Global epidemiology of paediatric tuberculosis

Tuberculous Pericardial Effusions in Children

Current data on tuberculous pericardial effusion in children are limited. In this study, the cases of 30 children with tuberculous pericardial effusion were reviewed retrospectively. The prevalence of human immunodeficiency virus and of culture-confirmed tuberculosis was high. Chest radiography provided lower diagnostic sensitivity than sonography but detected all large and complicated effusions. Outcomes were generally good, and residual complications were mainly due to comorbidity.

The spectrum of tuberculosis of the spine in pediatric age group: a review

INTRODUCTION

Pediatric spinal tuberculosis is characterized by rapid bone destruction and carries the risk of rapid onset neurological deficits and severe deformity of the spine. Behavior of spinal deformity over time is affected by growth of spine. Owing to this dynamic behavior of pediatric spinal tuberculosis both in active phase and in healed phase, it presents with challenges which are quite different from adults with caries spine. A clinician must have high index of suspicion for accurate and early diagnosis of spinal tuberculosis in the pediatric population and should also have a thorough knowledge of differences in natural history between adult and pediatric spinal tuberculosis.

DISCUSSION

This is based on the senior author's experience of dealing with tuberculosis of the spine in children over the last two decades. Recent advances in field of rapid diagnosis of tuberculosis based on nuclear material-related diagnostic tests have further improved the management of tuberculosis. At the same time, the basic treatment principles remain the same. However, the threshold for surgical vs conservative treatment have subtle differences when compared to adult population. The importance of long-term follow-up after treatment must be appreciated.

CONCLUSION

Tuberculosis in the spine in children needs early attention. Prompting to diagnostic and medical therapy measures can avoid neurological sequellae and delayed deformity.

rs1800796 of the IL6 gene is associated with increased risk for anti-tuberculosis drug-induced hepatotoxicity in Chinese Han children

Previous studies have revealed the important contribution of the immune response and oxidative stress to the development of anti-tuberculosis drug-induced hepatotoxicity (ATDH). To investigate whether single-nucleotide polymorphisms (SNPs) of the cytokine gene interleukin-6 (IL6) and oxidative stress genes xanthine dehydrogenase/oxidase (XO) and inducible nitric oxide synthase (NOS2) were associated with susceptibility to ATDH, we performed a case-control study including 41 ATDH cases and 116 ATDH-free controls in Chinese Han children. Significant difference in the allele distribution of rs1800796 in the IL6 gene was observed between the case and control groups, and the G allele of rs1800796 was associated with an increased risk for ATDH (odds ratio: 2.48, 95%CI: 1.40-4.40, P = 0.002). However, no significant difference was observed in the allele and genotype distributions of the other SNPs of the IL6, XO and NOS2 genes between the case and control groups after Bonferroni correction. In addition, no interaction was found between all selected SNPs. These findings indicate that genetic variants of the IL6 gene might contribute to the development of ATDH in the Chinese Han pediatric population.

Mycobacterium bovis BCG and New Vaccines for the Prevention of Tuberculosis

Tuberculosis infects millions of people worldwide and remains a leading global killer despite widespread neonatal administration of the tuberculosis vaccine, bacillus Calmette-Guérin (BCG). BCG has clear and sustained efficacy, but after 10 years, its efficacy appears to wane, at least in some populations. Fortunately, there are many new tuberculosis vaccines in development today, some in advanced stages of clinical trial testing. Here we review the epidemiological need for tuberculosis vaccination, including evolving standards for administration to at risk individuals in developing countries. We also examine proven sources of immune protection from tuberculosis, which to date have exclusively involved natural or vaccine exposure to whole cell mycobacteria. After summarizing evidence for the use and efficacy of BCG, we detail the most promising new candidate vaccines against tuberculosis. The global need for a new tuberculosis vaccine is acute and huge, but clinical trials to be completed in the coming few years are likely either to identify a new tuberculosis vaccine or to substantially reframe how we understand immune protection from this historical scourge.

Isoniazid Preventive Therapy among Children Living with Tuberculosis Patients: Is It Working? A Mixed-Method Study from Bhopal, India

OBJECTIVE

We assessed uptake of isoniazid preventive therapy (IPT) among child contacts of smear-positive tuberculosis (TB) patients and its implementation challenges from healthcare providers' and parents' perspectives in Bhopal, India.

METHODS

A mixed-method study design: quantitative phase (review of programme records and house-to-house survey of smear-positive TB patients) followed by qualitative phase (interviews of healthcare providers and parents).

RESULTS

Of 59 child contacts (<6 years) of 129 index patients, 51 were contacted. Among them, 19 of 51 (37%) were screened for TB and one had TB. Only 11 of 50 (22%) children were started and 10 of 50 (20%) completed IPT. Content analysis of interviews revealed lack of awareness, risk perception among parents, cumbersome screening process, isoniazid stock-outs, inadequate knowledge among healthcare providers and poor programmatic monitoring as main barriers to IPT implementation.

CONCLUSION

National TB programme should counsel parents, train healthcare providers, simplify screening procedures, ensure regular drug supply and introduce an indicator to strengthen monitoring and uptake of IPT.

Diagnosis and treatment of paediatric tuberculosis: An insight review

Tuberculosis (TB) is a major public health problem, invading all age groups world-wide. It is an opportunistic infection affecting the individuals alone or with co-infections. Childhood TB is a neglected aspect and a significant health problem in epidemic areas. It constitutes more than 20% of TB incidence. Pediatric TB exists in the shadow of adult TB. The clinicians concentrate on pulmonary manifestation of TB, whereas it is a major problem in both pulmonary and extra-pulmonary infections. The rate of infection with this disease is mostly associated with poverty, social disruption and human immunodeficiency virus (HIV) infection. The diagnosis of extra-pulmonary TB (EPTB) is more difficult than pulmonary TB (PTB). Delayed diagnosis and executive treatment contribute to increase in the mortality rate in endemic areas. This article provides the evidence-based simple and safe screening method, indicating rapid, highly sensitive and specific diagnostic tests for pulmonary and EPTB in children. The most important aspect of treatment is the correct course of anti-tubercular drugs. This review serves the purpose of quick reference for microbiologists, epidemiologists, academicians, students and researchers. It provides guidance regarding early diagnosis and treatment accuracy of pediatric TB.

Prevalence of tuberculosis among children in North Sudan: Are we only seeing the tip of the iceberg?

INTRODUCTION

Tuberculosis (TB) is a significant cause of morbidity and mortality among children. The vague symptoms, the uncertain diagnostic tests and lack of adequate awareness among families all contributed in masking the actual prevalence of the disease. The objective of this study was to describe the epidemiology of childhood TB in River Nile State (RNS), North Sudan.

METHODS

All registered cases of TB aged 15 years and below, at the 13 management units in RNS during 3 years, 2011-2013 were included. The records included epidemiological, clinical, and microbiological data.

RESULTS

Out of the 1221 total TB notified cases, children were 187 (15.3%); almost equally distributed across the 3 years of the study period. Males were 56.7%. Most of the cases (89.9%) were newly diagnosed; among them, pulmonary TB (PTB) constituted 61.5%. Sputum specimen was tested in 59.4% (111/187) of cases, and only 15.3% (17/111) of specimens were sputum smear positive for new cases. The cure rate was (76.5%), and the treatment success rate was (88.2%). The death rate was 6.1% among PTB cases and 5.6% among extra-pulmonary cases. All the 20 (10.7%) children tested for HIV were negative.

CONCLUSION

TB is under-reported in RNS and treatment outcomes are sub-optimal. Strategies to identify the active case-detection among children are recommended.

