Caring for Children with Drug-Resistant Tuberculosis

Risk factors associated with post-tuberculosis sequelae: a systematic review and meta-analysis

Background

Post-tuberculosis (TB) sequelae present a significant challenge in the management of TB survivors, often leading to persistent health issues even after successful treatment. Identifying risk factors associated with post-TB sequelae is important for improving outcomes and quality of life of TB survivors. This systematic review and meta-analysis aims to identify risk factors associated with long-term physical sequelae among TB survivors.

Methods

We systematically searched Medline, Embase, PROQUEST, and Scopus for studies on long-term physical sequelae among TB survivors up to December 12, 2023. The primary outcome of interest was to quantify risk factors of long-term physical sequelae (i.e., respiratory, hepatic, hearing, neurological, visual, renal, and musculoskeletal sequelae). We included all forms of TB patients who experienced long-term physical sequelae. We used narrative synthesis for risk factors reported once and random-effect meta-analysis for primary outcomes with two or more studies. Findings were presented with odds ratios (OR) and 95% confidence intervals (CI). Publication bias was assessed using funnel plots and Egger regression, and heterogeneity was examined with a Galbraith radial plot. The protocol was registered on Prospero (CRD42021250909).

Findings

A total of 73 articles from 28 countries representing 31,553 TB-treated patients were included in the narrative synthesis, with 64 of these studies included in the meta-analysis. Risk factors associated with post-TB lung sequelae include older age (OR = 1.62, 95% CI: 1.07-2.47), previous TB treatment history (OR = 3.43, 95% CI: 2.37-4.97), smoking (OR = 1.41, 95% CI: 1.09-1.83), alcohol consumption (OR = 1.84, 95% CI: 1.04-3.25), smear-positive pulmonary TB diagnosis (OR = 3.11, 95% CI: 1.77-6.44), and the presence of radiographic evidence of pulmonary lesions at the commencement of treatment (OR = 2.04, 95% CI: 1.07-3.87). Risk factors associated with post-TB liver injury included pre-existing hepatitis (OR = 2.41, 95% CI: 1.16-6.08), previous TB treatment (OR = 2.64, 95% CI: 1.22-6.67), hypo-albuminemia (OR = 2.10, 95% CI: 1.53-2.88), HIV co-infection (OR = 2.72, 95% CI: 1.66-4.46), and CD4 count <200 mm3 in HIV-infected individuals (OR = 2.03, 95%CI: 1.26-3.27). Risk factors associated with post-TB hearing loss include baseline hearing problems (OR = 1.72, 95% CI: 1.30-2.26), and HIV co-infection (OR = 3.02, 95% CI: 1.96-4.64).

Interpretation

This systematic review and meta-analysis found that long-term physical post-TB sequelae including respiratory, hepatic, and hearing impairment were associated with a range of socio-demographic, behavioral, and clinical factors. Identification of these risk factors will help to identify patients who will benefit from interventions to reduce the burden of suffering from post-TB treatment.

Funding

Healy Medical Research Raine Foundation, the Australian National Health and Medical Research Council, and Curtin University Higher Degree Research Scholarship fund the study.

Treatment of drug-resistant tuberculosis in children and young adolescents in Brazil

Introduction

Drug-resistant tuberculosis (DR-TB) is a global threat and a challenge for public health authorities worldwide. In children, the diagnosis is even more challenging and DR-TB is poorly described in the literature, as are its treatment outcomes. In this study, we aimed to describe the treatment of drug-resistant TB in children and young adolescents in Brazil.

Methods

A descriptive epidemiological study of treatment for DR-TB in children under 15 years of age in Brazil between 2013 and 2020. The primary data source was the Information System for Special Tuberculosis Treatments (SITE-TB). Categorical variables were analyzed using relative frequencies (%) and continuous variables by measures of central tendency to characterize the profile of the cases, namely: sociodemographic, clinical characteristics, procedures, tests performed and treatment success. In order to verify the distribution of cases, a spatial analysis was carried out based on the municipality where the cases resided.

Results

Between 2013 and 2020, 19,757 tuberculosis (TB) cases occurred in children aged <15 years in Brazil, and 46 cases of treatment for DR-TB were reported during the same period (annual average of 6 cases). Of these, 73.9% were aged 10-14, 65.2% were male, 4.3% were HIV+ and 43.3% were underweight (BMI<18.5) at the start of treatment. 17.4% had previous contact with TB, 69.6% had primary resistance, 47.8% multidrug resistance. The median duration of treatment was 15 months. DOT and standardized treatment regimen were performed in 52.2% of cases. Bacilloscopy was performed for 97.8% (57.8% positive); culture for 89.1% (75.6% positive), rapid molecular test for 73.9% with proven resistance to rifampicin in 55.8%. Susceptibility testing revealed resistance mainly to isoniazid (87.8%) and rifampicin (60.6%). 73.9% of cases were successfully treated and one death was reported. Cases were treated in 26 Brazilian municipalities, with the majority in Rio de Janeiro (15) and São Paulo (4).

Conclusion

DR-TB treatment was recorded in <1% of general TB cases in children and young adolescents, suggesting underreporting of drug-resistant cases in the country. Despite the low number of registered cases, the data reflect the situation of DR-TB in this population and describe important aspects of the problem, as the child needs comprehensive, individualized care, with support from different professionals. We recommend a strengthening of the country's referral services for the care of children with DR-TB so that surveillance and health care services can work together to identify and follow up cases.

A qualitative exploration of challenges in childhood TB patients identification and diagnosis in Bangladesh

Background

As childhood tuberculosis is difficult to identify and diagnose, the experiences of the caregivers and healthcare providers of childhood tuberculosis patients remain a potential area of study. This study aims to illustrate the challenges caregivers and healthcare providers encounter in identifying and diagnosing childhood tuberculosis in two sub-districts of Bangladesh.

Methods

We conducted semi-structured in-depth interviews with eight caregivers of childhood tuberculosis patients and key informant interviews with 36 healthcare providers from September 2020 to December 2020 from different levels of the tuberculosis control program in Keraniganj (with high childhood tuberculosis cases notification), Faridpur Sadar (with low childhood tuberculosis cases notification), and Dhaka city.

