Post-tuberculosis mortality and morbidity: valuing the hidden epidemic

Cost-effectiveness of latent tuberculosis infection testing and treatment with 6-week regimen among key population in rural communities in China: a decision analysis study

PURPOSE

Several model studies suggested the implementation of latent tuberculosis infection (LTBI) testing and treatment could greatly reduce the incidence of tuberculosis (TB) and achieve the 2035 target of the "End TB" Strategy in China. The present study aimed to evaluate the cost-effectiveness of LTBI testing and TB preventive treatment among key population (≥ 50 years old) susceptible to TB at community level in China.

METHODS

A Markov model was developed to investigate the cost-effectiveness of LTBI testing using interferon gamma release assay (IGRA) and subsequent treatment with 6-month daily isoniazid regimen (6H) (as a standard regimen for comparison) or 6-week twice-weekly rifapentine and isoniazid regimen (6-week H2P2) in a cohort of 10,000 adults with an average initial age of 50 years.

RESULTS

In the base-case analysis, LTBI testing and treatment with 6H was dominated (i.e., more expensive with a lower quality-adjusted life year (QALY)) by LTBI testing and treatment with 6-week H2P2. LTBI testing and treatment with 6-week H2P2 was more effective than no intervention at a cost of $20,943.81 per QALY gained, which was below the willingness-to-pay (WTP) threshold of $24,211.84 per QALY gained in China. The one-way sensitivity analysis showed the change of LTBI prevalence was the parameter that most influenced the results of the incremental cost-effectiveness ratios (ICERs).

CONCLUSION

As estimated by a Markov model, LTBI testing and treatment with 6-week H2P2 was cost-saving compared with LTBI testing and treatment with 6H, and it was considered to be a cost-effective option for TB control in rural China.

Chronic Pulmonary Aspergillosis as a Considerable Complication in Post-Tuberculosis Lung Disease

Post-tuberculosis lung disease (PTLD) has only recently been put in the spotlight as a medical entity. Recent data suggest that up to 50% of tuberculosis (TB) patients are left with PTLD-related impairment after completion of TB treatment. The presence of residual cavities in the lung is the largest risk factor for the development of chronic pulmonary aspergillosis (CPA) globally. Diagnosis of CPA is based on four criteria including a typical radiological pattern, evidence of Aspergillus species, exclusion of alternative diagnosis, and a chronic course of disease. In this manuscript, we provide a narrative review on CPA as a serious complication for patients with PTLD.

Risk of dementia in survivors of active tuberculosis in Korea: A nationwide cohort study

BACKGROUND

Concern has been growing regarding post-tuberculosis (TB) morbidities, including neurologic and vascular comorbidities. However, the association between post-TB status and the risk of dementia has been evaluated in only few studies. Therefore, in the present study, the risk of dementia was investigated in a nationwide population-based cohort.

METHODS

Using the Korean National Health Insurance Service (KNHIS) database, this study included TB survivors (n = 50,182) and matched controls (n = 50,182) for age, sex, and year of index date. The risk of dementia was estimated using Cox proportional hazards regression, and stratified analyses for related factors were performed.

RESULTS

During a mean 3.5 years of follow-up, the incidence of dementia was 9.32 for Alzheimer disease and 1.17 for vascular dementia per 1000 person-years for TB survivors and 7.21 and 0.67, respectively, for matched controls. The overall risk of Alzheimer disease was 1.11 (95% confidence interval (CI) 1.03-1.20)-fold higher in TB survivors than in matched controls. For vascular dementia, 1.48 (95% CI 1.16-1.89)-fold higher risk was found in TB survivors than in matched controls. The strength of the association between TB and dementia was higher in CNS TB (aHR 1.76, 95% CI 1.18 -2.64) than non-CNS TB (aHR 1.11, 95% CI 1.05-1.19) compared to controls, especially for patients with vascular dementia (3.33, 95% CI 1.06-10.49).

CONCLUSION

TB survivors had a significantly higher risk of dementia than the general population.

The prevalence of pulmonary hypertension in post-tuberculosis and active tuberculosis populations: a systematic review and meta-analysis

BACKGROUND

The prevalence of tuberculosis (TB)-associated pulmonary hypertension (PH) has not previously been quantified, resulting in an underappreciated burden of disease. We aimed to estimate the prevalence of PH in post-TB and active TB populations.

METHODS

In this systematic review and meta-analysis, we searched PubMed/Medline, Cochrane Library, EBSCOhost, Scopus, African Journals Online and Google Scholar, with no language restriction, for available literature published after 1950. Eligible studies described adult participants (≥16 years), with documented evidence of active or prior TB, diagnosed with PH. Study quality was assessed using a risk of bias tool specifically developed for prevalence studies. Aggregate prevalence estimates with 95% confidence intervals were synthesised using a random-effects meta-analysis model, incorporating the Freeman-Tukey transformation. Subgroup analysis was conducted to ascertain prevalence estimates in specific patient populations.

RESULTS

We identified 1452 unique records, of which 34 met our inclusion criteria. 23 studies, with an acceptable risk of bias and where PH was diagnosed at right heart catheterisation or echocardiography, were included in the meta-analysis. In post-TB studies (14/23), the prevalence of PH was 67.0% (95% CI 50.8-81.4) in patients with chronic respiratory failure, 42.4% (95% CI 31.3-54.0) in hospitalised or symptomatic patients and 6.3% (95% CI 2.3-11.8) in nonhealthcare-seeking outpatients (I2=96%). There was a lower estimated prevalence of PH in studies of populations with active TB (9.4%, 95% CI 6.3-13.0), I2=84%).

CONCLUSION

Our results highlight the significant burden of PH in post-TB and active TB populations. We emphasise the need for increased recognition of TB-associated PH and additional high-quality prevalence data.

In-kind nutritional supplementation for household contacts of persons with tuberculosis would be cost-effective for reducing tuberculosis incidence and mortality in India: a modeling study

Background

Undernutrition is the leading cause of tuberculosis (TB) globally, but nutritional interventions are often considered cost prohibitive. The RATIONS study demonstrated that nutritional support provided to household contacts of persons with TB can reduce TB incidence. However, the long-term cost-effectiveness of this intervention is unclear.

