Fungal Infections of the Central Nervous System in Children

Pediatric Meningeal Diseases: What Radiologists Need to Know

Evaluating altered mental status and suspected meningeal disorders in children often begins with imaging, typically before a lumbar puncture. The challenge is that meningeal enhancement is a common finding across a range of pathologies, making diagnosis complex. This review proposes a categorization of meningeal diseases based on their predominant imaging characteristics. It includes a detailed description of the clinical and imaging features of various conditions that lead to leptomeningeal or pachymeningeal enhancement in children and adolescents. These conditions encompass infectious meningitis (viral, bacterial, tuberculous, algal, and fungal), autoimmune diseases (such as anti-MOG demyelination, neurosarcoidosis, Guillain-Barré syndrome, idiopathic hypertrophic pachymeningitis, and NMDA-related encephalitis), primary and secondary tumors (including diffuse glioneuronal tumor of childhood, primary CNS rhabdomyosarcoma, primary CNS tumoral metastasis, extracranial tumor metastasis, and lymphoma), tumor-like diseases (Langerhans cell histiocytosis and ALK-positive histiocytosis), vascular causes (such as pial angiomatosis, ANCA-related vasculitis, and Moyamoya disease), and other disorders like spontaneous intracranial hypotension and posterior reversible encephalopathy syndrome. Despite the nonspecific nature of imaging findings associated with meningeal lesions, narrowing down the differential diagnoses is crucial, as each condition requires a tailored and specific treatment approach.

Meningitis caused by Candida dubliniensis in a patient with liver cirrhosis: A case report and review of the literature

Candida meningitis is almost always caused by Candia albicans, but other species, such as Candida dubliniensis, can cause it on rare occasions. C. dubliniensis is increasingly linked to immunocompromised hosts but also affects immunocompetent hosts. To the best of our knowledge, we present the ninth (9th) case of C. dubliniensis meningitis, the first from Saudi Arabia. A 70-year-old woman with multiple comorbidities presented with confusion, poor oral intake, and left upper limb swelling for two weeks. C. dubliniensis was isolated and treated with liposomal amphotericin and anidulafungin. The scarcity of such infections makes the best treatment regimen undetermined.

2012 Elsevier Ltd

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Challenging Treatment of Disseminated Aspergillosis in a Child With Nephrotic Syndrome

INTRODUCTION

Central nervous system (CNS) aspergillosis is an opportunistic infection with an increasing incidence and a high mortality rate. It is seen in immunocompromised patients as well as in immunocompetent patients. Here, we present disseminated aspergillosis in a child with nephrotic syndrome treated with long-term and aggressive systemic antifungal treatment and intraventricular (IVent) liposomal amphotericin B (L-AmB) as well as surgical excision and drainage due to difficulty in management.

CASE REPORT

A 10-year-old boy with nephrotic syndrome on steroid therapy was admitted with limping and weakness. The cranial magnetic resonance imaging showed multiple intraparenchymal scattered abscesses. The largest one was excised and drained. Abscess culture revealed Aspergillus fumigatus and histopathological examination revealed septate hyphae compatible with Aspergillosis. Intravenous (IV) voriconazole was started, and IV L-AmB was added. The size of lesions and perilesional edema continued to increase, and then IVent L-AmB was added. With IVent and systemic antifungal treatment, regression of the lesions was observed. He was followed up with oral voriconazole and weekly IVent L-AmB. After 2 and a half months, he was re-operated because of increased lesion size, number and perilesional edema, and IV voriconazole and other salvage antifungal therapies were started. Since the lesions had decreased and remained stable, IV voriconazole was switched to oral therapy, and he was followed up as an outpatient. Immunodeficiency diseases were excluded by immunological and genetic tests.

CONCLUSION

Management of central nervous system aspergillosis can be challenging despite long-term and aggressive systemic and IVent antifungal treatment as well as surgical excision and drainage.

