Fungal Infections Found During Autopsies: A Report from Spain

Fungi are emerging as important nosocomial pathogens, particularly in patients with cancer, in transplant recipients, in patients infected with the human immunodeficiency virus (HIV), and in those admitted to intensive care units. However, the exact incidence of nosocomial mycoses has been difficult to assess because of the low sensitivity of mycological laboratory methods and the difficulty in obtaining tissue from seriously ill patients for histopathologic examination. To assess the prevalence and type of fungal infections at our institution, we did a retrospective survey of autopsy findings for patients who died in our hospital during the last 8 years. We reviewed the records of all autopsies performed in our institution between January 1986 and December 1993. Our hospital is a tertiary care teaching institution with an average of 48,000 admissions per year. The following information was obtained from each record: age and sex of the deceased, underlying disease, presence of fungal infection, and type of fungal infection and organs involved. Tissue sections were stained with hematoxylin and eosin and with special methods such as periodic acid-Schiff reaction and/or Grocott-Gomori methenamine-silver nitrate staining. A diagnosis of candidiasis was made if blastoconidia and/or pseudohyphae were seen in tissue samples; a diagnosis of aspergillosis was made if tissue invasion by dichotomously branching hyaline septate hyphae was seen; and a diagnosis of zygomycosis was made if tissue invasion by predominantly aseptate hyphae with nonparallel borders was seen. Mycoses were defined as superficial, deep mucosal, invasive, or disseminated. Superficial mycoses involved skin and the mucosa of the body orifices (i.e., mouth and vagina). Deep mucosal mycoses involved the mucosa of the digestive tract, the urinary tract, trachea, and bronchi. Invasive mycoses involved the parenchyma of the internal organs. Disseminated mycoses involved at least two noncontiguous organs.