Lipoarabinomannan Antigen Assay (TB-LAM) for Diagnosing Pulmonary Tuberculosis in Children with Severe Acute Malnutrition in Mozambique

The Spectrum of Pathogens Associated with Infections in African Children with Severe Acute Malnutrition: A Scoping Review

Understanding the interplay between infections and severe acute malnutrition is critical in attaining good clinical outcomes when managing malnourished children. However, review studies describing the profile of the associated pathogens in the malnourished African paediatric population are sparse in the literature. We aimed to identify the spectrum of pathogens from studies reporting infections in severely malnourished African children, as well as the antibiotic resistance pattern and clinical outcomes. A systematic literature review of the PubMed database was conducted following PRISMA guidelines from January 2001 to June 2024. The search algorithm was ((marasmus) OR (kwashiorkor) OR (severe acute malnutrition) OR (protein energy malnutrition)) AND (Africa). For a more comprehensive retrieval, an additional search algorithm was deployed: ((HIV) OR (tuberculosis)) AND (severe acute malnutrition). We included 60 studies conducted between 2001 and 2024. Most of the studies were from East Africa (n = 45, 75%) and Southern Africa (n = 5, 8.3%). A total of 5845 pathogens were identified comprising 2007 viruses, 2275 bacteria, 1444 parasites, and 119 fungal pathogens. The predominant pathogens were HIV, Mycobacterium tuberculosis, and malaria parasites accounting for 33.8%, 30%, and 24.2% of pathogens identified. Antibiotic susceptibility testing was documented in only three studies. Fatality rates were reported in 45 studies and ranged from 2% to 56% regardless of the category of pathogen. This review affirms the deleterious effect of infections in malnourished patients and suggests a gross underdiagnosis as studies were found from only 17 (31.5%) African countries. Moreover, data on fungal infections in severely malnourished African children were nearly absent despite this population being at risk. Thus, there is an urgent need to prioritize research investigating African children with severe acute malnutrition for fungal infections besides other pathogens and improve the availability of diagnostic tools and the optimized usage of antibiotics through the implementation of antimicrobial stewardship programmes.

Pulmonary Tuberculosis in Severely Malnourished Children Admitted to Nutrition Rehabilitation Centers: A Multicenter Study

OBJECTIVES

To identify prevalence of pulmonary tuberculosis (TB) in severely malnourished children admitted to nutritional rehabilitation centers.

METHODS

A multicenter cross-sectional study involving 41 nutrition rehabilitation centres (NRCs) across India was carried out to document prevalence of pulmonary tuberculosis in acute severe malnourished children admitted in NRCs. After training of the NRC staff to follow algorithm provided by national tuberculosis elimination program, children admitted to NRCs were screened for pulmonary tuberculosis.

RESULTS

A total of 4356 children were enrolled across all the sites. Gastric aspirate for Cartridge based nucleic acid amplification test (CBNAAT), tuberculin skin test (TST) and X-ray film of chest were done in more than 99% of enrolled subjects. A total of 189 children (4.3%) had pulmonary tuberculosis. Eighty-seven (1.99%) were microbiologically confirmed by positive CBNAAT. On multivariate analysis, only significant association was with history of contact with TB patient in family.

CONCLUSIONS

The present results suggest that a significant proportion (>4%) of children admitted in NRCs suffer from pulmonary tuberculosis. It is feasible to improve diagnosis of tuberculosis as a whole and microbiologically confirmed TB.

Development of tuberculosis treatment decision algorithms in children below 5 years hospitalised with severe acute malnutrition in Zambia and Uganda: a prospective diagnostic cohort study

Background

In children with severe acute malnutrition (SAM) tuberculosis is common, challenging to diagnose, and often fatal. We developed tuberculosis treatment decision algorithms (TDAs) for children under the age of 5 years with SAM.

