Role of Molecular Biomarkers in the Diagnosis of Invasive Fungal Diseases in Children

Insights into invasive fungal infection diagnostic and treatment capacities in tertiary care centres of Germany

Introduction

In Germany, the growing incidence of invasive fungal infections (IFIs) is a significant health concern, particularly impacting individuals with compromised immune systems due to factors like increasing transplant recipients, an ageing population, and heightened use of immunosuppressive medications. Diagnosing IFI remains challenging, and the integration of biomarker assays into clinical practice is difficult. Antifungal resistance, exemplified by pan-antifungal-resistant Candida auris cases, adds complexity to treatment. This study aims to provide a concise overview of the diagnostic and treatment landscape for IFI in Germany, identifying areas for improvement and paving the way for targeted interventions.

Methods

Data were collected using an online electronic case report form from October 2021 to February 2023. The survey included questions about institutional practices related to fungal infection diagnosis and treatment, with invitations extended to researchers nationwide.

Results

The study surveyed 58 hospitals across Germany. Notably, 77.6% managed high-risk patients for IFI. While 86% had onsite microbiology labs, a significant difference was noted for high-risk patients (93% in specialized hospitals versus 62% in others). Microscopy services had 96% coverage, while overall access to culture was 96%. Antigen tests had 96% coverage, and antibody access was reported at 98%. PCR testing was available at 98%. Imaging access showed no significant access differences. Variability existed in amphotericin B formulations based on patient profiles. Therapeutic drug monitoring was more common in high-risk patient institutions (89.5% versus 50.0%). All analysed institutions reported access to surgery (100%).

Conclusions

Addressing identified disparities in diagnostic and therapeutic resources for IFI is crucial to improving patient outcomes. The study calls for ongoing research and collaboration to optimize strategies for the prevention and treatment of IFI, emphasizing the importance of equitable access to resources, especially in high-risk patient populations.

A comprehensive assessment of the prolonged febrile neutropenia evaluation in pediatric oncology patients

BACKGROUND

Pediatric oncology patients with prolonged (≥96 hours) febrile neutropenia (absolute neutrophil count < 500/μL) often undergo an evaluation for invasive fungal disease (IFD) and other infections. Current literature suggests that beta-D-glucan (BDG), galactomannan, bronchoalveolar lavage (BAL), and computed tomography (CT) scans (sinus, chest, and abdomen/pelvis) may help determine a diagnosis in this population.

METHODS

In a retrospective cohort study of all cancer/stem cell transplant patients (diagnosed 2005-2019) from one pediatric hospital, all episodes with prolonged febrile neutropenia or IFD evaluations (defined as sending a fungal biomarker or performing a CT scan to assess for infection) were identified.

RESULTS

In total, 503 episodes met inclusion criteria and 64% underwent IFD evaluations. In total, 36.4% of episodes documented an infection after initiation of prolonged febrile evaluation, most commonly Clostridioides difficile colitis (6.4%) followed by a true bacterial bloodstream infection (BSI) (5.2%), proven/probable IFD (4.8%), and positive respiratory pathogen panel (3.6%). There was no difference in sinus CTs showing sinusitis (74% vs 63%, p = 0.46), whereas 32% of abdomen/pelvis CTs led to a non-IFD diagnosis, and 25% of chest CTs showed possible pneumonia. On chest CT, the positive predictive value (PPV) for IFD was 19% for nodules and 14% for tree and bud lesions. BDG had a PPV of 25% for IFD and GM 50%. BAL diagnosed IFD once and pneumocystis jirovecii pneumonia twice.

CONCLUSIONS

Chest CTs and abdomen/pelvis CTs provide clinically relevant information during the prolonged febrile neutropenia evaluation, whereas BDG, galactomannan, BAL, and sinus CTs have less certain utility.

How I approach: the transplant recipient with fever and pulmonary infiltrates

Recipients of hematopoietic stem cell transplants and solid organ transplants frequently develop pulmonary infiltrates from both infectious and non-infectious etiologies. Differentiation and further characterization of microbiologic etiologies-viral, bacterial, and fungal-can be exceedingly challenging. Pediatric patients face unique challenges as confirmatory evaluations with bronchoscopy or lung biopsy may be limited. A generalizable approach to diagnosing and managing these conditions has not been well established. This paper aims to summarize our initial clinical approach while discussing the relative evidence informing our practices. A pediatric patient with characteristic infiltrates who has undergone HSCT is presented to facilitate the discussion. Generalizable approaches to similar patients are highlighted as appropriate while highlighting considerations based on clinical course and key risk factors.

Diagnostic Utility of Galactomannan Enzyme Immunoassay in Invasive Aspergillosis in Pediatric patients with Hematological Malignancy

OBJECTIVE

This study aims to determine the diagnostic utility of galactomannan enzyme immunoassay (GM EIA) in invasive aspergillosis (IA) in children with hematological malignancy (high risk population) in terms of sensitivity, specificity, negative predictive value (NPV) and positive predictive values (PPV) at various cut offs while validating the revised EORTC/MSG 2019 criteria in order to obtain the best cut-off.

MATERIAL AND METHODS

For 100 pediatric patients, serum and respiratory samples were collected. Clinical, mycological workup (potassium-hydroxide mount, fungal culture) and GM EIA was done to classify proven, probable, and possible IA as per EORTC-MSG guidelines,2019. Sensitivity, specificity, PPV and NPV were calculated of GM indices at cut-off 0.5, 0.7 and 1, and validated with revised EORTC -MSG, 2019.

RESULTS

Of 100 patients enrolled, 75 were diagnosed with ALL, 14 with AML, two with Hodgkin's, three had non-Hodgkin lymphoma, and six had undifferentiated leukemia. With routine mycological findings, 51 were classified as probable IA, 11 as possible IA, and 38 as no IA. Aspergillus flavus was the most prevalent on culture (56.9%, 29/51) followed by A. fumigatus (29%, 15/51) A. niger (7.8%, 4/51), A. terreus (3.9%, 2/51) and A. nidulans (2%, 1/51). GM EIA demonstrated sensitivity 82.3%, specificity 97.4%, PPV 98.1%, and NPV 77.1% at cut-off 0.67 when comparing probable/possible IA v/s no IA groups. The GM EIA had the best sensitivity (82.4%), specificity (81.8%), PPV (95.5%), and NPV (50%) at cut off 0.78 when the probable IA group was compared to the possible IA. Seven patients succumbed of whom 5 had GMI ≥ 2.

CONCLUSION

This study deduces the optimal cut-off for serum GM EIA to be 0.67 obtained by ROC analysis when comparing possible and probable IA versus no IA and reinforces the definition of probable category of EORTC-MSG criteria, 2019. At 0.5 ODI the sensitivity (87.1%) and NPV (80.5%) are high, thus making it the most suitable cut-off for detecting true positive and ruling out IA respectively, in pediatric patients with hematological malignancy. GM EIA when performed adjunctive to clinico-radiological findings can prove to be screening, diagnostic and prognostic test for IA in pediatric hematological malignancy patients.

