Aspergillosis is an opportunistic, sometimes life-threatening infection caused by fungi of the genus Aspergillus, usually A. fumigatus, A. flavus, or A. niger. It occurs in four major forms:
Aspergillus may cause infection of the ear (otomycosis), cornea (mycotic keratitis), or prosthetic heart valve (endocarditis); pneumonia (especially in those receiving an immunosuppressant, such as an antineoplastic drug or high-dose steroid therapy); sinusitis; and brain abscesses.
The prognosis varies with each form. Occasionally, aspergilloma causes fatal hemoptysis.
Aspergillus is found worldwide, commonly in fermenting compost piles and damp hay. It’s transmitted by inhalation of fungal spores or, in aspergillosis endophthalmitis, by the invasion of spores through a wound or other tissue injury.
Aspergillus produces infection only in persons who become especially vulnerable to it. Such vulnerability can result from excessive or prolonged use of antibiotics, glucocorticoids, or other immunosuppressants; from radiation; from such conditions as acquired immunodeficiency syndrome, Hodgkin’s disease, leukemia, azotemia, alcoholism, sarcoidosis, bronchitis, or bronchiectasis; from organ transplants; and, in aspergilloma, from tuberculosis or another cavitary lung disease.
The incubation period in aspergillosis ranges from a few days to weeks. In aspergilloma, colonization of the bronchial tree with Aspergillus produces plugs and atelectasis and forms a tangled ball of hyphae (fungal filaments), fibrin, and exudate in a cavity left by a previous illness such as tuberculosis. Characteristically, aspergilloma either produces no symptoms or mimics tuberculosis, causing a productive cough and purulent or blood-tinged sputum, dyspnea, empyema, and lung abscesses.
Allergic aspergillosis causes wheezing, dyspnea, cough with some sputum production, pleural pain, and fever.
Aspergillosis endophthalmitis usually appears 2 to 3 weeks after an eye injury or surgery and accounts for half of all cases of endophthalmitis. It causes clouded vision, eye pain, and reddened conjunctivae. Eventually, Aspergillus infects the anterior and posterior chambers, where it produces purulent exudate.
With disseminated aspergillosis, Aspergillus invades blood vessels and causes thrombosis, infarctions, and the typical signs and symptoms of septicemia (such as chills, fever, hypotension, and delirium), with azotemia, hematuria, urinary tract obstruction, headaches, seizures, bone pain and tenderness, and soft-tissue swelling. This form of the disorder is rapidly fatal.
In patients with aspergilloma, a chest X-ray reveals a crescent-shaped radiolucency surrounding a circular mass, but this isn’t definitive for aspergillosis. In patients with aspergillosis endophthalmitis, a history of ocular trauma or surgery and a culture or exudate showing Aspergillus supports the diagnosis. In patients with allergic aspergillosis, sputum examination shows eosinophils. Culture of mouth scrapings or sputum showing Aspergillus is inconclusive because even healthy persons harbor this fungus. In patients with disseminated aspergillosis, culture and microscopic examination of affected tissue can confirm the diagnosis, but this form is usually diagnosed at autopsy.
CLINICAL TIP: Itraconazole may be useful in slowing the progression of the disease in patients with immunocompetency.
Review other book chapters online related to Aspergillosis:
Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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Title: Handbook of Diseases Authors: Springhouse Publisher: Lippincott Williams & Wilkins Copyright: 2003 ISBN: 1-58255-266-5 
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