Management of multidrug-resistant tuberculosis in children: a survival guide for paediatricians

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.

Multidrug-Resistant TB (MDR-TB) and Extensively Drug-Resistant TB (XDR-TB) Among Children: Where We Stand Now

Drug-resistant tuberculosis (DR-TB) has continued to be a global health cataclysm. It is an arduous condition to tackle but is curable with the proper choice of drug and adherence to the drug therapy. WHO has introduced newer drugs with all-oral shorter regimens, but the COVID-19 pandemic has disrupted the achievements and raised the severity. The COVID-19 controlling mechanism is based on social distancing, using face masks, personal protective equipment, medical glove, head shoe cover, face shield, goggles, hand hygiene, and many more. Around the globe, national and international health authorities impose lockdown and movement control orders to ensure social distancing and prevent transmission of COVID-19 infection. Therefore, WHO proposed a TB control program impaired during a pandemic. Children, the most vulnerable group, suffer more from the drug-resistant form and act as the storehouse of future fatal cases. It has dire effects on physical health and hampers their mental health and academic career. Treatment of drug-resistant cases has more success stories in children than adults, but enrollment for treatment has been persistently low in this age group. Despite that, drug-resistant childhood tuberculosis has been neglected, and proper surveillance has not yet been achieved. Insufficient reporting, lack of appropriate screening tools for children, less accessibility to the treatment facility, inadequate awareness, and reduced funding for TB have worsened the situation. All these have resulted in jeopardizing our dream to terminate this deadly condition. So, it is high time to focus on this issue to achieve our Sustainable Development Goals (SDGs), the goal of ending TB by 2030, as planned by WHO. This review explores childhood TB's current position and areas to improve. This review utilized electronic-based data searched through PubMed, Google Scholar, Google Search Engine, Science Direct, and Embase.

Risk Factors for Adverse Events in Household Contacts Prescribed Preventive Treatment for Drug-resistant Tuberculosis Exposure

BACKGROUND

Completion of tuberculosis (TB) preventive treatment is important to optimize efficacy; treatment-related adverse events (AEs) sometimes result in discontinuation. This study describes the occurrence of AEs and their risk factors during a 6-month, 2-drug, fluoroquinolone-based preventive treatment for household contacts of patients with drug-resistant TB in Karachi, Pakistan.

METHODS

The primary outcome was development of any clinical AE during preventive treatment. Adverse events were categorized using the AE grading tables of the National Institutes of Health. Time-to-event analysis with Kaplan-Meier curves and Cox proportional hazards models accounting for recurrence were used to analyze associated risk factors.

RESULTS

Of the 172 household contacts on preventive treatment, 36 (21%) developed 64 AEs during 813 months of treatment. The incidence of AEs over 6 months of treatment was 7.9 per 100 person-months; 16 per 100 person-months with a fluoroquinolone and ethionamide, and 4.4 per 100 person-months with a fluoroquinolone and ethambutol. There were 53 (83%) grade 1 and 11 grade 2 AEs, with no grade 3 or 4 AEs. In multivariable analysis, the risk of AEs was higher in contacts prescribed ethionamide as compared to ethambutol adjusting for age, sex, and body mass index (adjusted hazard ratio, 2.1 [95% confidence interval {CI}, 1.2-3.6]). Overall, there was no notable difference in treatment completion among the contacts who experienced an AE and those who did not (crude odds ratio, 1.1 [95% CI, .52-2.5]).

CONCLUSIONS

A fluoroquinolone-based preventive treatment regimen for drug-resistant TB exposure is well tolerated. Regimens with ethionamide are more likely to result in AEs.

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.

Update on trends in childhood tuberculosis

PURPOSE OF REVIEW

Although tuberculosis (TB) causes much morbidity and mortality in children, diagnosis and treatment remain challenging. Recently, children have gained increasing attention in research and clinical trials driving improved contact management, case identification and treatment of both drug-susceptible and drug-resistant TB. This review highlights some recent advances.

RECENT FINDINGS

The tuberculin skin test is the most widely used test to distinguish Mycobacterium tuberculosis (M. tuberculosis) infection from active TB, however, using M. tuberculosis-specific, antigenic stimulation of CD4 and CD8 cells appear more effective. The use of Xpert MTB/RIF to identify M. tuberculosis in clinical samples, together with novel sampling methods have in part, overcome the difficulty of sampling and increased case identification capacity. Advances in treating both drug-susceptible and drug-resistant childhood TB show promise in being more paediatric friendly and improving adherence. Dosing strategies for drug-sensitive TB have improved with dispersible fixed drug combinations now available. In the treatment and prevention of drug-resistant TB, however, research involving the use of newer and more effective drugs currently recommended for adults, are still ongoing in children.