Methods

We assessed the cost-effectiveness of a RATIONS-style intervention (daily 750 kcal dietary supplementation and multi-micronutrient tablet). Using a Markov state transition model we simulated TB incidence, treatment, and TB-attributable mortality among household contacts receiving the RATIONS intervention, as compared to no nutritional support. We calculated health outcomes (TB cases, TB deaths, and disability-adjusted life years [DALYs]) over the lifetime of intervention recipients and assessed costs from government and societal perspectives. We tested the robustness of results to parameter changes via deterministic and probabilistic sensitivity analysis.

Findings

Over two years, household contacts receiving the RATIONS intervention would experience 39% (95% uncertainty interval (UI): 23-52) fewer TB cases and 59% (95% UI: 44-69) fewer TB deaths. The intervention was estimated to avert 13,775 (95% UI: 9036-20,199) TB DALYs over the lifetime of the study cohort comprising 100,000 household contacts and was cost-effective from both government (incremental cost-effectiveness ratio: $229 per DALY averted [95% UI: 133-387]) and societal perspectives ($184 per DALY averted [95% UI: 83-344]). The results were most sensitive to the cost of the nutritional supplement.

Interpretation

Prompt nutritional support for household contacts of persons with TB disease would be cost-effective in reducing TB incidence and mortality in India.

Summary

Undernutrition is the leading cause of tuberculosis in India. Using a Markov state-transition model, we found that food baskets for household contacts of persons with tuberculosis would be cost-effective in reducing tuberculosis incidence and mortality in India.

Research in context

Evidence before this study: Undernutrition is the leading risk factor for TB worldwide. Recently, the RATIONS study demonstrated a roughly 40% reduction in incident TB among household contacts who received in-kind macronutrient and micronutrient supplementation. Added value of this study: Although the RATIONS study demonstrated a dramatic reduction in incident TB, it is unclear if nutritional interventions to prevent TB are cost-effective. Previously, only one cost-effectiveness analysis of nutritional interventions for household contacts has been published. Due to lack of published data, that study had to make assumptions regarding the impact of nutritional interventions on TB incidence and mortality. In this study, we conducted an economic evaluation of a RATIONS-style intervention to reduce incident TB and mortality in India using observed data. Implications of all the available evidence: In-kind nutritional supplementation for household contacts of individuals with TB disease would be cost-effective in reducing incident TB and TB mortality, particularly if TB programs leverage economies of scale to bring down the cost of the nutritional intervention.

Impaired lung function in adolescents with pulmonary tuberculosis during treatment and following treatment completion

Background

Little is known about post-tuberculosis lung disease in adolescents. We prospectively assessed lung function in adolescents with microbiologically confirmed pulmonary tuberculosis during treatment and after treatment completion.

Methods

In a prospective study, we enrolled adolescents diagnosed with microbiologically confirmed tuberculosis and healthy tuberculosis-exposed household controls, between October 2020 and July 2021 in Cape Town, South Africa. Spirometry, plethysmography, diffusion capacity lung function tests and 6-min walking test (6MWT) were completed according to international guidelines 2 months into treatment and following treatment completion. Abnormal lung function was defined as abnormal spirometry (z-score < -1.64 for forced expiratory volume in 1 s (FEV1) and/or forced vital capacity (FVC) and/or FEV1/FVC), plethysmography (total lung capacity (TLC) < 80% of predicted, residual volume over TLC of >45%) and/or diffusion capacity (DLCO z-score < -1.64).

Findings

One-hundred adolescents were enrolled; 50 (50%) with tuberculosis and 50 (50%) healthy tuberculosis-exposed controls. Of the 50 adolescents with tuberculosis, ten had multidrug-resistant tuberculosis. Mean age of the group was 14.9 years (SD 2.7), 6 (6.0%) were living with HIV and 9 (9.0%) were previously treated for tuberculosis. Lung function improved over time; during treatment abnormal lung function was found in 76% of adolescents with tuberculosis, compared to 65% after treatment completion. Spirometry indices were lower in adolescents with tuberculosis compared to controls, both at 2 months and after treatment completion. Plethysmography in adolescents with tuberculosis showed that air-trapping was more common during treatment than in controls (12% vs 0%, respectively, p = 0.017); which improved following treatment completion. Adolescents with tuberculosis both during and after treatment completion walked a shorter distance than controls.

Interpretation

Adolescents with tuberculosis have impaired lung function even after treatment completion. It is crucial to include adolescents in trials on the prevention and treatment of tuberculosis-associated respiratory morbidity.

Funding

EDCTP, National Institute of Health, Medical Research Council, BMBF.

Factors associated with mortality in HIV-TB co-infected patients during and after the course of TB treatment in high-burden settings, Mumbai, India: A cohort analysis

BACKGROUND

Knowledge of factors associated with TB mortality during treatment and post treatment will help us develop better monitoring and implementation strategies for TB control. We designed the present study to examine the factors associated with mortality in HIV-TB co-infected patients during and after the course of TB treatment.

METHODS

This study is a cohort analysis of secondary data collected from 1804 HIV-TB co-infected individuals from 16 anti-retroviral therapy (ART) centres affiliated with the Mumbai Districts AIDS Control Society, Mumbai, India. We used Kaplan Meier survival curves and hazard ratios to estimate the mortality in patients.

RESULTS

The overall mortality rate in this cohort was 1.14 per 100 per month. The mortality proportion was 18% (95% CI: 16.1%, 20.1%) during treatment and 10.6% (95% CI: 8.9%, 12.5%) in the post-treatment period. Mortality was significantly higher in those with a CD4 count 0-200 cells/mm3 (HR: 3.04, 95% CI: 2.13, 4.15; p < 0.001), and in patients who were ART naïve and referred to the ART centre with a diagnosis of TB (HR: 1.39, 95% CI: 1.06, 1.82; p = 0.016). Mortality was also significantly higher in the first 6 months after initiation of ART (HR: 1.36, 95% CI: 1.06, 1.75; p = 0.016). A decrease in the CD4 counts from initial levels at start of TB treatment to end of TB treatment was associated with higher mortality in the post-treatment period.

DISCUSSION

The overall mortality remains high; early identification of TB and HIV disease, and use of rapid point of care tests for diagnosis of TB are needed across all health care facilities. Post-treatment follow-up and monitoring is important in HIV-TB co-infected patients, and post-treatment mortality should also be considered as one of the indicators for successful TB control programmes.