Toll-like receptor 4 and CD11b expressed on microglia coordinate eradication of Candida albicans cerebral mycosis

The fungal pathogen Candida albicans is linked to chronic brain diseases such as Alzheimer's disease (AD), but the molecular basis of brain anti-Candida immunity remains unknown. We show that C. albicans enters the mouse brain from the blood and induces two neuroimmune sensing mechanisms involving secreted aspartic proteinases (Saps) and candidalysin. Saps disrupt tight junction proteins of the blood-brain barrier (BBB) to permit fungal brain invasion. Saps also hydrolyze amyloid precursor protein (APP) into amyloid β (Aβ)-like peptides that bind to Toll-like receptor 4 (TLR4) and promote fungal killing in vitro while candidalysin engages the integrin CD11b (Mac-1) on microglia. Recognition of Aβ-like peptides and candidalysin promotes fungal clearance from the brain, and disruption of candidalysin recognition through CD11b markedly prolongs C. albicans cerebral mycosis. Thus, C. albicans is cleared from the brain through innate immune mechanisms involving Saps, Aβ, candidalysin, and CD11b.

Endemic mycoses in children in North America: a review of radiologic findings

Clinically significant endemic mycoses (fungal infections) in the United States (U.S.) include Blastomyces dermatitidis, Histoplasma capsulatum, and Coccidioides immitis/posadasii. While the majority of infections go clinically unnoticed, symptomatic disease can occur in immunocompromised or hospitalized patients, and occasionally in immune-competent individuals. Clinical manifestations vary widely and their diagnosis may require fungal culture, making the rapid diagnosis a challenge. Imaging can be helpful in making a clinical diagnosis prior to laboratory confirmation, as well as assist in characterizing disease extent and severity. In this review, we discuss the three major endemic fungal infections that occur in the U.S., including mycology, epidemiology, clinical presentations, and typical imaging features with an emphasis on the pediatric population.

Candida meningitis/ventriculitis over a decade. Increased morbidity and length of stay a concern

AIM

The primary aim of this study was to review the diagnosis, management and outcome of Candida meningitis/ventriculitis in our hospital over a ten-year period.

MATERIALS AND METHODS

We retrospectively reviewed all culture and 18s rRNA nucleic acid positive CSF specimens processed between 1st January 2010 and 31st December 2020. Patient records were subsequently reviewed to assess the significance of the isolate.

RESULTS

Of 851 culture-positive cerebrospinal fluid (CSF) specimens, Candida spp. were isolated from 29 (3.4%), representing infection in 12 patients. One culture-negative specimen was positive for Candida on 18s rRNA testing. Of the 13 patients, eight were male; 61.5% and the median age was 47 years; range: 20-70. The median interval from admission to onset of infection and culture positivity was 24 days (range: 1-63 days). All patients had a central nervous system (CNS) device in situ (external ventricular drain: 11; ventriculoperitoneal shunt: 1; lumbar drain: 1). Four were colonised with Candida spp. before meningitis/ventriculitis diagnosis, from wounds (n = 3), respiratory (n = 3), and urine (n = 1) specimens. On culture, the most common species was Candida albicans (n = 8), followed by C. parapsilosis (n = 2), C. tropicalis (n = 1), and C. dubliniensis (n = 1). The median number of follow-up CSFs per patient was nine (range; 3-22), with a median of 6 days to CSF sterility (range 3-10 days). Treatment included; liposomal amphotericin B (n = 5), fluconazole (n = 2), liposomal amphotericin B, and flucytosine (n = 2), liposomal amphotericin B, fluconazole and flucytosine (n = 3), and intra-ventricular amphotericin B (n = 1). Median treatment duration was 25 days (range 11-76) and CNS device removal occurred in 12 patients. The median length-of-stay (LOS) was 58 days (range 24-406). On discharge, moderate to severe disability (Modified Rankin Scale [mRS] 3-5) was evident in eight patients. Two patients died and one was lost to follow-up.

CONCLUSION

Meningitis/ventriculitis due to Candida spp. is an uncommon but challenging infection, usually associated with a device, increased morbidity, LOS, and necessitating prolonged treatment. Neurosurgeons need to be aware of these issues in managing and in communicating with such complex patients.

The first case of Wickerhamomyces anomalus fungemia in Iran in an immuneodeficient child, a review on the literature

The incidence of invasive candidiasis in pediatric patients is increasing and is associated with significant morbidity and mortality. C. pelliculosa has been rarely reported as a human pathogen, however, it has been associated with serious nosocomial infections and clonal outbreaks with poor clinical outcomes in immunocompromised children were reported. Here, we describe the first case of candidemia due to Candida pelliculosa in a 5-year-old immunocompromised male suffered from Griscelli syndrome with hemophagocytic syndrome hospitalized in the pediatric intensive care unit (PICU), Tehran, Iran. In addition, the history of reported cases or case-series due to C. pelliculosa is reviewed.

