Tuberculosis in children

Tuberculosis Preventative Therapy Initiation and Completion Among Adolescents and Young Adults Living With HIV in Kenya

BACKGROUND

Tuberculosis is the leading cause of death among adolescents and young adults living with HIV (YWHIV) and their heightened risk warrants deeper understanding of utilization of tuberculosis-prevention measures within HIV care.

SETTING

Retrospective study using clinic surveys and medical record data from 86 Kenyan HIV clinics.

METHODS

Clinic surveys obtained information on tuberculosis preventive therapy (TPT) services. Medical records of YWHIV were abstracted. Bivariate and multivariate analyses used generalized linear models to determine individual-level and clinic-level cofactors of TPT initiation and completion.

RESULTS

Among 10,328 eligible YWHIV, 4337 (42.0%) initiated TPT. Of 3295 with ≥6 months follow-up, 1774 (53.8%) completed TPT. A lower patient-to-staff ratio was a clinic-level cofactor of TPT initiation ( P = 0.044) and completion ( P = 0.004); designated adolescent areas were associated with TPT initiation {prevalence ratio 2.05 [95% confidence interval (CI): 1.46 to -2.88]}. Individual cofactors of TPT initiation included younger age at HIV-care enrollment [relative risk (RR) 0.85 (95% CI: 0.80 to 0.90)] and antiretroviral therapy (ART) duration [1-2 vs. <1 year RR 1.31 (95% CI: 1.18 to 1.45)]. TPT completion was associated with younger age [RR 0.91 (95% CI: 0.85 to 0.98)] and ART duration [2-5 vs. <1 year RR 1.27 (95% CI: 1.03 to 1.57)]. In multivariate models, TPT initiation was associated with younger age and ART duration [1-2 vs. 1 year; adjusted RR 1.30 (95% CI: 1.16 to 1.46)] and TPT completion with ART duration [2-5 vs. 1 year adjusted RR 1.23 (95% CI: 0.99 to 1.52)].

CONCLUSION

Over half of YWHIV did not initiate and >40% did not complete TPT, with distinct clinic-level and individual-level cofactors. Approaches to enhance adolescent-friendly infrastructure and support older YWHIV are necessary to improve TPT use.

Predominance of the Mycobacterium tuberculosis Beijing strain amongst children from a high tuberculosis burden township in South Africa

The objective was to determine the molecular epidemiology and drug susceptibility patterns of Mycobacterium tuberculosis (MTB) of children and their household contacts (HHC) in Umlazi, a high TB-burden township in South Africa. Sixty eight MTBRifPLUS positive TB-infected children (TIC) (≤14 years) and 111 HHC were enrolled. Drug susceptibility testing (DST) was performed on sputum samples using the proportion method and GenoType® MTBDR. Genotyping of MTB was conducted using IS6110-restriction fragment length polymorphism (RFLP) and spoligotyping. Rifampicin (RIF) susceptibility was observed in 67/68 TIC. GenoType® MTBDRplus and phenotypic DST identified drug resistant strains in five of 16 culture-confirmed TIC. The Beijing strain was identified in six and the F15/LAM4/KZN strain in one of the 13 TIC respectively. Four patients with unknown RFLP strains belonged to spoligoclades S, T1, T3 variant and X2. The S-lineage and an unknown strain were identified in two HHC. MDR-TB and pre-XDR-TB were identified in one HHC each. Household transmission could not be determined as none of the culture-confirmed TIC resided with the six culture-confirmed contacts. The predominance of the hypervirulent Beijing strain and presence of drug-resistant strains must be considered in the implementation of effective TB control strategies and development of efficacious vaccines.