Methods

In this prospective diagnostic study, we enrolled and followed up children aged <60 months hospitalised with SAM at three tertiary hospitals in Zambia and Uganda from 4 November 2019 to 20 June 2022. We included children aged 2-59 months with SAM as defined by WHO and hospitalised following the WHO clinical criteria. We excluded children with current or history of antituberculosis treatment within the preceding 3 months. They underwent tuberculosis symptom screening, clinical assessment, chest X-ray, abdominal ultrasound, Xpert MTB/RIF Ultra (Ultra) and culture on respiratory and stool samples with 6 months follow-up. Tuberculosis was retrospectively defined using the 2015 standard case definition for childhood tuberculosis. We used logistic regression to develop diagnostic prediction models for a one-step diagnosis and a two-step screening and diagnostic approaches. We derived scores from models using WHO-recommended thresholds for sensitivity and proposed TDAs. This study is registered with ClinicalTrials.gov, NCT04240990.

Findings

Of 1906 children hospitalised with SAM during the study period, 1230 were screened, 1152 were eligible and 603 were enrolled. Of the 603 children enrolled-median age 15 (inter-quartile range (IQR): 11-20) months and 65 (11.0%) living with HIV-114 (18.9%) were diagnosed with tuberculosis, including 51 (8.5%) with microbiological confirmation and 104 (17.2%) initiated treatment at a median of 6(IQR: 2-10) days after inclusion. 108 children were retrospectively classified as having tuberculosis resulting in a prevalence of 17.9% (95% confidence intervals (CI): 15.1; 21.2). 75 (69.4%) children with tuberculosis reported cough of any duration, 32 (29.6%) cough ≥2 weeks and 11 (10.2%) tuberculosis contact history. 535 children had complete data and were included in the diagnostic prediction model. The one-step diagnostic model had 15 predictors, including Ultra, clinical, radiographic, and abdominal features, an area under the receiving operating curve (AUROC) of 0.910, and derived TDA sensitivity of 86.14% (95% CI: 78.07-91.56) and specificity of 80.88% (95% CI: 76.91-84.30). The two-step model had AUROCs of 0.750 and 0.912 for screening and diagnosis, respectively, and derived combined TDA sensitivity of 79.21% (95% CI: 70.30-85.98) and a specificity of 83.64% (95% CI: 79.87-86.82).

Interpretation

Tuberculosis prevalence was high among hospitalised children with SAM, with atypical clinical features. TDAs achieved satisfactory diagnostic accuracy and could be used to improve diagnosis in this vulnerable group.

Funding

Unitaid.

Accuracy of upper respiratory tract samples to diagnose Mycobacterium tuberculosis: a systematic review and meta-analysis

BACKGROUND

Pulmonary tuberculosis due to Mycobacterium tuberculosis can be challenging to diagnose when sputum samples cannot be obtained, which is especially problematic in children and older people. We systematically appraised the performance characteristics and diagnostic accuracy of upper respiratory tract sampling for diagnosing active pulmonary tuberculosis.

METHODS

In this systematic review and meta-analysis, we searched MEDLINE, Cinahl, Web of Science, Global Health, and Global Health Archive databases for studies published between database inception and Dec 6, 2022 that reported on the accuracy of upper respiratory tract sampling for tuberculosis diagnosis compared with microbiological testing of sputum or gastric aspirate reference standard. We included studies that evaluated the accuracy of upper respiratory tract sampling (laryngeal swabs, nasopharyngeal aspirate, oral swabs, saliva, mouth wash, nasal swabs, plaque samples, and nasopharyngeal swabs) to be tested for microbiological diagnosis of tuberculous (by culture and nucleic acid amplification tests) compared with a reference standard using either sputum or gastric lavage for a microbiological test. We included cohort, case-control, cross-sectional, and randomised controlled studies that recruited participants from any community or clinical setting. We excluded post-mortem studies. We used a random-effects meta-analysis with a bivariate hierarchical model to estimate pooled sensitivity, specificity, and diagnostics odds ratio (DOR; odds of a positive test with disease relative to without), stratified by sampling method. We assessed bias using QUADAS-2 criteria. This study is registered with PROSPERO (CRD42021262392).

