The effect of directly observed therapy on the rates of drug resistance and relapse in tuberculosis

Major adverse cardiovascular events and hyperuricemia during tuberculosis treatment

BACKGROUND

Hyperuricemia is common during tuberculosis (TB) treatment, especially in association with pyrazinamide (PZA). This study investigated the relationship between major adverse cardiovascular events (MACEs) and hyperuricemia during TB treatment.

METHODS

We conducted a single-center retrospective cohort study. From January 2010 through June 2017, we assessed all consecutive TB patients at Chonnam National University Hospital in South Korea. Hyperuricemia was defined as serum uric acid levels exceeding 7.0 mg/dL (men) and 6.0 mg/dL (women).

RESULTS

Of the 1,143 patients included, PZA was administered to 1,081 (94.6%), and hyperuricemia was detected in 941 (82.3%). Eight patients experienced MACEs. Multivariate analysis using logistic regression indicated that prior ischemic heart disease was associated with MACE development (OR,14.087; 95% CI,3.304-60.061; P < 0.000), while hyperuricemia was not (OR, 1.505; 95% CI, 0.184-12.299; P = 0.703). For patients without drug-resistant TB, the absence of hyperuricemia was associated with higher mortality (OR, 2.609; 95% CI, 1.066-6.389; P = 0.036), whereas hyperuricemia was associated with less worse outcomes (OR,0.316; 95% CI,0.173-0.576; P < 0.000).

CONCLUSIONS

Although most patients treated with PZA developed hyperuricemia, it was not associated with MACE development. Hyperuricemia during TB treatment was associated with better outcomes, possibly due to consistent adherence to TB treatment.

The incidence of tuberculosis recurrence: Impacts of treatment duration of and adherence to standard anti-tuberculous therapy

BACKGROUND

We investigated the impacts of the standard treatment durations of and adherence to standard anti-tuberculous therapy (ATT) on recurrence after the successful completion of tuberculosis (TB) treatment.

METHODS

We recruited patients with TB who had received treatment for six or nine months from the 2008-2017 databases of the Taiwanese National Health Insurance Research Database. Treatment duration and adherence to standard ATT were analyzed for their impacts on recurrence within two years. Complete adherence to standard ATT was defined as daily use of ethambutol, isoniazid, pyrazinamide, and rifampin for the first two months, and daily use of isoniazid and rifampin for the first six months.

RESULTS

A total of 33,298 TB patients with new-onset TB were identified and classified into two groups by treatment duration: six months (n = 25,849, 77.63%) and nine months (n = 7449). Sex and age distributions varied between the groups. Treatment duration did not affect TB recurrence within two years (adjusted hazard ratio (AHR): 1.18, 95% confidence interval (C.I.) [0.96-1.44], p = 0.1156). Multivariable logistic regression showed that incomplete adherence to standard anti-tuberculous therapy (80-89% and 90-99% standard anti-TB therapy, AHR: 1.57, 95% C.I. [1.26-1.95], and 1.63, 95% C.I. [1.26-2.06], respectively, p < 0.0001) increased TB recurrence. In addition, male sex, older age, and comorbidity with diabetes mellitus or chronic obstructive pulmonary disease were independent risk factors for TB recurrence within two years.

CONCLUSIONS

TB recurrence was 1.54% within two years under a DOT era. TB treatment durations of six or nine months did not affect TB recurrence within two years after completion of TB treatment, but incomplete adherence to standard anti-tuberculous therapy might increase the TB recurrence rate.

Determinants of Unsuccessful TB Treatment Outcomes Among Patients on Directly Observed Treatment Short Course in Jimma Town Health Facilities, Southwest Ethiopia: A Case-Control Study

Background

Even though Ethiopia's Federal Ministry of Health has been implementing several programs aimed at reducing the burden of tuberculosis (TB), It does not demonstrate adequate progress. As a result, identifying the determinants of unsuccessful outcomes of directly observed treatment, short-course (DOTS) is critical.

Purpose

This study aimed to assess the determinants of unsuccessful TB treatment outcomes among patients with DOTS in Jimma town, southwest Ethiopia.

Patients and Methods

An unmatched case-control study using secondary data was conducted among 118 cases and 472 controls from April 1 to June 1, 2021. Cases were TB cases with unsuccessful treatment courses whereas controls were those of successful treatment. Data were collected using a standardized tool. Statistical analysis was done using SPSS version 23 software. A binary logistic regression model was used to identify the determinants.

Results

We found that the determinants including age > 35 years (AOR=1.9, 95% CI: 1.14-3.2), lack of contact person (AOR= 27, 95% CI: 15.8-46.3), being HIV positive (AOR=7.3, 95% CI: 3.7-14.2)), and being malnourished (AOR=4.5, 95% CI: 1.5-12.9) were significantly associated with unsuccessful tuberculosis treatment outcome.

Conclusion

In this study, advanced age, being HIV positive, lack of contact person, and being malnourished were determinant factors for unsuccessful TB treatment outcomes. Hence, careful monitoring, screening, and management of risk factors are recommended.

Effects of antibiotic interaction on antimicrobial resistance development in wastewater

While wastewater is understood to be a critically important reservoir of antimicrobial resistance due to the presence of multiple antibiotic residues from industrial and agricultural runoff, there is little known about the effects of antibiotic interactions in the wastewater on the development of resistance. We worked to fill this gap in quantitative understanding of antibiotic interaction in constant flow environments by experimentally monitoring E. coli populations under subinhibitory concentrations of combinations of antibiotics with synergistic, antagonistic, and additive interactions. We then used these results to expand our previously developed computational model to account for the effects of antibiotic interaction. We found that populations grown under synergistic and antagonistic antibiotic conditions exhibited significant differences from predicted behavior. E. coli populations grown with synergistically interacting antibiotics developed less resistance than predicted, indicating that synergistic antibiotics may have a suppressive effect on resistance development. Furthermore E. coli populations grown with antagonistically interacting antibiotics showed an antibiotic ratio-dependent development of resistance, suggesting that not only antibiotic interaction, but relative concentration is important in predicting resistance development. These results provide critical insight for quantitatively understanding the effects of antibiotic interactions in wastewater and provide a basis for future studies in modelling resistance in these environments.

Spatiotemporal perspectives on tuberculosis chemotherapy

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), accounts for over ten million infections and over 1.5 million deaths every year [1]. Upon infection, the seesaw between Mtb and our immune systems creates microenvironments that are compositionally distinctive and changing over time. While the field has begun to better understand the spatial complexity of TB disease, our understanding and experimental dissection of the temporal dynamics of TB and TB drug treatment is much more rudimentary. However, it is the combined spatiotemporal heterogeneity of TB disease that creates niches and time windows within which the pathogen can survive and thrive during treatment. Here, we review the emerging data on the interactions of spatial and temporal dynamics as they relate to TB disease and treatment. A better understanding of the interactions of Mtb, host, and antibiotics through space and time will elucidate treatment failure and potentially identify opportunities for new TB treatment regimens.

Disrupting the ArcA Regulatory Network Amplifies the Fitness Cost of Tetracycline Resistance in Escherichia coli

There is an urgent need for strategies to discover secondary drugs to prevent or disrupt antimicrobial resistance (AMR), which is causing >700,000 deaths annually. Here, we demonstrate that tetracycline-resistant (TetR) Escherichia coli undergoes global transcriptional and metabolic remodeling, including downregulation of tricarboxylic acid cycle and disruption of redox homeostasis, to support consumption of the proton motive force for tetracycline efflux. Using a pooled genome-wide library of single-gene deletion strains, at least 308 genes, including four transcriptional regulators identified by our network analysis, were confirmed as essential for restoring the fitness of TetR E. coli during treatment with tetracycline. Targeted knockout of ArcA, identified by network analysis as a master regulator of this new compensatory physiological state, significantly compromised fitness of TetR E. coli during tetracycline treatment. A drug, sertraline, which generated a similar metabolome profile as the arcA knockout strain, also resensitized TetR E. coli to tetracycline. We discovered that the potentiating effect of sertraline was eliminated upon knocking out arcA, demonstrating that the mechanism of potential synergy was through action of sertraline on the tetracycline-induced ArcA network in the TetR strain. Our findings demonstrate that therapies that target mechanistic drivers of compensatory physiological states could resensitize AMR pathogens to lost antibiotics. IMPORTANCE Antimicrobial resistance (AMR) is projected to be the cause of >10 million deaths annually by 2050. While efforts to find new potent antibiotics are effective, they are expensive and outpaced by the rate at which new resistant strains emerge. There is desperate need for a rational approach to accelerate the discovery of drugs and drug combinations that effectively clear AMR pathogens and even prevent the emergence of new resistant strains. Using tetracycline-resistant (TetR) Escherichia coli, we demonstrate that gaining resistance is accompanied by loss of fitness, which is restored by compensatory physiological changes. We demonstrate that transcriptional regulators of the compensatory physiologic state are promising drug targets because their disruption increases the susceptibility of TetR E. coli to tetracycline. Thus, we describe a generalizable systems biology approach to identify new vulnerabilities within AMR strains to rationally accelerate the discovery of therapeutics that extend the life span of existing antibiotics.