SUMMARY

The World Health Organization aims to end the TB epidemic by 2035 whereas the United Nations' Sustainable Developmental Goals sets this ambitious target for 2030. Therefore, adequate funding and implementing effective national TB programs must be prioritized, particularly in high-burden, low-income settings.

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.

Treatment Outcomes of Children With HIV Infection and Drug-resistant TB in Three Provinces in South Africa, 2005-2008

OBJECTIVE

To describe outcomes of HIV-infected pediatric patients with drug-resistant tuberculosis (DR TB).

METHODS

Demographic, clinical and laboratory data from charts of pediatric patients treated for DR TB during 2005-2008 were collected retrospectively from 5 multi-DR TB hospitals in South Africa. Data were summarized, and Pearson χ test or Fisher exact test was used to assess differences in variables of interest by HIV status. A time-to-event analysis was conducted using days from start of treatment to death. Variables of interest were first assessed using the Kaplan-Meier method. Cox proportional hazard models were fit to estimate crude and adjusted hazard ratios.

RESULTS

Of 423 eligible participants, 398 (95%) had culture-confirmed DR TB and 238 (56%) were HIV infected. A total of 54% were underweight, 42% were male and median age was 10.7 years (interquartile range: 5.5-15.3). Of the 423 participants, 245 (58%) were successfully treated, 69 (16%) died, treatment failed in 3 (1%), 36 (9%) were lost to follow-up and 70 (17%) were still on treatment, transferred or had unknown outcomes. Time to death differed by HIV status (P = 0.008), sex (P < 0.001), year of tuberculosis diagnosis (P = 0.05) and weight status (P = 0.002). Over the 2-year risk period, the adjusted rate of death was 2-fold higher among participants with HIV compared with HIV-negative participants (adjusted hazard ratio = 2.28; 95% confidence interval: 1.11-4.68).

CONCLUSIONS

Male, underweight and HIV-infected children with DR TB were more likely to experience death when compared with other children with DR TB within this study population.

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.

Preventing the spread of multidrug-resistant tuberculosis and protecting contacts of infectious cases

Prevention of multidrug-resistant and extensively drug-resistant tuberculosis (MDR/XDR-TB) is a top priority for global TB control, given the need to limit epidemic spread and considering the high cost, toxicity and poor treatment outcomes with available therapies. We performed a systematic literature review to evaluate the evidence for strategies to reduce MDR/XDR-TB transmission and disease progression. Rapid detection and timely initiation of effective treatment is critical to rendering MDR/XDR-TB cases non-infectious. The scale-up of rapid molecular testing has transformed the capacity of high-incidence settings to identify and treat patients with MDR/XDR-TB. Optimized infection control measures in hospitals and clinics are critical to protect other patients and healthcare workers, whereas creative measures to reduce transmission within community hotspots require consideration. Targeted screening of high-risk communities may enhance early case-detection and limit the spread of MDR/XDR-TB. Among infected contacts, preventive therapy promises to reduce the risk of disease progression. This is supported by observational cohort studies, but randomized trials are urgently needed to confirm these observations and guide policy formulation. Substantial investment in MDR/XDR-TB prevention and care will be critical if the ambitious global goal of TB elimination is to be realized.

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.

Linezolid is Associated with Improved Early Outcomes of Childhood Tuberculous Meningitis

BACKGROUND

Linezolid serves as an important component for the treatment of drug-resistant tuberculosis although there is little published data about linezolid use in children, especially in childhood tuberculous meningitis (TBM).

METHODS

In this study, we retrospectively reviewed records of childhood TBM patients who started treatment between January 2012 and August 2014. A total of 86 childhood TBM patients younger than 15 years old were enrolled. Out of 86 children, 36 (41.9%) received the regimen containing linezolid.

RESULTS

Thirty-two (88.9%) of 36 linezolid-treated cases had favorable outcomes, and 35 (70.0%) cases were successfully treated in the control group. The frequency of favorable outcome of linezolid group was significantly higher than that of control group (P = 0.037). In addition, compared with cases with fever clearance time of <1 week, the control group had more cases with fever clearance time of 1-4 weeks (P = 0.010) and >4 weeks (P = 0.000) than linezolid group. Furthermore, there was no significant difference in the frequency of adverse events between the two regimens (P = 0.896). In addition, the patients with adverse events were more likely to have treatment failure, the P value of which was 0.008.

CONCLUSIONS

Our data demonstrate that linezolid improves early outcome of childhood TBM. The low frequency of linezolid-associated adverse effects highlights the promising prospects of its use for treatment of childhood TBM.

