The Centers for Disease Control and Prevention (CDC) reports that aspergillosis is a disease caused by a common type of fungus, known as Aspergillus, which lives indoors and outdoors. While the CDC states that most people breathe in Aspergillus spores every day without getting sick, people with a weakened immune system or lung disease are at a higher risk of developing health problems due to exposure.
There are multiple types of aspergillosis, including:
• Allergic bronchopulmonary aspergillosis (ABPA)
• Allergic Aspergillus sinusitis
• Chronic pulmonary aspergillosis
• Invasive aspergillosis
• Cutaneous aspergillosis
Aspergillosis is not a reportable infection in the United States so the exact number of cases that occur is difficult to determine. The CDC does report that milder, allergic forms of aspergillosis are more common than the invasive form of the infection. The agency states that there are approximately 180 species of Aspergillus, but fewer than 40 of them are known to cause infections in humans. Of these, Aspergillus fumigatus is the most common cause of human infections, while other common species include A. flavus, A. terreus and A. niger.
The incubation period for aspergillosis is unclear and likely varies depending on the dose of Aspergillus and the host’s immune response. Exposure to indoor environments that have suffered water damage, or elevated humidity levels that have supported the growth of Aspergillus, can be an exposure concern for some building occupants. Hospital-acquired infections (HAIs) may also be associated with dust exposure during building renovation or construction.