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Sputum culture reversion after conversion is an indicator of tuberculosis (TB) treatment failure. We analyze data from the endTB multi-country prospective observational cohort (NCT03259269) to estimate the frequency (primary endpoint) among individuals receiving a longer (18-to-20 month) regimen for multidrug- or rifampicin-resistant (MDR/RR) TB who experienced culture conversion. We also conduct Cox proportional hazard regression analyses to identify factors associated with reversion, including comorbidities, previous treatment, cavitary disease at conversion, low body mass index (BMI) at conversion, time to conversion, and number of likely-effective drugs. Of 1,286 patients, 54 (4.2%) experienced reversion, a median of 173 days (97-306) after conversion. Cavitary disease, BMI < 18.5, hepatitis C, prior treatment with second-line drugs, and longer time to initial culture conversion were positively associated with reversion. Reversion was uncommon. Those with cavitary disease, low BMI, hepatitis C, prior treatment with second-line drugs, and in whom culture conversion is delayed may benefit from close monitoring following conversion., (© 2024. The Author(s).)

Among 43 pregnant women receiving multidrug-resistant/rifampicin-resistant tuberculosis (MDR/RR-TB) treatment with bedaquiline and/or delamanid, 98% had favorable treatment outcomes. Of 31 continued pregnancies, 81% had live births with no reported malformations, and 68% of neonates had normal birth weights. Effective MDR/RR-TB treatment during pregnancy can improve maternal outcomes without harming neonates., Competing Interests: Potential conflicts of interest. C. D. M. is a member of the Akagera Scientific Advisory Board (for development of lipid-based, nanoparticle delivery of anti-TB drugs; 1 payment made to Partners In Health as honorarium for this work). M. L. R. declares 5% of time spent on a National Institute of Allergy and Infectious Disease–sponsored grant (an observational study of multidrug-resistant TB treatment regimens) and 5% of time spent as an expert consultant on operational research for a World Health Organization EURO project. All remaining authors: No reported conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Rationale: Current recommendations for the treatment of rifampicin- and multidrug-resistant tuberculosis include bedaquiline (BDQ) used for 6 months or longer. Evidence is needed to inform the optimal duration of BDQ. Objectives: We emulated a target trial to estimate the effect of three BDQ duration treatment strategies (6, 7-11, and ⩾12 mo) on the probability of successful treatment among patients receiving a longer individualized regimen for multidrug-resistant tuberculosis. Methods: To estimate the probability of successful treatment, we implemented a three-step approach comprising cloning, censoring, and inverse probability weighting. Measurements and Main Results: The 1,468 eligible individuals received a median of 4 (interquartile range, 4-5) likely effective drugs. In 87.1% and 77.7% of participants, this included linezolid and clofazimine, respectively. The adjusted probability of successful treatment was 0.85 (95% confidence interval [CI], 0.81-0.88) for 6 months of BDQ, 0.77 (95% CI, 0.73-0.81) for 7-11 months, and 0.86 (95% CI, 0.83-0.88) for ⩾12 months. Compared with 6 months of BDQ, the ratio of treatment success was 0.91 (95% CI, 0.85-0.96) for 7-11 months and 1.01 (95% CI, 0.96-1.06) for ⩾12 months. Naive analyses that did not account for bias revealed a higher probability of successful treatment with ⩾12 months (ratio, 1.09 [95% CI, 1.05-1.14]). Conclusions: BDQ use beyond 6 months did not increase the probability of successful treatment among patients receiving longer regimens that commonly included new and repurposed drugs. When not properly accounted for, immortal person-time bias can influence estimates of the effects of treatment duration. Future analyses should explore the effect of treatment duration of BDQ and other drugs in subgroups with advanced disease and/or receiving less potent regimens.

