Sustainability and impact of an intervention to improve initiation of tuberculosis preventive treatment: results from a follow-up study of the ACT4 randomized trial.

Background: In a cluster randomized trial (clinicaltrials.gov: NCT02810678) a flexible but comprehensive health system intervention significantly increased the number of household contacts (HHC) identified and started on tuberculosis preventive treatment (TPT). A follow-up study was conducted one year later to test the hypotheses that these effects were sustained, and were reproducible with a simplified intervention. Methods: We conducted a follow-up study from May 1, 2018 until April 30, 2019, as part of a multinational cluster randomized trial. Eight sites in 4 countries that had received the intervention in the original trial received no further intervention; eight other sites in the same countries that had not received the intervention (control sites in the original trial) now received a simplified version of the intervention. This consisted of repeated local evaluation of the Cascade of care for TB infection, and stakeholder decision making. The number of HHC identified and starting TPT were repeatedly measured at all 16 sites and expressed as rates per 100 newly diagnosed index TB patients. The sustained effect of the original intervention was estimated by comparing these rates after the intervention in the original trial with the last 6 months of the follow-up study. The reproducibility was estimated by comparing the pre-post intervention changes in rates at sites receiving the original intervention with the pre-post changes in rates at sites receiving the later, simplified intervention. Findings: With regard to the sustained impact of the original intervention, compared to the original post-intervention period, the number of HHC identified and treated per 100 newly diagnosed TB patients was 10 more (95% confidence interval: 84 fewer to 105 more), and 1 fewer (95% CI: 22 fewer to 20 more) respectively up to 14 months after the end of the original intervention. With regard to the reproducibility of the simplified intervention, at sites that had initially served as control sites, the number of HHC identified and treated per 100 TB patients increased by 33 (95% CI: -32, 97), and 16 (-69, 100) from 3 months before, to up to 6 months after receiving a streamlined intervention, although differences were larger, and significant if the post-intervention results were compared to all pre-intervention periods. Interpretation: Up to one year after it ended, a health system intervention resulted in sustained increases in the number of HHC identified and starting TPT. A simplified version of the intervention was associated with non-significant increases in the identification and treatment of HHC. Inferences are limited by potential bias due to other temporal effects, and the small number of study sites. Funding: Funded by the Canadian Institutes of Health Research (Grant number 143350).

High-dose, short-duration versus standard rifampicin for tuberculosis preventive treatment: a partially blinded, three-arm, non-inferiority, randomised, controlled trial.

BACKGROUND: Tuberculosis preventive treatment (TPT) is a key component of tuberculosis elimination. To improve completion and reduce the burden for people and health systems, short, safe, and effective TPT regimens are needed. We aimed to compare safety and treatment completion of various doses and durations of rifampicin in people who were recommended to receive TPT. METHODS: This partially blinded, parallel-arm, non-inferiority, randomised, controlled, phase 2b trial was done at seven university-affiliated clinics in Canada, Indonesia, and Viet Nam. Participants aged 10 years or older were included if they had an indication for TPT according to WHO guidelines for Indonesia and Viet Nam, or Canadian guidelines for Canadian sites, and a positive tuberculin skin test or interferon-γ release assay. Participants were randomly assigned (1:1:1) to receive oral rifampicin at 10 mg/kg once daily for 4 months (standard-dose group), 20 mg/kg daily for 2 months (20 mg/kg group), or 30 mg/kg daily for 2 months (30 mg/kg group). The randomisation sequence was computer generated with blocks of variable size (three, six, and nine) and stratified by country for Indonesia and Viet Nam, and by city within Canada. Participants and investigators were masked to dose in high-dose groups, but unmasked to duration in all groups. The two co-primary outcomes were safety (in the safety population, in which participants received at least one dose of the study drug) and treatment completion (in the modified intention-to-treat [mITT] population, excluding those ineligible after randomisation). Protocol-defined adverse events were defined as grade 3 or worse, or rash or allergy of any grade, judged by an independent and masked panel as possibly or probably related to the study. A margin of 4% was used to assess non-inferiority. This study is registered with ClinicalTrials.gov, NCT03988933 (active). FINDINGS: Between Sept 1, 2019, and Sept 30, 2022, 1692 people were assessed for eligibility, 1376 were randomly assigned, and eight were excluded after randomisation. 1368 participants were included in the mITT population (454 in the standard group, 461 in the 20 mg/kg group, and 453 in the 30 mg/kg group). 589 (43%) participants were male and 779 (57%) were female. 372 (82%) in the standard-dose group, 329 (71%) in the 20 mg/kg group, and 293 (65%) in the 30 mg/kg group completed treatment. No participants in the standard-dose group, one (<1%) of 441 participants in the 20 mg/kg group, and four (1%) of 423 in the 30 mg/kg group developed grade 3 hepatotoxicity. Risk of protocol-defined adverse events was higher in the 30 mg/kg group than in the standard-dose group (adjusted risk difference 4·6% [95% CI 1·8 to 7·4]) or the 20 mg/kg group (5·1% [2·3 to 7·8]). There was no difference in the risk of adverse events between the 20 mg/kg and standard-dose groups (-0·5% [95% CI -2·4 to 1·5]; non-inferiority met). Completion was lower in the 20 mg/kg group (-7·8% [95% CI -13·6 to -2·0]) and the 30 mg/kg group (-15·4% [-21·4 to -9·4]) than in the standard-dose group. INTERPRETATION: In this trial, 2 months of 30 mg/kg daily rifampicin had significantly worse safety and completion than 4 months of 10 mg/kg daily and 2 months of 20 mg/kg daily (the latter, a fully blinded comparison); we do not consider 30 mg/kg to be a good option for TPT. Rifampicin at 20 mg/kg daily for 2 months was as safe as standard treatment, but with lower completion. This difference remains unexplained. FUNDING: Canadian Institutes of Health Research.