Cerebral aspergillosis after heart-lung transplantation in a child: Case report with 3-year follow-up and literature review

There are limited cases of heart-lung transplantation (HLT) in children worldwide owing to lack of donors, demanding surgical teamwork, and arduous post-operative management. Post-transplant management difficulties stem from the possible development of several post-operative complications, with infection being a common complication. Intracranial fungal infections are difficult to diagnose and prone to treatment delays because of their relatively insidious onset and atypical clinical presentation. Here, we present a case of a cerebral infection developed 3 months after HLT in a 10-year-old child, showing no positive results on conventional imaging or cerebrospinal fluid (CSF) examination and culture. On metagenomic next-generation sequencing of the cerebrospinal fluid, the causative organism was finally determined as Aspergillus. After administering 1-year anti-Aspergillus treatment, no recurrence of intracranial fungal infection was noted during the 3-year follow-up. This case illustrates the multifaceted diagnostic techniques for cerebral aspergillosis after HLT and shows the significance of dynamic monitoring of symptoms, such as headache, and of metagenomic sequencing results, trends in intracranial pressure and (1-3)-β-D-glucan levels for guiding diagnosis and treatment.

Clinical characteristics of central nervous system candidiasis due to Candida albicans in children: a single-center experience

BACKGROUND

Central nervous system candidiasis due to Candida albicans (CNSC) in children is easily misdiagnosed and is associated with poor outcomes and a high mortality rate. There is no big data research or systematic review of CNSC.

METHODS

Patients diagnosed as CNSC with positive culture results of Candida albicans in Beijing Children's Hospital affiliated to Capital Medical University from March 2010 to March 2019 were included. Patients receiving immunosuppressive therapy or transplantation, or with malignant tumours were excluded. We analysed the clinical characteristics, follow-up results, drug susceptibility tests and whole-exome sequencing (WES) results.

RESULTS

Thirty-three definitive patients were enrolled, including 22 males and 11 females. Twenty-five patients suffered from CNSC when they were less than 1 year old, and a total of 29 patients had high-risk factors. The main clinical manifestations were fever, convulsions, and positive neurological signs. Twenty-two patients had CNS infections alone, and 11 patients had CNS infections combined with invasive infections involving multiple sites. Twenty-seven cases had a positive CSF and/or blood culture at our hospital. All strains were susceptible to fluconazole, and 2 strains had intermediate susceptibility to voriconazole. As for amphotericin B, all the strains were wild type (WT). WES of 16 patients revealed 2 cases with CARD9 mutations, who suffered from recurrent onychomycosis or thrush before.

CONCLUSION

CNSC mostly existed in children younger than 1 year old, who all had underlying risk factors. CNSC patients with onset at an older age or with recurrent superficial fungal infections might have primary immunodeficiency.

Intramedullary histoplasmosis lesion in children: A case report

Background:

Histoplasmosis is a fungal disease endemic in some regions of the United States of America, Canada, and Latin America. The geographic characteristics, humidity, soil, and climate are responsible for such distribution. In Brazil, there are case reports of histoplasmosis throughout its territory, being considered an endemic region. It is considered an opportunistic disease, affecting mostly immunocompromised patients. To the present date, scientific publications dealing with pediatric cases of histoplasmosis are restricted to case series. Spinal cord injuries caused by histoplasmosis are rare, even in the adult population, being described in few studies.

Case Description:

The present report deals with a 4-year-old patient, from the southeast region of Brazil, who started a condition of fever, weight loss, cervicobrachialgia, and symmetrical tetraparesis, with evolution over 2 months. In the diagnostic investigation, she was found to have primary immunodeficiency and neuroimaging examinations showed a cervical spinal cord lesion at the level of C4-C6. The anatomopathological diagnosis of histoplasmosis was possible after surgery for decompression and biopsy of the lesion.

Conclusion:

According to our research, there are no reports in the literature that address the situation of spinal cord compression syndrome due to histoplasmosis in the pediatric population.

