A systematic review of clinical diagnostic systems used in the diagnosis of tuberculosis in children

Factors associated with tuberculosis care-seeking and diagnostic delays among childhood pulmonary tuberculosis in Zhejiang Province, China: a 10-year retrospective study

We conducted a retrospective study to investigate risk factors for tuberculosis care-seeking delay and diagnostic delays among pediatric pulmonary tuberculosis cases in Zhejiang Province from 2013 to 2022. Among 1274 cases, 49.61% experienced tuberculosis care-seeking delays (> 14 days from symptom onset to first hospital visit) and 14.91% faced diagnostic delays (> 14 days from initial consultation to diagnosis). The proportion of care-seeking delays ranged from 37.42 to 64.89%, while diagnostic delay fluctuated from 6.11 to 21.02%. Urban residence (OR = 0.78, 95% CI 0.62-0.98, P = 0.030), first visiting a municipal-level hospital (OR = 0.57, 95% CI 0.45-0.72, P < 0.001), and diagnostic method (OR = 0.66, 95%CI 0.52-0.84, P < 0.001) were associated with tuberculosis care-seeking delay, whereas first visiting a municipal-level hospital (OR = 2.05, 95% CI 1.49-2.80, P < 0.001) was linked to diagnostic delay. Further analysis using a 28-day cutoff point revealed that children aged 0-4 years, those from migrant populations, laboratory-confirmed patients, and those who first visited a county-level hospital were more likely to experience delays in seeking tuberculosis care. Thus, society should pay more attention to the health of rural, migrant, and 0-4-year-old children, as they are at higher risk of experiencing tuberculosis care-seeking delays.

Diagnostic accuracy of clinical diagnostic scoring systems for childhood tuberculosis: a systematic review and meta-analysis protocol

INTRODUCTION

Diagnosis of childhood tuberculosis (TB) poses several challenges. Therefore, clinical signs and symptoms, radiological studies, laboratory examinations, point-based scoring systems or diagnostic algorithms have been developed to improve diagnostic yields in this population. However, there are limited data on the diagnostic test accuracy of paediatric TB scoring systems. Therefore, this systematic review and meta-analysis aims to synthesise the available evidence on the diagnostic accuracy of childhood TB diagnostic scoring systems.

METHODS AND ANALYSIS

This protocol describes a systematic review, developed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses of Diagnostic Test Accuracy. We will conduct a comprehensive literature search for relevant articles in the following databases: PubMed, CINAHL, Embase, Scopus and Cochrane Databases. The eligibility criteria for studies will be formulated based on the Participants (Population), Index Test, Comparator Test and Target Condition criteria for the review question. The index test will be defined as any attempt to diagnose childhood TB using either a scoring system or a diagnostic algorithm, whereas a composite reference standard will be used as a reference standard. This will include any attempt to confirm diagnosis of TB. Where bacteriological confirmation is not obtained and there are at least two of the following features: chest radiograph consistent with TB, immunological evidence of Mycobacterium tuberculosis infection and/or positive response to TB treatment will also be considered. The QUADAS-2 Tool will be used to assess the quality of the studies. The diagnostic accuracy measures (ie, sensitivity, specificity, negative predictive and positive predictive values) will be pooled with the random-effects or fixed-effects models, as appropriate. All statistical analyses will be performed using the Review Manager V.5.4.

ETHICS AND DISSEMINATION

This research is exempt from ethics approval given that this is a protocol for a systematic review, which uses published data. The findings from this review will be disseminated through peer-reviewed publications and scientific conferences.

PROSPERO REGISTRATION NUMBER

CRD42022367049.

Development of a Clinical Prediction Score Including Monocyte-to-Lymphocyte Ratio to Inform Tuberculosis Treatment Among Children With HIV: A Multicountry Study

Background

Clinical pediatric tuberculosis (TB) diagnosis may lead to overdiagnosis particularly among children with human immunodeficiency virus (CHIV). We assessed the performance of monocyte-lymphocyte ratio (MLR) as a diagnostic biomarker and constructed a clinical prediction score to improve specificity of TB diagnosis in CHIV with limited access to microbiologic testing.

Methods

We pooled data from cohorts of children aged ≤13 years from Vietnam, Cameroon, and South Africa to validate the use of MLR ≥0.378, previously found as a TB diagnostic marker among CHIV. Using multivariable logistic regression, we created an internally validated prediction score for diagnosis of TB disease in CHIV.

Results

The combined cohort had 601 children (median age, 1.9 [interquartile range, 0.9-5.3] years); 300 (50%) children were male, and 283 (47%) had HIV. Elevated MLR ≥0.378 had sensitivity of 36% (95% confidence interval [CI], 23%-51%) and specificity of 79% (95% CI, 71%-86%) among CHIV in the validation cohort. A model using MLR ≥0.28, age ≥4 years, tuberculin skin testing ≥5 mm, TB contact history, fever >2 weeks, and chest radiograph suggestive of TB predicted active TB disease in CHIV with an area under the receiver operating characteristic curve of 0.85. A prediction score of ≥5 points had a sensitivity of 94% and specificity of 48% to identify confirmed TB, and a sensitivity of 82% and specificity of 48% to identify confirmed and unconfirmed TB groups combined.

