Drug-resistant tuberculosis treatments, the case for a phase III platform trial.

Most phase III trials in drug-resistant tuberculosis have either been underpowered to quantify differences in microbiological endpoints or have taken up to a decade to complete. Composite primary endpoints, dominated by differences in treatment discontinuation and regimen changes, may mask important differences in treatment failure and relapse. Although new regimens for drug-resistant tuberculosis appear very effective, resistance to new drugs is emerging rapidly. There is a need for shorter, safer and more tolerable regimens, including those active against bedaquiline-resistant tuberculosis. Transitioning from multiple regimen A versus regimen B trials to a single large phase III platform trial would accelerate the acquisition of robust estimates of relative efficacy and safety. Further efficiencies could be achieved by adopting modern adaptive platform designs. Collaboration among trialists, affected community representatives, funders and regulators is essential for developing such a phase III platform trial for drug-resistant tuberculosis treatment regimens.

La majorité des essais de phase III relatifs à la tuberculose pharmacorésistante soit n'étaient pas assez puissants pour quantifier les fluctuations au niveau des critères microbiologiques, soit étaient trop longs, se poursuivant parfois pendant dix ans. Les critères primaires composites, dominés par des différences dans l'interruption du traitement et les changements de schéma, pourraient dissimuler d'importantes variations en termes d'échec thérapeutique et de rechute. Bien que les nouveaux traitements contre la tuberculose pharmacorésistante semblent très efficaces, la résistance aux nouveaux médicaments évolue rapidement. Il est donc nécessaire d'opter pour des traitements plus courts, plus sûrs et mieux tolérés, y compris ceux actifs contre la tuberculose résistant à la bédaquiline. Délaisser la multitude d'essais opposant un schéma de traitement A à un schéma de traitement B pour se diriger vers un unique essai plateforme de phase III de grande envergure permettrait d'obtenir plus vite des estimations solides concernant l'innocuité et l'efficacité relative. En outre, adopter des modèles de plateforme modernes et adaptatifs contribuerait à de meilleures performances. Enfin, la collaboration entre investigateurs, représentants des communautés concernées, bailleurs de fonds et organismes de réglementation est essentielle à l'élaboration de ce type d'essai plateforme de phase III sur les traitements contre la tuberculose pharmacorésistante.

La mayoría de los ensayos en fase III sobre tuberculosis resistente a los fármacos no ha tenido la potencia suficiente para cuantificar diferencias en los criterios de valoración microbiológicos o ha tardado hasta una década en completarse. Los criterios de valoración principales compuestos, dominados por las diferencias en la interrupción del tratamiento y los cambios de régimen, pueden ocultar diferencias importantes en el fracaso del tratamiento y la recaída. Aunque los nuevos regímenes de tratamiento para la tuberculosis resistente a los fármacos parecen muy eficaces, la resistencia a los nuevos fármacos está apareciendo rápidamente. Se necesitan regímenes de tratamiento más cortos, seguros y tolerables, incluidos los activos contra la tuberculosis resistente a la bedaquilina. La transición de múltiples ensayos de régimen A frente a régimen B a un único gran ensayo de plataforma en fase III aceleraría la obtención de estimaciones sólidas de la eficacia y seguridad relativas. Podrían lograrse mayores eficiencias si se adoptaran diseños de plataforma adaptativos modernos. La colaboración entre los autores de los ensayos, los representantes de las comunidades afectadas, los financiadores y los reguladores es esencial para desarrollar un ensayo de plataforma en fase III de este tipo para los regímenes de tratamiento de la tuberculosis resistente a los fármacos.

Improving 1-Year Mortality Following Intensive Care Unit Admission in Adults with HIV: A 20-Year Observational Study.