[Multidrug-resistant tuberculosis in children: about two cases]

La tuberculose multirésistante chez l'enfant est une forme grave de la tuberculose, présentant un problème majeur de santé surtout dans les pays en voie de développement. Nous présentons le cas de deux enfants suivis dans notre formation pour tuberculose multirésistante mis sous schéma thérapeutique de deuxième ligne.

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.

Shoulder tuberculosis in children: a report of two cases

We report 2 children who underwent multidrug antituberculous therapy with rifampicin, isoniazid, ethambutol, and pyrazinamide followed by dedicated physiotherapy for tuberculosis of the shoulder. Both patients regained a range of motion comparable with the contralateral side after 9 to 10 months.

Childhood abdominal tuberculosis: Disease patterns, diagnosis, and drug resistance

OBJECTIVE

Childhood abdominal tuberculosis may be difficult to diagnose with certainty. Drug resistance adds to the challenge. We present our experience in children with this condition.

METHODS

The case records of all children <18 years of age and diagnosed as abdominal tuberculosis from January 2000 to April 2012 were reviewed. The clinical details; investigative profile (imaging, ascitic fluid analysis, upper gastrointestinal (GI) endoscopy, colonoscopy, and laparotomy); histopathology; microbiology; and response to antitubercular therapy was noted.

RESULTS

Thirty-eight children (median age 11, range 4-16 years) were diagnosed. Multiple intraabdominal sites were involved in 12 (32 %), peritoneal alone in 9 (24 %); isolated intestinal and isolated lymph nodal in 6 (16 %) each. Three children had atypical presentations with gastric outlet obstruction, acute lower GI bleeding, and duodenal perforation, respectively. Overall, definitive bacteriological diagnosis was possible in 47 % (18/38). In others, diagnosis was supported by histopathology (19 %) or other supportive investigations (34 %) along with a response to treatment without relapse. Drug-resistant disease was diagnosed in three (8 %, two multidrug resistant, one extended drug resistant) all of whom presented with a similar clinical picture of large abdominal lymph node masses.

CONCLUSION

Abdominal tuberculosis is still a challenging diagnosis with microbiological confirmation possible only in half of the cases. Atypical presentations and emergence of drug resistance should be kept in mind while managing these patients.

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.

Why do child contacts of multidrug-resistant tuberculosis not come to the assessment clinic?

BACKGROUND

Local policy advises that children exposed to multidrug-resistant tuberculosis (MDR-TB) should be assessed in a specialist clinic. Many children, however, are not brought for assessment.

METHODS

Focus group discussion was used to design appropriate questionnaires. From 1 September 2011, the first 50 children referred to the specialist paediatric MDR-TB clinic, Cape Town, South Africa, and who attended their clinic appointment, were recruited. The first 50 children who were referred but who did not attend were concurrently identified, traced and recruited. Differences in group characteristics were compared.

RESULTS

The median age of the children was 35 months: 48 (48%) were boys, 4 (4%) were human immunodeficiency virus infected and 47 (47%) were of coloured ethnicity. Factors significantly associated with non-attendance at the MDR-TB clinic were: Coloured ethnicity (OR 2.82, 95%CI 1.21-6.59, P = 0.01), the mother being the source case (OR 3.78, 95%CI 1.29-11.1, P = 0.02), having a smoker resident in the house (OR 2.37, 95%CI 1.01-5.57, P = 0.04), the time (P = 0.002) and cost (P = 0.03) required to get to the specialist clinic, and fear of infection whilst waiting to be seen (OR 2.45, 95%CI 1.07-5.60, P = 0.03).

CONCLUSIONS

Reasons for non-attendance at paediatric MDR-TB clinic appointments are complex and are influenced by demographic, social, logistical and cultural factors.

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.

Assessing the impact of multidrug-resistant tuberculosis in children: an exploratory qualitative study

BACKGROUND

While the prevalence of multidrug-resistant (MDR) tuberculosis (TB) is high among children in the Western Cape of South Africa, the psychosocial implications of treatment for children with MDR-TB remain poorly understood. We sought to explore how MDR-TB and its treatment impact children on an individual, familial, and social level.

METHODS

Semi-structured interviews were conducted with 20 children and caregivers purposively sampled from a prospective clinical cohort of children. The sample was stratified by age at the start of treatment (children >10 years, and 5-10 years). Caregiver proxy interviews were conducted with younger children, supplemented with child interviews; older children were interviewed directly, supplemented with caregiver proxy interviews. Data were analysed using grounded theory.

