Fungal infections of the Respiratory Tract are important causes of morbidity and mortality in immunocompromised hospitalized patients. Among these patients are those receiving cytotoxic chemotherapy for neoplastic diseases, those undergoing bone marrow stem cell transplantation or organ transplantation, and those affected with the acquired immune deficiency syndrome. Invasive Aspergillosis has been reported with increased frequency in parallel with an expanding population of immunocompromised patients. Other filamentous fungi, such as Fusarium spp., Zygomycetes, and Pseudallescheria boydii, are reported with increasing frequency, particularly in patients with quantitative or qualitative defects in neutrophils. Endemic mycoses, including those due to Histoplasma capsulatum, Coccidioides immitis, and Penicillium marneffei, have also been increasing in frequency in immunocompromised hosts in respevtive geographic regions.
In this section major clinical types of Aspergillosis including pulmonary Aspergillosis  which further classified as allergic, saprophytic, and invasive will be discussed.