A pediatric case and literature review of mucormycosis: Diagnostic and treatment challenges in a resource poor setting

Mucormycosis is an emerging disease that primarily affects immunocompromised patients; however, it has also been reported in immunocompetent individuals. Studies in the pediatric population are limited and reported mostly in case studies or series. The aim of this case report is to present a pediatric mucormycosis originated from Sumatra Island, Indonesia. A 13-year-old boy was referred to a tertiary hospital with facial necrosis involving the nasal, oral, and left maxillary areas, as well as left periorbital edema. No known underlying conditions were documented. The diagnosis was confirmed by histopathological findings of broad, pauci-septate, ribbon-like hyphae branching at 90°. The patient was managed by a multidisciplinary team consisting of the ear, nose, and throat, infectious diseases, dermatology, surgery, microbiology, and pathology departments. Management of the patient included debridement of the necrotic lesion and antibiotics and anti-fungal (fluconazole). Due to unavailability, the patient was not treated with amphotericin B. The patient died after 30 days of admission. This case highlights the importance of maintaining a high suspicion of invasive mucormycosis, even in immunocompetent children, when symptoms and signs are present, especially in resource-limited settings.

The Challenge of Diagnosing Invasive Pulmonary Aspergillosis in Children: A Review of Existing and Emerging Tools

Invasive pulmonary aspergillosis remains a major cause of morbidity and mortality for immunocompromised children, particularly for patients with acute leukaemia and those undergoing haematopoietic stem cell transplantation. Timely diagnosis, using a combination of computed tomography (CT) imaging and microbiological testing, is key to improve prognosis, yet there are inherent challenges in this process. For CT imaging, changes in children are generally less specific than those reported in adults and recent data are limited. Respiratory sampling by either bronchoalveolar lavage or lung biopsy is recommended but is not always feasible in children, and serum biomarkers, including galactomannan, have important limitations. In this review we summarise the current paediatric data on available diagnostic tests for IPA and highlight key emerging diagnostic modalities with potential for future use.

Diagnosis and Management of Severe Water-Related Skin and Soft Tissue Sepsis: A Summative Review of the Literature

BACKGROUND

Skin and soft tissue infections (SSTIs) are common presentations in the emergency department. However, this is less common after contact with contaminated saltwater or freshwater. This review presents the diagnosis and management of water-related soft tissue sepsis in this vulnerable and difficult-to-treat subgroup of necrotizing soft tissue sepsis.

METHODS

A summative literature overview is presented regarding bacterial and fungal SSTI after contact with contaminated water, with practical diagnostic and management aspects.

RESULTS

The literature indicates that these wounds and infections remain difficult to treat. An approach using appropriate diagnostic tools with both medical and surgical management strategies is provided.

CONCLUSIONS

SSTIs due to water contamination of wounds involve unusual organisms with unusual resistance patterns, and require a nuanced and directed diagnostic approach with an adaptation of the usual antibiotic or antifungal selection to achieve a successful cure, along with aggressive debridement and wound care.

Epidemiology, Modern Diagnostics, and the Management of Mucorales Infections

Mucormycosis is an uncommon, yet deadly invasive fungal infection caused by the Mucorales moulds. These pathogens are a WHO-assigned high-priority pathogen group, as mucormycosis incidence is increasing, and there is unacceptably high mortality with current antifungal therapies. Current diagnostic methods have inadequate sensitivity and specificity and may have issues with accessibility or turnaround time. Patients with diabetes mellitus and immune compromise are predisposed to infection with these environmental fungi, but COVID-19 has established itself as a new risk factor. Mucorales also cause healthcare-associated outbreaks, and clusters associated with natural disasters have also been identified. Robust epidemiological surveillance into burden of disease, at-risk populations, and emerging pathogens is required. Emerging serological and molecular techniques may offer a faster route to diagnosis, while newly developed antifungal agents show promise in preliminary studies. Equitable access to these emerging diagnostic techniques and antifungal therapies will be key in identifying and treating mucormycosis, as delayed initiation of therapy is associated with higher mortality.

Consensus document on the management of febrile neutropenia in paediatric haematology and oncology patients of the Spanish Society of Pediatric Infectious Diseases (SEIP) and the Spanish Society of Pediatric Hematology and Oncology (SEHOP)

Febrile neutropenia is one of the main infectious complications experienced by paediatric patients with blood or solid tumours, which, despite the advances in diagnosis and treatment, are still associated with a significant morbidity and mortality. These patients have several risk factors for infection, chief of which are chemotherapy-induced neutropenia, the disruption of cutaneous and mucosal barriers and the use of intravascular devices. Early diagnosis and treatment of febrile neutropenia episodes based on the patient's characteristics is essential in patients with blood and solid tumours to improve their outcomes. Therefore, it is important to develop protocols in order to optimise and standardise its management. In addition, the rational use of antibiotics, with careful adjustment of the duration of treatment and antimicrobial spectrum, is crucial to address the increase in antimicrobial drug resistance. The aim of this document, developed jointly by the Spanish Society of Pediatric Infectious Diseases and the Spanish Society of Pediatric Hematology and Oncology, is to provide consensus recommendations for the management of febrile neutropenia in paediatric oncology and haematology patients, including the initial evaluation, the stepwise approach to its treatment, supportive care and invasive fungal infection, which each facility then needs to adapt to the characteristics of its patients and local epidemiological trends.

Changes in the epidemiology of invasive fungal disease in a Pediatric Hematology and Oncology Unit: the relevance of breakthrough infections

BACKGROUND

Invasive fungal disease (IFD) is a significant cause of morbimortality in children under chemotherapy or hematopoietic stem cell transplant (HSCT). The purpose of this study is to describe the changes in the IFD epidemiology that occurred in a Pediatric Hematology-Oncology Unit (PHOU) with an increasing activity over time.

METHODS

Retrospective revision of the medical records of children (from 6 months to 18 years old) diagnosed with IFD in the PHOU of a tertiary hospital in Madrid (Spain), between 2006 and 2019. IFD definitions were performed according to the EORTC revised criteria. Prevalence, epidemiological, diagnostic and therapeutic parameters were described. Comparative analyses were conducted using Chi-square, Mann-Whitney and Kruskal-Wallis tests, according to three time periods, the type of infection (yeast vs mold infections) and the outcome.

RESULTS

Twenty-eight episodes of IFD occurred in 27 out of 471 children at risk (50% males; median age of 9.8 years old, [IQR 4.9-15.1]), resulting in an overall global prevalence of 5.9%. Five episodes of candidemia and 23 bronchopulmonary mold diseases were registered. Six (21.4%), eight (28.6%) and 14 (50%) episodes met criteria for proven, probable and possible IFD, respectively. 71.4% of patients had a breakthrough infection, 28.6% required intensive care and 21.4% died during treatment. Over time, bronchopulmonary mold infections and breakthrough IFD increased (p=0.002 and p=0.012, respectively), occurring in children with more IFD host factors (p=0.028) and high-risk underlying disorders (p=0.012). A 64% increase in the number of admissions in the PHOU (p<0.001) and a 277% increase in the number of HSCT (p=0.008) were not followed by rising rates of mortality or IFD/1000 admissions (p=0.674).

CONCLUSIONS

In this study, we found that yeast infections decreased, while mold infections increased over time, being most of them breakthrough infections. These changes are probably related to the rising activity in our PHOU and an increase in the complexity of the baseline pathologies of patients. Fortunately, these facts were not followed by an increase in IFD prevalence or mortality rates.