Conclusions

Our score has comparable sensitivity and specificity to algorithms including microbiological testing and should enable clinicians to rapidly initiate TB treatment among CHIV when microbiological testing is unavailable.

Diagnostic Challenges in Childhood Pulmonary Tuberculosis-Optimizing the Clinical Approach

The management of childhood tuberculosis (TB) is hampered by the low sensitivity and limited accessibility of microbiological testing. Optimizing clinical approaches is therefore critical to close the persistent gaps in TB case detection and prevention necessary to realize the child mortality targets of the End TB Strategy. In this review, we provide practical guidance summarizing the evidence and guidelines describing the use of symptoms and signs in decision making for children being evaluated for either TB preventive treatment (TPT) or TB disease treatment in high-TB incidence settings. Among at-risk children being evaluated for TPT, a symptom screen may be used to differentiate children who require further investigation for TB disease before receiving TPT. For symptomatic children being investigated for TB disease, an algorithmic approach can inform which children should receive TB treatment, even in the absence of imaging or microbiological confirmation. Though clinical approaches have limitations in accuracy, they are readily available and can provide valuable guidance for decision making in resource-limited settings to increase treatment access. We discuss the trade-offs in using them to make TB treatment decisions.

Development of a Treatment-decision Algorithm for Human Immunodeficiency Virus-uninfected Children Evaluated for Pulmonary Tuberculosis

BACKGROUND

Limitations in the sensitivity and accessibility of diagnostic tools for childhood tuberculosis contribute to the substantial gap between estimated cases and cases notified to national tuberculosis programs. Thus, tools to make accurate and rapid clinical diagnoses are necessary to initiate antituberculosis treatment in more children.

METHODS

We analyzed data from a prospective cohort of children <13 years old being routinely evaluated for pulmonary tuberculosis in Cape Town, South Africa, from March 2012 to November 2017. We developed a regression model to describe the contributions of baseline clinical evaluation to the diagnosis of tuberculosis using standardized, retrospective case definitions. We included baseline chest radiographic and Xpert MTB/RIF assay results to the model to develop an algorithm with ≥90% sensitivity in predicting tuberculosis.

RESULTS

Data from 478 children being evaluated for pulmonary tuberculosis were analyzed (median age, 16.2 months; interquartile range, 9.8-30.9 months); 242 (50.6%) were retrospectively classified with tuberculosis, bacteriologically confirmed in 104 (43.0%). The area under the receiver operating characteristic curve for the final model was 0.87. Clinical evidence identified 71.4% of all tuberculosis cases in this cohort, and inclusion of baseline chest radiographic results increased the proportion to 89.3%. The algorithm was 90.1% sensitive and 52.1% specific, and maintained a sensitivity of >90% among children <2 years old or with low weight for age.

CONCLUSIONS

Clinical evidence alone was sufficient to make most clinical antituberculosis treatment decisions. The use of evidence-based algorithms may improve decentralized, rapid treatment initiation, reducing the global burden of childhood mortality.

Xpert® MTB/RIF assay testing on stool for the diagnosis of paediatric pulmonary TB in Tanzania

SETTING

Six health facilities in Dar es Salaam, Tanzania.

OBJECTIVE

To evaluate the use of stool specimens in the diagnostic workup of paediatric TB using the Xpert^® MTB/RIF assay.

DESIGN

Between December 2018 and May 2019, we performed a cross-sectional diagnostic study of children aged between 1 month and 14 years with presumptive TB. A single stool specimen was tested using Xpert. The result was compared with the reference microbiological standard for respiratory or gastric specimens tested using Xpert and/or solid culture. The sensitivity, specificity and predictive values of stool Xpert assay were assessed.

RESULTS

A total of 225 children with a median age of 2.17 years (IQR 1.16-5.19) were enrolled; 165/225 (73.3%) were aged <5 years. Of 225 children, 8 (3.6%) were diagnosed with TB as they were culture- or Xpert-positive on sputum/gastric aspirate. The stool Xpert assay showed a sensitivity of 62.5% (95% CI 25-92) and specificity of 100% (95% CI 98-100) against the reference standard.

CONCLUSION

Use of the Xpert assay on stool specimens had a moderate sensitivity and high specificity in the diagnosis of pulmonary TB in children. Our data adds to the body of evidence for the use of Xpert assay on stool as a non-respiratory specimen to complement conventional methods used to diagnose the disease.