BACKGROUND: Despite widespread use of combination antiretroviral therapy, people with HIV (PWH) continue to have an increased risk of admission to and mortality in the intensive care unit (ICU). Mortality risk after hospital discharge is not well described. Using retrospective data on adult PWH (≥18 years) admitted to ICU from 2000-2019 in an HIV-referral centre, we describe trends in 1-year mortality after ICU admission. METHODS: One-year mortality was calculated from index ICU admission to date of death; with follow-up right-censored at day 365 for people remaining alive at 1 year, or day 7 after ICU discharge if lost-to-follow-up after hospital discharge. Cox regression was used to describe the association with calendar year before and after adjustment for patient characteristics (age, sex, Acute Physiology and Chronic Health Evaluation II [APACHE II] score, CD4+ T-cell count, and recent HIV diagnosis) at ICU admission. Analyses were additionally restricted to those discharged alive from ICU using a left-truncated design, with further adjustment for respiratory failure at ICU admission in these analyses. RESULTS: Two hundred and twenty-one PWH were admitted to ICU (72% male, median [interquartile range] age 45 [38-53] years) of whom 108 died within 1-year (cumulative 1-year survival: 50%). Overall, the hazard of 1-year mortality was decreased by 10% per year (crude hazard ratio (HR): 0.90 (95% confidence interval: 0.87-0.93)); the association was reduced to 7% per year (adjusted HR: 0.93 (0.89-0.98)) after adjustment. Conclusions were similar among the subset of 136 patients discharged alive (unadjusted: 0.91 (0.84-0.98); adjusted 0.92 (0.84, 1.02)). CONCLUSIONS: Between 2000 and 2019, 1-year mortality after ICU admission declined at this ICU. Our findings highlight the need for multi-centre studies and the importance of continued engagement in care after hospital discharge among PWH.

Forgiveness Is the Attribute of the Strong: Nonadherence and Regimen Shortening in Drug-sensitive Tuberculosis.

Rationale: "Forgiveness" charts the ability of a drug or regimen to withstand nonadherence without negative clinical consequences. Objectives: We aimed to determine the influence of regimen length, regimen drugs, and dosing, and when during treatment nonadherence occurs on the forgiveness of antituberculosis regimens. Methods: Using data from three randomized controlled trials comparing experimental 4-month regimens for drug-sensitive tuberculosis with the standard 6-month regimen, we used generalized linear models to examine how the risk of a negative composite outcome changed as dose-taking decreased. The percentage of doses taken and the absolute number of doses missed were calculated during the intensive and continuation phases of treatment, and overall. A mediation analysis was undertaken to determine how much the association between intensive phase dose-taking and the negative composite outcome was mediated through continuation phase dose-taking. Measurements and Main Results: Forgiveness of the 4- and 6-month regimens did not differ for any treatment period. Importantly, 4-month regimens were no less forgiving of small numbers of absolute missed doses than the 6-month regimen (e.g., for 3-7 missed doses vs. no missed doses [baseline], 6-month regimen adjusted risk ratio 1.65 [95% confidence interval, 0.80-3.41] and 4-month regimens 1.80 [1.33-2.45]). No 4-month regimen was conclusively more forgiving than another. We found evidence of mediation by continuation phase dose-taking on the intensive phase dose-taking and negative composite outcome relationship. Conclusions: With the current appetite for, and progress toward, shorter drug-sensitive tuberculosis regimens worldwide, we offer reassurance that shorter regimens are not necessarily less forgiving of nonadherence. Given the importance of continuation phase adherence, patient support during this period should not be neglected.

The roles of neutrophils in non-tuberculous mycobacterial pulmonary disease.

Non-tuberculous Mycobacterial Pulmonary Disease (NTM-PD) is an increasingly recognised global health issue. Studies have suggested that neutrophils may play an important role in controlling NTM infection and contribute to protective immune responses within the early phase of infection. However, these cells are also adversely associated with disease progression and exacerbation and can contribute to pathology, for example in the development of bronchiectasis. In this review, we discuss the key findings and latest evidence regarding the diverse functions of neutrophils in NTM infection. First, we focus on studies that implicate neutrophils in the early response to NTM infection and the evidence reporting neutrophils' capability to kill NTM. Next, we present an overview of the positive and negative effects that characterise the bidirectional relationship between neutrophils and adaptive immunity. We consider the pathological role of neutrophils in driving the clinical phenotype of NTM-PD including bronchiectasis. Finally, we highlight the current promising treatments in development targeting neutrophils in airways diseases. Clearly, more insights on the roles of neutrophils in NTM-PD are needed in order to inform both preventative strategies and host-directed therapy for these important infections.