Risk factors and biomarkers for post-tuberculosis lung damage in a Chinese cohort of male smokers and non-smokers: protocol for a prospective observational study

INTRODUCTION

Post-tuberculosis lung damage (PTLD) refers to the residual pulmonary impairment following the completion of antituberculosis (TB) therapy, characterised by persistent respiratory symptoms and abnormal pulmonary function. The risk factors and biomarkers for PTLD have been scarcely investigated. More importantly, whether and to what extent cigarette smoking is involved in PTLD remain to be known.

METHODS AND ANALYSIS

This prospective observational study will enrol 400 male smoking or non-smoking patients aged 25-65 years, with newly confirmed active TB between 2022 and 2024, from the Department of Respiratory and Critical Care Medicine at Peking University Third Hospital and the Tuberculosis Department at Beijing Geriatric Hospital. Because females rarely smoke in China, we will enrol only males in this study. Demographic data, smoking history and amount, clinical symptoms, lung function, and chest CT findings will be prospectively collected. Respiratory questionnaires, lung function measurements and chest CT examinations will be performed immediately after, and 1 year, 2 years and 3 years after the completion of TB treatment. Peripheral blood samples will be obtained at baseline and at the end of anti-TB therapy, and a Luminex xMAP-based multiplex immunoassay will be used to measure inflammatory mediators and cytokines in serum. The collected data will be analysed to determine the incidence and factors/biomarkers of PTLD according to smoking status.

ETHICS AND DISSEMINATION

The study was approved by the Ethics Committee of Peking University Third Hospital (approval number: (2022)271-03; approval date: 8 June 2022). The research results will be disseminated through scientific and medical conferences and will be published in an academic journal.

TRIAL REGISTRATION NUMBER

NCT04966052.

Detection of serum Aspergillus-specific IgM and IgG antibody levels for the diagnosis of chronic pulmonary aspergillosis developed in patients with tuberculosis

Chronic pulmonary aspergillosis (CPA) is common among individuals with underlying lung diseases. The clinical manifestations of CPA include systemic symptoms (e.g., weight loss, fatigue, fever), chronic productive cough, chest discomfort, and occasional haemoptysis, which are similar to the manifestations of pulmonary tuberculosis (PTB) and are often misdiagnosed as PTB. Considering the striking similarities between CPA and PTB in clinical manifestations and imaging features, more specific microbiological and serological detections are needed for a definitive diagnosis. This study aimed to explore the clinical characteristics of CPA in TB as well as the diagnostic significance of Aspergillus-specific IgG and Aspergillus-specific IgM.A total of 140 patients diagnosed with TB by culture between December 2017 and February 2019 were included. Enrolled patients were categorized into two groups (CPA group and non-CPA group) according to CPA diagnostic criteria. All collected specimens were subjected to Aspergillus-specific IgG and IgM detection testing.The median concentration of Aspergillus-specific IgG in the CPA group (211.04 AU/ml) was significantly higher than that in the non-CPA group (77.88 AU/ml) (Z value - 6.397, P < 0.001). The sensitivity and specificity of Aspergillus-specific IgG for CPA diagnosis were 81.82% and 72.97%, respectively. In the chronic cavitary pulmonary aspergillosis (CCPA) group, the IgG positivity rate (≥ 120 AU/ml) was 96.2%, which was 21.4% in the non-CCPA patients (P < 0.001).The detection of Aspergillus-specific IgG serological changes is feasible and facilitates reliable differentiation between Aspergillus and Mycobacterium tuberculosis infection. However, Aspergillus-specific IgM has limited diagnostic value, with unsatisfactory sensitivity results.

Post-tuberculosis lung disease and chronic obstructive pulmonary disease

ABSTRACT

The burden of chronic airway diseases, including chronic obstructive pulmonary disease (COPD), continues to increase, especially in low- and middle-income countries. Post-tuberculosis lung disease (PTLD) is characterized by chronic lung changes after the "cure" of pulmonary tuberculosis (TB), which may be associated with the pathogenesis of COPD. However, data on its prevalence, clinical manifestations, computed tomography features, patterns of lung function impairment, and influencing factors are limited. The pathogenic mechanisms underlying PTLD remain to be elucidated. This review summarizes the recent advances in PTLD and TB-associated COPD. Research is urgently needed both for the prevention and management of PTLD.

New tuberculosis vaccines in India: modelling the potential health and economic impacts of adolescent/adult vaccination with M72/AS01E and BCG-revaccination

BACKGROUND

India had an estimated 2.9 million tuberculosis cases and 506 thousand deaths in 2021. Novel vaccines effective in adolescents and adults could reduce this burden. M72/AS01E and BCG-revaccination have recently completed phase IIb trials and estimates of their population-level impact are needed. We estimated the potential health and economic impact of M72/AS01E and BCG-revaccination in India and investigated the impact of variation in vaccine characteristics and delivery strategies.

METHODS

We developed an age-stratified compartmental tuberculosis transmission model for India calibrated to country-specific epidemiology. We projected baseline epidemiology to 2050 assuming no-new-vaccine introduction, and M72/AS01E and BCG-revaccination scenarios over 2025-2050 exploring uncertainty in product characteristics (vaccine efficacy, mechanism of effect, infection status required for vaccine efficacy, duration of protection) and implementation (achieved vaccine coverage and ages targeted). We estimated reductions in tuberculosis cases and deaths by each scenario compared to the no-new-vaccine baseline, as well as costs and cost-effectiveness from health-system and societal perspectives.

RESULTS

M72/AS01E scenarios were predicted to avert 40% more tuberculosis cases and deaths by 2050 compared to BCG-revaccination scenarios. Cost-effectiveness ratios for M72/AS01E vaccines were around seven times higher than BCG-revaccination, but nearly all scenarios were cost-effective. The estimated average incremental cost was US$190 million for M72/AS01E and US$23 million for BCG-revaccination per year. Sources of uncertainty included whether M72/AS01E was efficacious in uninfected individuals at vaccination, and if BCG-revaccination could prevent disease.