Clonal spread of carbapenem-resistant Klebsiella pneumoniae among patients at admission and discharge at a Vietnamese neonatal intensive care unit

Background

The increasing prevalence of carbapenem-resistant Enterobacteriaceae (CRE) is a growing problem globally, particularly in low- to middle-income countries (LMICs). Previous studies have shown high rates of CRE colonisation among patients at hospitals in LMICs, with increased risk of hospital-acquired infections.

Methods

We isolated carbapenem-resistant Klebsiella pneumoniae (CRKP) from faecal samples collected in 2017 from patients at admission and discharge at a Vietnamese neonatal intensive care unit (NICU). 126 CRKP were whole-genome sequenced. The phylogenetic relationship between the isolates and between clinical CRKP isolates collected in 2012–2018 at the same hospital were investigated.

Results

NDM-type carbapenemase-(61%) and KPC-2-encoding genes (41%) were the most common carbapenem resistance genes observed among the admission and discharge isolates. Most isolates (56%) belonged to three distinct clonal clusters of ST15, carrying bla_KPC-2, bla_NDM-1 and bla_NDM-4, respectively. Each cluster also comprised clinical isolates from blood collected at the study hospital. The most dominant ST15 clone was shown to be related to isolates collected from the same hospital as far back as in 2012.

Conclusions

Highly resistant CRKP were found colonising admission and discharge patients at a Vietnamese NICU, emphasising the importance of continued monitoring. Whole-genome sequencing revealed a population of CRKP consisting mostly of ST15 isolates in three clonally related clusters, each related to blood isolates collected from the same hospital. Furthermore, clinical isolates collected from previous years (dating back to 2012) were shown to likely be clonally descended from ST15 isolates in the largest cluster, suggesting a successful hospital strain which can colonise inpatients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-021-01033-3.

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.

Multidrug-resistant organisms in urinary tract infections in children

The global spread of multidrug-resistant organisms has led to an increase in urinary tract infections (UTIs) in children that are difficult to treat. This review explores the current literature regarding multidrug-resistant UTIs in childhood and proposes an approach to management. Multidrug-resistant organisms include a wide range of potential urinary tract pathogens and, while most literature on drug resistance in UTIs during childhood has focused on extended-spectrum beta-lactamase producing organisms, in this review, we have included a discussion of multidrug resistance including and beyond beta-lactamase production. We provide definitions for multidrug-resistant organisms in line with current consensus guidelines and summarise clinically relevant mechanisms of resistance. Additionally, in this review, we outline the global epidemiology of multidrug-resistant UTIs in children, summarising published prevalence rates, which range from 5 to 90% in different settings. Finally, we also critically review the evidence on risk factors for colonisation and infection of the urinary tract with multidrug-resistant organisms, including prior antibiotic use, hospitalisation and underlying urological malformations. We also highlight multidrug-resistant UTI occurring in children without any identifiable risk factors, reflecting an increasing prevalence of colonisation with these organisms in the general community. Taken as a whole, this emphasises a need for careful and evidence-based use of antibiotics when treating UTIs in children and, to aide clinicians, we have outlined here potential management strategies for when infection with a multidrug-resistant organism is suspected or confirmed.

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.

Cryptococcal infections in children: retrospective study and review from Australia

Aim: Cryptococcosis causes significant morbidity and mortality worldwide, but pediatric data are limited. Methods: A retrospective literature review of Australian pediatric cryptococcosis and additional 10-year audit of cases from a large pediatric network. Results: 22 cases of cryptococcosis in children were identified via literature review: median age was 13.5 years (IQR 7.8-16 years), 18/22 (82%) had meningitis or central nervous system infection. Where outcome was reported, 11/18 (61%) died. Of six audit cases identified from 2008 to 2017, 5 (83%) had C. gattii disease and survived. One child with acute lymphoblastic leukemia and C. neoformans infection died. For survivors, persisting respiratory or neurological sequelae were reported in 4/6 cases (67%). Conclusion: Cryptococcosis is uncommon in Australian children, but is associated with substantial morbidity.

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.