RESULTS

Findings revealed pill volume and adverse effects produced significant physical, psychological and academic disturbances in children. Adverse effects related to the medication were important obstacles to treatment adherence. While there appear to be no long-lasting effects in younger children, a few older children showed evidence of persisting internalised stigma. Caregivers suffered important treatment-related financial and psychological costs. Community support, notably through the continued involvement of children in strong social networks, promoted resilience among children and their families.

CONCLUSIONS

We found that the current treatment regimen for childhood MDR-TB has significant psychological, academic, and financial impacts on children and their families. There is a need for psychosocial support of children and caregivers to mitigate the negative effects of community stigma, and to manage the stressors associated with chronic illness.

Management of latent tuberculosis infection in child contacts of multidrug-resistant tuberculosis

After exposure to a teacher with multidrug-resistant pulmonary tuberculosis, 31 children developed latent infection. Twenty-six were treated with levofloxacin and pyrazinamide. Twelve required a change in therapy secondary to adverse effects. The most common adverse effects included abdominal pain, arthralgias/myalgias and elevated transaminases. All children reported at least 1 adverse effect. Fifteen children completed treatment. All adverse effects were transient.

Moxifloxacin for the treatment of pulmonary tuberculosis in children: a single center experience

OBJECTIVE

To report our experience on the safety and tolerability of moxifloxacin for treating children affected by pulmonary TB.

STUDY DESIGN

Children receiving a moxifloxacin-containing anti-TB regimen were included in the study. Their medical records were revised at the end of follow-up.

METHODS

We describe nine children treated with moxifloxacin for pulmonary TB at Regina Margherita Children's Hospital (Turin, Italy) between 2007 and 2012. Moxifloxacin was administered orally at 10 mg/kg/day once daily (maximum dose = 400 mg/day) following World Health Organization indications. During treatment, patients were systematically assessed for the development of side effects.

RESULTS

Eight children were considered cured at the end of treatment; one child was lost to follow-up after 3 months of treatment. Two children had side effects during treatment: one developed arthritis of the ankle; the other had liver toxicity, whose relationship with moxifloxacin could not be ruled out. We did not observe any case of QT prolongation, central nervous system disorders, growth defects or gastrointestinal disturbances.

CONCLUSIONS

A moxifloxacin-containing regimen might be considered for the treatment of TB in children, especially for drug-resistant and extensive forms. However, vigilance for possible side effects is recommended, especially if other drugs are concomitantly used. Studies on wider populations are needed to better define the impact of long-term treatments with quinolones on children's growth and psychomotor development and to outline regulatory indications on moxifloxacin use in the pediatric setting.

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

Tuberculosis and HIV co-infection in children

HIV is the top and tuberculosis is the second leading cause of death from infectious disease worldwide, with an estimated 8.7 million incident cases of tuberculosis and 2.5 million new HIV infections annually. The World Health Organization estimates that HIV prevalence among children with tuberculosis, in countries with moderate to high prevalence, ranges from 10 to 60%. The mechanisms promoting susceptibility of people with HIV to tuberculosis disease are incompletely understood, being likely caused by multifactorial processes. Paediatric tuberculosis and HIV have overlapping clinical manifestations, which could lead to missed or late diagnosis. Although every effort should be made to obtain a microbiologically-confirmed diagnosis in children with tuberculosis, in reality this may only be achieved in a minority, reflecting their paucibacillary nature and the difficulties in obtain samples. Rapid polymerase chain reaction tests, such as Xpert MTB/RIF assay, are increasingly used in children. The use of less or non invasive methods of sample collection, such as naso-pharyngeal aspirates and stool samples for a polymerase chain reaction-based diagnostic test tests and mycobacterial cultures is promising technique in HIV negative and HIV positive children. Anti-tuberculosis treatment should be started immediately at diagnosis with a four drug regimen, irrespective of the disease severity. Moreover, tuberculosis disease in an HIV infected child is considered to be a clinical indication for initiation of antiretroviral treatment. The World Health Organization recommends starting antiretroviral treatment in children as soon as anti-tuberculosis treatment is tolerated and within 2- 8 weeks after initiating it. The treatment of choice depends on the child's age and availability of age-appropriate formulations, and potential drug interactions and resistance. Treatment of multidrug resistant tuberculosis in HIV-infected children follows same principles as for HIV uninfected children. There are conflicting results on effectiveness of isoniazid preventive therapy in reducing incidence of tuberculosis disease in children with HIV.