Development and performance of CUHAS-ROBUST application for pulmonary rifampicin-resistance tuberculosis screening in Indonesia

BACKGROUND AND OBJECTIVES

Diagnosis of Pulmonary Rifampicin Resistant Tuberculosis (RR-TB) with the Drug-Susceptibility Test (DST) is costly and time-consuming. Furthermore, GeneXpert for rapid diagnosis is not widely available in Indonesia. This study aims to develop and evaluate the CUHAS-ROBUST model performance, an artificial-intelligence-based RR-TB screening tool.

METHODS

A cross-sectional study involved suspected all type of RR-TB patients with complete sputum Lowenstein Jensen DST (reference) and 19 clinical, laboratory, and radiology parameter results, retrieved from medical records in hospitals under the Faculty of Medicine, Hasanuddin University Indonesia, from January 2015-December 2019. The Artificial Neural Network (ANN) models were built along with other classifiers. The model was tested on participants recruited from January 2020-October 2020 and deployed into CUHAS-ROBUST (index test) application. Sensitivity, specificity, and accuracy were obtained for assessment.

RESULTS

A total of 487 participants (32 Multidrug-Resistant/MDR 57 RR-TB, 398 drug-sensitive) were recruited for model building and 157 participants (23 MDR and 21 RR) in prospective testing. The ANN full model yields the highest values of accuracy (88% (95% CI 85-91)), and sensitivity (84% (95% CI 76-89)) compare to other models that show sensitivity below 80% (Logistic Regression 32%, Decision Tree 44%, Random Forest 25%, Extreme Gradient Boost 25%). However, this ANN has lower specificity among other models (90% (95% CI 86-93)) where Logistic Regression demonstrates the highest (99% (95% CI 97-99)). This ANN model was selected for the CUHAS-ROBUST application, although still lower than the sensitivity of global GeneXpert results (87.5%).

CONCLUSION

The ANN-CUHAS ROBUST outperforms other AI classifiers model in detecting all type of RR-TB, and by deploying into the application, the health staff can utilize the tool for screening purposes particularly at the primary care level where the GeneXpert examination is not available.

TRIAL REGISTRATION

NCT04208789.

Advances in the diagnosis of pulmonary tuberculosis in children

Major challenges still exist in the accurate diagnosis of tuberculosis in children. Algorithms based on clinical and radiological features remain in widespread use despite poor performance. Newer molecular diagnostics allow for rapid identification of TB and detection of drug-resistance in a subset of children, but lack sensitivity. Molecular testing of multiple specimens, including non-traditional specimen types, such as nasopharyngeal aspirates and stool and urine, may improve sensitivity, but the optimal combination of specimens requires further research. Novel tests under development or evaluation include a urine lipoarabinomannan test with improved sensitivity and a range of biomarkers measured from stimulated or unstimulated peripheral blood.

Diagnosis of pulmonary tuberculosis in children and adolescents: comparison of two versions of the Brazilian Ministry of Health scoring system

The aim of this study was to evaluate the concordance between two versions of the scoring system (2011 and 2019), recommended by the Brazilian Ministry of Health, for the diagnosis of pulmonary tuberculosis (PTB) in children and adolescents. A retrospective descriptive study was performed to assess the medical records of children and adolescents with PTB, in TB units from Brazilian cities located in Rio de Janeiro, Minas Gerais, and Parana States, from January 1 st , 2004, to December 1 st , 2018. Patients aged 0 to 18 years old with a diagnosis of PTB were included. The comparison between the two scoring systems showed a moderate concordance according to the κ coefficient value = 0.625. Fourteen patients showed a reduction in the TB score, going from 30 points in the 2011, to 25 points or less in the 2019 one. Seventy one percent of these 14 patients had radiological changes suggestive of PTB and 86% had tuberculin skin tests greater than 10 mm. The study concluded that a moderate agreement was observed between the 2011 and 2019 scoring systems, with an increase in the number of patients scoring 25 points or less in 2019, which can eventually hinder the diagnosis of PTB.

Evaluation of pulmonary tuberculosis diagnostic tests in children and adolescents at a pediatric reference center

Introduction

This study evaluates the performance of individual and combinations tests used for pediatric tuberculosis diagnosis at a reference center.

Materials and Methods

Diagnostic test outcomes from children with presumed pulmonary tuberculosis evaluated from January 2005 - July 2010 were compared to a standard diagnosis made by an expert panel of physicians.

Results

Presence of at least one sign/symptom, history of contact, or abnormal chest X-ray (aCXR) individually showed the highest sensitivity (85.7%). While the combination of history of contact, at least one sign/symptom, positive tuberculin skin test, and aCXR had low sensitivity of 20%, but the specificity and a positive predictive value were 100%, respectively. The combination of tests used in the International Union Against Tuberculosis and Lung Disease and the Brazilian Ministry of Health systems showed sensitivity of 28.6% and 71.4% and specificity of 95.8% and 97.0%, respectively.

Conclusions

In the absence of a gold standard, the combination of clinical history, tuberculin skin test, and aCXR, as well as the Brazilian scoring system serve as simple, low-cost approach that can be used for pediatric TB diagnosis by first-contact care providers.