Pediatric invasive fungal rhinosinusitis

Pediatric invasive fungal rhinosinusitis (PIFR) is a rapidly progressive, potentially fatal disease. Previous medical literature demonstrates that its early diagnosis significantly reduces the risk of mortality in these patients. This study aims to present an updated clinical algorithm for optimized diagnosis and management of PIFR. A comprehensive review was conducted with only original, full-text articles published in English and Spanish from Cochrane Library, Pub-Med/MEDLINE, Embase, Scopus, and Google Scholar between January 2010 and June 2022. Relevant information was extracted and then integrated to develop a clinical algorithm for a proper diagnosis and management of PIFR.

Updates in Laboratory Identification of Invasive Fungal Infection in Neonates

Invasive fungal infection (IFI) in immunocompromised neonates is significantly associated with high morbidity and mortality and has become the third most common infection in Neonatal Intensive Care Units. The early diagnosis of IFI for neonatal patients is difficult because of the lack of specific symptoms. The traditional blood culture remains the gold standard in clinical diagnosis for neonatal patients but it requires a long duration, which delays treatment initiation. Detections of fungal cell-wall components are developed for early diagnosis but the diagnostic accuracy in neonates needs to be improved. PCR-based laboratory methods, such as real-time PCR, droplet digital PCR, and the cationic conjugated polymer fluorescence resonance energy transfer (CCP-FRET) system, distinguish the infected fungal species by their specific nucleic acids and show a high sensitivity and specificity. Particularly, the CCP-FRET system, which contains a cationic conjugated polymer (CCP) fluorescent probe and pathogen-specific DNA labeled with fluorescent dyes, could identify multiple infections simultaneously. In the CCP-FRET system, the CCP and fungal DNA fragments can self-assemble into a complex with an electrostatic interaction and the CCP triggers the FRET effect under ultraviolet light to make the infection visible. Here, we summarize the recent laboratory methods for neonatal IFI identification and provide a new perspective for early clinical fungal diagnosis.

Prospective Evaluation of the Fungitell® (1→3) Beta-D-Glucan Assay as a Diagnostic Tool for Invasive Fungal Disease in Pediatric Allogeneic Hematopoietic Cell Transplantation: A Report from the Children's Oncology Group

BACKGROUND

Invasive fungal disease (IFD) is a major source of morbidity and mortality for hematopoietic cell transplant (HCT) recipients. Non-invasive biomarkers, such as the beta-D-glucan assay, may improve the diagnosis of IFD. The objective was to define the utility of surveillance testing using Fungitell® beta-D-glucan (BDG) assay in children receiving antifungal prophylaxis in the immediate post-HCT period.

METHODS

Weekly surveillance blood testing with the Fungitell® BDG assay was performed during the early post-HCT period in the context of a randomized trial of children, adolescents, and young adults undergoing allogeneic HCT allocated to triazole or caspofungin prophylaxis. Positivity was defined at the manufacturer cutoff of 80 pg/ml. IFD was adjudicated using blinded central reviewers. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for the Fungitell® BDG assay for the outcome of proven or probable IFD.

RESULTS

A total of 51 patients (out of 290 patients in the parent trial) contributed blood specimens. In total, 278 specimens were evaluated. Specificity was 80.8% (95% confidence interval [CI]: 75.6%-85.3%), and NPV was over 99% (95% CI: 86.8%-99.9%). However, there were no true positive results, resulting in sensitivity of 0% (95% CI: 0.0%-84.2%) and PPV of 0% (95% CI: 0.0%-6.7%).

CONCLUSIONS

Fungitell® BDG screening is of limited utility in diagnosing IFD in the post-HCT period, mainly due to high false-positive rates. Fungitell® BDG surveillance testing should not be performed in children during the early post-HCT period while receiving antifungal prophylaxis as the pretest probability for IFD is low.

Long-Term Kinetics of Serum Galactomannan during Treatment of Complicated Invasive Pulmonary Aspergillosis

Several studies have evaluated the serum galactomannan (GM) antigen assay in pediatric patients, and there is convincing evidence for its usefulness as a diagnostic tool for invasive Aspergillus infections in patients with acute leukemias or post allogeneic hematopoietic cell transplantation (HCT). Less is known about the utility of the assay in monitoring responses to treatment in patients with established invasive aspergillosis (IA). Here, we present the long-term kinetics of serum galactomannan in two severely immunocompromised adolescents with invasive pulmonary aspergillosis (IPA) who were cured after complicated clinical courses. We also review the utility of the GM antigen assay in serum as a prognostic tool around the time of diagnosis of IA and as a biomarker to monitor disease activity in patients with established IA and assess responses to systemic antifungal therapy.

Osteoarticular Mycoses

Osteoarticular mycoses are chronic debilitating infections that require extended courses of antifungal therapy and may warrant expert surgical intervention. As there has been no comprehensive review of these diseases, the International Consortium for Osteoarticular Mycoses prepared a definitive treatise for this important class of infections. Among the etiologies of osteoarticular mycoses are Candida spp., Aspergillus spp., Mucorales, dematiaceous fungi, non-Aspergillus hyaline molds, and endemic mycoses, including those caused by Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides species. This review analyzes the history, epidemiology, pathogenesis, clinical manifestations, diagnostic approaches, inflammatory biomarkers, diagnostic imaging modalities, treatments, and outcomes of osteomyelitis and septic arthritis caused by these organisms. Candida osteomyelitis and Candida arthritis are associated with greater events of hematogenous dissemination than those of most other osteoarticular mycoses. Traumatic inoculation is more commonly associated with osteoarticular mycoses caused by Aspergillus and non-Aspergillus molds. Synovial fluid cultures are highly sensitive in the detection of Candida and Aspergillus arthritis. Relapsed infection, particularly in Candida arthritis, may develop in relation to an inadequate duration of therapy. Overall mortality reflects survival from disseminated infection and underlying host factors.

Diagnosis by metagenomic next-generation sequencing of invasive pulmonary aspergillosis in an infant with chronic granulomatous disease

Invasive pulmonary aspergillosis (IPA) is a serious fungal infection, with a high degree of mortality in immunocompromised individuals. Diagnosis of IPA is challenging in that clinical manifestations are not specific, with sensitivity of traditional detection procedures low. We report a case of IPA in a chronic granulomatous disease (CGD) infant who was initially suspected to have a lung tumor. Aspergillus fumigatus was identified as the pathogen in bronchoalveolar lavage fluid (BALF) by next-generation sequencing (mNGS). The patient recovered rapidly following a change of appropriate antifungal treatment and was discharged. This case highlights the additional value of BALF-mNGS for the diagnosis of pediatric invasive pulmonary fungal infection in immune-deficient children.

Serum Beta-D-Glucan in the Diagnosis of Invasive Fungal Disease in Neonates, Children and Adolescents: A Critical Analysis of Current Data

β-D-glucan (BDG) is a cell wall component of many pathogenic fungi. The detection of BDG as an assay is clinically broadly used as a diagnostic tool. However, the current data on BDG in paediatrics are limited, prompting specific considerations about when BDG can be used in neonates and children. We aimed to analyse the available data for the use of serum BDG in neonates and immunocompromised children and adolescents; as well as to understand the extent and characteristics of the use of BDG in children in Europe.