Background: Concomitant use of bedaquiline (Bdq) and delamanid (Dlm) for multi-drug/rifampicin resistant tuberculosis (MDR/RR-TB) has raised concerns about a potentially poor risk-benefit ratio. Yet this combination is an important alternative for patients infected with strains of TB with complex drug resistance profiles or who cannot tolerate other therapies. We assessed safety and treatment outcomes of MDR/RR-TB patients receiving concomitant Bdq and Dlm, along with other second-line anti-TB drugs., Methods: We conducted a multi-centric, prospective observational cohort study across 14 countries among patients receiving concomitant Bdq-Dlm treatment. Patients were recruited between April 2015 and September 2018 and were followed until the end of treatment. All serious adverse events and adverse events of special interest (AESI), leading to a treatment change, or judged significant by a clinician, were systematically monitored and documented., Results: Overall, 472 patients received Bdq and Dlm concomitantly. A large majority also received linezolid (89.6%) and clofazimine (84.5%). Nearly all (90.3%) had extensive disease; most (74.2%) had resistance to fluoroquinolones. The most common AESI were peripheral neuropathy (134, 28.4%) and electrolyte depletion (94, 19.9%). Acute kidney injury and myelosuppression were seen in 40 (8.5%) and 24 (5.1%) of patients, respectively. QT prolongation occurred in 7 patients (1.5%). Overall, 78.0% (358/458) had successful treatment outcomes, 8.9% died, and 7.2% experienced treatment failure., Conclusions: Concomitant use of Bdq and Dlm, along with linezolid and clofazimine, is safe and effective for MDR/RR-TB patients with extensive disease. Using these drugs concomitantly is a good therapeutic option for patients with resistance to many anti-TB drugs., Competing Interests: Potential conflicts of interest. Bedaquiline donations made from Janssen to the Global Drug Facility were used for patients in the endTB observational study. Donations of delamanid from Otsuka were used for initial patients enrolled in the endTB Observational Study. The companies from which drug donations were received did not have any role on the study design, data analyses, data interpretation or manuscript writing. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2022. Published by Oxford University Press for the Infectious Diseases Society of America.)

Background: Safety of treatment for multidrug-resistant tuberculosis (MDR/RR-TB) can be an obstacle to treatment completion. Evaluate safety of longer MDR/RR-TB regimens containing bedaquiline and/or delamanid., Methods: Multicentre (16 countries), prospective, observational study reporting incidence and frequency of clinically relevant adverse events of special interest (AESIs) among patients who received MDR/RR-TB treatment containing bedaquiline and/or delamanid. The AESIs were defined a priori as important events caused by bedaquiline, delamanid, linezolid, injectables, and other commonly used drugs. Occurrence of these events was also reported by exposure to the likely causative agent., Results: Among 2296 patients, the most common clinically relevant AESIs were peripheral neuropathy (26.4%), electrolyte depletion (26.0%), and hearing loss (13.2%) with an incidence per 1000 person months of treatment, 1000 person-months of treatment 21.5 (95% confidence interval [CI]: 19.8-23.2), 20.7 (95% CI: 19.1-22.4), and 9.7 (95% CI: 8.6-10.8), respectively. QT interval was prolonged in 2.7% or 1.8 (95% CI: 1.4-2.3)/1000 person-months of treatment. Patients receiving injectables (N = 925) and linezolid (N = 1826) were most likely to experience events during exposure. Hearing loss, acute renal failure, or electrolyte depletion occurred in 36.8% or 72.8 (95% CI: 66.0-80.0) times/1000 person-months of injectable drug exposure. Peripheral neuropathy, optic neuritis, and/or myelosuppression occurred in 27.8% or 22.8 (95% CI: 20.9-24.8) times/1000 patient-months of linezolid exposure., Conclusions: AEs often related to linezolid and injectable drugs were more common than those frequently attributed to bedaquiline and delamanid. MDR-TB treatment monitoring and drug durations should reflect expected safety profiles of drug combinations., Clinical Trials Registration: NCT02754765., Competing Interests: Potential conflicts of interest. C. D. M. is a member of the Akagera Scientific Advisory Board for development of lipid-based, nanoparticle delivery of anti-tuberculosis (TB) drugs (one payment was made to Partners In Health as honorarium for this work). M. R. declared 5% of time spent on a National Institute of Allergy and Infectious Disease–sponsored grant, an observational study of multidrug-resistant TB treatment regimens, and 5% of time spent as an expert consultant on operational research for a World Health Organization EURO project S. P. reports being a subinvestigator on the Pragmatic Clinical Trial for a More Effective Concise and Less Toxic MDR-TB Treatment Regimen(s) (TB-PRACTECAL) trial, sponsored by Médecins Sans Frontières, as an employee of the Tuberculosis & HIV Investigative Network. All remaining authors: No reported conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2022. Published by Oxford University Press for the Infectious Diseases Society of America.)

