People inhale one kind, Aspergillus, all the time without any problem. It's nearly impossible to avoid, found in such places as decaying leaves, trees, grain, soil, household dust, heating ducts and building materials. The fungus can also cause skin infections if it enters a break in the skin.
The second kind, Exserohilum, is found in grass and rotting wood. When it causes disease, it's most commonly skin infection or inflammation in the sinuses.
Both were detected this week in patients with meningitis that occurred after a contaminated steroid was injected into the spinal column of some patients getting pain treatments. That provides a rapid way for fungus to cause a serious infection. It's not clear how the fungi got into the medication which was made by a specialty pharmacy.
Usually, after somebody inhales Aspergillus spores, they're destroyed by the body. But people with cystic fibrosis or asthma may have problems with it, wheezing and coughing. A more severe infection can arise in people with weakened immune systems, like those who've had transplant surgery or are getting chemotherapy for cancer. This invasive infection can cause fever, chest pain and shortness of breath.
Neither of those conditions spreads from person to person. It's hard to tell exactly how common Aspergillus infections are, but one study suggests it may affect just 1 or 2 people per 100,000 every year.
Federal information: http://www.cdc.gov/fungal/aspergillosis