Coexpression network analysis of human candida infection reveals key modules and hub genes responsible for host-pathogen interactions

Invasive fungal infections are a significant reason for morbidity and mortality among organ transplant recipients. Therefore, it is critical to investigate the host and candida niches to understand the epidemiology of fungal infections in transplantation. Candida albicans is an opportunistic fungal pathogen that causes fatal invasive mucosal infections, particularly in solid organ transplant patients. Therefore, identifying and characterizing these genes would play a vital role in understanding the complex regulation of host-pathogen interactions. Using 32 RNA-sequencing samples of human cells infected with C. albicans, we developed WGCNA coexpression networks and performed DESeq2 differential gene expression analysis to identify the genes that positively correlate with human candida infection. Using hierarchical clustering, we identified 5 distinct modules. We studied the inter- and intramodular gene network properties in the context of sample status traits and identified the highly enriched genes in the correlated modules. We identified 52 genes that were common in the most significant WGCNA turquoise module and differentially expressed genes in human endothelial cells (HUVEC) infection vs. control samples. As a validation step, we identified the differentially expressed genes from the independent Candida-infected human oral keratinocytes (OKF6) samples and validated 30 of the 52 common genes. We then performed the functional enrichment analysis using KEGG and GO. Finally, we performed protein-protein interaction (PPI) analysis using STRING and CytoHubba from 30 validated genes. We identified 8 hub genes (JUN, ATF3, VEGFA, SLC2A1, HK2, PTGS2, PFKFB3, and KLF6) that were enriched in response to hypoxia, angiogenesis, vasculogenesis, hypoxia-induced signaling, cancer, diabetes, and transplant-related disease pathways. The discovery of genes and functional pathways related to the immune system and gene coexpression and differential gene expression analyses may serve as novel diagnostic markers and potential therapeutic targets.

Pulmonary Aspergillosis Silently Presenting as Pneumothorax in Children with Leukemia: A Report of Three Cases

Aspergillosis causes invasive pulmonary disease in patients with hematological malignancies. Children with invasive pulmonary aspergillosis (IPA) usually have nonspecific radiographic findings unlike cavitary lesions commonly seen in adults. Pneumothorax due to rupture of peripheral fungal lesion may be a severe complication in patients with neutropenia. Here, we describe three children during induction chemotherapy for B-lymphoblastic leukemia with pneumothorax as a presenting feature of pulmonary aspergillosis.

Interpretation, pitfalls of biomarkers in diagnosis of invasive fungal diseases

BACKGROUND

Invasive Fungal Diseases (IFD), account for high morbidity and mortality in immunocompromised and seriously ill patients worldwide. Early, faster and accurate diagnosis with timely and appropriate patient management is critical for improved patient outcome and antifungal stewardship. Clinical/radiological presentations in IFD are non-specific and microscopy/culture based tests have low sensitivity and long turnaround time. Biomarkers have clinical utility for diagnosing IFD but their interpretation is not straight forward.

OBJECTIVES

This review discusses the salient characteristics, clinical usefulness and limitations of common biomarkers such as Galactomannan (GM), 1-3, β D glucan (βDG), mannan, anti-mannan antibody (Mn/antiMn), Cryptococcal antigen test (CrAg), Nucleic Acid Amplification (NAA) tests and next generation sequencing for diagnosing IFD.

CONTENTS

Fungal biomarkers are useful adjuncts as screening and diagnostic tools for IFD and are much more suited for 'ruling out' rather than 'ruling in' disease. GM, NAA tests are promising biomarkers for screening of invasive Aspergillosis in high risk asymptomatic patients who are not on antifungal therapy and for diagnosis of breakthrough infections in symptomatic patients. 1-3, β D glucan has limitations both as a 'rule in' and 'rule out' test and is useful in only specific clinical settings. Two consecutive positive 1-3-βDG tests or combined positivity with GM increases its specificity. Mn/antiMn, T2Candida nano diagnostic panel are promising candidates for diagnosing invasive candidiasis. Combining two or more biomarkers improves the sensitivity for prompt initiation of antifungal therapy and the negative predictive value for suspension of empirical treatment. Serum CrAg test is a good 'rule in' rather than a 'rule out' test in immunocompetent patients but has good diagnostic accuracy in immunocompromised patients. Detection of single nucleotide polymorphisms by next generation sequencing is useful for fungal characterization and identification of host determinants responsible for increased susceptibility to fungal infections but is still in experimental stages.

Mini Review: Risk Assessment, Clinical Manifestation, Prediction, and Prognosis of Mucormycosis: Implications for Pathogen- and Human-Derived Biomarkers

Mucormycosis is a fungal disease caused by members of the fungal order Mucorales, which are abundantly found in terrestrial environments. The fungi propagate clonally via mitospores, which are transmitted to humans through the air and cause superficial or invasive infections. The disease has emerged in recent years and coincides generally with immunosuppression on the patient side. Mucormycosis is still rarely recognized in the clinical because of its unspecific symptoms which often triggers misdiagnosis with bacterial or viral infections leading to prolonged therapeutic cycles and loss of valuable time to manage mucormycosis properly. Infected patients develop various clinical forms, most notably ranging from rhinocerebral via pulmonary to gastrointestinal forms. Traditional diagnosis is based on culture and histopathologic examinations of the affected tissue. But, the achievement of a precise result is time-consuming, labor-intensive, requires mycological expertise and the finding appears often too late. A rapid and precise diagnosis is mandatory because symptoms are non-specific and the disease is rapidly progressing with often fatal outcome. Mucormycosis was increasingly associated with other infections and underlying conditions and risk factors causing comorbidities, which are difficult to successfully manage. This mini-review summarizes the current knowledge on the epidemiology and causative agents of mucormycosis, transmission, risk factors, clinical presentation, diagnosis, and highlights the lack of appropriate biomarkers on the pathogen and the host sides for rapid pathogen and host susceptibility detection, respectively. Fungal antigens and single nucleotide polymorphisms (SNPs) in human host genes are useful for the assessment of susceptibility. This mini-review addresses possibilities for early prediction of susceptibility to mucormycosis based on forecasting of the risk of infection with fungal pathogens other than Mucorales. The topic of early prediction and diagnosis of mucormycosis represents a current research gap and highlights the importance of potential future developments in the area of risk assessment, susceptibility prognosis in conjunction with early diagnosis to reduce mortality in patients suffering from mucormycosis.

Consensus guidelines for antifungal prophylaxis in haematological malignancy and haemopoietic stem cell transplantation, 2021

Antifungal prophylaxis can reduce morbidity and mortality from invasive fungal disease (IFD). However, its use needs to be optimised and appropriately targeted to patients at highest risk to derive the most benefit. In addition to established risks for IFD, considerable recent progress in the treatment of malignancies has resulted in the development of new 'at-risk' groups. The changing epidemiology of IFD and emergence of drug resistance continue to impact choice of prophylaxis, highlighting the importance of active surveillance and knowledge of local epidemiology. These guidelines aim to highlight emerging risk groups and review the evidence and limitations around new formulations of established agents and new antifungal drugs. It provides recommendations around use and choice of antifungal prophylaxis, discusses the potential impact of the changing epidemiology of IFD and emergence of drug resistance, and future directions for risk stratification to assist optimal management of highly vulnerable patients.