FINDINGS

We screened 10 159 titles for inclusion, reviewed 274 full texts, and included 71, comprising 119 test comparisons published between May 13, 1933, and Dec 19, 2022, in the systematic review (53 in the meta-analysis). For laryngeal swabs, pooled sensitivity was 57·8% (95% CI 50·5-65·0), specificity was 93·8% (88·4-96·8), and DOR was 20·7 (11·1-38·8). Nasopharyngeal aspirate sensitivity was 65·2% (52·0-76·4), specificity was 97·9% (96·0-99·0), and DOR was 91·0 (37·8-218·8). Oral swabs sensitivity was 56·7% (44·3-68·2), specificity was 91·3% (CI 81·0-96·3), and DOR was 13·8 (5·6-34·0). Substantial heterogeneity in diagnostic accuracy was found, probably due to differences in reference and index standards.

INTERPRETATION

Upper respiratory tract sampling holds promise to expand access to tuberculosis diagnosis. Exploring historical methods using modern microbiological techniques might further increase options for alternative sample types. Prospective studies are needed to optimise accuracy and utility of sampling methods in clinical practice.

FUNDING

UK Medical Research Council, Wellcome, and UK Foreign, Commonwealth and Development Office.

Growth and anemia among children with tuberculosis infection at different sites in Southwest China

Objectives

To explore the effects of tuberculosis (TB) infection at different sites on anthropometric indicators, malnutrition and anemia incidence in children in Southwest China.

Methods

From January 2012 to December 2021, a total of 368 children aged 1 month to 16 years were enrolled. According to the sites of TB infection, they were divided into three groups: tuberculous meningitis (T group), tuberculous meningitis complicated withpulmonary tuberculosis (TP group), and tuberculous meningitis complicated with pulmonary tuberculosis and abdominal tuberculosis (TPA group). Data on weight, height, nutritional risk, blood biochemical indicators and basic descriptions were collected within 48 h after admission.

Results

The body mass index-for-age z score (BAZ), height-for-age z score (HAZ), and concentrations of hemoglobin (Hb) and albumin (ALB) decreased in the following order: T group, TP group, and TPA group. The prevalence of malnutrition was the highest in the TPA group (69.5%, 82/118) and 10-to 16-year-old group (72.4%, 63/87). Children aged 0.5-2 years exhibited the highest anemia prevalence of 70.6% (48/68) among the four age groups.The TPA group had the highest incidence of anemia (70.5%, 67/95) compared to T group and TP group.Compared with the treatment group, the abandonment group had a lower BAZ, HAZ and levels of HB and ALB, a higher rate of severe malnutrition, and higher nutritional risk scores. Children who had a low BAZ [odds ratio (OR) = 1.98], nutritional risk (OR = 0.56) and anemia (OR = 1.02) were less likely to obtain treatment with their guardians' support.

Conclusions

Children with tuberculous meningitis were at risk for growth disorders and anemia, especially when complicated with pulmonary tuberculosis and abdominal tuberculosis. The prevalence of anemia and malnutrition was the highest among patients aged 1 month to 2 years and 10-16 years, respectively. Nutritional status was one of the causes of abandoning treatment.

Review of Pediatric Tuberculosis in the Aftermath of COVID-19

In 2014, the World Health Organization developed the End Tuberculosis Strategy with the goal of a 95% reduction in deaths from tuberculosis (TB) by 2035. The start of the COVID-19 pandemic and global lockdown has had a major impact on TB awareness, screening, diagnosis, and prompt initiation of treatment, inevitably leading to a significant setback. We explore pediatric tuberculosis through the lens of the COVID-19 era, investigating how COVID-19 has impacted pediatric TB cases in different regions of the world and what the implications are for management moving forward to mitigate these effects. Furthermore, in light of recent findings showing how exposed infants and children are at higher risk than we thought of contracting the disease, greater attention and resources are needed to prevent further downward trends.