Local and Systemic Nail Plate Abnormalities: A Clinical Review.

Nail disorders are often difficult to recognize and diagnose because of the subtlety of their presentation and their shared overlapping features that are common to several conditions. Experientially, this is further complicated by the fact that specific training on diagnosis of nail pathologies varies substantially across most residency programs and for a majority of medical and surgical specialties. To distinguish these presentations from true, potentially deleterious nail disorders, clinicians should have familiarity with the most commonly occurring nail pathologies and their associations, and use a systematic approach when examining or evaluating alterations in the nails. In the present study, we review the most common clinical disorders affecting the nail apparatus.

Estimating the risk of mortality attributable to recent late HIV diagnosis following admission to the intensive care unit: A single-centre observational cohort study.

OBJECTIVES: Despite improvements in survival of people with HIV admitted to the intensive care unit (ICU), late diagnosis continues to contribute to in-ICU mortality. We quantify the population attributable fraction (PAF) of in-ICU mortality for recent late diagnosis among people with HIV admitted to a London ICU. METHODS: Index ICU admissions among people with HIV were considered from 2000 to 2019. Recent late diagnosis was a CD4 T-cell count < 350 cells/µL and/or AIDS-defining illness at/within 6 months prior to ICU admission. Univariate comparisons were conducted using Wilcoxon rank-sum/Cochran-Armitage/χ2 /Fisher's exact tests. We used Poisson regression (robust standard errors) to estimate unadjusted/adjusted (age, sex, calendar year of ICU admission) risk ratios (RRs) and regression standardization to estimate the PAF. RESULTS: In all, 207 index admissions were included [median (interquartile range) age: 46 (38-53) years; 72% male]; 58 (28%) had a recent late diagnosis, all of whom had a CD4 count < 350 cells/µL, and 95% had advanced HIV (CD4 count < 200 cells/µL and/or AIDS at admission) as compared with 57% of those who did not have a recent late diagnosis (p < 0.001). In-ICU mortality was 27% (55/207); 38% versus 22% in those who did and did not have a recent late diagnosis, respectively (p = 0.02). Recent late diagnosis was independently associated with increased in-ICU mortality risk (adjusted RR = 1.75) (95% confidence interval: 1.05-2.91), with 17.08% (16.04-18.12%) of deaths being attributable to this. CONCLUSIONS: There is a need for improved public health efforts focused on HIV testing and reporting of late diagnosis to better understand potentially missed opportunities for earlier HIV diagnosis in healthcare services.

Comparative assessment of viral dynamic models for SARS-CoV-2 for pharmacodynamic assessment in early treatment trials.

Pharmacometric analyses of time series viral load data may detect drug effects with greater power than approaches using single time points. Because SARS-CoV-2 viral load rapidly rises and then falls, viral dynamic models have been used. We compared different modelling approaches when analysing Phase II-type viral dynamic data. Using two SARS-CoV-2 datasets of viral load starting within 7 days of symptoms, we fitted the slope-intercept exponential decay (SI), reduced target cell limited (rTCL), target cell limited (TCL) and TCL with eclipse phase (TCLE) models using nlmixr. Model performance was assessed via Bayesian information criterion (BIC), visual predictive checks (VPCs), goodness-of-fit plots, and parameter precision. The most complex (TCLE) model had the highest BIC for both datasets. The estimated viral decline rate was similar for all models except the TCL model for dataset A with a higher rate (median [range] day-1 : dataset A; 0.63 [0.56-1.84]; dataset B: 0.81 [0.74-0.85]). Our findings suggest simple models should be considered during pharmacodynamic model development.

'Long-COVID': a cross-sectional study of persisting symptoms, biomarker and imaging abnormalities following hospitalisation for COVID-19.