CONCLUSIONS

M72/AS01E and BCG-revaccination could be impactful and cost-effective in India. However, there is great uncertainty in impact, especially given the unknowns surrounding the mechanism of effect and infection status required for vaccine efficacy. Greater investment in vaccine development and delivery is needed to resolve these unknowns in vaccine product characteristics.

Using a theory-informed approach to guide the initial development of a post-tuberculosis care package in British Columbia, Canada

BACKGROUND

The importance of addressing the long-term needs of tuberculosis (TB) survivors is gaining increasing attention. One promising approach to improving post-TB care is implementing a post-TB care package. With a specific focus on the perspectives of healthcare providers in British Columbia, Canada, this study aimed to (1) determine a set of components to be included in a post-TB care package, (2) explore barriers and facilitators influencing their implementation, and (3) propose potential solutions to overcome identified challenges.

METHODS

Employing a multi-method approach guided by the Theoretical Domains Framework, we first conducted virtual workshops with TB care providers and utilized a modified Delphi process to establish a preliminary list of care package components. Then, we surveyed healthcare providers using closed-ended, Likert-scale questions to identify implementation barriers and enablers. Lastly, we mapped the identified barriers and enablers to establish behaviour change techniques to identify possible solutions to overcome the challenges identified.

RESULTS

Eleven participants attended virtual workshops, and 23 of 51 (45.1%) healthcare providers completed questionnaires. Identified components of the post-TB care package included: 1. Linking people with TB to a primary care provider if they do not have one. 2. Referring people with pulmonary TB for an end-of-treatment chest x-ray and pulmonary function testing. 3. Referring people with TB who smoke to a smoking cessation specialist. 4. Sharing a one-page post-TB information sheet with the patient's primary care provider, including a summary of post-TB health concerns, complications, and recommendations to prioritize age-appropriate screening for cardiovascular disease, lung cancer, and depression. Survey results indicated that domain scores for 'environment, context, and resources' were the lowest, suggesting potential implementation barriers. Care navigation services to help individuals overcome health system barriers while transitioning from TB care, information leaflets, and checklists summarizing key post-TB health concerns for patients and healthcare providers to help facilitate discussions may help overcome the identified barriers.

CONCLUSION

Healthcare providers in British Columbia acknowledge that post-TB care is integral to comprehensive health care but are limited by time and resources. Care navigation services, a post-TB checklist, and patient information leaflets may help resolve some of these barriers.

Post-tuberculosis lung impairment: systematic review and meta-analysis of spirometry data from 14 621 people

BACKGROUND

A substantial proportion of tuberculosis patients remain with pulmonary symptoms and reduced physical capacity despite successful treatment. We performed a systematic review to analyse the burden of post-tuberculosis lung impairment measured by lung function testing.

METHODS

We searched the PubMed database for articles published between database inception and November 2020 and performed meta-analyses to estimate the prevalence, type and severity of lung impairment among drug-susceptible and multidrug-resistant tuberculosis survivors. Methodological quality of included studies was assessed using the Newcastle-Ottawa scale.

RESULTS

54 articles were included in this review. For subjects with former drug-susceptible tuberculosis, the combined estimated mean was 76.6% (95% CI 71.6-81.6) of predicted for forced expiratory volume in 1 s (FEV1) and 81.8% (95% CI 77.4-86.2) for forced vital capacity (FVC). In former patients with multidrug-resistant tuberculosis, it was 65.9% (95% CI 57.1-74.7) for FEV1 and 76.0% (95% CI 66.3-85.8) for FVC, respectively. The analysis of impairment types in former patients with drug-susceptible and multidrug-resistant tuberculosis showed that 22.0% versus 19.0% had obstructive, 23.0% versus 22.0% restrictive and 15.0% versus 43.0% had mixed impairment type, respectively. In the majority of studies, at least 10-15% of tuberculosis survivors had severe lung impairment.

CONCLUSIONS

This systematic review showed long-term abnormal spirometry results in a significant proportion of tuberculosis survivors.

Disease burden of tuberculosis and post-tuberculosis in Inner Mongolia, China, 2016-2018 - based on the disease burden of post-TB caused by COPD

BACKGROUND

Tuberculosis (TB) remains one of the most serious infectious diseases worldwide. China has the second highest TB burden globally, but existing studies have mostly neglected the post-tuberculosis (post-TB) disease burden. This study estimated the disease burden of TB and post-TB in Inner Mongolia, China, from 2016 to 2018.

METHODS

Population data were collected from TB Information Management System. Post-TB disease burden was defined as the burden caused by Chronic Obstructive Pulmonary Disease (COPD) occurring after patients with TB were cured. To estimate the incidence rate of TB, standardized mortality rate, life expectancy, and cause eliminated life expectancy, using descriptive epidemiological, abridged life table and cause eliminated life table. On this basis, the Disability-Adjusted Life Years (DALY), Years Lived with Disability (YLD) and Years of Life Lost (YLL) due to TB were further be estimated. The data were analyzed using Excel 2016 and SPSS 26.0. Joinpoint regression models were used to estimate the time and age trends of the disease burden of TB and post-TB.

RESULTS

The TB incidence in 2016, 2017, and 2018 was 41.65, 44.30, and 55.63/100,000, respectively. The standardized mortality in the same period was 0.58, 0.65, and 1.08/100,000, respectively. From 2016 to 2018, the total DALYs of TB and post-TB were 5923.33, 6258.03, and 8194.38 person-years, and the DALYs of post-TB from 2016 to 2018 were 1555.89, 1663.33, and 2042.43 person-years. Joinpoint regression showed that the DALYs rate increased yearly from 2016 to 2018, and the rate of males was higher than that of females. TB and post-TB DALYs rates showed a rising tendency with increasing age (AAPC values were 149.6% and 157.0%, respectively, P < 0.05), which was higher in the working-age population and elderly.

CONCLUSION

The disease burden of TB and post-TB was heavy and increased year by year in Inner Mongolia from 2016 to 2018. Compared with the youngster and females, working-age population and the elderly and males had a higher disease burden. Policymakers should be paid more attention to the patients' sustained lung injury after TB cured. There is a pressing need to identify more effective measures for reducing the burden of TB and post-TB of people, to improve their health and well-being.

