Although substantial progress has been made in reducing the impact of protozoal and helminthic infections, parasitic diseases remain a major cause of morbidity and mortality worldwide, particularly in impoverished tropical regions. In the United States, parasitic diseases are most often…
Definition Dematiaceous fungi represent a large group of fungal organisms characterized by the presence of abundant melanin in the cell wall. This melanin gives rise to a brown-black coloration on artificial culture media and in histopathologic specimens. A related term,…
Definition Pneumocystis jirovecii is a fungus that causes pneumonia almost exclusively in immunodeficient patients. Pneumocystis pneumonia (PCP) has been the most common life-threatening opportunistic infection in persons infected with human immunodeficiency virus (HIV), especially those with acquired immunodeficiency syndrome (AIDS).…
Definition Mucormycosis is the unifying term used to describe infections caused by fungi belonging to the order Mucorales. Mucorales typically cause aggressive, acute-onset, frequently fatal or disfiguring, angioinvasive infections, especially in immunosuppressed hosts. Epidemiology Mucorales fungi are distributed worldwide and…
Definition Aspergillosis is a disease caused by one or more of the species of the genus Aspergillus . Sporelike structures called conidia are aerosolized from the mold form of the organism growing in the environment. When conidia reach tissue, they…
Definition Candidiasis encompasses a wide variety of clinical syndromes caused by yeasts of the genus Candida . Of the species that cause infection in humans, Candida albicans is the most common; Candida glabrata, Candida parapsilosis , and Candida tropicalis are…
Definition Cryptococcosis occurs most often in persons who are immunosuppressed, especially individuals who are infected with human immunodeficiency virus (HIV; see Chapter 358 ). Meningoencephalitis is the most common clinical manifestation, but the lungs and other organs can be involved…
Blastomycosis Definition Blastomycosis (North American blastomycosis) is an endemic mycosis that primarily causes infection of the lungs and skin and, less commonly, infection of the osteoarticular and genitourinary systems ( Table 308-1 ). TABLE 308-1 BLASTOMYCOSIS: CLINICAL CHARACTERISTICS AND TREATMENT…
Methods for in vitro testing of antifungal susceptibility are available as standardized tools. A variety of assays also are available for therapeutic monitoring of drug levels in the serum and other bodily fluids. The increasing prevalence of drug resistance requires careful…
Definition Nocardiosis refers to infections caused by Nocardia spp. Nocardia most commonly causes pneumonia but also can infect the central nervous system (CNS) and the skin. Less commonly, this organism can disseminate throughout the body. These infections usually occur in…