Effects of Antibiotic Interaction on Antimicrobial Resistance Development in Wastewater

While wastewater is understood to be a critically important reservoir of antimicrobial resistance due to the presence of multiple antibiotic residues from industrial and agricultural runoff, there is little known about the effects of antibiotic interactions in the wastewater on the development of resistance. We worked to fill this gap in quantitative understanding of antibiotic interaction in constant flow environments by experimentally monitoring E. coli populations under subinhibitory concentrations of combinations of antibiotics with synergistic, antagonistic, and additive interactions. We then used these results to expand our previously developed computational model to account for the complex effects of antibiotic interaction. We found that while E. coli populations grown in additively interacting antibiotic combinations grew predictably according to the previously developed model, those populations grown under synergistic and antagonistic antibiotic conditions exhibited significant differences from predicted behavior. E. coli populations grown in the condition with synergistically interacting antibiotics developed less resistance than predicted, indicating that synergistic antibiotics may have a suppressive effect on antimicrobial resistance development. Furthermore E. coli populations grown in the condition with antagonistically interacting antibiotics showed an antibiotic ratio-dependent development of resistance, suggesting that not only antibiotic interaction, but relative concentration is important in predicting resistance development. These results provide critical insight for quantitatively understanding the effects of antibiotic interactions in wastewater and provide a basis for future studies in modelling resistance in these environments.

Importance

Antimicrobial resistance (AMR) is a growing global threat to public health expected to impact 10 million people by 2050, driving mortality rates globally and with a disproportionate effect on low- and middle-income countries. Communities in proximity to wastewater settings and environmentally contaminated surroundings are at particular risk due to resistance stemming from antibiotic residues from industrial and agricultural runoff. Currently, there is a limited quantitative and mechanistic understanding of the evolution of AMR in response to multiple interacting antibiotic residues in constant flow environments. Using an integrated computational and experimental methods, we find that interactions between antibiotic residues significantly affect the development of resistant bacterial populations.

An efficient CRISPR interference-based prediction method for synergistic/additive effects of novel combinations of anti-tuberculosis drugs

Tuberculosis (TB) is treated by chemotherapy with multiple anti-TB drugs for a long period, spanning 6 months even in a standard course. In perspective, to prevent the emergence of antimicrobial resistance, novel drugs that act synergistically or additively in combination with major anti-TB drugs and, if possible, shorten the duration of TB therapy are needed. However, their combinatorial effect cannot be predicted until the lead identification phase of the drug development. Clustered regularly interspaced short palindromic repeats interference (CRISPRi) is a powerful genetic tool that enables high-throughput screening of novel drug targets. The development of anti-TB drugs promises to be accelerated by CRISPRi. This study determined whether CRISPRi could be applicable for predictive screening of the combinatorial effect between major anti-TB drugs and an inhibitor of a novel target. In the checkerboard assay, isoniazid killed Mycobacterium smegmatis synergistically or additively in combinations with rifampicin or ethambutol, respectively. The susceptibility to rifampicin and ethambutol was increased by knockdown of inhA, which encodes a target molecule of isoniazid. Additionally, knockdown of rpoB, which encodes a target molecule of rifampicin, increased the susceptibility to isoniazid and ethambutol, which act synergistically with rifampicin in the checkerboard assay. Moreover, CRISPRi could successfully predict the synergistic action of cyclomarin A, a novel TB drug candidate, with isoniazid or rifampicin. These results demonstrate that CRISPRi is a useful tool not only for drug target exploration but also for screening the combinatorial effects of novel combinations of anti-TB drugs. This study provides a rationale for anti-TB drug development using CRISPRi.

Potential to Use Fingerprints for Monitoring Therapeutic Levels of Isoniazid and Treatment Adherence

A fingerprint offers a convenient, noninvasive sampling matrix for monitoring therapeutic drug use. However, a barrier to widespread adoption of fingerprint sampling is the fact that the sample volume is uncontrolled. Fingerprint samples (n = 140) were collected from patients receiving the antibiotic isoniazid as part of their treatment, as well as from a drug-naive control group (n = 50). The fingerprint samples were analyzed for isoniazid (INH) and acetylisoniazid (AcINH), using liquid chromatography high-resolution mass spectrometry. The data set was analyzed retrospectively for metabolites known to be present in eccrine sweat. INH or AcINH was detected in 89% of the fingerprints collected from patients and in 0% of the fingerprints collected from the control group. Metabolites lysine, ornithine, pyroglutamic acid, and taurine were concurrently detected alongside INH/AcINH and were used to determine whether the fingerprint sample was sufficient for testing. Given a sufficient sample volume, the fingerprint test for INH use has sensitivity, specificity, and accuracy of 100%. Normalization to taurine was found to reduce intradonor variability. Fingerprints are a novel and noninvasive approach to monitor INH therapy. Metabolites can be used as internal markers to demonstrate a sufficient sample volume for testing and reduce intradonor variability.

Analysis of the Research Hotspot of Drug Treatment of Tuberculosis: A Bibliometric Based on the Top 50 Cited Literatures

Objective

The objective of the current study was to analyze the research hotspot of drug treatment for tuberculosis via top literatures.

Materials and Methods

A retrospective analysis was performed on June 7th, 2021. Literatures were searched on the Web of Science Core Collection to identify the top 50 cited literatures related to drug treatment of tuberculosis. The characteristics of the literatures were identified. The outcomes included authorship, journal, study type, year of publication, and institution. Cooccurrence network analysis and visualization were conducted using the VOS viewer (Version 1.6.16; Leiden University, Leiden, The Netherlands).

Results

The top 50 cited literatures were cited 308 to 2689 times and were published between 1982 and 2014. The most studied drugs were the first-line drugs such as isoniazid and rifampicin (n = 22), and drug-resistant tuberculosis was most frequently reported (n = 16). They were published in 18 journals, and the New England Journal of Medicine published the most literatures (n = 18), followed by the American Journal of Respiratory and Critical Care Medicine (n = 7), and the Lancet (n = 6). The authors were from 13 countries, and the authors from the USA published most of the literatures (n = 30), while authors from other countries published less than five literatures. The CDC in the USA (n = 4), the World Health Organization (WHO) (n = 3), and the American Philosophical Society (n = 3) were the leading institutions, and only two authors published at least two top-cited literatures as first authors.

Conclusions

This study provides insights into the development and most important literatures on drug therapy for tuberculosis and evidence for future research on tuberculosis treatment.

In-Person vs Electronic Directly Observed Therapy for Tuberculosis Treatment Adherence: A Randomized Noninferiority Trial

IMPORTANCE

Electronic directly observed therapy (DOT) is used increasingly as an alternative to in-person DOT for monitoring tuberculosis treatment. Evidence supporting its efficacy is limited.

OBJECTIVE

To determine whether electronic DOT can attain a level of treatment observation as favorable as in-person DOT.

DESIGN, SETTING, AND PARTICIPANTS

This was a 2-period crossover, noninferiority trial with initial randomization to electronic or in-person DOT at the time outpatient tuberculosis treatment began. The trial enrolled 216 participants with physician-suspected or bacteriologically confirmed tuberculosis from July 2017 to October 2019 in 4 clinics operated by the New York City Health Department. Data analysis was conducted between March 2020 and April 2021.

INTERVENTIONS

Participants were asked to complete 20 medication doses using 1 DOT method, then switched methods for another 20 doses. With in-person therapy, participants chose clinic or community-based DOT; with electronic DOT, participants chose live video-conferencing or recorded videos.

MAIN OUTCOMES AND MEASURES

Difference between the percentage of medication doses participants were observed to completely ingest with in-person DOT and with electronic DOT. Noninferiority was demonstrated if the upper 95% confidence limit of the difference was 10% or less. We estimated the percentage of completed doses using a logistic mixed effects model, run in 4 modes: modified intention-to-treat, per-protocol, per-protocol with 85% or more of doses conforming to the randomization assignment, and empirical. Confidence intervals were estimated by bootstrapping (with 1000 replicates).

RESULTS

There were 173 participants in each crossover period (median age, 40 years [range, 16-86 years]; 140 [66%] men; 80 [37%] Asian and Pacific Islander, 43 [20%] Black, and 71 [33%] Hispanic individuals) evaluated with the model in the modified intention-to-treat analytic mode. The percentage of completed doses with in-person DOT was 87.2% (95% CI, 84.6%-89.9%) vs 89.8% (95% CI, 87.5%-92.1%) with electronic DOT. The percentage difference was -2.6% (95% CI, -4.8% to -0.3%), consistent with a conclusion of noninferiority. The 3 other analytic modes yielded equivalent conclusions, with percentage differences ranging from -4.9% to -1.9%.

CONCLUSIONS AND RELEVANCE

In this trial, the percentage of completed doses under electronic DOT was noninferior to that under in-person DOT. This trial provides evidence supporting the efficacy of this digital adherence technology, and for the inclusion of electronic DOT in the standard of care.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03266003.

Cost-effectiveness of video-observed therapy for ambulatory management of active tuberculosis during the COVID-19 pandemic in a high-income country

OBJECTIVE

The coronavirus 2019 (COVID-19) pandemic caused suspension of directly observed therapy (DOT) for patients with active tuberculosis (TB). This study aimed to estimate the outcomes of pandemic-related DOT suspension and the cost-effectiveness of video-observed therapy (VOT) during the pandemic.

METHODS

A decision-analytic model was constructed to project outcomes of adult patients with active TB from the perspective of a US healthcare provider. Two model-based analyses were conducted: (1) before (with DOT) and during [with self-administered therapy (SAT)] the pandemic; and (2) VOT vs SAT during the pandemic. The primary outcome measures were direct medical costs and disability-adjusted life years (DALYs).