CARD9+ microglia promote antifungal immunity via IL-1β- and CXCL1-mediated neutrophil recruitment

The C-type lectin receptor–Syk adaptor CARD9 facilitates protective antifungal immunity within the central nervous system (CNS), as human CARD9-deficiency causes fungal-specific CNS-targeted infection susceptibility. CARD9 promotes neutrophil recruitment to the fungal-infected CNS, which mediates fungal clearance. Here, we investigated host and pathogen factors that promote protective neutrophil recruitment during Candida albicans CNS invasion. IL-1β was essential for CNS antifungal immunity by driving CXCL1 production, which recruited CXCR2-expressing neutrophils. Neutrophil-recruiting IL-1β and CXCL1 production was induced in microglia by the fungal-secreted toxin Candidalysin, in a p38-cFos-dependent manner. Importantly, microglia relied on CARD9 for production of IL-1β, via both Il1b transcriptional regulation and inflammasome activation, and of CXCL1 in the fungal-infected CNS. Microglia-specific Card9 deletion impaired IL-1β and CXCL1 production and neutrophil recruitment, and increased CNS fungal proliferation. Taken together, an intricate network of host-pathogen interactions promotes CNS antifungal immunity, which is impaired in human CARD9-deficiency leading to CNS fungal disease.

Pediatric Giant Cerebral Candida Abscess: A Case Report

Fungal infections of the central nervous system and pediatric brain abscess are rare but serious conditions in terms of morbidity and mortality that need immediate diagnosis and treatment. It can be seen in congenital or acquired immunosuppressed patients as opportunistic infections as well as in low-birth-weight, premature infants with ventriculoperitoneal shunt, external ventricular drainage, or with a history of craniotomy. Our aim is to emphasize the giant cerebral Candida abscess of a 13-month-old female infant who previously had eight ventriculoperitoneal shunt operations due to hydrocephalus. The patient was taken to pediatric emergency care with complaints of feeding difficulty and discomfort and was hospitalized due to the detection of an intracranial mass by contrast-enhanced brain tomography. After total excision of the mass with its capsule, the patient was pathologically diagnosed with Candida abscess, and the treatment was started. The patient was discharged by the end of the 6th week.

Candidemia in the cancer patient: diagnosis, treatment, and future directions

INTRODUCTION

The presence of Candida species in the blood is known as candidemia and may constitute a medical emergency for patients with cancer. Despite advances in diagnosis and treatment of this fungal infection, mortality remains unacceptably high. Areas covered: This paper reviews recent advances in molecular diagnostics to detect species of Candida as well as novel antifungal agents that have been developed to address candidiasis. We also review prophylaxis strategies to prevent candidiasis in high-risk cancer patients. Expert commentary: We draw from our own experiences treating candidemia in the cancer patient and review novel diagnostic strategies involving molecular resonance and mass spectroscopy. We also explore novel chemoprophylaxis and treatment options, including new drugs such as rezafungin and SCY-078. We also look ahead, to examine how this condition will be managed in the years ahead.

Fungal infections in pediatric neurosurgery

INTRODUCTION

Invasive mycosis of the central nervous system represent a diverse group of diseases that have gradually emerged as not only opportunistic infections in patients with immune susceptibility due to congenital and acquired deficiency, immunomodulation, solid organ and stem cell transplantation, hematological malignancies, and chronic steroid use but also in selected risk populations such as low weight preterm infants, patients with shunted hydrocephalus and external ventricular drainages, skull base surgery, and head injury.

OBJECTIVES

The purpose of this review is to familiarize the pediatric neurosurgeon with the most common mycosis and their clinical scenarios which can be encountered in the clinical practice, with special emphasis on clinical, radiological, and laboratory diagnosis beyond classical microorganism cultures as well as options in medical and surgical treatment given the high incidence of morbidity and mortality associated with these challenging entities.

METHODS

We conducted an online database review (Ovid, PubMed) gathering relevant English language literature published in the last 20 years with special emphasis on recent breakthroughs in the diagnosis and treatment of invasive mycosis of the CNS as well as reported cases within the pediatric neurosurgical literature and their surgical management.

RESULTS

Fungal agents capable of invading the CNS can behave as aggressive entities with rapid progression manifesting as overwhelming meningoencephalitis with vascular compromise or can lead to space-occupying lesions with abscess formation which require prompt diagnosis by either laboratory identification of the components of these biological agents and their host response or by obtaining tissue specimens for microbiological identification which may not be straightforward due to prolonged culture time.

CONCLUSION

Following a high degree of suspicion with prompt initiation of antifungal agents and reversal of potential immunosuppressant therapies along with neurosurgical evacuation of intracranial collections or removal of infected hardware (CSF shunts) can lead to more optimistic outcomes of these complex clinical scenarios.