CONCLUSION

Data on HIV/TB co-infection in children are still lacking. There are on-going large clinical trials on the prevention and treatment of TB/HIV infection in children that hopefully will help to guide an evidence-based clinical practice in both resource-rich and resource-limited settings.HIV is the top and tuberculosis is the second leading cause of death from infectious disease worldwide, with an estimated 8.7 million incident cases of tuberculosis and 2.5 million new HIV infections annually. The World Health Organization estimates that HIV prevalence among children with tuberculosis, in countries with moderate to high prevalence, ranges from 10 to 60%. The mechanisms promoting susceptibility of people with HIV to tuberculosis disease are incompletely understood, being likely caused by multifactorial processes.

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.

Ion-pair chromatography for simultaneous analysis of ethionamide and pyrazinamide from their porous microparticles

Ethionamide (ETA) and pyrazinamide (PZA) are considered the drugs of choice for the treatment of multidrug-resistant tuberculosis. Current methods available in the literature for simultaneous determination of ETA and PZA have low sensitivity or involve column modifications with lipophilic cations. The aim of this study was to develop a simple and validated reversed-phase ion-pair HPLC method for simultaneous determination of ETA and PZA for the characterization of polymeric-based porous inhalable microparticles in in vitro and spiked human serum samples. Chromatographic separation was achieved on a Phenomenex C18 column (250 mm × 4.6 mm) using a Shimadzu LC 10 series HPLC. The mobile phase consisted of A: 0.01% trifluoroacetic acid in distilled water and B: ACN/MeOH at 1:1 v/v. Gradient elution was run at a flow rate of 1.5 mL/min and a fixed UV wavelength of 280 nm. The validation characteristics included accuracy, precision, linearity, analytical range, and specificity. Calibration curves at seven levels for ETA and PZA were linear in the analytical range of 0.1-3.0 μg/mL with correlation coefficient of r (2) > 0.999. Accuracy for both ETA and PZA ranged from 94 to 106% at all quality control (QC) standards. The method was precise with relative standard deviation less than 2% at all QC levels. Limits of quantitation for ETA and PZA were 50 and 70 ng/mL, respectively. There was no interference from either the polymeric matrix ions or the biological matrix in the analysis of ETA and PZA.

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.

Management of difficult multidrug-resistant tuberculosis and extensively drug-resistant tuberculosis: update 2012

Multidrug-resistant (MDR) tuberculosis (TB) denotes bacillary resistance to at least isoniazid and rifampicin. Extensively drug-resistant (XDR) TB is MDR-TB with additional bacillary resistance to any fluoroquinolone and at least one second-line injectable drugs. Rooted in inadequate TB treatment and compounded by a vicious circle of diagnostic delay and improper treatment, MDR-TB/XDR-TB has become a global epidemic that is fuelled by poverty, human immunodeficiency virus (HIV) and neglect of airborne infection control. The majority of MDR-TB cases in some settings with high prevalence of MDR-TB are due to transmission of drug-resistant bacillary strains to previously untreated patients. Global efforts in controlling MDR-TB/XDR-TB can no longer focus solely on high-risk patients. It is difficult and costly to treat MDR-TB/XDR-TB. Without timely implementation of preventive and management strategies, difficult MDR-TB/XDR-TB can cripple global TB control efforts. Preventive strategies include prompt diagnosis with adequate TB treatment using the directly observed therapy, short-course (DOTS) strategy and drug-resistance programmes, airborne infection control, preventive treatment of TB/HIV, and optimal use of antiretroviral therapy. Management strategies for established cases of difficult MDR-TB/XDR-TB rely on harnessing existing drugs (notably newer generation fluoroquinolones, high-dose isoniazid, linezolid and pyrazinamide with in vitro activity) in the best combinations and dosing schedules, together with adjunctive surgery in carefully selected cases. Immunotherapy may also have a role in the future. New diagnostics, drugs and vaccines are required to meet the challenge, but science alone is insufficient. Difficult MDR-TB/XDR-TB cannot be tackled without achieving high cure rates with quality DOTS and beyond, and concurrently addressing poverty and HIV.

Peritoneal tuberculosis due to multidrug-resistant Mycobacterium tuberculosis

The emergence of drug-resistant Mycobacterium tuberculosis has been widely reported throughout the world, but there are very few data regarding children. We describe the case of a 14-year-old Peruvian adolescent who had been living in Italy since the age of 8 years and was diagnosed as having peritoneal tuberculosis (TB). While she was receiving first-line anti-TB therapy, she developed pyrazinamide-associated thrombocytopenia and cultures revealed a multidrug-resistant strain of Mycobacterium tuberculosis. Pyrazinamide, rifampicin and isoniazid were replaced by moxifloxacin, which was continued for 9 months together with ethambutol. The patient recovered without experiencing any drug-related adverse event or the recurrence of TB in the following year. In conclusion, this case illustrates some of the problems that can arise when multidrug-resistant TB has to be treated in children and adolescents, and also highlights the fact that further studies are needed to clarify which drugs should be used and for how long.

