skeletal muscle disorder
22.02.2017 | Klinikum der Universität München
Second cause of hidden hearing loss identified
20.02.2017 | Michigan Medicine - University of Michigan
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
22.02.2017 | Power and Electrical Engineering
22.02.2017 | Life Sciences
22.02.2017 | Physics and Astronomy