Large numbers of people are being discharged from hospital following COVID-19 without assessment of recovery. In 384 patients (mean age 59.9 years; 62% male) followed a median 54 days post discharge, 53% reported persistent breathlessness, 34% cough and 69% fatigue. 14.6% had depression. In those discharged with elevated biomarkers, 30.1% and 9.5% had persistently elevated d-dimer and C reactive protein, respectively. 38% of chest radiographs remained abnormal with 9% deteriorating. Systematic follow-up after hospitalisation with COVID-19 identifies the trajectory of physical and psychological symptom burden, recovery of blood biomarkers and imaging which could be used to inform the need for rehabilitation and/or further investigation.

Descriptive account of 18 adults with known HIV infection hospitalised with SARS-CoV-2 infection.

OBJECTIVE: To report on the clinical characteristics and outcome of 18 people living with HIV (PLWH) hospitalised with SARS-CoV-2 infection in a London teaching hospital. METHODS: The hospital notes of 18 PLWH hospitalised with SARS-CoV-2 infection were retrospectively reviewed alongside data concerning their HIV demographics from an established HIV Database. RESULTS: The majority (16/18) had positive PCR swabs for SARS-CoV-2, and two had negative swabs but typical COVID-19 imaging and history. Most were male (14/18, 78%), median age 63 years (range 47-77 years). Two-thirds were migrants, nine (50%) of Black, Asian and minority ethnicity (BAME). All were diagnosed with HIV for many years (range 8-31 years), and all had an undetectable HIV viral load (<40 copies/mL). The median CD4 prior to admission was 439 (IQR 239-651), and 10/16 (63%) had a CD4 nadir below 200 cells/mm3. Almost all (17/18) had been diagnosed with at least one comorbidity associated with SARS-CoV-2 prior to admission. 3/18 patients died. None received mechanical ventilation. Hospital stay and clinical course did not appear prolonged (median 9 days). CONCLUSIONS: Our data suggest that PLWH may not necessarily have prolonged or complex admissions to hospital when compared with the general hospital and national population admitted with COVID-19. Many had low nadir CD4 counts and potentially impaired functional immune restoration. The PLWH group was younger than generally reported for COVID-19, and the majority were male with multiple complex comorbidities. These patients had frequent contact with hospital settings increasing potential for nosocomial acquisition and increased risk of severe COVID-19.

Quantitative IFN-γ Release Assay and Tuberculin Skin Test Results to Predict Incident Tuberculosis. A Prospective Cohort Study.

Rationale: Development of diagnostic tools with improved predictive value for tuberculosis (TB) is a global research priority.Objectives: We evaluated whether implementing higher diagnostic thresholds than currently recommended for QuantiFERON Gold-in-Tube (QFT-GIT), T-SPOT.TB, and the tuberculin skin test (TST) might improve prediction of incident TB.Methods: Follow-up of a UK cohort of 9,610 adult TB contacts and recent migrants was extended by relinkage to national TB surveillance records (median follow-up 4.7 yr). Incidence rates and rate ratios, sensitivities, specificities, and predictive values for incident TB were calculated according to ordinal strata for quantitative results of QFT-GIT, T-SPOT.TB, and TST (with adjustment for prior bacillus Calmette-Guérin [BCG] vaccination).Measurements and Main Results: For all tests, incidence rates and rate ratios increased with the magnitude of the test result (P < 0.0001). Over 3 years' follow-up, there was a modest increase in positive predictive value with the higher thresholds (3.0% for QFT-GIT ≥0.35 IU/ml vs. 3.6% for ≥4.00 IU/ml; 3.4% for T-SPOT.TB ≥5 spots vs. 5.0% for ≥50 spots; and 3.1% for BCG-adjusted TST ≥5 mm vs. 4.3% for ≥15 mm). As thresholds increased, sensitivity to detect incident TB waned for all tests (61.0% for QFT-GIT ≥0.35 IU/ml vs. 23.2% for ≥4.00 IU/ml; 65.4% for T-SPOT.TB ≥5 spots vs. 27.2% for ≥50 spots; 69.7% for BCG-adjusted TST ≥5 mm vs. 28.1% for ≥15 mm).Conclusions: Implementation of higher thresholds for QFT-GIT, T-SPOT.TB, and TST modestly increases positive predictive value for incident TB, but markedly reduces sensitivity. Novel biomarkers or validated multivariable risk algorithms are required to improve prediction of incident TB.