The International Growth Standard for Children and Adolescents Project: Environmental Influences on Preadolescent and Adolescent Growth in Weight and Height

This review has two aims. The first is to identify important environmental influences on the growth of children aged 1 to 9 years and of adolescents, defined as those aged 10 to 19 years. The second is to identify possible environmentally based criteria for the selection of individuals and populations for data collection in the development of an international growth reference for these age ranges. There are many common environmental influences on the growth of children between the ages of 1 and 19 years; the examination and description of these forms the main body of this review. Subsequently, environmental factors influencing adolescent growth only are considered. In both cases, possible selection criteria are put forward. The most important inclusion criteria for both preadolescence and adolescence are good nutrition, lack of infection, and socioeconomic status that does not constrain growth. Additionally, low birthweight, catch-up growth, breastfeeding, and early adiposity rebound have impacts on growth and/or body composition into puberty. Exclusion of children born at low birth and/or experiencing catch-up growth could be most realistically operationalized if populations in which secular trends in growth were either completed or minimal were selected. Although an effect of hypoxia on child and adolescent growth, independent of nutrition, is small at most, many high-altitude populations have high prevalances of low birthweight and should be excluded on this basis. Since all populations are exposed to pollutants, contaminants, and toxicants in varying degrees, they cannot be realistically excluded from the sample frame. However, it may be desirable to exclude populations that are habitually exposed to extremely high levels of environmental pollution, including air pollution, and those living in close proximity to toxic waste. It is impossible to exclude populations and individuals on the basis of their exposure to aflatoxin contamination of food. However, exclusion on the basis of low socioeconomic status or poverty may well act as a proxy for this. There are a small number of populations that show extreme patterns of growth in body size and proportion in preadolescence and adolescence, and these should be excluded from the sample frame.

Rs1914663 of SFTPA 1 gene is associated with pediatric tuberculosis in Han Chinese population

Surfactant protein A (SP-A), a part of the innate immune system of the lung, performs a vital role in the host defense against Mycobacterium tuberculosis (MTB) infection. In order to investigate the relationship between SFTPA polymorphism variations and Tuberculosis (TB) in a Chinese pediatric group, we conducted a case-control study using single-nucleotide polymorphism (SNP) analysis. Significant difference of the allelic distribution of rs1914663 in SFTPA gene was observed between TB group and control group and, T allele of rs1914663 was associated with increased risk for TB (control vs.

TB, OR

1.42, 95% CI: 1.10-1.81, P=0.005). In addition, the TC+TT genotype of rs1914663 was higher in PTB and non-severe TB than that in controls. The haplotype comprising rs17881720-A and rs17879335-G was a resistance factor while the haplotype comprising rs1914663-T and rs1059225-G was found to be a susceptibility factor to TB. Using a case-control study, we identified a genetic polymorphism in the SFTPA that regulates host susceptibility to pediatric TB in the Han Chinese population.

Features of Adolescents Tuberculosis at a Referral TB's Hospital in Tehran, Iran

Objective

To identify the pattern of the clinical, radiological, diagnostic procedures and loss to follow-up of the diagnosed cases of active tuberculosis (TB) adolescents.

Methods

This study was a retrospective analysis of the medical records of 143 adolescents aged 10 to 18 years with tuberculosis who were admitted TB wards of National Research Institute of Tuberculosis and Lung Disease (NRITLD) in Tehran, Iran, between March 2006 and March 2011.

Results

Of the 143 patients identified, 62.9% were females. Median age of the patients was 16 years. The contact source was identified in 47.5%. The most common presenting symptom was cough (86%). Isolated pulmonary TB (PTB) was detected in 113 patients (79%), 21 patients (14.7%) had extrapulmonary TB(EPTB), and 9 patients (6.3%) had PTB and EPTB. The most common site of EPTB was pleural (14%). The most common radiographic finding was infiltration (61%). Positive acid fast smears were seen in 67.6%. Positive cultures for Mycobacterium tuberculosis (M. TB) were seen in 44.7%. Positive Polymerase chain reaction (PCR) results were seen in 60%. The adolescents aged 15 to 18 years were more likely to lose weight (p=0.001), smear positive (p=0.001), culture positive (p<0.001) and have positive PCR results (p=0.009). The type of TB (p=0.017) was a significant factor influencing loss to follow-up.

Conclusions

The study has revealed that the clinical and radiological findings of TB in adolescents are combination as identified in children and adults. The TB control programs should pay more attention to prevention and treatment of TB in adolescents.

[Scoliosis secondary to tuberculous spondylitis: A case report and discussion of diagnosis]

Idiopathic scoliosis is the most common form of spinal deformity in adolescence. However, secondary causes of scoliosis should always be considered so as to provide appropriate treatment and avoid complications. Additional explorations, such as MRI, are required in the presence of atypical signs. We report a case of spinal tuberculosis, or Pott's disease, misdiagnosed as idiopathic scoliosis, and then present a discussion to help identify the warning signs during the evaluation of scoliosis that might indicate secondary scoliosis and suggest when to perform further radiologic exploration.

Urban air pollution, poverty, violence and health--Neurological and immunological aspects as mediating factors

Rapid rural-urban migration has created overcrowded areas characterized by concentrated poverty and increases in indoor and outdoor air pollutants. These "hotspots" constitute an increased risk of violence and disease outbreaks. We hypothesize that the effects of poverty and associated air pollution-related stress on impaired cognitive skills are mediated by inflammatory cytokines. A research framework is proposed, encompassing (i) an epidemiological investigation of associations between poverty, high concentrations of air pollutants, violence and health, (ii) a longitudinal follow-up of working memory capacities and inflammatory markers, and (iii) intervention programs aiming to strengthen employability and decreased exposures to toxic air pollutants.

Differentiation between tuberculosis and leukemia in abdominal and pelvic lymph nodes: evaluation with contrast-enhanced multidetector computed tomography

PURPOSE

To compare the characteristics of tubercular vs. leukemic involvement of abdominopelvic lymph nodes using multidetector computed tomography (CT).

MATERIALS AND METHODS

We retrospectively reviewed multidetector computed tomography features including lymph node size, shape, enhancement patterns, and anatomical distribution, in 106 consecutive patients with newly diagnosed, untreated tuberculosis (55 patients; 52%) or leukemia (51 patients; 48%). In patients with leukemia, 32 (62.7%) had chronic lymphocytic leukemia, and 19 (37.3%) had acute leukemias; of these, 10 (19.6%) had acute myeloid leukemia, and 9 (17.6%) had acute lymphocytic leukemia.

RESULTS

The lower para-aortic (30.9% for tuberculosis, 63.2% for acute leukemias and 87.5% for chronic lymphocytic leukemia) and inguinal (9.1% for tuberculosis, 57.9% for acute leukemias and 53.1% for chronic lymphocytic leukemia) lymph nodes were involved more frequently in the three types of leukemia than in tuberculosis (both with p <0.017). Tuberculosis showed peripheral enhancement, frequently with a multilocular appearance, in 43 (78.2%) patients, whereas patients with leukemia (78.9% for acute myeloid leukemia and acute lymphocytic leukemia, 87.5% for chronic lymphocytic leukemia) demonstrated predominantly homogeneous enhancement (both with p <0.017). For the diagnosis of tuberculosis, the analysis showed that a peripheral enhancement pattern had a sensitivity of 78.2%, a specificity of 100%, and an accuracy of 88.7%. For the diagnosis of leukemia, the analysis showed that a homogeneous enhancement pattern was associated with a sensitivity of 84.3%, a specificity of 94.5%, and an accuracy of 89.6%.

CONCLUSION

Our findings indicate that the anatomical distribution and enhancement patterns of lymphadenopathy seen on multidetector computed tomography are useful for differentiating between untreated tuberculosis and leukemia of the abdominopelvic lymph nodes.