The Long-Term Impact of Early-Life Tuberculosis Disease on Child Health: A Prospective Birth Cohort Study

Rationale: There is growing concern that post-tuberculosis disease (TB) sequelae and morbidity are substantial, but no studies have controlled for preexisting factors before disease. Whether children have post-TB morbidity is not well characterized. Objectives: To assess the effect of a TB diagnosis on wheezing episodes, lung function, and anthropometric measurements among children enrolled in a prospective birth cohort study in South Africa. Methods: We prospectively followed children from birth through 5 years for TB using diagnostic tests including chest radiography and repeated induced sputum sample testing with Xpert MTB/RIF and liquid culture. We longitudinally measured health outcomes including growth, wheezing, and lung function up to 5 years. Mixed-effects linear regression models were used to assess growth and lung function after TB. Poisson regression was used to assess risk of subsequent wheezing. Measurements and Main Results: Among 1,068 participants, 96 TB cases occurred (1,228 cases per 100,000 person-years [95% confidence interval (CI), 1,006-1,500]) occurred over 7,815 child-years of follow-up. TB was associated with lower length-for-age (-0.40 [95% CI, -0.68 to -0.11]), weight-for-age (-0.30 [95% CI, -0.59 to -0.01]), and body mass index (-0.54 [95% CI, -0.83 to -0.25]) z-scores at 5 years. Children developing TB were consistently more likely to wheeze regardless of the timing of TB. Children with diagnoses of TB between 0 and 1 year of age had reduced time to peak tidal expiratory flow over total expiratory time (-2.35% [95% CI, -4.86% to -0.17%]) and higher fractional exhaled nitric oxide (2.88 ppb [95% CI, 0.57-5.19 ppb]) at 5 years. Children with diagnoses of TB between 1 and 4 years of age had impaired Vt (-9.32 ml [95% CI, -14.89 to -3.75 ml]) and time to peak tidal expiratory flow over total expiratory time (-2.73% [95% CI, -5.45% to -0.01%]) at 5 years. Conclusions: Prevention of TB disease in the first few years of life may have substantial long-term benefits through childhood.

Drug resistant TB - latest developments in epidemiology, diagnostics and management

AIM

The aim of this review is to inform the reader on the latest developments in epidemiology, diagnostics and management.

EPIDEMIOLOGY

Drug-resistant Tuberculosis (DR-TB) continues to be a current global health threat, and is defined by higher morbidity and mortality, sequelae, higher cost and complexity. The WHO classifies drug-resistant TB into 5 categories: isoniazid-resistant TB, rifampicin resistant (RR)-TB and MDR-TB, (TB resistant to isoniazid and rifampicin), pre-extensively drug-resistant TB (pre-XDR-TB) which is MDR-TB with resistance to a fluoroquinolone and finally XDR-TB that is TB resistant to rifampicin, plus any fluoroquinolone, plus at least one further priority A drug (bedaquiline or linezolid). Of 500,000 estimated new cases of RR-TB in 2020, only 157 903 cases are notified. Only about a third of cases are detected and treated annually.

DIAGNOSTICS

Recently newer rapid diagnostic methods like the GeneXpert, whole genome sequencing and Myc-TB offer solutions for rapid detection of resistance.

TREATMENT

The availability of new TB drugs and shorter treatment regimens have been recommended for the management of DR-TB.

CONCLUSION

Despite advances in diagnostics and treatments we still have to find and treat two thirds of the drug resistant cases that go undetected and therefore go untreated each year. Control of TB and elimination will only occur if cases are detected, diagnosed and treated promptly.

Breathing Back Better! A State of the Art on the Benefits of Functional Evaluation and Rehabilitation of Post-Tuberculosis and Post-COVID Lungs

Currently, tuberculosis (TB) and COVID-19 account for substantial morbidity and mortality worldwide, not only during their acute phase, but also because of their sequelae. This scoping review aims to describe the specific aspects of post-TB and post-COVID (long-COVID-19) sequelae, and the implications for post-disease follow-up and rehabilitation. In particular, evidence on how to identify patients affected by sequelae is presented and discussed. A section of the review is dedicated to identifying patients eligible for pulmonary rehabilitation (PR), as not all patients with sequelae are eligible for PR. Components of PR are presented and discussed, as well as their effectiveness. Other essential components to implement comprehensive rehabilitation programmes such as counselling and health education of enrolled patients, evaluation of cost-effectiveness of PR and its impact on health systems as well as research priorities for the future are included in this scoping review.

TB morbidity estimates overlook the contribution of post-TB disability: evidence from urban Malawi

INTRODUCTION

Despite growing evidence of the long-term impact of tuberculosis (TB) on quality of life, Global Burden of Disease (GBD) estimates of TB-related disability-adjusted life years (DALYs) do not include post-TB morbidity, and evaluations of TB interventions typically assume treated patients return to pre-TB health. Using primary data, we estimate years of life lost due to disability (YLDs), years of life lost due to premature mortality (YLL) and DALYs associated with post-TB cardiorespiratory morbidity in a low-income country.

METHODS

Adults aged ≥15 years who had successfully completed treatment for drug-sensitive pulmonary TB in Blantyre, Malawi (February 2016-April 2017) were followed-up for 3 years with 6-monthly and 12-monthly study visits. In this secondary analysis, St George's Respiratory Questionnaire data were used to match patients to GBD cardiorespiratory health states and corresponding disability weights (DWs) at each visit. YLDs were calculated for the study period and estimated for remaining lifespan using Malawian life table life expectancies. YLL were estimated using study mortality data and aspirational life expectancies, and post-TB DALYs derived. Data were disaggregated by HIV status and gender.

RESULTS

At treatment completion, 222/403 (55.1%) participants met criteria for a cardiorespiratory DW, decreasing to 15.6% after 3 years, at which point two-thirds of the disability burden was experienced by women. Over 90% of projected lifetime-YLD were concentrated within the most severely affected 20% of survivors. Mean DWs in the 3 years post-treatment were 0.041 (HIV-) and 0.025 (HIV+), and beyond 3 years estimated as 0.025 (HIV-) and 0.010 (HIV+), compared with GBD DWs of 0.408 (HIV+) and 0.333 (HIV-) during active disease. Our results imply that the majority of TB-related morbidity occurs post-treatment.