RESULTS

In the base-case analysis, care during the pandemic (with SAT) increased the cost (by US$285 per patient) and DALYs (by 0.2155 per patient) in comparison with DOT. Care with VOT reduced DALYs (by 0.4870) and costs (by US$1797) in comparison with SAT. On probabilistic sensitivity analysis, care during the pandemic (with SAT) increased DALYs in 100% of 10,000 simulations, and increased costs in 55.52% of instances. Care with VOT reduced DALYs and costs in 99.7% and 68.79% of instances, respectively. The probability of VOT being cost-effective was 99.4% at the willingness-to-pay threshold of 50,000 US$/DALY.

CONCLUSION

Suspension of DOT during the COVID-19 pandemic worsened treatment outcomes. VOT was found to be a cost-effective option for active TB care in an outpatient setting.

Tuberculosis treatment incompletion in patients with lung cancer: occurrence and predictors

BACKGROUND

Lung cancer patients are high-risk for active tuberculosis (TB); however, fragility and drug-drug interaction might lead to TB treatment interruption. TB treatment incompletion occurrence and predictors among lung cancer patients remain unclear.

METHODS

We recruited lung cancer patients with new-onset TB from Taiwan Cancer Registry and Taiwanese National Health Insurance 2007-2015 databases. TB treatment incompletion was the identified primary outcome, and associated risk factors were analyzed.

RESULTS

A total of 1155 lung cancer patients with new-onset TB were identified and classified as treatment incompletion (n=706, 61.13%) or completion (n=449). Gender and age distribution was similar in both groups. Under multivariable logistic regression, advanced cancer (stage III and IV) and no first-line TB drugs use were independent factors for treatment incompletion; but older age was not significant. For patients surviving >1 year since TB diagnosis, independent factors for treatment incompletion included no first-line TB drugs use (except pyrazinamide) and absence of hypertension. Cancer stage had borderline significance.

CONCLUSIONS

TB treatment incompletion occurred in 61.13% of lung cancer patients. Clinicians should carefully titrate anti-TB medications and monitor side effects in lung cancer patients, especially those with treatment incompletion risk factors, to avoid treatment interruption due to fragility and/or drug intolerance.

The impact of the COVID-19 epidemic on tuberculosis control in China

BACKGROUND

In response to the COVID-19 epidemic, China implemented a series of interventions that impacted tuberculosis (TB) control in the country.

METHODS

Based on routine surveillance data and questionnaires, the study analyzed TB notification, follow-up examinations, and treatment outcomes. The data were split into three phases in relation to outbreak, lockdown and reopen when the nationwide COVID-19 response started in 2020: control (11 weeks prior), intensive (11 weeks during and immediately after), and regular (4 additional weeks). Data from 2017-2019 were used as baseline.

FINDINGS

The notified number of TB patients decreased sharply in the 1st week of the intensive period but took significantly longer to rebound in 2020 compared with baseline. The percentages of TB patients undergoing sputum examination within one week after 2 months treatment and full treatment course in the intensive period were most affected and decreased by 8% in comparison with control period. 75•2% (221/294) of counties reallocated CDC and primary health care workers to fight the COVID-19 epidemic, 26•9% (725/2694) of TB patients had postponed or missed their follow-up examinations due to travel restrictions and fear of contracting COVID-19.

INTERPRETATION

In the short term, the COVID-19 epidemic mostly affected TB notification and follow-up examinations in China, which may lead to a surge of demand for TB services in the near future. To cope with this future challenge, an emergency response mechanism for TB should be established.

FUNDING

National Health Commission of China-Bill & Melinda Gates Foundation TB Collaboration project (OPP1137180).

Effect of a Daily Text Messaging and Directly Supervised Therapy Intervention on Oral Mercaptopurine Adherence in Children With Acute Lymphoblastic Leukemia: A Randomized Clinical Trial

Importance

Suboptimal adherence to oral mercaptopurine treatment in children with acute lymphoblastic leukemia (ALL) increases the risk of relapse. A frequently expressed barrier to adherence is forgetfulness, which is often overcome by parental vigilance.

Objective

To determine whether a multicomponent intervention, compared with education alone, will result in a higher proportion of patients with ALL who have mercaptopurine adherence rates 95% or higher, for all study participants and among patients younger than 12 years and vs those aged 12 years and older.

Design, Setting, and Participants

The adherence intervention trial was an investigator-initiated, multi-institutional, parallel-group, unblinded, randomized clinical trial conducted between July 16, 2012, and August 8, 2018, at 59 Children's Oncology Group institutions in the US, enrolling patients with ALL diagnosed through age 21 years and receiving mercaptopurine for maintenance. The date of final follow-up was January 2, 2019. Data analysis was performed from February to October 2019.

Interventions

Patients were randomized 1:1 to education alone or the intervention package, which consisted of education and personalized text message reminders daily to prompt directly supervised therapy. Four weeks of baseline adherence monitoring were followed with a 16-week intervention.

Main Outcomes and Measures

The primary end point was the proportion of patients with adherence rates 95% or higher over the duration of the intervention for all study participants, and for those younger than 12 years vs those aged 12 years and older.

Results

There were 444 evaluable patients (median age, 8.1 years; interquartile range, 5.3-14.3 years), including 230 in the intervention group and 214 in the education group. Three hundred two patients (68.0%) were boys, 180 (40.5%) were non-Hispanic White, 170 (38.3%) were Hispanic, 43 (9.7%) were African American, and 51 (11.5%) were Asian or of mixed race/ethnicity. The proportion of patients with adherence rates 95% or higher did not differ between the intervention vs education groups (65% vs 59%; odds ratio, 1.33; 95% CI, 1.0-2.0; P = .08). Exploratory analyses showed that among patients aged 12 years and older, those in the intervention group had higher mean (SE) adherence rates than those in the education group (93.1% [1.1%] vs 90.0% [1.3%]; difference, 3.1%; 95% CI, 0.1%-6.0%; P = .04). In particular, among patients aged 12 years and older with baseline adherence less than 90%, those in the intervention group had higher mean (SE) adherence rates than those in the education group (83.4% [2.5%] vs 74.6% [3.4%]; difference, 8.8%; 95% CI, 2.2%-15.4%; P = .008). No safety concerns were identified.

Conclusions and Relevance

Although this multicomponent intervention did not result in an increase in the proportion of patients with ALL who had mercaptopurine adherence rates 95% or higher, it did identify a high-risk subpopulation to target for future adherence intervention strategies: adolescents with low baseline adherence.

Trial Registration

ClinicalTrials.gov Identifier: NCT01503632.

A Comprehensive App That Improves Tuberculosis Treatment Management Through Video-Observed Therapy: Usability Study

BACKGROUND

Treatment of pulmonary tuberculosis (TB) requires at least six months and is compromised by poor adherence. In the directly observed therapy (DOT) scheme recommended by the World Health Organization, the patient is directly observed taking their medications at a health post. An alternative to DOT is video-observed therapy (VOT), in which the patients take videos of themselves taking the medication and the video is uploaded into the app and reviewed by a health care worker. We developed a comprehensive TB management system by using VOT that is installed as an app on the smartphones of both patients and health care workers. It was implemented into the routine TB control program of the Nanshan District of Shenzhen, China.

OBJECTIVE

The aim of this study was to compare the effectiveness of VOT with that of DOT in managing the treatment of patients with pulmonary TB and to evaluate the acceptance of VOT for TB management by patients and health care workers.

METHODS

Patients beginning treatment between September 2017 and August 2018 were enrolled into the VOT group and their data were compared with the retrospective data of patients who began TB treatment and were managed with routine DOT between January 2016 and August 2017. Sociodemographic characteristics, clinical features, treatment adherence, positive findings of sputum smears, reporting of side effects, time and costs of transportation, and satisfaction were compared between the 2 treatment groups. The attitudes of the health care workers toward the VOT-based system were also analyzed.

RESULTS

This study included 158 patients in the retrospective DOT group and 235 patients in the VOT group. The VOT group showed a significantly higher fraction of doses observed (P<.001), less missed observed doses (P<.001), and fewer treatment discontinuations (P<.05) than the DOT group. Over 79.1% (186/235) of the VOT patients had >85% of their doses observed, while only 16.4% (26/158) of the DOT patients had >85% of their doses observed. All patients were cured without recurrences. The VOT management required significantly (P<.001) less median patient time (300 minutes vs 1240 minutes, respectively) and transportation costs (¥53 [US $7.57] vs ¥276 [US $39.43], respectively; P<.001) than DOT. Significantly more patients (191/235, 81.3%) in the VOT group preferred their treatment method compared to those on DOT (37/131, 28.2%) (P<.001), and 92% (61/66) of the health care workers thought that the VOT method was more convenient than DOT for managing patients with TB.

CONCLUSIONS

Implementation of the VOT-based system into the routine program of TB management was simple and it significantly increased patient adherence to their drug regimens. Our study shows that a comprehensive VOT-based TB management represents a viable and improved evolution of DOT.