Expression and Purification along with Evaluation of Serological Response and Diagnostic Potential of Recombinant Sap2 Protein from C. parapsilosis for Use in Systemic Candidiasis

Systemic candidiasis is the fourth most common bloodstream infection in ICU patients worldwide. Although C. albicans is a predominant species causing systemic candidiasis, infections caused by non-albicans Candida (NAC) species are increasingly becoming more prevalent globally along with the emergence of drug resistance. The diagnosis of systemic candidiasis is difficult due to the absence of significant clinical symptoms in patients. We investigated the diagnostic potential of recombinant secreted aspartyl proteinase 2 (rSap2) from C. parapsilosis for the detection of Candida infection. The rSap2 protein was successfully cloned, expressed and purified using Ni-NTA chromatography under denaturing conditions using an E. coli-based prokaryotic expression system, and refolded using a multi-step dialysis procedure. Structural analysis by CD and FTIR spectroscopy revealed the refolded protein to be in its near native conformation. Immunogenicity analysis demonstrated the rSap2 protein to be highly immunogenic as evident from significantly high titers of Sap2-specific antibodies in antigen immunized Balb/c mice, compared to sham-immunized controls. The diagnostic potential of rSap2 protein was evaluated using immunoblotting and ELISA assays using proven candidiasis patient serum and controls. Immunoblotting results indicate that reactivity to rSap2 was specific to candidiasis patient sera with no cross reactivity observed in healthy controls. Increased levels of anti-Sap2-specific Ig, IgG and IgM antibodies were observed in candidiasis patients compared to controls and was similar in sensitivity obtained when whole Candida was used as coating antigen. In summary, the rSap2 protein from C. parapsilosis has the potential to be used in the diagnosis of systemic candidiasis, providing a rapid, convenient, accurate and cost-effective strategy.

Neonatal invasive candidiasis: updates on clinical management and prevention

Neonatal invasive candidiasis is an important cause of morbidity and mortality in preterm infants. The incidence of invasive candidiasis in this population has been declining in high-income settings, largely due to preventive measures, although there are still considerable variations in incidence between health-care centres. Surveillance data and large, multicentre studies in lower-income settings are not available, although preventive measures in these settings have been shown to decrease the incidence of neonatal invasive candidiasis. Understanding risk factors and pathogenesis are key to the prevention of invasive candidiasis. The difficulty of a definitive diagnosis of invasive candidiasis and the high risk for death or substantial neurodevelopmental impairment, even with appropriate treatment, further increase the need for effective preventive measures. In this Review, we examine the pathogenesis, clinical presentation, and diagnosis of invasive candidiasis. We highlight commonly used and emerging preventive and prophylactic measures, including standardised central line care, antibiotic stewardship, antifungal prophylaxis, and probiotics. Finally, we provide updates on empirical treatment, clinical management in confirmed cases of invasive candidiasis, and antifungal pharmacotherapy.

Lessons from an Educational Invasive Fungal Disease Conference on Hospital Antifungal Stewardship Practices across the UK and Ireland

Invasive fungal disease (IFD) is a growing health burden. High mortality rates, increasing numbers of at-risk hosts, and a limited availability of rapid diagnostics and therapeutic options mean that patients are increasingly exposed to unnecessary antifungals. High rates of prescriptions promote patient exposure to undue toxicity and drive the emergence of resistance. Antifungal stewardship (AFS) aims to guide antifungal usage and reduce unnecessary exposure and antifungal consumption whilst maintaining or improving outcomes. Here, we examine several AFS approaches from hospitals across the UK and Ireland to demonstrate the benefits of AFS practices and support the broader implementation of AFS as both a necessary and achievable strategy. Since the accuracy and turnaround times (TATs) of diagnostic tools can impact treatment decisions, several AFS strategies have included the development and implementation of diagnostic-driven care pathways. AFS informed treatment strategies can help stratify patients on a risk basis ensuring the right patients receive antifungals at the optimal time. Using a multidisciplinary approach is also key due to the complexity of managing and treating patients at risk of IFD. Through knowledge sharing, such as The Gilead Antifungal Information Network (GAIN), we hope to drive practices that improve patient management and support the preservation of antifungals for future use.

Challenges with Utilizing the 1,3-Beta-d-Glucan and Galactomannan Assays To Diagnose Invasive Mold Infections in Immunocompromised Children

Establishing the diagnosis of invasive mold infections (IMI) in immunocompromised children is challenging due to nonspecific clinical presentations and the limited sensitivity of traditional culture-based methods. Rapid non-culture-based diagnostics such as the 1,3-beta-d-glucan and galactomannan assays have emerged as promising adjuncts to conventional diagnostic tests in adults. Available data suggest that 1,3-beta-d-glucan has limited accuracy in the pediatric population and is not recommended to be used for the diagnosis of IMI in children. On the other hand, the diagnostic performance of the serum and bronchoalveolar lavage galactomannan in immunocompromised children is comparable to results observed in adults and can be used as a screening tool in children at high risk of developing invasive aspergillosis (IA) who are not receiving mold-active antifungal prophylaxis and as a diagnostic tool in symptomatic children suspected of having IA. Herein, we summarize the available evidence for the use of these rapid non-culture-based diagnostics in immunocompromised children. We also summarize potential causes of false positivity for the 1,3-beta-d-glucan and galactomannan assays.

[Fungal infection in immunocompromised children]

In recent years, immunodeficiency condition has experienced a rise among children, who are at risk of invasive fungal infections (IFI) due to their health condition. Cancer, non-malignant hematological diseases, as primary immunodeficiencies, hematopoietic stem cell transplantation (HSCT), extreme prematurity, or critically ill condition in Pediatric Intensive Care Unit (PICU) are some immunosuppressive situations in children. The use of oncologic therapies, including immunotherapy and monoclonal antibodies, for the treatment of the aforementioned health conditions has led to an increase in morbidity and mortality rates of IFI in children. The underlying diseases and their management, comorbidities, the diagnostic tests used (both molecular and imaging), as well as the treatment used can be significantly different between adult patients and children admitted to PICU or with cancer. In pediatrics, the treatment of IFI is based primarily on pharmacokinetic studies performed in adults. In higher risk patients prophylaxis should be considered and, in the case of an IFI diagnosis, an antifungal treatment should be administered as early as possible, supported by the reversion of the immune dysfunction and surgery when appropriate.