Neuroinfections caused by fungi

BACKGROUND

Fungal infections of the central nervous system (FIs-CNS) have become significantly more common over the past 2 decades. Invasion of the CNS largely depends on the immune status of the host and the virulence of the fungal strain. Infections with fungi cause a significant morbidity in immunocompromised hosts, and the involvement of the CNS may lead to fatal consequences.

METHODS

One hundred and thirty-five articles on fungal neuroinfection in PubMed, Google Scholar, and Cochrane databases were selected for review using the following search words: "fungi and CNS mycoses", CNS fungal infections", "fungal brain infections", " fungal cerebritis", fungal meningitis", "diagnostics of fungal infections", and "treatment of CNS fungal infections". All were published in English with the majority in the period 2000-2018. This review focuses on the current knowledge of the epidemiology, clinical presentations, diagnosis, and treatment of selected FIs-CNS.

RESULTS

The FIs-CNS can have various clinical presentations, mainly meningitis, encephalitis, hydrocephalus, cerebral abscesses, and stroke syndromes. The etiologic factors of neuroinfections are yeasts (Cryptococcus neoformans, Candida spp., Trichosporon spp.), moniliaceous moulds (Aspergillus spp., Fusarium spp.), Mucoromycetes (Mucor spp., Rhizopus spp.), dimorphic fungi (Blastomyces dermatitidis, Coccidioides spp., Histoplasma capsulatum), and dematiaceous fungi (Cladophialophora bantiana, Exophiala dermatitidis). Their common route of transmission is inhalation or inoculation from trauma or surgery, with subsequent hematogenous or contiguous spread. As the manifestations of FIs-CNS are often non-specific, their diagnosis is very difficult. A fast identification of the etiological factor of neuroinfection and the application of appropriate therapy are crucial in preventing an often fatal outcome. The choice of effective drug depends on its extent of CNS penetration and spectrum of activity. Pharmaceutical formulations of amphotericin B (AmB) (among others, deoxycholate-AmBd and liposomal L-AmB) have relatively limited distribution in the cerebrospinal fluid (CSF); however, their detectable therapeutic concentrations in the CNS makes them recommended drugs for the treatment of cryptococcal meningoencephalitis (AmBd with flucytosine) and CNS candidiasis (L-AmB) and mucormycosis (L-AmB). Voriconazole, a moderately lipophilic molecule with good CNS penetration, is recommended in the first-line therapy of CNS aspergillosis. Other triazoles, such as posaconazole and itraconazole, with negligible concentrations in the CSF are not considered effective drugs for therapy of CNS fungal neuroinfections. In contrast, clinical data have shown that a novel triazole, isavuconazole, achieved considerable efficacy for the treatment of some fungal neuroinfections. Echinocandins with relatively low or undetectable concentrations in the CSF do not play meaningful role in the treatment of FIs-CNS.

CONCLUSION

Although the number of fungal species causing CNS mycosis is increasing, only some possess well-defined treatment standards (e.g., cryptococcal meningitis and CNS aspergillosis). The early diagnosis of fungal infection, accompanied by identification of the etiological factor, is needed to allow the selection of effective therapy in patients with FIs-CNS and limit their high mortality.

The pathogenicity ofAspergillus fumigatus, drug resistance, and nanoparticle delivery

The genus Aspergillus includes fungal species that cause major health issues of significant economic importance. These microorganisms are also the culprit for production of carcinogenic aflatoxins in grain storages, contaminating crops, and economically straining the production process. Aspergillus fumigatus is a very important pathogenic species, being responsible for high human morbidity and mortality on a global basis. The prevalence of these infections in immunosuppressed individuals is on the rise, and physicians struggle with the diagnosis of these deadly pathogens. Several virulence determinants facilitate fungal invasion and evasion of the host immune response. Metabolic functions are also important for virulence and drug resistance, since they allow fungi to obtain nutrients for their own survival and growth. Following a positive diagnostic identification, mortality rates remain high due, in part, to emerging resistance to frequently used antifungal drugs. In this review, we discuss the role of the main virulence, drug target, and drug resistance determinants. We conclude with the review of new technologies being developed to treat aspergillosis. In particular, microsphere and nanoparticle delivery systems are discussed in the context of improving drug bioavailability. Aspergillus will likely continue to cause problematic infections in immunocompromised patients, so it is imperative to improve treatment options.