A Framework for Network-Based Epidemiological Modeling of Tuberculosis Dynamics Using Synthetic Datasets

We present a framework for discrete network-based modeling of TB epidemiology in US counties using publicly available synthetic datasets. We explore the dynamics of this modeling framework by simulating the hypothetical spread of disease over 2 years resulting from a single active infection in Washtenaw County, MI. We find that for sufficiently large transmission rates that active transmission outweighs reactivation, disease prevalence is sensitive to the contact weight assigned to transmissions between casual contacts (that is, contacts that do not share a household, workplace, school, or group quarter). Workplace and casual contacts contribute most to active disease transmission, while household, school, and group quarter contacts contribute relatively little. Stochastic features of the model result in significant uncertainty in the predicted number of infections over time, leading to challenges in model calibration and interpretation of model-based predictions. Finally, predicted infections were more localized by household location than would be expected if they were randomly distributed. This modeling framework can be refined in later work to study specific county and multi-county TB epidemics in the USA.

Challenges and controversies in the treatment of spinal tuberculosis

Current guidelines regarding management of spinal TB are mostly extrapolated from trials on pulmonary disease. Since the British Medical Research Council (BMRC) trials in the 1970s, there are not many good quality studies that substantiate best practice guidelines for the management of this entity. Tuberculous infection of the spine behaves much differently from bacterial osteomyelitis and limited data leads to ambiguity in many cases. Although a few studies have been conducted in patients with spinal TB, most were in the era preceding short course chemotherapy and prior to current radiological and surgical advances. While spinal TB is primarily managed medically, surgical intervention may be needed in certain cases. We discuss areas of uncertainty and challenges that exist with regards to medical treatment, diagnosis, therapeutic endpoints, and a few surgical considerations. Substantial delay in diagnosis continues to be common with this disease even in the developed nations, leading to substantial morbidity. In light of limited evidence, there is an emerging recognition of the need to individualize various aspects of its treatment such as duration, frequency and acknowledging the limitations of various diagnostic and radiological modalities. We aim to consolidate potential areas of research in the diagnosis and management of spinal TB and to revisit the latest published evidence on its redressal.

The Dual-Targeting Activity of the Metabolite Substrate of Para-amino Salicyclic Acid in the Mycobacterial Folate Pathway: Atomistic and Structural Perspectives

Therapeutic targeting of folate biosynthetic pathway has recently been explored as a viable strategy in the treatment of tuberculosis. The bioactive metabolite substrate of Para-amino salicyclic acid (PAS-M) reportedly dual-targets dihydrofolate reductase (DHFR) and flavin-dependent thymidylate synthase (FDTS), two essential enzymes in folate biosynthetic pathway. However, the molecular mechanisms and structural dynamics of this dual inhibitory activity of the PAS-M remain elusive. Molecular dynamics simulations revealed that binding of PAS-M towards DHFR is characterized by a recurrence of strong conventional hydrogen bond interactions between a peculiar DHFR binding site residue (Asp27) and the 2-amino-decahydropteridin-4-ol group of PAS-M. Similarly, the binding of PAS-M towards FDTS also involved consistent strong conventional hydrogen bond interactions between some specific residues (Tyr101, Arg172, Thr4, Gln103, Arg87 and Gln106) and, the 2-amino-decahydropteridin-4-ol group, thus establishing the cruciality of the group. Structural dynamics of the bound complexes of both enzymes revealed that, upon binding, PAS-M is anchored at the entrance of hydrophobic pockets by strong hydrogen bond interactions while the rest of the structure gains access to deeper hydrophobic residues to engage in favorable interactions. Further analysis of atomistic changes of both enzymes showed increased C-α atom deviations as well as an increase C-α atoms radius of gyration consistent with structural disorientations. These conformational changes possibly interfered with the biological functions of the enzymes and hence their inhibition as experimentally reported. Structural Insights provided could open up a novel paradigm of structure-based design of multi-targeting inhibitors of biological targets in the folate biosynthetic pathway toward tuberculosis therapy.

The importance of adherence in tuberculosis treatment clinical trials and its relevance in explanatory and pragmatic trials

Andrew Vernon and co-authors discuss adherence to therapy and its measurement in tuberculosis treatment trials.

Transmissibility and potential for disease progression of drug resistant Mycobacterium tuberculosis: prospective cohort study

OBJECTIVE

To measure the association between phenotypic drug resistance and the risk of tuberculosis infection and disease among household contacts of patients with pulmonary tuberculosis.

SETTING

106 district health centers in Lima, Peru between September 2009 and September 2012.

DESIGN

Prospective cohort study.

PARTICIPANTS

10 160 household contacts of 3339 index patients with tuberculosis were classified on the basis of the drug resistance profile of the patient: 6189 were exposed to drug susceptible strains of Mycobacterium tuberculosis, 1659 to strains resistant to isoniazid or rifampicin, and 1541 to strains that were multidrug resistant (resistant to isoniazid and rifampicin).

MAIN OUTCOME MEASURES

Tuberculosis infection (positive tuberculin skin test) and the incidence of active disease (diagnosed by positive sputum smear or chest radiograph) after 12 months of follow-up.

RESULTS

Household contacts exposed to patients with multidrug resistant tuberculosis had an 8% (95% confidence interval 4% to 13%) higher risk of infection by the end of follow-up compared with household contacts of patients with drug sensitive tuberculosis. The relative hazard of incident tuberculosis disease did not differ among household contacts exposed to multidrug resistant tuberculosis and those exposed to drug sensitive tuberculosis (adjusted hazard ratio 1.28, 95% confidence interval 0.9 to 1.83).

CONCLUSION

Household contacts of patients with multidrug resistant tuberculosis were at higher risk of tuberculosis infection than contacts exposed to drug sensitive tuberculosis. The risk of developing tuberculosis disease did not differ among contacts in both groups. The evidence invites guideline producers to take action by targeting drug resistant and drug sensitive tuberculosis, such as early detection and effective treatment of infection and disease.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00676754.

Improvement in Tuberculosis Outcomes With a Combined Medical and Social Approach

Setting: Studies performed locally in Switzerland in the late eighties reported unsatisfactory treatment outcomes. Better outcomes were observed since the introduction of directly observed therapy (DOT) in the late nineties and improvement in social support in recent years. Design: retrospective study of treatment outcomes for all tuberculosis (TB) patients notified in Vaud County (VD), Switzerland, between, 1st of January 2010 and 31st of December of 2014. Results: 375 patients were notified in VD during the study period. The global outcome was successful in 90.1% of patients (338/375). In 183 culture and PCR positive pulmonary TB, the documented cure rate was 57.9% (106/183), and the treatment completion was 59/183 (32.2%), i.e., a treatment success of 90.2%. DOT was applied globally in 234/375 (62.4%) and in 64/67 of the asylum seekers (AS) (95.5%) followed at the dispensary. Treatment outcomes were successful in 60/67 (89.6%) AS. Discussion: Improvements in tuberculosis outcomes resulted not only from the introduction of DOT in VD in the nineties but also from a change in the management, with increased attention to the social problems faced by the migrants. Conclusion: A combined medical and social approach of TB care in VD improved treatment outcomes.

Predictors of recurrent TB in sputum smear and culture positive adults: a prospective cohort study

Objective

To explore simple inexpensive non-culture based predictors of recurrent pulmonary tuberculosis (PTB).

Setting and study population

HIV-infected and uninfected adults with the first episode of smear positive, culture-confirmed pulmonary tuberculosis in a high tuberculosis burden country.

Design

A nested prospective cohort study of participants with pulmonary tuberculosis (PTB) presenting to a hospital out-patient clinic.

Results

A total of 630 TB culture confirmed participants were followed up for eighteen months of which 57 (9%) developed recurrent recurrent TB. On univariate analysis,4.7% low grade(1+) pre-treatment sputum smear participants developed recurrent tuberculosis Vs 8.8% with high grade(3+) smears (OR=0.31,95%CI: 0.10–0.93, p=0.037).On multivariate analysis: participants with extensive fibro-cavitation had a high risk of recurrent TB Vs minimal end of treatment fibro-cavitation (18%Vs12%, OR=2.3,95%CI:1.09–4.68, p=0.03). Weight gain with HIV infection was assosciated with a high risk of recurrent TB Vs weight gain with no HIV infection(18%Vs 6%, OR=6.8,95%CI:165–27.83, p=0.008) where as weight gain with a low pre-treatment high bacillary burden was assosciated with a low risk of recurrent TB Vs weight gain with a high pre-treatmentbacillary burden(6.5%Vs7.9%, OR=0.2,95%CI:0.05–0.79, p=0.02).

Conclusion

Extensive end of treatment pulmonary fibro-cavitation, high pre-treatment bacillary burden with no weight gain and HIV infection could be reliable predictors of recurrent tuberculosis.

Successful Fixation of a Tuberculous Nonunion of the Humeral Shaft: A Case Report

CASE

A 48-year-old man from North Africa with a history of infection after fixation of a humeral fracture presented 8 years later with an infected nonunion. After operative debridement, Mycobacterium tuberculosis grew on culture. Following a 2-stage surgical procedure and medical management of the tuberculosis (TB), successful union had been achieved at the 1-year follow-up.

CONCLUSION

Nonunion of the humerus caused by TB is a rare entity, but careful attention to patient demographics can forewarn the care provider. Irrigation and debridement with the Masquelet technique followed by compression plating and an iliac crest autograft can provide positive results.

Assessment and Treatment of Nonadherence in Transplant Recipients

Stable intake of an immunosuppressant medication regimen is essential for posttransplant survival in the vast majority of cases. And yet, many patients are nonadherent (do not take their medications as prescribed), and suffer consequences ranging from rejection to morbidity and mortality. We review the evidence related to monitoring of adherence to medications, and intervention strategies. Our aim is to provide a baseline from which readers may approach behavioral aspects of posttransplant care. This review may also help readers in designing clinical programs for routine monitoring of adherence, and inform the choice of intervention when adherence falls below a certain threshold.

