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Latent tuberculosis infection (LTBI) is characterised by the presence of immune responses to previously acquired Mycobacterium tuberculosis infection without clinical evidence of active tuberculosis (TB). Here we report evidence-based guidelines from the World Health Organization for a public health approach to the management of LTBI in high risk individuals in countries with high or middle upper income and TB incidence of, Guidelines on LTBI for low TB incidence countries – essential element of the @WHO #EndTB strategy and TB elimination http://ow.ly/RW8xn

Simultaneous use of genotypic and phenotypic diagnostic tools for detection of rifampicin (RIF) susceptibility may yield discrepant results.To measure the discordance between the RIF-susceptibility results by Xpert MTB/RIF and Mycobacterium Growth Indicator Tube (MGIT), to evaluate if application of both tests to the same sample affects the discrepancy, and to evaluate treatment outcome in patients with the discordant strains.Sputa from patients with tuberculosis managed in the penitentiary system of Azerbaijan during 2011-2015 were examined for RIF susceptibility using Xpert MTB/RIF and MGIT. Strains with discrepant results were sequenced.Of 532 patients included, 6.2% had discordant RIF-susceptibility results. No significant association of the discordant RIF-susceptibility results with application of both tests on one sample versus sequential samples was found. L511P mutation accounted significantly (p = 0.006) for the discrepancy among those RIF resistant on Xpert MTB/RIF, but sensitive on MGIT. No significant association was identified between the outcomes of treatment with the first- or second-line drugs and the presence of any mutation.The Xpert MTB/RIF and MGIT testing may be used in sequential sputum samples without increase in the RIF-susceptibility discordance rate. L511P mutation significantly accounts for discordant RIF-susceptibility results, but its clinical relevance may be low.

XpertMTB/RIF is a rapid molecular diagnostic tool detecting MTB and RIF-susceptibility within two hours. However, indeterminate RIF-susceptibility results occur and cause uncertainty about clinical judgment. Objective: To evaluate the level of indeterminate RIF-susceptibility results by XpertMTB/RIF, to assess the RIF-susceptibility of such strains and to determine the method that should be used for reference. Methods: Sputum from patients with TB diagnosed in Azerbaijan prisons during 2013-2015 were directly examined by XpertMTB/RIF. Strains with indeterminate RIF-susceptibility results were examined with MGIT-based DST and rpoB sequencing. For comparison, frozen MGIT cultures collected from other TB patients at diagnosis during 2010-2012 were revived and examined with XpertMTB/RIF retrospectively. Results: Of 275 samples examined with XpertMTB/RIF directly and of 232 revived cultures examined retrospectively, 8(2.9%) and 0 had indeterminate RIF-susceptibility results, respectively (p=0.009). MGIT results indicated full concordance with sequencing among the samples showing indeterminate RIF-susceptibility results by XpertMTB/RIF. Conclusion: The indeterminate RIF-susceptibility detected on sputum samples directly by XpertMTB/RIF is significant. However, this drawback may be resolved with the use of Xpert MTB/RIF on cultures. MGIT may be referred to in cases of indeterminate RIF-susceptibility by XpertMTB/RIF.