Results

There is a dearth of understanding among caregivers about childhood tuberculosis. Passive case finding process and focus on cough during community mobilisation contribute to the delay in childhood tuberculosis identification. The stigmatisation that caregivers anticipate and experience has an impact on their mental health and implies that there are misunderstandings about tuberculosis in the community. Furthermore, diagnostic dilemma among healthcare providers accounts for diagnosis delays. Some, but not all, institutions in different geographical locations provide free diagnostic tests and have GeneXpert devices.

Conclusions

Various factors, including caregivers' knowledge and experience, the process of case finding and community mobilization, healthcare providers' way of service provision and diagnosis, and the unavailability of required logistics at facilities challenge the identification and diagnosis of childhood tuberculosis that need to be minimized for childhood tuberculosis's early identification, diagnosis, treatment initiation, and successful completion of treatment. Awareness should also be raised in the community of childhood tuberculosis.

Advances of new drugs bedaquiline and delamanid in the treatment of multi-drug resistant tuberculosis in children

Tuberculosis (TB) is a major public health problem, with nearly 10 million new cases and millions of deaths each year. Around 10% of these cases are in children, but only a fraction receive proper diagnosis and treatment. The spread of drug-resistant (DR) strain of TB has made it difficult to control, with only 60% of patients responding to treatment. Multi-drug resistant TB (MDR-TB) is often undiagnosed in children due to lack of awareness or under-diagnosis, and the target for children's DR-TB treatment has only been met in 15% of goals. New medications such as bedaquiline and delamanid have been approved for treating DR-TB. However, due to age and weight differences, adults and children require different dosages. The availability of child-friendly formulations is limited by a lack of clinical data in children. This paper reviews the development history of these drugs, their mechanism of action, efficacy, safety potential problems and current use in treating DR-TB in children.

Trends and challenges of multi-drug resistance in childhood tuberculosis

Drug-resistant tuberculosis (DR-TB) in children is a growing global health concern, This review provides an overview of the current epidemiology of childhood TB and DR-TB, including prevalence, incidence, and mortality. We discuss the challenges in diagnosing TB and DR-TB in children and the limitations of current diagnostic tools. We summarize the challenges associated with treating multi-drug resistance TB in childhood, including limitations of current treatment options, drug adverse effects, prolonged regimens, and managing and monitoring during treatment. We highlight the urgent need for improved diagnosis and treatment of DR-TB in children. The treatment of children with multidrug-resistant tuberculosis will be expanded to include the evaluation of new drugs or new combinations of drugs. Basic research is needed to support the technological development of biomarkers to assess the phase of therapy, as well as the urgent need for improved diagnostic and treatment options.

Updates in Pediatric Tuberculosis in International Settings

Childhood tuberculosis (TB) has been underreported and underrepresented in TB statistics across the globe. Contributing factors include health system barriers, diagnostic barriers, and community barriers leading to an underdetected epidemic of childhood tuberculosis. Despite considerable progress in childhood TB management, there is a concerning gap in policy and practice in high-burden countries leading to missed opportunities for active case detection, early diagnosis and treatment of TB exposure, and infection and disease in children regardless of human immunodeficiency virus status. Bridging this gap requires multisectoral coordination and political commitment along with an eye to research and innovation with potential to scale.

Tuberculosis of the spine in children - does drug resistance affect surgical outcomes?

BACKGROUND CONTEXT

The emergence of drug resistance has complicated the management of spinal tuberculosis (TB). While it is well known that the medical management of drug-resistant spinal TB is more difficult, the surgical outcomes of the same have not been studied sufficiently, particularly in children.

PURPOSE

To analyze the surgical outcomes in a cohort of children treated for spinal TB, and to thus assess whether drug resistant (DR) disease is associated with poorer surgical outcomes.

STUDY DESIGN/SETTING

Retrospective observational study.

PATIENT SAMPLE

All children diagnosed and treated for tuberculous spondylodiscitis at a single center between January 2014 and June 2017.

OUTCOME MEASURES

Surgical outcomes in terms of neurological status and kyphosis angle at final follow-up, and complication rates.

METHODS

Radiographic and clinical data of children treated for spinal TB with minimum two-year follow-up were retrospectively analyzed. Data gathered included age, gender, level of spine affected, number of vertebrae involved, neurology (Frankel grade), microbiological reports, duration and type of anti-tuberculous therapy (ATT), details of Orthopaedic management and complications during treatment. In DR cases, the time from presentation to starting of second-line ATT was also assessed. Radiographs were reviewed to note the pre- and post-operative degree of kyphosis as well as the angle at final follow-up. Patients that developed major complications were compared statistically with those that did not.

RESULTS

Forty-one consecutive children (mean age 8.5 ± 4.2 years, 20 boys, 21 girls) were treated for spinal TB with a mean follow-up of 31.2 ± 6.4 months. Fifteen were managed conservatively, of which only one had DR-TB. Of the 26 managed surgically, 13 were managed with first-line ATT and 13 required second-line ATT. Of this latter group, eight had microbiologically proven drug resistance, whereas five were switched to second-line therapy presumptively because of failure to show an adequate response to first-line regimen. At last follow-up, all children had completed the prescribed course of ATT and had been declared cured. Neurological improvement was seen in all but one patient; and at last follow-up, 18 children were Frankel E, seven were Frankel D, and one was Frankel B. ¹The immediate post-operative Kyphosis angle averaged 24.38° ± 15.21°. However, six children showed a subsequent worsening of kyphosis, and the Kyphosis angle at last follow-up averaged 30.96° ± 23.92°. Five children had major complications requiring revision surgery; complications included wound dehiscence, vertebral collapse, screw pull-out and implant breakage. Significantly higher number of patients in the group with complications had required second-line ATT (p < .05).

CONCLUSIONS

In a cohort of children treated surgically for spinal tuberculosis, a higher complication rate, and thus poor surgical outcomes, were found to be associated with drug resistant disease.