Treatment of drug-susceptible tuberculosis among people living with human immunodeficiency virus infection: an update

PURPOSE OF REVIEW

The present review describes recent advances in the treatment of drug-susceptible tuberculosis (DS-TB) among people living with human immunodeficiency virus (PLWH).

RECENT FINDINGS

Higher than standard rifampicin doses (>10 mg/kg/day) are well tolerated and have improved sterilizing activity. Standard pyrazinamide doses may result in low drug exposures; modeling reveals that higher doses (>25 mg/kg/day) may be required to reach target levels, although safety is unknown. Four-month fluoroquinolone-containing regimens are not recommended in the 2017 World Health Organization DS-TB treatment guidelines. These guidelines also recommend fixed-dose combination (FDC) therapy over single drug formulations based on patient preference, though FDC is not associated with improved outcomes. Treatment for 6 months is recommended, with an emphasis on expanded antiretroviral therapy (ART) coverage and monitoring for relapse among those not started on ART within 8 weeks of tuberculosis treatment. Directly observed therapy (DOT) is recommended over self-administered therapy, as is daily therapy over intermittent therapy - both are associated with better tuberculosis outcomes.

SUMMARY

Current WHO tuberculosis treatment guidelines recommend 6 months of daily tuberculosis treatment for PLWH who have DS-TB, and timely ART initiation. Higher rifampin and pyrazinamide doses may enhance treatment effectiveness, but safety data are needed. DOT and FDC therapy are recommended.

Clinically prevalent mutations in Mycobacterium tuberculosis alter propionate metabolism and mediate multidrug tolerance

The global epidemic of drug-resistant tuberculosis is a catastrophic example of how antimicrobial resistance is undermining the public health gains made possible by combination drug therapy. Recent evidence points to unappreciated bacterial factors that accelerate the emergence of drug resistance. In a genome-wide association study of Mycobacterium tuberculosis isolates from China, we find mutations in the gene encoding the transcription factor prpR enriched in drug-resistant strains. prpR mutations confer conditional drug tolerance to three of the most effective classes of antibiotics by altering propionyl-CoA metabolism. prpR-mediated drug tolerance is carbon-source dependent, and while readily detectable during infection of human macrophages, is not captured by standard susceptibility testing. These data define a previously unrecognized and clinically prevalent class of M. tuberculosis variants that undermine antibiotic efficacy and drive drug resistance.

Alcohol enhances type 1 interferon-α production and mortality in young mice infected with Mycobacterium tuberculosis

In the current study, we used a mouse model and human blood samples to determine the effects of chronic alcohol consumption on immune responses during Mycobacterium tuberculosis (Mtb) infection. Alcohol increased the mortality of young mice but not old mice with Mtb infection. CD11b+Ly6G+ cells are the major source of IFN-α in the lungs of Mtb-infected alcohol-fed young mice, and IFN-α enhances macrophage necroptosis in the lungs. Treatment with an anti-IFNAR-1 antibody enhanced the survival of Mtb-infected alcohol-fed young mice. In response to Mtb, peripheral blood mononuclear cells (PBMCs) from alcoholic young healthy individuals with latent tuberculosis infection (LTBI) produced significantly higher amounts of IFN-α than those from non-alcoholic young healthy LTBI+ individuals and alcoholic and non-alcoholic old healthy LTBI+ individuals. Our study demonstrates that alcohol enhances IFN-α production by CD11b+Ly6G+ cells in the lungs of young Mtb-infected mice, which leads to macrophage necroptosis and increased mortality. Our findings also suggest that young alcoholic LTBI+ individuals have a higher risk of developing active TB infection.

Chronic alcohol consumption modulates the host immune defense mechanism(s) and makes the host susceptible to various fungal, viral and bacterial infections, including Mycobacterium tuberculosis (Mtb). However, limited information is available about the mechanisms involved in alcohol-mediated host susceptibility to Mtb and other intracellular bacterial infections. In the current study, we fed control and alcohol diets to young and old mice and determined the mortality rates and the immune mechanisms involved in host susceptibility to Mtb infection. We found that alcohol increases the mortality of young mice but not old mice infected with Mtb. The increased mortality in alcohol-fed Mtb-infected young mice was due to IFN-α production by CD11b+Ly6G+ cells. We also found that PBMCs from young alcoholic individuals with latent tuberculosis infection (LTBI) produced significantly higher amounts of IFN-α than those from young non-alcoholic, old alcoholic and old non-alcoholic LTBI+ individuals. Our findings suggest that young alcoholic LTBI+ individuals have a higher risk of developing active TB infection. Our studies provide the first evidence that chronic alcohol consumption induces IFN-α production in young Mtb-infected mice and increases their mortality rates. Further characterization of CD11b+Ly6G+ cells and delineation of the mechanisms through which alcohol enhances IFN-α production in Ly6G+ cells during Mtb infection will facilitate the development of therapies for alcoholic individuals with latent and active Mtb.

Adherence interventions and outcomes of tuberculosis treatment: A systematic review and meta-analysis of trials and observational studies

BACKGROUND

Incomplete adherence to tuberculosis (TB) treatment increases the risk of delayed culture conversion with continued transmission in the community, as well as treatment failure, relapse, and development or amplification of drug resistance. We conducted a systematic review and meta-analysis of adherence interventions, including directly observed therapy (DOT), to determine which approaches lead to improved TB treatment outcomes.

METHODS AND FINDINGS

We systematically reviewed Medline as well as the references of published review articles for relevant studies of adherence to multidrug treatment of both drug-susceptible and drug-resistant TB through February 3, 2018. We included randomized controlled trials (RCTs) as well as prospective and retrospective cohort studies (CSs) with an internal or external control group that evaluated any adherence intervention and conducted a meta-analysis of their impact on TB treatment outcomes. Our search identified 7,729 articles, of which 129 met the inclusion criteria for quantitative analysis. Seven adherence categories were identified, including DOT offered by different providers and at various locations, reminders and tracers, incentives and enablers, patient education, digital technologies (short message services [SMSs] via mobile phones and video-observed therapy [VOT]), staff education, and combinations of these interventions. When compared with DOT alone, self-administered therapy (SAT) was associated with lower rates of treatment success (CS: risk ratio [RR] 0.81, 95% CI 0.73-0.89; RCT: RR 0.94, 95% CI 0.89-0.98), adherence (CS: RR 0.83, 95% CI 0.75-0.93), and sputum smear conversion (RCT: RR 0.92, 95% CI 0.87-0.98) as well as higher rates of development of drug resistance (CS: RR 4.19, 95% CI 2.34-7.49). When compared to DOT provided by healthcare providers, DOT provided by family members was associated with a lower rate of adherence (CS: RR 0.86, 95% CI 0.79-0.94). DOT delivery in the community versus at the clinic was associated with a higher rate of treatment success (CS: RR 1.08, 95% CI 1.01-1.15) and sputum conversion at the end of two months (CS: RR 1.05, 95% CI 1.02-1.08) as well as lower rates of treatment failure (CS: RR 0.56, 95% CI 0.33-0.95) and loss to follow-up (CS: RR 0.63, 95% CI 0.40-0.98). Medication monitors improved adherence and treatment success and VOT was comparable with DOT. SMS reminders led to a higher treatment completion rate in one RCT and were associated with higher rates of cure and sputum conversion when used in combination with medication monitors. TB treatment outcomes improved when patient education, healthcare provider education, incentives and enablers, psychological interventions, reminders and tracers, or mobile digital technologies were employed. Our findings are limited by the heterogeneity of the included studies and lack of standardized research methodology on adherence interventions.

CONCLUSION

TB treatment outcomes are improved with the use of adherence interventions, such as patient education and counseling, incentives and enablers, psychological interventions, reminders and tracers, and digital health technologies. Trained healthcare providers as well as community delivery provides patient-centered DOT options that both enhance adherence and improve treatment outcomes as compared to unsupervised, SAT alone.

Recurrence of tuberculosis in a low-incidence setting: a retrospective cross-sectional study augmented by whole genome sequencing

Background

The recurrence of tuberculosis (TB) disease in treated patients can serve as a marker of the efficacy of TB control programs. Recurrent disease represents either endogenous reactivation with the same strain of Mycobacterium tuberculosis due to non-compliance or inadequate therapy or exogenous reinfection with a new strain. Genotyping or whole genome sequencing (WGS) of M. tuberculosis isolates from initial and recurrent cases can differentiate between reinfection and reactivation. This study examined cases of recurrent TB in New South Wales, Australia, using genotyping and WGS.

Methods

Culture-confirmed TB cases diagnosed at least 12 months apart between January 2011 and December 2016 were included. Isolates of M. tuberculosis from patients were compared using 24-locus Mycobacterial Interspersed Repetitive Unit Variable Number Tandem Repeat (MIRU-24) typing and WGS.

Results

Eighteen cases of recurrent disease were identified but isolates from only 15 (83%) were available for study. MIRU-24 findings classified 13 (13/15; 87%) as reactivation and two (13%), as reinfection. Sequencing 13 cultivable paired isolates demonstrated 11 reactivations and two reinfections. There was genomic similarity in 10 out of 13 pairs while one case (1/13; 8%) had 12 SNPS differences. Two other cases (2/13;15%) had > 200 SNPs differences and were classified as reinfection. No phenotypic or genomic evidence of drug resistance was observed.

