Diagnostic pathology of microsporidiosis.

Microsporidia are ubiquitous spore-forming parasites that are important worldwide pathogens in the HIV/AIDS pandemic. They are also increasingly being seen in HIV(-) individuals. Infection has been documented in almost every tissue and organ in the body and in a broad spectrum of cell types, including epithelial, mesenchymal, and neural. Microsporidia elicit a wide range of pathology, e.g., inflammation and cell death, and symptoms, e.g., shortness of breath, sinusitis, and diarrhea with wasting. Untreated, microsporidiosis has been documented as a cause of death.