Background: Recent World Health Organization guidance on drug-resistant tuberculosis treatment de-prioritised injectable agents, in use for decades, and endorsed all-oral longer regimens. However, questions remain about the role of the injectable agent, particularly in the context of regimens using new and repurposed drugs. We compared the effectiveness of an injectable-containing regimen to that of an all-oral regimen among patients with drug-resistant tuberculosis who received bedaquiline and/or delamanid as part of their multidrug regimen., Methods: Patients with a positive baseline culture were included. 6-month culture conversion was defined as two consecutive negative cultures collected >15 days apart. We derived predicted probabilities of culture conversion and relative risk using marginal standardisation methods., Results: Culture conversion was observed in 83.8% (526 out of 628) of patients receiving an all-oral regimen and 85.5% (425 out of 497) of those receiving an injectable-containing regimen. The adjusted relative risk comparing injectable-containing regimens to all-oral regimens was 0.96 (95% CI 0.88-1.04). We found very weak evidence of effect modification by HIV status: among patients living with HIV, there was a small increase in the frequency of conversion among those receiving an injectable-containing regimen, relative to an all-oral regimen, which was not apparent in HIV-negative patients., Conclusions: Among individuals receiving bedaquiline and/or delamanid as part of a multidrug regimen for drug-resistant tuberculosis, there was no significant difference between those who received an injectable and those who did not regarding culture conversion within 6 months. The potential contribution of injectable agents in the treatment of drug-resistant tuberculosis among those who were HIV positive requires further study., Competing Interests: Conflict of interest: P.Y. Khan reports grants from Unitaid, during the conduct of the study; other (study drug donations coordinated by the endTB Consortium) from Otsuka Pharamceutical and Janssen, outside the submitted work. Conflict of interest: M.F. Franke reports grants from Unitaid, during the conduct of the study. Conflict of interest: C. Hewison reports grants from Unitaid, during the conduct of the study. Conflict of interest: K.J. Seung reports grants from Unitaid, during the conduct of the study. Conflict of interest: H. Huerga reports grants from Unitaid, during the conduct of the study. Conflict of interest: S. Atwood has nothing to disclose. Conflict of interest: S. Ahmed reports grants from Unitaid, during the conduct of the study; other (study drug donations coordinated by the endTB Consortium) from Otsuka Pharamceutical and Janssen Pharmaceutical, outside the submitted work. Conflict of interest: M. Khan has nothing to disclose. Conflict of interest: T. Sultana has nothing to disclose. Conflict of interest: M. Manzur-ul-Alam has nothing to disclose. Conflict of interest: L.N.Q. Vo reports grants and non-financial support (drugs/equipment) from Unitaid via IRD Global during the conduct of the study. Conflict of interest: L. Lecca has nothing to disclose. Conflict of interest: K. Yae has nothing to disclose. Conflict of interest: S. Kozhabekov has nothing to disclose. Conflict of interest: M. Tamirat has nothing to disclose. Conflict of interest: A. Gelin has nothing to disclose. Conflict of interest: S.C. Vilbrun has nothing to disclose. Conflict of interest: M. Kikvidze has nothing to disclose. Conflict of interest: J. Faqirzai has nothing to disclose. Conflict of interest: A. Kadyrov has nothing to disclose. Conflict of interest: A. Skrahina has nothing to disclose. Conflict of interest: A. Mesic has nothing to disclose. Conflict of interest: N. Avagyan has nothing to disclose. Conflict of interest: M. Bastard reports grants from Unitaid, during the conduct of the study. Conflict of interest: M.L. Rich reports grants from Unitaid, during the conduct of the study; personal fees for consultancy from World Health Organization, other (study drug donations coordinated by the endTB Consortium) from Otsuka Pharamceutical and Janssen, outside the submitted work. Conflict of interest: U. Khan reports grants from Unitaid, during the conduct of the study; other (study drug donations coordinated by the endTB Consortium) from Otsuka Pharamceutical and Janssen, outside the submitted work. Conflict of interest: C.D. Mitnick reports a grant from Unitaid to fund the study and that the endTB Consortium coordinated donations of delamanid (Otsuka Pharmaceutical) and bedaquiline (Janssen) to be used for treatment by some of the patients included in the endTB Observational Study., (Copyright ©The authors 2022. For reproduction rights and permissions contact permissions@ersnet.org.)