QuantiFERON-TB Gold In-Tube test performance in a large pediatric population investigated for suspected tuberculosis infection

BACKGROUND

The performance of QuantiFERON-TB Gold In-Tube (QTF-IT) in children is under debate, especially in those under 5 years of age. Moreover, interpretation of discordant QFT-IT/Tuberculin-Skin-Test (TST) results remains controversial. This study aims at studying the sensitivity of QFT-IT and TST in children with active TB cases and exploring risk factors associated with discordant TST+/QFT-IT-.

METHODS

Children consecutively referred to one single pediatric center between 2010 and 2017 for suspected tuberculosis infection (TB) were enrolled. All children underwent clinical evaluation, TST and QFT-IT. Sensitivity of QFT-IT and TST in active TB cases and risk factors associated with discordant TST+/QFT-IT- results were assessed. Uni- and multi-variate logistic regression analyses were performed.

RESULTS

Overall, 4631 children (median age 5.67 years) were enrolled, and 205 active TB cases were diagnosed (83 microbiologically confirmed). A high QFT-IT sensitivity was observed in children between 2 and 4 years of age (95.0%; 95%CI: 85.4-100) and in those between 5 and 18 years (89.1%; 95%CI:79.2-99.2) with microbiologically confirmed active TB. However, sensitivity was suboptimal in children younger than 2 years (84.6%; 95%CI: 65.0-100). Independent risk factors associated with discordant TST+/QFT-IT- results in children with latent tuberculosis infection (LTBI) were previous BCG vaccination (aOR:2.18; 95%CI:1.33-3.58; p = 0.002), age <2 years vs. 5-18 years (aOR:7.54; 95%CI:2.52-22.59; p < 0.0001), age 2-4 years vs. 5-18 years (aOR:4.63; 95%CI:2.66-8.06; p < 0.0001), and investigation for screening rather than for contact with a suspected or confirmed case (aOR:3.58; 95%CI:2.30-5.59; p < 0.0001).

CONCLUSION

Our data suggest that QFT-IT might be used as unique assay in children over 2 years of age investigated for recent immigration/adoption screening and in cases of recent low risk TB contact. This approach could considerably reduce the number of children undergoing pharmacological treatment. Conversely, both tests are recommended in cases of strong clinical suspicion or high risk TB contact in children less than 5 years of age, in order to avoid misdiagnosis.

Quality of care in childhood tuberculosis diagnosis at primary care clinics in Kampala, Uganda

OBJECTIVE

To assess the quality of routine childhood tuberculosis (TB) evaluation in Kampala, Uganda.

SETTING AND DESIGN

This was a cross-sectional study of children aged <15 years attending six government-run clinics from November 2015 to December 2016. Clinicians completed a standardized patient record form for all child visits. We assessed the following performance indicators of TB evaluation developed based on the Desk Guide of the International Union Against Tuberculosis and Lung Disease, an evidence-based decision aid on childhood TB diagnosis and management for clinicians: proportion screened for TB symptoms or contact history, proportion referred for laboratory evaluation if screen-positive, and proportion treated for TB if test-positive or meeting clinical criteria.

RESULTS

Of 24 566 consecutive children enrolled, 11 614 (47%) were fully screened for TB symptoms. Of 1747 (15%) children who screened positive, 360 (21%) had sputum examined, including 159 (44%) using smear microscopy, 244 (67%) using Xpert® MTB/RIF, and 52 (14%) using both techniques. Treatment was initiated in 18/20 (80%) children who tested positive. An additional 65 screen-positive children met the clinical criteria for TB; none were initiated on treatment.

CONCLUSIONS

Large gaps exist along the pathway to diagnosis and treatment of childhood TB. There is an urgent need for enhanced implementation of evidence-based approaches to TB diagnosis to improve outcomes in childhood TB.

Diagnostic practices and estimated burden of tuberculosis among children admitted to 13 government hospitals in Kenya: An analysis of two years' routine clinical data

BACKGROUND

True burden of tuberculosis (TB) in children is unknown. Hospitalised children are low-hanging fruit for TB case detection as they are within the system. We aimed to explore the process of recognition and investigation for childhood TB using a guideline-linked cascade of care.

METHODS

This was an observational study of 42,107 children admitted to 13 county hospitals in Kenya from 01Nov 15-31Oct 16, and 01Nov 17-31Oct 18. We estimated those that met each step of the cascade, those with an apparent (or "Working") TB diagnosis and modelled associations with TB tests amongst guideline-eligible children.

