Adoption of revised dosage recommendations for childhood tuberculosis in countries with different childhood tuberculosis burdens

Treatment and outcome in children with tuberculous meningitis - a multi-centre Paediatric Tuberculosis Network European Trials Group study

INTRODUCTION

Currently, data on treatment, outcome, and prognostic factors in children with tuberculous meningitis (TBM) in Europe are limited. To date, most existing data on TBM originate from adult studies, or studies conducted in low-resource settings.

METHODS

Multicentre, retrospective study involving 27 paediatric healthcare institutions in nine European countries via an established paediatric TB research network, before and after the 2014 revision of WHO dosing recommendations.

RESULTS

Of 118 children, 39 (33.1%) had TBM grade 1, 68 (57.6%) grade 2 and 11 (9.3%) grade 3. Fifty-eight (49.1%) children received a standard four-drug treatment regimen; other commonly used drugs included streptomycin, prothionamide, and amikacin. Almost half of the patients (48.3%; 56/116) were admitted to intensive care unit, with a median stay of 10 (IQR 4.5-21.0) days. Of 104 children with complete outcome data, 9.6% (10/104) died, and only 47.1% (49/104) recovered fully. Main long-term sequelae included spasticity of one or more limbs and developmental delay both in 19.2% (20/104), and seizure disorder in 17.3% (18/104). Multivariate regression analyses identified microbiological confirmation of TBM, the need for neurosurgical intervention and mechanical ventilation as risk factors for unfavourable outcome.

DISCUSSION

There was considerable heterogeneity in the use of TB drugs in this cohort. Despite few children presenting with advanced disease and the study being conducted in a high-resource setting, morbidity and mortality were high. Several risk factors for poor outcome were identified, which may aid prognostic predictions in children with TBM in the future.

Pharmacokinetics of first-line drugs in children with tuberculosis using WHO-recommended weight band doses and formulations

Background

Dispersible pediatric fixed-dose combination (FDC) tablets delivering higher doses of first-line antituberculosis drugs in World Health Organization–recommended weight bands were introduced in 2015. We report the first pharmacokinetic data for these FDC tablets in Zambian and South African children in the treatment-shortening SHINE trial.

Methods

Children weighing 4.0–7.9, 8.0–11.9, 12.0–15.9, or 16.0–24.9 kg received 1, 2, 3, or 4 tablets daily, respectively (rifampicin/isoniazid/pyrazinamide [75/50/150 mg], with or without 100 mg ethambutol, or rifampicin/isoniazid [75/50 mg]). Children 25.0–36.9 kg received doses recommended for adults <37 kg (300, 150, 800, and 550 mg/d, respectively, for rifampicin, isoniazid, pyrazinamide, and ethambutol). Pharmacokinetics were evaluated after at least 2 weeks of treatment.

Results

In the 77 children evaluated, the median age (interquartile range) was 3.7 (1.4–6.6) years; 40 (52%) were male and 20 (26%) were human immunodeficiency virus positive. The median area under the concentration-time curve from 0 to 24 hours for rifampicin, isoniazid, pyrazinamide, and ethambutol was 32.5 (interquartile range, 20.1–45.1), 16.7 (9.2–25.9), 317 (263–399), and 9.5 (7.5–11.5) mg⋅h/L, respectively, and lower in children than in adults for rifampicin in the 4.0–7.9-, 8–11.9-, and ≥25-kg weight bands, isoniazid in the 4.0–7.9-kg and ≥25-kg weight bands, and ethambutol in all 5 weight bands. Pyrazinamide exposures were similar to those in adults.

Conclusions

Recommended weight band–based FDC doses result in lower drug exposures in children in lower weight bands and in those ≥25 kg (receiving adult doses). Further adjustments to current doses are needed to match current target exposures in adults. The use of ethambutol at the current World Health Organization–recommended doses requires further evaluation.