Using Changes in Weight-for-Age z Score to Predict Effectiveness of Childhood Tuberculosis Therapy

BACKGROUND

International guidelines recommend monitoring weight as an indicator of therapeutic response in childhood tuberculosis (TB) disease. This recommendation is based on observations in adults. In the current study, we evaluated the association between weight change and treatment outcome, the accuracy of using weight change to predict regimen efficacy, and whether successfully treated children achieve catch-up weight gain.

METHODS

We enrolled children treated for drug-susceptible TB disease (group 1) and multidrug-resistant TB disease (group 2) in Peru. We calculated the change in weight-for-age z score (ΔWAZ) between baseline and the end of treatment months 2-5 for group 1, and between baseline and months 2-8 for group 2. We used logistic regression and generalized estimating equation models to evaluate the relationship between ΔWAZ and outcome. We plotted receiver operating characteristic curves to determine the accuracy of ΔWAZ for predicting treatment failure or death.

RESULTS

Groups 1 and 2 included 100 and 94 children, respectively. In logistic regression, lower ΔWAZ in months 3-5 and month 7 was associated with treatment failure or death in groups 1 and 2, respectively. In generalized estimating equation models, children in both groups who experienced treatment failure or death had lower ΔWAZ than successfully treated children. The ΔWAZ predicted treatment failure or death with 60%-90% sensitivity and 60%-86% specificity in months 2-5 for group 1 and months 7-8 for group 2. All successfully treated children-except group 2 participants with unknown microbiologic confirmation status-achieved catch-up weight gain.

CONCLUSIONS

Weight change early in therapy can predict the outcome of childhood TB treatment.

Diagnosis and Management of Multidrug-Resistant Tuberculosis in Children: A Practical Approach

Approximately 25,000 children develop multidrug-resistant (MDR) tuberculosis (TB) each year, but few of them are diagnosed and appropriately treated for MDR-TB. New diagnostic tools have improved our ability to diagnose children with bacteriologically confirmed TB earlier. However, the majority of childhood TB cases are not bacteriologically confirmed; therefore a high index of suspicion is needed, and taking a detailed history of contact with drug-resistant source cases and previous TB treatment is important to identify presumed MDR-TB cases. Treatment for MDR-TB is rapidly changing with the addition of new and repurposed drugs, the introduction of shorter regimens and the move towards injectable-free, all-oral MDR-TB treatment regimens. Children have been neglected in the introduction of the new drugs, but drug dosing and safety studies are now being completed. This article presents a practical approach in deciding which regimen to use in individual children in need of MDR-TB treatment. Outcomes in those treated are generally good, but only <5% of children with MDR-TB are currently diagnosed and appropriately treated. Diagnosing children with MDR-TB and getting them on to correct treatment regimens should now be our main focus.

Mycobacterial tuberculosis Enzyme Targets and their Inhibitors

Tuberculosis (TB) still continues to be a major killer disease worldwide. Unlike other bacteria Mycobacterium tuberculosis (Mtb) has the ability to become dormant within the host and to develop resistance. Hence efforts are being made to overcome these problems by searching for new antitubercular agents which may be useful in the treatment of multidrug-(MDR) and extensively drugresistant (XDR) M. tuberculosis and shortening the treatment time. The recent introduction of bedaquiline to treat MDR-TB and XDR-TB may improve the status of TB treatment. The target enzymes in anti-TB drug discovery programs play a key role, hence efforts have been made to review the work on molecules including antiTB drugs acting on different enzyme targets including ATP synthase, the target for bedaquiline. Literature searches have been carried out to find the different chemical molecules including drugs and their molecular targets responsible for their antitubercular activities in recent years. This review provides an overview of the chemical structures with their antitubercular activities and enzyme targets like InhA, ATP synthase, Lip Y, transmembrane transport protein large (MmpL3), and decaprenylphospho-β-D-ribofuranose 2-oxidase, (DprE1). The major focus has been on the new target ATP synthase. Such an attempt may be useful in designing new chemical entities (NCEs) for specific and multi-drug targeting against Mtb.

Tuberculosis in Children

Mycobacterium tuberculosis is the leading cause of death worldwide from a single bacterial pathogen. The World Health Organization estimates that annually 1 million children have tuberculosis (TB) disease and many more harbor a latent form. Accurate estimates are hindered by under-recognition and challenges in diagnosis. To date, an accurate diagnostic test to confirm TB in children does not exist. Treatment is lengthy but outcomes are generally favorable with timely initiation. With the End TB Strategy, there is an urgent need for improved diagnostics and treatment to prevent the unnecessary morbidity and mortality from TB in children.

Early Detection and Analysis of Children with Multidrug-Resistant Tuberculosis of the Spine

Study Design

Retrospective case series.

Purpose

The aim of the study is to report the clinical characteristics, early diagnosis, management, and outcome of children with multidrug-resistant (MDR) tubercular spondylodiscitis and to assess the early detection of rifampicin resistance using the Xpert MTB/ RIF assay.

Overview of Literature

MDR tuberculosis is on the rise, especially in developing countries. The incidence rate of MDR has been reported as 8.9% in children.

Methods

A retrospective study of children aged <15 years of age who were diagnosed and treated for MDR tuberculosis of the spine was conducted. Confirmed cases of MDR tuberculosis and patients who had completed at least 18 months of second-line antituberculous treatment (ATT) were included. Children were treated with ATT for 24 months according to drug-susceptibility-test results. Outcome measures included both clinical and radiological measures. Clinical measures included pain, neurological status, and return to school. Radiological measures included kyphosis correction and healing status.

Results

Six children with a mean age of 10 years were enrolled. The mean follow-up period was 12 months. All the children had previous history of treatment with first-line ATT, with an average of 13.6 months before presentation. Clinically, 50% (3/6 children) had psoas abscesses and 50% had spinal deformities. Radiologically, 50% (three of six children) had multicentric involvement. Three children underwent surgical decompression; two needed posterior stabilization with pedicle screws posteriorly followed by anterior column reconstruction. Early diagnosis of MDR was achieved in 83.3% (five of six children) with Xpert MTB/RIF assay. A total of 83.3% of the children were cured of the disease.