RESULTS

23,741/42,107 (56.4%) met step 1 of the cascade (≥2 signs and symptoms suggestive of TB). Step 2(further screening of history of TB contact/full respiratory exam) was documented in 14,873/23,741 (62.6%) who met Step 1. Step 3(chest x-ray or Mantoux test) was requested in 2,451/14,873 (16.5%) who met Step 2. Step 4(≥1 bacteriological test) was requested in 392/2,451 (15.9%) who met Step 3. Step 5("Working TB" diagnosis) was documented in 175/392 (44.6%) who met Step 4. Factors associated with request of TB tests in patients who met Step 1 included: i) older children [AOR 1.19(CI 1.09-1.31)]; ii) co-morbidities of HIV, malnutrition or pneumonia [AOR 3.81(CI 3.05-4.75), 2.98(CI 2.69-3.31) and 2.98(CI 2.60-3.40) respectively]; iii) sicker children, readmitted/referred [AOR 1.24(CI 1.08-1.42) and 1.15(CI 1.04-1.28) respectively]. "Working TB" diagnosis was made in 2.9%(1,202/42,107) of all admissions and 0.2%(89/42,107) were bacteriologically-confirmed.

CONCLUSIONS

More than half of all paediatric admissions had symptoms associated with TB and nearly two-thirds had more specific history documented. Only a few amongst them got TB tests requested. TB was diagnosed in 2.9% of all admissions but most were inadequately investigated. Major challenges remain in identifying and investigating TB in children in hospitals with access to Xpert MTB/RIF and a review is needed of existing guidelines.

Epidemiological aspects, clinical manifestations, and prevention of pediatric tuberculosis from the perspective of the End TB Strategy

Tuberculosis continues to be a public health priority in many countries. In 2015, tuberculosis killed 1.4 million people, including 210,000 children. Despite the recent progress made in the control of tuberculosis in Brazil, it is still one of the countries with the highest tuberculosis burdens. In 2015, there were 69,000 reported cases of tuberculosis in Brazil and tuberculosis was the cause of 4,500 deaths in the country. In 2014, the World Health Organization approved the End TB Strategy, which set a target date of 2035 for meeting its goals of reducing the tuberculosis incidence by 90% and reducing the number of tuberculosis deaths by 95%. However, to achieve those goals in Brazil, there is a need for collaboration among the various sectors involved in tuberculosis control and for the prioritization of activities, including control measures targeting the most vulnerable populations. Children are highly vulnerable to tuberculosis, and there are particularities specific to pediatric patients regarding tuberculosis development (rapid progression from infection to active disease), prevention (low effectiveness of vaccination against the pulmonary forms and limited availability of preventive treatment of latent tuberculosis infection), diagnosis (a low rate of bacteriologically confirmed diagnosis), and treatment (poor availability of child-friendly anti-tuberculosis drugs). In this review, we discuss the epidemiology, clinical manifestations, and prevention of tuberculosis in childhood and adolescence, highlighting the peculiarities of active and latent tuberculosis in those age groups, in order to prompt reflection on new approaches to the management of pediatric tuberculosis within the framework of the End TB Strategy.

A comparison of tuberculosis diagnostic systems in a retrospective cohort of HIV-infected children in Rio de Janeiro, Brazil

Objectives:

The diagnosis of pediatric tuberculosis (TB) presents many challenges, and is further complicated in HIV-infected patients. While many diagnostic systems have been proposed, there is no pediatric TB diagnosis gold standard. The outcomes of four TB diagnostic systems in HIV-infected children were compared in this study.

Methods:

A retrospective cohort study was conducted at a TB/HIV reference hospital in Rio de Janeiro. HIV-infected pediatric patients evaluated for TB from 1998 to 2010 were reassessed using four diagnostic systems: Kenneth Jones, 1969; Tidjani, 1986; Ben Marais, 2006; Brazilian Ministry of Health, 2010. Results were compared to standardized diagnoses made by an expert panel of physicians.

Results:

Of the 121 patients in the study cohort, the expert panel diagnosed 64 as TB and 57 as not TB cases. The Tidjani system showed the highest diagnostic accuracy, with and without the inclusion of microbiological data. The Tidjani and Kenneth Jones systems produced fewer false-positives, and the Ben Marais and Ministry of Health fewer false-negatives. Across systems, there was little agreement between TB diagnoses.

Conclusions:

In HIV-infected pediatric patients, the Ben Marais and Ministry of Health systems are useful for TB diagnostic screening, whereas the Tidjani and Kenneth Jones systems are best used in a reference center setting.

The Diagnostic Value of Urine Lipoarabinomannan (LAM) Antigen in Childhood Tuberculosis

INTRODUCTION

Diagnosis of Tuberculosis (TB) in children is difficult because the clinical presentation is not specific, the chest X-ray interpretation has low accuracy and sputum sample is difficult to obtain. Antigen detection test such as rapid urine LAM is a non-invasive alternative for diagnosing TB . Lipoarabinomannan (LAM) is the main component of M.tuberculosis cell wall.

AIM

To determine the diagnostic value of urinary LAM antigen for diagnosis of childhood TB.