Declining Trends in Childhood TB Notifications and Profile of Notified Patients in the City of Harare, Zimbabwe, from 2009 to 2018

Globally, childhood tuberculosis (TB among those aged <15 years) is a neglected component of national TB programmes in high TB burden countries. Zimbabwe, a country in southern Africa, is a high burden country for TB, TB-HIV, and drug-resistant TB. In this study, we assessed trends in annual childhood TB notifications in Harare (the capital of Zimbabwe) from 2009 to 2018 and the demographic, clinical profiles, and treatment outcomes of childhood TB patients notified from 2015–2017 by reviewing the national TB programme records and reports. Overall, there was a decline in the total number of TB patients (all ages) from 5,943 in 2009 to 2,831 in 2018. However, the number of childhood TB patients had declined exponentially 6-fold from 583 patients (117 per 100,000 children) in 2009 to 107 patients (18 per 100,000 children) in 2018. Of the 615 childhood TB patients notified between 2015 and 2017, 556 (89%) patient records were available. There were 53% males, 61% were aged <5 years, 92% were new TB patients, 85% had pulmonary TB, and 89% were treated for-drug sensitive TB, 3% for drug-resistant TB, and 40% were HIV positive (of whom 59% were on ART). Although 58% had successful treatment outcomes, the treatment outcomes of 40% were unknown (not recorded or not evaluated), indicating severe gaps in TB care. The disproportionate decline in childhood TB notifications could be due to the reduction in the TB burden among HIV positive individuals from the scale up of antiretroviral therapy and isoniazid preventive therapy. However, the country is experiencing economic challenges which could also contribute to the disproportionate decline in childhood TB notification and gaps in quality of care. There is an urgent need to understand the reasons for the declining trends and the gaps in care.

Outcomes in children treated for tuberculosis with the new dispersible fixed-dose combinations in Port Moresby

Setting

The new child-friendly fixed dose combinations (FDCs) were introduced at Port Moresby General Hospital, Papua New Guinea, in 2016 for the first-line treatment of children (aged <15 years) with tuberculosis (TB) who weighed <25 kg.

Objective

To describe the characteristics and outcomes for children treated with the new FDCs, and to identify risk factors for unfavourable treatment outcomes.

Design

This was a retrospective cohort study of all children treated for TB with the FDCs from August 2016 to August 2017.

Results

Of 713 children included, 488 (68%) were diagnosed with pulmonary TB. Only 6 (0.8%) TB cases were bacteriologically confirmed and human immunodeficiency virus (HIV) status was known in 50%. Treatment outcomes were favourable in 425 (60%) children. Of 288 children with unfavourable outcomes, there were 242 (84%) with loss to follow-up (LTFU) and 25 (8.4%) were known to have died. Children who were severely underweight (weight-for-age Z score <-3) on presentation were at greater risk of LTFU compared to children of normal weight on multivariable analysis (aRR 1.3, 95%CI 1.0-1.6, P < 0.05).

Conclusion

Alternative models of care to decrease LTFU during treatment are needed, including integration with nutritional support. Improving diagnosis through microbiological confirmation of TB and HIV are major challenges to be addressed.

Shorter treatment for minimal tuberculosis (TB) in children (SHINE): a study protocol for a randomised controlled trial

BACKGROUND

Tuberculosis (TB) in children is frequently paucibacillary and non-severe forms of pulmonary TB are common. Evidence for tuberculosis treatment in children is largely extrapolated from adult studies. Trials in adults with smear-negative tuberculosis suggest that treatment can be effectively shortened from 6 to 4 months. New paediatric, fixed-dose combination anti-tuberculosis treatments have recently been introduced in many countries, making the implementation of World Health Organisation (WHO)-revised dosing recommendations feasible. The safety and efficacy of these higher drug doses has not been systematically assessed in large studies in children, and the pharmacokinetics across children representing the range of weights and ages should be confirmed.

METHODS/DESIGN

SHINE is a multicentre, open-label, parallel-group, non-inferiority, randomised controlled, two-arm trial comparing a 4-month vs the standard 6-month regimen using revised WHO paediatric anti-tuberculosis drug doses. We aim to recruit 1200 African and Indian children aged below 16 years with non-severe TB, with or without HIV infection. The primary efficacy and safety endpoints are TB disease-free survival 72 weeks post randomisation and grade 3 or 4 adverse events. Nested pharmacokinetic studies will evaluate anti-tuberculosis drug concentrations, providing model-based predictions for optimal dosing, and measure antiretroviral exposures in order to describe the drug-drug interactions in a subset of HIV-infected children. Socioeconomic analyses will evaluate the cost-effectiveness of the intervention and social science studies will further explore the acceptability and palatability of these new paediatric drug formulations.

