Aspergillosis is a group of illnesses caused by a certain type of mold. These illnesses usually affect the respiratory system. The mold that triggers the illnesses, aspergillus, occurs widely indoors and outdoors. Most strains of this mold are harmless. But a few can cause serious illnesses when their spores are inhaled by people with a weakened immune system, underlying lung disease or asthma.

In some people, the spores trigger an allergic reaction. Other people develop mild to serious lung infections. The most serious form of aspergillosis — invasive aspergillosis — occurs when the infection spreads to blood vessels and beyond.

Depending on the type of aspergillosis, treatment may involve observation, antifungal medications or, in rare cases, surgery.

Apr. 29, 2011