CONCLUSION

TB-related DALYs are greatly underestimated by overlooking post-TB disability. The total disability burden of TB is likely undervalued by both GBD estimates and economic evaluations of interventions, particularly those aimed at early diagnosis and prevention.

Cost-effectiveness of short, oral treatment regimens for rifampicin resistant tuberculosis

Current options for treating tuberculosis (TB) that is resistant to rifampicin (RR-TB) are few, and regimens are often long and poorly tolerated. Following recent evidence from the TB-PRACTECAL trial countries are considering programmatic uptake of 6-month, all-oral treatment regimens. We used a Markov model to estimate the incremental cost-effectiveness of three regimens containing bedaquiline, pretomanid and linezolid (BPaL) with and without moxifloxacin (BPaLM) or clofazimine (BPaLC) compared with the current mix of long and short standard of care (SOC) regimens to treat RR-TB from the provider perspective in India, Georgia, Philippines, and South Africa. We estimated total costs (2019 USD) and disability-adjusted life years (DALYs) over a 20-year time horizon. Costs and DALYs were discounted at 3% in the base case. Parameter uncertainty was tested with univariate and probabilistic sensitivity analysis. We found that all three regimens would improve health outcomes and reduce costs compared with the current programmatic mix of long and short SOC regimens in all four countries. BPaL was the most cost-saving regimen in all countries, saving $112-$1,173 per person. BPaLM was the preferred regimen at a willingness to pay per DALY of 0.5 GDP per capita in all settings. Our findings indicate BPaL-based regimens are likely to be cost-saving and more effective than the current standard of care in a range of settings. Countries should consider programmatic uptake of BPaL-based regimens.

Lifetime burden of disease due to incident tuberculosis: a global reappraisal including post-tuberculosis sequelae

Background

Many individuals who survive tuberculosis disease face ongoing disability and elevated mortality risks. However, the impact of post-tuberculosis sequelae is generally omitted from policy analyses and disease burden estimates. We therefore estimated the global burden of tuberculosis, inclusive of post-tuberculosis morbidity and mortality.

Methods

We constructed a hypothetical cohort of individuals developing tuberculosis in 2019, including pulmonary and extrapulmonary disease. We simulated lifetime health outcomes for this cohort, stratified by country, age, sex, HIV status, and treatment status. We used disability-adjusted life-years (DALYs) to summarise fatal and non-fatal health losses attributable to tuberculosis, during the disease episode and afterwards. We estimated post-tuberculosis mortality and morbidity based on the decreased lung function caused by pulmonary tuberculosis disease.

Findings

Globally, we estimated 122 (95% uncertainty interval [UI] 98–151) million DALYs due to incident tuberculosis disease in 2019, with 58 (38–83) million DALYs attributed to post-tuberculosis sequelae, representing 47% (95% UI 37–57) of the total burden estimate. The increase in burden from post-tuberculosis varied substantially across countries and regions, driven largely by differences in estimated case fatality for the disease episode. We estimated 12·1 DALYs (95% UI 10·0–14·9) per incident tuberculosis case, of which 6·3 DALYs (5·6–7·0) were from the disease episode and 5·8 DALYs (3·8–8·3) were from post-tuberculosis. Per-case post-tuberculosis burden estimates were greater for younger individuals, and in countries with high incidence rates. The burden of post-tuberculosis was spread over the remaining lifetime of tuberculosis survivors, with almost a third of total DALYs (28%, 95% UI 23–34) accruing 15 or more years after incident tuberculosis.

Interpretation

Post-tuberculosis sequelae add substantially to the overall disease burden caused by tuberculosis. This hitherto unquantified burden has been omitted from most previous policy analyses. Future policy analyses and burden estimates should take better account of post-tuberculosis, to avoid the potential misallocation of funding, political attention, and research effort resulting from continued neglect of this issue.

Funding

National Institutes of Health.

Treatment outcome among Post TB obstructive airways diseases and COPD: A prospective cohort study

Context:

Post Tubercular Obstructive Airways Diseases (Post-TB OAD) is a sequela of Pulmonary TB but diseases progression may not same like Chronic Obstructive Pulmonary Diseases (COPD).

Aim:

To compare the frequency and severity of exacerbations, change of FEV1, frequency of hospitalization and mortality among COPD and post TB OAD patients.

Setting and Design:

Hospital-based prospective cohort study.

Methods and Material:

COPD cohort was diagnosed based on symptoms, history of exposure to risk factors and post bronchodilator FEV1/FVC ratio <70%. Post TB OAD cohort was diagnosed like COPD along with past history of Pulmonary TB. Both cohorts were followed up every 3-monthly intervals for up to 12 months.

Statistical Analysis:

Comparison of categorical variable was done by Chi-square test and continuous variable by unpaired t test. Longitudinal data of FEV1% were analyzed by repeated measure ANOVA test.

Results:

Totally, 68 patients with Post TB OAD and 66 COPD patients were taken into this study. The frequency of exacerbation (3.52 ± 1.84 verses 2.70 ± 1.37), number of severe exacerbation (56 verses 24) and frequency of hospitalization (1.37 ± 0.81 verses 0.97 ± 0.94) more seen in post-TB OAD cohort in compared to COPD cohort which is statistically significant. Mortality more seen in post-TB OAD group (14 verses 6). Rate of decline FEV1 per year more seen in Post-TB OAD (0.27 ± 0.28 lit verses 0.17 ± 0.26 liter) as compared to COPD. There was overall decreasing trend of FEV1% over period of 12 month but without any difference among two cohort.

Conclusion:

There was more in frequency of exacerbations, number of severe exacerbations, frequency of hospitalization and number of mortalities among post TB OAD compared to COPD.

Clinical standards for the assessment, management and rehabilitation of post-TB lung disease

BACKGROUND: Increasing evidence suggests that post-TB lung disease (PTLD) causes significant morbidity and mortality. The aim of these clinical standards is to provide guidance on the assessment and management of PTLD and the implementation of pulmonary rehabilitation (PR).METHODS: A panel of global experts in the field of TB care and PR was identified; 62 participated in a Delphi process. A 5-point Likert scale was used to score the initial ideas for standards and after several rounds of revision the document was approved (with 100% agreement).RESULTS: Five clinical standards were defined: Standard 1, to assess patients at the end of TB treatment for PTLD (with adaptation for children and specific settings/situations); Standard 2, to identify patients with PTLD for PR; Standard 3, tailoring the PR programme to patient needs and the local setting; Standard 4, to evaluate the effectiveness of PR; and Standard 5, to conduct education and counselling. Standard 6 addresses public health aspects of PTLD and outcomes due to PR.CONCLUSION: This is the first consensus-based set of Clinical Standards for PTLD. Our aim is to improve patient care and quality of life by guiding clinicians, programme managers and public health officers in planning and implementing adequate measures to assess and manage PTLD.