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.

Pulmonary tuberculous: Symptoms, diagnosis and treatment. 19-year experience in a third level pediatric hospital

Background

Pulmonary tuberculosis (PTB) is an infectious disease that involves the lungs and can be lethal in many cases. Tuberculosis (TB) in children represents 5 to 20% of the total TB cases. However, there are few updated information on pediatric TB, reason why the objective of the present study is to know the real situation of PTB in the population of children in terms of its diagnosis and treatment in a third level pediatric hospital.

Methods

A retrospective study based on a revision of clinical files of patients less than 18 years old diagnosed with PTB from January 1994 to January 2013 at Instituto Nacional de Pediatria, Mexico City was carried out. A probable diagnosis was based on 3 or more of the following: two or more weeks of cough, fever, tuberculin purified protein derivative (PPD) +, previous TB exposure, suggestive chest X-ray, and favorable response to treatment. Definitive diagnosis was based on positive acid-fast bacilli (AFB) or culture.

Results

In the 19-year period of revision, 87 children were diagnosed with PTB; 57 (65.5%) had bacteriologic confirmation with ZN staining or culture positive (in fact, 22 were ZN and culture positive), and 30 (34.5%) had a probable diagnosis; 14(16.1%) were diagnosed with concomitant disease, while 69/81 were immunized. Median evolution time was 21 days (5–150). Fever was found in 94.3%, cough in 77%, and weight loss in 55.2%. History of contact with TB was established in 41.9%. Chest X-ray showed consolidation in 48.3% and mediastinal lymph node in 47.1%. PPD was positive in 59.2%, while positive AFB was found in 51.7% cases. Culture was positive in 24/79 patients (30.4%), PCR in 20/27 (74.1%). 39 (44.8%) patients were treated with rifampin, isoniazid, and pyrazinamide while 6 (6.9%) received the former drugs plus streptomycin and 42 (48.3%) the former plus ethambutol. There were three deaths.

Conclusions

PTB in pediatric population represents a diagnostic challenge for the fact that clinical manifestations are unspecific and the diagnosis is not confirmed in all cases; that is why clinical suspicion, X-ray findings and PPD are indispensable for opportune start of treatment.

A 3'UTR polymorphism of IL-6R is associated with Chinese pediatric tuberculosis

Background. IL-6 is a proinflammatory cytokine that plays a critical role in host defense against tuberculosis (TB). Genetic polymorphisms of IL-6 and its receptor IL-6R had been discussed in adult TB recently. However, their role in pediatric TB is still unclear. Due to the obvious differences in TB pathophysiology in children, which may also reflect differences in genetic background, further association studies in pediatric populations are needed. Methods. A case-control study was carried out in a Chinese pediatric population including 353 TB patients and 400 healthy controls. Tag-SNPs of IL-6 and IL-6R genes were selected by Haploview software, genotyped using MassArray, and analyzed statistically. Results. One polymorphism, rs2229238, in the 3'UTR region of IL-6R was observed to be associated with increased resistance to TB (adjusted P = 0.03). The rs2229238 T allele contributed to a reduced risk to TB in recessive heritable model (OR, 0.53; 95% CI, 0.35–0.78). Conclusions. By tag-SNP genotyping based case-control study, we identified a genetic polymorphism in the IL-6R 3'UTR that regulates host resistance to pediatric TB in a Chinese population.

Tuberculosis epidemiology and selection in an autochthonous Siberian population from the 16th-19th century

Tuberculosis is one of most ancient diseases affecting human populations. Although numerous studies have tried to detect pathogenic DNA in ancient skeletons, the successful identification of ancient tuberculosis strains remains rare. Here, we describe a study of 140 ancient subjects inhumed in Yakutia (Eastern Siberia) during a tuberculosis outbreak, dating from the 16(th)-19(th) century. For a long time, Yakut populations had remained isolated from European populations, and it was not until the beginning of the 17(th) century that first contacts were made with European settlers. Subsequently, tuberculosis spread throughout Yakutia, and the evolution of tuberculosis frequencies can be tracked until the 19(th) century. This study took a multidisciplinary approach, examining historical and paleo-epidemiological data to understand the impact of tuberculosis on ancient Yakut population. In addition, molecular identification of the ancient tuberculosis strain was realized to elucidate the natural history and host-pathogen co-evolution of human tuberculosis that was present in this population. This was achieved by the molecular detection of the IS6110 sequence and SNP genotyping by the SNaPshot technique. Results demonstrated that the strain belongs to cluster PGG2-SCG-5, evocating a European origin. Our study suggests that the Yakut population may have been shaped by selection pressures, exerted by several illnesses, including tuberculosis, over several centuries. This confirms the validity and necessity of using a multidisciplinary approach to understand the natural history of Mycobacterium tuberculosis infection and disease.

rs2243268 and rs2243274 of Interleukin-4 (IL-4) gene are associated with reduced risk for extrapulmonary and severe tuberculosis in Chinese Han children

Interleukin-4 (IL-4) and IL-10, which are produced by Th2 cells, serve as anti-inflammatory cytokines in the immune responses to tuberculosis (TB). In order to investigate the association between susceptibility to TB and single-nucleotide polymorphisms (SNPs) of the IL-4 and IL-10 genes, a case-control study including 346 TB patients and 374 healthy controls was performed in Chinese Han children in North China. Though no significant differences in the allelic and genotypic distributions of SNPs of these two genes were observed between control group and TB group, rs2243268-A and rs2243274-G of the IL-4 gene were associated with reduced risk of developing extrapulmonary tuberculosis (EPTB) (Prs2243268=0.005 and Prs2243274=0.004) and severe TB (Prs2243268=0.003 and Prs2243274=0.003). The haplotype comprising rs2243268-A and rs2243274-G was found to be a resistance factor against EPTB and severe TB. In addition, after stimulation with inactivated H37Rv, blood samples of the rs2243268 AA+AC carriers showed significantly reduced IL-10 production (P=0.045) compared to the CC carriers. In conclusion, rs2243268-A and rs2243274-G of the IL-4 gene were found to confer resistance to EPTB and severe TB in Chinese Han children.

Intermittent versus daily therapy for treating tuberculosis in children

BACKGROUND

Childhood tuberculosis (TB) is a neglected global public health problem. Short treatment courses with rifampicin-containing anti-TB drugs given daily for six-months cure over 90% of infected children, but poor adherence reduces treatment success. Intermittent, short-course anti-TB regimens, given two or three times a week under direct observation, are associated with higher adherence in observational studies; but how they compare with daily treatment in relation to cure is unclear. Current international and national recommendations differ on use of intermittent regimens to treat TB in children.

OBJECTIVES

To compare the efficacy and safety of intermittent, short-course anti-TB regimens (twice- or thrice-weekly) with daily short-course anti-TB regimens in treating childhood TB.

SEARCH METHODS

We searched the Cochrane Infectious Disease Group Specialized Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, LILACS, clinical trials registries, regional databases, conference proceedings, and references without language restrictions up to 30 May 2013; and contacted experts for relevant published, unpublished, and on-going trials.

SELECTION CRITERIA

Randomized controlled trials (RCTs) and quasi-RCTs of children aged 15 years or younger, diagnosed with TB (according to the World Health Organization diagnostic categories 1, 2, or 3), who were treated with intermittent twice-weekly or thrice-weekly, short-course anti-TB regimens compared to daily short-course anti-TB treatment regimens. All regimens had to contain rifampicin for at least the first two months.

DATA COLLECTION AND ANALYSIS

The review authors independently screened and selected trials, assessed risk of bias, and extracted data. We sought clarifications from trial authors. We pooled relative risks with their 95% confidence intervals and used a random-effects model where there was significant heterogeneity. We assessed overall evidence-quality using the GRADE approach.

