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Background: Although phenotypic drug susceptibility testing (DST) is endorsed as the standard for secondline drug testing of Mycobacterium tuberculosis, it is slow and laborious. Methods: We evaluated the accuracy of two faster, easier methodologies that provide results for multiple drugs: a genotypic TaqMan® Array Card (TAC) and the Sensititrew MYCOTBTM plate. Both methods were tested at three central laboratories in Bangladesh, Tanzania, and Thailand with 212 multidrug-resistant tuberculosis (MDR-TB) isolates and compared with the laboratories' phenotypic method in use. Results: The overall accuracy for ethambutol, streptomycin, amikacin, kanamycin, ofloxacin, and moxifloxacin vs. the phenotypic standard was 87% for TAC (range 70-99) and 88% for the MYCOTB plate (range 76-98). To adjudicate discordances, we re-defined the standard as the consensus of the three methods, against which the TAC and MYCOTB plate yielded 94-95% accuracy, while the phenotypic result yielded 93%. Some isolates with genotypic mutations and high minimum inhibitory concentration (MIC) were phenotypically susceptible, and some isolates without mutations and low MIC were phenotypically resistant, questioning the phenotypic standard. Conclusions: In our view, the TAC, the MYCOTB plate, and the conventional phenotypic method have similar performance for second-line drugs; however, the former methods offer speed, throughput, and quantitative DST information.

HUMAN IMMUNODEFICIENCY VIRUS (HIV) is more common in the Irkutsk oblast of Eastern Siberia than all other regions in the Russian Federation.1 HIV positivity has been estimated to be as high as 57% among randomly sampled patients with injection drug use (IDU) in Irkutsk City.2 Recent co-prevalence surveillance suggests that nearly one in four new tuberculosis (TB) patients is HIV-infected in Irkutsk.3 Annual HIV-TB incidence has increased from approximately 5 per 100 000 population in 2007 to 26/ 100 000 in 2014.3 Despite the growing HIV-TB burden in Irkutsk, integration of HIV and TB services has been slow; for example, TB physicians are restricted from prescribing antiretroviral therapy (ART).4 Multidrug-resistant TB (MDR-TB, defined as resistance to at least isoniazid [INH] and rifampin [RMP]) also complicates HIV-TB treatment in Irkutsk. In a previous retrospective examination of Mycobacterium tuberculosis isolates from the region, 25% of patients without previous treatment had MDR-TB.5 In Tomsk, Siberia, through a recent multidisciplinary effort to individualize MDR-TB treatment, relatively high rates of favorable treatment outcomes were reported.6 However, these patients were largely non-HIV-infected, and anti-tuberculosis treatment had been applied in an algorithmic approach based on expanded drug susceptibility testing (DST) results. The potential utility of such an approach within the HIV-infected population of Irkutsk has not been studied. We enrolled HIV-infected patients presenting for anti-tuberculosis treatment to examine M. tuberculosis drug resistance and patterns of anti-tuberculosis drug and ART prescription in relation to outcomes of anti-tuberculosis treatment. An interim analysis found that ART initiation was less frequent than anticipated. We reoriented the study to understand this observation, describe the interventions to improve ART initiation, and report on short-term in-patient TB outcomes.