Tuberculosis Transmission in a Primary School and a Private Language School. An Estimation of Infectivity

Introduction: Belgium is a country with low incidence of tuberculosis (TB) and a very low number of TB cases in children. Children in contact with an adult smear-positive TB case are at high risk of transmission. Early diagnosis is important as young children have a significant predisposition of developing TB disease. In this paper, we describe two outbreaks after exposure to, respectively, two teachers with smear-positive pulmonary TB: one in a primary school, a nursery teacher, and another in a private language school. Methods: An exposure investigation was carried out in both index cases household and school, according to the stone-in-the-pond principle. The tuberculin skin test (TST) was used a screening tool. The time elapsed between TB diagnosis in the index case and contact investigation was, respectively, 1 and 3 weeks. If this initial test was negative, it was repeated after a "window period" of ≥8 weeks. Results: Index cases showed a transmission rate of, respectively, 13 and 40% in their classes at school, defined as casual contacts. The proximity of contact increased the risk of infection. TB disease was observed in, respectively, 4 and 11% of all the casual contacts; all of them were children younger than 5 years old. TB-infected and children with active TB disease had good compliance with recommended treatment. Uptake of chemoprophylaxis during the "window period" was poor, respectively, only 32-42%, in children under 5 years with an initially negative TST. Discussion: The World Health Organization recommends to screen all young children (<5 years old) who have close contact with a person affected by pulmonary TB and to initiate Latent tuberculosis infection treatment even before infection can be demonstrated, after ruling out active TB disease. Despite this knowledge, a small percentage of the children younger than 5 years with no proof of infection was treated with the proposed chemoprophylactic treatment, in both cases. Conclusion: This exposure investigation of two teachers detects high transmission among family contacts and school casual contacts. Recommendations for chemoprophylactic treatment in children <5 years showed low compliance, reflecting the difficulty of communication to staff, parents, and children in a school outbreak. It is essential to develop a new approach for this vulnerable group of patients. This approach could be improved, applied, and evaluated by National TB Control Programs, involving public and private health services. Public health authorities play a role in raising public awareness about the risks of TB for young children.

The Role of HMGB1, a Nuclear Damage-Associated Molecular Pattern Molecule, in the Pathogenesis of Lung Diseases

Significance: High-mobility group protein box 1 (HMGB1), a ubiquitous nuclear protein, regulates chromatin structure and modulates the expression of many genes involved in the pathogenesis of lung cancer and many other lung diseases, including those that regulate cell cycle control, cell death, and DNA replication and repair. Extracellular HMGB1, whether passively released or actively secreted, is a danger signal that elicits proinflammatory responses, impairs macrophage phagocytosis and efferocytosis, and alters vascular remodeling. This can result in excessive pulmonary inflammation and compromised host defense against lung infections, causing a deleterious feedback cycle. Recent Advances: HMGB1 has been identified as a biomarker and mediator of the pathogenesis of numerous lung disorders. In addition, post-translational modifications of HMGB1, including acetylation, phosphorylation, and oxidation, have been postulated to affect its localization and physiological and pathophysiological effects, such as the initiation and progression of lung diseases. Critical Issues: The molecular mechanisms underlying how HMGB1 drives the pathogenesis of different lung diseases and novel therapeutic approaches targeting HMGB1 remain to be elucidated. Future Directions: Additional research is needed to identify the roles and functions of modified HMGB1 produced by different post-translational modifications and their significance in the pathogenesis of lung diseases. Such studies will provide information for novel approaches targeting HMGB1 as a treatment for lung diseases.

Inclusion of key populations in clinical trials of new antituberculosis treatments: Current barriers and recommendations for pregnant and lactating women, children, and HIV-infected persons

Amita Gupta and colleagues discuss priorities in clinical research aimed at improving tuberculosis prevention and treatment in pregnant women, children, and people with HIV.

Comparing tuberculosis in children aged under 5 versus 5 to 14 years old in a rural hospital in southern Ethiopia: an 18-year retrospective cross-sectional study

Background

There are few data available about childhood tuberculosis (TB) in rural hospitals in low-income countries. We assessed differences in epidemiological characteristics and treatment outcomes in children with TB aged 0–4 versus 5–14 years in rural Ethiopia.

Methods

For this retrospective cross-sectional study, we analyzed childhood TB registers from a rural Ethiopian hospital. We collected data on the number of cases, type of TB, and treatment outcomes using standard definitions. By means of binary and logistic regression analyses, data were compared from 1998 to 2015 in children aged under 5 versus those aged 5–14 years.