Conclusions

Xpert MTB/RIF assay confers the advantage of early detection, with initiation of MDR drugs within an average of 10.5 days from presentation. The cost of second-line ATT drugs was 30 times higher than that of first-line ATT.

ERS/ECDC Statement: European Union standards for tuberculosis care, 2017 update

The International Standards for Tuberculosis Care define the essential level of care for managing patients who have or are presumed to have tuberculosis, or are at increased risk of developing the disease. The resources and capacity in the European Union (EU) and the European Economic Area permit higher standards of care to secure quality and timely TB diagnosis, prevention and treatment. On this basis, the European Union Standards for Tuberculosis Care (ESTC) were published in 2012 as standards specifically tailored to the EU setting. Since the publication of the ESTC, new scientific evidence has become available and, therefore, the standards were reviewed and updated.A panel of international experts, led by a writing group from the European Respiratory Society (ERS) and the European Centre for Disease Prevention and Control (ECDC), updated the ESTC on the basis of new published evidence. The underlying principles of these patient-centred standards remain unchanged. The second edition of the ESTC includes 21 standards in the areas of diagnosis, treatment, HIV and comorbidities, and public health and prevention.The ESTC target clinicians and public health workers, provide an easy-to-use resource and act as a guide through all the required activities to ensure optimal diagnosis, treatment and prevention of TB.

Drug-Resistant tuberculosis - primary transmission and management

The DOTS strategy assisted global tuberculosis (TB) control, but was unable to prevent the emergence and spread of drug-resistant strains. Genomic evidence confirms the transmission of drug-resistant Mycobacterium tuberculosis strains in many different settings, indicative of epidemic spread. These findings emphasise the need for enhanced infection control measures in health care and congregate settings. Young children in TB endemic areas are particularly vulnerable. Although advances in TB drug and vaccine development are urgently needed, improved access to currently available preventive therapy and treatment for drug resistant TB could reduce the disease burden and adverse outcomes experienced by children. We review new insights into the transmission dynamics of drug resistant TB, the estimated disease burden in children and optimal management strategies to consider.

Tuberculosis in Children

Mycobacterium tuberculosis is the leading cause of death worldwide from a single bacterial pathogen. The World Health Organization estimates that annually 1 million children have tuberculosis (TB) disease and many more harbor a latent form. Accurate estimates are hindered by under-recognition and challenges in diagnosis. To date, an accurate diagnostic test to confirm TB in children does not exist. Treatment is lengthy but outcomes are generally favorable with timely initiation. With the End TB Strategy, there is an urgent need for improved diagnostics and treatment to prevent the unnecessary morbidity and mortality from TB in children.

New and Repurposed Drugs for Pediatric Multidrug-Resistant Tuberculosis. Practice-based Recommendations

It is estimated that 33,000 children develop multidrug-resistant tuberculosis (MDR-TB) each year. In spite of these numbers, children and adolescents have limited access to the new and repurposed MDR-TB drugs. There is also little clinical guidance for the use of these drugs and for the shorter MDR-TB regimen in the pediatric population. This is despite the fact that these drugs and regimens are associated with improved interim outcomes and acceptable safety profiles in adults. This review fills a gap in the pediatric MDR-TB literature by providing practice-based recommendations for the use of the new (delamanid and bedaquiline) and repurposed (linezolid and clofazimine) MDR-TB drugs and the new shorter MDR-TB regimen in children and adolescents.

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

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

Why the Convention on the Rights of the Child must become a guiding framework for the realization of the rights of children affected by tuberculosis

Background

Until recently, paediatric tuberculosis (TB) has been relatively neglected by the broader TB and the maternal and child health communities. Human rights-based approaches to children affected by TB could be powerful; however, awareness and application of such strategies is not widespread.

Discussion

We summarize the current challenges faced by children affected by TB, including: consideration of their family context; the limitations of preventive, diagnostic and treatment options; paucity of paediatric-specific research; failure in implementation of interventions; and stigma. We examine the articles of the Convention on the Rights of the Child (CRC) and relate them to childhood TB. Specifically, we focus on the five core principles of the CRC: children’s inherent right to life and States’ duties towards their survival and development; children’s right to enjoyment of the highest attainable standard of health; non-discrimination; best interests of the child; and respect for the views of the child. We highlight where children’s rights are violated and how a human rights-based approach should be used as a tool to help children affected by TB, particularly in light of the Sustainable Development Goals and their focus on universality and leaving no one behind.

Summary

The article aims to bridge the gap between those providing paediatric TB clinical care and conducting research, and those working in the fields of human rights policy and advocacy to promote a human rights-based approach for children affected by TB based upon the Convention on the Rights of the Child.

Drug-resistant tuberculosis and advances in the treatment of childhood tuberculosis

Over the last 10 years, interest in pediatric tuberculosis (TB) has increased dramatically, together with increased funding and research. We have a better understanding of the burden of childhood TB as well as a better idea of how to diagnose it. Our appreciation of pathophysiology is improved and with it investigators are beginning to consider pediatric TB as a heterogeneous entity, with different types and severity of disease being treated in different ways. There have been advances in how to treat both TB infection and TB disease caused by both drug-susceptible as well as drug-resistant organisms. Two completely novel drugs, bedaquiline and delamanid, have been developed, in addition to the use of older drugs that have been re-purposed. New regimens are being evaluated that have the potential to shorten treatment. Many of these drugs and regimens have first been investigated in adults with children an afterthought, but increasingly children are being considered at the outset and, in some instances studies are only conducted in children where pediatric-specific issues exist.