Rifampicin-resistant/multidrug-resistant (RR/MDR) and extensively drug-resistant (XDR) strains of M. tuberculosis (TB) are serious public health problem in Kazakhstan. In 2012 and 2013, stringent regulatory authorities approved the first new TB drugs in fifty years, bedaquiline and delamanid, offering hope for more effective and less toxic MDR-TB treatment. The endTB Observational Study is a multi-country study that enrolled patients receiving a bedaquiline- or delamanid-containing regimen for RR/MDR-TB between 01 April 2015 and 30 September 2018. In Kazakhstan, 675 patients participated in the study; all had at least 6-months or longer of follow-up after the start of treatment. The present analysis focuses on endTB Observational Study patients living in Kazakhstan who had a positive baseline sputum culture (220 patients) and initiated a bedaquiline- or delamanid-containing regimen between February 1, 2016 and March 31, 2018. Of them, 195 (89%) of patients experienced culture conversion within six months., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Rationale: Bedaquiline and delamanid offer the possibility of more effective and less toxic treatment for multidrug-resistant (MDR) tuberculosis (TB). With this treatment, however, some patients remain at high risk for an unfavorable treatment outcome. The endTB Observational Study is the largest multicountry cohort of patients with rifampin-resistant TB or MDR-TB treated in routine care with delamanid- and/or bedaquiline-containing regimens according to World Health Organization guidance. Objectives: We report the frequency of sputum culture conversion within 6 months of treatment initiation and the risk factors for nonconversion. Methods: We included patients with a positive baseline culture who initiated a first endTB regimen before April 2018. Two consecutive negative cultures collected 15 days or more apart constituted culture conversion. We used generalized mixed models to derive marginal predictions for the probability of culture conversion in key subgroups. Measurements and Main Results: A total of 1,109 patients initiated a multidrug treatment containing bedaquiline (63%), delamanid (27%), or both (10%). Of these, 939 (85%) experienced culture conversion within 6 months. In adjusted analyses, patients with HIV had a lower probability of conversion (0.73; 95% confidence interval [CI], 0.62-0.84) than patients without HIV (0.84; 95% CI, 0.79-0.90; P  = 0.03). Patients with both cavitary disease and highly positive sputum smear had a lower probability of conversion (0.68; 95% CI, 0.57-0.79) relative to patients without either (0.89; 95% CI, 0.84-0.95; P  = 0.0004). Hepatitis C infection, diabetes mellitus or glucose intolerance, and baseline resistance were not associated with conversion. Conclusions: Frequent sputum conversion in patients with rifampin-resistant TB or MDR-TB who were treated with bedaquiline and/or delamanid underscores the need for urgent expanded access to these drugs. There is a need to optimize treatment for patients with HIV and extensive disease.

Rationale: For treatment of multidrug-resistant tuberculosis, World Health Organization (WHO) guidelines recommend four likely effective drugs plus pyrazinamide (PZA), irrespective of the likely effectiveness of PZA in an individual patient. Whether this regimen should be supplemented in the absence of likely PZA effectiveness is an open question., Objectives: The objectives of this study were to examine (1) whether individuals receiving four likely effective drugs (based on documented susceptibility or no prior exposure) experienced higher mortality during the intensive phase of treatment than those receiving five likely effective drugs and (2) whether the WHO-recommended regimen (four likely effective drugs plus PZA) may be compromised in individuals in whom PZA is not likely effective., Methods: Among 668 patients, we compared the hazard of death across regimen groups characterized by the number of likely effective drugs and whether pyrazinamide was one of the likely effective drugs., Measurements and Main Results: Relative to five likely effective drugs, regimens of four likely effective drugs and the WHO-recommended regimen used in individuals in whom PZA was not likely effective were associated with higher mortality rates (respectively, adjusted hazard ratio [HR], 2.87; 95% confidence interval [CI], 1.35-6.09 and adjusted HR, 2.76; 95% CI, 0.92-8.27). The mortality rate for a regimen of five likely effective drugs with likely effective PZA was similar to that for the regimen of five likely effective drugs without PZA (HR, 1.00; 95% CI, 0.12-8.00)., Conclusions: Mortality may be reduced by the inclusion of five likely effective drugs, including an injectable, during the intensive phase of treatment. If PZA is unlikely to be effective in an individual patient, these results suggest adding a different, likely effective drug.