Results

We included 1282 TB patients: 583 (45.5%) were under 5 years old, and 699 (54.5%) were aged 5–14 years. More than half (67.2%, n = 862) had pulmonary TB (PTB), which was more common in younger children (82.5%, 481/583) than in older ones (54.5%, 381/699; p < 0.001). Most cases of PTB (87.5%, 754/862) were smear negative, including virtually all (99.6%, 479/481) younger children and most older ones (72.2%, n = 275/381; p < 0.001). The most common types of extrapulmonary TB (EPTB) were TB adenitis (54.5%, 229/420) and bone TB (20%, 84/420). Children under five showed a lower prevalence of adenitis TB (9.9% [58/583] versus 24.5% [171/699], p < 0.001), bone TB (2.9% [17/583] versus 9.6% [69/699], p < 0.001), and abdominal TB (0.9% [5/583] versus 6.3% [44/699], p < 0.001). Most diagnoses were new cases of TB (98.2%, 1259/1282). Overall, 63.5% (n = 814) of the children successfully completed treatment (< 5 years: 56.6%, 330/583; 5–14 years: 69.2%, 489/699; p < 0.001). In total, 16.3% (n = 209) transferred to another center (< 5 years: 19.4%, 113/583; 5–14 years: 13.7%, 96/699; p = 0.006). Thirteen percent of patients (n = 167) were lost to follow-up (< 5 years: 16.0%, 93/583; 5–14 years: 10.4%, 74/699; p = 0.004). Fifty-two (4.1%) children died (no age differences). Being aged 5–14 years was independently associated with successful treatment outcomes (adjusted odds ratio 1.59; 95% confidence interval: 1.16, 1.94, p = 0.002).

Conclusions

We observed a very low diagnostic yield for spontaneous sputum smear in children with TB. In this rural setting in Ethiopia, very young children tend to present with new cases of smear-negative PTB. They have less EPTB than older children but more TB meningitis and show lower rates of treatment success.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-7206-2) contains supplementary material, which is available to authorized users.

Latent tuberculosis may be missed by current screening practices: Analysis of interferon-gamma release assay results from a paediatric refugee clinic

AIMS

(i) To determine the prevalence of latent tuberculosis infection (LTBI) and characteristics associated with LTBI in children attending a paediatric refugee clinic and (ii) to determine whether current New South Wales (NSW) Health screening practices could miss LTBI cases.

METHODS

This was a retrospective analysis of tuberculosis (TB) screening data from refugee and asylum seeker children who attended a refugee clinic in a tertiary children's hospital during 2014 and 2015. We determined associations between LTBI and child characteristics at 5% significance levels.

RESULTS

Of 358 children attending the clinic, 235 children (66%) received interferon-gamma release assay (IGRA) testing, of whom 28 (11.9%) had positive results. Of the 28 with positive IGRAs, 12 (42.9%) would have been missed using NSW Health screening guidelines: two because they were younger than 2 years old, one who was born in Australia and 10 because they were not born in high TB incidence countries. IGRA results were not significantly associated with any of the child characteristics examined, including age, gender, travel through transit countries, boat versus plane arrival into Australia, whether the child had been in a detention centre or TB incidence in the source country.

CONCLUSIONS

We identified 12 children with LTBI who would have been missed using current NSW Health Department screening practices. These children are at risk of progression to active disease, particularly the two aged younger than 2 years old. We recommend universal screening.

Contribution of QuantiFERON-TB Gold-in-Tube to the Diagnosis of Mycobacterium tuberculosis Infection in Young Children in a Low TB Prevalence Country