Clinical management of adults and children with multidrug-resistant and extensively drug-resistant tuberculosis

BACKGROUND

Globally there is a burgeoning epidemic of drug monoresistant tuberculosis (TB), multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB). Almost 20% of all TB strains worldwide are resistant to at least one major TB drug, including isoniazid. In several parts of the world there is an increasing incidence of MDR-TB, and alarmingly, almost a third of MDR-TB cases globally are resistant to either a fluoroquinolone or aminoglycoside. This trend cannot be ignored because drug-resistant TB is associated with greater morbidity compared to drug-susceptible TB, accounts for almost 25% of global TB mortality, is extremely costly to treat, consumes substantial portions of budgets allocated to national TB programmes in TB-endemic countries and is a major threat to healthcare workers, who are already in short supply in resource-poor settings. Even more worrying is the growing epidemic of resistance beyond XDR-TB, including resistance to newer drugs such as bedaquiline and delamanid, as well as the increasing prevalence of programmatically incurable TB in countries like South Africa, Russia, India and China. These developments threaten to reverse the gains already made against TB.

SOURCES

Articles related to MDR-TB and XDR-TB found on PubMed in all languages up to September 2016, published reviews, and files of the authors.

AIM AND CONTENT

To review the clinical management of adults and children with MDR- and XDR-TB with a particular emphasis on the utility of newer and repurposed drugs such as linezolid, bedaquiline and delamanid, as well as management of MDR- and XDR-TB in special situations such as in HIV-infected persons and in children.

IMPLICATIONS

This review informs on the prevention, diagnosis, and clinical management of MDR-TB and XDR-TB.

Adverse effects of oral second-line antituberculosis drugs in children

INTRODUCTION

Increasing numbers of children with drug-resistant tuberculosis are accessing second-line antituberculosis drugs; these are more toxic than first-line drugs. Little is known about the safety of new antituberculosis drugs in children. Knowledge of adverse effects, and how to assess and manage these, is important to ensure good adherence and treatment outcomes.

AREAS COVERED

A Pubmed search was performed to identify articles addressing adverse effects of second-line antituberculosis drugs; a general search was done for the new drugs delamanid and bedaquiline. This review discusses adverse effects associated with oral second-line antituberculosis drugs. The spectrum of adverse effects caused by antituberculosis drugs is wide; the majority are mild or moderate, but these are important to manage as it could lead to non-adherence to treatment. Adverse effects may be more common in HIV-infected than in HIV-uninfected children.

EXPERT OPINION

Although children may experience fewer adverse effects from oral second-line antituberculosis drugs than adults, evidence from prospective studies of the incidence of adverse events in children is limited. Higher doses of second-line drugs, new antituberculosis drugs, and new drug regimens are being evaluated in children: these call for strict pharmacovigilance in children treated in the near future, as adverse effect profiles may change.

Baseline Predictors of Treatment Outcomes in Children With Multidrug-Resistant Tuberculosis: A Retrospective Cohort Study

BACKGROUND

Globally, >30 000 children fall sick with multidrug-resistant (MDR) tuberculosis every year. Without robust pediatric data, clinical management follows international guidelines that are based on studies in adults and expert opinion. We aimed to identify baseline predictors of death, treatment failure, and loss to follow-up among children with MDR tuberculosis disease treated with regimens tailored to their drug susceptibility test (DST) result or to the DST result of a source case.

METHODS

This retrospective cohort study included all children ≤15 years old with confirmed and probable MDR tuberculosis disease who began tailored regimens in Lima, Peru, between 2005 and 2009. Using logistic regression, we examined associations between baseline patient and treatment characteristics and (1) death or treatment failure and (2) loss to follow-up.

RESULTS

Two hundred eleven of 232 (90.9%) children had known treatment outcomes, of whom 163 (77.2%) achieved cure or probable cure, 29 (13.7%) were lost to follow-up, 10 (4.7%) experienced treatment failure, and 9 (4.3%) died. Independent baseline predictors of death or treatment failure were the presence of severe disease (adjusted odds ratio [aOR], 4.96; 95% confidence interval [CI], 1.61-15.26) and z score ≤-1 (aOR, 3.39; 95% CI, 1.20-9.54). We did not identify any independent predictors of loss to follow-up.

CONCLUSIONS

High cure rates can be achieved in children with MDR tuberculosis using tailored regimens containing second-line drugs. However, children faced significantly higher risk of death or treatment failure if they had severe disease or were underweight. These findings highlight the need for early interventions that can improve treatment outcomes for children with MDR tuberculosis.

Recent Developments and Future Opportunities in the Treatment of Tuberculosis in Children

Tuberculosis in children accounts for a significant proportion of the overall burden of disease, and yet for many years research into pediatric treatment has been neglected. Recently, there have been major developments in our understanding of pediatric tuberculosis, and a large number of studies are under way or planned. New drugs and regimens are being evaluated, and older drugs are being repurposed. Shorter regimens with potentially fewer side effects are being assessed for the treatment and prevention of both drug-susceptible and drug-resistant tuberculosis. It may be possible to tailor treatment so that children with less severe disease are given shorter regimens, and weekly dosing is under investigation for preventive therapy and for the continuation phase of treatment. The interaction with human immunodeficiency virus and the management of tuberculosis meningitis are also likely to be better understood. Exciting times lie ahead for pediatric tuberculosis, but much work remains to be done.

Compassionate use of new drugs in children and adolescents with multidrug-resistant and extensively drug-resistant tuberculosis: early experiences and challenges

The World Health Organization (WHO) estimated that 480 000 new multidrug-resistant (MDR) tuberculosis (TB) cases occurred globally in 2014, with 190 000 deaths. Limited data are available on the burden of MDR-TB in children. A recent systematic review estimated that 32 000 children acquire MDR-TB annually; of these, very few are correctly diagnosed and provided with appropriate treatment [1].

First experience and challenges of compassionate use of new anti-TB drugs to treat MDR- and XDR-TB in childrenhttp://ow.ly/SWXF300a0UX

Childhood tuberculosis: A roadmap towards zero deaths

'Every day, more than 200 children under the age of 15 die needlessly from tuberculosis (TB) - a disease that is preventable and curable. The World Health Organization estimates that as many as 1 in 10 TB cases globally (6-10% of all TB cases) are among this age group, but the number could be even higher because many children are simply undiagnosed.' Childhood TB is emerging from the shadows. This quote comes from the recently launched international roadmap towards zero TB deaths in children. We provide a brief update of new developments and remaining challenges related to childhood TB, with particular emphasis on the new roadmap.