Candidiasis of the Central Nervous System in Neonates and Children with Primary Immunodeficiencies

PURPOSE OF REVIEW

Candida infections of the central nervous system (CNS) are a life-threatening complication of invasive infections that most often affect vulnerable groups of patients, including neonates and children with primary immunodeficiency disorders (PID). Here, we review the currently known risk factors for CNS candidiasis, focusing predominantly on the PID caused by biallelic mutations in CARD9.

RECENT FINDINGS

How the CNS is protected itself against fungal invasion is poorly understood. CARD9 promotes neutrophil recruitment and function, and is the only molecule shown to be critical for protection against CNS candidiasis in humans thus far.

SUMMARY

Fundamental insights into the pathogenesis of CNS candidiasis gained from studying rare CARD9-deficient patients has significant implications for other patients at risk for this disease, such as CARD9-sufficient neonates. These findings will be important for the development of adjunctive immune-based therapies, which are urgently needed to tackle the global burden of invasive fungal diseases.

Preliminary experience of tigecycline treatment in critically ill children with ventilator-associated pneumonia

Objective

Ventilator-associated pneumonia (VAP) is a life-threatening complication for children who are treated in a paediatric intensive care unit. Tigecycline treatment of children with VAP has not been well studied. This study aimed to describe tigecycline use in children with VAP in a tertiary care hospital.

Methods

We conducted a retrospective chart review in a tertiary hospital from May 1, 2012 to May 1, 2017.

Results

Twenty-four children (20 girls) with median age of 8 months (range, 27 days to 6 years and 9 months) were treated with tigecycline. In-hospital mortality was 41.7% (10/24). The primary diagnosis was congenital heart disease (15/24). A total of 70.8% (17/24) of patients received a loading dose (1.5 mg/kg), followed by 1 mg/kg every 12 hours. The median duration of tigecycline therapy was 10.75 days (range, 3–21.5 days). Sulperazone was the most frequently used concomitant antibiotic. Eighteen pathogens were isolated in 16 cases. Tigecycline therapy failed in 41.6% (10/24) of patients and 20.8% (5/24) died. The pathogen was eradicated in 37.5% (6/16) of patients. No serious adverse effects were detected.

Conclusion

Tigecycline combined with other agents as salvage therapy in children with VAP is well tolerated. Our preliminary results show a positive clinical response.

Infant Central Nervous System Aspergillosis with First-episode of Intracranial Hemorrhage: A case report

RATIONALE

Central nervous system (CNS) aspergillosis has the characteristics of multifocality, polymorphism, and coexistence of pathological types, and missed diagnosis and misdiagnosis frequently occur at the initial stage. The thesis reports a rare case of infant infection of CNS aspergillosis with the first-episode of intracranial hemorrhage.

PATIENT CONCERNS

An 11-month-old female infant suffered convulsion and coma two days after the onset of fever and emesis. Its cranial computed tomography (CT) displayed subdural hemorrhage in the left tentorium cerebelli and tests indicated normal cerebrospinal fluid (CSF). Three days after being hospitalized, the infant had difficulty breathing and its CT presents consolidation in the right lung. However, treatment with ceftriaxone (ivgtt) had no effect on the baby.

DIAGNOSIS

The patient's bronchoalveolar lavage fluid (BALF) was cultured into Aspergillus spp, its galactomannan (GM) antigen in CSF counted 3.0, higher than that in BALF which counted 2.6, and cranial magnetic resonance imaging (MRI) revealed multiple ring reinforced tubercles in sulci. Hence it was clinically diagnosed with CNS aspergillosis.

INTERVENTIONS

Voriconazole for intravenous injection. After the intravenous injection, its trough concentration was 4.2 μg/mL, and it was within the recommended range.

OUTCOMES

After one week's treatment with voriconazole, the infant's consciousness was improved. Four weeks later, with normothermia and clear consciousness, the patient was discharged. With oral administration of voriconazole up to 16 weeks, its physical state suggests no relapse and cranial MRI indicated disappearance of nodules in sulci.

LESSONS

CNS aspergillosis with first-episode of intracranial hemorrhage probably leads to misdiagnosis and GM test combined with cranial MRI can augment its accuracy in the early diagnosis.