Treatment outcomes 24 months after initiating short, all-oral bedaquiline-containing or injectable-containing rifampicin-resistant tuberculosis treatment regimens in South Africa: a retrospective cohort study

A non-randomized pragmatic historically controlled trial evaluating the effectiveness and safety of a bedaquiline or a linezolid-based short regimen for rifampicin-resistant tuberculosis

BACKGROUND

Short all-oral regimens for Rifampicin-resistant tuberculosis (ShORRT) have been a turning point in the treatment of drug-resistant tuberculosis. Despite this, access to drugs, stockouts, or adverse effects may limit the use of the recommended regimens.

METHODS

Pragmatic non-randomized trial evaluating the efficacy and safety of a ShORRT strategy for the treatment of rifampicin-resistant Tuberculosis (RR-TB) at the Hospital Nossa Senhora da Paz (Angola). The strategy assigned participants to receive a bedaquiline (BDQ) or a linezolid-based (LZF) regimen supplemented with levofloxacin, clofazimine, and cycloserine for up to 9 months.

RESULTS

One hundred and twenty-one participants with pulmonary RR-TB were treated with the ShORRT strategy; 69 received the bedaquiline- and 52 the linezolid-based regimen. Overall, 98 (81%) participants had successful treatment outcomes, which was significantly higher compared to a 20-month historical injectable-based regimen (successful outcome rate including cure and treatment completed: 53.7%) (p < 0.001). No significant differences between treatment success rates (85.5% vs. 75.0%), treatment failure (0.0% vs. 1.9%), death (5.8% vs. 13.5%), or lost to follow-up (LTFU) (8.7% vs. 9.6%) were seen between the BDQ and the LZF-based regimen. Globally, 72 adverse events (AE) occurred in 36 (29.7%) participants. Eighteen (14.9%) of these were grade ≥3 and were more frequently observed in those receiving the LZD-based regimen (p = 0.02).

CONCLUSION

The ShORRT strategy with a nine-month BDQ- or LZD-based regimen supports the efficacy of shorter all-oral regimens for the treatment of RR-TB and presents real-world data from schemes without bedaquiline, nitroimidazole, or injectables.

Advancing against drug-resistant tuberculosis: an extensive review, novel strategies and patent landscape

Drug-resistant tuberculosis (DR-TB) represents a pressing global health issue, leading to heightened morbidity and mortality. Despite extensive research efforts, the escalation of DR-TB cases underscores the urgent need for enhanced prevention, diagnosis, and treatment strategies. This review delves deep into the molecular and genetic origins of different types of DR-TB, highlighting recent breakthroughs in detection and diagnosis, including Rapid Diagnostic Tests like Xpert Ultra, Whole Genome Sequencing, and AI-based tools along with latest viewpoints on diagnosis and treatment of DR-TB utilizing newer and repurposed drug molecules. Special emphasis is given to the pivotal role of novel drugs and discusses updated treatment regimens endorsed by governing bodies, alongside innovative personalized drug-delivery systems such as nano-carriers, along with an analysis of relevant patents in this area. All the compiled information highlights the inherent challenges of current DR-TB treatments, discussing their complexity, potential side effects, and the socioeconomic strain they impose, particularly in under-resourced regions, emphasizing the cost-effective and accessible solutions. By offering insights, this review aims to serve as a compass for researchers, healthcare practitioners, and policymakers, emphasizing the critical need for ongoing R&D to improve treatments and broaden access to crucial TB interventions.

Drug-resistant tuberculosis: a persistent global health concern

Drug-resistant tuberculosis (TB) is estimated to cause 13% of all antimicrobial resistance-attributable deaths worldwide and is driven by both ongoing resistance acquisition and person-to-person transmission. Poor outcomes are exacerbated by late diagnosis and inadequate access to effective treatment. Advances in rapid molecular testing have recently improved the diagnosis of TB and drug resistance. Next-generation sequencing of Mycobacterium tuberculosis has increased our understanding of genetic resistance mechanisms and can now detect mutations associated with resistance phenotypes. All-oral, shorter drug regimens that can achieve high cure rates of drug-resistant TB within 6-9 months are now available and recommended but have yet to be scaled to global clinical use. Promising regimens for the prevention of drug-resistant TB among high-risk contacts are supported by early clinical trial data but final results are pending. A person-centred approach is crucial in managing drug-resistant TB to reduce the risk of poor treatment outcomes, side effects, stigma and mental health burden associated with the diagnosis. In this Review, we describe current surveillance of drug-resistant TB and the causes, risk factors and determinants of drug resistance as well as the stigma and mental health considerations associated with it. We discuss recent advances in diagnostics and drug-susceptibility testing and outline the progress in developing better treatment and preventive therapies.

Effectiveness and safety of modified fully oral 9-month treatment regimens for rifampicin-resistant tuberculosis: a prospective cohort study

BACKGROUND

In 2020, WHO guidelines prioritised the use of a standard fully oral short treatment regimen (STR) consisting of bedaquiline, levofloxacin or moxifloxacin, ethionamide, ethambutol, high-dose isoniazid, pyrazinamide, and clofazimine for the management of rifampicin-resistant tuberculosis. A high prevalence of resistance to constituent drugs precluded its widespread use by countries in the WHO European region. We evaluated three 9-month fully oral modified STRs (mSTRs) in which ethionamide, ethambutol, isoniazid, and pyrazinamide were replaced by linezolid, cycloserine, or delamanid (or a combination).

METHODS

This multicountry, prospective, single-arm, cohort study examined the effectiveness and safety of mSTRs for fluoroquinolone-susceptible, rifampicin-resistant pulmonary tuberculosis in 13 countries in the WHO European region during 2020-23. We enrolled adults and children of all ages with bacteriologically confirmed rifampicin-resistant, fluoroquinolone-susceptible pulmonary tuberculosis, and children (aged 0-18 years) with clinically diagnosed disease and a confirmed contact with rifampicin-resistant, fluoroquinolone-susceptible tuberculosis. Participants aged 6 years or older received one of two regimens: bedaquiline, linezolid, levofloxacin, clofazimine, and cycloserine; or bedaquiline, linezolid, levofloxacin, clofazimine, and delamanid. Children younger than 6 years received delamanid, linezolid, levofloxacin, and clofazimine. Participants were followed up for 12 months after successful treatment completion to detect recurrence and death. The primary outcome was the cumulative probability of not having an unsuccessful study outcome (defined as treatment failure, on-treatment loss to follow-up, death, or recurrence) before 22 months of study follow-up. The primary safety outcome was the incidence of each adverse event of interest (peripheral neuropathy, optic neuritis, myelosuppression, hepatitis, prolonged QT interval, hypokalaemia, and acute kidney injury) of grade 3 or higher severity during the treatment course.