Central Nervous System Mold Infections in Children with Hematological Malignancies: Advances in Diagnosis and Treatment

The incidence of invasive mold disease (IMD) has significantly increased over the last decades, and IMD of the central nervous system (CNS) is a particularly severe form of this infection. Solid data on the incidence of CNS IMD in the pediatric setting are lacking, in which Aspergillus spp. is the most prevalent pathogen, followed by mucorales. CNS IMD is difficult to diagnose, and although imaging tools such as magnetic resonance imaging have considerably improved, these techniques are still unspecific. As microscopy and culture have a low sensitivity, non-culture-based assays such as the detection of fungal antigens (e.g., galactomannan or beta-D-glucan) or the detection of fungal nucleic acids by molecular assays need to be validated in children with suspected CNS IMD. New and potent antifungal compounds helped to improve outcome of CNS IMD, but not all agents are approved for children and a pediatric dosage has not been established. Therefore, studies have to rapidly evaluate dosage, safety and efficacy of antifungal compounds in the pediatric setting. This review will summarize the current knowledge on diagnostic tools and on the management of CNS IMD with a focus on pediatric patients.

Serum (1 → 3)-β-D-glucan could be useful to rule out invasive candidiasis in neonates with an adapted cut-off

AIM

We assessed the diagnostic accuracy of serum (1 → 3)-β-D-glucan (BDG) for neonatal invasive candidiasis (NIC) using the recommended cut-off usually used in adults for detecting invasive candidiasis and searched for an optimal cut-off for ruling out NIC.

METHODS

We conducted a prospective cross-sectional study at Nantes University medical centre from January 2017 to July 2018. All consecutive newborn infants of less than 28 days of corrected age, with clinically suspected NIC, who underwent BDG assay, were included. Sensitivity and specificity were calculated by using the recommended cut-off of 80 pg/mL. Receiver operating characteristic curve analysis was used to identify an optimal cut-off value.

RESULTS

We included 55 newborn infants with 61 episodes of suspected NIC. Their median gestational and chronological ages were 28.0 weeks (interquartile range [IQR] 26.4-34.1) and 10.0 days (IQR 6.0-22.0), respectively. Of 61 episodes, seven revealed NIC. Sensitivity and specificity were 85.7% (95% confidence interval [CI] 42.1%-99.6%) and 51.9% (37.8%-65.7%) with the recommended cut-off, respectively. An optimal cut-off of 174 pg/mL offered the same sensitivity but higher specificity 77.8% (64.4%-88.0%).

CONCLUSION

The recommended cut-off of 80 pg/mL was probably too low for ruling out NIC. A higher cut-off might have been more appropriate.

Johnson E, Littlechild J, Winlove CP, Vollmer F, Gow NAR. Biosensors and Diagnostics for Fungal Detection

Early detection is critical to the successful treatment of life-threatening infections caused by fungal pathogens, as late diagnosis of systemic infection almost always equates with a poor prognosis. The field of fungal diagnostics has some tests that are relatively simple, rapid to perform and are potentially suitable at the point of care. However, there are also more complex high-technology methodologies that offer new opportunities regarding the scale and precision of fungal diagnosis, but may be more limited in their portability and affordability. Future developments in this field are increasingly incorporating new technologies provided by the use of new format biosensors. This overview provides a critical review of current fungal diagnostics and the development of new biophysical technologies that are being applied for selective new sensitive fungal biosensors to augment traditional diagnostic methodologies.

Revision and Update of the Consensus Definitions of Invasive Fungal Disease From the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium

BACKGROUND

Invasive fungal diseases (IFDs) remain important causes of morbidity and mortality. The consensus definitions of the Infectious Diseases Group of the European Organization for Research and Treatment of Cancer and the Mycoses Study Group have been of immense value to researchers who conduct clinical trials of antifungals, assess diagnostic tests, and undertake epidemiologic studies. However, their utility has not extended beyond patients with cancer or recipients of stem cell or solid organ transplants. With newer diagnostic techniques available, it was clear that an update of these definitions was essential.

METHODS

To achieve this, 10 working groups looked closely at imaging, laboratory diagnosis, and special populations at risk of IFD. A final version of the manuscript was agreed upon after the groups' findings were presented at a scientific symposium and after a 3-month period for public comment. There were several rounds of discussion before a final version of the manuscript was approved.

RESULTS

There is no change in the classifications of "proven," "probable," and "possible" IFD, although the definition of "probable" has been expanded and the scope of the category "possible" has been diminished. The category of proven IFD can apply to any patient, regardless of whether the patient is immunocompromised. The probable and possible categories are proposed for immunocompromised patients only, except for endemic mycoses.

CONCLUSIONS

These updated definitions of IFDs should prove applicable in clinical, diagnostic, and epidemiologic research of a broader range of patients at high-risk.

Pulmonary Metagenomic Sequencing Suggests Missed Infections in Immunocompromised Children

BACKGROUND

Despite improved diagnostics, pulmonary pathogens in immunocompromised children frequently evade detection, leading to significant mortality. Therefore, we aimed to develop a highly sensitive metagenomic next-generation sequencing (mNGS) assay capable of evaluating the pulmonary microbiome and identifying diverse pathogens in the lungs of immunocompromised children.

METHODS

We collected 41 lower respiratory specimens from 34 immunocompromised children undergoing evaluation for pulmonary disease at 3 children's hospitals from 2014-2016. Samples underwent mechanical homogenization, parallel RNA/DNA extraction, and metagenomic sequencing. Sequencing reads were aligned to the National Center for Biotechnology Information nucleotide reference database to determine taxonomic identities. Statistical outliers were determined based on abundance within each sample and relative to other samples in the cohort.

RESULTS

We identified a rich cross-domain pulmonary microbiome that contained bacteria, fungi, RNA viruses, and DNA viruses in each patient. Potentially pathogenic bacteria were ubiquitous among samples but could be distinguished as possible causes of disease by parsing for outlier organisms. Samples with bacterial outliers had significantly depressed alpha-diversity (median, 0.61; interquartile range [IQR], 0.33-0.72 vs median, 0.96; IQR, 0.94-0.96; P < .001). Potential pathogens were detected in half of samples previously negative by clinical diagnostics, demonstrating increased sensitivity for missed pulmonary pathogens (P < .001).

CONCLUSIONS

An optimized mNGS assay for pulmonary microbes demonstrates significant inoculation of the lower airways of immunocompromised children with diverse bacteria, fungi, and viruses. Potential pathogens can be identified based on absolute and relative abundance. Ongoing investigation is needed to determine the pathogenic significance of outlier microbes in the lungs of immunocompromised children with pulmonary disease.

Assessment of Serum Galactomannan Test Results of Pediatric Patients With Hematologic Malignancies According to Consecutive Positivity and Threshold Level in Terms of Invasive Aspergillosis Diagnosis: Cross-Sectional Research in a Tertiary Care Hospital

The aim of this study was to evaluate the diagnostic utility of serum galactomannan (GM) positivity for invasive aspergillosis (IA) in children. Positive GM results between January 2015 and August 2017 were reviewed retrospectively in children with hematologic malignancies. Single and consecutive positive GM results were evaluated according to the different galactomannan index (GMI) (>0.5, >0.7, >1.0 and >1.5) values. There were 104 positive GM results of 70 patients. IA was identified in 29 patients (41.4%) (2 proven and 27 probable). For a single positive GMI of >0.5, >0.7, >1.0, and >1.5, the numbers were 104, 76, 57, and 32 and the positive predictive values (PPVs) were 39.4%, 43.2%, 47.2%, and 50.0%, respectively. The single GM positivity at different thresholds showed no difference between the IA and non-IA group (P>0.05). For 2 consecutive positive GMI values of >0.5, >0.7, >1.0, and >1.5, the numbers were 34, 20, 13, and 4, and the PPVs were 58.8%, 65.0%, 84.6%, and 100.0%, respectively. In the IA group, positivity was higher at all thresholds (P<0.05). According to our findings, consecutive GM positivity has higher PPVs independently from the cutoff value chosen. In pediatric patients with high risk, consecutive sampling should be preferred.