MATERIALS AND METHODS

In the present cross-sectional study, subjects were included using consecutive sampling method. All the children aged 0-14 years Suspected of pulmonary or extra pulmonary TB suffering from cough more than two weeks, fever without clear aetiology, loss of body weight or poor weight gain, fatigue, malaise, chronic lymph node enlargement, spine angulation, joint swelling and had history of contact with positive sputum smear adult TB patient were enrolled in the study. Pulmonary and extra pulmonary diagnosis was based on clinical presentation, Tuberculin Skin Test (TST), chest X-ray, Acid Fast Bacillus (AFB) staining and or sputum culture. Urinary LAM level was measured by using Enzyme-Linked Immunosorbent Assay (ELISA). Cut off value and Area Under the Curve (AUC) were determined using ROC statistical analysis (SPSS 21.0). Sensitivity and specificity was measured from 2x2 cross table.

RESULTS

Out of 61 subjects suspected as TB, 49 (80.3%) were eventually diagnosed with TB. Of those diagnosed with TB, 21 (42.9%) were microbiologically confirmed cases either by sputum microscopy (34.7%) or culture (8.2%), whereas 28 subjects were unconfirmed cases (57.1%). The urinary LAM level was higher in subjects with TB (1.80+1.02) mg/l compared to non-TB group (0.46+0.3) mg/l; p<0.001(independent t-test). Urine LAM had 83% sensitivity and 85% specificity with cut off value 0.98 mg/l using microbiological and clinical confirmation as standard reference and 33% sensitivity and 60% specificity with cut off value 1.69 mg/l using microbiological confirmation only.

CONCLUSION

Urinary LAM has good diagnostic value for childhood TB diagnosis.

Recommendations for the diagnosis of pediatric tuberculosis

Tuberculosis (TB) is still the world's second most frequent cause of death due to infectious diseases after HIV infection, and this has aroused greater interest in identifying and managing exposed subjects, whether they are simply infected or have developed one of the clinical variants of the disease. Unfortunately, not even the latest laboratory techniques are always successful in identifying affected children because they are more likely to have negative cultures and tuberculin skin test results, equivocal chest X-ray findings, and atypical clinical manifestations than adults. Furthermore, they are at greater risk of progressing from infection to active disease, particularly if they are very young. Consequently, pediatricians have to use different diagnostic strategies that specifically address the needs of children. This document describes the recommendations of a group of scientific societies concerning the signs and symptoms suggesting pediatric TB, and the diagnostic approach towards children with suspected disease.

Active Tuberculosis in HIV-Exposed Tanzanian Children up to 2 years of Age: Early-Life Nutrition, Multivitamin Supplementation and Other Potential Risk Factors

BACKGROUND

Over half a million children worldwide develop active tuberculosis (TB) each year. Early-life nutritional exposures have rarely been examined in relation to pediatric TB among HIV-exposed children. We therefore investigated independent associations of early-life nutritional exposures with active TB among HIV-exposed children up to 2 years of age.

METHODS

Participants were children from a randomized controlled multivitamin supplementation trial conducted in Dar es Salaam, Tanzania, from August 2004 to May 2008, who received daily multivitamin supplements or placebo for 24 months.

RESULTS

Lower mean corpuscular volumes [relative risks (RR): 0.48, 95% confidence interval (CI): 0.27, 0.87] and higher birth weights (RR: 0.61, 95% CI: 0.37, 0.99) were protective against active TB, whereas multivitamin supplementation was not associated with TB risk (RR: 0.87, 95% CI: 0.65, 1.16).

CONCLUSIONS

Knowledge of nutrition-related risk and protective factors for TB in HIV-exposed children could enhance preventive and case-finding activities in this population, contributing to efforts to reduce the global TB burden.

Understanding NIH clinical case definitions for pediatric intrathoracic TB by applying them to a clinical trial

SETTING

Standardized clinical case definitions represent the best option for pediatric tuberculosis (TB) disease diagnosis and classification.

OBJECTIVE

To apply published guidelines for intrathoracic TB classification for use in reporting diagnostic studies with passive case finding to presumed TB patients from International Maternal Pediatric Adolescent AIDS Clinical Trials P1041, a trial of isoniazid prophylaxis in healthy human immunodeficiency virus exposed, bacille Calmette-Guérin vaccinated infants which employed active surveillance to assess a novel application of these guidelines in this setting.

METHODS

P1041 presumed TB patients were retrospectively cross-classified by protocol-defined and National Institutes of Health (NIH) classifications, and agreement was assessed.

RESULTS

Of 219 TB suspects, 166 had signs/symptoms, with 158 considered TB (21 confirmed, 92 probable, 45 possible) and 8 not TB (6 TB unlikely, 2 alternative diagnoses). Weight loss and failure to thrive represented the majority of the observed signs/symptoms. Among those with signs/symptoms, agreement between definitions was poor. Furthermore, 53 TB presumptives were without signs/symptoms, including 33 classified by the P1041 protocol as TB.

