Implementation of new tools for multidrug-resistant tuberculosis detection and control. (December 2016)

• Record Type: Journal Article
• Authors: Warren, Robin M.
• Is Part Of: International journal of mycobacteriology. Volume 5 (2016:Dec.)Supplement 1
• Page Start: S67
• Publication Date: 2016-12
• Subjects: Tuberculosis -- Drug resistance -- Diagnosis; Mycobacteria -- Periodicals; Mycobacterial diseases -- Periodicals; Mycobacteriaceae; Mycobacteria; Electronic journals; Periodicals; 579.374
• DOI: 10.1016/j.ijmyco.2016.08.014
• Languages: English
• ISSNs: 2212-5531

Abstract

Abstract: Contrary to classical dogma, molecular epidemiological studies and mathematical modeling clearly show that the global drug-resistant tuberculosis (TB) epidemic is driven by transmission. Furthermore, there is mounting evidence demonstrating that amplification of resistance occurs during treatment, possibly as a result of insufficient active drugs being administered. To control the drug-resistant TB epidemic, it will be essential to implement new, rapid, and highly sensitive and specific diagnostic methods to decrease the diagnostic delay associated with culture-based testing. To date, three molecular-based diagnostic tests have been endorsed by the World Health Organization: MTBDR plus (Hain Lifescience, Nehren, Germany) Xpert MTB/RIF (Cepheid, Sunnyvale, United States) MTBDR sl (Hain Lifescience, Nehren, Germany). Implementation of the MTBDR plus assay reduced the laboratory turnaround time from 55 days to 27 days. This was further reduced to 1 day with the implementation of the Xpert MTB/RIF assay. However, time to initiation of multidrug-resistant TB (MDR-TB) treatment was not significantly reduced, remaining at approximately 17 days from receipt of drug-susceptibility testing (DST) results. In an attempt to reduce the time to initiation of MDR-TB treatment, some guidelines have recommended initiating MDR-TB treatment based on the diagnosis of rifampicin resistance alone (within 5 days). However, this implies treating MDR-TB blindly until routine culture-based DST results are available (mean, 54 days). This strategy may be highly effective in countries where second-line treatment has only recently been introduced, but may have significant consequences for patients with resistance beyond MDR-TB sensu stricto . Implementation of the MTBDR sl assay promises to reduce the time for DST for fluoroquinolones and second-line injectable drugs. These tests will form the foundation for DST for the implementation of the recently recommended shortened MDR-TB regimen. The impact of the implementation of these tests on treatment outcome using either the standard or shortened MDR-TB remains to be determined.