Effectiveness of BCG Vaccination Against Mycobacterium tuberculosis Infection in Adults: A Cross-sectional Analysis of a UK-Based Cohort.

BACKGROUND: BCG appears to reduce acquisition of Mycobacterium tuberculosis infection in children, measured using interferon-gamma release assays (IGRAs). We explored whether BCG vaccination continues to be associated with decreased prevalence of M. tuberculosis infection in adults. METHODS: We conducted a cross-sectional analysis of data from adult contacts of tuberculosis cases participating in a UK cohort study. Vaccine effectiveness (VE) of BCG, ascertained based on presence of a scar or vaccination history, against latent tuberculosis infection (LTBI), measured via IGRA, was assessed using multivariable logistic regression. The effects of age at BCG and time since vaccination were also explored. RESULTS: Of 3453 recent tuberculosis contacts, 27.5% had LTBI. There was strong evidence of an association between BCG and LTBI (adjusted odds ratio = 0.70; 95% confidence interval, .56-.87; P = .0017) yielding a VE of 30%. VE declined with time since vaccination but there was evidence that LTBI prevalence was lower amongst vaccinated individuals even >20 years after vaccination, compared with nonvaccinated participants. CONCLUSIONS: BCG is associated with lower prevalence of LTBI in adult contacts of tuberculosis. These results contribute to growing evidence that suggests BCG may protect against M. tuberculosis infection as well as disease. This has implications for immunization programs, vaccine development, and tuberculosis control efforts worldwide. CLINICAL TRIALS REGISTRATION: NCT01162265.

Blood Transcriptomic Stratification of Short-term Risk in Contacts of Tuberculosis.

BACKGROUND: The highest risk of tuberculosis arises in the first few months after exposure. We reasoned that this risk reflects incipient disease among tuberculosis contacts. Blood transcriptional biomarkers of tuberculosis may predate clinical diagnosis, suggesting they offer improved sensitivity to detect subclinical incipient disease. Therefore, we sought to test the hypothesis that refined blood transcriptional biomarkers of active tuberculosis will improve stratification of short-term disease risk in tuberculosis contacts. METHODS: We combined analysis of previously published blood transcriptomic data with new data from a prospective human immunodeficiency virus (HIV)-negative UK cohort of 333 tuberculosis contacts. We used stability selection as an alternative computational approach to identify an optimal signature for short-term risk of active tuberculosis and evaluated its predictive value in independent cohorts. RESULTS: In a previously published HIV-negative South African case-control study of patients with asymptomatic Mycobacterium tuberculosis infection, a novel 3-gene transcriptional signature comprising BATF2, GBP5, and SCARF1 achieved a positive predictive value (PPV) of 23% for progression to active tuberculosis within 90 days. In a new UK cohort of 333 HIV-negative tuberculosis contacts with a median follow-up of 346 days, this signature achieved a PPV of 50% (95% confidence interval [CI], 15.7-84.3) and negative predictive value of 99.3% (95% CI, 97.5-99.9). By comparison, peripheral blood interferon gamma release assays in the same cohort achieved a PPV of 5.6% (95% CI, 2.1-11.8). CONCLUSIONS: This blood transcriptional signature provides unprecedented opportunities to target therapy among tuberculosis contacts with greatest risk of incident disease.

Smartphone-enabled video-observed versus directly observed treatment for tuberculosis: a multicentre, analyst-blinded, randomised, controlled superiority trial.