Recommendations for treating children with drug-resistant tuberculosis

Tuberculosis (TB) is still one of the most difficult infectious diseases to treat, and the second most frequent cause of death due to infectious disease throughout the world. The number of cases of multidrug-resistant (MDR-TB) and extensively drug-resistant TB (XDR-TB), which are characterised by high mortality rates, is increasing. The therapeutic management of children with MDR- and XDR-TB is complicated by a lack of knowledge, and the fact that many potentially useful drugs are not registered for pediatric use and there are no formulations suitable for children in the first years of life. Furthermore, most of the available drugs are burdened by major adverse events that need to be taken into account, particularly in the case of prolonged therapy. This document describes the recommendations of a group of scientific societies on the therapeutic approach to pediatric MDR- and XDR-TB. On the basis of a systematic literature review and their personal clinical experience, the experts recommend that children with active TB caused by a drug-resistant strain of Mycobacterium tuberculosis should always be referred to a specialised centre because of the complexity of patient management, the paucity of pediatric data, and the high incidence of adverse events due to second-line anti-TB treatment.

Advances in Drug Discovery and Development for Pediatric Tuberculosis

Pediatric tuberculosis is an underappreciated global epidemic estimated to afflict around half a million children worldwide. This problem has historically been overlooked, due in part to their low social status and the difficulty in diagnosis of tuberculosis in children. Children are more susceptible to tuberculosis infection and disease progression, including rapid dissemination into extrapulmonary infection sites. Treatment of pediatric tuberculosis infections has been traditionally built around agents used to treat the adult disease, but the disease pathology, drug pharmacokinetics and the safety window in children differs from the adult disease. This produces additional concerns for drug discovery and development of new agents. This review examines: (i) the safety concerns for current front and second line agents used to treat complex drug resistant infections and how this knowledge can be used to identify, prioritize and dose agents that may be better tolerated in pediatric populations; and (ii) the chemistry and suitability of new drugs in the clinical development pipeline for tuberculosis for the treatment of pediatric infections indicating several new agents may offer significant improvements for the treatment of multi-drug resistant tuberculosis in children.

Safety and tolerability profile of second-line anti-tuberculosis medications

Tuberculosis (TB) remains a major public health problem, representing the second leading cause of death from infectious diseases globally, despite being nearly 100 % curable. Multidrug-resistant (MDR)-TB, a form of TB resistant to isoniazid and rifampicin (rifampin), two of the key first-line TB drugs, is becoming increasingly common. MDR-TB is treated with a combination of drugs that are less effective but more toxic than isoniazid and rifampicin. These drugs include fluoroquinolones, aminoglycosides, ethionamide, cycloserine, aminosalicyclic acid, linezolid and clofazimine among others. Minor adverse effects are quite common and they can be easily managed with symptomatic treatment. However, some adverse effects can be life-threatening, e.g. nephrotoxicity due to aminoglycosides, cardiotoxicity due to fluoroquinolones, gastrointestinal toxicity due to ethionamide or para-aminosalicylic acid, central nervous system toxicity due to cycloserine, etc. Baseline evaluation may help to identify patients who are at increased risk for adverse effects. Regular clinical and laboratory evaluation during treatment is very important to prevent adverse effects from becoming serious. Timely and intensive monitoring for, and management of adverse effects caused by, second-line drugs are essential components of drug-resistant TB control programmes; poor management of adverse effects increases the risk of non-adherence or irregular adherence to treatment, and may result in death or permanent morbidity. Treating physicians should have a thorough knowledge of the adverse effects associated with the use of second-line anti-TB drugs, and routinely monitor the occurrence of adverse drug reactions. In this review, we have compiled safety and tolerability information regarding second-line anti-TB drugs in both adults and children.

Extensively drug-resistant tuberculosis in a young child after travel to India

Extensively drug-resistant (XDR) tuberculosis is becoming increasingly prevalent worldwide, but little is known about XDR tuberculosis in young children. In this Grand Round we describe a 2-year-old child from the USA who developed pneumonia after a 3 month visit to India. Symptoms resolved with empirical first-line tuberculosis treatment; however, a XDR strain of Mycobacterium tuberculosis grew in culture. In the absence of clinical or microbiological markers, low-radiation exposure pulmonary CT imaging was used to monitor treatment response, and guide an individualised drug regimen. Management was complicated by delays in diagnosis, uncertainties about drug selection, and a scarcity of child-friendly formulations. Treatment has been successful so far, and the child is in remission. This report of XDR tuberculosis in a young child in the USA highlights the risks of acquiring drug-resistant tuberculosis overseas, and the unique challenges in management of tuberculosis in this susceptible population.

How to manage children who have come into contact with patients affected by tuberculosis

Childhood tuberculosis (TB) indicates a recent infection, particularly in children aged < 5 years, and therefore is considered a sentinel event insofar as it highlights the presence of an undiagnosed or untreated source case. The risk of acquiring TB is directly proportional to the number of bacilli to which a subject is exposed and the environment in which the contact occurred. This document contains the recommendations of a group of Italian scientific societies for managing a child exposed to a case of TB based on an analysis of the risk factors for acquiring latent tuberculous infection (LTBI) and developing the disease, and the particular aspects TB transmission during the first years of life. The guidance includes a detailed description of the methods used to identify the index case, the tests that the exposed child should receive and the possibilities of preventive chemoprophylaxis depending on the patient's age and immune status, the chemotherapy and monitoring methods indicated in the case of LTBI, the management of a child who has come into contact with a case of multidrug-resistant or extensively drug-resistant TB, and the use of molecular typing in the analysis of epidemics. The group of experts identified risk factors for tuberculous infection and disease in pediatric age as well as gave recommendation on management of contacts of cases of TB according to their age, risk factors and exposure to multidrug-resistant or extensively drug-resistant TB.