Fungal infections in children with haematologic malignancies and stem cell transplant recipients

Children with haematologic malignancies and haematopoietic stem cell transplant recipients are at high risk for invasive fungal diseases (IFD). There has been an increased number of at-risk children over the past two decades due to improvements in cancer therapies resulting in improved survival of children with high-risk and refractory malignancies. The predominant organisms that cause IFD include Candida spp., Aspergillus spp. and the Mucorales molds. Clinical presentations of IFD vary based on host immune status and the causative organism. Though serum biomarkers such as the galactomannan assay and beta-D-glucan assay have been validated in adults, there are limited data regarding their diagnostic value in children. Thus, the gold standard for IFD diagnosis remains tissue biopsy with histopathological and microbiological evaluation. Treatment of IFD is multimodal and involves antifungal drugs, correction of immune dysfunction and surgical resection when feasible. Paediatric practice regarding IFD is largely extrapolated from data generated in adult patients; in this review, we evaluate both primary paediatric studies and guidelines intended for adult patients that are applied to paediatric patients. There remain significant knowledge gaps with respect to the prevention, diagnosis and treatment of IFD in immunocompromised children, and further research is needed to help guide management decisions.

Diagnostic value of Candida mannan antigen and anti-mannan IgG and IgM antibodies for Candida infection

OBJECTIVE

To assess the diagnostic value of serum Candida mannan antigen (MN) and anti-mannan IgG and IgM antibodies for candidiasis.

METHODS

This study was a prospective cohort study. Clinical data and venous blood samples from 23 medical centres in Beijing, China were collected between 1 January 2017 and 31 December 2018. All collected specimens were tested within one week for serum Candida MN and IgG and IgM antibodies using an ELISA kit.

RESULTS

A total of 452 patients were enrolled, including 188 patients in the Candida exposure groups (56 patients with Candida bloodstream infection, 69 patients with Candida-positive tracheal aspirate cultures and 63 patients with Candida-positive urine cultures) and 264 patients in the control groups (212 healthy controls and 52 patients with bacteraemia). The receiver operating characteristic (ROC) curve of the 56 patients with Candida bloodstream infection and 212 healthy controls showed that serum MN and IgG had good diagnostic value. The area under the ROC curve (AUC) values were 0.812 (95% CI, 0.750-0.873) and 0.866 (95% CI, 0.808-0.924), respectively, wherein the MN specificity and sensitivity were 86.79% and 60.71%, and the IgG were 84.43% and 80.36%, respectively. The AUC of the combination of serum MN and IgG was 0.871(95% CI, 0.813-0.929), and the specificity and sensitivity were 93.87% and 57.14%.

CONCLUSIONS

The serum levels of Candida MN and its IgG antibody have diagnostic value for Candida bloodstream infection, and combination of MN and IgG can improve diagnostic specificity and may provide a new approach for diagnosis of candidaemia.

Diagnosis of invasive fungal disease in children: a narrative review

Introduction: Invasive fungal diseases (IFD) represent important causes of morbidity and mortality in pediatrics. Early diagnosis and treatment of IFD is associated with better outcome and this entails the need to use fast and highly sensitive and specific methods that can support clinicians in the management of IFD.Areas covered: A narrative review was performed on conventional diagnostic methods such as culture, microscopy and histopathology are still gold standard but are burdened by a lack of sensitivity and specificity; on the other hand, imaging and noninvasive antigen-based such as beta-D-glucan, galactomannan and molecular biomarkers are the most convenient nonculture methods for diagnosis and monitoring effects of therapy. Aim of the present review is to summarize what is available in these fields at end of the second decade of the third millennium and look for future perspectives.Expert opinion: Promising and useful diagnostic methods have been applied in infectious disease diagnosis in clinical practice or in designing platforms. Unfortunately, most of them are not standardized or validated in pediatric population. However, clinicians should be aware of all innovative diagnostic tools to use in combination with conventional diagnostic methods for a better management of pathology and patient.

Recent advances in the prevention and management of infections in children undergoing treatment for cancer

A major consequence of the intensive multi-modal chemotherapy commonly used to treat malignancies in childhood is life-threatening infection, frequently during periods of profound neutropenia. Recent advances have been made in all areas of management, from trying to prevent infection to getting patients off antimicrobials and home again in the shortest, safest way. Potential avenues of further research are outlined for readers to be aware of in the next few years.

Surveillance study of the prevalence, species distribution, antifungal susceptibility, risk factors and mortality of invasive candidiasis in a tertiary teaching hospital in Southwest China

BACKGROUND

Invasive candidiasis (IC) is the most common invasive fungal infection. The epidemiology of IC in hospitalized patients has been widely investigated in many metropolitan cities; however, little information from medium and small cities is known.

METHODS

A 5-year retrospective study was carried out to analyze the prevalence, species distribution, antifungal susceptibility, risk factors and mortality of inpatients with invasive Candida infection in a regional tertiary teaching hospital in Southwest China.

RESULTS

A total of 243 inpatients with invasive Candida infection during the five-year study period were identified, with a mean annual incidence of 0.41 cases per 1000 admissions and a 30-day mortality rate of 12.3%. The species distributions of Candida albicans, Candida glabrata, Candida tropicalis, Candida krusei, Candida parapsilosis and other Candida species was 45.3, 30.0, 15.2, 4.9, 2.1 and 2.5%, respectively. The total resistance rates of fluconazole (FCA), itraconazole (ITR) and voriconazole (VRC) were 18.6, 23.1 and 18.5%, respectively. Respiratory dysfunction, pulmonary infection, cardiovascular disease, chronic/acute renal failure, mechanical ventilation, abdominal surgery, intensive care in adults, septic shock and IC due to C. albicans were associated with 30-day mortality (P < 0.05) according to the univariate analyses. Respiratory dysfunction [odds ratio (OR), 9.80; 95% confidence interval (CI), 3.24-29.63; P < 0.001] and IC due to C. albicans (OR, 3.35; 95% CI, 1.13-9.92; P = 0.029) were the independent predictors of 30-day mortality.

CONCLUSIONS

This report shows that the incidence and mortality rates are lower and that the resistance rates to azoles are higher in medium and small cities than in large cities and that the species distributions and risk factors in medium and small cities are different from those in large cities in China. It is necessary to conduct epidemiological surveillance in medium and small cities to provide reference data for the surveillance of inpatients with IC infections.