FINDINGS

Between Aug 28, 2020 and May 26, 2021, 7272 patients were screened and 2636 were included in the treatment cohort. 1966 (74·6%) were male, 670 (25·4%) were female, and median age was 43 years (IQR 33-53). Treatment success was recorded for 2181 (82·7%) participants. The cumulative probability of not having an unsuccessful study outcome 22 months after treatment initiation was 79% (95% CI 78-81). Increasing age (adjusted hazard ratio 2·61 [95% CI 1·70-4·04] for people aged >64 years vs 35-44 years), HIV-positive status (1·53 [1·16-2·01]), presence of bilateral cavities (1·68 [1·29-2·19]), smoking history (1·34 [1·05-1·71]), baseline anaemia (1·46 [1·15-1·86]), unemployment (1·37 [1·04-1·80]), elevated baseline liver enzymes (1·40 [1·13-1·73]), and excessive alcohol use (1·47 [1·14-1·89]) were positively associated with unsuccessful study outcomes. In the safety cohort of 2813 participants who received at least one dose, 301 adverse events of interest were recorded in 252 (9·0%) participants with the most frequent being myelosuppression (139 [4·9%] participants, 157 [52·2%] events).

INTERPRETATION

The high treatment success and good safety results indicate considerable potential for the use of mSTRs in programmatic conditions, especially for individuals not eligible for the current WHO-recommended 6-month regimen and in settings with a need for alternative options.

FUNDING

The Global Fund to Fight AIDS, Tuberculosis and Malaria; United States Agency for International Development; Government of Germany; and WHO.

TRANSLATION

For the Russian translation of the abstract see Supplementary Materials section.

Clinical Features, Adverse Events and Treatment Outcomes of Multidrug/Rifampicin-resistant Tuberculosis in Children and Adolescents: An Eight-year Retrospective Cohort Study in Bandung, Indonesia

BACKGROUND

Data on childhood and adolescent multidrug/rifampicin-resistant tuberculosis (MDR/RR-TB) in Indonesia are lacking. We aimed to assess clinical features, adverse events (AEs) and treatment outcomes of childhood and adolescent MDR/RR-TB.

METHODS

A retrospective cohort study was performed in children and adolescents aged <18 years treated for MDR/RR-TB at Hasan Sadikin General Hospital in Bandung, Indonesia, between June 2016 and March 2024. Multivariable logistic regression analyses were used to calculate adjusted odds ratios (aOR) for predictors of all-cause mortality.

RESULTS

Among 84 included patients, 69 (82%) were adolescents aged 10-17 years, 54 (64%) were female, 54 (64%) were malnourished and 55 (65%) had culture-confirmed disease. Among 69 (82%) patients with known outcomes, 48 (70%) were successfully treated, 14 (20%) died (including 5 pretreatment deaths) and 7 (10%) were lost to follow-up (LTFU) (including 5 pretreatment LTFU). Predictors of all-cause mortality included shortness of breath on admission [aOR: 6.4, 95% confidence interval (CI): 1.3-49.1], high bacillary burden on Xpert MTB/RIF assay (aOR: 17.0, 95% CI: 1.6-260.5) and the presence of lung cavities on chest radiograph (aOR: 4.8, 95% CI: 1.1-23.3). Among 74 patients who initiated treatment, 39 (53%) had at least one grade 1-2 AE, and 4 (5%) had one grade 3-4 AE each, including hepatotoxicity, QT prolongation, hearing loss and rash/hyperpigmentation.

CONCLUSION

Younger children were underrepresented among those treated for MDR/RR-TB, indicating reduced access to care. Severe AEs were uncommon during MDR/RR-TB treatment. Baseline indicators of extensive disease were associated with all-cause mortality. The high proportion of pre-treatment mortality and LTFU may reflect complex patient pathways limiting access to care.

Effectiveness of bedaquiline containing all oral longer regimens in treating multidrug/rifampicin resistant tuberculosis in Pakistan

BACKGROUND

Despite the introduction of bedaquiline (Bdq) containing all-oral regimens for treating patients with rifampicin resistant/multidrug resistant tuberculosis (MDR/RR-TB) in 2019, data on its effectiveness in Pakistan, which has the fifth highest MDR-TB burden, is lacking. This study evaluates treatment outcomes and identifies factors associated with unsuccessful outcomes among MDR/RR-TB patients treated with an all-oral longer treatment regimen (LTR).

METHODS

This retrospective record review included all microbiologically confirmed pulmonary MDR/RR-TB patients treated with an all-oral LTR between August 2019 and February 2021 across nine PMDT centres in Pakistan. Sociodemographic and clinical data were retrieved from the Electronic Nominal Recording and Reporting System. Treatment outcomes, defined by WHO criteria, were analysed using SPSS and multivariate binary logistic regression to identify factors associated with unsuccessful outcomes. A p-value < 0.05 was considered statistically significant.

RESULTS

The final analysis included 644 MDR/RR-TB patients (mean age 37.9 ± 17.6 years), mostly male (53.0 %), underweight (68.0 %), with TB treatment history (66.1 %), MDR-TB (84.9 %), lung cavitation (71.0 %), and no comorbidities (86.4 %). Fluoroquinolone resistance was found in 41.9 %, 16 % had used second-line drugs, and 9.8 % had previous MDR-TB treatment. A total of 400 (62.1 %) patients were declared cured, 53 (8.2 %) treatment completed, 117 (18.2 %) died, 37 (5.7 %) lost to follow-up (LTFU), and 37 (5.7 %) treatment failures. Overall treatment success rate was 70.3 % (n = 453). In multivariate analysis, history of TB treatment (OR:1.63, 95 %CI:1.09-2.64, p = 0.023), previous SLD use (OR:2.09, 95 %CI: 1.20-3.37, p = 0.012), resistance to Z (OR:0.43, 95 %CI: 0.20-0.81, p = 0.023), and resistance to > 5 drugs (OR:3.12, 95 %CI:1.36-11.64, p = 0.013) were significantly associated with death and treatment failure. Whereas, lung cavitation had statistically significant association with LTFU (OR:2.66, 95 %CI:1.10-7.32, p = 0.045).

