Aspergillosis

Definition:

An infection, colonization in the lung, or allergic response due to the aspergillus fungus.

Causes, incidence, and risk factors:

Aspergillosis is caused by a fungus (aspergillus), which is found commonly growing on dead leaves, stored grain, compost piles, or other decaying vegetation. It causes illness in three ways: as an allergic reaction in people with asthma (Pulmonary aspergillosis; allergic bronchopulmonary type); as a colonization in an old healed lung cavity from previous disease such as tuberculosis or lung abscess where it produces a fungus ball called aspergilloma; and as an invasive infection with pneumonia that is spread to other parts of the body by the blood stream (Pulmonary aspergillosis; invasive type). The invasive infection can affect the eye, causing blindness, and any other organ of the body, but especially the heart, lungs, brain, and kidneys. The third form occurs almost exclusively in people whose immune systems are suppressed from high doses of cortisone drugs, chemotherapy, or a disease that reduces the number of normal white blood cells. Those at risk are immunosuppressed people such as organ transplant recipients, and people with cancer, AIDS, or leukemia.