MAIN RESULTS

We included four trials published between 1996 to 2000 that randomized 563 children (465 evaluable) aged five months to 15 years to intermittent twice-weekly versus daily anti-TB treatment. Two trials were from India, one from South Africa, and one from Turkey. All trials used rifampicin and isoniazid, three trials used pyrazinamide, and one trial used streptomycin. The drug combination, and the duration of intermittent and daily treatments differed between trials, and no trials used drug combinations and schedules currently recommended for childhood TB. No trial reported if any child was HIV-positive.In comparisons of twice-weekly versus daily anti-TB treatment regimens, the trials did not detect differences in the number of patients cured, but trials were small, and the comparator regimens were not standard (four trials, 465 children; very low quality evidence). Trials were underpowered to provide estimates for death (two trials, 213 participants, very low quality evidence), relapse (one trial, 214 participants,very low quality evidence), and treatment limiting adverse events (four trials, 441 participants, very low quality evidence)Reported adherence to treatment was similar (87% versus 84%; four trials, 458 children, very low quality evidence)We did not find trials comparing the commonly used thrice-weekly anti-TB short-course regimen with the daily treatment regimen.

AUTHORS' CONCLUSIONS

Trials conducted to date are insufficient to support or refute the use of intermittent twice- or thrice-weekly, short-course treatment regimens over daily short-course treatment in children with TB. Further randomized trials conducted in high TB-transmission settings will help inform policy and practice.

Clinical peculiarities of tuberculosis

The ongoing spread of tuberculosis (TB) in poor resource countries and the recently increasing incidence in high resource countries lead to the need of updated knowledge for clinicians, particularly for pediatricians. The purpose of this article is to provide an overview on the most important peculiarities of TB in children. Children are less contagious than adults, but the risk of progression to active disease is higher in infants and children as compared to the subsequent ages. Diagnosis of TB in children is more difficult than in adults, because few signs are associated with primary infection, interferon-gamma release assays and tuberculin skin test are less reliable in younger children, M. tuberculosis is more rarely detected in gastric aspirates than in smears in adults and radiological findings are often not specific. Treatment of latent TB is always necessary in young children, whereas it is recommended in older children, as well as in adults, only in particular conditions. Antimycobacterial drugs are generally better tolerated in children as compared to adults, but off-label use of second-line antimycobacterial drugs is increasing, because of spreading of multidrug resistant TB worldwide. Given that TB is a disease which often involves more than one member in a family, a closer collaboration is needed between pediatricians and clinicians who take care of adults.

Pediatric vs adult pulmonary tuberculosis: A retrospective computed tomography study

AIM: To compare the manifestations of chest tuberculosis (TB) in pediatric and adult patients based on contrast enhanced computed tomography of chest.

METHODS: This was a retrospective study consisting of 152 patients of chest TB including 48 children and 104 adults who had undergone contrast enhanced computed tomography of chest prior to treatment. The patterns and severity of parenchymal, mediastinal and pleural manifestations were analyzed and compared among different age groups.

RESULTS: Parenchymal changes observed include consolidation, air space nodules, miliary TB, cavitation, bronchiectasis and fibrosis and these were noted in 60% of children, 71% of adolescents and 76.9% of adults. These changes were more common in right upper lobe in all age groups. There was no significant difference in the frequency of these changes (except nodules) in different age groups. Centrilobular nodules were seen less commonly in children less than 10 years (P = 0.028). Pleural effusion was noted in 28 (18.42%) patients and pericardial effusion in 8 (5.3%) patients. No significant difference in the serosal involvement is seen among children and adults. Mediastinal adenopathy was seen 70% of children, 76.3% adolescents and 76.9% of adults and paratracheal nodes were seen most frequently. Nodes had similar features (except matting) among all age groups. Matting of nodes was seen more commonly in children (P = 0.014).

CONCLUSION: Pediatric chest tuberculosis can have severe parenchymal lesions and nodal involvement similar to adults. The destructive lung changes observed in children needs immediate attention in view of the longer life span they have and hence in formulating optimal treatment strategies.

A functional promoter polymorphism of IFITM3 is associated with susceptibility to pediatric tuberculosis in Han Chinese population

A susceptibility locus for tuberculosis, a re-emerging infectious disease throughout the world, was previously discovered to exist on chromosome 11p15. IFITM3 gene encoding for interferon inducible transmembrane protein 3, is located at 11p15. It acts as an effector molecule for interferon-gamma, which is essential for anti-tuberculosis immune response. In order to investigate the association between susceptibility to TB and genetic polymorphisms of the IFITM3 core promoter, a case-control study including 368 TB patients and 794 healthy controls was performed in Han Chinese children in northern China. The rs3888188 polymorphism showed significant association with susceptibility to TB. The rs3888188 G allele, acting recessively, was more frequent in TB patients (95% confidence interval: 1.08–1.56, Bonferroni P-value: 0.039). We further assessed the effect of rs3888188 polymorphism on IFITM3 transcription in vitro. As based on luciferase promoter assays, the promoter activity of haplotypes with rs3888188 G allele was lower than that of haplotypes with rs3888188 T allele. Moreover, peripheral-blood mononuclear cells carrying rs3888188 GG genotype showed a reduced IFITM3 mRNA level compared to cells carrying TT or GT genotype. In conclusion, rs3888188, a functional promoter polymorphism of IFITM3, was identified to influence the risk for pediatric TB in Han Chinese population.

Circulating biomarkers of pulmonary and extrapulmonary tuberculosis in children

Tuberculosis (TB) in children is not only more likely to cause more severe disease than that seen in adults, it is also more likely to be extrapulmonary. Moreover, pediatric TB is very difficult to diagnose and suffers from a lack of understanding of host biomarkers for monitoring the progression of disease. Hence, we sought to identify the expression patterns of a variety of biomarkers in the plasma of children with pulmonary TB (PTB) and extrapulmonary TB (ETB), as well as in healthy control (HC) children. Thus, we examined a variety of circulating markers reflecting tissue inflammation, oxidative stress, innate immune activation, fibrosis, and the cytokine response. Children with active TB, compared to HC children, showed markedly elevated plasma levels of matrix metalloproteinases and their endogenous inhibitors. In addition, children with active TB had significantly elevated levels of C-reactive protein, α-2 macroglobulin, and haptoglobin, as well as hemoxygenase 1. Markers of innate immune activation (lipopolysaccharide [LPS] and lipopolysaccharide-binding protein [LBP]) were significantly lower in ETB than in PTB children. Although there were no significant differences between the two groups in their levels of cytokines (type 1 [gamma interferon (IFN-γ), tumor necrosis factor α (TNF-α), interleukin 2 (IL-2), and IL-12], type 2 [IL-4, IL-5, IL-13, and IL-33], and most type 17 [IL-17A, IL-22, IL-1β, and IL-6] and type 1 interferons [IFN-α and IFN-β]) or most of the cytokines associated with immune modulation (IL-10 and IL-20), pediatric TB was associated with elevated plasma transforming growth factor β (TGF-β), IL-21, and IL-23 levels. Thus, pediatric TB is characterized by elevated levels of a variety of biomarkers at homeostasis, suggesting that these responses may play a crucial role in disease pathogenesis.

Effectiveness of efavirenz-based regimens in young HIV-infected children treated for tuberculosis: a treatment option for resource-limited settings

BACKGROUND

Antiretroviral treatment (ART) options for young children co-infected with HIV and tuberculosis are limited in resource-poor settings due to limited data on the use of efavirenz (EFV). Using available pharmacokinetic data, an EFV dosing schedule was developed for young co-infected children and implemented as the standard of care at Macha Hospital in Southern Province, Zambia. Treatment outcomes in children younger than 3 years of age or weighing less than 10 kg receiving either EFV-based ART plus anti-tuberculous treatment or nevirapine-based (NVP) ART were compared.