DISCUSSION

Although recent trials of TB treatment-shortening in adults with sputum-positivity have not been successful, the question has never been addressed in children, who have mainly paucibacillary, non-severe smear-negative disease. SHINE should inform whether treatment-shortening of drug-susceptible TB in children, regardless of HIV status, is efficacious and safe. The trial will also fill existing gaps in knowledge on dosing and acceptability of new anti-tuberculosis formulations and commonly used HIV drugs in settings with a high burden of TB. A positive result from this trial could simplify and shorten treatment, improve adherence and be cost-saving for many children with TB. Recruitment to the SHINE trial begun in July 2016; results are expected in 2020.

TRIAL REGISTRATION

International Standard Randomised Controlled Trials Number: ISRCTN63579542 , 14 October 2014. Pan African Clinical Trials Registry Number: PACTR201505001141379 , 14 May 2015. Clinical Trial Registry-India, registration number: CTRI/2017/07/009119, 27 July 2017.

Economic impact of thermostable vaccines

BACKGROUND

While our previous work has shown that replacing existing vaccines with thermostable vaccines can relieve bottlenecks in vaccine supply chains and thus increase vaccine availability, the question remains whether this benefit would outweigh the additional cost of thermostable formulations.

METHODS

Using HERMES simulation models of the vaccine supply chains for the Republic of Benin, the state of Bihar (India), and Niger, we simulated replacing different existing vaccines with thermostable formulations and determined the resulting clinical and economic impact. Costs measured included the costs of vaccines, logistics, and disease outcomes averted.

RESULTS

Replacing a particular vaccine with a thermostable version yielded cost savings in many cases even when charging a price premium (two or three times the current vaccine price). For example, replacing the current pentavalent vaccine with a thermostable version without increasing the vaccine price saved from $366 to $10,945 per 100 members of the vaccine's target population. Doubling the vaccine price still resulted in cost savings that ranged from $300 to $10,706, and tripling the vaccine price resulted in cost savings from $234 to $10,468. As another example, a thermostable rotavirus vaccine (RV) at its current (year) price saved between $131 and $1065. Doubling and tripling the thermostable rotavirus price resulted in cost savings ranging from $102 to $936 and $73 to $808, respectively. Switching to thermostable formulations was highly cost-effective or cost-effective in most scenarios explored.

CONCLUSION

Medical cost and productivity savings could outweigh even significant price premiums charged for thermostable formulations of vaccines, providing support for their use.

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.

Understanding Market Size and Reporting Gaps for Paediatric TB in Indonesia, Nigeria and Pakistan: Supporting Improved Treatment of Childhood TB in the Advent of New Medicines

Objective of the Study

We sought to understand gaps in reporting childhood TB cases among public and private sector health facilities (dubbed “non-NTP” facilities) outside the network of national TB control programmes, and the resulting impact of under-reporting on estimates of paediatric disease burden and market demand for new medicines.

Methodology

Exploratory assessments were carried out in Indonesia, Nigeria and Pakistan, reaching a range of facility types in two selected areas of each country. Record reviews and interviews of healthcare providers were carried out to assess numbers of unreported paediatric TB cases, diagnostic pathways followed and treatment regimens prescribed.

Main Findings

A total of 985 unreported diagnosed paediatric TB cases were identified over a three month period in 2013 in Indonesia from 64 facilities, 463 in Pakistan from 35 facilities and 24 in Nigeria from 20 facilities. These represent an absolute additional annualised yield to 2013 notifications reported to WHO of 15% for Indonesia, 2% for Nigeria and 7% for Pakistan. Only 12% of all facilities provided age and sex-disaggregated data. Findings highlight the challenges of confirming childhood TB. Diagnosis patterns in Nigeria highlight a very low suspicion for childhood TB. Providers note the need for paediatric medicines aligned to WHO recommendations.

Conclusion: How Market Data Can Support Better Public Health Interventions

This study emphasises the impact of incomplete reporting on the estimation of disease burden and potential market size of paediatric TB medicines. Further studies on “hubs” (facilities treating large numbers of childhood TB cases) will improve our understanding of the epidemic, support introduction efforts for new treatments and better measure markets for new paediatric medicines.

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.

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.