Towards early inclusion of children in tuberculosis drugs trials: a consensus statement

Children younger than 18 years account for a substantial proportion of patients with tuberculosis worldwide. Available treatments for paediatric drug-susceptible and drug-resistant tuberculosis, albeit generally effective, are hampered by high pill burden, long duration of treatment, coexistent toxic effects, and an overall scarcity of suitable child-friendly formulations. Several new drugs and regimens with promising activity against both drug-susceptible and drug-resistant strains have entered clinical development and are either in various phases of clinical investigation or have received marketing authorisation for adults; however, none have data on their use in children. This consensus statement, generated from an international panel of opinion leaders on childhood tuberculosis and incorporating reviews of published literature from January, 2004, to May, 2014, addressed four key questions: what drugs or regimens should be prioritised for clinical trials in children? Which populations of children are high priorities for study? When can phase 1 or 2 studies be initiated in children? What are the relevant elements of clinical trial design? The consensus panel found that children can be included in studies at the early phases of drug development and should be an integral part of the clinical development plan, rather than studied after regulatory approval in adults is obtained.

Map the gap: missing children with drug-resistant tuberculosis

BACKGROUND

The lack of published information about children with multidrug-resistant tuberculosis (MDR-TB) is an obstacle to efforts to advocate for better diagnostics and treatment.

OBJECTIVE

To describe the lack of recognition in the published literature of MDR-TB and extensively drug-resistant TB (XDR-TB) in children.

DESIGN

We conducted a systematic search of the literature published in countries that reported any MDR- or XDR-TB case by 2012 to identify MDR- or XDR-TB cases in adults and in children.

RESULTS

Of 184 countries and territories that reported any case of MDR-TB during 2005-2012, we identified adult MDR-TB cases in the published literature in 143 (78%) countries and pediatric MDR-TB cases in 78 (42%) countries. Of the 92 countries that reported any case of XDR-TB, we identified adult XDR-TB cases in the published literature in 55 (60%) countries and pediatric XDR-TB cases for 9 (10%) countries.

CONCLUSION

The absence of publications documenting child MDR- and XDR-TB cases in settings where MDR- and XDR-TB in adults have been reported indicates both exclusion of childhood disease from the public discourse on drug-resistant TB and likely underdetection of sick children. Our results highlight a large-scale lack of awareness about children with MDR- and XDR-TB.

Pharmacokinetics and safety of moxifloxacin in children with multidrug-resistant tuberculosis

BACKGROUND

Moxifloxacin is currently recommended at a dose of 7.5-10 mg/kg for children with multidrug-resistant (MDR) tuberculosis, but pharmacokinetic and long-term safety data of moxifloxacin in children with tuberculosis are lacking. An area under the curve (AUC) of 40-60 µg × h/mL following an oral moxifloxacin dose of 400 mg has been reported in adults.

METHODS

In a prospective pharmacokinetic and safety study, children 7-15 years of age routinely receiving moxifloxacin 10 mg/kg daily as part of multidrug treatment for MDR tuberculosis in Cape Town, South Africa, for at least 2 weeks, underwent intensive pharmacokinetic sampling (predose and 1, 2, 4, 8, and either 6 or 11 hours) and were followed for safety. Assays were performed using liquid chromatography-tandem mass spectrometry, and pharmacokinetic measures calculated using noncompartmental analysis.

RESULTS

Twenty-three children were included (median age, 11.1 years; interquartile range [IQR], 9.2-12.0 years); 6 of 23 (26.1%) were human immunodeficiency virus (HIV)-infected. The median maximum serum concentration (Cmax), area under the curve from 0-8 hours (AUC0-8), time until Cmax (Tmax), and half-life for moxifloxacin were 3.08 (IQR, 2.85-3.82) µg/mL, 17.24 (IQR, 14.47-21.99) µg × h/mL, 2.0 (IQR, 1.0-8.0) h, and 4.14 (IQR, 3.45-6.11), respectively. Three children, all HIV-infected, were underweight for age. AUC0-8 was reduced by 6.85 µg × h/mL (95% confidence interval, -11.15 to -2.56) in HIV-infected children. Tmax was shorter with crushed vs whole tablets (P = .047). Except in 1 child with hepatotoxicity, all adverse effects were mild and nonpersistent. Mean corrected QT interval was 403 (standard deviation, 30) ms, and no prolongation >450 ms occurred.

CONCLUSIONS

Children 7-15 years of age receiving moxifloxacin 10 mg/kg/day as part of MDR tuberculosis treatment have low serum concentrations compared with adults receiving 400 mg moxifloxacin daily. Higher moxifloxacin dosages may be required in children. Moxifloxacin was well tolerated in children treated for MDR tuberculosis.

Tuberculosis in children

Tuberculosis (TB) is a major, but often unrecognised, cause of disease and death in young children from countries with high TB incidence rates among adults. It is also relevant to paediatricians in low-incidence countries, such as Australia, because of increased international travel, immigration and refugee resettlement. This manuscript provides a brief overview of the global TB disease burden, the natural history of disease in children, and offers guidance on the prevention, diagnosis and treatment of TB in children.

Commentary: a targets framework: dismantling the invisibility trap for children with drug-resistant tuberculosis

Tuberculosis (TB) is an airborne infectious disease that is both preventable and curable, yet it kills more than a million people every year. Children are highly vulnerable, but often invisible casualties. Drug-resistant forms of TB are on the rise globally, and children are as vulnerable as adults but less likely to be counted as cases of drug-resistant disease if they become sick. Four factors make children with drug-resistant TB 'invisible': first, the nature of the disease in children; second, deficiencies in existing diagnostic tools; third, overreliance on these tools; and fourth, our collective failure to deploy one effective tool for finding and treating children - contact investigation. We describe a nascent science-advocacy network - the Sentinel Project on Pediatric Drug-Resistant Tuberculosis - whose goal is to end child deaths from this disease. Provisional annual targets, focused on children exposed at home to multidrug-resistant TB, to be updated every year, constitute a framework to focus attention and collective actions at the community, national, and global levels. The targets in two age groups, under 5 and 5-14 years old, tell us the number of: (i) children who require complete evaluation for TB disease and infection; (ii) children who require treatment for TB disease; and (iii) children who would benefit from preventive therapy.