METHODS

Treatment outcomes were measured in a cohort of HIV-infected children seeking care at Macha Hospital in rural Zambia from 2007 to 2010. Information on the diagnosis and treatment of tuberculosis was abstracted from medical records.

RESULTS

Forty-five children treated for tuberculosis initiated an EFV-based regimen and 69 children initiated a NVP-based regimen, 7 of whom also were treated for tuberculosis. Children receiving both regimens were comparable in age, but children receiving EFV started ART with a lower CD4(+) T-cell percentage and weight-for-age z-score. Children receiving EFV experienced increases in both CD4(+) T-cell percentage and weight-for-age z-score during follow-up, such that levels were comparable to children receiving NVP after two years of ART. Cumulative survival after 12 months of ART did not differ between groups (NVP:87%;EFV:80%;p = 0.25). Eleven children experienced virologic failure during follow-up.The adjusted hazard ratio of virologic failure comparing EFV to NVP was 0.25 (95% CI:0.05,1.24) and 0.13 (95% CI:0.03,0.62) using thresholds of 5000 and 400 copies/mL, respectively.Five children receiving EFV were reported to have had convulsions after ART initiation compared to only one child receiving NVP (p = 0.04).

CONCLUSIONS

Despite poorer health at ART initiation, children treated for tuberculosis and receiving EFV-based regimens showed significant improvements comparable to children receiving NVP-based regimens. EFV-based regimens should be considered for young HIV-infected children co-infected with tuberculosis in resource-limited settings.

A twenty-year retrospective study of pediatric tuberculosis in two tertiary hospitals in Rome

BACKGROUND

Tuberculosis (TB) is among the top 10 causes of child death worldwide. Nevertheless, childhood disease has been neglected by tuberculosis control programs.

METHODS

This was a retrospective study of patients < 16 years of age diagnosed with active TB in 2 tertiary hospitals in Rome (Italy), between 1990 and 2009.

RESULTS

Two hundred fourteen cases of active tuberculosis were identified (132 definite, 82 probable). Pulmonary involvement was the most common form (75.5%), followed by lymphadenopathy (15.4%) and central nervous system TB (11%). Fever (51.86%) and cough (40%) were the most common presenting symptoms. A total of 23.4% of children were asymptomatic on admission. Sensitivities of the tuberculin skin test and the quantiferon test were 93.4% and 97%, respectively. Both tests performed in 52 children agreed in 49 cases (94%). Sensitivities for culture, Ziehl-Neelsen staining and polymerase chain reaction were 58%, 25% and 66.3%, respectively. The adult source case was identified in 28% of cases. History of contact with a patient with active TB was associated with pulmonary TB (P = 0.0014), whereas negative history of contact was associated with lymph node (P = 0.0064) and central nervous system TB (P = 0.05).

CONCLUSIONS

Our study emphasizes the difficulty in managing children with suspected TB, because the absence of constitutional symptoms cannot exclude TB, and bacteriologic confirmation is the exception. Immunologic diagnosis can be a valuable tool to identify TB-infected children because the quantiferon test showed high sensitivity in all age groups. This is of primary importance because early identification of children with latent tuberculous infection and appropriate chemoprophylaxis represent, to date, the most important tool to reduce the burden of TB.

Multidrug-resistant tuberculosis of the spine in children--characteristics from a high burden setting

BACKGROUND

Few studies have described children with spinal multidrug-resistant tuberculosis (MDR-TB). Treatment involves surgery and medical care with long courses of drug therapy.

METHODS

Hospital and laboratory records at Brooklyn Chest and Tygerberg Children's Hospitals, Cape Town, South Africa, were analysed (January 2004 until December 2010) searching for children treated for MDR spinal TB.

RESULTS

Of the 11 children identified, 4 were excluded. Of the 7 remaining, 5 were boys; median age: 8 years, median delay to treatment initiation: 36 weeks. Among them one child died, five have completed treatment and one is near the end of therapy. Medications were well-tolerated and although two of the surviving children have spinal deformity, none have significant neurological deficit.

CONCLUSIONS

The diagnosis of spinal MDR-TB is often delayed in children, frequently leading to advanced disease and severe vertebral damage. Children tolerate therapy well and, once identified, it is a condition that can be treated successfully.

Evaluation of new strategies for the diagnosis of tuberculosis among pediatric contacts of tuberculosis patients

BACKGROUND

In young children, underdiagnosis and diagnostic delay have an adverse effect on morbidity and mortality of tuberculosis (TB). This study evaluated new strategies for early TB diagnosis using an outpatient protocol in children between 0 and 5 years of age, with a recent household TB contact.

METHODS

Case recruitment was performed in Manaus, Amazonas, Brazil, from 2008 to 2009. Epidemiologic and clinical data, tuberculin test, chest radiograph and 2 induced sputum respiratory samples from each participant were obtained. Laboratory diagnosis was based on Lowenstein-Jensen (LJ) culture, mycobacteria growth indicator tube (MGIT) and polymerase chain reaction. We conducted a study of comparison of diagnostic tests and a study of cases and controls to identify the clinical characteristics of the population with positive culture and polymerase chain reaction results.

RESULTS

A total of 102 children were evaluated. Thirty-two fulfilled criteria of suspicion of TB. MGIT was more sensitive (P = 0.035) and faster (P < 0.001) than LJ. Clinical score, MGIT, LJ and polymerase chain reaction presented no concordance or slight concordance. A positive MGIT culture was only associated with a strong tuberculin test reaction (P = 0.026). The combination of MGIT with the clinical score allowed the diagnosis of 33% more cases with little or no symptomatology compared with the exclusive use of the clinical classification.

CONCLUSIONS

The sensitivity and speed of MGIT demonstrate the utility of liquid cultures for the diagnosis in children. Furthermore, these results suggest that the use of MGIT in children presenting recent household TB contact and a strong tuberculin test reaction may be a strategy to improve early TB diagnosis.

Risk factors for in-hospital mortality among children with tuberculosis: the 25-year experience in Peru

OBJECTIVE

We examined factors associated with in-hospital death among children with tuberculosis (TB). We hypothesized that a negative response to tuberculin skin testing (TST) would predict decreased survival.

METHODS

This retrospective cohort comprised 2392 children ages 0 to 14 years hospitalized with TB at a Peruvian referral hospital over the 25-year study period. Detailed chart abstraction captured clinical history including TB contacts, physical examination findings, diagnostic data, treatment regimen, and hospitalization outcome. We used Cox proportional hazards regression analyses to determine risk factors for mortality.

RESULTS

Of 2392 children, 2 (0.1%) were known to be HIV-positive, 5 (0.2%) had documented multidrug-resistant TB, and 266 (11%) died. The median time from hospitalization to death was 16 days (interquartile range: 4-44 days). Reaction of <5 mm induration on TST predicted death in a multivariable analysis (hazard ratio [HR]: 3.01; 95% confidence interval [CI]: 2.15-4.21; P < .0001). Younger age, period of admission, alteration of mental status (HR: 3.25; 95% CI: 2.48-4.27; P < .0001), respiratory distress (HR: 1.40; 95% CI: 1.07-1.83; P = .01), peripheral edema (HR: 1.97; 95% CI: 1.42-2.73; P < .0001), and hemoptysis (HR: 0.57; 95% CI: 0.32-1.00; P = .05) were associated with mortality. Treatment regimens that contained rifampicin (HR: 0.47; 95% CI: 0.33-0.68; P < .0001) were associated with improved survival.