BACKGROUND: Directly observed treatment (DOT) has been the standard of care for tuberculosis since the early 1990s, but it is inconvenient for patients and service providers. Video-observed therapy (VOT) has been conditionally recommended by WHO as an alternative to DOT. We tested whether levels of treatment observation were improved with VOT. METHODS: We did a multicentre, analyst-blinded, randomised controlled superiority trial in 22 clinics in England (UK). Eligible participants were patients aged at least 16 years with active pulmonary or non-pulmonary tuberculosis who were eligible for DOT according to local guidance. Exclusion criteria included patients who did not have access to charging a smartphone. We randomly assigned participants to either VOT (daily remote observation using a smartphone app) or DOT (observations done three to five times per week in the home, community, or clinic settings). Randomisation was done by the SealedEnvelope service using minimisation. DOT involved treatment observation by a health-care or lay worker, with any remaining daily doses self-administered. VOT was provided by a centralised service in London. Patients were trained to record and send videos of every dose ingested 7 days per week using a smartphone app. Trained treatment observers viewed these videos through a password-protected website. Patients were also encouraged to report adverse drug events on the videos. Smartphones and data plans were provided free of charge by study investigators. DOT or VOT observation records were completed by observers until treatment or study end. The primary outcome was completion of 80% or more scheduled treatment observations over the first 2 months following enrolment. Intention-to-treat (ITT) and restricted (including only patients completing at least 1 week of observation on allocated arm) analyses were done. Superiority was determined by a 15% difference in the proportion of patients with the primary outcome (60% vs 75%). This trial is registered with the International Standard Randomised Controlled Trials Number registry, number ISRCTN26184967. FINDINGS: Between Sept 1, 2014, and Oct 1, 2016, we randomly assigned 226 patients; 112 to VOT and 114 to DOT. Overall, 131 (58%) patients had a history of homelessness, imprisonment, drug use, alcohol problems or mental health problems. In the ITT analysis, 78 (70%) of 112 patients on VOT achieved ≥80% scheduled observations successfully completed during the first 2 months compared with 35 (31%) of 114 on DOT (adjusted odds ratio [OR] 5·48, 95% CI 3·10-9·68; p<0·0001). In the restricted analysis, 78 (77%) of 101 patients on VOT achieved the primary outcome compared with 35 (63%) of 56 on DOT (adjusted OR 2·52; 95% CI 1·17-5·54; p=0·017). Stomach pain, nausea, and vomiting were the most common adverse events reported (in 16 [14%] of 112 on VOT and nine [8%] of 114 on DOT). INTERPRETATION: VOT was a more effective approach to observation of tuberculosis treatment than DOT. VOT is likely to be preferable to DOT for many patients across a broad range of settings, providing a more acceptable, effective, and cheaper option for supervision of daily and multiple daily doses than DOT. FUNDING: National Institute for Health Research.

Systematic evaluation and external validation of 22 prognostic models among hospitalised adults with COVID-19: an observational cohort study.

The number of proposed prognostic models for coronavirus disease 2019 (COVID-19) is growing rapidly, but it is unknown whether any are suitable for widespread clinical implementation.We independently externally validated the performance of candidate prognostic models, identified through a living systematic review, among consecutive adults admitted to hospital with a final diagnosis of COVID-19. We reconstructed candidate models as per original descriptions and evaluated performance for their original intended outcomes using predictors measured at the time of admission. We assessed discrimination, calibration and net benefit, compared to the default strategies of treating all and no patients, and against the most discriminating predictors in univariable analyses.We tested 22 candidate prognostic models among 411 participants with COVID-19, of whom 180 (43.8%) and 115 (28.0%) met the endpoints of clinical deterioration and mortality, respectively. Highest areas under receiver operating characteristic (AUROC) curves were achieved by the NEWS2 score for prediction of deterioration over 24 h (0.78, 95% CI 0.73-0.83), and a novel model for prediction of deterioration <14 days from admission (0.78, 95% CI 0.74-0.82). The most discriminating univariable predictors were admission oxygen saturation on room air for in-hospital deterioration (AUROC 0.76, 95% CI 0.71-0.81), and age for in-hospital mortality (AUROC 0.76, 95% CI 0.71-0.81). No prognostic model demonstrated consistently higher net benefit than these univariable predictors, across a range of threshold probabilities.Admission oxygen saturation on room air and patient age are strong predictors of deterioration and mortality among hospitalised adults with COVID-19, respectively. None of the prognostic models evaluated here offered incremental value for patient stratification to these univariable predictors.