Conclusion

TB control programs can achieve consistently low rates of recurrent disease in low incidence settings. WGS of implicated isolates augments the differentiation between reactivation and reinfection and indicates that the majority of recurrences are due to reactivation rather than reinfection. Predominance of reactivation over reinfection indicates high-quality public health practices and a low risk of local transmission.

Trial registration

This study was approved by the Western Sydney Local Health District (WSLHD) Human Research Ethics Committee (HREC Ref: AU RED LNR/17/WMEAD/190; SSA Ref: LNR SSA/17/WMEAD/191).

The use of illustrated medication diaries to improve outcomes for children initiated on highly active antiretroviral therapy

Background: Human immunodeficiency virus (HIV) represents a huge burden of disease in South Africa. Highly active antiretroviral therapy (HAART) is effective in reducing HIV-related morbidity and mortality. Simple, inexpensive methods like adherence diaries to optimise effects of HAART would be useful.Methods: This quasi-experimental study was performed at a paediatric antiretroviral clinic in KwaZulu-Natal, South Africa. Children, from birth to 15 years, initiated on HAART from 01 August 2015 to 31 July 2016 were given illustrated medication diaries to be completed by caregivers. Viral load suppression and improvement in growth parameters and CD4+ percentage were determined at six months and one year. These outcomes were compared to those of a group of children who had been initiated on HAART from 01 August 2014 to 31 July 2015 and who had not received diaries.Results: Ninety-nine children were included in the historical control group and 35 children in the intervention group. Viral load suppression (HIV-1 RNA of < 400 copies/mL) was 72% in the control group and 71% in the diary group at 6 months (p = 0.6). At 12 months, 73% of children in the control group and 57% of the diary group had suppressed viral loads (p = 0.18). At 6 months, 63% of children in the control group and 57% of the diary group had improved weight for height z-scores (p = 0.09). At 12 months, when compared with baseline weight for height z-scores, there was improvement in 34% and 41% of the control and diary groups, respectively (p = 0.6). CD4+ percentages improved in 51% of the control group and 50% of the diary group at 6 months (p = 0.70); improvement was noted in 44% and 49%, respectively, at 12 months (p = 0.33).Conclusion: The addition of an illustrated medication diary to routine adherence counselling did not improve outcomes for children initiated on HAART.

SMS reminders to improve adherence and cure of tuberculosis patients in Cameroon (TB-SMS Cameroon): a randomised controlled trial

BACKGROUND

In Cameroon, the National Tuberculosis Control Program that applies selective directly observed treatments faces difficulties in its implementation for a lack of resources, leading to only 65% of patients with sputum smear-positive pulmonary tuberculosis being cured after 6 months of treatment. This study aimed to evaluate the effectiveness of daily Short Message Service reminders to increase adherence and the proportion of adult tuberculosis patients cured after 6 months of treatment.

METHODS

A simple blinded, randomised controlled, multicentre study carried out in 12 Treatment and Diagnostic Centres of Yaoundé. The patients included were randomly assigned to two groups: patients in the intervention group received daily SMS reminders in addition to the usual treatment; those in the control group received the usual treatment only. The primary outcomes were the number and proportion of treatment success at 5 months, and the number and proportion of patients cured at 6 months. Data analysis was by intention to treat.

RESULTS

Two hundred and seventy-nine participants were randomized into intervention group (n = 137) and control group (n = 142). At five months, there were 111 treatment success (81%) in the intervention group and 106 (74.6%) in the control group (OR = 1.45 [0.81, 2.56]; p = 0.203). At 6 months, there were 87 patients cured (63.5%) in the intervention group and 88 (62%) in the control group (OR = 1.06 [0.65, 1.73]; p = 0.791). The number of drop-outs at 6 months was 47 (34.3%) in intervention group, and 46 (32.4%) in the control group. 48.9% (23/47) and 39.1% (18/46) of these drop-outs were sputum-negative at 5 months. At three different appointments, there were no significant differences between the two groups in any secondary outcomes. Very high and similar satisfaction was found for general management of patients in both groups: 99.5 and 99.2% (p = 0.41).

CONCLUSIONS

Our study suggests that SMS reminders do not increase treatment success and cure proportions. However, the low proportion of patients cured at 6 month may be an underestimation due to a high dropout rate between the fifth and the sixth months of treatment. Future trials should focus on reducing the dropout rate.

TRIAL REGISTRATION

The trial was registered on the Pan-African Clinical Trials Registry ( PACTR201307000583416 of 22 July 2013) and the protocol was published.

Directly observed therapy of sofosbuvir/ribavirin +/- peginterferon with minimal monitoring for the treatment of chronic hepatitis C in people with a history of drug use in Chennai, India (C-DOT)

We assessed the feasibility of field-based directly observed therapy (DOT) with minimal monitoring to deliver HCV treatment to people with a history of drug use in Chennai, India. Fifty participants were randomized 1:1 to sofosbuvir+peginterferon alfa 2a+ribavirin (SOF+PR) for 12 weeks (Arm 1) vs sofosbuvir+ribavirin (SOF+R) for 24 weeks (Arm 2). SOF+R was delivered daily at participant chosen venues and weekly peginterferon injections at the study clinic. HCV RNA testing was performed to confirm active HCV infection and sustained virologic response 12 weeks after treatment completion (SVR12). No baseline genotyping or on-treatment viral loads were performed. Median age was 46 years. All were male and 20% had significant fibrosis/cirrhosis. All self-reported history of injection drug use, 18% recent noninjection drug use and 38% alcohol dependence. Six discontinued treatment (88% completed treatment in each arm). Of 22 who completed SOF+PR, all achieved SVR12 (22/25=88%); 15 of 22 who completed SOF+R achieved SVR12 (15/25=60%; P=.05). Among those completing SOF+R, SVR12 was significantly less common in participants reporting ongoing substance use (36% vs 100%) and missed doses. Active substance use and missed doses did not impact SVR with SOF+PR. Field-based DOT of HCV therapy without real-time HCV RNA monitoring was feasible; however, achieving 100% adherence was challenging. SOF+PR appeared superior to SOF+R in achieving SVR12, even when doses were missed with no discontinuations due to side effects. Further exploration of short duration treatment with peginterferon plus direct-acting antivirals is warranted.

Impact of mobile teams on tuberculosis treatment outcomes, Riyadh Region, Kingdom of Saudi Arabia, 2013-2015

The objective of this study was to evaluate the impact of the tuberculosis (TB) mobile teams on treatment outcomes in Riyadh Region by comparing patients who received treatment under mobile teams and those who did not, from 2013 to 2015. This was a retrospective descriptive study using National TB Control and Prevention Program data from 2013 to 2015 from Riyadh, Kingdom of Saudi Arabia. Descriptive analyses were used to summarize characteristics of TB case-patients served by mobile teams and those who were not served. The χ² test measured the significant differences between mobile-served and non-mobile-served case-patients. Exposure was whether or not the TB case-patient was under the care of the mobile team; the outcome of interest was whether or not treatment was successful, defined as treatment completed and cured. We found that the ratio of treatment success among mobile team case-patients was 1.28 greater than among those not served by mobile teams. The χ² test showed a statistically significant finding (probability ratio=1.28; 95% confidence interval=1.21-1.35, p<0.01). Mobile teams increased the treatment success rate to 92%, compared to 71.77% among those not served by mobile teams. This study shows that community mobilization of mobile teams is an effective strategy to enhance TB treatment, reduced mortality and loss to follow-up and improve TB treatment outcomes.

Usability of a Medication Event Reminder Monitor System (MERM) by Providers and Patients to Improve Adherence in the Management of Tuberculosis

Poor initiation and implementation and premature discontinuation of anti-tuberculous therapy, all forms of nonadherence, are major reasons for treatment failure, the development of drug-resistant tuberculosis, and transmission to other non-infected individuals. Directly Observed Therapy (DOT) has been the worldwide standard, but implementation of DOT is burdensome for providers and patients, especially in resource-limited settings, where most of the burden of active TB is located. Among the alternatives to DOT is electronic monitoring (EM) of drug dosing histories. Here we report a usability study of a newly-designed, modular electronic monitor product, called the MERM (Medication Event and Reminder Monitor), that is compatible with TB medication formats and supply chains in resource-limited settings. This study, done in a rural setting in China, showed that the use of the MERM for EM of TB medications was associated with a high degree of user performance, acceptability, and satisfaction among both TB patients and medical staff. Based on these data, EM is becoming the standard of care for drug-susceptible TB patients in China and scaled implementations in several other countries with high TB burden have begun. In addition, the MERM is being used in MDR-TB patients and in clinical trials involving patients with TB/HIV and latent TB.