Cost effectiveness of three months of rifapentine and isoniazid for latent tuberculosis in Syrian refugees

Background

Latent Tuberculosis infection (LTBI) has a large global burden especially among refugees. We aimed to test the cost effectiveness of weekly rifapentine plus isoniazid for 3 months (3HP) versus nine months of daily isoniazid (INH-9) to treat LTBI in Syrian refugees residing in Turkey.

Methods

We used a Markov state transition model to estimate the incremental cost-effectiveness of 3HP relative to INH-9 using a simulated cohort of Syrian refugees. Both cost and effectiveness were assessed assuming that LTBI screening would be performed, with treatment of those who screen positive. Costs were measured in 2017 US dollars, and effectiveness was estimated as quality adjusted life years (QALYs) gained. An annual discount rate of 3% was applied to future costs and QALYs over the analytical time horizon of 20 years.

Results

Per 100 individuals screened at age 30 in the base case scenario, treating LTBI with 3HP rather than INH-9 resulted in a gain of 0.08 QALYs (95% uncertainty interval: -0.007, 0.221) and savings of $1421 ($483, $3478). Assuming a value of $100000 per QALY, the incremental net monetary benefit of 3HP was $9772 ($639, $24517). Findings were robust to sensitivity analyses except when treating older individuals.

Conclusions

3HP is likely to save costs and improve health compared to INH-9 when used for LTBI treatment among Syrian refugees in Turkey.

Quantifying the global number of tuberculosis survivors: a modelling study

BACKGROUND

People who survive tuberculosis face clinical and societal consequences after recovery, including increased risks of recurrent tuberculosis, premature death, reduced lung function, and ongoing stigma. To describe the size of this issue, we aimed to estimate the number of individuals who developed first-episode tuberculosis between 1980 and 2019, the number who survived to 2020, and the number who have been treated within the past 5 years or 2 years.

METHODS

In this modelling study, we estimated the number of people who survived treated tuberculosis using country-level WHO data on tuberculosis case notifications, excluding those who died during treatment. We estimated the number of individuals surviving untreated tuberculosis using the difference between WHO country-level incidence estimates and notifications, applying published age-stratified and HIV-stratified case fatality ratios. To estimate survival with time, post-tuberculosis life tables were developed for each country-year by use of UN World Population Prospects 2019 mortality rates and published post-tuberculosis mortality hazard ratios.

FINDINGS

Between 1980 and 2019, we estimate that 363 million people (95% uncertainty interval [UI] 287 million-438 million) developed tuberculosis, of whom 172 million (169 million-174 million) were treated. Individuals who developed tuberculosis between 1980 and 2019 had lived 3480 million life-years (95% UI 3040 million-3920 million) after tuberculosis by 2020, with survivors younger than 15 years at the time of tuberculosis development contributing 12% (95% UI 7-17) of these life-years. We estimate that 155 million tuberculosis survivors (95% UI 138 million-171 million) were alive in 2020, the largest proportion (47% [37-57]) of whom were in the WHO South-East Asia region. Of the tuberculosis survivors who were alive in 2020, we estimate that 18% (95% UI 16-20) were treated in the past 5 years and 8% (7-9) were treated in the past 2 years.

INTERPRETATION

The number of tuberculosis survivors alive in 2020 is more than ten times the estimated annual tuberculosis incidence. Interventions to alleviate respiratory morbidity, screen for and prevent recurrent tuberculosis, and reduce stigma should be immediately prioritised for recently treated tuberculosis survivors.

FUNDING

UK Medical Research Council, the UK Department for International Development, the National Institute for Health Research, and the European and Developing Countries Clinical Trials Partnership.

Post-tuberculosis airway disease: A population-based cohort study of people immigrating to British Columbia, Canada, 1985-2015

BACKGROUND

Current epidemiological evidence of post-TB airway disease is largely cross-sectional and derived from high-TB-incidence settings. We present the first cohort study of post-TB airway disease in a low-TB-incidence setting.

AIMS

(1) analyze the risk of airway disease by respiratory TB, (2) assess potential unmeasured confounding between TB and airway disease, and (3) investigate TB effect measure modification.

METHODS

A population-based cohort study using healthcare claims data for immigrants to British Columbia (BC), Canada, 1985-2015. Airway disease included chronic airway obstruction, asthma, bronchitis, bronchiolitis, and emphysema. Respiratory TB was defined from TB registry data. Cox proportional hazards (PH) regressions were used to analyze time-to-airway disease by respiratory TB. Sensitivity analyses included varying definitions of TB and airway disease. Potential unmeasured confounding by smoking was evaluated by E-value and hybrid least absolute shrinkage and selection operator (LASSO)-high-dimensional propensity score (hdPS).

FINDINGS

In our cohort (N = 1 005 328; n_TB=1141) there were 116 840 incident cases of airway disease during our 30-year study period (10.43 per 1,000 person-years of follow-up), with cumulative incidence of 42·5% among respiratory TB patients compared with 11·6% among non-TB controls. The covariate-adjusted hazard ratio (aHR) for airway disease by respiratory TB was 2·08 (95% CI: 1·91-2·28) with E-value=3·58. The LASSO-hdPS analysis produced aHR=2·26 (95% CI: 2·07-2·47).

INTERPRETATION

A twofold higher risk of airway disease was observed among immigrants diagnosed with respiratory TB, compared with non-TB controls, in a low-TB-incidence setting. Unmeasured confounding is unlikely to explain this relationship. Models of post-TB care are needed.

FUNDING

Canadian Institutes of Health Research.