Carprofen elicits pleiotropic mechanisms of bactericidal action with the potential to reverse antimicrobial drug resistance in tuberculosis.

BACKGROUND: The rise of antimicrobial drug resistance in Mycobacterium tuberculosis coupled with the shortage of new antibiotics has elevated TB to a major global health priority. Repurposing drugs developed or used for other conditions has gained special attention in the current scenario of accelerated drug development for several global infectious diseases. In a similar effort, previous studies revealed that carprofen, a non-steroidal anti-inflammatory drug, selectively inhibited the growth of replicating, non-replicating and MDR clinical isolates of M. tuberculosis. OBJECTIVES: We aimed to reveal the whole-cell phenotypic and transcriptomic effects of carprofen in mycobacteria. METHODS: Integrative molecular and microbiological approaches such as resazurin microtitre plate assay, high-throughput spot-culture growth inhibition assay, whole-cell efflux inhibition, biofilm inhibition and microarray analyses were performed. Analogues of carprofen were also synthesized and assessed for their antimycobacterial activity. RESULTS: Carprofen was found to be a bactericidal drug that inhibited mycobacterial drug efflux mechanisms. It also restricted mycobacterial biofilm growth. Transcriptome profiling revealed that carprofen likely acts by targeting respiration through the disruption of membrane potential. The pleiotropic nature of carprofen's anti-TB action may explain why spontaneous drug-resistant mutants could not be isolated in practice. CONCLUSIONS: This immunomodulatory drug and its chemical analogues have the potential to reverse TB antimicrobial drug resistance, offering a swift path to clinical trials of novel TB drug combinations.

Anticipating the impact of the COVID-19 pandemic on TB patients and TB control programmes.

The COVID-19 pandemic has currently overtaken every other health issue throughout the world. There are numerous ways in which this will impact existing public health issues. Here we reflect on the interactions between COVID-19 and tuberculosis (TB), which still ranks as the leading cause of death from a single infectious disease globally. There may be grave consequences for existing and undiagnosed TB patients globally, particularly in low and middle income countries (LMICs) where TB is endemic and health services poorly equipped. TB control programmes will be strained due to diversion of resources, and an inevitable loss of health system focus, such that some activities cannot or will not be prioritised. This is likely to lead to a reduction in quality of TB care and worse outcomes. Further, TB patients often have underlying co-morbidities and lung damage that may make them prone to more severe COVID-19. The symptoms of TB and COVID-19 can be similar, with for example cough and fever. Not only can this create diagnostic confusion, but it could worsen the stigmatization of TB patients especially in LMICs, given the fear of COVID-19. Children with TB are a vulnerable group especially likely to suffer as part of the "collateral damage". There will be a confounding of symptoms and epidemiological data through co-infection, as happens already with TB-HIV, and this will require unpicking. Lessons for COVID-19 could be learned from the vast experience of running global TB control programmes, while the astonishingly rapid and relatively well co-ordinated response to COVID-19 demonstrates how existing programmes could be significantly improved.

Diabetes mellitus and latent tuberculosis infection: baseline analysis of a large UK cohort.

We conducted a cross-sectional analysis of baseline data from a UK cohort study which enrolled participants at risk of latent tuberculosis infection (LTBI, defined as a positive result for either of the two interferon gamma release assays). Binomial regression with a log link was used to estimate crude and adjusted prevalence ratios (PRs) and 95% CIs for the relationship between diabetes mellitus (DM) and LTBI. Adjusted for age, sex, ethnicity, body mass index and the presence of other immunocompromising conditions, DM was associated with a 15% higher prevalence of LTBI (adjusted PR=1.15, 95% CI 1.02 to 1.30, p=0.025). TRIAL REGISTRATION NUMBER: PREDICT is registered on clinicaltrials.gov (NCT01162265).

Fluoroquinolones and isoniazid-resistant tuberculosis: implications for the 2018 WHO guidance.