Drug-resistant tuberculosis in two children in Greece: report of the first extensively drug-resistant case

Extensively drug-resistant (XDR) tuberculosis (TB) represents a serious and growing problem in both endemic and non-endemic countries. We describe a 2.5-year-old girl with XDR-pulmonary TB and an 18-month-old boy with pre-XDR-central nervous system TB. Patients received individualized treatment with second-line anti-TB agents based on genotypic and phenotypic drug susceptibility testing results. Both children achieved culture conversion 3 months and 1 month after treatment initiation, respectively. The child with XDR-pulmonary TB showed evidence of cure while treatment adverse events were managed without treatment interruption. The child with pre-XDR-central nervous system TB after 6-month hospitalization with multiple infectious complications had a dismal end due to hepatic insufficiency possibly related to anti-TB treatment. This is the first report of children with pre-XDR and XDR TB in Greece, emphasizing the public health dimensions and management complexity of XDR TB.

Isoniazid- and streptomycin-resistant miliary tuberculosis complicated by intracranial tuberculoma in a Japanese infant

In Japan, the incidence of severe pediatric tuberculosis (TB) has decreased dramatically in recent years. However, children in Japan can still have considerable opportunities to contract TB infection from adult TB patients living nearby, and infants infected with TB may develop severe disseminated disease. A 3-month-old girl was admitted to our hospital with dyspnea and poor feeding. After admission, miliary TB and multiple brain tuberculomas were diagnosed. Anti-tuberculous therapy was initiated with streptomycin (SM), isoniazid (INH), rifampicin and pyrazinamide. Symptoms persisted after starting the initial treatment and mycobacterial cultures of gastric fluid remained positive. Drug sensitivity testing revealed the TB strain isolated on admission as completely resistant to INH and SM. Treatments with INH and SM were therefore stopped, and treatment with ethambutol and ethionamide was started in addition to rifampicin and pyrazinamide. After this change to the treatment regimen, symptoms and laboratory data gradually improved. The patient was treated with these four drugs for 18 months, and then pyrazinamide was stopped. After another 2 months, ethambutol was stopped. Treatment of tuberculosis was completed in 24 months. No adverse effects of these anti-TB drugs were observed. The patient achieved a full recovery without any sequelae. On the other hand, the infectious source for this patient remained unidentified, despite the extensive contact investigations. The incidence of drug-resistant TB is increasing in many areas of the world. Continuous monitoring for pediatric patients with drug-resistant TB is therefore needed.

Paediatric Multidrug-Resistant Tuberculosis with HIV Coinfection: A Case Report

Background. Tuberculosis is a major public health problem, and its control has been facing a lot of challenges with emergence of HIV. The occurrence of multidrug-resistant strain has also propounded the problem especially in children where diagnosis is difficult to make. Multidrug-resistant tuberculosis (MDR-TB) is in vitro resistant to isoniazid (H) and rifampicin (R). Paediatric multi-drug resistant tuberculosis with HIV coinfection is rare, and there is no documented report from Nigeria. Objective. To report a case of paediatric MDR-TB in Nigeria about it. Methods. The case note of the patient was retrieved, and relevant data were extracted and summarized. Results. A 9-year-old female HIV-positive pupil with a year history of recurrent cough, 3 months history of recurrent fever, and generalized weight loss was diagnosed and treated for tuberculosis but failed after retreatment. She was later diagnosed with MDR-TB and is presently on DOT-Plus regimen. Conclusion. Paediatric MDR-TB with HIV co-infection is rare. Early diagnosis and treatment is important to prevent spread of the disease. The use of Isoniazid preventive therapy is recommended for children who come in contact with patients with active tuberculosis and also for HIV patients without active tuberculosis.

Multidrug-resistant tuberculosis in children: evidence from global surveillance

Multidrug-resistant tuberculosis (MDR-TB) can affect persons of any age, but it remains unknown whether children are more or less likely than adults to have MDR-TB.

Representative drug resistance surveillance data reported to the World Health Organization between 1994 and 2011 were analysed to test the association between MDR-TB and age group (children aged <15 years versus adults aged ≥15 years), using odds ratios derived by logistic regression with robust standard errors.