High dose rifampin for 2 months vs standard dose rifampin for 4 months, to treat TB infection: Protocol of a 3-arm randomized trial (2R2).

INTRODUCTION: Tuberculosis preventive treatment (TPT) is an essential component for TB elimination. In order to be successfully implemented on a large scale, TPT needs to be safe, affordable and widely available in all settings. Short TPT regimens, that are less burdensome than longer regimens, to patients and health systems, are needed. Doses of rifampin higher than the standard 10mg/kg/day were tolerated in studies to reduce duration of treatment for tuberculosis disease (TBD). The objective of this trial is to test the safety of high dose rifampin monotherapy to shorten the duration of the currently recommended TPT of 4 months rifampin. METHODS AND ANALYSIS: This is a phase 2b, randomised, controlled, parallel group, superiority, partially-blind trial. Primary outcomes are completion of treatment (as a proxy measure of tolerability) and safety. The two experimental arms comprise 60 days of (i) 20mg/kg/day or (ii) 30mg/kg/day rifampin; the control arm comprises 120 days of 10mg/kg/day rifampin as TPT. Participants are adults and children 10 years or older, eligible for TPT. Completion is the primary outcome, measured by pill count and is defined as taking minimum of 80% of treatment in 120% of allowed time; it will be tested for superiority by logistic regression. Safety outcome comprises proportion of grade 3-5 adverse events and grade 1-2 rash, adjudicated related to study drug, and resulting in permanent drug discontinuation; compared for non-inferiority between each of the two high dose arms and the standard arm, using Poisson regression. A sample size of 1,359 participants will give 80% power to detect a 10% difference in completion rates and a 1% difference in the safety outcome. The study is conducted in Canada, Indonesia and Vietnam. Enrolment is ongoing at all sites. ETHICS AND DISSEMINATION: Approvals from a local research ethics board (REB) have been obtained at all participating sites and by the trial coordinating centre. Approval has been given by drug regulatory agencies in Canada and Indonesia and by Ministry of Health in Vietnam; participants give written informed consent before participation. All data collected are non-nominal. Primary results will be submitted for publication in a peer-reviewed journal when all participants have completed treatment; results of secondary outcomes will be submitted for publication at the end of study; all sites will receive the final data of participants from their sites. TRIAL REGISTRATION: Trial registered in ClinicalTrials.gov (Identifier: NCT03988933). Coordinating center is the study team working at McGill University Health Center-Research Institute (MUHC-RI); sponsor is the MUHC-RI; funding has been granted by Canadian Institute of Health Research (FDN-143350).

The respiratory microbiome and nontuberculous mycobacteria: an emerging concern in human health.

Nontuberculous mycobacteria (NTM) are diverse microbial species encompassing commensals and pathogens with the ability to cause pulmonary disease in both immunocompetent and immunocompromised individuals. In contrast to Mycobacterium tuberculosis, which has seen a reduction in disease rates in developed countries, the incidence and prevalence of NTM disease is increasing. NTM are difficult to treat with standard antimicrobial regimens and may contain both virulence and antibiotic-resistance genes with potential for pathogenicity. With the advent of molecular techniques, it has been elucidated that these organisms do not reside in isolation and are rather part of a complex milieu of microorganisms within the host lung microbiome. Over the last decade, studies have highlighted the impact of the microbiome on host immunity, metabolism and cell-cell communication. This recognition of a broader community raises the possibility that the microbiome may disrupt the balance between infection and disease. Additionally, NTM disease progression and antimicrobial therapy may affect the healthy steady state of the host and function of the microbiome, contributing to further dysbiosis and clinical deterioration. There have been limited studies assessing how NTM may influence the relationship between microbiome and host. In this review, we highlight available studies about NTM and the microbiome, postulate on virulence mechanisms by which these microorganisms communicate and discuss implications for treatment.

