Respiratory Tract Infections (URI or URTI) are illnesses caused by an acute infection. This commonly includes nasal obstruction, sore throat, tonsillitis, pharyngitis, laryngitis, sinusitis, otitis media, and the common cold. Most infections are viral in nature and in other instances the cause is bacterial. Cystic Fibrosis (CF) respiratory tract is a common genetic disease whose major clinical manifestations include repeated episodes of airway infection and inflammation that ultimately result in premature death from respiratory failure. Fungal respiratory infections generate concern in the expanding population of immunosuppressed patients. Fungi may colonize body sites without producing disease or they may be a true pathogen, generating a broad variety of clinical syndromes. Fungal pneumonia is an infectious process in the lungs caused by one or more endemic or opportunistic fungi. Fungal infection occurs following the inhalation of spores, after the inhalation of conidia, or by the reactivation of a latent infection.