CONCLUSIONS

Negative reaction to TST is highly predictive of death among children with active TB. In children with clinical and radiographic findings suggestive of TB, a negative TST should not preclude or delay anti-TB therapy.

Childhood tuberculosis in household contacts of newly diagnosed TB patients

INTRODUCTION

Childhood tuberculosis (TB), although estimated to account for a major proportion of the global TB disease burden, has a lower public health priority. Reliable research and surveillance data on childhood TB is limited in most regions of the world. This study was conducted to assess the burden of childhood TB among the household contacts of new TB patients in Karachi, Pakistan.

METHODS

A retrospective analysis of children (<15 years) who were household contacts of new adult TB patients presenting to Marie Adelaide Leprosy Center (MALC) clinics in Karachi during the period of 2008 to 2010 was conducted.

RESULTS

Of the household children contacts (n = 6613) screened, 317 were suspected and 121(1.8%) diagnosed with TB. These included 89 (73.6%) with pulmonary and 32 (26.4%) with extra-pulmonary disease. Smear positivity rate in pulmonary cases was 32.6%. Mean age of children diagnosed with TB was 11.7 (± 2.8) years. Within the child-contacts screened, disease was found to be significantly higher among females (2.3%) in comparison to males (1.2%) (p-value <0.01). The commonest relationship of source cases to diagnosed children was the mother (n = 51, 42.1%). The source case was a female for 66.1% (n = 76) of the children.

CONCLUSION

A smear positivity rate of 32.6% amongst pulmonary cases suggests their potential to spread disease and emphasizes a need to review the contribution of children in transmission of TB within communities. Greater vulnerability of the female child and considerable role of mother in disease transmission highlights a need to increase focus on females in TB control programs in Pakistan.

Reduction in mycobacterial disease among HIV-infected children in the highly active antiretroviral therapy era (1997-2008)

BACKGROUND

HIV-infected children are at increased risk of developing mycobacterial disease. The aim of this study was to estimate the change in mycobacterial disease rate in HIV-infected children and adolescents in the highly active antiretroviral therapy (HAART) era.

METHODS

We carried out a retrospective study. Data were obtained from the records of the minimum basic data set of hospitals in Spain from 1997 to 2008. The epidemiologic trends of mycobacterial diseases were evaluated through the following 3 calendar periods: early-period HAART (1997-1999), midperiod HAART (2000-2002), and late-period HAART (2003-2008).

RESULTS

We analyzed 1307 HIV-infected children and 5228 HIV-uninfected children. HIV-infected children had similar rate of tuberculosis (TB) and nontuberculous mycobacteria (NTM) disease, and they had an overall rate of mycobacterial disease higher than that of HIV-uninfected children (P < 0.001). In HIV-infected children, the highest rates were for pulmonary TB (15/42 [35.7%]) in the TB category and disseminated mycobacterium (9/42 [21.4%]) in the NTM category. The overall rate of mycobacterial disease (events per 1000 HIV-infected children-year) decreased from 1997-1999 to 2003-2008 (5.88-1.63, P = 0.007) and from 2000-2002 to 2003-2008 (4.20-1.63, P = 0.021). Furthermore, the rate of TB decreased from 1997-1999 to 2000-2002 (3.53-0.84, P = 0.016) and from 1997-1999 to 2003-2008 (3.53-1.31, P = 0.030), and the rate of NTM disease decreased from 2000-2002 to 2003-2008 (3.36-0.32, P = 0.002).

CONCLUSIONS

The rate of mycobacterial disease decreased among HIV-infected children in the HAART era, but the incidence of mycobacterial disease still remains higher than in the general population.

Granulysin-expressing CD4+ T cells as candidate immune marker for tuberculosis during childhood and adolescence

Background

Granulysin produced by cytolytic T cells directly contributes to immune defense against tuberculosis (TB). We investigated granulysin as a candidate immune marker for childhood and adolescent TB.

Methods

Peripheral blood mononuclear cells (PBMC) from children and adolescents (1–17 years) with active TB, latent TB infection (LTBI), nontuberculous mycobacteria (NTM) infection and from uninfected controls were isolated and restimulated in a 7-day restimulation assay. Intracellular staining was then performed to analyze antigen-specific induction of activation markers and cytotoxic proteins, notably, granulysin in CD4⁺ CD45RO⁺ memory T cells.

Results

CD4⁺ CD45RO⁺ T cells co-expressing granulysin with specificity for Mycobacterium tuberculosis (Mtb) were present in high frequency in TB-experienced children and adolescents. Proliferating memory T cells (CFSE_lowCD4⁺CD45RO⁺) were identified as main source of granulysin and these cells expressed both central and effector memory phenotype. PBMC from study participants after TB drug therapy revealed that granulysin-expressing CD4⁺ T cells are long-lived, and express several activation and cytotoxicity markers with a proportion of cells being interferon-gamma-positive. In addition, granulysin-expressing T cell lines showed cytolytic activity against Mtb-infected target cells.

Conclusions

Our data suggest granulysin expression by CD4⁺ memory T cells as candidate immune marker for TB infection, notably, in childhood and adolescence.

Plasma antibody profiles as diagnostic biomarkers for tuberculosis

Two billion people are infected with Mycobacterium tuberculosis, the etiological agent of tuberculosis (TB), worldwide. Ten million to 20 million of the infected individuals develop disease per year. TB is a treatable disease, provided that it is diagnosed in a timely manner. The current TB diagnostic methods are subjective, inefficient, or not cost-effective. Antibody-based blood tests can be used efficiently and cost-effectively for TB diagnosis. A major challenge is that different TB patients generate antibodies against different antigens. Therefore, a multiplex immunoassay approach is needed. We have developed a multiplex panel of 28 M. tuberculosis antigen-coated microbeads. Plasma samples were obtained from over 300 pulmonary TB patients and healthy controls in a country where TB is endemic, Pakistan. Multiplex data were analyzed using computational tools by multivariate statistics, classification algorithms, and cluster analysis. The results of antibody profile-based detection, using 16 selected antigens, closely correlated with those of the sputum-based diagnostic methods (smear microscopy and culture) practiced in countries where TB is endemic. Multiplex microbead immunoassay had a sensitivity and specificity of approximately 90% and 80%, respectively. These antibody profiles could potentially be useful for the diagnosis of nonpulmonary TB, which accounts for approximately 20% of cases of disease. Since an automated, high-throughput version of this multiplex microbead immunoassay could analyze thousands of samples per day, it may be useful for the diagnosis of TB in millions of patients worldwide.

Suppressed type 1, type 2, and type 17 cytokine responses in active tuberculosis in children

Type 1 cytokine responses are known to play an important role in immunity to tuberculosis (TB) in children, although little is known about other factors that might be important. In addition, children are more prone to developing extrapulmonary manifestations of TB than adults. To identify the immune responses important both in control of infection and in extrapulmonary dissemination, we examined mycobacterium-specific cytokine responses of children with pulmonary TB (PTB) and extrapulmonary TB (ETB) and compared them with those of healthy control children (HC). No significant differences were found in the cytokine responses either with no stimulation or following mycobacterial-antigen (Ag) stimulation between children with PTB and ETB. On the other hand, children with active TB compared with HC showed markedly diminished production of type 1 (gamma interferon [IFN-γ] and tumor necrosis factor alpha [TNF-α]), 2 (interleukin 4 [IL-4] and IL-13), and 17 (IL-17A, IL-21, and IL-23)-associated cytokines with no stimulation and in response to mycobacterial antigens. This was not associated with significantly altered production of IL-10 or transforming growth factor β (TGF-β). Among children with ETB, those with neurologic involvement exhibited more significantly diminished Ag-driven IFN-γ and IL-17 production. Pediatric TB is characterized by diminished type 1, 2, and 17 cytokine responses, with the most profound diminution favoring development of neurologic TB, suggesting a crucial role for these cytokines in protection against pediatric tuberculosis.