Solutions to improve the latent tuberculosis Cascade of Care in Ghana: a longitudinal impact assessment.

BACKGROUND: Loss of patients in the latent tuberculosis infection (LTBI) cascade of care is a major barrier to LTBI management. We evaluated the impact and acceptability of local solutions implemented to strengthen LTBI management of household contacts (HHCs) at an outpatient clinic in Ghana. METHODS: Local solutions to improve LTBI management were informed by a baseline evaluation of the LTBI cascade and questionnaires administered to index patients, HHCs, and health care workers at the study site in Offinso, Ghana. Solutions aimed to reduce patient costs and improve knowledge. We evaluated the impact and acceptability of the solutions. Specific objectives were to: 1) Compare the proportion of eligible HHCs completing each step in the LTBI cascade of care before and after solution implementation; 2) Compare knowledge, attitude, and practices (KAP) before and after solution implementation, based on responses of patients and health care workers (HCW) to structured questionnaires; 3) Evaluate patient and HCW acceptability of solutions using information obtained from these questionnaires. RESULTS: Pre and Post-Solution LTBI Cascades included 58 and 125 HHCs, respectively. Before implementation, 39% of expected < 5-year-old HHCs and 66% of ≥5-year-old HHCs were identified. None completed any further cascade steps. Post implementation, the proportion of eligible HHCs who completed identification, assessment, evaluation, and treatment initiation increased for HHCs < 5 to 94, 100, 82, 100%, respectively, and for HHCs ≥5 to 96, 69, 67, 100%, respectively. Pre and Post-Solutions questionnaires were completed by 80 and 95 respondents, respectively. Study participants most frequently mentioned financial support and education as the solutions that supported LTBI management. CONCLUSION: Implementation of locally selected solutions was associated with an increase in the proportion of HHCs completing all steps in the LTBI cascade. Tuberculosis programs should consider prioritizing financial support, such as payment for chest x-rays, to support LTBI cascade completion.

The mTST - An mHealth approach for training and quality assurance of tuberculin skin test administration and reading.

BACKGROUND: The Tuberculin Skin Test (TST) is a relatively simple test for detecting latent tuberculosis infection (LTBI) but requires regular quality assurance to ensure proper technique for administration and reading. The objective of this study was to estimate the accuracy and reproducibility of an mhealth approach (the mTST) to measure the size of swelling immediately following TST administration (TST injection bleb) and after 48-72 hours (TST induration). METHODS: Five non-clinical and one clinical reviewer measured the size of TST injection blebs, and TST indurations using smartphone acquired photos of sites of TST administration and readings in patients, or saline injections in volunteers. The reference standard was the onsite measurement (measured by an experienced TB nurse) of the actual TST injection bleb, or induration. Agreement of reviewers' measurements with the reference standard, as well as agreement within and between reviewers, was estimated using Cohen's kappa coefficient. RESULTS: Using the mTST method to assess bleb size in 64 photos of different TST injections, agreement between reviewers, and the reference standard was very good to excellent (κ ranged from 0.75 to 0.87), and within-reviewer reproducibility of readings was excellent (κ ranged from 0.86 to 0.96). Using the mTST method to assess TST induration in 72 photos, reviewers were able to detect no induration (<5mm) and induration of 15mm or greater with accuracy of 95% and 92% respectively, but accuracy was only 20% and 77% for reactions of 5-9mm and 10-14mm respectively. CONCLUSION: The mTST approach appears to be a reliable tool to assess TST administration. The mTST approach was accurate to read indurations of 0-4mm or 15+mm, but less accurate for reactions of 5-14mm. We believe the mTST approach could be useful for training and quality assurance in locations where on-site supervision is not possible.

Using a quality improvement approach to improve care for latent tuberculosis infection.

INTRODUCTION: Latent tuberculosis infection (LTBI) management is recognized as a key component of the World Health Organization End Tuberculosis Strategy. The term 'cascade of care in LTBI' has recently been used to refer to the process of LTBI management from identification of persons who may have LTBI to completion of treatment. Large gaps throughout the LTBI cascade of care have been identified. Areas covered: We have reviewed quality improvement (QI) as a potential approach for systematically improving gaps within the LTBI cascade of care. QI principles and approaches were reviewed, as well as the determinants of losses and evidence for solutions (interventions) within the LTBI cascade of care. An example of QI application in LTBI management is described. Expert commentary: Improving LTBI care at the magnitude required to reach the End TB Strategy goals will require systematic and context specific improvements at all steps in the cascade of care in LTBI. A continuous QI approach based on systems thinking, use of locally gathered data, and an iterative learning process can facilitate the process required to make the necessary improvements.