Tuberculosis in children

Many clinicians regard tuberculosis as an adult pulmonary disease, but tuberculosis (TB) is a major cause of disease, both pulmonary and extrapulmonary, and death in young children from TB-endemic countries, especially in areas affected by poverty, social disruption, and human immunodeficiency virus (HIV) infection. This article reviews the disease burden and the natural history of disease in children with TB. It also provides guidance regarding the diagnosis, treatment, and prevention of TB in children.

Multidrug-resistant and extensively drug-resistant tuberculosis: a review of current concepts and future challenges

Multidrug-resistant and extensively drug-resistant tuberculosis are recent global health issues, which makes tuberculosis - after the success of short course treatment during the second half of the last century - a major health challenge. Globalisation, health inequalities, competing economic interests and political instability contribute substantially to the spread of drug-resistant strains, which are associated with high rates of morbidity and mortality. Issues such as increasing transmission of drug-resistant strains, poor diagnostic coverage and a lengthy, toxic treatment need to be overcome by innovative approaches to tuberculosis control, prevention, diagnostics and treatment. This review addresses recent developments and future concepts.

Management of patients with multidrug-resistant/extensively drug-resistant tuberculosis in Europe: a TBNET consensus statement

The emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) substantially challenges TB control, especially in the European Region of the World Health Organization, where the highest prevalence of MDR/XDR cases is reported. The current management of patients with MDR/XDR-TB is extremely complex for medical, social and public health systems. The treatment with currently available anti-TB therapies to achieve relapse-free cure is long and undermined by a high frequency of adverse drug events, suboptimal treatment adherence, high costs and low treatment success rates. Availability of optimal management for patients with MDR/XDR-TB is limited even in the European Region. In the absence of a preventive vaccine, more effective diagnostic tools and novel therapeutic interventions the control of MDR/XDR-TB will be extremely difficult. Despite recent scientific advances in MDR/XDR-TB care, decisions for the management of patients with MDR/XDR-TB and their contacts often rely on expert opinions, rather than on clinical evidence.

This document summarises the current knowledge on the prevention, diagnosis and treatment of adults and children with MDR/XDR-TB and their contacts, and provides expert consensus recommendations on questions where scientific evidence is still lacking.

TBNET consensus statement on the management of patients with MDR/XDR-TB has been released in theEur Respir Jhttp://ow.ly/uizRD

The spread of drug-resistant tuberculosis in children: an Italian case series

Drug-resistant paediatric tuberculosis (TB) is an overlooked global problem. In Italy, the epidemiology of TB has recently changed and data regarding drug-resistant forms in the paediatric setting is scanty. The aim of this case series was to report the cases of drug-resistant TB, diagnosed between June 2006 and July 2010 in four Italian tertiary centres for paediatric infectious diseases, in children and adolescents living in Italy. Twenty-two children were enrolled, of these 17 were resistant to one or more drugs and five had multidrug-resistant TB. All but one child were either foreign born or had at least one foreign parent. Twenty-one patients completed their treatment without clinical or radiological signs of activity at the end of treatment, and one patient was lost to follow up. The outcomes were good, with few adverse effects using second-line anti-TB drugs. Although this series is limited, it might already reflect the worrisome increase of drug-resistant TB, even in childhood.

Controversies in preventive therapy for children contacts of multidrug-resistant tuberculosis

BACKGROUND

Drug-resistant tuberculosis (DR-TB) is emerging as an increasing problem worldwide and no consensus has been reached about the management of children contacts of DR-TB cases.

OBJECTIVE

To evaluate the role of post-exposure chemoprophylaxis in paediatric DR-TB contacts, focusing on literature findings and recommendations from existing international guidelines.

METHODS

We conducted a literature search of the Cochrane Library, MEDLINE by PubMed and EMBASE from database inception through September 2012, using an appropriate search strategy.

RESULTS

Eighteen articles were included: four retrospective and two prospective population studies, eight international guidelines and four narrative reviews.

CONCLUSIONS

General agreement exists that preventive therapy could be beneficial in specific high-risk groups, including immunocompromised children and those aged < 5 years. However, no consensus exists on the use of preventive therapy in older or immunocompetent children and on which regimen should be preferred.

Drug-resistant tuberculosis: pediatric guidelines

The World Health Organization estimates that there are 650,000 prevalent cases of multidrug-resistant (MDR) tuberculosis (TB) globally, and since children (<15 years of age) constitute up to 20 % of the TB caseload in high-burden settings, the number of children with drug-resistant (DR) TB is likely to be substantial. Because bacterial burden at the site of disease is often low, diagnosis involves collection of multiple specimens and a laboratory capable of performing culture, although the Xpert MTB/RIF assay has improved sensitivity over smear examination. The basic principles of treatment for children are the same as those for adults with MDR-TB; however, the treatment regimen is often empiric and based on the drug susceptibility pattern of the source case, if available, or on past history of treatment. Additional challenges arise when MDR-TB is diagnosed and managed in the context of HIV coinfection. HIV-infected children are also treated with antiretroviral therapy medications, which have the potential to interact with second-line anti-TB drugs. Lack of pediatric formulations of second-line drugs and paucity of pharmacokinetic data make dosage challenging. However, when treated appropriately, children with DR TB have good outcomes.

Diagnosis, treatment and prevention of tuberculosis in children

In Australia, tuberculosis notification rates have plateaued at a low level and disease is highly concentrated in immigrant communities where children may be affected. Many clinicians regard tuberculosis as an adult disease, hence it is rarely considered in the differential diagnosis of sick children. This paper provides a brief overview of the natural history of the disease in children to demonstrate the importance of taking a careful tuberculosis exposure history. It also provides guidance regarding the diagnosis, treatment and prevention of tuberculosis in children. The management of paediatric cases is not difficult if important differences with adult disease are carefully considered; these differences are discussed in detail.