Upon completion of the chapter, the reader will be able to:
Differentiate epidemiologic differences and host risk factors for acquisition of primary and opportunistic invasive fungal pathogens.
Recommend appropriate empiric or targeted antifungal therapy for the treatment of invasive fungal infections.
Describe the components of a monitoring plan to assess effectiveness and adverse effects of pharmacotherapy for invasive fungal infections.
Evaluate the role of antifungal prophylaxis in the prevention of opportunistic fungal pathogens.
Invasive fungal infection or invasive mycoses are general terms for diseases caused by invasion of living tissue by fungi. In contrast to superficial mycoses (see Chapter 83), invasive fungal infections are much less common, but are of greater medical concern because of their disproportionately higher severity and mortality. Approximately 1.5 million people die each year from the 10 most common invasive fungal infections, which is higher than World Health Organization mortality estimates for tuberculosis (1.4 million) or malaria (1.2 million).1 However, these numbers probably underestimate the actual mortality burden of invasive fungal disease considering that the four most common infections (cryptococcosis, invasive candidiasis, invasive aspergillosis, and Pneumocystis jiroveci pneumonia) are often underdiagnosed and not reportable diseases to public health agencies (Table 84–1).
Table 84–1Invasive Mycoses |Favorite Table|Download (.pdf) Table 84–1 Invasive Mycoses
Primary (Endemic) Invasive Fungi
Coccidioides immitis/Coccidioides posadasiia
Opportunistic Invasive Fungi
Candida species (C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, C. krusei, and others)a
Trichosporon spp. and others
Aspergillus fumigatus, Aspergillus terreus, Aspergillus flavus, and other speciesa
Fusarium solani and Fusarium oxysporum
Mucorales (formally zygomycosis) (Mucor, Absidia, Rhizopus, Cunninghamella, and Rhizomucor)
Pseudallescheria boydii (Scedosporium spp.)
Pneumocystis jiroveci (formerly P. carinii)a
Invasive fungal infections are broadly categorized as either primary or opportunistic mycoses. Primary invasive fungal infections develop following exposure to fungal spores or conidia in the soil that, when disturbed, can become aerosolized and inhaled leading to infection, even in an immunocompetent patient exposed to a sufficient inoculum. Because these fungi are in specific soil types in select geographic areas, they are also referred to as endemic fungi. In the United States, three Genera (Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides immitis/Coccidioides posadasii) account for most of these infections (see Table 84–1).
In contrast, opportunistic fungal infections are most frequently encountered in setting of compromised host immune defenses, and are caused by a wider spectrum of less virulent fungal species that rarely cause infection in healthy patients (see Table 84–1). Hence, the spectrum, severity, and outcome of opportunistic fungal infections are strongly influenced ...