Keywords: ویروس پارا انفلوانزا انسانی; Acute exacerbation; Idiopathic interstitial pneumonia; Virus detection; Short term mortality; IPF; Non-IPF interstitial lung disease; BALF; bronchoalveolar lavage fluid; CMV; cytomegalovirus; CTD; connective tissue disease; HHV; human herpes virus; HMPV;