Pediatric Mucormycosis: A 10-Year Systematic Review of Reported Cases and Review of the Literature

Mucormycosis is a severe infection that affects a variety of patients, including immunocompromised children and neonates. Given improved survival rates from advances in the treatment of malignancies, the population at risk for mucormycosis is increasing. We conducted a systematic review of cases of mucormycosis in children in the English-language literature reported between August 2008 and June 2017 and analyzed the clinical characteristics, diagnosis, management, and outcome of those infections. The most common underlying diagnoses included neutropenia (41%), hematologic malignancy (39%), prematurity (13%), and hematopoietic stem cell transplant (11%). Sinus disease (28%) and disseminated disease (24%) were the most common presentations. Rhizopus spp were the most common organisms isolated (22%). Amphotericin B remains the backbone of treatment and was prescribed in 86% of these cases. The resulting mortality rate remains high (32%). We provide here the results of a literature review of mucormycosis in children, including its epidemiology and clinical manifestations, and describe current advances in its diagnosis and treatment.

Diagnostic accuracy of serum (1,3)-beta-d-glucan for neonatal invasive candidiasis: systematic review and meta-analysis

OBJECTIVES

Neonatal invasive candidiasis (NIC) is a leading cause of infection-related morbidity and mortality in preterm neonates. Several studies have shown that (1,3)-Beta-d-glucan (BDG) was accurate in detecting invasive fungal infection in adults, but studies in neonates are scarce. The aim was to obtain summary estimates of the accuracy of BDG detection in serum for the diagnosis of NIC.

METHODS

We searched Medline, Embase, Clinicaltrials.gov, and Google Scholar (inception to July 2019). We checked the reference lists of included studies, clinical guidelines, and review articles. We included studies that assessed the accuracy of BDG against a reference standard that defined groups of patients with ordinal levels of NIC probability (e.g. proven, probable, possible) and included fungal blood culture. Participants were neonates suspected of having NIC. The intervention was BDG measurement in serum (Fungitell® assay). We assessed risk of bias and applicability using QUADAS-2. We used bivariate meta-analysis to produce summary estimates of diagnostic accuracy at prespecified positivity thresholds of 80 and 120 pg/mL. This study was registered with PROSPERO (CRD42018089545).

RESULTS

We included eight studies (465 participants). Of these, two were judged at low overall risk of bias. There was substantial variability across studies in the reference standards used. At a positivity threshold of 80 pg/mL, summary estimates of sensitivity and specificity of BDG were 89% (95% CI: 80-94%) and 60% (53-66%), respectively; summary sensitivity for detecting proven cases of NIC was 99% (93-100%). At a positivity threshold of 120 pg/mL, summary estimates of sensitivity and specificity were 81% (71-88%) and 80% (67-88%), respectively.

CONCLUSIONS

Because of high sensitivity, BDG seems promising to rule-out NIC. It might be too early to recommend its use because of the scarcity of reliable clinical data, heterogeneity in case definitions, and unstable accuracy estimates.

Invasive Aspergillosis in Pediatric Leukemia Patients: Prevention and Treatment

The purpose of this article is to review and update the strategies for prevention and treatment of invasive aspergillosis (IA) in pediatric patients with leukemia and in patients with hematopoietic stem cell transplantation. The major risk factors associated with IA will be described since their recognition constitutes the first step of prevention. The latter is further analyzed into chemoprophylaxis and non-pharmacologic approaches. Triazoles are the mainstay of anti-fungal prophylaxis while the other measures revolve around reducing exposure to mold spores. Three levels of treatment have been identified: (a) empiric, (b) pre-emptive, and (c) targeted treatment. Empiric is initiated in febrile neutropenic patients and uses mainly caspofungin and liposomal amphotericin B (LAMB). Pre-emptive is a diagnostic driven approach attempting to reduce unnecessary use of anti-fungals. Treatment targeted at proven or probable IA is age-dependent, with voriconazole and LAMB being the cornerstones in >2yrs and <2yrs age groups, respectively.

Invasive Candidiasis in Infants and Children: Recent Advances in Epidemiology, Diagnosis, and Treatment

This paper reviews recent advances in three selected areas of pediatric invasive candidiasis: epidemiology, diagnosis, and treatment. Although the epidemiological trends of pediatric invasive candidiasis illustrate a declining incidence, this infection still carries a heavy burden of mortality and morbidity that warrants a high index of clinical suspicion, the need for rapid diagnostic systems, and the early initiation of antifungal therapy. The development of non-culture-based technologies, such as the T2Candida system and (1→3)-β-d-glucan detection assay, offers the potential for early laboratory detection of candidemia and CNS candidiasis, respectively. Among the complications of disseminated candidiasis in infants and children, hematogenous disseminated Candida meningoencephalitis (HCME) is an important cause of neurological morbidity. Detection of (1→3)-β-d-glucan in cerebrospinal fluid serves as an early diagnostic indicator and an important biomarker of therapeutic response. The recently reported pharmacokinetic data of liposomal amphotericin B in children demonstrate dose–exposure relationships similar to those in adults. The recently completed randomized clinical trial of micafungin versus deoxycholate amphotericin B in the treatment of neonatal candidemia provides further safety data for an echinocandin in this clinical setting.

Biomarker-guided antifungal stewardship policies for patients with invasive candidiasis

Invasive fungal infections (IFIs) are among the life-threatening issues in patients with impaired immune system. High administration of antifungals in these patients imposes a heavy economic burden on the national health system. In addition, despite the usually expensive antifungal regimens, the mortality rate due to fungal infections is still high, resulting in the loss of hundreds of lives per year. Survival rate is an indicator of the success of national healthcare policies. Early diagnosis of IFI is critical because any delays may be fatal. The weakness of the old-fashioned culture-based diagnostic methods lies in their time-consuming laboratory procedures. To overcome this problem, several diagnostic approaches have been developed to facilitate the early diagnosis of invasive candidiasis as the most prevalent IFI. These methods are based on the detection of serologic and molecular footprints. However, nowadays, antibiotic resistance and proper and cost-effective use of antibiotics are given special attention in national healthcare policies. The instructions for controlling these indices have been collected under the name of antibiotic stewardship. The present review study was targeted toward providing insight into novel diagnostic biomarkers and antifungal stewardship programs. The simultaneous investigation of these two issues facilitates the achievement of a novel health policy for the treatment of systemic candidiasis in immunocompromised patients.

Advances in the Treatment of Mycoses in Pediatric Patients

The main indications for antifungal drug administration in pediatrics are reviewed as well as an update of the data of antifungal agents and antifungal policies performed. Specifically, antifungal therapy in three main areas is updated as follows: a) Prophylaxis of premature neonates against invasive candidiasis; b) management of candidemia and meningoencephalitis in neonates; and c) prophylaxis, empiric therapy, and targeted antifungal therapy in children with primary or secondary immunodeficiencies. Fluconazole remains the most frequent antifungal prophylactic agent given to high-risk neonates and children. However, the emergence of fluconazole resistance, particularly in non-albicans Candida species, should be considered during preventive or empiric therapy. In very-low birth-weight neonates, although fluconazole is used as antifungal prophylaxis in neonatal intensive care units (NICU's) with relatively high incidence of invasive candidiasis (IC), its role is under continuous debate. Amphotericin B, primarily in its liposomal formulation, remains the mainstay of therapy for treating neonatal and pediatric yeast and mold infections. Voriconazole is indicated for mold infections except for mucormycosis in children >2 years. Newer triazoles-such as posaconazole and isavuconazole-as well as echinocandins, are either licensed or under study for first-line or salvage therapy, whereas combination therapy is kept for refractory cases.