SPECIES DISTRIBUTION

George R Thompson, III, MD: You mentioned some of the cryptic species for Aspergillus. So, for those who don’t know what cryptic species are, those are organisms that microscopically or macroscopically look like one particular species, but when sequenced, they’re a non-fumigatus or an unusual species. You mentioned Aspergillus nidulans also in that group. What is the typical Aspergillus species distribution pattern that you see in the pediatric population? Is it different than adults? Is it different than the transplant population? What’s your approach to the different species responsible for disease?

Antonio Arrieta, MD: This has changed over time, George, and I don’t think I have a very good explanation as to why that change has happened. But earlier data collected in the nineties from St. Jude’s Children’s Hospital suggested that Aspergillus flavus was more common in pediatrics.¹⁶ These data were supported by investigators from the Hospital for Sick Children at the University of Toronto, where they found similar data.¹⁷ But more recently, we now have a very similar microbiologic profile in pediatrics as adults (as shown in Figure 1). Now, Aspergillus fumigatus is our most common species. Our second most common is Aspergillus flavus.¹⁸

Figure 1. Distribution of Aspergillus species in pediatric patients.¹⁸

Adapted from Burgos et al.

One of the things that we have noticed with interest is that when we do cultures, often we recover one fungus and just one species. When we send some sophisticated molecular testing that we will discuss  later, all of a sudden the molecular testing suggests the presence of two or three different species for the same patient and sometimes actually two different fungal pathogens.

TABLE OF CONTENTS

• INTRODUCTION
• INVASIVE MOLD INFECTIONS: ON THE RISE IN CHILDREN (including risk factors)
• SPECIES DISTRIBUTION
• ANTIFUNGAL PROPHYLAXIS STRATEGIES
• CLINICAL PRESENTATION AND DIAGNOSIS OF INVASIVE MOLD DISEASE IN CHILDREN
• EMPIRIC THERAPY
• TARGETED TREATMENT (including isavuconazole for invasive mold infections)
• PHARMACOLOGY OF ANTIFUNGALS USED IN CHILDREN
• OVERALL MANAGEMENT OF ASPERGILLOSIS AND MUCORMYCOSIS
• DOSING AND ADMINISTRATION OF ANTIFUNGALS USED IN CHILDREN (including voriconazole, posaconazole, and isavuconazole)  
• CAREGIVER AND PATIENT EDUCATION (including overall education, reducing the risk of infection at home, and setting expectations for therapy)
• REFERENCES

Faculty

George R. Thompson, III, MD

Professor of Medicine
University of California, Davis, School of Medicine
Sacramento, California

Antonio C. Arrieta, MD

Division Chief
Pediatric Infectious Diseases
Children’s Hospital of Orange County (CHOC)
Orange, California

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