CONCLUSION

Poor agreement between P1041 and NIH classifications reflects cases identified through active vs. passive surveillance, the latter reflecting the intended use of NIH definitions. Given the interest in standardized definitions for broader application, future efforts could focus on expanding TB disease classification to presumed TB patients identified through active surveillance.

Patching the gaps towards the 90-90-90 targets: outcomes of Nigerian children receiving antiretroviral treatment who are co-infected with tuberculosis

INTRODUCTION

Nigeria has a high burden of children living with HIV and tuberculosis (TB). This article examines the magnitude of TB among children receiving antiretroviral treatment (ART), compares their ART outcomes with their non-TB counterparts and argues that addressing TB among children on ART is critical for achieving the 90-90-90 targets.

METHODS

This was a facility-based, retrospective analysis of medical records of children aged <15 years who were newly initiated on ART between 2011 and 2012. Structured tools were used to collect data. STATA software was used to perform descriptive, survival and multivariate analyses.

RESULTS

A total of 1142 children with a median age of 3.5 years from 20 selected facilities were followed for 24 months. Of these, 95.8% were assessed for TB at ART initiation and 14.7% had TB. Children on ART were more likely to have TB if they were aged 5 years or older (p<0.01) and had delayed ART initiation (p<0.05). The cotrimoxazole and isoniazid prophylaxes were provided to 87.9 and 0.8% of children, respectively. The rate of new TB cases was 3 (2.2-4.0) per 100 person-years at six months and declined to 0.2 (0.06-1.4) per 100 person-years at 24 months. TB infection [adjusted hazard ratio (aHR): 4.3; 2.3-7.9], malnutrition (aHR: 5.1; 2.6-9.8), delayed ART initiation (aHR: 3.2; 1.5-6.7) and age less than 1 year at ART initiation (aHR: 4.0; 1.4-12.0) were associated with death. Additionally, patients with TB (aHR: 1.3; 1.1-1.6) and children below the age of 1 at ART initiation (aHR: 2.9; 1.7-5.2) were more likely to be lost to follow-up (LFU).

CONCLUSIONS

Children on ART with TB are less likely to survive and more likely to be LFU. These risks, along with low isoniazid uptake and delayed ART initiation, present a serious challenge to achieving the 90-90-90 targets and underscore an urgent need for inclusion of childhood TB/HIV in global plans and reporting mechanisms.

Incidence and Predictors of Tuberculosis among HIV Positive Children at University of Gondar Referral Hospital, Northwest Ethiopia: A Retrospective Follow-Up Study

Background. The aim of this study was to determine the incidence of tuberculosis and its predictors among HIV positive children. Methods. A six-year retrospective follow-up study was conducted among HIV infected children aged less than 15 years. Life table was used to estimate the cumulative probability of tuberculosis free survival. Cox proportional hazards model was used to identify predictors of tuberculosis. Results. A total of 271 HIV positive children were followed for six years and produced 1100.50 person-years of observation. During the follow-up period 52 new TB cases occurred. The overall incidence density of TB was 4.9 per 100 PY. Inappropriate vaccination [AHR: 8.03 (95% CI; 4.61–13.97)], ambulatory functional status [AHR: 1.99 (95% CI; 1.04–3.81)], and having baseline anemia [AHR: 2.23 (95% CI; 1.19–4.15)] were important predictors of time to TB occurrence. Conclusion. TB incidence rate was high. Early diagnosis and treatment of anemia and strengthening immunization program would reduce the risk of TB occurrence.

Severe acute malnutrition and infection

Severe acute malnutrition (SAM) is associated with increased severity of common infectious diseases, and death amongst children with SAM is almost always as a result of infection. The diagnosis and management of infection are often different in malnourished versus well-nourished children. The objectives of this brief are to outline the evidence underpinning important practical questions relating to the management of infectious diseases in children with SAM and to highlight research gaps. Overall, the evidence base for many aspects covered in this brief is very poor. The brief addresses antimicrobials; antipyretics; tuberculosis; HIV; malaria; pneumonia; diarrhoea; sepsis; measles; urinary tract infection; nosocomial Infections; soil transmitted helminths; skin infections and pharmacology in the context of SAM. The brief is structured into sets of clinical questions, which we hope will maximise the relevance to contemporary practice.

Impact of expanded antiretroviral use on incidence and prevalence of tuberculosis in children with HIV in Kenya

SETTING

Antiretroviral therapy (ART) reduces pulmonary tuberculosis (PTB) in human immunodeficiency virus (HIV) infected children. Recent ART recommendations have increased the number of children on ART.

OBJECTIVE

To determine the prevalence and incidence of TB in HIV-infected children after the implementation of expanded ART guidelines.

DESIGN

A prospective cohort study including HIV-infected children aged 6 weeks to 14 years was conducted in Kenya. The primary outcome measure was clinically diagnosed TB. Study participants were screened for prevalent TB at enrollment using Kenya's national guidelines and followed at monthly intervals to detect incident TB. Predictors of TB were assessed using logistic regression and Cox proportional hazards regression.