Mycobacterium tuberculosis PhoY Proteins Promote Persister Formation by Mediating Pst/SenX3-RegX3 Phosphate Sensing

The Mycobacterium tuberculosis phosphate-specific transport (Pst) system controls gene expression in response to phosphate availability by inhibiting the activation of the SenX3-RegX3 two-component system under phosphate-rich conditions, but the mechanism of communication between these systems is unknown. In Escherichia coli, inhibition of the two-component system PhoR-PhoB under phosphate-rich conditions requires both the Pst system and PhoU, a putative adaptor protein. E. coli PhoU is also involved in the formation of persisters, a subpopulation of phenotypically antibiotic-tolerant bacteria. M. tuberculosis encodes two PhoU orthologs, PhoY1 and PhoY2. We generated phoY single- and double-deletion mutants and examined the expression of RegX3-regulated genes by quantitative reverse transcription-PCR (qRT-PCR). Gene expression was increased only in the ΔphoY1 ΔphoY2 double mutant and could be restored to the wild-type level by complementation with either phoY1 or phoY2 or by deletion of regX3 These data suggest that the PhoY proteins function redundantly to inhibit SenX3-RegX3 activation. We analyzed the frequencies of antibiotic-tolerant persister variants in the phoY mutants using several antibiotic combinations. Persister frequency was decreased at least 40-fold in the ΔphoY1 ΔphoY2 mutant compared to the frequency in the wild type, and this phenotype was RegX3 dependent. A ΔpstA1 mutant lacking a Pst system transmembrane component exhibited a similar RegX3-dependent decrease in persister frequency. In aerosol-infected mice, the ΔphoY1 ΔphoY2 and ΔpstA1 mutants were more susceptible to treatment with rifampin but not isoniazid. Our data demonstrate that disrupting phosphate sensing mediated by the PhoY proteins and the Pst system enhances the susceptibility of M. tuberculosis to antibiotics both in vitro and during infection.IMPORTANCE Persister variants, subpopulations of bacteria that are phenotypically antibiotic tolerant, contribute to the lengthy treatment times required to cure Mycobacterium tuberculosis infection, but the molecular mechanisms governing their formation and maintenance are poorly characterized. Here, we demonstrate that a phosphate-sensing signal transduction system, comprising the Pst phosphate transporter, the two-component system SenX3-RegX3, and functionally redundant PhoY proteins that mediate signaling between Pst and SenX3-RegX3, influences persister formation. Activation of RegX3 by deletion of the phoY genes or a Pst system component resulted in decreased persister formation in vitro Activated RegX3 also limited persister formation during growth under phosphate-limiting conditions. Importantly, increased susceptibility to the front-line drug rifampin was also observed in a mouse infection model. Thus, the M. tuberculosis phosphate-sensing signal transduction system contributes to antibiotic tolerance and is a potential target for the development of novel therapeutics that may shorten the duration of tuberculosis treatment.

Chemotherapy of Tuberculosis

The management of tuberculosis (TB) can be a challenging process that has implications both for the affected patient and public health. Effective anti-TB chemotherapy both cures and renders the patient noncontagious. Biological factors specific to M. tuberculosis necessitate the use of multiple drugs for prolonged durations to adequately eradicate infection. Recommended regimens address the complexities of eliminating organisms from diverse reservoirs while preventing the emergence of drug resistance. First-line anti-TB therapy for drug susceptible disease effectively cures almost all patients within 6-9 months. The loss of first-line agents, due to resistance or intolerance, necessitates lengthy treatment courses, frequently 12-18 months or longer. Due to the long treatment times and the implications of missed doses, directly-observed therapy (DOT) is considered the standard of care. Drugs used for the treatment of TB have serious potential toxicities that require close monitoring and prompt response. A strong public health infrastructure and robust social supports are important elements to assure successful treatment. These numerous factors compel public health entities to take a lead role in the management of TB, either through the direct management of TB treatment or by assuring the activities of partner organizations.

Treatment delay and fatal outcomes of pulmonary tuberculosis in advanced age: a retrospective nationwide cohort study

BACKGROUND AND OBJECTIVE

Studies focusing on pulmonary tuberculosis in advanced age (≥80 years) are lacking. This study aimed to explore treatment delay, outcomes and their predictors in this group.

METHODS

Adult (≥20 years) patients with pulmonary tuberculosis were identified from the National Health Insurance Research Database of Taiwan from 2004 to 2009. Treatment completion and mortality rates were noted at one year after treatment.

RESULTS

Among the 81,081 patients with pulmonary tuberculosis identified, 13,923 (17.2%) were aged ≥80 years, and 26,897 (33.2%) were aged 65-79 years. The treatment completion, mortality rates and treatment delay were 54.8%, 34.7% and 61 (12-128) [median, (1st-3rd quartiles)] days in patients aged ≥80 years, 68.3%, 18.5% and 53 (8-122) days in patients aged 65-79 years, and 78.9%, 6.5% and 21 (1-84) days in patients aged <65 years, respectively. The elder patients were more likely to receive second-line anti-tuberculosis agents. The treatment completion rate decreased with older age, female sex, comorbidities, low income, requiring second-line anti-tuberculosis agents, severity of pulmonary tuberculosis and longer treatment delay. Older age, female sex, comorbidities, low income, and not undergoing rapid molecular diagnostic tests were independently associated with longer treatment delays.

CONCLUSIONS

Pulmonary tuberculosis in advanced age has a longer treatment delay and a higher mortality rate. Applying rapid molecular diagnostic tools may reduce treatment delay and should be integrated into the diagnostic algorithm for pulmonary tuberculosis, particularly in elderly patients.

Rifampin Stability and Solution Concentration Enhancement Through Amorphous Solid Dispersion in Cellulose ω-Carboxyalkanoate Matrices

Tuberculosis (TB) is a deadly infectious disease; approximately 2 billion people are currently latently infected with the causative agent Mycobacterium tuberculosis. Approximately 8 million new active cases and 2 million deaths due to TB are recorded annually.¹ Rifampin (Rif) is a vital first-line TB treatment drug. Its effectiveness is hampered by the high dose required (600 mg 1×/day) and by its moderate, variable bioavailability. These issues can be explained by Rif instability at gastric pH, limited solubility at neutral pH, polymorphism, and stimulation of its own metabolism. To overcome these obstacles, we developed new cellulose-based oral drug delivery systems aiming to increase and make more consistent Rif solubility and bioavailability. Amorphous solid dispersions (ASDs) of Rif with cellulose ω-carboxyalkanoates (cellulose acetate suberate, cellulose acetate propionate adipate, and cellulose acetate butyrate sebacate) were prepared and compared with crystalline Rif (negative) and carboxymethyl cellulose acetate butyrate ASD (positive) controls. Cellulose ω-carboxyalkanoate ASDs prevented acid-catalyzed degradation in conditions mimicking the acidic stomach and provided complete release of intact Rif at intestinal pH. Rif incorporation into ASD in these novel cellulose derivative matrices creates the potential for convenient, robust, consistent, and high Rif oral bioavailability for treatment of TB.

Estimating the future burden of multidrug-resistant and extensively drug-resistant tuberculosis in India, the Philippines, Russia, and South Africa: a mathematical modelling study

BACKGROUND

Multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis are emerging worldwide. The Green Light Committee initiative supported programmatic management of drug-resistant tuberculosis in 90 countries. We used estimates from the Preserving Effective TB Treatment Study to predict MDR and XDR tuberculosis trends in four countries with a high burden of MDR tuberculosis: India, the Philippines, Russia, and South Africa.

METHODS

We calibrated a compartmental model to data from drug resistance surveys and WHO tuberculosis reports to forecast estimates of incident MDR and XDR tuberculosis and the percentage of incident MDR and XDR tuberculosis caused by acquired drug resistance, assuming no fitness cost of resistance from 2000 to 2040 in India, the Philippines, Russia, and South Africa.

FINDINGS

The model forecasted the percentage of MDR tuberculosis among incident cases of tuberculosis to increase, reaching 12·4% (95% prediction interval 9·4-16·2) in India, 8·9% (4·5-11·7) in the Philippines, 32·5% (27·0-35·8) in Russia, and 5·7% (3·0-7·6) in South Africa in 2040. It also predicted the percentage of XDR tuberculosis among incident MDR tuberculosis to increase, reaching 8·9% (95% prediction interval 5·1-12·9) in India, 9·0% (4·0-14·7) in the Philippines, 9·0% (4·8-14·2) in Russia, and 8·5% (2·5-14·7) in South Africa in 2040. Acquired drug resistance would cause less than 30% of incident MDR tuberculosis during 2000-40. Acquired drug resistance caused 80% of incident XDR tuberculosis in 2000, but this estimate would decrease to less than 50% by 2040.

INTERPRETATION

MDR and XDR tuberculosis were forecast to increase in all four countries despite improvements in acquired drug resistance shown by the Green Light Committee-supported programmatic management of drug-resistant tuberculosis. Additional control efforts beyond improving acquired drug resistance rates are needed to stop the spread of MDR and XDR tuberculosis in countries with a high burden of MDR tuberculosis.

FUNDING

US Agency for International Development and US Centers for Disease Control and Prevention, Division of Tuberculosis Elimination.

The within-host population dynamics of Mycobacterium tuberculosis vary with treatment efficacy

Background

Combination therapy is one of the most effective tools for limiting the emergence of drug resistance in pathogens. Despite the widespread adoption of combination therapy across diseases, drug resistance rates continue to rise, leading to failing treatment regimens. The mechanisms underlying treatment failure are well studied, but the processes governing successful combination therapy are poorly understood. We address this question by studying the population dynamics of Mycobacterium tuberculosis within tuberculosis patients undergoing treatment with different combinations of antibiotics.

Results

By combining very deep whole genome sequencing (~1000-fold genome-wide coverage) with sequential sputum sampling, we were able to detect transient genetic diversity driven by the apparently continuous turnover of minor alleles, which could serve as the source of drug-resistant bacteria. However, we report that treatment efficacy has a clear impact on the population dynamics: sufficient drug pressure bears a clear signature of purifying selection leading to apparent genetic stability. In contrast, M. tuberculosis populations subject to less drug pressure show markedly different dynamics, including cases of acquisition of additional drug resistance.