CONCLUSION

Treatment success rate (70.3 %) in this study fell below the WHO recommended target success rate (>90 %). Enhanced clinical management, coupled with special attention to patients exhibiting identified risk factors could improve treatment outcomes.

Clofazimine and QT prolongation in the treatment of rifampicin-resistant tuberculosis: Findings of aDSM in Taiwan

BACKGROUND

Bedaquiline, delamanid and fluoroquinolones are associated with increased QTcF. Whether clofazimine is associated with QTcF prolongation is less clear.

METHODS

All patients with rifampicin-resistant TB enrolled between May 2017 and Dec 2019 were included. ECGs were performed at baseline, month 1, month 3 and month 6 for patients treated with conventional regimens, and at additional timepoint for patients treated with bedaquiline, delamanid and short regimen. We estimated the maximum increase of QTcF and constructed cox proportional hazards models to assess factors associated with QTcF≥501ms.

RESULTS

Among 321 patients, 59 (18.4%) patients had QTcF≥501ms during a mean follow-up of 242 days (median 189, range 4-1091). The median maximum increase of QTcF was 43.4 ms (IQR 31.3-65.9) in patients treated with clofazimine. Treatment with clofazimine was significantly associated with QTcF≥501ms as compared to without clofazimine (adjusted hazards ratio (adjHR) 4.35, 95% confidence interval (CI) 2.01-9.44). Among patients not treated with bedaquiline and delamanid, those treated with clofazimine and a fluoroquinolone (adjHR 3.43, 95% CI 1.61-7.34) and those treated with clofazimine and high dose moxifloxacin (adjHR 6.54, 95% CI 2.43-17.60) had a significantly higher risk of QTcF≥501ms as compared to those treated with a fluoroquinolone without other QTcF prolonging agents. Four (1.6%) patients had documented ventricular tachycardia, in which one was Torsade de pointes. One patient was found to have sudden death during hospitalization.

CONCLUSIONS

Clofazimine was significantly associated with an increased risk of QTcF prolongation. QTcF≥501ms was potentially associated with fatal event and needed to be managed cautiously.

Survival Probability in Multidrug Resistant Pulmonary Tuberculosis Patients in a South Indian Region

Background: Drug-resistant tuberculosis is a burgeoning threat to public health requiring novel strategies to combat the infection. Although national tuberculosis elimination programs focus on improving health services, challenges in eradicating tuberculosis still exist. Factors attributing to unfavorable outcomes are unknown in Warangal district of Telangana state. Methods: This study included 296 patients diagnosed with multidrug-resistant pulmonary tuberculosis. The study participants followed up for a maximum of 20 months to determine treatment outcomes. Statistical applications of Kaplan-Meier curve and log-rank test used to find the survival probabilities in subgroups. Results: The survival of multidrug-resistant pulmonary tuberculosis patients was ascertained, in male and female patients, aged between 31 and 50 years. Resistance to rifampicin was prominent. The study found a survival rate of 76.68% and a mortality rate of 23.31%. The log-rank test revealed a significant difference in survival in subcategories with and without comorbidities (P = .03), non-adherence to treatment (P = .0001), treatment duration (P = .02), regimens (P = .01), and grading of radiograph (P = .0001). Conclusion: This study identified factors that influenced the survival probability of multidrug-resistant pulmonary tuberculosis patients, including comorbidities, weight band, non-adherence to treatment, treatment duration, regimens, and grading of radiograph. These findings emphasize the need for enhanced management strategies to improve treatment outcomes.

Clinical outcomes of multidrug-resistant tracheobronchial tuberculosis receiving anti-tuberculosis regimens containing bedaquiline or delamanid

The treatment of multidrug-resistant tracheobronchial tuberculosis poses challenges, and research investigating the efficacy of bedaquiline or delamanid as treatment for this condition is limited. This retrospective cohort study was conducted from 2017 to 2021. The study extracted data of patients with multidrug-resistant tracheobronchial tuberculosis from medical records and followed up on prognoses. Participants were divided into three groups: the bedaquiline, delamanid, and control group. Clinical outcomes and the risk factors associated with early culture conversion were analyzed. This study included 101 patients, with 32, 25, and 44 patients in the bedaquiline, delamanid, and control groups respectively. The differences in the treatment success rates among the three groups did not show statistical significance. Both the bedaquiline and delamanid groups had significantly higher culture conversion rates compared to the control after 2 or 6 months of treatment, with significantly shorter median times to culture conversion (bedaquiline group: 2 weeks, delamanid group: 2 weeks, control group: 12 weeks, P < 0.001). Treatment with bedaquiline or delamanid were identified as independent predictors of culture conversion at 2 months (bedaquiline group: aOR = 13.417, 95% CI 4.067-44.260, delamanid group: aOR = 9.333, 95% CI 2.498-34.878) or 6 months (bedaquiline group: aOR = 13.333, 95% CI 3.379-52.610, delamanid group: aOR = 5.000, 95% CI 1.357-18.426) of treatment through multivariable logistic regression analyses. The delamanid group showed better improvement in lumen stenosis compared to bedaquiline. Regimens containing bedaquiline or delamanid may accelerate the culture conversion during the early treatment phase in multidrug-resistant tracheobronchial tuberculosis, and delamanid appears to have the potential to effectively improve airway stenosis.

Treatment of Multidrug-resistant or Rifampicin-resistant Tuberculosis With an All-oral 9-month Regimen Containing Linezolid or Ethionamide in South Africa: A Retrospective Cohort Study

BACKGROUND

In 2019, the South African tuberculosis program replaced ethionamide with linezolid as part of an all-oral 9-month regimen. We evaluated treatment outcomes for patients assigned to regimens including linezolid in 2019 and ethionamide in 2017.

METHODS

This retrospective cohort study included patients treated for multidrug-resistant/rifampicin-resistant tuberculosis throughout South Africa between 1 January and 31 December 2017 and 1 January to 31 December 2019. The cohort treated with a 9-month regimen containing ethionamide for four months, was compared with a cohort treated with a 9-month regimen containing linezolid for 2 months. The regimens were otherwise identical. Inverse probability weighting of propensity scores was used to adjust for potential confounding. A log-binomial regression model was used to estimate adjusted relative risk (aRR) comparing 24-month outcomes between cohorts including treatment success, death, loss to follow up, and treatment failure. Adverse event data were available for the linezolid cohort.