RESULTS

Of 689 participants (median age 6.4 years), 509 (73.9%) were on ART at baseline. There were 51 cases of prevalent TB (7.4%) and 10 incident cases, with over 720.3 child-years of observation (incidence 1.4 per 100 child-years). Months on ART (adjusted hazard ratio [aHR] 0.91, P = 0.003; aOR 0.91, P< 0.001) and months in care before ART (aHR 0.87, P= 0.001; aOR 0.92, P < 0.001) were protective against incident and prevalent TB.

CONCLUSIONS

ART was protective against TB in this cohort of HIV-infected children with high levels of ART use. Optimal TB prevention strategies should emphasize early ART in children.

Diagnosis of childhood tuberculosis and host RNA expression in Africa

BACKGROUND

Improved diagnostic tests for tuberculosis in children are needed. We hypothesized that transcriptional signatures of host blood could be used to distinguish tuberculosis from other diseases in African children who either were or were not infected with the human immunodeficiency virus (HIV).

METHODS

The study population comprised prospective cohorts of children who were undergoing evaluation for suspected tuberculosis in South Africa (655 children), Malawi (701 children), and Kenya (1599 children). Patients were assigned to groups according to whether the diagnosis was culture-confirmed tuberculosis, culture-negative tuberculosis, diseases other than tuberculosis, or latent tuberculosis infection. Diagnostic signatures distinguishing tuberculosis from other diseases and from latent tuberculosis infection were identified from genomewide analysis of RNA expression in host blood.

RESULTS

We identified a 51-transcript signature distinguishing tuberculosis from other diseases in the South African and Malawian children (the discovery cohort). In the Kenyan children (the validation cohort), a risk score based on the signature for tuberculosis and for diseases other than tuberculosis showed a sensitivity of 82.9% (95% confidence interval [CI], 68.6 to 94.3) and a specificity of 83.6% (95% CI, 74.6 to 92.7) for the diagnosis of culture-confirmed tuberculosis. Among patients with cultures negative for Mycobacterium tuberculosis who were treated for tuberculosis (those with highly probable, probable, or possible cases of tuberculosis), the estimated sensitivity was 62.5 to 82.3%, 42.1 to 80.8%, and 35.3 to 79.6%, respectively, for different estimates of actual tuberculosis in the groups. In comparison, the sensitivity of the Xpert MTB/RIF assay for molecular detection of M. tuberculosis DNA in cases of culture-confirmed tuberculosis was 54.3% (95% CI, 37.1 to 68.6), and the sensitivity in highly probable, probable, or possible cases was an estimated 25.0 to 35.7%, 5.3 to 13.3%, and 0%, respectively; the specificity of the assay was 100%.

CONCLUSIONS

RNA expression signatures provided data that helped distinguish tuberculosis from other diseases in African children with and those without HIV infection. (Funded by the European Union Action for Diseases of Poverty Program and others).

miRNA signatures in sera of patients with active pulmonary tuberculosis

Several studies showed that assessing levels of specific circulating microRNAs (miRNAs) is a non-invasive, rapid, and accurate method for diagnosing diseases or detecting alterations in physiological conditions. We aimed to identify a serum miRNA signature to be used for the diagnosis of tuberculosis (TB). To account for variations due to the genetic makeup, we enrolled adults from two study settings in Europe and Africa. The following categories of subjects were considered: healthy (H), active pulmonary TB (PTB), active pulmonary TB, HIV co-infected (PTB/HIV), latent TB infection (LTBI), other pulmonary infections (OPI), and active extra-pulmonary TB (EPTB). Sera from 10 subjects of the same category were pooled and, after total RNA extraction, screened for miRNA levels by TaqMan low-density arrays. After identification of “relevant miRNAs”, we refined the serum miRNA signature discriminating between H and PTB on individual subjects. Signatures were analyzed for their diagnostic performances using a multivariate logistic model and a Relevance Vector Machine (RVM) model. A leave-one-out-cross-validation (LOOCV) approach was adopted for assessing how both models could perform in practice. The analysis on pooled specimens identified selected miRNAs as discriminatory for the categories analyzed. On individual serum samples, we showed that 15 miRNAs serve as signature for H and PTB categories with a diagnostic accuracy of 82% (CI 70.2–90.0), and 77% (CI 64.2–85.9) in a RVM and a logistic classification model, respectively. Considering the different ethnicity, by selecting the specific signature for the European group (10 miRNAs) the diagnostic accuracy increased up to 83% (CI 68.1–92.1), and 81% (65.0–90.3), respectively. The African-specific signature (12 miRNAs) increased the diagnostic accuracy up to 95% (CI 76.4–99.1), and 100% (83.9–100.0), respectively. Serum miRNA signatures represent an interesting source of biomarkers for TB disease with the potential to discriminate between PTB and LTBI, but also among the other categories.