Diagnostic Advances in Childhood Tuberculosis—Improving Specimen Collection and Yield of Microbiological Diagnosis for Intrathoracic Tuberculosis

There is no microbiological gold standard for childhood tuberculosis (TB) diagnosis. The paucibacillary nature of the disease, challenges in sample collection in young children, and the limitations of currently available microbiological tests restrict microbiological confirmation of intrathoracic TB to the minority of children. Recent WHO guidelines recommend the use of novel rapid molecular assays as initial diagnostic tests for TB and endorse alternative sample collection methods for children. However, the uptake of these tools in high-endemic settings remains low. In this review, we appraise historic and new microbiological tests and sample collection techniques that can be used for the diagnosis of intrathoracic TB in children. We explore challenges and possible ways to improve diagnostic yield despite limitations, and identify research gaps to address in order to improve the microbiological diagnosis of intrathoracic TB in children.

Tuberculosis in children with severe acute malnutrition

INTRODUCTION

With growing attention globally to the childhood tuberculosis epidemic after decades of neglect, and with the burden of severe acute malnutrition (SAM) remaining unacceptably high worldwide, the collision of these two diseases is an important focus for improving child health.

AREAS COVERED

This review describes the clinical and public health implications of the interplay between tuberculosis and SAM, particularly for children under the age of five, and identifies priority areas for improved programmatic implementation and future research. We reviewed the literature on PubMed and other evidence known to the authors published until August 2021 relevant to this topic.

EXPERT OPINION

To achieve the World Health Organization's goal of eliminating deaths from childhood tuberculosis and to improve the abysmal outcomes for children with SAM, further research is needed to 1) better understand the epidemiologic connections between child tuberculosis and SAM, 2) improve case finding of tuberculosis in children with SAM, 3) assess unique treatment considerations for tuberculosis when children also have SAM, and 4) ensure tuberculosis and SAM are strongly addressed in decentralized, integrated models of providing primary healthcare to children.

Potential value of urine lateral-flow lipoarabinomannan (LAM) test for diagnosing tuberculosis among severely acute malnourished children

BACKGROUND

Tuberculosis (TB) is a serious co-morbidity among children with severe acute malnutrition (SAM) and TB diagnosis remains particularly challenging in the very young. We explored whether, in a low HIV-prevalence setting, the detection of mycobacterial lipoarabinomannan (LAM) antigen in urine may assist TB diagnosis in SAM children, a pediatric population currently not included in LAM-testing recommendations. To that end, we assessed LAM test-positivity among SAM children with and without signs or symptoms of TB.

METHODS

A cross-sectional assessment (February 2016-August 2017) included children <5 years with SAM from an Intensive-Therapeutic-Feeding-Centre in Madaoua, Niger. Group 1: children with signs or symptoms suggestive of TB. Group 2: children without any sign or symptom of TB. Urine-specimens were subjected to DetermineTM TB-LAM lateral-flow-test (using a 4-grade intensity scale for positives). LAM-results were used for study purposes and not for patient management. Programmatic TB-diagnosis was primarily based on patients' clinical symptoms and TB contact history with no systematic access to X-ray or microbiological reference testing.

RESULTS

102 (Group 1) and 100 children (Group 2) were included (median age 18 months, 59.4% male, 1.0% HIV-positive). In Group 1, 22 (21.6%) children were started on TB-treatment (probable TB) and none of the children in Group 2. LAM-positivity was 52.0% (53/102) and 37.0% (37/100) in Group 1 and 2, respectively. Low-intensity (Grade 1) LAM test-positivity was similarly high in both Groups (37.3% and 36.0%, respectively), while Grade 2 or 3-positives were mainly detected in Group 1 (Group 1: 14.7%, Group 2: 1.0%, p<0.001). When considering only Grades >1 as positive, LAM-testing detected 22.7% (95%CI: 7.8, 45.4) among probable TB cases, while 99% (95%CI: 94.6, 99.9) of unlikely TB cases (Group 2) tested negative.

CONCLUSION

These findings suggest the potential utility of LAM urine testing in HIV-negative children with SAM. Determine LAM-positivity with Grades >1 may identify HIV-negative SAM children that are eligible for rapid TB-treatment initiation, though low-intensity (Grade 1) LAM-positive results may not be helpful in this way. Further studies in this specific pediatric population are warranted, including evaluations of new generation LAM tests.