FINDINGS

In total, 817 patients were included in the cohort receiving ethionamide and 4244 in the cohort receiving linezolid. No evidence for a difference was observed between linezolid and ethionamide regimens for treatment success (aRR = 0.96, 95% confidence interval [CI] .91-1.01), death (aRR = 1.01, 95% CI .87-1.17) or treatment failure (aRR = 0.87, 95% CI .44-1.75). Loss to follow-up was more common in the linezolid group, although estimates were imprecise (aRR = 1.22, 95% CI .99-1.50).

CONCLUSIONS

No significant differences in treatment success and survival were observed with substitution of linezolid for ethionamide as a part of an all-oral 9-month regimen. Linezolid is an acceptable alternative to ethionamide in this shorter regimen for treatment of multidrug-resistant/rifampicin-resistant tuberculosis.

Economic implications of novel regimens for tuberculosis treatment in three high-burden countries: a modelling analysis

BACKGROUND

With numerous trials investigating novel drug combinations to treat tuberculosis, we aimed to evaluate the extent to which future improvements in tuberculosis treatment regimens could offset potential increases in drug costs.

METHODS

In this modelling analysis, we used an ingredients-based approach to estimate prices at which novel regimens for rifampin-susceptible and rifampin-resistant tuberculosis treatment would be cost-neutral or cost-effective compared with standards of care in India, the Philippines, and South Africa. We modelled regimens meeting targets set in the WHO's 2023 Target Regimen Profiles (TRPs). Our decision-analytical model tracked cohorts of adults initiating rifampin-susceptible or rifampin-resistant tuberculosis treatment, simulating their health outcomes and costs accumulated during and following treatment under standard-of-care and novel regimen scenarios. Price thresholds included short-term cost-neutrality (considering only savings accrued during treatment), medium-term cost-neutrality (additionally considering savings from averted retreatments and secondary cases), and cost-effectiveness (incorporating willingness-to-pay for improved health outcomes).

FINDINGS

Total medium-term costs per person treated using standard-of-care regimens were estimated at US$450 (95% uncertainty interval 310-630) in India, $560 (350-860) in the Philippines, and $730 (530-1090) in South Africa for rifampin-susceptible tuberculosis (current drug costs $46) and $2100 (1590-2810) in India, $2610 (2090-3280) in the Philippines, and $3790 (3090-4630) in South Africa for rifampin-resistant tuberculosis (current drug costs $432). A rifampin-susceptible tuberculosis regimen meeting the optimal targets defined in the TRPs could be cost-neutral in the short term at drug costs of $140 (90-210) per full course in India, $230 (130-380) in the Philippines, and $280 (180-460) in South Africa. For rifampin-resistant tuberculosis, short-term cost-neutral thresholds were higher with $930 (720-1230) in India, $1180 (980-1430) in the Philippines, and $1480 (1230-1780) in South Africa. Medium-term cost-neutral prices were approximately $50-100 higher than short-term cost-neutral prices for rifampin-susceptible tuberculosis and $250-550 higher for rifampin-resistant tuberculosis. Health system cost-neutral prices that excluded patient-borne costs were 45-70% lower (rifampin-susceptible regimens) and 15-50% lower (rifampin-resistant regimens) than the cost-neutral prices that included patient costs. Cost-effective prices were substantially higher. Shorter duration was the most important driver of medium-term savings with novel regimens, followed by ease of adherence.

INTERPRETATION

Improved tuberculosis regimens, particularly shorter regimens or those that facilitate better adherence, could reduce overall costs, potentially offsetting higher prices.

FUNDING

WHO.

Relapse after treatment with standardized all-oral short regimens for rifampicin-resistant tuberculosis (RR-TB): A systematic review and meta-analysis

Background

Treatment for rifampicin-resistant tuberculosis (RR-TB) has been shortened to 12 months or less, with duration depending on the regimen used and treatment response. Treatment shortening has the potential to increase the risk of relapse, with a new episode of RR-TB after cure or completion. The proportion of relapses after standardized all-oral short (12 months or less) RR-TB regimens has not yet been systematically reviewed, which is the main objective of this review.

Methods

This is a systematic review and meta-analysis. PubMed, Web of Science and Google scholar databases were systematically investigated to identify studies published between January 2018 and November 2023. Characteristics of studies, demographic data, baseline clinical condition, resistance profile, and definitions used for relapse, failure, and end-of-treatment outcomes are summarized in tables and graphs. Pooled proportions are estimated for relapse.

Results

A total of ten studies were included in this review and meta-analysis, representing 1792 participants. Seven studies were clinical trials and two were cohorts. Five studies investigated all-oral six-month regimens composed of bedaquiline, pretomanid, and linezolid (BPaL). The remaining studies assessed other standardized all-oral short regimens, with treatment duration between 6 and 12 months. Post-treatment follow-up (PTFU) duration ranged from 6 to 30 months. The pooled proportion estimate of relapse was 2·0% (95 % CI, 1·0-3·0%) for all and BPaL-based regimens. Treatment extension due to poor treatment response was poorly documented.

Conclusion

This review showed that the proportion of relapse in RR-TB patients treated with standardized short all-oral regimens was low. The low relapse proportion is similar to what was achieved for drug-susceptible Tuberculosis patients treated with first-line rifampicin-containing regimens. However, most data came from trial settings, and in some studies the post-treatment follow-up was short. Studies of large programmatic cohorts with longer post-treatment follow-up periods are needed to confirm the low relapse rate shown in the clinical trials.

Multidrug-resistant tuberculosis: latest opinions on epidemiology, rapid diagnosis and management

PURPOSE OF REVIEW

This review addresses the escalating global challenge of multidrug-resistant tuberculosis (MDR-TB) in Sub-Saharan Africa, with a focus on its complex comorbidity with HIV/AIDS. Emphasizing the urgency of the issue, the review aims to shed light on the unique healthcare landscape shaped by the convergence of high prevalence rates and intersecting complexities with HIV/AIDS in the region.

RECENT FINDINGS

A notable increase in MDR-TB cases across Sub-Saharan Africa is attributed to challenges in timely diagnoses, treatment initiation, and patient treatment defaulting. The literature underscores the critical need for proactive measures to address diagnostic and treatment gaps associated with MDR-TB, particularly concerning its comorbidity with HIV/AIDS.

SUMMARY

To effectively manage MDR-TB and its co-morbidity with HIV/AIDS, proactive screening programs are imperative. The review highlights the necessity of active follow-up strategies to ensure treatment adherence and reduce default rates, offering evidence-based insights for improved disease management in the region.