Post-Tuberculosis Lung Disease: Clinical Review of an Under-Recognised Global Challenge

An estimated 58 million people have survived tuberculosis since 2000, yet many of them will suffer from post-tuberculosis lung disease (PTLD). PTLD results from a complex interplay between organism, host, and environmental factors and affects long-term respiratory health. PTLD is an overlapping spectrum of disorders that affects large and small airways (bronchiectasis and obstructive lung disease), lung parenchyma, pulmonary vasculature, and pleura and may be complicated by co-infection and haemoptysis. People affected by PTLD have shortened life expectancy and increased risk of recurrent tuberculosis, but predictors of long-term outcomes are not known. No data are available on PTLD in children and on impact throughout the life course. Risk-factors for PTLD include multiple episodes of tuberculosis, drug-resistant tuberculosis, delays in diagnosis, and possibly smoking. Due to a lack of controlled trials in this population, no evidence-based recommendations for the investigation and management of PTLD are currently available. Empirical expert opinion advocates pulmonary rehabilitation, smoking cessation, and vaccinations (pneumococcal and influenza). Exacerbations in PTLD remain both poorly understood and under-recognised. Among people with PTLD, the probability of tuberculosis recurrence must be balanced against other causes of symptom worsening. Unnecessary courses of repeated empiric anti-tuberculosis chemotherapy should be avoided. PTLD is an important contributor to the global burden of chronic lung disease. Advocacy is needed to increase recognition for PTLD and its associated economic, social, and psychological consequences and to better understand how PTLD sequelae could be mitigated. Research is urgently needed to inform policy to guide clinical decision-making and preventative strategies for PTLD.

The long term effect of pulmonary tuberculosis on income and employment in a low income, urban setting

Background

Mitigating the socioeconomic impact of tuberculosis (TB) is key to the WHO End TB Strategy. However, little known about socioeconomic well-being beyond TB-treatment completion. In this mixed-methods study, we describe socioeconomic outcomes after TB-disease in urban Blantyre, Malawi, and explore pathways and barriers to financial recovery.

Methods

Adults ≥15 years successfully completing treatment for a first episode of pulmonary TB under the National TB Control Programme were prospectively followed up for 12 months. Socioeconomic, income, occupation, health seeking and cost data were collected. Determinants and impacts of ongoing financial hardship were explored through illness narrative interviews with purposively selected participants.

Results

405 participants were recruited from February 2016 to April 2017. Median age was 35 years (IQR: 28–41), 67.9% (275/405) were male, and 60.6% (244/405) were HIV-positive. Employment and incomes were lowest at TB-treatment completion, with limited recovery in the following year: fewer people were in paid work (63.0% (232/368) vs 72.4% (293/405), p=0.006), median incomes were lower (US$44.13 (IQR: US$0–US$106.15) vs US$72.20 (IQR: US$26.71–US$173.29), p<0.001), and more patients were living in poverty (earning <US$1.90/day: 57.7% (211/366) vs 41.6% (166/399), p<0.001) 1 year after TB-treatment completion compared with before TB-disease onset. Half of the participants (50.5%, 184/368) reported ongoing dissaving (use of savings, selling assets, borrowing money) and 9.5% (35/368) reported school interruptions in the year after TB-treatment completion. Twenty-one participants completed in-depth interviews. Reported barriers to economic recovery included financial insecurity, challenges rebuilding business relationships, residual physical morbidity and stigma.

Conclusions

TB-affected households remain economically vulnerable even after TB-treatment completion, with limited recovery in income and employment, persistent financial strain requiring dissaving, and ongoing school interruptions. Measures of the economic impact of TB disease should include the post-TB period. Interventions to protect the long-term health and livelihoods of TB survivors must be explored.

Application of the Ilizarov technique for knee joint arthrodesis as a treatment for end-stage tuberculosis of the knee

Background

With the global determination to eliminate tuberculosis (TB), the treatment for end-stage TB of the knee joint is still a great clinical challenge. This study aims to retrospectively determine the clinical and radiographic outcomes after use of the Ilizarov technique for knee joint arthrodesis as a treatment for end-stage knee TB.

Methods

Twenty-six patients with end-stage knee TB treated by external fixation with the Ilizarov fixator between 2012 and 2017 were examined. Anti-TB drugs were administered preoperatively, intraoperatively, and postoperatively. Clinical and radiologic examinations were performed for comprehensive evaluations, and these include C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), flexion and valgus angle of the knee, leg-length discrepancy, and Lysholm score.

Results

Twenty-four patients were followed up for an average of 5.8 years (2.2–7 years). All patients achieved bone fusion within a mean of 6.4 months (4–16 months). The ESR and CRP concentrations were observed to return to normal within 5.1 ± 1.1 months postoperatively. There was no recurrence of TB. At last follow-up, the mean leg-length discrepancy was 2.7 ± 1.4 cm, and the mean alignment was 8.7 ± 2.6° flexion and 5.3 ± 1.0° valgus. No patient had a significant rotational deformity. The average Lysholm score was seen to improve significantly from 36.8 ± 18.4 preoperatively to 79.5 ± 5.9 at final follow-up (p < 0.0001).

Conclusion

This study has demonstrated that the Ilizarov technique for knee joint arthrodesis as a treatment of end-stage knee TB achieved promising outcomes with minimal complications.

The Growing Importance of Tuberculosis Preventive Therapy and How Research and Innovation Can Enhance Its Implementation on the Ground

Ending the tuberculosis (TB) epidemic by 2030 requires two key actions: rapid diagnosis and effective treatment of active TB and identification and treatment of latent TB infection to prevent progression to active disease. We introduce this perspective by documenting the growing importance of TB preventive therapy on the international agenda coupled with global data showing poor implementation of preventive activities in programmatic settings. We follow this with two principal objectives. The first is to examine implementation challenges around diagnosis and treatment of active TB. Within this, we include recent evidence about the continued morbidity and heightened mortality that persists after TB treatment is successfully completed, thus elevating the importance of TB preventive therapy. The second objective is to outline how current TB preventive therapy activities have been shaped and are managed and propose how these can be improved through research and innovation. This includes expanding and giving higher priority to certain high-risk groups including those with fibrotic lung lesions on chest X-ray, showcasing the need to develop and deploy new biomarkers to more accurately predict risk of disease and making shorter treatment regimens, especially with rifapentine-isoniazid, more user-friendly and widely available. Ending the TB epidemic requires not only cure of the disease but preventing it before it even begins.