Of 85 countries with data from nationwide surveys or surveillance systems, 35 reported at least one paediatric MDR-TB case. Aggregated data on age and drug susceptibility testing for 323 046 tuberculosis cases notified in these 35 countries were analysed. Odds ratios for MDR-TB in children compared to adults varied widely between countries. In Germany, Namibia, South Africa, the UK and the USA, MDR-TB was positively associated with age <15 years. In the remaining countries no association was established.

Despite the limitations intrinsic to the use of surveillance data and to the challenges of diagnosing childhood tuberculosis, our analysis suggests that proportions of MDR-TB in children and adults are similar in many settings. Of particular concern is the association found between age <15 years and MDR-TB in southern African countries with high HIV prevalence.

Surveillance data from 35 countries suggest that proportions of MDR-TB in children are not lower than those in adultshttp://ow.ly/kPgPH

Preventive therapy in children exposed to Mycobacterium tuberculosis: problems and solutions

Young children living with a tuberculosis patient are at high risk of Mycobacterium tuberculosis infection and disease. WHO guidelines promote active screening and isoniazid (INH) preventive therapy (PT) for such children under 5 years, yet this well-established intervention is seldom used in endemic countries. We review the literature regarding barriers to implementation of PT and find that they are multifactorial, including difficulties in screening, poor adherence, fear of increasing INH resistance and poor acceptability among primary caregivers and healthcare workers. These barriers are largely resolvable, and proposed solutions such as the adoption of symptom-based screening and shorter drug regimens are discussed. Integrated multicomponent and site-specific solutions need to be developed and evaluated within a public health framework to overcome the policy-practice gap and provide functional PT programmes for children in endemic settings.

Impact of drug resistance on clinical outcome in children with tuberculous meningitis

BACKGROUND

Tuberculous meningitis (TBM) is associated with delayed diagnosis and poor outcome in children. This study investigated the impact of drug resistance on clinical outcome in children with TBM.

METHODS

All children (0-13 years) were included if admitted to Tygerberg Children's Hospital, Cape Town, South Africa, from January 2003 to April 2009 with a diagnosis of either confirmed TBM, or probable TBM with mycobacterial isolation from a site other than cerebrospinal fluid. Mycobacterial samples underwent drug susceptibility testing to rifampin and isoniazid. Children were treated with isoniazid, rifampin, pyrazinamide and ethionamide according to local guidelines.

RESULTS

One hundred twenty-three children were included; 13% (16 of 123) had any form of drug resistance, and 4% (5 of 123) had multidrug-resistant tuberculosis. Time from start of symptoms to appropriate treatment was longer in children with any drug resistance (median: 31 days versus 9 days; P=0.001). In multivariable analysis, young age (P=0.013) and multidrug-resistant tuberculosis (adjusted odds ratio: 12.4 [95% confidence interval: 1.17-132.3]; P=0.037) remained risk factors for unfavorable outcome, and multidrug-resistant tuberculosis remained a risk for death (adjusted odds ratio: 63.9 [95% confidence interval: 4.84-843.2]; P=0.002). We did not detect any difference in outcome between those with isolates resistant to only isoniazid and those with fully susceptible strains (adjusted odds ratio: 0.22 [confidence interval: 0.03-1.87]; P=0.17).

CONCLUSION

Multidrug-resistant TBM in children has poor clinical outcome and is associated with death. We did not find any difference in the outcomes between children with isoniazid monoresistant TBM and those with drug-susceptible TBM. One explanation could be the local treatment regimen. Further investigation of this regimen is indicated.

Outcomes of comprehensive care for children empirically treated for multidrug-resistant tuberculosis in a setting of high HIV prevalence

BACKGROUND

Few studies have examined outcomes for children treated for multidrug-resistant tuberculosis (MDR-TB), including those receiving concomitant treatment for MDR-TB and HIV co-infection. In Lesotho, where the adult HIV seroprevalence is estimated to be 24%, we sought to measure outcomes and adverse events in a cohort of children treated for MDR-TB using a community-based treatment delivery model.

METHODS

We reviewed retrospectively the clinical charts of children ≤15 years of age treated for culture-confirmed or suspected MDR-TB between July 2007 and January 2011.

RESULTS

Nineteen children, ages two to 15, received treatment. At baseline, 74% of patients were co-infected with HIV, 63% were malnourished, 84% had severe radiographic findings, and 21% had extrapulmonary disease. Five (26%) children had culture-confirmed MDR-TB, ten (53%) did not have culture results available, and four (21%) subsequently had results indicating drug-susceptible TB. All children with HIV co-infection who were not already on antiretroviral therapy (ART) were initiated on ART a median of two weeks after the start of the MDR-TB regimen. Among the 17 patients with final outcomes, 15 (88%) patients were cured or completed treatment, two (12%) patients died, and none defaulted or were lost to follow-up. The majority of patients (95%) experienced adverse events; only two required permanent discontinuation of the offending agent, and only one required suspension of MDR-TB treatment for more than one week.