Efficacy and safety of the all-oral bedaquiline-containing regimen as treatment for pediatric multidrug/rifampicin-resistant tuberculosis: a multicenter, retrospective, cohort study

OBJECTIVE

The study aimed to observe the efficacy and safety of an all-oral bedaquiline (BDQ)-containing regimen for pediatric multidrug/rifampicin-resistant tuberculosis (MDR/RR-TB) through a multicenter, retrospective study in China.

METHODS

In the study, pediatric patients receiving all-oral BDQ-containing regimen (BDQ group) with clinical matched control group were included, the control group received an injection-containing regimen. The treatment outcomes and the incidence of adverse events (AEs) were compared and analyzed.

RESULTS

79 pediatric patients were enrolled, including 37 cases in BDQ group and 42 cases in the control group, the median age was 12 {8-16} and 11 {9-15} in both groups respectively. Favorable treatment outcome and cure rate in BDQ group were significantly higher than those in control group (100%vs 83.3%, p 0.03; 94.6%vs 63.3%, p 0.00). Median time of sputum culture conversion in BDQ group was significantly shorter than that in the control group (4 weeks vs 8 weeks, p 0.00). The incidence of AEs in the BDQ group was significantly less than that in the control group (48.6% vs 71.4%, p 0.03). No AEs leading to treatment discontinuation of BDQ occurred.

CONCLUSIONS

The all-oral BDQ-containing regimens may be effective and safe in the Chinese pediatric population.

Multidrug-resistant tuberculosis

Tuberculosis (TB) remains the foremost cause of death by an infectious disease globally. Multidrug-resistant or rifampicin-resistant TB (MDR/RR-TB; resistance to rifampicin and isoniazid, or rifampicin alone) is a burgeoning public health challenge in several parts of the world, and especially Eastern Europe, Russia, Asia and sub-Saharan Africa. Pre-extensively drug-resistant TB (pre-XDR-TB) refers to MDR/RR-TB that is also resistant to a fluoroquinolone, and extensively drug-resistant TB (XDR-TB) isolates are additionally resistant to other key drugs such as bedaquiline and/or linezolid. Collectively, these subgroups are referred to as drug-resistant TB (DR-TB). All forms of DR-TB can be as transmissible as rifampicin-susceptible TB; however, it is more difficult to diagnose, is associated with higher mortality and morbidity, and higher rates of post-TB lung damage. The various forms of DR-TB often consume >50% of national TB budgets despite comprising <5-10% of the total TB case-load. The past decade has seen a dramatic change in the DR-TB treatment landscape with the introduction of new diagnostics and therapeutic agents. However, there is limited guidance on understanding and managing various aspects of this complex entity, including the pathogenesis, transmission, diagnosis, management and prevention of MDR-TB and XDR-TB, especially at the primary care physician level.

Travel distance to rifampicin-resistant tuberculosis treatment and its impact on loss to follow-up: the importance of continued RR-TB treatment decentralization in South Africa

BACKGROUND

Understanding why patients experience loss to follow-up (LTFU) is essential for TB control. This analysis examines the impact of travel distance to RR-TB treatment on LTFU, which has yet to be analyzed within South Africa.

METHODS

We retrospectively analyzed 1436 patients treated for RR-TB at ten South African public hospitals. We linked patients to their residential ward using data reported to NHLS and maps available from the Municipal Demarcation Board. Travel distance was calculated from each patient's ward centroid to their RR-TB treatment site using the georoute command in Stata. The relationship between LTFU and travel distance was modeled using multivariable logistic regression.

RESULTS

Among 1436 participants, 75.6% successfully completed treatment and 24.4% were LTFU. The median travel distance was 40.96 km (IQR: 17.12, 63.49). A travel distance > 60 km increased odds of LTFU by 91% (p = 0.001) when adjusting for HIV status, age, sex, education level, employment status, residential locale, treatment regimen, and treatment site.

CONCLUSION

People living in KwaZulu-Natal and Eastern Cape travel long distances to receive RR-TB care, placing them at increased risk for LTFU. Policies that bring RR-TB treatment closer to patients, such as further decentralization to PHCs, are necessary to improve RR-TB outcomes.

Association of indicators of extensive disease and rifampin-resistant tuberculosis treatment outcomes: an individual participant data meta-analysis

BACKGROUND

Indicators of extensive disease-acid fast bacilli (AFB) smear positivity and lung cavitation-have been inconsistently associated with clinical rifampin-resistant/multidrug-resistant tuberculosis (RR/MDR-TB) outcomes. We evaluated the association of these indicators with end-of-treatment outcomes.

METHODS

We did an individual participant data meta-analysis of people treated for RR/MDR-TB with longer regimens with documented AFB smear and chest radiography findings. We compared people AFB smear-negative without cavities to people: (1) smear-negative with lung cavities; (2) smear-positive without lung cavities and (3) AFB smear-positive with lung cavities. Using multivariable logistic regression accounting for demographic, treatment and clinical factors, we calculated adjusted ORs (aOR) for any unfavourable outcome (death, lost to follow-up, failure/recurrence), and mortality and treatment failure/recurrence alone.

RESULTS

We included 5596 participants; included participants significantly differed from excluded participants. Overall, 774 (13.8%) were AFB smear-negative without cavities, 647 (11.6%) only had cavities, 1424 (25.4%) were AFB smear-positive alone and 2751 (49.2%) were AFB smear-positive with cavities. The median age was 37 years (IQR: 28-47), 3580 (64%) were male and 686 (12.5%) had HIV. Compared with participants AFB smear-negative without cavities, aOR (95% CI) for any unfavourable outcome was 1.0 (0.8 to 1.4) for participants smear-negative with lung cavities, 1.2 (0.9 to 1.5) if smear-positive without cavities and 1.6 (1.3 to 2.0) if AFB smear-positive with lung cavities. Odds were only significantly increased for mortality (1.5, 95% CI 1.1 to 2.1) and failure/recurrence (2.2, 95% CI 1.5 to 3.3) among participants AFB smear-positive with lung cavities.

CONCLUSION

Only the combination of AFB smear-positivity and lung cavitation was associated with unfavourable outcomes, suggesting they may benefit from stronger regimens.