Introduction: Interferon Gamma Release Assay (IGRA) has proven to be a useful test to evaluate the immune response to Mycobacterium tuberculosis antigens in children over the age of 5 years as an alternative to tuberculin skin testing (TST). Much less is known about its performance in younger children, who are at higher risk for developing tuberculosis (TB) disease after exposure. We aimed to evaluate the accuracy of using IGRA in TB screening in this population. Methods: Children below the age of 5 years at high risk for TB infection were prospectively enrolled, to compare the performance of TST and the QuantiFERON-TB Gold-In-Tube test (QFT). Children were treated in accordance with the diagnosis made at baseline and followed-up for 12 months. Results: We included a total of 60 children of which 97 blood samples were available for analysis. There was 90.72% agreement between TST and QFT (Kappa test 0.59, moderate agreement). With TST as a reference, the QFT positive predictive value was 0.72 and the negative predictive value 0.93. Discordant results were observed with 6% TST+/QFT- paired tests. When we restricted the comparison of TST and QFT to non-BCG-vaccinated children, the degree of agreement was more substantial (95%, Kappa test 0.75) and the negative predictive value was 0.99. We observed 3% discordant TST-/QFT+ results. All children with active TB disease had concordant positive QFT results, with QFT values above 4.00 IU/ml. Conclusion: In a low TB prevalence country, serial testing of QFT was found to produce a moderate agreement with TST results. False positive QFT results would have been eliminated by using a higher cutoff without misdiagnosing the children with TB disease. Some of the false negative QFT results could be explained by false positive TST results on consecutive testing. For now the most prudent approach would be to consider discordant QFT-/TST+ results as false negative QFT results, taking into account the young age of our population and the potential risk for evolution to active TB disease.

Operational implementation and impact of The Union's online childhood TB training course in South Africa

Novel, effective tuberculosis (TB) training strategies are needed in developing settings to scale up training and improve TB management at facility level. This study evaluated the feasibility of implementing an online childhood TB training course for community-based health-care workers in the Eastern Cape Province, South Africa, and measured its impact on knowledge. Training sessions were convened and participants completed the course independently. A total of 220 primary care participants completed pre- and post-training tests. The mean knowledge increase was 8% (95% confidence interval 7.0-8.8, P < 0.001). The course proved an acceptable, versatile option for decentralised training in childhood TB, provided that the technology requirements can be met.

Growth in HIV-infected children on long-term antiretroviral therapy

OBJECTIVES

To describe growth in HIV-infected children on long-term antiretroviral therapy (ART) and to assess social, clinical, immunological and virological factors associated with suboptimal growth.

METHODS

This observational cohort study included all HIV-infected children at an urban ART site in South Africa who were younger than 5 years at ART initiation and with more than 5 years of follow-up. Growth was assessed using weight-for-age Z-scores (WAZ), height-for-age Z-scores (HAZ) and body mass index (BMI)-for-age Z-scores (BAZ). Children were stratified according to pre-treatment anthropometry and age. Univariate and mixed linear analysis were used to determine associations between independent variables and weight and height outcomes.

RESULTS

The majority of the 159 children presented with advanced clinical disease (90%) and immunosuppression (89%). Before treatment underweight, stunting and wasting were common (WAZ<-2 = 50%, HAZ<-2 = 73%, BAZ<-2 = 19%). Weight and BMI improved during the initial 12 months, while height improved over the entire 5-year period. Height at study exit was significantly worse for children with growth impairment at ART initiation (P < 0.001), and infants (<1 year) demonstrated superior improvement in terms of BMI (P = 0.04). Tuberculosis was an independent risk factor for suboptimal weight (P = 0.01) and height (P = 0.02) improvement. Weight gain was also hindered by lack of electricity (P = 0.04). Immune reconstitution and virological suppression were not associated with being underweight or stunted at study endpoint.

CONCLUSIONS

Malnutrition was a major clinical concern for this cohort of HIV-infected children. Early ART initiation, tuberculosis co-infection management and nutritional interventions are crucial to ensure optimal growth in HIV-infected children.

Is Hyperuricemia Overlooked when Treating Pediatric Tuberculosis Patients with Pyrazinamide?

The treatment of tuberculosis (TB) requires long-term multiple drug use. Hyperuricemia is frequently reported in adults, but there are few data for the pediatric population. This study aimed to review drug-related side effects in pediatric patients that received treatment for TB. Patients with active TB undergoing treatment were followed for drug-related side effects. During the 7 year period, 23 patients with a mean age of 7.9 ± 4.66 years were treated. Drug-related side effects were observed in 14 patients. Hyperuricemia occurred in 12 of the 14 patients, vs. hepatotoxicity in 2. In all, eight of the patients with hyperuricemia had ≥2 episodes during pyrazinamide (PZA) therapy. Based on these findings, we devised an algorithm that could be used for the management of hyperuricemia in patients receiving PZA because of TB, and recommend that hyperuricemia be closely monitored during PZA therapy.