The genius aspergillus is a Fungus extremely common throughout the world. It is in the air almost everywhere, and it’s estimated that most people breathe hundreds of Aspergillus spores into their lungs daily. It affects almost exclusively people with compromised immune systems or with underlying respiratory illness.
COMPROMISED IMMUNITY is often present in people with diabetes, obesity and malnutrition, The very young and very old, Viral infections, particularly AIDS and Covid, cancer, autoimmune diseases, organ transplants, and the list goes on. With the advances in medicine in the past few decades, people are being kept alive longer, often by suppressing their own immunity.

UNDERLYING REPIRATORY ILLNESS is disease such as asthma, cystic fibrosis, sarcoidosis, tuberculosis and COPD.
When I was in an allergy practice, we were always on the alert for allergic bronchopulmonary aspergillosis in asthmatics who were difficult to control. ABPA at that time was reported mainly in England, which is unsurprising due to the wet British climate: fungi grow especially well where is wet.
Another unusual phenomenon is the Aspergillus fungus ball in the lungs, which is sometimes discovered only by chest x-ray. That such a dense mass of fungi could be tolerated in the lungs without invading the body is a tribute to the immune system‘s efficacy.
Galactomannan is in the cell wall of aspergillus, and can be used as a diagnostic test. PCR can also be used, shades of COVID-19. Of course x-ray, or microscopic study of tissues are also often used.
It is estimated that aspergillosis accounts for around 600,000 deaths annually. Africa, with its large number of AIDS patients, contributes heavily to this. It’s difficult to know how common it is in the United States, because aspergillus is not a reportable illness. Please check with the following mayo clinic article for more information.