Molecular mechanisms of resistance and treatment efficacy of clofazimine and bedaquiline against Mycobacterium tuberculosis

Clofazimine (CFZ) and bedaquiline (BDQ) are currently used for the treatment of multidrug-resistant (MDR) Mycobacterium tuberculosis (Mtb) strains. In recent years, adding CFZ and BDQ to tuberculosis (TB) drug regimens against MDR Mtb strains has significantly improved treatment results, but these improvements are threatened by the emergence of MDR and extensively drug-resistant (XDR) Mtb strains. Recently, CFZ and BDQ have attracted much attention for their strong clinical efficacy, although very little is known about the mechanisms of action, drug susceptibility test (DST), resistance mechanisms, cross-resistance, and pharmacokinetics of these two drugs. In this current review, we provide recent updates on the mechanisms of action, DST, associated mutations with individual resistance and cross-resistance, clinical efficacy, and pharmacokinetics of CFZ and BDQ against Mtb strains. Presently, known mechanisms of resistance for CFZ and/or BDQ include mutations within the Rv0678, pepQ, Rv1979c, and atpE genes. The cross-resistance between CFZ and BDQ may reduce available MDR-/XDR-TB treatment options. The use of CFZ and BDQ for treatment in the setting of limited DST could allow further spread of drug resistance. The DST and resistance knowledge are urgently needed where CFZ and BDQ resistance do emerge. Therefore, an in-depth understanding of clinical efficacy, DST, cross-resistance, and pharmacokinetics for CFZ and BDQ against Mtb can provide new ideas for improving treatment outcomes, reducing mortality, preventing drug resistance, and TB transmission. Along with this, it will also help to develop rapid molecular diagnostic tools as well as novel therapeutic drugs for TB.

Serial electrocardiogram recordings revealed a high prevalence of QT interval prolongation in patients with tuberculosis receiving fluoroquinolones

BACKGROUND

Fluoroquinolones, crucial components of treatment regimens for drug-resistant tuberculosis (TB), are associated with QT interval prolongation and risks of fatal cardiac arrhythmias. However, few studies have explored dynamic changes in the QT interval in patients receiving QT-prolonging agents.

METHODS

This prospective cohort study recruited hospitalized patients with TB who received fluoroquinolones. The study investigated the variability of the QT interval by using serial electrocardiograms (ECGs) recorded four times daily. This study analyzed the accuracy of intermittent and single-lead ECG monitoring in detecting QT interval prolongation.

RESULTS

This study included 32 patients. The mean age was 68.6 ± 13.2 years. The results revealed mild-to-moderate and severe QT interval prolongation in 13 (41%) and 5 (16%) patients, respectively. The incremental yields in sensitivity of one to four daily ECG recordings were 61.0%, 26.1%, 5.6%, and 7.3% in detecting mild-to-moderate QT interval prolongation, and 66.7%, 20.0%, 6.7%, and 6.7% in detecting severe QT interval prolongation. The sensitivity levels of lead II and V5 ECGs in detecting mild-to-moderate and severe QT interval prolongation exceeded 80%, and their specificity levels exceeded 95%.

CONCLUSION

This study revealed a high prevalence of QT interval prolongation in older patients with TB who receive fluoroquinolones, particularly those with multiple cardiovascular risk factors. Sparsely intermittent ECG monitoring, the prevailing strategy in active drug safety monitoring programs, is inadequate owing to multifactorial and circadian QT interval variability. Additional studies performing serial ECG monitoring are warranted to enhance the understanding of dynamic QT interval changes in patients receiving QT-prolonging anti-TB agents.

Identifying patients with multidrug-resistant tuberculosis who may benefit from shorter durations of treatment

OBJECTIVE

Studying treatment duration for rifampicin-resistant and multidrug-resistant tuberculosis (MDR/RR-TB) using observational data is methodologically challenging. We aim to present a hypothesis generating approach to identify factors associated with shorter duration of treatment.

STUDY DESIGN AND SETTING

We conducted an individual patient data meta-analysis among MDR/RR-TB patients restricted to only those with successful treatment outcomes. Using multivariable linear regression, we estimated associations and their 95% confidence intervals (CI) between the outcome of individual deviation in treatment duration (in months) from the mean duration of their treatment site and patient characteristics, drug resistance, and treatments used.

RESULTS

Overall, 6702 patients with successful treatment outcomes from 84 treatment sites were included. We found that factors commonly associated with poor treatment outcomes were also associated with longer treatment durations, relative to the site mean duration. Use of bedaquiline was associated with a 0.51 (95% CI: 0.15, 0.87) month decrease in duration of treatment, which was consistent across subgroups, while MDR/RR-TB with fluoroquinolone resistance was associated with 0.78 (95% CI: 0.36, 1.21) months increase.

CONCLUSION

We describe a method to assess associations between clinical factors and treatment duration in observational studies of MDR/RR-TB patients, that may help identify patients who can benefit from shorter treatment.

Favourable outcomes in RR-TB patients using BPaL and other WHO-recommended second-line anti-TB drugs

SETTING: According to reports in South Africa, treatment failure rates for rifampicin-resistant TB (RR-TB) are significant and below the WHO target of ≥70%. HIV infection and the use of highly active antiretroviral therapy (HAART) influence how patients receiving anti-TB drugs respond to therapy. In the treatment of RR-TB, more recent medications, including bedaquiline, pretomanid and linezolid (BPaL), have shown promising results.OBJECTIVE: To assess treatment outcomes in RR-TB patients using BPaL and other second-line anti-TB drugs as recommended by the WHO in the South African population.DESIGN: The databases Medline, PubMed, Google Scholar and Embase were searched for studies between 2015 and 2022, which investigated BPaL outcomes in South Africa.RESULTS: Of the 27,259 participants, 21% were on bedaquiline, 1% were taking pretomanid and 9% were taking linezolid as part of their background regimen. About 68% of the patients were HIV-positive, with 59% of them taking HAART.CONCLUSION: Overall, 66% of patients taking BPaL drugs as part of their background regimen had favourable treatment outcomes. Additionally, patients with RR-TB who were HIV-positive and taking HAART while receiving BPaL drugs as part of a background regimen had improved treatment outcomes.

Pulmonary Tuberculosis in Children: A Forgotten Disease?