Conclusions

Our findings show that for a pathogen like M. tuberculosis, which is well adapted to the human host, purifying selection constrains the evolutionary trajectory to resistance in effectively treated individuals. Nonetheless, we also report a continuous turnover of minor variants, which could give rise to the emergence of drug resistance in cases of drug pressure weakening. Monitoring bacterial population dynamics could therefore provide an informative metric for assessing the efficacy of novel drug combinations.

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-017-1196-0) contains supplementary material, which is available to authorized users.

The epidemiology, pathogenesis, transmission, diagnosis, and management of multidrug-resistant, extensively drug-resistant, and incurable tuberculosis

Global tuberculosis incidence has declined marginally over the past decade, and tuberculosis remains out of control in several parts of the world including Africa and Asia. Although tuberculosis control has been effective in some regions of the world, these gains are threatened by the increasing burden of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis. XDR tuberculosis has evolved in several tuberculosis-endemic countries to drug-incurable or programmatically incurable tuberculosis (totally drug-resistant tuberculosis). This poses several challenges similar to those encountered in the pre-chemotherapy era, including the inability to cure tuberculosis, high mortality, and the need for alternative methods to prevent disease transmission. This phenomenon mirrors the worldwide increase in antimicrobial resistance and the emergence of other MDR pathogens, such as malaria, HIV, and Gram-negative bacteria. MDR and XDR tuberculosis are associated with high morbidity and substantial mortality, are a threat to health-care workers, prohibitively expensive to treat, and are therefore a serious public health problem. In this Commission, we examine several aspects of drug-resistant tuberculosis. The traditional view that acquired resistance to antituberculous drugs is driven by poor compliance and programmatic failure is now being questioned, and several lines of evidence suggest that alternative mechanisms-including pharmacokinetic variability, induction of efflux pumps that transport the drug out of cells, and suboptimal drug penetration into tuberculosis lesions-are likely crucial to the pathogenesis of drug-resistant tuberculosis. These factors have implications for the design of new interventions, drug delivery and dosing mechanisms, and public health policy. We discuss epidemiology and transmission dynamics, including new insights into the fundamental biology of transmission, and we review the utility of newer diagnostic tools, including molecular tests and next-generation whole-genome sequencing, and their potential for clinical effectiveness. Relevant research priorities are highlighted, including optimal medical and surgical management, the role of newer and repurposed drugs (including bedaquiline, delamanid, and linezolid), pharmacokinetic and pharmacodynamic considerations, preventive strategies (such as prophylaxis in MDR and XDR contacts), palliative and patient-orientated care aspects, and medicolegal and ethical issues.

The cursed duet today: Tuberculosis and HIV-coinfection

The tuberculosis (TB) and HIV syndemic continues to rage and are a major public health concern worldwide. This deadly association raises complexity and represent a significant barrier towards TB elimination. TB continues to be the leading cause of death amongst HIV-infected people. This paper reports the challenges that lay ahead and outlines some of the current and future strategies that may be able to address this co-epidemic efficiently. Improved diagnostics, cheaper and more effective drugs, shorter treatment regimens for both drug-sensitive and drug-resistant TB are discussed. Also, special topics on drug interactions, TB-IRIS and TB relapse are also described. Notwithstanding the defeats and meagre investments, diagnosis and management of the two diseases have seen significant and unexpected improvements of late. On the HIV side, expansion of ART coverage, development of new updated guidelines aimed at the universal treatment of those infected, and the increasing availability of newer, more efficacious and less toxic drugs are an essential element to controlling the two epidemics. On the TB side, diagnosis of MDR-TB is becoming easier and faster thanks to the new PCR-based technologies, new anti-TB drugs active against both sensitive and resistant strains (i.e. bedaquiline and delamanid) have been developed and a few more are in the pipeline, new regimens (cheaper, shorter and/or more effective) have been introduced (such as the "Bangladesh regimen") or are being tested for MDR-TB and drug-sensitive-TB. However, still more resources will be required to implement an integrated approach, install new diagnostic tests, and develop simpler and shorter treatment regimens.

Text messaging to decrease tuberculosis treatment attrition in TB-HIV coinfection in Uganda

BACKGROUND

Low tuberculosis (TB) treatment completion rates in sub-Saharan Africa are an important driver of multidrug resistance. Mobile technology-based interventions have been shown to improve adherence to antiretroviral therapy in sub-Saharan Africa. We aimed to test the effect of a short-message service (SMS) intervention on loss to follow-up (LFU).

MATERIALS AND METHODS

In this quasi-experimental study, all adult, literate, HIV-infected patients with mobile phone access diagnosed with TB between November 2010 and October 2011 in an urban clinic in Uganda were eligible to receive adherence and appointment reminders and educational quizzes during the first 8 weeks of TB treatment. Their risk of LFU in the first 8 weeks of treatment was compared with that of patients starting treatment between March 2009 and August 2010 using logistic regression.

RESULTS

One of 183 (0.5%) enrolled patients was lost to FU during the intervention compared to six of 302 (2.0%) in the preintervention control group (RR 0.27, 95% CI 0.03-2.07; P=0.22). The SMS intervention was rated as very helpful by 96%. Barriers identified included interrupted phone access (26%, median 14 days) and difficulties responding by SMS. The response rate to educational quizzes was below 10%. There were no unintentional disclosures of TB or HIV status due to the intervention.

CONCLUSION

An SMS reminder service did not show a clear effect on short-term risk of LFU in this study, which was underpowered due to a lower baseline risk in the control group than expected. The SMS-reminder service was rated highly, and there were no breaches of confidentiality. Important technological barriers have implications for larger-scale implementation, not only for TB but also other disease modalities.

Predictors and short-term outcomes of recurrent pulmonary tuberculosis, Uganda: a cohort study

INTRODUCTION

Recurrent tuberculosis (TB) occurring >2 years after completing treatment for a prior TB episode is most often due to reinfection with a new strain of M. tuberculosis.

OBJECTIVES

We determined the prevalence and outcome of late recurrent TB among hospitalized patients in Kampala, Uganda.

METHODS

We conducted a retrospective analysis of patients admitted to Mulago Hospital who had cough of >2 weeks' duration and completed TB treatment >2 years prior to admission. All patients had mycobacterial culture performed on two sputum specimens and vital status ascertained 2-months post-enrollment. We performed modeling to identify predictors of recurrent TB and of survival.

RESULTS

Among 234 patients, 84 (36%) had recurrent TB. Independent predictors included younger age (aOR=0.64, 95% CI=0.42-0.97, p=0.04), chest pain >2 weeks (aOR=3.32, 95% CI=1.38-8.02, p=0.007), severe weight loss ≥5 kilograms (aOR=4.88, 95% CI=1.66-14.29, p=0.004) and presence of ≥1 WHO danger sign of severe illness (aOR=3.55, 95% CI=1.36-9.29, p=0.01). Two-month mortality was 17.8% (95% CI=10.5-29.2%), and was higher among patients not initiated on TB treatment (aHR=16.67, 95% CI=1.18-200, p=0.04), not on ART if HIV-positive (aHR=16.99, 95% CI=1.17-246.47, p=0.04) and with a history of smoking (aHR=1.20, 95% CI=1.03-1.40, p=0.02).

CONCLUSION

The high prevalence of late recurrent TB likely reflects high levels of TB transmission in Kampala. Increased use of empiric TB treatment and early ART treatment initiation if HIV-positive should be considered in patients with a prior history of TB, particularly if young, with weight loss ≥5kgs, chest pain >2 weeks or ≥1 WHO danger sign of severe illness.

Official American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America Clinical Practice Guidelines: Treatment of Drug-Susceptible Tuberculosis

The American Thoracic Society, Centers for Disease Control and Prevention, and Infectious Diseases Society of America jointly sponsored the development of this guideline for the treatment of drug-susceptible tuberculosis, which is also endorsed by the European Respiratory Society and the US National Tuberculosis Controllers Association. Representatives from the American Academy of Pediatrics, the Canadian Thoracic Society, the International Union Against Tuberculosis and Lung Disease, and the World Health Organization also participated in the development of the guideline. This guideline provides recommendations on the clinical and public health management of tuberculosis in children and adults in settings in which mycobacterial cultures, molecular and phenotypic drug susceptibility tests, and radiographic studies, among other diagnostic tools, are available on a routine basis. For all recommendations, literature reviews were performed, followed by discussion by an expert committee according to the Grading of Recommendations, Assessment, Development and Evaluation methodology. Given the public health implications of prompt diagnosis and effective management of tuberculosis, empiric multidrug treatment is initiated in almost all situations in which active tuberculosis is suspected. Additional characteristics such as presence of comorbidities, severity of disease, and response to treatment influence management decisions. Specific recommendations on the use of case management strategies (including directly observed therapy), regimen and dosing selection in adults and children (daily vs intermittent), treatment of tuberculosis in the presence of HIV infection (duration of tuberculosis treatment and timing of initiation of antiretroviral therapy), as well as treatment of extrapulmonary disease (central nervous system, pericardial among other sites) are provided. The development of more potent and better-tolerated drug regimens, optimization of drug exposure for the component drugs, optimal management of tuberculosis in special populations, identification of accurate biomarkers of treatment effect, and the assessment of new strategies for implementing regimens in the field remain key priority areas for research. See the full-text online version of the document for detailed discussion of the management of tuberculosis and recommendations for practice.