Mycobacterium tuberculosis Complex Genotype Diversity and Drug Resistance Profiles in a Pediatric Population in Mexico

The aim of this study was to determine the frequency of drug resistance and the clonality of genotype patterns in M. tuberculosis clinical isolates from pediatric patients in Mexico (n = 90 patients from 19 states; time period—January 2002 to December 2003). Pulmonary disease was the most frequent clinical manifestation (71%). Children with systemic tuberculosis (TB) were significantly younger compared to patients with localized TB infections (mean 7.7 ± 6.2 years versus 15 ± 3.4 years P = 0.001). Resistance to any anti-TB drug was detected in 24/90 (26.7%) of the isolates; 21/90 (23.3%) and 10/90 (11.1%) were resistant to Isoniazid and Rifampicin, respectively, and 10/90 (11.1%) strains were multidrug-resistant (MDR). Spoligotyping produced a total of 55 different patterns; 12/55 corresponded to clustered isolates (n = 47, clustering rate of 52.2%), and 43/55 to unclustered isolates (19 patterns were designated as orphan by the SITVIT2 database). Database comparison led to designation of 36 shared types (SITs); 32 SITs (n = 65 isolates) matched a preexisting shared type in SITVIT2, whereas 4 SITs (n = 6 isolates) were newly created. Lineage classification based on principal genetic groups (PGG) revealed that 10% of the strains belonged to PGG1 (Bovis and Manu lineages). Among PGG2/3 group, the most predominant clade was the Latin-American and Mediterranean (LAM) in 27.8% of isolates, followed by Haarlem and T lineages. The number of single drug-resistant (DR) and multidrug-resistant (MDR-TB) isolates in this study was similar to previously reported in studies from adult population with risk factors. No association between the spoligotype, age, region, or resistance pattern was observed. However, contrary to a study on M. tuberculosis spoligotyping in Acapulco city that characterized a single cluster of SIT19 corresponding to the EAI2-Manila lineage in 70 (26%) of patients, not a single SIT19 isolate was found in our pediatric patient population. Neither did we find any shared type belonging to the EAI family which represents ancestral PGG1 strains within the M. tuberculosis complex. We conclude that the population structure of pediatric TB in our setting is different from the one prevailing in adult TB patient population of Guerrero.

Tag SNP polymorphism of CCL2 and its role in clinical tuberculosis in Han Chinese pediatric population

BACKGROUND

Chemokine (C-C motif) ligand 2 CCL2/MCP-1 is among the key signaling molecules of innate immunity; in particular, it is involved in recruitment of mononuclear and other cells in response to infection, including tuberculosis (TB) and is essential for granuloma formation.

METHODOLOGY/PRINCIPAL FINDINGS

We identified a tag SNP for the CCL2/MCP-1 gene (rs4586 C/T). In order to understand whether this SNP may serve to evaluate the contribution of the CCL2 gene to the expression of TB disease, we further analysed distribution of its alleles and genotypes in 301 TB cases versus 338 non-infected controls (all BCG vaccinated) representing a high-risk pediatric population of North China. In the male TB subgroup, the C allele was identified in a higher rate (P = 0.045), and, acting dominantly, was found to be a risk factor for clinical TB (P = 0.029). Homozygous TT genotype was significantly associated with lower CSF mononuclear leukocyte (ML) counts in patients with tuberculous meningitis (TBM) (P = 0.001).

CONCLUSIONS/SIGNIFICANCE

The present study found an association of the CCL2 tag SNP rs4586 C allele and pediatric TB disease in males, suggesting that gender may affect the susceptibility to TB even in children. The association of homozygous TT genotype with decreased CSF mononuclear leukocyte (ML) count not only suggests a clinical significance of this SNP, but indicates its potential to assist in the clinical assessment of suspected TBM, where delay is critical and diagnosis is difficult.

Immune reconstitution inflammatory syndrome due to Mycobacterium bovis Bacillus Calmette-Guerin in infants receiving highly active antiretroviral therapy: a call for universal perinatal rapid HIV testing prior to administration of BCG immunization of neonates

The evidence behind the World Health Organization guidelines that BCG vaccination should not be used in HIV-infected children is compelling. We report three cases of severe BCG-associated immune reconstitution syndrome in HIV-infected infants and describe measures available in developing countries that prevent inadvertent BCG immunization in these infants.

Impact of immigration on pulmonary tuberculosis in Spanish children: a three-decade review

BACKGROUND

Tuberculosis causes significant morbidity and mortality worldwide. In the last years, international travel and immigration have led to important changes in the epidemiology of this disease. Drug resistance has emerged as an important threat to tuberculosis control. Data regarding the impact of immigration and the incidence of drug-resistant strains in children are lacking.

METHODS

Retrospective review of patients diagnosed with pulmonary tuberculosis at La Paz Children's Hospital in a 30-year period. Data were collected with regard to the clinical, radiologic, microbiologic, and demographic characteristics of patients, and data from the 3 decades of the study were compared using chi test and Fisher exact test.

RESULTS

A total of 507 cases of tuberculosis were identified, 414 of which had pulmonary involvement. During the study, there was a significant decrease in tuberculous meningitis: 10.4% in 1978-1987, 5.6% in 1988-1997, and 2.9% in 1998-2007 (P < 0.05). The most frequent reason for a consultation was case contact investigation. The adult source case was identified in 64% of patients. We observed an increase in extrafamilial contacts (8% in 1978-1987 and 18% in 1998-2007, P < 0.01), including 4 cases of immigrant caretakers. Tuberculosis in immigrant children has increased with time: 2% in the period 1978-1987, 6% in 1988-1997, and 46% in 1998-2007 (P < 0.001). The primary resistance rate to isoniazid in our population was 6.5%.

CONCLUSIONS

Tuberculosis in our area continues to be a major health problem, especially among foreign-born children. As drug-resistant strains are increasing, initial therapy with 4 drugs is recommended in our population.

A review of tuberculosis-related referrals among children in Ireland

BACKGROUND

Immigration has been shown to have an increasingly important effect on the epidemiology of tuberculosis (TB) in developed countries.

AIM

To review patterns of TB-related referrals to a paediatric infectious diseases clinic.

METHODS

Retrospective chart review of TB-related referrals of children attending the Rainbow Clinic at OLCHC between 2003-2005.

RESULTS

Forty-seven children were assessed: 18 referred from public health clinics, 5 from general practitioners, and 24 from paediatricians. Most common reason for referral was history of TB exposure (60%). Eighteen (38%) were female, 29 (62%) were male. Thirteen (28%) had latent TB, and 17 (36%) had active disease. Of children with TB disease, 25 (83%) were Caucasian Irish, and the remainder was African. Twenty-five children completed TB treatment and were discharged, and 2 (7%) were lost to follow-up.

CONCLUSION

Our study highlights the problem of TB in children, the majority of whom are native to this country.

Changes in tuberculin sensitivity among first-grade students of elementary schools in Evros, Greece due to immigration

OBJECTIVE

To investigate the tuberculin sensitivity trends among first-grade students of elementary schools tested according to the Greek national school-based screening and vaccination programme.

STUDY DESIGN

Retrospective analysis of tuberculin skin test (TST) results from 1988 to 2004 in unvaccinated first-grade students in Evros, Greece.

METHODS

All 6-7-year-old children who were unvaccinated for tuberculosis were tested by a highly experienced team. This study tested whether gender (male vs female), national origin (native vs foreign-born children) and place of residence (urban vs semi-urban vs rural) correlated with tuberculin reaction positivity.