Even today, tuberculosis in childhood is a disease that is often undiagnosed and undertreated. In the absence of therapy with antituberculosis drugs, children in the first years of life have a high degree of severe forms and mortality. In these children, symptoms are often not very specific and can easily be confused with other diseases of bacterial, viral or fungal etiology, making diagnosis more difficult. Nevertheless, the introduction of new diagnostic techniques has allowed a more rapid identification of the infection. Indeed, Interferon gamma release assay (IGRA) is preferred to the Mantoux, albeit with obvious limitations in children aged <2 years. While the Xpert Mtb/RIF Ultra test is recommended as an initial diagnostic investigation of the gastric aspirate and/or stools in children with signs and symptoms of pulmonary tuberculosis. The drugs used in the treatment of susceptible and resistant TB are the same as those used in adults but doses and combinations are different in the pediatric age. In children, brief therapy is preferable in both the latent infection and the active disease, as a significant reduction in side effects is obtained.

Treatment Outcomes and Associated Factors among Tuberculosis Patients from Selected Rural Eastern Cape Hospitals: An Ambidirectional Study

An essential metric for determining the efficacy of tuberculosis (TB) control programs is the evaluation of TB treatment outcomes; this study was conducted to investigate treatment outcomes and associated factors among tuberculosis patients in rural areas of Eastern Cape, South Africa. Assessing treatment outcomes is fundamental to facilitating the End TB Strategy's set target. Clinic records from 457 patients with DR-TB were examined for data collection while 101 patients were followed up prospectively. Data were analyzed using Stata version 17.0. The odds ratio and 95% confidence interval were calculated to check the association between variables. p ≤ 0.05 was considered statistically significant. Of the 427 participants, 65.8% had successful treatment whilst 34.2% had unsuccessful TB treatment. A total of 61.2% and 39% of the HIV-positive and HIV-negative participants had a successful TB treatment whilst 66% and 34% of both HIV-negative and positive participants had unsuccessful TB treatment. From the 101 patients that were followed up, smokers took longer to have treatment outcomes compared to non-smokers. In the study with HIV/TB co-infection, men predominated. HIV and tuberculosis co-infection made therapy difficult with unfavorable effects on TB management. The treatment success rate (65.8%) was lower than the WHO threshold standard with a high proportion of patients being lost to the follow up. The co-infection of tuberculosis and HIV resulted in undesirable treatment outcomes. Strengthening TB surveillance and control is recommended.

Decentralized, Integrated Treatment of RR/MDR-TB and HIV Using a Bedaquiline-Based, Short-Course Regimen Is Effective and Associated With Improved HIV Disease Control

BACKGROUND

In decentralized sites, with fewer resources and a high prevalence of advanced HIV, the effectiveness of the new short-course, bedaquiline-based regimen for rifampicin-resistant and multidrug-resistant tuberculosis (RR/MDR-TB) is not well-described.

SETTING

Adults with pulmonary RR/MDR-TB initiating the short-course regimen in KwaZulu-Natal, South Africa were prospectively enrolled at a decentralized program that integrated person-centered TB care.

METHODS

In addition to standard of care monitoring, study visits occurred at enrollment and months 1, 2, 4, 6, and 9. Favorable RR/MDR-TB outcome was defined as cure or treatment completion without loss to follow-up, death, or failure by treatment. In patients with HIV, we assessed antiretroviral therapy (ART) uptake, virologic and immunologic outcomes.

RESULTS

Among 57 patients, HIV was present in 73.7% (95% CI: 60.3-84.5), with a median CD4 count of 170 cells/mm 3 (intraquartile range 49-314). A favorable RR/MDR-TB outcome was achieved in 78.9% (CI: 67.1-87.9). Three deaths occurred, all in the setting of baseline advanced HIV and elevated viral load. Overall, 21.1% (95% CI: 12.1-32.9) experienced a severe or life-threatening adverse event, the most common of which was anemia. Among patients with HIV, enrollment resulted in increased ART uptake by 24% (95% CI: 12.1%-39.4%), a significant improvement from baseline ( P = 0.004); virologic suppression during concomitant treatment was observed in 71.4% (n = 30, 95% CI: 55.4-84.3).

CONCLUSION

Decentralized, person-centered care for RR/MDR-TB in patients with HIV using the short-course, bedaquiline-based regimen is effective and safe. In patients with HIV, enrollment led to improved ART use and reassuring virologic outcomes.

Clinical implications of molecular drug resistance testing for Mycobacterium tuberculosis: a 2023 TBnet/RESIST-TB consensus statement

Drug-resistant tuberculosis is a substantial health-care concern worldwide. Despite culture-based methods being considered the gold standard for drug susceptibility testing, molecular methods provide rapid information about the Mycobacterium tuberculosis mutations associated with resistance to anti-tuberculosis drugs. This consensus document was developed on the basis of a comprehensive literature search, by the TBnet and RESIST-TB networks, about reporting standards for the clinical use of molecular drug susceptibility testing. Review and the search for evidence included hand-searching journals and searching electronic databases. The panel identified studies that linked mutations in genomic regions of M tuberculosis with treatment outcome data. Implementation of molecular testing for the prediction of drug resistance in M tuberculosis is key. Detection of mutations in clinical isolates has implications for the clinical management of patients with multidrug-resistant or rifampicin-resistant tuberculosis, especially in situations when phenotypic drug susceptibility testing is not available. A multidisciplinary team including clinicians, microbiologists, and laboratory scientists reached a consensus on key questions relevant to molecular prediction of drug susceptibility or resistance to M tuberculosis, and their implications for clinical practice. This consensus document should help clinicians in the management of patients with tuberculosis, providing guidance for the design of treatment regimens and optimising outcomes.

Update on drug treatments for multidrug resistant tuberculosis

PURPOSE OF THE REVIEW

To describe important recent developments in the treatment of multidrug resistant tuberculosis (MDR-TB).

RECENT FINDINGS

In the last decade, novel and repurposed antituberculosis drugs have transformed MDR-TB treatment with improved rates of treatment success, better tolerability and safety and reduced duration. As recently as 2016, standard care relied on up to seven drugs for 24 months with treatment success no better than 70%. Seven drug shorter so-called "Bangladesh" style regimens subsequently achieved similar or better results at a duration of 9-12 months but concerns about first-line resistance additional to rifampicin hampered global uptake. After conditional approval in 2012, the novel agent bedaquiline was demonstrated to improve outcomes and reduce mortality when used in longer and shorter regimens, resulting in the replacement of injectable agents. In the last 2 years, clinical trials of all-oral 6-month three or four drug regimens containing bedaquiline, pretomanid and linezolid have shown superior efficacy against both longer and shorter traditional regimens, resulting in major changes in WHO guidance.