The continuing spread of drug-resistant tuberculosis (TB) is one of the most urgent and difficult challenges facing global TB control. Patients who are infected with strains resistant to isoniazid and rifampicin, called multidrug-resistant (MDR) TB, are practically incurable by standard first-line treatment. In 2012, there were approximately 450,000 new cases and 170,000 deaths because of MDR-TB. Extensively drug-resistant (XDR) TB refers to MDR-TB strains that are resistant to fluoroquinolones and second-line injectable drugs. The main causes of the spread of resistant TB are weak medical systems, amplification of resistance patterns through incorrect treatment, and transmission in communities and facilities. Although patients harboring MDR and XDR strains present a formidable challenge for treatment, cure is often possible with early identification of resistance and use of a properly designed regimen. Community-based programs can improve treatment outcomes by allowing patients to be treated in their homes and addressing socioeconomic barriers to adherence., (Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.)

Background: Evidence is sparse regarding the optimal construction of regimens to treat multidrug-resistant (MDR) tuberculosis disease due to strains of Mycobacterium tuberculosis resistant to at least both isoniazid and rifampin. Given the low potency of many second-line antituberculous drugs, we hypothesized that an aggressive regimen of at least 5 likely effective drugs during the intensive phase, including a fluoroquinolone and a parenteral agent, would be associated with a reduced risk of death or treatment failure., Methods: We conducted a retrospective cohort study of patients initiating MDR tuberculosis treatment between 2000 and 2004 in Tomsk, Russian Federation. We used a multivariate Cox proportional hazards model to assess whether monthly exposure to an aggressive regimen was associated with the risk of death or treatment failure., Results: Six hundred fourteen individuals with confirmed MDR tuberculosis were eligible for analysis. On multivariable analysis that adjusted for extensively drug-resistant (XDR) tuberculosis-MDR tuberculosis isolates resistant to fluoroquinolones and parenteral agents-we found that monthly exposure to an aggressive regimen was significantly associated with a lower risk of death or treatment failure (hazard ratio, 0.52 [95% confidence interval, .29-.94]; P = .030)., Conclusions: Receipt of an aggressive treatment regimen was a robust predictor of decreased risk of death or failure during MDR tuberculosis treatment. These findings further support the use of this regimen definition as the benchmark for the standard of care of MDR tuberculosis patients and should be used as the basis for evaluating novel therapies., (© The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Rationale: A better understanding of the composition of optimal treatment regimens for multidrug-resistant tuberculosis (MDR-TB) is essential for expanding universal access to effective treatment and for developing new therapies for MDR-TB. Analysis of observational data may inform the definition of an optimized regimen., Objectives: This study assessed the impact of an aggressive regimen-one containing at least five likely effective drugs, including a fluoroquinolone and injectable-on treatment outcomes in a large MDR-TB patient cohort., Methods: This was a retrospective cohort study of patients treated in a national outpatient program in Peru between 1999 and 2002. We examined the association between receiving an aggressive regimen and the rate of death., Measurements and Main Results: In total, 669 patients were treated with individualized regimens for laboratory-confirmed MDR-TB. Isolates were resistant to a mean of 5.4 (SD 1.7) drugs. Cure or completion was achieved in 66.1% (442) of patients; death occurred in 20.8% (139). Patients who received an aggressive regimen were less likely to die (crude hazard ratio [HR]: 0.62; 95% CI: 0.44,0.89), compared to those who did not receive such a regimen. This association held in analyses adjusted for comorbidities and indicators of severity (adjusted HR: 0.63; 95% CI: 0.43,0.93)., Conclusions: The aggressive regimen is a robust predictor of MDR-TB treatment outcome. TB policy makers and program directors should consider this standard as they design and implement regimens for patients with drug-resistant disease. Furthermore, the aggressive regimen should be considered the standard background regimen when designing randomized trials of treatment for drug-resistant TB.