RESULTS

In total, 8588 children (47.1% girls) were tested. Tuberculin reaction positivity was independent of gender. The difference in TST positivity between native and foreign-born children between 1993 and 2004 was highly significant, with substantially more foreign-born children having a positive Mantoux test (P<0.0001). The percentage of children with a positive TST peaked at 13% in 1995 due to initial admission of foreign-born children, originating from countries of the former Soviet Union, into the Greek educational system. In addition, a positive Mantoux test was more common among children living in rural (8.1%) and semi-urban (6.4%) areas compared with children living in urban areas (3.5%, P<0.0001).

CONCLUSION

The increase in TST positivity noted was due to admission of foreign-born children into the Greek educational system. School-based tuberculosis screening programmes should continue in Greece because the prevalence of tuberculosis appears to show substantial variation between years.

Polymorphic variation in TIRAP is not associated with susceptibility to childhood TB but may determine susceptibility to TBM in some ethnic groups

Host recognition of mycobacterial surface molecules occurs through toll like receptors (TLR) 2 and 6. The adaptor protein TIRAP mediates down stream signalling of TLR2 and 4, and polymorphisms in the TIRAP gene (TIRAP) have been associated with susceptibility and resistance to tuberculosis (TB) in adults. In order to investigate the role of polymorphic variation in TIRAP in childhood TB in South Africa, which has one of the highest TB incidence rates in the world, we screened the entire open reading frame of TIRAP for sequence variation in two cohorts of childhood TB from different ethnic groups (Xhosa and mixed ancestry). We identified 13 SNPs, including seven previously unreported, in the two cohorts, and found significant differences in frequency of the variants between the two ethnic groups. No differences in frequency between individual SNPs or combinations were found between TB cases and controls in either cohort. However the 558C→T SNP previously associated with TB meningitis (TBM) in a Vietnamese population was found to be associated with TBM in the mixed ancestry group. Polymorphisms in TIRAP do not appear to be involved in childhood TB susceptibility in South Africa, but may play a role in determining occurrence of TBM.

Detection and molecular characterization of 9,000-year-old Mycobacterium tuberculosis from a Neolithic settlement in the Eastern Mediterranean

Background

Mycobacterium tuberculosis is the principal etiologic agent of human tuberculosis. It has no environmental reservoir and is believed to have co-evolved with its host over millennia. This is supported by skeletal evidence of the disease in early humans, and inferred from M. tuberculosis genomic analysis. Direct examination of ancient human remains for M. tuberculosis biomarkers should aid our understanding of the nature of prehistoric tuberculosis and the host/pathogen relationship.

Methodology/Principal Findings

We used conventional PCR to examine bone samples with typical tuberculosis lesions from a woman and infant, who were buried together in the now submerged site of Atlit-Yam in the Eastern Mediterranean, dating from 9250-8160 years ago. Rigorous precautions were taken to prevent contamination, and independent centers were used to confirm authenticity of findings. DNA from five M tuberculosis genetic loci was detected and had characteristics consistent with extant genetic lineages. High performance liquid chromatography was used as an independent method of verification and it directly detected mycolic acid lipid biomarkers, specific for the M. tuberculosis complex.

Conclusions/Significance

Human tuberculosis was confirmed by morphological and molecular methods in a population living in one of the first villages with evidence of agriculture and animal domestication. The widespread use of animals was not a source of infection but may have supported a denser human population that facilitated transmission of the tubercle bacillus. The similarity of the M. tuberculosis genetic signature with those of today gives support to the theory of a long-term co-existence of host and pathogen.

Paediatric tuberculosis

Tuberculosis continues to cause an unacceptably high toll of disease and death among children worldwide, particularly in the wake of the HIV epidemic. Increased international travel and immigration have led to a rise in childhood tuberculosis rates even in traditionally low burden, industrialised settings, and threaten to promote the emergence and spread of multidrug-resistant strains. Whereas intense scientific and clinical research efforts into novel diagnostic, therapeutic, and preventive interventions have focused on tuberculosis in adults, childhood tuberculosis has been relatively neglected. However, children are particularly vulnerable to severe disease and death following infection, and those with latent infection become the reservoir for future transmission following disease reactivation in adulthood, fuelling future epidemics. Further research into the epidemiology, immune mechanisms, diagnosis, treatment, and prevention of childhood tuberculosis is urgently needed. Advances in our understanding of tuberculosis in children would provide insights and opportunities to enhance efforts to control this disease.

Diagnosing mycobacterial lymphadenitis in children using fine needle aspiration biopsy: cytomorphology, ZN staining and autofluorescence -- making more of less

Although the incidence of TB has stabilized or declined in most world regions, it is increasing in Africa, Southeast Asia, and the Eastern Mediterranean, fuelled by the HIV pandemic. More than 4,000 people died daily from TB-related illnesses in 2005. TB is a major cause of childhood morbidity and mortality in these developing countries, and there is an urgent need for rapid and definitive modalities for mycobacterial diagnosis in children. This prospective study in Tygerberg Hospital, Cape Town, South Africa, evaluates the ability of fine needle aspiration biopsy (FNAB) to diagnose mycobacterial lymphadenitis in children, using cytomorphology, autofluorescence on Papanicolaou stained smears, Ziehl-Nielsen (ZN) staining and/or culture. FNABs were performed on 200 children, and 25 (12.5%) aspirates were inadequate. Cultures were positive in 79/175 (45%); Mycobacterium tuberculosis was identified in 61 and Mycobacterium bovis BCG in 18 cases. Using culture as the gold standard, the concordance of the different techniques was as follows: cytomorphology 70%, ZN staining 73%, and autofluorescence 68%. Using an alternative gold standard (culture positive and/or suggestive cytomorphology plus positive autofluorescence or ZN smear), the "true" diagnostic performance of the various techniques was as follows: cytomorphology-sensitivity 78%, specificity 91%, positive predictive value (PPV) 93%, ZN staining - sensitivity 62%%, specificity 97%, PPV 97%; autofluorescence-sensitivity 67%, specificity 97%, PPV 97%; and culture-sensitivity 75%, specificity 100%, and PPV 100%. FNAB was shown to provide a rapid and definitive diagnosis in the majority of cases of suspected tuberculous lymphadenitis in children, based on cytomorphology and identification of the organism.

Symptom-based screening of child tuberculosis contacts: improved feasibility in resource-limited settings

OBJECTIVE

National tuberculosis programs in tuberculosis-endemic countries rarely implement active tracing and screening of child tuberculosis contacts, mainly because of resource constraints. We aimed to evaluate the safety and feasibility of applying a simple symptom-based approach to screen child tuberculosis contacts for active disease.

METHODS

We conducted a prospective observational study from January through December 2004 at 3 clinics in Cape Town, South Africa. All of the children <5 years old in household contact with an adult tuberculosis source case were assessed by documenting current symptoms and tuberculin skin test and chest radiograph results.

RESULTS

During the study period, 357 adult tuberculosis cases were identified; 195 cases (54.6%) had sputum smear and/or culture positive results and were in household contact with children aged <5 years. Complete information was available for 252 of 278 children; 176 (69.8%) were asymptomatic at the time of screening. Tuberculosis treatment was administered to 33 (13.1%) of 252; 27 were categorized as radiologically "certain tuberculosis," the majority (n = 22) of which had uncomplicated hilar adenopathy. The negative predictive value of symptom-based screening varied according to the case definition used, with 95.5% including all of the children treated for tuberculosis and 97.1% including only those with radiologically "certain tuberculosis."

CONCLUSIONS

Our findings support current World Health Organization recommendations, demonstrating that symptom-based screening of child tuberculosis contacts should improve feasibility in resource-limited settings and seems to be safe.