CONCLUSIONS

Pediatric MDR-TB and MDR-TB/HIV co-infection can be successfully treated using a combination of social support, close monitoring by community health workers and clinicians, and inpatient care when needed. In this cohort, adverse events were well tolerated and treatment outcomes were comparable to those reported in children with drug-susceptible TB and no HIV infection.

Diagnosis and management of TB in children: an update

In recent years, several notable modifications have occurred in the management of TB infection and disease in children. First, we review new data related to infection, including alternative regimens for the treatment of latent TB, management of drug-resistant infection and preventive therapy in the context of HIV infection. Next, we summarize updated WHO guidelines for the treatment of TB in children, explore issues specific to the management of disease in HIV-infected children, and retreatment of TB, and review pediatric recommendations for the management of drug-resistant TB. Finally, we conclude with a discussion of adjunctive therapy and new drugs in development.

Drug-resistant tuberculosis--current dilemmas, unanswered questions, challenges, and priority needs

Tuberculosis was declared a global emergency by the World Health Organization (WHO) in 1993. Following the declaration and the promotion in 1995 of directly observed treatment short course (DOTS), a cost-effective strategy to contain the tuberculosis epidemic, nearly 7 million lives have been saved compared with the pre-DOTS era, high cure rates have been achieved in most countries worldwide, and the global incidence of tuberculosis has been in a slow decline since the early 2000s. However, the emergence and spread of multidrug-resistant (MDR) tuberculosis, extensively drug-resistant (XDR) tuberculosis, and more recently, totally drug-resistant tuberculosis pose a threat to global tuberculosis control. Multidrug-resistant tuberculosis is a man-made problem. Laboratory facilities for drug susceptibility testing are inadequate in most tuberculosis-endemic countries, especially in Africa; thus diagnosis is missed, routine surveillance is not implemented, and the actual numbers of global drug-resistant tuberculosis cases have yet to be estimated. This exposes an ominous situation and reveals an urgent need for commitment by national programs to health system improvement because the response to MDR tuberculosis requires strong health services in general. Multidrug-resistant tuberculosis and XDR tuberculosis greatly complicate patient management within resource-poor national tuberculosis programs, reducing treatment efficacy and increasing the cost of treatment to the extent that it could bankrupt healthcare financing in tuberculosis-endemic areas. Why, despite nearly 20 years of WHO-promoted activity and >12 years of MDR tuberculosis-specific activity, has the country response to the drug-resistant tuberculosis epidemic been so ineffectual? The current dilemmas, unanswered questions, operational issues, challenges, and priority needs for global drug resistance screening and surveillance, improved treatment regimens, and management of outcomes and prevention of DR tuberculosis are discussed.

Pediatric drug-resistant tuberculosis: a global perspective: a global perspective

This article was based on a presentation given at the 26th International Pediatric Association Conference of Pediatrics, Johannesburg, South Africa, 4-9 August 2010. In 2009, there were 9.4 million new cases of tuberculosis (TB) globally, and, of these, approximately 1 million were pediatric cases. Drug-resistant TB makes up a relatively small proportion of new TB cases, but is much more likely in previously treated cases. Pediatric TB remains difficult to diagnose microbiologically, with the result that detection of drug-resistant TB in children is an ongoing challenge. Since children diagnosed with TB predominantly represent recently acquired TB infection, they provide an important indication of drug-resistant TB prevalence and transmission within their communities. Drug-resistant TB is essentially a man-made problem, which consumes large amounts of healthcare resources. Recent technologic advances may pave the way to more rapid and accurate diagnosis of TB in children. Similarly, these advances are likely to result in improved detection of drug-resistant pediatric TB isolates. The treatment of pediatric drug-resistant TB requires prolonged courses of expensive and potentially toxic drugs, many of which are not available in child-friendly formulations. New anti-TB drugs are at various stages of pre-clinical development and will hopefully allow for shorter, more effective treatment regimens in the not too distant future. HIV-infected children are at extremely high risk for TB acquisition and subsequent progression to symptomatic disease; therefore, many cases of pediatric drug-resistant TB occur in HIV-infected children. This often results in complicated pharmacologic regimens (including anti-TB and antiretroviral drugs) that are difficult to comply with and may have unpredictable interactions. There are limited reports of long-term clinical outcomes of children diagnosed with drug-resistant TB, but improvements in the diagnosis and pharmacologic management of these cases have the potential to improve the quality of care offered to these children.