SUMMARY

Although some concerns around safety and emergent bedaquiline resistance remain to be fully addressed, 6-month all oral regimens promise to transform the treatment of people with MDR-TB worldwide.

Impact of interventions for tuberculosis prevention and care in South Africa - a systematic review of mathematical modelling studies

BACKGROUND

Substantial additional efforts are needed to prevent, find and successfully treat tuberculosis (TB) in South Africa (SA). In thepast decade, an increasing body of mathematical modelling research has investigated the population-level impact of TB prevention and careinterventions. To date, this evidence has not been assessed in the SA context.

OBJECTIVE

To systematically review mathematical modelling studies that estimated the impact of interventions towards the World HealthOrganization's End TB Strategy targets for TB incidence, TB deaths and catastrophic costs due to TB in SA.

METHODS

We searched the PubMed, Web of Science and Scopus databases for studies that used transmission-dynamic models of TB in SAand reported on at least one of the End TB Strategy targets at population level. We described study populations, type of interventions andtheir target groups, and estimates of impact and other key findings. For studies of country-level interventions, we estimated average annualpercentage declines (AAPDs) in TB incidence and mortality attributable to the intervention.

RESULTS

We identified 29 studies that met our inclusion criteria, of which 7 modelled TB preventive interventions (vaccination,antiretroviral treatment (ART) for HIV, TB preventive treatment (TPT)), 12 considered interventions along the care cascade for TB(screening/case finding, reducing initial loss to follow-up, diagnostic and treatment interventions), and 10 modelled combinationsof preventive and care-cascade interventions. Only one study focused on reducing catastrophic costs due to TB. The highest impactof a single intervention was estimated in studies of TB vaccination, TPT among people living with HIV, and scale-up of ART. Forpreventive interventions, AAPDs for TB incidence varied between 0.06% and 7.07%, and for care-cascade interventions between 0.05%and 3.27%.

CONCLUSION

We describe a body of mathematical modelling research with a focus on TB prevention and care in SA. We found higherestimates of impact reported in studies of preventive interventions, highlighting the need to invest in TB prevention in SA. However, studyheterogeneity and inconsistent baseline scenarios limit the ability to compare impact estimates between studies. Combinations, rather thansingle interventions, are likely needed to reach the End TB Strategy targets in SA.

Nationwide Treatment Outcomes of Patients With Multidrug/Rifampin-Resistant Tuberculosis in Korea, 2011-2017: A Retrospective Cohort Study (Korean TB-POST)

BACKGROUND

The treatment outcomes of patients with multidrug/rifampin-resistant (MDR/RR) tuberculosis (TB) are important indicators that reflect the current status of TB management and identify the key challenges encountered by TB control programs in a country.

METHODS

We retrospectively evaluated the treatment outcomes as well as predictors of unfavorable outcomes in patients with MDR/RR-TB notified from 2011 to 2017, using an integrated TB database.

RESULTS

A total of 7,226 patients with MDR/RR-TB were included. The treatment success rate had significantly increased from 63.9% in 2011 to 75.1% in 2017 (P < 0.001). Among unfavorable outcomes, the proportion of patients who failed, were lost to follow up, and were not evaluated had gradually decreased (P < 0.001). In contrast, TB-related death rate was not significantly changed (P = 0.513), while the non-TB related death rate had increased from 3.2% in 2011 to 11.1% in 2017 (P < 0.001). Older age, male sex, immigrants, low household income, previous history of TB treatment, and comorbidities were independent predictors of unfavorable outcomes. Of the 5,308 patients who were successfully treated, recurrence occurred in 241 patients (4.5%) at a median 18.4 months (interquartile range, 9.2-32.4) after completion treatment.

CONCLUSION

The treatment outcomes of patients with MDR/RR-TB has gradually improved but increasing deaths during treatment is an emerging challenge for MDR-TB control in Korea. Targeted and comprehensive care is needed for vulnerable patients such as the elderly, patients with comorbidities, and those with low household incomes.

Social Determinants of Adherence to Treatment for Tuberculosis Infection and Disease Among Children, Adolescents, and Young Adults: A Narrative Review

Global efforts to eliminate tuberculosis (TB) must address the unique barriers that children (ages 0 through 9 years) and adolescents/young adults (AYA; ages 10 through 24 years) face in adhering to treatment for TB infection and disease. We conducted a narrative review to summarize current knowledge on the social determinants of treatment adherence among these age groups to guide efforts and policy to address their unique needs. Our findings revealed that research on TB treatment adherence among children and AYA is still in its nascent stage. The current literature revealed structural/community-, health system-, household-, and individual-level factors that influence treatment adherence and varied with developmental stage. There is a need to develop multilevel interventions to address the unique challenges that children and AYA face in adhering to TB treatment.

The Characteristics and Patterns of Drug-Resistant Pulmonary Tuberculosis in Eastern India

Background: Drug-resistant tuberculosis is a major public health problem throughout the world and accounts for substantial morbidity and mortality rates in India, too. Early diagnosis is the corner stone of tuberculosis treatment. State-level and cluster-wise variations in drug resistance is a possibility and should be regularly checked in from time to time. Materials and Methods: The present prospective cohort study (January 2019 to May 2022) was conducted in Darbhanga Medical College and Hospital on drug-resistant pulmonary tuberculosis patients. Sputum specimens were collected from designated centers. Rapid molecular drug-resistance testing (genotypic tests) and growth-based drug-susceptibility testing (DST) (phenotypic tests) were performed in the National Tuberculosis Elimination Program certified Laboratory. Results: A total of 268 patients with drug-resistant pulmonary tuberculosis were included in the study group. The treatment outcomes revealed as cured in 100 (37.31%); treatment completed in 43 (16.04%); died in 56 (20.89%); treatment failed in 22 (8.21%); loss of follow up in 34 (12.69%); and transferred out in 13 (4.85%) drug-resistant pulmonary tuberculosis patients. Adverse events were recorded in 199 (74.25%) of the drug-resistant pulmonary tuberculosis patients. Conclusions: Drug-resistant pulmonary tuberculosis patients are a matter of concern and need to be addressed.

Time to Culture Conversion of Bedaquiline and High-Dose Isoniazid for Drug-Resistant Tuberculosis

Patients with multidrug-resistant tuberculosis who received regimens containing high-dose isoniazid (INHHD) had similar time to culture conversion and treatment outcomes as patients who received regimens with bedaquiline. INHHD is an inexpensive and safe medication that may contribute additive efficacy in combination regimens.