Background: Mycobacterium tuberculosis strains that cause untreatable drug-resistant disease are a threat worldwide. We describe the treatment, management, and outcomes of patients with extensively drug-resistant tuberculosis in Tomsk, Russia., Methods: We undertook a retrospective cohort study of 608 patients with multidrug resistant tuberculosis who had treatment in civilian or prison services, between Sept 10, 2000, and Nov 1, 2004, according to the treatment strategy recommended by WHO. Clinical characteristics, management practices, and treatment outcomes of patients with extensively drug-resistant (XDR) tuberculosis and non-extensively drug-resistant (non-XDR) tuberculosis are described. The main outcome was the frequency of poor and favourable outcomes at the end of treatment., Findings: Of 608 patients with multidrug resistant tuberculosis, 29 (4.8%) patients had baseline XDR tuberculosis. Treatment failure was more common in patients with XDR tuberculosis than in those with non-XDR tuberculosis (31%vs 8.5%, p=0.0008). 48.3% of patients with XDR tuberculosis and 66.7% of patients with non-XDR tuberculosis had treatment cure or completion (p=0.04). The frequency and management of adverse events did not differ between patients with XDR and non-XDR tuberculosis., Interpretation: The chronic features of tuberculosis in these patients suggest that extensively drug-resistant tuberculosis may be acquired through previous treatments that include second-line drugs. Aggressive management of this infectious disease is feasible and can prevent high mortality rates and further transmission of drug-resistant strains of Mycobacterium tuberculosis.

Evidence of successful management of multidrug-resistant tuberculosis (MDRTB) is mainly generated from referral hospitals in high-income countries. We evaluate the management of MDRTB in 5 resource-limited countries: Estonia, Latvia, Peru, the Philippines, and the Russian Federation. All projects were approved by the Green Light Committee for access to quality-assured second-line drugs provided at reduced price for MDRTB management. Of 1047 MDRTB patients evaluated, 119 (11%) were new, and 928 (89%) had received treatment previously. More than 50% of previously treated patients had received both first- and second-line drugs, and 65% of all patients had infections that were resistant to both first- and second-line drugs. Treatment was successful in 70% of all patients, but success rate was higher among new (77%) than among previously treated patients (69%). In resource-limited settings, treatment of MDRTB provided through, or in collaboration with, national TB programs can yield results similar to those from wealthier settings.

Multidrug-resistant tuberculosis (MDR-TB) presents an increasing threat to global tuberculosis control. Many crucial management issues in MDR-TB treatment remain unanswered. We reviewed the existing scientific research on MDR-TB treatment, which consists entirely of retrospective cohort studies. Although direct comparisons of these studies are impossible, some insights can be gained: MDR-TB can and should be addressed therapeutically in resource-poor settings; starting of treatment early is crucial; aggressive treatment regimens and high-end dosing are recommended given the lower potency of second-line antituberculosis drugs; and strategies to improve treatment adherence, such as directly observed therapy, should be used. Opportunities to treat MDR-TB in developing countries are now possible through the Global Fund to Fight AIDS, TB, and Malaria, and the Green Light Committee for Access to Second-line Anti-tuberculosis Drugs. As treatment of MDR-TB becomes increasingly available in resource-poor areas, where it is needed most, further clinical and operational research is urgently needed to guide clinicians in the management of this disease.

This review examines the paradigm shift around multidrug-resistant tuberculosis (MDR-TB). This shift has centered largely on the activities of institutions participating in the World Health Organization's Working Group on DOTS-Plus for MDR-TB. We review the important milestones since 1995, namely, the emergence of new evidence, the construction of new mechanisms, and the building of consensus to support new policy guidelines. This paper offers a case study of the construction of a model of good global governance that--if the opportunity is taken--can improve access to effective TB care through improving and helping to expand the WHO-recommended DOTS strategy.