INTRODUCTION: 2018 World Health Organization (WHO) guidelines for the treatment of isoniazid (H)-resistant (Hr) tuberculosis recommend a four-drug regimen: rifampicin (R), ethambutol (E), pyrazinamide (Z) and levofloxacin (Lfx), with or without H ([H]RZE-Lfx). This is used once Hr is known, such that patients complete 6 months of Lfx (≥6[H]RZE-6Lfx). This cohort study assessed the impact of fluoroquinolones (Fq) on treatment effectiveness, accounting for Hr mutations and degree of phenotypic resistance. METHODS: This was a retrospective cohort study of 626 Hr tuberculosis patients notified in London, 2009-2013. Regimens were described and logistic regression undertaken of the association between regimen and negative regimen-specific outcomes (broadly, death due to tuberculosis, treatment failure or disease recurrence). RESULTS: Of 594 individuals with regimen information, 330 (55.6%) were treated with (H)RfZE (Rf=rifamycins) and 211 (35.5%) with (H)RfZE-Fq. The median overall treatment period was 11.9 months and median Z duration 2.1 months. In a univariable logistic regression model comparing (H)RfZE with and without Fqs, there was no difference in the odds of a negative regimen-specific outcome (baseline (H)RfZE, cluster-specific odds ratio 1.05 (95% CI 0.60-1.82), p=0.87; cluster NHS trust). Results varied minimally in a multivariable model. This odds ratio dropped (0.57, 95% CI 0.14-2.28) when Hr genotype was included, but this analysis lacked power (p=0.42). CONCLUSIONS: In a high-income setting, we found a 12-month (H)RfZE regimen with a short Z duration to be similarly effective for Hr tuberculosis with or without a Fq. This regimen may result in fewer adverse events than the WHO recommendations.

New drugs to treat difficult tuberculous and nontuberculous mycobacterial pulmonary disease.

PURPOSE OF REVIEW: Treatment of drug-sensitive tuberculosis (TB) is effective, whereas that of multidrug-resistant and extensively drug-resistant TB as well as nontuberculous mycobacterial (NTM) disease are less so. Therapy in general requires good adherence to potentially toxic drug regimens over prolonged periods. Poor adherence is associated with resistance development and poor outcome. This review will present promising new treatments, both new drugs and regimens, for difficult mycobacterial pulmonary infections. RECENT FINDINGS: A number of new and repurposed drugs including bedaquiline, delamanid, pretomanid, linezolid and clofazimine, and drug regimens, such as the The Evaluation of a Standard Treatment Regimen of Anti-tuberculosis Drugs for Patients With MDR-TB (STREAM) trial regimens, are currently progressing from basic research through clinical trials.

High prevalence of latent tuberculosis and bloodborne virus infection in a homeless population.

INTRODUCTION: Urban homeless populations in the UK have been shown to have high rates of active tuberculosis, but less is known about the prevalence of latent tuberculosis infection (LTBI). This study aimed to estimate the prevalence of LTBI among individuals using homeless hostels in London. METHODS: We performed a cross-sectional survey with outcome follow-up in homeless hostels in London. Our primary outcome was prevalence of LTBI. Recruitment for the study took place between May 2011 and June 2013. To estimate an LTBI prevalence of 10% with 95% CIs between 8% and 13%, we required 500 participants. RESULTS: 491/804 (61.1%) individuals agreed to be screened. The prevalence of LTBI was 16.5% (81/491; 95% CI 13.2 to 19.8). In UK-born individuals, a history of incarceration was associated with increased risk of LTBI (OR 3.49; 95% CI 1.10 to 11.04; P=0.018) after adjusting for age, length of time spent homeless and illicit drug use. Of the three subjects who met English treatment guidelines for LTBI at the time of the study, none engaged with services after referral for treatment. Prevalence of past hepatitis B infection was 10.4% (51/489; 95% CI 7.7 to 13.1), and 59.5% (291/489; 95% CI 55.1 to 63.9) of individuals were non-immune. Prevalence of current hepatitis C infection was 10.4% (51/489; 95% CI 7.8 to 13.1). CONCLUSIONS: This study demonstrates the high prevalence of LTBI in homeless people in London and the associated poor engagement with care. There is a large unmet need for LTBI and hepatitis C infection treatment, and hepatitis B vaccination, in this group.