Aspergillosis is caused by fungi of the Aspergillus genus, which are commonly found in soil and can grow in places like air vents. The most common disease-causing species are A. fumigatus, A. niger, and A. flavus. There are three main types of pulmonary aspergillosis: allergic reactions, aggressive tissue invasion, and fungus balls in pre-existing lung cavities. Aspergillus is diagnosed through culture, which can take 1-3 weeks to grow, or detection of antibodies. Treatment involves antifungal medications like voriconazole, fluconazole, and itraconazole.